choosing wisely canada. a healthy...

When it comes to your health, more medical tests, treatments and procedures are not always better. In fact, sometimes they’re unnecessary. Find out when you need medical tests, treatments and procedures — and when you don’t.

Talk with your doctor or visit ChoosingWiselyCanada.org

@ChooseWiselyCA

Choosing Wisely Canada. A healthy conversation.

choosing wisely-e.indd 1 13.06.2014 12:12 PM

Canadian Association of General SurgeonsCanadian Society for Vascular SurgeryCanadian Society of Surgical Oncology

Canadian Association of Thoracic SurgeonsDepartment of Surgery, Western University

Department of Surgery, Dalhousie University

Department of Surgery, University of AlbertaDepartment of Surgery, University of CalgaryDépartement de chirurgie, Université de SherbrookeDepartment of Surgery, McMaster UniversityDépartement de chirurgie, Université de Montréal

SponSorS

Vol. 57, No. 5, October/octobre 2014canjsurg.ca

An innovative paradigm for surgical education programs in resource-limited settings

Decreased heart rate variability in surgeons during night shifts

Inconsistencies between navigation data and x-rays in total knee arthroplasty are system-dependent and affect coronal alignment

Surgical management of symptomatic hydatid liver disease: experience from a Western centre

covercjs-oct14.indd 3 14-09-16 11:00 AM

CAREER/CLASSIFIED ADVERTISING CARRIÈRES ET ANNONCES CLASSÉES

The Canadian Journal of Surgery is pleased to accept career/classified advertisements. The deadline is 1 month before issue date.

Rates: Display ads: 1 page $1200; 2/3 page $900; 1/2 page vert/horiz $800; 1/3 page $650; 1/4 page $500; 1/6 page $400. Word ads: $120 for the first 40 words or less, additional words $1.20 each (additional $25 for frame). Special Display under 100 words, 55 × 55 mm, $205. $20 charge (first insertion only) for CJS confidential reply box numbers.

VISA, MASTERCARD AND AMERICAN EXPRESS ACCEPTED.

Advertisements should be sent to: Journal Advertising, Canadian Journal of Surgery, 1867 Alta Vista Dr., Ottawa ON K1G 5W8; tel 800 663-7336 or 613 731-8610 x2107/2041; fax 613 565-7488; email [email protected]

Send all box number replies to: Box . . . , Canadian Journal of Surgery, 1867 Alta Vista Dr., Ottawa ON K1G 5W8.

The Ontario Human Rights Code prohibits discriminatory employ ment advertising.

Le Journal canadien de chirurgie accepte volontiers les annonces sur les carrières et annonces classées. Celles-ci doivent être reçues au JCC au plus tard 1 mois avant la date de parution.

Tarifs: Grand format: 1 page 1200 $; 2/3 page 900 $; 1/2 page vert/horiz 800 $; 1/3 page 650 $; 1/4 page 500 $; 1/6 page 400 $. Mot des annonces: 120 $ jusqu’à 40 mots et 1.20 $ par mot supplémentaire (25 $ pour encadrement au trait). Encadré spécial jusqu’à 100 mots, 55 × 55 mm, 205 $. L’emploi d’une boîte-réponse confidentielle au JCC donne lieu à la perception d’un supplément de 20 $ (pour la première insertion seulement).

VISA, MASTERCARD ET AMERICAN EXPRESS ACCEPTÉS.

Le texte des annonces doit être adressé à : Annonces publicitaires, Journal canadien de chirurgie, 1867, prom. Alta Vista, Ottawa (Ontario) K1G 5W8; tél 800 663-7336 ou 613 731-8610 x2107/2041; fax 613 565-7488; courriel [email protected]

Veuillez faire parvenir les réponses au numéros de boîtes à l’adresse suivante : Boîte . . . , Journal canadien de chirurgie, 1867, prom. Alta Vista, Ottawa, (Ontario) K1G 5W8.

Le Code des droits de la personne de l’Ontario interdit la dis crimi nation dans la publicité relative à l’emploi.

ACADEMIC MOHS SURGEON CLINICIAN-SCHOLAR

Queen’s Department of Medicine, Division of Dermatology, is seeking a Mohs surgeon to join their group.

This is a full-time academic position. The incumbent will assist the Division in fulfilling its Clinical and Academic mission within the Department of Medicine.

Clinical responsibilities include Mohs surgical cases and associated skin cancer clinics. Limited on-call general dermatology service for urgent cases may be required.

The incumbent will participate in undergraduate and post-graduate teaching, as well as continuing medical education. Teaching will be a combination of clinical/surgical teaching for undergraduate and postgraduate learners as well as some lectures. The position will have 15% time protected for academic activity. Protected time for research is possible for candidates that have demonstrated a program of basic or clinical research.

Members of the Department of Medicine enjoy a competitive compensation package, including a generous benefit plan. Academic rank will be commensurate with experience.

Candidates must be eligible for licensure in the Province of Ontario and preference will be given to those who either hold or are eligible for certification by the Royal College of Physicians and Surgeons of Canada in Internal Medicine or the American Board of Specialties.

One of Canada’s leading universities, Queen’s has a long reputation for academic excellence, research, and a diverse and vibrant learning environment. With its strong tradition of public service, the University has helped to shape Canadian values and policies, educating notable political and cultural figures. Queen’s is located in the heart of the community in historic Kingston, midpoint between Montreal, Toronto and Ottawa, the nation’s capital.

Applications, which are to include a letter summarizing expertise, qualifications and accomplishments relevant to the position together with a curriculum vitae and the names and full contact information of three referees, are to be directed to:

Dr. S.L. Archer, Professor and Head, Department of Medicine c/o Jennifer Andersen

Etherington Hall, 94 Stuart Street Kingston, Ontario K7L 3N6

Email [email protected]

Review of applications will commence September 15, 2014 and will continue until the position is filled.

Queen’s is committed to employment equity and diversity in the workplace and welcomes applications from women, visible minorities, Aboriginal people, persons with disabilities, and persons of any sexual orientation or gender identity. All qualified candidates are invited to apply; however, Canadian citizens and permanent residents will be given priority.

The University will provide support in its recruitment processes to applicants with disabilities, including accommodation that takes into account an applicant’s accessibility needs. If you require accommodation during the interview process, please contact: Mrs. Jennifer Andersen, email [email protected]

S-7

59

classifiedcjs-oct14.indd 1 14-09-16 10:03 AMcovercjs-oct14.indd 4 14-09-16 11:00 AM

canjsurg.ca

© 2014 Canadian Medical Association Can J Surg, Vol. 57, No. 5, October 2014 289

EDITORIAL • ÉDITORIAL

294 Closer to private health care options? E.J. Harvey

295 Se rapprocherait-on de modèles de soins de santé privés ? E.J. Harvey

COMMENTARY • COMMENTAIRE

296 C. Barber Mueller: appreciation J. Meakins

298 An innovative paradigm for surgical education programs in resource-limited settings D.L. Deckelbaum, A. Gosselin-Tardif, G. Ntakiyiruta, S. Liberman, M. Vassiliou, E. Rwamasirabo, E. Gasakure, P. Fata, K. Khwaja, T. Razek, P. Kyamanywa

RESEARCH • RECHERCHE

300 Decreased heart rate variability in surgeons during night shifts I. Amirian, L.T. Andersen, J. Rosenberg, I. Gögenur

305 Inconsistencies between navigation data and radiographs in total knee arthroplasty are system-dependent and affect coronal alignment A. Carli, A. Aoude, A. Reuven, B. Matache, J. Antoniou, D.J. Zukor

314 Management of the open abdomen using combination therapy with ABRA and ABThera systems A.N. Mukhi, S. Minor

320 Surgical management of symptomatic hydatid liver disease: experience from a Western centre G. Martel, S. Ismail, A. Bégin, F. Vandenbroucke-Menu, R. Lapointe

327 Comparison of stable and unstable pertrochanteric femur fractures managed with 2- and 4-hole side plates R.P. Baird, P. O’Brien, D. Cruickshank

331 Laparoscopic right hemicolectomy with complete mesocolic excision provides acceptable perioperative outcomes but is lengthy — analysis of learning curves for a novice minimally invasive surgeon G. Melich, D.H. Jeong, H. Hur, S.H. Baik, J. Faria, N.K. Kim, B.S. Min

337 The clinical importance of different localizations of the papilla associated with juxtapapillary duodenal diverticula B. Ozogul, G. Ozturk, A. Kisaoglu, B. Aydinli, M. Yildirgan, S.S. Atamanalp

342 Factors affecting transfusion requirement after hip fracture: Can we reduce the need for blood? S.J. Desai, K.S. Wood, J. Marsh, D. Bryant, H. Abdo, A.-R. Lawendy, D.W. Sanders

349 Emergency surgery for colorectal cancer does not result in nodal understaging compared with elective surgery S.V. Patel, S.V.B. Patel, M. Brackstone

DISCUSSIONS IN SURGERY DISCUSSIONS EN CHIRURGIE

354 Trauma Non-Technical Training (TNT-2): the development, piloting and multilevel assessment of a simulation-based, interprofessional curriculum for team-based trauma resuscitation A.G. Doumouras, I. Keshet, A.B. Nathens, N. Ahmed, C.M. Hicks

356 Percutaneous drainage of Morel-Lavallée lesions when the diagnosis is delayed B. Zhong, C. Zhang, C.-F. Luo

Vol. 57, No. 5, October/octobre 2014canjsurg.ca

contentscjs-oct14.indd 289 14-09-16 11:01 AM

290 J can chir, Vol. 57, No 5, octobre 2014 © 2014 Association médicale canadienne

EVIDENCE-BASED SURGERY

358 Is early transfusion of plasma and platelets in higher ratios associated with decreased in-hospital mortality in bleeding patients? A.W. Kirkpatrick, C.G. Ball, J. Duchesne, K. Pavenski; Evidence Based Reviews in Surgery Group

297 CORRECTION

E149 ONLINE CORRESPONDENCE CORRESPONDANCE EN LIGNGE

IBC CAREER/CLASSIFIED ADVERTISING ANNONCES SUR LES CARRIÈRES ET ANNONCES CLASSÉES

© 2014 Canadian Medical Association. ISSN 0008-428X. For information on permission to reproduce material from the Canadian Journal of Surgery (CJS) see canjsurg.ca.

All editorial matter in CJS represents the opinions of the authors and not necessarily those of the Canadian Medical Association (CMA). The CMA does not assume any responsibility or liability for damages arising from any error or omission or from the use of any information or advice con-tained in CJS, including articles, editorials, reviews, letters and advertise-ments. All reproduction rights are reserved.

Printed by Dollco Integrated Print Solutions, Ottawa. Appears in February, April, June, August, October and December.

Return undeliverable Canadian copies to the CMA Member Service Centre, 1870 Alta Vista Dr., Ottawa ON K1G 6R7 (email [email protected]).

© 2014 Association médicale canadienne. ISSN 0008-428X. Pour obtenir des renseignements au sujet des permissions à obtenir afin de reproduire des extraits du Journal canadien de chirurgie (JCC), consulter canjsurg.ca.

Tous les articles à caractère éditorial dans le JCC représentent les opi nions de leurs auteurs, qui ne sont pas nécessairement celles de l’Asso ciation médicale canadienne (AMC). L’AMC n’assume aucune respon sabilité pour les dommages résultant de toute erreur ou omission, ou de l’utilisation de ren-seignements ou de conseils contenus dans le JCC, y compris les articles, éditoriaux, revues, lettres et annonces. Tous droits de reproduction réservés.

La revue est imprimée par Dollco Integrated Print Solutions, Ottawa. Elle paraît en février, avril, juin, août, octobre et décembre.

Retournez toutes copies canadiennes non livrées au Centre des ser vices aux membres, Association médicale canadienne, 1870, prom. Alta Vista, Ottawa (Ontario) K1G 6R7 (courriel : [email protected]).

contentscjs-oct14.indd 290 14-09-16 11:01 AM

COEDITORS CORÉDACTEURS

Edward J. Harvey, MD, Montréal [email protected]

Major Vivian C. McAlister, MB, London [email protected]

ASSOCIATE EDITORS RÉDACTEURS ASSOCIÉS

BASIC SCIENCE AND SURGICAL BIOLOGYIan McGilvray, MD, PhD, Toronto Timothy Daniels, MD, Toronto

BREAST SURGERYMuriel Brackstone, MD, London

CARDIOVASCULAR SURGERYMichel Carrier, MD, Montréal Michael Chu, MD, London

CRITICAL CARERaymond Kao, MD, London

ENDOCRINE SYSTEMSam Wiseman, MD, Vancouver

EVIDENCE-BASED MEDICINEMichelle Ghert, MD, Hamilton

GASTROINTESTINAL AND COLORECTAL SURGERYMarcus Burnstein, MD, Toronto Jason Park, MD, Winnipeg

GLOBAL SURGERYDan Deckelbaum, MD, Montréal

GENERAL SURGERYDaniel Birch, MD, Edmonton

HEPATOBILIARY AND PANCREATIC SURGERYShiva Jayaraman, MD, Toronto

MEDICAL EDUCATIONCarol Hutchison, MD, Calgary

MILITARY MEDICINEHomer Tien, MD, Toronto

ORTHOPEDIC FOOT AND ANKLE SURGERYKarl-André Lalonde, MD, Ottawa

ORTHOPEDIC SURGERYGraham Elder, MD, Sault Ste. Marie

PEDIATRIC SURGERY, GENERALSigmund Ein, MD, Toronto

PEDIATRIC SURGERY, ORTHOPEDICJames G. Wright, MD, MPh, Toronto

SPINAL SURGERYRaja Rampersaud, MD, Toronto

SPORTS MEDICINEPaul Martineau, MD, Montréal

SURGICAL ONCOLOGYGeoff Porter, MD, Halifax

SURGICAL ONCOLOGY, MUSCULOSKELETALFrank O’Dea, MD, St. John’s

SURGICAL ONCOLOGY, SOFT TISSUEChris de Gara, MB MS, Edmonton

THORACIC SURGERYJohn Yee, MD, Vancouver

TRAUMA SURGERY, ORTHOPEDICWilliam Dust, MD, Saskatoon

TRAUMA SURGERY, SOFT TISSUEMary vanWijngaarden-Stephens, MD, Edmonton Morad Hameed, MD, Vancouver

VASCULAR SURGERYKent Mackenzie, MD, Montréal

EDITORIAL STAFF ÉQUIPE DE RÉDACTION

MANAGING EDITOR DIRECTRICE DE LA RÉDACTIONWendy Carroll ([email protected]) tel 800 663-7336 (Canada, USA) or 613 731-8610 x2198; fax 613 565-5471

EDITORIAL COORDINATOR COORDONNATRICE DE LA RÉDACTIONElisa Makadi ([email protected]) tel 800 663-7336 (Canada, USA) 613 731-8610 x2018; fax 613 565-5471

TRANSLATION • TRADUCTIONMarie Saumure

PRODUCTION STAFF ÉQUIPE DE PRODUCTION

PRODUCTION MANAGER GESTIONNAIRE DE LA PRODUCTIONDebbie Rupert

PRODUCTION DESIGNERS INFOGRAPHISTES DE LA PRODUCTIONCarole Lalonde, Sarah O’Neill, Jennifer Pershick, Clara Walker

WEB PUBLISHERS ÉDITION EN LIGNEJames Harbinson, James Manship

ADVERTISING PUBLICITÉ

ADVERTISING ANNONCES PUBLICITAIRESLaurie McLeod, Susan Ritchie, David Bertrand 613 731-8610 x2107/2041 fax 613 565-7488 [email protected]; [email protected]

ADVERTISING SALES VENTES PUBLICITAIRESBlair Graham ([email protected]) 416 850-1485; cell 416 560-0202; fax 416 850-2242

Trish Sullivan ([email protected]) cell 905 330-8770

PUBLISHING STAFF ÉQUIPE DES SERVICES D’ÉDITION

DIRECTOR AND PUBLISHER, CMA PUBLICATIONS DIRECTRICE ET ÉDITRICE, PUBLICATIONS AMCGlenda Proctor

ASSOCIATE DIRECTOR, PUBLICATIONS DIRECTRICE ASSOCIÉE, PUBLICATIONSHolly Bodger

PROGRAM MANAGER, JOURNALS GESTIONNAIRE DE PROGRAMMES, JOURNAUXJanis Murrey

CMA EXECUTIVES DIRIGEANTS DE L’AMC

PRESIDENT • PRÉSIDENTChris Simpson

SECRETARY GENERAL AND CEO SECRÉTAIRE GÉNÉRAL ET CHEF DE LA DIRECTIONTim Smith

VP, PROFESSIONAL SERVICES AND LEADERSHIP VP, SERVICES PROFESSIONNELS ET LEADERSHIPDeborah Scott-Douglas

The Canadian Journal of Surgery aims to contribute to the effective continuing medical education of Canadian surgical specialists, and to provide surgeons with an effective vehicle for the dissemination of observations in the areas of clinical, basic science and education research.Readers can find CJS online at canjsurg.ca.Submission of new manuscripts can be made at http://mc.manuscriptcentral.com/cjs.

Le Journal canadian de chirurgie vise à dispenser une éducation médicale continue efficace aux spécialistes en chirurgie au Canada, et fournir aux chirurgiens un mécanisme efficace pour diffuser les constatations de la recherche clinique, fondamentale et éducative.Les lecteurs trouveront en direct le JCC à l’adresse canjsurg.ca.Nous favorisons l’envoi électronique de manuscrits. Veuillez visiter le http://mc.manuscriptcentral.com/cjs.

All prescription drug advertisements have been cleared by the Pharmaceutical Advertising Advisory Board.Toutes les annonces de médicaments prescrits ont été approuvés par le Conseil consultatif de publicité pharmaceutique.

Owned and published by CMA 1867 prom. Alta Vista Dr.

Ottawa ON K1G 5W8


masthead-oct14.indd 291 14-09-16 2:15 PM

The new cma.ca — see how simple searches can be.

Optimized mObilized persOnalized

Access relevant evidence-based information with a single search Working closely with CMA members, we’ve rebuilt our website to better serve physicians’ needs. The new cma.ca delivers enhanced clinical search capabilities and personalized content. Accessible on any mobile device, it’s your go-to source for knowledge resources, national advocacy on health and health care, and the CMAJ. Questions? Comments? Email [email protected], call 888-855-2555 or @CMA_Members. We’re listening.

“Like most physicians, time is a critical factor in almost every decision I make. The new cma.ca allows me to search quickly across multiple tools for the most relevant clinical information.”

dr. naheed dosani palliative care physician, toronto, Ont. Cma member

cma.ca/new

2511

cma.ca/newThe new cma.ca — see how relevant a website can be.


“There is a lot to be excited about with the new cma.ca. You’ll be able to search more effectively, save time and see relevant resources used most often by your colleagues.”

dr. andrea Kermack internist, montréal, Que. Cma member

Anytime, anywhere access to information that matters to youWorking closely with CMA members, we’ve rebuilt our website to better serve physicians’ needs. The new cma.ca delivers enhanced clinical search capabilities and personalized content. Accessible on any mobile device, it’s your go-to source for knowledge resources, national advocacy on health and health care, and the CMAJ. Questions? Comments? Email [email protected], call 888-855-2555 or @CMA_Members. We’re listening.

THE NEW cma.ca OPTIMIZED. MOBILIZED. PERSONALIZED.

edit-oct14.indd 292 14-09-16 11:00 AM

The new cma.ca — see how simple searches can be.


Access relevant evidence-based information with a single search Working closely with CMA members, we’ve rebuilt our website to better serve physicians’ needs. The new cma.ca delivers enhanced clinical search capabilities and personalized content. Accessible on any mobile device, it’s your go-to source for knowledge resources, national advocacy on health and health care, and the CMAJ. Questions? Comments? Email [email protected], call 888-855-2555 or @CMA_Members. We’re listening.

“Like most physicians, time is a critical factor in almost every decision I make. The new cma.ca allows me to search quickly across multiple tools for the most relevant clinical information.”

dr. naheed dosani palliative care physician, toronto, Ont. Cma member

cma.ca/new

2511

cma.ca/newThe new cma.ca — see how relevant a website can be.


“There is a lot to be excited about with the new cma.ca. You’ll be able to search more effectively, save time and see relevant resources used most often by your colleagues.”

dr. andrea Kermack internist, montréal, Que. Cma member

Anytime, anywhere access to information that matters to youWorking closely with CMA members, we’ve rebuilt our website to better serve physicians’ needs. The new cma.ca delivers enhanced clinical search capabilities and personalized content. Accessible on any mobile device, it’s your go-to source for knowledge resources, national advocacy on health and health care, and the CMAJ. Questions? Comments? Email [email protected], call 888-855-2555 or @CMA_Members. We’re listening.

THE NEW cma.ca OPTIMIZED. MOBILIZED. PERSONALIZED.

edit-oct14.indd 293 14-09-16 11:00 AM


Closer to private health care options?

T he lawsuit that was supposed to settle whether Canadian citizens have the right to timely health care has been delayed.1 Brian Day, former presi-

dent of the Canadian Medical Association, had initially brought a lawsuit in 2009 to allow his private clinic to exist. A small group of his patients joined him in 2012. The hearing was supposed to commence in September 2014. Since 2012, lawyers on both sides have swelled the process, with dozens of witnesses expected. The lawsuit is expected to take several months to play out. Apparently both sides wanted the delay in order to attempt settling some of the issues out of court. The complexity of the overall case has become overwhelming; however, the in itial events that led to the patient portion of the lawsuit seem to be plainly simple. The care of 2 patients with can-cer and 2 others with musculoskeletal ailments removing them from normal daily activities were being held up by long wait times. The patients just wanted to get on with a normal life or live what little time they had left off of a wait list. The British Colombia government did not agree with that.

Other attempts in Canada to find an alternative path-way are not being accepted by all those involved. A pro-posed class action suit in Quebec2 has seen a private citi-zen bringing a suit against physicians allegedly charging unreasonable amounts for local anesthesia or eye drops. This suit should never have been necessary. Doctors try-ing to deliver care outside the constrictive envelope of the current health care structure may be charging large amounts for medications or actions that are not on the formulary. Physicians trying to pay the overhead for their clinic space may just be attempting to find ways to stay afloat in the face of government opposition to any outside care options despite the Chaoulli judgment of 2005.3 Forcing the physicians into this position is unfair to everyone — patients and doctors alike.

It has become painfully obvious that the health care system is broken. Rising demand and increasingly expen-sive incremental medical and technological advances are pushing the boundary of affordability and safety in our current health care programs. We as a people no longer

have access to timely health care, particularly in surgery. Period. Certainly smaller and smaller pockets of surgeons still have an ability to treat patients — but this is no lon-ger the rule. More and more studies show that timely care is cost-efficient4 — and not just for conditions asso-ciated with high mortality. Operating on the walking wounded promptly takes away the wounded adjective and allows a return to normal life. The BC lawsuit judgment will hopefully determine whether we can have an alterna-tive pathway without prosecuting physicians or patients trying to speed up patient care. It will not mean the end of the current social health care system. I think we need to have options. The current amount of money being spent on health care by our governments is unsustainable. If we do not propose options now, we will not have a rec-ognizable health care system much longer. It would be nice if there was a timely judgment on the Brian Day case, but it seems mired in bureaucracy — as much bureaucracy as the health care system it is examining.

Edward J. Harvey, MD Coeditor, Canadian Journal of Surgery

Competing interests: None declared.

DOI: 10.1503/cjs.011814

References

1. Shaw R. Dr. Brian Day’s health lawsuit against the B.C. government over private care delayed. Vancouver Sun 2014 Aug 22. Available: www.vancouversun.com/health/Brian+health+lawsuit+against+government+over+private+care+delayed/10142047/story.html (accessed 2014 Sept. 1).

2. Class action suit targets extra medical fees. CTV Montréal 2014 May 16. Available: http://montreal.ctvnews.ca/class-action-suit-targets -extra-medical-fees-1.1825791 (accessed 2014 Sept. 1).

3. Chaoulli v. Quebec (Attorney General) 2005 SCC 35. Available: www.canlii.org/en/ca/scc/doc/2005/2005scc35/2005scc35.html (acces sed 2014 Sept. 1).

4. Ruiz D Jr, Koenig L, Dall TM, et al. The direct and indirect costs to society of treatment for end-stage knee osteoarthritis. J Bone Joint Surg Am 2013;95:1473-80.


edit-oct14.indd 294 14-09-16 11:00 AM



Se rapprocherait-on de modèles de soins de santé privés?

O n a reporté l’audition de la cause dont l’issue était censée nous permettre de savoir si les citoyens canadiens ont droit à des soins de santé

dans des délais raisonnables1. En 2009, le Dr Brian Day, un ancien président de l’Association médicale cana-dienne, avait intenté une poursuite pour obtenir le droit de conserver sa clinique privée. Quelques-uns de ses patients se sont joints à la poursuite en 2012. L’audition devait commencer en septembre 2014. Depuis 2012, le nombre de témoins n’a cessé d’augmenter pour chaque partie. On en prévoit des dizaines. Le procès devrait durer plusieurs mois. Les 2 parties auraient demandé un report pour permettre le règlement hors cour de cer-taines questions. La cause est devenue d’une complexité décourageante. Les événements à l’origine sont pourtant très simples. Deux patients atteints d’un cancer et 2 autres aux prises avec une maladie musculosquelet-tique nuisant aux activités quotidiennes normales fai-saient face à une longue attente avant d’obtenir des soins. Ils ne souhaitaient rien d’autre que de mener une vie normale ou du moins de vivre le temps qu’il leur restait sans croupir sur des listes d’attente. Le gouverne-ment de la Colombie-Britannique, lui, ne voyait pas le problème du même œil.

Au Canada, d’autres tentatives visant à trouver des solutions de rechange ne sont pas bien reçues par tout le monde. Au Québec, un recours collectif2 a été proposé par un citoyen contre des médecins en pratique privée qui fac-tureraient des honoraires déraisonnables pour une anes-thésie locale ou l’application de gouttes ophtalmiques. Un tel recours n’aurait jamais dû être nécessaire. Certains médecins qui tentent de fournir des services en dehors du cadre contraignant du régime de soins de santé actuel fac-turent peut-être des honoraires élevés pour des médica-ments ou des interventions non inscrits au formulaire. Certains essaient peut-être de trouver des façons de payer les frais généraux de leurs cliniques ou des moyens de rester à flot malgré l’opposition du gouvernement à toute solution permettant l’accès à des soins dans le privé et ce, malgré le jugement Chaoulli de 20053. Acculer les méde-cins à cette position est injuste pour tout le monde, tant les médecins que les patients.

Il est devenu trop évident que notre système de santé ne fonctionne plus. La demande croissante et les avancées médicales et technologiques de plus en plus coûteuses qui se multiplient repoussent les limites de l’abordabilité et de la sécurité de nos programmes de

soins de santé actuels. L’accès à des soins de santé dans des délais raisonnables n’est plus possible, surtout en chirurgie. Un point c’est tout. Certains chirurgiens, en nombres de plus en plus limités, arrivent toujours à traiter les patients, mais ce n’est plus la règle. De plus en plus d’études montrent que les soins de santé fournis dans des délais raisonnables sont rentables4 — et pas seulement pour des maladies associées à un taux de mor-talité élevé. En opérant rapidement un blessé ambula-toire, on élimine un malade et on permet au patient de reprendre une vie normale. Le jugement qui sera rendu dans la poursuite en Colombie-Britannique permettra, espérons-le, de savoir si une voie de rechange est possi-ble, sans poursuivre les médecins ou les patients qui essaient d’accélérer le traitement des malades. Cela ne marquera pas la fin de notre système public de santé actuel. Mais, à mon avis, il faut avoir des choix. Il n’est plus viable pour nos gouvernements de continuer à assumer les coûts actuels des soins de santé. Si des solu-tions ne sont pas trouvées dès maintenant, notre système de santé deviendra rapidement méconnaissable. Souhai-tons que l’affaire Brian Day ne tarde pas à se conclure, mais elle semble enlisée dans la bureaucratie autant que le système de santé qu’elle doit examiner.

Edward J. Harvey, MD Co-rédacteur, Journal canadien de chirurgie

Intérêts concurrents : Aucuns déclarés.

DOI: 10.1503/cjs.012114

Références

1. Shaw R. Dr. Brian Day’s health lawsuit against the B.C. government over private care delayed. Vancouver Sun, le 22 août 2014. Disponible : www.vancouversun.com/health/Brian+health+lawsuit+against+government+over+private+care+delayed/10142047/story.html (con sulté le 1 sept. 2014).

2. Class action suit targets extra medical fees. CTV Montréal, le 16 mai 2014. Disponible : http://montreal.ctvnews.ca/class-action-suit-targets -extra-medical-fees-1.1825791 (consulté le 1 sept. 2014).

3. Chaoulli c. Québec (Procureur général) 2005 CSC 35. Disponible : http://scc-csc.lexum.com/scc-csc/scc-csc/fr/item/2237/index.do (con sulté le 1 sept. 2014).

4. Ruiz D Jr, Koenig L, Dall TM, et al. The direct and indirect costs to society of treatment for end-stage knee osteoarthritis. J Bone Joint Surg Am 2013;95:1473-80.

edit-oct14-fr.indd 295 14-09-16 10:59 AM



C. Barber Mueller: Appreciation

C . Barber Mueller was a re mar k able person. It is a great pleasure to reintroduce

Barb to Canadian surgeons in recog-nition of his contributions to the Canadian Journal of Surgery and to surgery at McMaster University in Hamilton, Ont., in Canada and in the United States.

Barb was marked for a significant career from the time of his entry, on scholarship, to Medicine at Wash-ington University in St. Louis, Mo; his membership in the Alpha Omega Alpha fraternity; his role as the last chief resident of Evarts Graham; and his role as an initial Markle Scholar with numerous pub-lications in basic science journals. In medical school, his first paper was

with Evarts Graham as his coauthor. Following internship, Barb served with distinction in the Pacific Theatre with the 4th U.S. Marine Division, partici-pating in landings on 4 islands, including Iwo Jima, and winning the Bronze Star for meritorious service while being wounded twice. After finishing his resi-dency in 1951, Barb joined the faculty at Washington University School of Medicine. At age 39, he became professor and chair of surgery at the State University of New York in Syracuse. In 1967, he moved to McMaster Univer-sity and was integral to the planning and development of the novel “problem-based curriculum” as well as the planning and design of the medical centre.

Education was Barb’s passion. Indeed, he viewed himself “an educator by profession and a surgeon by trade.” Those who had the pleasure of being his guest as visiting professors also discovered, occasionally to their chagrin, that Barb had an uncanny ability to ask the key question that tested their presented research. I experienced his puckish sense of humour, clinical acumen and insight as he honed in on any weakness in my Grand Round or his evening case discussions with the students. Working with Barb was an educational experience for everyone. Five years after he retired, the students at McMaster awarded him the Student Teaching Excellence Award — a clear reflection of his devotion to them and his ongoing involvement after retirement from official positions. He brought that same educational drive to CJS.

Jonathan Meakins, OC, MD, DSc

Accepted for publication July 16, 2014

Correspondence to: J. Meakins 1509 Sherbrooke St. W, Apt. 21 Montréal QC H3G 1M1 [email protected]

DOI: 10.1503/cjs.009114

This commentary was written in memory of C. Barber Mueller, who died at age 97 on Feb. 13, 2014. He was coeditor in chief of CJS from 1972 to 1992.

Summary

mueller-meakins.indd 296 14-09-16 10:55 AM

COMMENTARY

Can J Surg, Vol. 57, No. 5, October 2014 297

Retirement simply brought a reorientation of his inter-ests — almost a lateral arabesque — as he founded The Friends of the Health Sciences Library and personally made significant contributions to the McMaster library. His contri-bution was so great that the university has created an elegant space within the library, The C. Barber Mueller History of Health and Medicine Room. The university has honoured him with an Emeritus Professorship, inducted him into the Faculty of Heath Sciences Community of Distinction and given him an honorary degree (his third).

Most of us would have been tired out at this point, but Barb, remembering his chief, Evarts Graham, finished his biography, Evarts A. Graham: The Life and Times of the Sur gical Spirit of St. Louis, in 2002. The title is an interesting reflection on Lindbergh’s airplane and Graham’s independ ent and innovative leadership in sur-gery. At age 94, Barb completed another work, Excalibur:

the Sword of Science that Reshaped the World, which was published in 2012.

On a personal note, I have many fond memories of my meetings with Barb. The most memorable was one in which I was a visitor to his teaching exercises with the stu-dents. Barb was a great role model, and I left feeling better than when I arrived. In preparing this commentary, I was delighted to find that Barb had contributed a chapter to my grandfather’s text, Practice of Medicine, on the electron microscopy of the kidney. Barb and I met at least twice a year at the American Surgical and the American College meetings. I always left our visits feeling good about things; he had that way about him. He was always most interested in who he was talking with and with his lively sense of humour, bringing out the best in all those around him.


CorreCtion

The article entitled “Low-intensity pulsed ultrasonography versus electrical stimulation for fracture healing: a sys-tematic review and network meta-analysis,” published in June 2014 (Can J Surg 2014;57(3):E105-18), contained errors in references 35 and 39. The correct references are 35. Heckman JD, Ryaby JP, McCabe J, et al. Acceleration of tibial fracture-healing by non-invasive, low-intensity pulsed ultrasound. J Bone Joint

Surg Am 1994;76A:26-34.39. Mayr E, Rudzki MM, Rudzki M, et al. Does pulsed low-intensity ultrasound accelerate healing of scaphoid fractures? Handchir Mikrochir Plast

Chir 2000;32: 115-22.

mueller-meakins.indd 297 14-09-16 10:55 AM



An innovative paradigm for surgical education programs in resource-limited settings

The burden of surgical disease in low-income countries remains significant, in part owing to continued surgical workforce shortages. We describe a successful paradigm to expand Rwandan surgical capacity through the implementation of a surgical education partnership between the National University of Rwanda and the Centre for Global Surgery at the McGill University Health Centre. Key considerations for such a program are highlighted.

Dan L. Deckelbaum, MD, MPH* Alexandre Gosselin-Tardif, MD† Georges Ntakiyiruta, MD‡ Sender Liberman, MD* Melina Vassiliou, MD, MEd* Emile Rwamasirabo, MD‡ Emmanuel Gasakure, MD‡ Paola Fata, MD, MSc* Kosar Khwaja, MD, MBA, MSc* Tarek Razek, MD* Patrick Kyamanywa, MD, MPH‡

From *McGill University Health Centre, Centre for Global Surgery, Montréal, Que., †McGill University, Faculty of Medicine, Montréal, Que., and the ‡National University of Rwanda, Depart-ment of Surgery, Kigali, Rwanda

Accepted for publication Jan. 31, 2014

Correspondence to: D.L. Deckelbaum Centre for Global Surgery McGill University Health Centre Montreal General Hospital Trauma Centre 1650 Cedar Ave. Montréal, QC H3G 1A4 [email protected] www.mcgill.ca/globalhealth/ www.cglobalsurgery.com

DOI: 10.1503/cjs.001514

Summary

I n recent years, there has been an important shift in the practice of global surgery. The traditional paradigm, which once consisted in large part of service-provision missions involving temporary transfers of resources, has

been supplemented, and in many instances replaced, by building long-term partnerships meant to augment local capacity. The latter is seen as the super i- or approach for tackling the substantial surgical disease burden and workforce needs of low- and middle-income countries (LMICs).1,2

In a combined effort to tackle these challenges, a partnership was created in 2010 between the National University of Rwanda (NUR) and the Centre for Global Surgery at the McGill University Health Centre (CGS-MUHC). Its aim is to augment Rwanda’s surgical workforce, which in 2010 stood at 12 general surgeons for a population of 11 million, by expanding the academic component of the country’s only existing and mostly service-based general surgery program.3

Following a joint needs assessment, an original system-based curriculum was created. The curriculum is centred on 2-week modules covering locally relevant general surgery topics, with Canadian surgeons who have relevant expertise functioning as moderators for the modules. Each module contains 6 hours of didactic lectures, 2 hours of case presentation, 2 hours of morbidity and mortality rounds and 1 hour of module evaluations, with operative teach-ing provided on elective operating room (OR) days and emergency cases. From program implementation in January 2011 to January 2014, 21 modules have been completed.

At the core of this project lie the concepts of local accountability and in itiative. Importantly, this partnership stems from an invitation from Rwandan surgical leaders, allowing for a targeted intervention based on local needs rather than Western models and expectations. This principle extends beyond the program’s initial conception, as its core, day-to-day operations are also under local governance. For this reason, Canadian sur-geons have clearly defined responsibilities as moderators and educators, are responsible for only 2 of the 6 didactic lectures scheduled and are never asked to perform the clinical or academic responsibilities of local faculty or trainees, who remain jointly responsible for each module. In addition, their role is meant to be progressively effaced as current residents graduate and become educators, leading to gradual independence from foreign presence and strengthened local surgical capacity. This trend can already be seen in the continued implementation of academic activities during periods without Canadian presence.

innova-deckel.indd 298 14-09-16 10:57 AM

COMMENTARY


Another prime concern for both partner organizations was to conduct early, context-appropriate and longitud-inal assessments of the new project. As highlighted in a recent Lancet editorial, within the spectrum of activities conducted as part of global health initiatives, program evaluation is often “only an afterthought.”4 As a result, the relevance and outcomes of international interventions run the risk of being presumed rather than proven, and valuable input from local partners remains uncollected and unimplemented.5 To avoid this development, an evaluation process was implemented at program onset. Initial evaluation consisted of an 8-item questionnaire distributed to Rwandan residents after every module. On review of their feedback, the questionnaire was replaced with a more critical 31-item survey. Further expansion led to the creation of a 36-item questionnaire addressed to participating Canadian surgeons. The issues surveyed range from curricular relevance, skill appropriateness and project logistics to cooperation between partners, oper-ating experience and research collaboration. By involving local and international partners as both developers and participants of this evaluation process, we hope to not only encourage changes favourable to all parties, but also to secure partnership sustainability by fostering shared ownership of and responsibility for the project.

An important component of our approach to cre-ating relevant, setting-specific evaluation instruments is that they be constructed alongside the program and subsequently adjusted and expanded as the program evolves. For this purpose, the initial resident question-naire was limited in scope, serving mainly to confirm residents’ acceptance of the curriculum and to provide qualitative feedback that would help identify shortcom-ings and issues important to participants. This informa-tion was used both to increase program quality and to expand and fine-tune existing evaluation tools, leading to the creation of larger and more relevant question-naires, whose quantitative items now addressed newly recognized themes. In this manner, the frequent inabil-ity of residents to attend teaching activities owing to large clinical workload was identified and consequently addressed by instituting dedicated academic days; this adaptation resulted in an average 31% increase in attendance. Similarly, on learning that 65% of Rwan-dan residents desired increased operative teaching, this curricular component was expanded; this process was based largely on recommendations subsequently sub-mitted in Canadian faculty questionnaires. A feedback loop was thus created in which program assessment serves to both improve the partnership and the evalua-tion tools themselves.

In addition to improving the learning experience of Rwandan residents, this program addresses one of the major obstacles to health care provision in LMICs: workforce retention. On completion of their studies, up

to 22% of graduates from sub-Saharan medical schools migrate outside the continent, most commonly owing to financial considerations and to lack of postgraduate training in nations of origin.6 Mature, in-country post-graduate training programs are more likely to reduce the need for foreign training while also generating locally relevant skill sets, augmenting the social account-ability of trainees and providing potential hiring oppor-tunities in education. The increase in the number of resi dents from 15 in 2010 to 21 in 2012 is encouraging in this respect.

Finally, this partnership further discounts previous cost-related misconceptions regarding global surgery that may have contributed to the prolonged lack of support for surgical interventions in sub-Saharan Africa.7 Efficient use of funds concentrates resources on Rwandan output rather than on donor administrative costs and income replace-ment, maintaining high educational benefits for the rela-tively low cost of Can$2140.24 per module, with the NUR covering housing costs and the CGS-MUHC cov-ering travelling costs.

Successful capacity-building paradigms are essential to tackle the burden of disease arising from injury and surgical illnesses in LMICs. Educational programs tar-geting local health care professionals at early stages of their careers are the cornerstone of such success. Our experience in building a surgical education partnership suggests that such a paradigm can enhance the success, vitality and longevity of like-minded capacity-building endeavours.Competing interests: D. Deckelbaum, G. Ntakiyiruta and P. Kyamanywa have received travel support from McGill University Health Centre. S. Liberman has received payment from Covidien for service on speakers’ bureaux. T. Razek is a board member (unpaid) for the Canadian Network for International Surgery.

Contributors: All authors have, at various stages, participated in the creation, implementation and evaluation of the surgical training pro-gram described in this commentary. Each author has also contributed to the design, drafting or editing of this commentary.

References

1. Tollefson TT, Larrabee WF. Global surgical initiatives to reduce the surgical burden of disease. JAMA 2012;307:667-8.

2. Farmer PE, Kim JY. Surgery and global health: a view from beyond the OR. World J Surg 2008;32:533-6.

3. Deckelbaum DL, Ntakiyiruta G, Liberman AS, et al. Augmenting surgical capacity in resource-limited settings. Lancet 2012;380:713-4.

4. Evaluation: the top priority for global health. Lancet 2010;375:526.5. Buekens P, Keusch G, Belizan J, et al. Evidence-based global

health. JAMA 2004;291:2639-41.6. Arah OA, Ogbu UC, Okeke CE. Too poor to leave, too rich to

stay: developmental and global health correlates of physician migra-tion to the United States, Canada, Australia and the United King-dom. Am J Public Health 2008;98:148-54.

7. Laxminarayan R, Chow J, Shahid-Salles SA. Intervention cost- effectiveness: overview of main messages. In: Jamison DT, Breman JG, Measham AR, et al., editors. Disease Control Priorities in Developing Coun-tries. 2nd ed. New York (NY): Oxford University Press; 2006: 35–86.

innova-deckel.indd 299 14-09-16 10:57 AM



Decreased heart rate variability in surgeons during night shifts

Background: Heart rate variability (HRV) has been used as a measure of stress and mental strain in surgeons. Low HRV has been associated with death and increased risk of cardiac events in the general population. The aim of this study was to clarify the effect of a 17-hour night shift on surgeons’ HRV.

Methods: Surgeons were monitored prospectively with an ambulatory elec-trocardiog raphy device for 48 consecutive hours, beginning on a precall day and con-tinuing through an on-call (17-h shift) day. We measured HRV by frequency domain parameters.

Results: We included 29 surgeons in our analysis. The median pulse rate was decreased precall (median 64, interquartile range [IQR] 56–70 beats per minute [bpm]) compared with on call (median 81, IQR 70–91 bpm, p < 0.001). Increased high-frequency (HF) activity was found precall (median 199, IQR 75–365 ms2) com-pared with on call (median 99, IQR 48–177 ms2, p < 0.001). The low-frequency:high-frequency (LF:HF) ratio was lower precall (median 2.7, IQR 1.9–3.9) than on call (median 4.9, IQR 3.7–6.5, p < 0.001). We found no correlation between the LF:HF ratio and performance in laparoscopic simulation.

Conclusion: Surgeons working night shifts had a significant decrease in HRV and a significant increase in pulse rate, representing sympathetic dominance in the autonomic nervous system.

Trial registration: NCT01623674 (www.clinicaltrials.gov).

Contexte : La variabilité de la fréquence cardiaque (VFC) a été utilisée comme mesure du stress et de l’effort mental chez les chirurgiens. On a établi un lien entre une faible VFC et la mort et le risque accru d’événement cardiaque dans la population générale. Cette étude visait à clarifier l’effet d’un quart de nuit de 17 heures sur la VFC des chirurgiens.

Méthodes : On a surveillé prospectivement des chirurgiens au moyen d’un appareil d’électrocardiographie ambulatoire pendant 48 heures consécutives en commençant la veille de la période de garde et durant toute la journée de garde (quart de 17 heures). Nous avons mesuré la VFC au moyen de paramètres du domaine fréquentiel.

Résultats : Notre analyse a porté sur 29 chirurgiens. Le pouls médian a diminué avant la période de garde (médiane de 64, plage interquartile [PIQ] de 56 à 70 battements/minute [b/m]) comparativement à la période de garde (médiane de 81, PIQ de 70 à 91 b/m, p < 0,001). On a constaté une activité de haute fréquence (HF) accrue avant la période de garde (médiane de 199, PIQ de 75 à 365 ms2) compara-tivement à la période de garde (médiane de 99, PIQ de 48 à 177 ms2, p < 0,001). Le ratio basses fréquences:hautes fréquences (BF:HF) était moins élevé avant (médiane de 2,7, PIQ de 1,9 à 3,9) que pendant la période de garde (médiane de 4,9, PIQ de 3,7 à 6,5, p < 0,001). Nous n’avons constaté aucun lien entre le ratio BF:HF et le rendement au cours d’une simulation de laparoscopie.

Conclusion : Les chirurgiens qui faisaient des quarts de nuit présentaient une dimi-nution importante de la VFC et une augmentation importante du pouls, ce qui représente une domination sympathique du système nerveux autonome.

Enregistrement de l’essai : NCT01623674 (www.clinicaltrials.gov).

Ilda Amirian, MD Lærke Toftegård Andersen, MD Jacob Rosenberg, DSc Ismail Gögenur, DSc

From the Department of Surgery, Herlev Hospital, University of Copenhagen, Her-lev, Denmark

Accepted for publication Feb. 7, 2014

Correspondence to: I. Amirian Department of Surgery Herlev Hospital, University of Copenhagen Herlev Ringvej 75, 2730 Herlev, Denmark [email protected]

DOI: 10.1503/cjs.028813

de-amirian.indd 300 14-09-16 11:00 AM

RESEARCH


Shifting work hours, sleep deprivation and stress have been shown to affect surgeon performance.1–3 At the same time, there is a negative effect on the health of

surgeons themselves.4 The negative effects are burnout and poor mental health.5–7 This stress induces changes in the auto-nomic nervous system that can be recorded noninvasively by an ambulatory electrocardiography (ECG) device with subse-quent statistical analysis of heart rate variability (HRV). Heart rate variability has been used as a measure of mental strain in surgeons performing laparoscopic versus conventional sur-gery8 and in surgeons performing laparoscopic surgery in modern operating rooms compared with standard ones.9 Fur-thermore, HRV has been used as a measure of stress in sur-geons before, during and after night shifts with a standardized resting period of 10 minutes.10 The HRV correlated with per-ceived stress, showing decreased stress levels during the night shift. A study by Nishi and colleagues11 stated that the lifespan of surgeons and obstetrician/gynecologists was shorter than that of physicians in basic medical sciences and internal medi-cine; the authors suggested that one of the reasons for this shorter lifespan was the degree of stress from work conditions. Furthermore, a systematic review and meta-analysis of 34 studies found that shift work was associated with increased risk of myocardial infarction and ischemic stroke.12 However, no increased mortality was associated with shift work.

Low HRV has a prognostic value in patients with myo-cardial infarction as a predictor of death and as a tool for risk stratification after myocardial infarctions.13 In the general population, low HRV has been associated with death and increased risk of cardiac events.14,15 To our knowledge, no previous study has investigated the development of HRV during an entire night shift among medical personnel. Our aim was to clarify the effect of a 17-hour night shift on surgeons’ HRV.

Methods

Design

Surgeons were monitored prospectively with an ambula-tory ECG device for 48 consecutive hours. The monitor-ing period started at 8 am on the morning precall and continued through the second day, on which the surgeons worked a 17-hour night shift from 3:30 pm to 8:30 am. The ECG monitoring was discontinued at 8 am on the morning postcall. Overall, the surgeons were monitored for psychomotor performance, cognition, circadian rhythm, sleep and fatigue over a period of 4 consecutive days. Data on psychomotor performance, cognition and sleep have been published separately.16

Participants

We included male and female interns, residents and attend-ing surgeons from an academic surgical department in a pro-

spective monitoring study. The participants did not work night shifts in the 72 hours preceding the study in order to avoid pre-existing sleep deprivation. They were instructed to get their habitual amount of nighttime sleep during this period. Furthermore, individuals receiving medical treatment for known endocrine, autoimmune or heart conditions were excluded, as were those with a previously diagnosed sleep dis-order. Pregnant or breastfeeding women were not included. Consumption of alcohol or stimulants in the 24 hours pre-ceding the study and during the study was not allowed. As we wished to monitor the surgeons in the habitual state, we did not restrict their intake of liquids containing caffeine.

HRV recording

We started a 48-hour ECG recording on the morning of the precall day, and recording continued through the on-call day. The ECG recording was discontinued on the morning postcall. We performed HRV monitoring using the Medilog AR12 recorder (Oxford Instruments Tubney Woods) with a 3-channel, 5-lead recording. We analyzed the HRV parameters using Medilog Darwin software (Huntleigh Healthcare). Mean values of short-term 5- minute recordings were manually viewed and excluded for noise, ectopy and missing beats; only normal-to- normal R waves were included to obtain reliable data. The normal-to-normal R waves are known as the NN interval. Only intervals with more than 90% valid data were included.

The parasympathetic (vagal) and sympathetic activity constantly interact. The vagal afferent stimulation leads to excitation of vagal efferent activity and, by reflex, inhibits sympathetic efferent activity.17 The opposite effects are mediated by the stimulation of sympathetic activity. The efferent vagal activity is a major contributor of high- frequency (HF) power. However, the interpretation of the low-frequency (LF) power is more controversial; some believe it represents sympathetic activity, whereas others argue it represents a parameter that includes both sympa-thetic and parasympathetic activity.17 In the present study, an increase of the LF power was used as a measure of sym-pathetic and parasympathetic activity,18,19 and HF power was used as a measure of increase in parasympathetic activ-ity.17,20 The LF:HF ratio was used as an index of the sympa-thovagal balance.19,21,22 An increase in this ratio represented a larger sympathetic influence on the HRV, and a decrease represented a larger vagal influence.

Data analysis

Analysis was performed according to the guidelines of the HRV task force.17 The HRV power spectra were calculated using fast Fourier transformation.17 Two main spectral com-ponents were distinguished: an LF component of 0.04–0.15 Hz and an HF component of 0.15–0.4 Hz. The power and frequency of each spectral component were calculated as


RECHERCHE

302 J can chir, Vol. 57, No 5, octobre 2014

absolute units (milliseconds squared). We measured heart rate from the mean NN values. The medians of the 5-minute intervals were determined for every hour. Then we deter-mined the medians of the hourly intervals from 4 pm to 8 am precall and on call for every participant.

Ethics and permissions

Our trial fully complied with the Helsinki declaration on biomedical research. The Danish Regional Committee on Biomedical Research Ethics evaluated and approved the trial (H-4–2011–095). The Danish Data Protection Agency approved the collection, analysis and storage of data (2011–41–6384). All participants gave their informed consent before inclusion in the study. Participation in the study was voluntary; all participants received 500 Danish kroner (equivalent to $90 USD) at the end of the study. The trial was registered at www.clinicaltrials.gov (NCT01623674).

Statistical analysis

We used SPSS software version 19.0 for data entry and statistical analysis. Group values are presented as medians and interquartile ranges (IQRs). We used the Wilcoxon test for paired intragroup comparisons and the Friedman test for repeated intragroup comparisons. We considered results to be significant at p < 0.05.

Results

Thirty surgeons participated in the study; however, we included the data for only 29 participants in our analyses. One surgeon was excluded because she received a diag-nosis of myxoedema 8 weeks after her participation in the study. Thus, the results are based on data from 9 interns, 11 residents and 9 attending surgeons. The median work experience was 5 (IQR 1–9) years. Participant characteris-tics are presented in Table 1.

The development of HF power from 4 pm to 8 am precall and on call is shown in Figure 1. We found a significant dif-ference in the development over time for both precall and on-call values. The median pulse rate is presented as a box plot in Figure 2A. The precall pulse rate was lower (median 64, IQR 56–70 beats per minute [bpm]) than the on-call pulse rate (median 81, IQR 70–91 bpm, p < 0.001). High-frequency activity is presented as a box plot in Figure 2B. The vagal activity was higher precall (median 199, IQR 75–365 ms2) than on call (median 99, IQR 48–177 ms2, p < 0.001). Fig. 2C illus-trates the LF:HF values as a measure of sympathovagal bal-ance, with a median of 2.7 (IQR 1.9–3.9) precall and 4.9 (IQR 3.7–6.5) on call (p < 0.001). There were no significant differences between precall values and on-call values in LF power (Fig. 2D). In order to account for differences in train-ing levels, we conducted subgroup analyses for the interns, residents and attending surgeons for the LF:HF ratio as a representative for the sympathovagal balance. No significant differences were found (Kruskal–Wallis test). In order to examine the association between HRV and performance in the laparoscopic simulator, we used the Spearman correla-tion test for the LF:HF ratio and performance for the precall and on-call day. Performance was measured as time in lapa-roscopic simulation, as this was the primary outcome of the overall study.16 No correlation was found between the LF:HF ratio and time in laparoscopic performance (precall: r = –0.20, p = 0.92; on call: r = –0.24, p = 0.20).

Table 1. The age, weight and height of the participants

Group; median (IQR)

Characteristic Men Women

Participants 16 13

Age, yr 34 (30–38) 37 (31–40)

Weight, kg 80 (77–85) 64 (56–69)

Height, cm 183 (180–187) 168 (165–171)

IQR = interquartile range.

Fig. 1. The development of high-frequency (HF) power from 4 pm to 8 am (16:00–08:00) for the precall and on-call days. Squares represent precall values with a p < 0.001. Circles represent on-call values with a p < 0.001. The p values were determined using the Friedman test. The decrease in HF power from 10 pm to 7 am (22:00–07:00) on call represents a decrease in vagal activity.

0

50

100

150

200

250

300

350

16:00–17:00

17:00–18:00

18:00–19:00

19:00–20:00

20:00–21:00

21:00–22:00

22:00–23:00

23:00–24:00

24:00–01:00

01:00–02:00

02:00–03:00

03:00–04:00

04:00–05:00

05:00–06:00

06:00–07:00

07:00–08:00

HF

pow

er, m

s2

PrecallOn call


RESEARCH


Discussion

Our results showed a change in the autonomic nervous sys-tem activity, with sympathetic dominance in the nighttime on-call values compared with precall values. The HF values were significantly increased on the precall night compared with the on-call night, demonstrating a higher vagal influ-ence (Figs. 1 and 2A). The surgeons had a significantly higher pulse rate (Fig. 2A) during the 17 hours they worked on a night shift, which supported the findings of sympathetic dominance of the autonomic nervous system activity while on call. The decrease in LF:HF ratio supported a larger vagal influence on the sympathovagal balance precall, and the increase in LF:HF ratio on call demonstrated a sympathetic dominance (Fig. 2C). However, the LF values did not differ significantly when precall values were compared with on-call values (Fig. 2D), possibly owing to LF values representing both vagal and sympathetic influence on the HRV. The overall findings may be explained solely by surgeons being awake overnight; still, the findings demonstrate physiologic stress regardless of surgeons’ training levels.

Our study also showed that surgeons had decreased HRV during on-call hours, as the vagal activity was significantly reduced. A previous study examined anesthesiologists, pedia-tricians and otolaryngologists and compared their HRVs from 9 pm to 10 pm after daytime work, on a night shift and on the day after a night shift.23 The study found decreased

HRV after daytime work and on a night shift in anesthesiolo-gists compared with the other specialists, indicating higher physiologic stress. The tasks of anesthesiologists can be com-pared with the tasks of surgeons, as both have a large work-load at night because acute situations may arise at all times.

It has been shown previously that low HRV from a 2-minute rhythm strip predicted increased mortality due to poor general health.24 The authors selected a random sam-ple of 900 patients without prevalent coronary heart dis-ease at baseline. The patients with low HRV determined from a 2-minute rhythm strip had an adverse cardiovascu-lar risk profile and elevated risk of death from all causes, including cancer. This may imply that the night shifts causing a reduced HRV and higher pulse rate in surgeons may have a negative impact on their general health in the long run and may cause increased mortality.

Surgeons’ stress and ways to reduce or cope with stress have been described previously. A study used an anonymous self-report questionnaire and a randomized response tech-nique (RRT), with a high degree of anonymity, to assess the use of prescribed or illicit drugs solely with the purpose of cognitive or mood enhancement among surgeons.25 Accord-ing to the questionnaire, 8.9% of surgeons reported that they had used drugs at least once, merely for cognitive enhancement; however, the RRT revealed a prevalence of 19.9%. For mood enhancement, 2.4% of the surgeons stated on the questionnaire that they had used antidepressants;

Fig. 2. (A) Median pulse rate from 4 pm to 8 am precall and on call (p < 0.001, Wilcoxon test). (B) High- frequency (HF) power from 4 pm to 8 am precall and on call (p < 0.001, Wilcoxon test). The median precall HF value was higher and had a wider interquartile range (IQR) than the on-call value, demonstrating a greater parasympathetic influence. (C) The LF:HF ratio as a measure of the sym-pathovagal balance from 4 pm to 8 am precall and on call (p < 0.001, Wilcoxon test). The decrease in the LF:HF ratio precall repre-sents a larger vagal influence, and the increase on call represents a larger sympathetic influence on heart rate variability. (D) Low- frequency (LF) power from 4 pm to 8 am precall and on-call (p = 0.39, Wilcoxon test). Boxes represent the IQRs. Lines within the boxes represent the medians. Whiskers represent minimum and maximum IQR values.

0

200

400

600

800

1000

1200

1400

1600

1800

2000

Low

fre

quen

cy p

ower

, ms2

0

200

400

600

800

1000

1200

1400

Hig

h fr

eque

ncy

pow

er, m

s2

0

2

4

6

8

10

12

Low

fre

quen

cy/h

igh

freq

uenc

y

0

20

40

60

80

100

120

Pul

se r

ate,

bpm

A B

C D

Precall On call

Precall On call Precall On call

Precall On call


RECHERCHE


again, the RRT revealed a higher prevalence (15.1%). The use of drugs is hardly recommended as a coping strategy for stress in surgeons. A study found that scheduled intraopera-tive breaks reduced surgeons’ cortisol levels by 22%, with-out prolonging the operation.26 A systematic review looking at residents’ health found 2 studies on protected sleep time to reduce residents’ fatigue.27 Further studies on scheduled breaks and protected sleep time with a focus on how sur-geons’ stress can be reduced are needed.

The strengths of the present study were that HRV moni-toring and analysis were performed continuously for the 17-hour periods of evening and nighttime both precall and on call, providing solid insight on the sympathovagal balance of the entire recording period. Unfortunately, we did not perform postcall HRV monitoring. This would have strengthened the study further, as it would have shown when a normalization of the sympathovagal balance took place.

ConClusion

Our study showed a significant decrease in HRV and a sig-nificant increase in pulse rate in surgeons working night shifts compared with nighttime hours off call. Future studies could investigate methods to reduce sympathetic dominance during night shifts, as the decreased HRV may be harmful to surgeons’ health.Acknowledgements: The study was financially supported by the Tryg Foundation and The Danish Medical Association. The sponsors played no role in the design and conduct of the study; collection, management, analysis and interpretation of the data; and preparation, review, or approval of the manuscript.


Contributors: I. Amirian, J. Rosenberg and I. Gögenur designed the study. I. Amirian and L. Andersen acquired the data, which all authors analyzed. I. Amirian and I. Gögenur wrote the article, which all authors reviewed and approved for publication.

References

1. Rothschild JM, Keohane CA, Rogers S, et al. Risks of complications by attending physicians after performing nighttime procedures. JAMA 2009;302:1565-72.

2. Taffinder NJ, McManus IC, Gul Y, et al. Effect of sleep deprivation on surgeons’ dexterity on laparoscopy simulator. Lancet 1998;352:1191.

3. Grantcharov TP, Bardram L, Funch-Jensen P, et al. Laparoscopic performance after one night on call in a surgical department: pro-spective study. BMJ 2001;323:1222-3.

4. Buddeberg-Fischer B, Klaghofer R, Stamm M, et al. Work stress and reduced health in young physicians: prospective evidence from Swiss residents. Int Arch Occup Environ Health 2008;82:31-8.

5. Tyssen R, Vaglum P, Gronvold NT, et al. The impact of job stress and working conditions on mental health problems among junior house officers. A nationwide Norwegian prospective cohort study. Med Educ 2000;34:374-84.

6. Cohen JS, Patten S. Well-being in residency training: a survey examin-ing resident physician satisfaction both within and outside of residency training and mental health in Alberta. BMC Med Educ 2005;5:21.

7. Shanafelt TD, Bradley KA, Wipf JE, et al. Burnout and self-

reported patient care in an internal medicine residency program. Ann Intern Med 2002;136:358-67.

8. Böhm B, Rotting N, Schwenk W, et al. A prospective randomized trial on heart rate variability of the surgical team during laparoscopic and conventional sigmoid resection. Arch Surg 2001; 136: 305-10.

9. Klein M, Andersen LP, Alamili M, et al. Psychological and physical stress in surgeons operating in a standard or modern operating room. Surg Laparosc Endosc Percutan Tech 2010;20:237-42.

10. Langelotz C, Scharfenberg M, Haase O, et al. Stress and heart rate vari-ability in surgeons during a 24-hour shift. Arch Surg 2008; 143:751-5.

11. Nishi M, Miyake H, Yamazoe M, et al. Life span of Japanese med-ical doctors. J Epidemiol 1999;9:315-9.

12. Vyas MV, Garg AX, Iansavichus AV, et al. Shift work and vasclar events: systematic review and meta-analysis. BMJ 2012;345:e4800.

13. Bigger JT, Fleiss JL, Rolnitzky LM, et al. The ability of several short-term measures of RR variability to predict mortality after myocardial infarction. Circulation 1993;88:927-34.

14. Tsuji H, Venditti FJ, Manders ES, et al. Reduced heart rate vari-ability and mortality risk in an elderly cohort. The Framingham Heart Study. Circulation 1994;90:878-83.

15. Dekker JM, Schouten EG, Klootwijk P, et al. Heart rate variability from short electrocardiographic recordings predicts mortality from all causes in middle-aged and elderly men. The Zutphen Study. Am J Epidemiol 1997;145:899-908.

16. Amirian I, Andersen LT, Rosenberg J, et al. Laparoscopic skills and cognitive function are not affected in surgeons during a night shift. J Surg Educ 2014;71:543-50.

17. Heart rate variability. Standards of measurement, physiological interpretation, and clinical use. Task Force of the European Society of Cardiology and the North American Society of Pacing and Elec-trophysiology. Eur Heart J 1996;17:354-81.

18. Yamamoto Y, Hughson RL, Peterson JC. Autonomic control of heart rate during exercise studied by heart rate variability spectral analysis. J Appl Physiol 1991;71:1136-42.

19. Pagani M, Lombardi F, Guzzetti S, et al. Power spectral analysis of heart rate and arterial pressure variabilities as a marker of sympatho-vagal interaction in man and conscious dog. Circ Res 1986;59:178-93.

20. DeBenedittis G, Cigada M, Bianchi A, et al. Autonomic changes during hypnosis: a heart rate variability power spectrum analysis as a marker of sympatho-vagal balance. Int J Clin Exp Hypn 1994; 42:140-52.

21. Bootsma M, Swenne CA, Van Bolhuis HH, et al. Heart rate and heart rate variability as indexes of sympathovagal balance. Am J Physiol 1994;266:H1565-71.

22. Pagani M, Mazzuero G, Ferrari A, et al. Sympathovagal interaction during mental stress. A study using spectral analysis of heart rate variability in healthy control subjects and patients with a prior myo-cardial infarction. Circulation 1991;83:II43-51.

23. Malmberg B, Persson R, Flisberg P, et al. Heart rate variability changes in physicians working on night call. Int Arch Occup Environ Health 2011;84:293-301.

24. Dekker JM, Crow RS, Folsom AR, et al. Low heart rate variability in a 2-minute rhythm strip predicts risk of coronary heart disease and mortality from several causes: the ARIC study. Atherosclerosis risk in communities. Circulation 2000;102:1239-44.

25. Franke AG, Bagusat C, Dietz P, et al. Use of illicit and prescription drugs for cognitive or mood enhancement among surgeons. BMC Med 2013;11:102.

26. Engelmann C, Schneider M, Kirschbaum C, et al. Effects of intra-operative breaks on mental and somatic operator fatigue: a random-ized clinical trial. Surg Endosc 2011;25:1245-50.

27. Reed DA, Fletcher KE, Arora VM. Systematic review: association of shift length, protected sleep time, and night float with patient care, residents’ health, and education. Ann Intern Med 2010;153:829-42.




Inconsistencies between navigation data and radiographs in total knee arthroplasty are system-dependent and affect coronal alignment

Background: Few studies have compared the effect of different computer navigation systems on postoperative alignment in patients who have had total knee arthroplasty (TKA). We examined 2 computed tomography (CT)–free computer navigation systems by comparing the accuracy of intraoperative measurements to postoperative alignment.

Methods: Patients underwent unilateral TKA performed by a single surgeon using 1 of 2 CT-free navigation systems. We compared final intraoperative tibial and femoral coronal angles and mechanical axis with the same angles measured on standing postop-erative radiographs.

Results: Groups of 31 and 50 patients underwent TKA with the 2 systems, respectively. We noted a significant difference in the coronal tibial implant angle (1.29º ± 1.35º) and in the mechanical axis (1.59º ± 2.36º) for one navigation system (both p < 0.001), while only the coronal tibial implant angle showed a significant difference (1.17º ± 1.65º, p < 0.001) for the second system. The number of radiographic outliers also significantly differed. A significantly higher proportion (32%; p < 0.01) of patients in the second cohort exhibited unacceptable malalignment compared with the first cohort (24%).

Conclusion: Navigation systems for TKA continue to increase in sophistication and popularity. Owing to the significant difference in the proportion of alignment outliers in the 2 navigation systems tested in this study, orthopedic surgeons should not consider all TKA navigation systems equivalent. Additional investigations are needed to compare the accuracy of a variety of CT-free and CT-based navigation systems and to confirm our finding that accuracy is system-dependent.

Contexte : Il existe peu d’études ayant comparé divers systèmes informatiques de naviga-tion de guidage servant à vérifier l’alignement postopératoire de l’articulation chez des patients ayant subi une arthroplastie totale du genou (ATG). On a évalué 2 systèmes de navigation de guidage sans base tomodensitométrique en comparant l’exactitude des mesures d’alignement intra-opératoires et celles des mesures postopératoires.

Méthodes : Des patients ont subi une ATG unilatérale, qui a été pratiquée par un seul chirurgien à l’aide de l’un des 2 systèmes de navigation de guidage sans base tomodensi-tométrique. On a comparé les mesures intra-opératoires finales de l’angle frontal de l’articulation tibiofémorale et de l’axe mécanique du genou aux angles mesurés sur les radiographies postopératoires en station debout.

Résultats : Un groupe de 31 patients et un groupe de 50 ont subi une ATG réalisée à l’aide des 2 systèmes respectivement. On a observé un écart significatif des mesures de l’angle frontal de l’embase tibiale de la prothèse (1,29 º ± 1,35º) et des mesures de l’axe mécanique du genou (1,59 º± 2,36 º) avec l’un des systèmes de navigation (avec les deux, p < 0,001), tandis qu’avec l’autre, on a observé seulement une différence appréciable des mesures de l’angle frontal de l’embase tibiale (1,17 º± 1,65 º, p < 0,001). On a aussi observé une grande variation du nombre d’aberrations radiographiques. Dans la deuxième cohorte, on a observé une proportion significativement plus importante (32 %; p < 0,01) de patients présentant un défaut d’alignement inacceptable que dans la première (24 %).

Conclusion : Les systèmes de navigation de guidage servant à réaliser les ATG ne ces-sent de se perfectionner et d’être de plus en plus prisés. Cependant, en raison de l’écart significatif de la proportion des défauts d’alignement dépistés entre les 2 systèmes de na vi gation testés au cours de cette étude, le chirurgien orthopédiste ne devrait pas croire que tous les systèmes sont équivalents. Il faudrait mener d’autres études pour comparer la précision de divers systèmes de navigation de guidage sans base tomodensitométrique à celle de systèmes à base tomodensitométrique pour corroborer notre constatation, c’est-à-dire que la précision dépend du système utilisé.

Alberto Carli, MD* Ahmed Aoude, MD* Avishai Reuven, MD† Bogdan Matache, MD* John Antoniou, MD, PhD† David J. Zukor, MD†

From the *Division of Orthopaedic Surgery, McGill University, Montréal, Que., and the †Division of Orthopaedic Surgery, Lady Davis Institute for Medical Research- Jewish General Hospital, McGill University, Montréal, Que.

Accepted for publication Mar. 5, 2014

Correspondence to: A. Carli Division of Orthopaedic Surgery McGill University 1529 Cedar Ave. Montréal QC H3G 1A6 [email protected]

DOI: 10.1503/cjs.031313

inconsist-carli.indd 305 14-09-16 10:58 AM

RECHERCHE


C omputer-assisted orthopedic surgery (CAOS) for total knee arthroplasty (TKA) is generally considered to lead to component positioning that is more accurate

and reproducible than conventional techniques.1,2 Additional advantages for the use of COAS in TKA include decreased perioperative blood loss owing to the avoidance of intra-medullary instrumentation,1,3–5 fewer postoperative thrombo-embolic events6 and fewer systemic emboli.7–9 Hoffart and colleagues10 also demonstrated that CAOS provides better clinical outcomes at 5 years than conventional TKA. Further-more, recent meta-analyses by Cheng and colleagues11 and Bauwens and colleagues12 demonstrated that using COAS for TKA significantly reduced the relative risk of excessive implant misalignment by 25% compared with conventional TKA. Another recent meta-analysis by Hetaimish and col-leagues13 showed that CAOS produced better implant align-ment in the coronal plane for both the tibial and femoral components as well as femoral and tibial slope than the con-ventional technique.

Although these investigations have demonstrated the improvement of component alignment with CAOS, they did not take into account a critical component of the operative procedure: the type of computer navigation system used. The only comparisons of alignment among different com-puter navigation systems have come from 2 studies that each compared a computed tomography (CT)–based system to a CT-free system.14,15 Given that studies used in the meta-analysis by Cheng and colleagues11 used a total of 6 different CT-free navigation systems and 2 CT-based systems while those used in the analysis by Bauwens and colleagues12 included 5 CT-free systems and 3 CT-based systems, further investigations are required to confirm that computer naviga-tion systems are equivalently accurate in measuring TKA alignment. Such investigations are especially needed in CT-free CAOS systems, whose differences in hardware and soft-ware design have been previously identified as a potential source of inaccuracy.16

The current gold standard for assessing the mechanical alignment of the lower extremity following TKA is the standing full lower extremity radiograph. Therefore, the ideal CAOS navigation system, when properly used, should provide intraoperative measurements for femoral and tibial cuts that match the final implant position and limb align-ment as measured on postoperative radiographs. Using this logic, it is possible to compare CAOS navigation systems with one another by assessing the difference between intra-operative alignment measurements by the CAOS system to actual postoperative radiographic alignment values. Thus, it can be said that the smaller the difference between intraop-erative and postoperative measurements, the more accurate the CAOS navigation system. The more accurate a CAOS navigation system is, the more confident the surgeon can be that measurements taken intraoperatively reflect the actual postoperative alignment. We have shown in previous work that angular measurements attained by a single CT-free

CAOS navigation system intraoperatively can differ signifi-cantly from postoperative measurements taken from full length lower extremity radiographs.17 The present study compares this initial system to a second CT-free CAOS navigation system in order to determine if one is more accu-rate overall and produces fewer alignment outliers (≥ 3° of varus/valgus alignment).

We hypothesized that the variation between final intraop-erative CAOS bony cut measurements and postoperative implant and extremity alignment would be different between the 2 CT-free navigation systems. We also hypothesized that the number of postoperative mechanical outliers (≥ 3º of varus/valgus) would be decreased for the navigation system that had more similar intraoperative and postoperative measures.

Methods

Patient selection

We retrospectively reviewed the medical records and radiographs for all consecutive patients who underwent CAOS-TKA at a single orthopedic institution in 2 time periods (November 2007–February 2008 and March 2009–December 2010). For the first cohort, all operations were performed with the assistance of the ORTHOsoft Knee 2.1 Universal system. For the second cohort, all operations were performed with the assistance of the Brainlab AG Ci Knee essential 2.1.1 system. All procedures were per-formed by a single arthroplasty surgeon (D.J.Z.) who received formal training for each navigation system. The specific time periods were selected for study evaluation as they represented the time by which the surgeon had sur-passed the accepted threshold for the learning curve (30–50 cases)18,19 of each CAOS-TKA system. Consecutive patient inclusion was performed to minimize selection bias.

Operative procedure and perioperative data collection

All procedures were performed under spinal anesthesia, and the surgeon used a medial parapatellar approach. On expos-ure of the knee joint, articular landmarks and important bone areas were recorded using a pointer-like device, and external optical tracking devices were placed on the tibia and femur to template bony cuts. The 2 imaging systems used similar static landmarks, including the femoral condylar sur-faces, centre of the talus, femoral intercondylar notch, bor-ders of the tibial plateau and tibial spine, as well as dynamic motions to determine the centre of the femoral head. The main difference in landmark identification was the need to trace out (or “paint”) the entirety of the distal femoral and proximal tibial articular surfaces with the Brainlab system compared with several single point landmarks on the ORTHOsoft system. Apart from these differences and slight instrument sizing differences, the 2 navigation systems


RESEARCH


similarly use optical trackers that provide data regarding knee position to an infrared receiver, which then displays real-time positional information on a digital display. Follow-ing navigation-assisted femoral and tibial cuts, trial com-ponents and a fitting spacer were placed, and knee range of motion was assessed. Following cement application and component placement, a final alignment assessment could be performed in both the Brainlab and ORTHOsoft sys-tems to allow any further alignment correction due to the cement mantle. Knee range of motion and mechanical axis were then clinically assessed, and the subcutaneous tissue and skin was closed with a Jones bandage.

Data were collected intraoperatively through each CT-free navigation system. For both systems, the following parameters were recorded after insertion of final components: the coronal angle of the tibial cut, the coronal angle of the femoral cut and the final mechanical axis of the lower extremity.

Postoperative data collection

As per standard protocol at our institution, all patients underwent a full weight-bearing long axis radiograph of the lower extremities 6 weeks after surgery. Standing radio-graphs were obtained using a long film cassette with a radi-ography tube distance of 305 cm to capture the hips, knees and ankles. Although use of a long cassette is not universal20 and is subject to errors due to knee flexion and lower extrem-ity rotation,21–23 its use has been cited as an acceptable refer-ence standard for alignment of the lower limb.24–27 Radio-graphs were then viewed in their native DICOM format using Horizon Rad Station viewing software version 11.0.8.2172 (McKesson). Measured values were obtained by 2 individuals (A.C. and B.M), who did not participate in any of the surgical procedures, were blinded to the CAOS system allocation and who were both experienced in taking radio-graphic measurements for research purposes. Using the same methodology as described in our previous work,17 the follow-ing measurements were obtained from postoperative radio-graphs: the coronal angle of the tibial component, the cor-on al angle of the femoral component and the final mechanical axis. Interrater reliability was calculated, and the average of each measurement made by the 2 researchers was then used for comparison. Furthermore, Knee Society scores were recorded for each patient at the 6-week visit.


We assessed interrater reliability for radiographic measure-ments by calculating the intraclass correlation coefficient using SPSS statistical software version 19, using a 2-way random-effects model assuming a single measurement and absolute agreement. An intraclass correlational coefficient of 1 represents perfect reliability, and any value greater than 0.8 indicates excellent reliability.28 We compared intraoperative navigation and postoperative radiographs using paired t tests,

with the level of significance set at p < 0.05. The proportions of postoperative complications and radiographic outliers were recorded for each system and compared using a χ2 test. A radiographic outlier was defined as a postoperative measure-ment of 3º of varus/valgus or greater.

Results

Our study included 81 patients: 31 in the ORTHOsoft group and 50 in the Brainlab group. All patients success-fully underwent unilateral TKA with no significant intraop-erative complications. Patient demographics were similar in both groups. The mean patient age was 70.12 ± 10.66 years in the ORTHOsoft group and 74.27 ± 7.60 years in the Brainlab group. All patients began weight bearing by the second postoperative day and yielded similar rates of post-operative transfusions (χ2 = 1.547, p = 0.21) and deep vein thrombosis (χ2 = 2.46, p = 0.11). No major complications, including deep wound infection, myocardial infarction and pulmonary embolus, were noted in either group during the first 6 weeks. The mean Knee Society score at 6 weeks was comparable between the groups (mean 67.77 ± 14.15 in the ORTHOsoft group v. 67.09 ± 12.32 in the Brainlab group). Overall, interrater reliability for postoperative radiograph measurements was excellent, with intraclass correlation coefficients of 0.834 for the coronal angle of the tibial com-ponent (p < 0.001), 0.842 for the coronal angle of the fem-oral component (p < 0.001) and 0.962 for the mechanical axis (p < 0.001).

We noted significant differences between intraopera-tive navigation measurements and postoperative radio-graph measurements in each navigation group (Table 1). However, such differences were not observed in the same measurements. In the ORTHOsoft group, we noted a significant difference in the coronal tibial implant angle (1.29º ± 1.35º, p < 0.001) and in the mechanical axis (1.59º ± 2.36º, p < 0.001). In the Brainlab group, only the coronal tibial implant angle showed a significant difference (1.17º ± 1.65º, p < 0.001); no differ-ence was observed in the mechanical axis (0.75º ± 2.67º, p = 0.05). In both groups, the coronal angle of the femur showed no significant change from intraoperative data to postoperative radiographs (0.30 ± 1.74, p = 0.33 in the ORTHOsoft group v. 0.22 ± 1.94, p = 0.49 in the Brain-lab group).

The number of radiographic outliers also differed in each navigation system. The overall percentage of patients with at least 1 radiographic parameter more than 3° was 32% (10 of 31) in the ORTHOsoft group and 24% (12 of 50) in the Brainlab group (χ2 = 19.121, p < 0.01). The per-centage of outliers was higher in the ORTHOsoft group for both the mechanical axis (29% v. 22%; Fig. 1) and the coronal angle of the femoral component (6.4% v. 6%; Fig. 2). The Brainlab group had a higher percentage of coronal tib-ial angle outliers (12% v. 9.6%; Fig. 3).


RECHERCHE


Discussion

Interest in comparing computer navigation systems in ortho-pedics is steadily emerging. Although not relevant to TKA, a

study by Honl and colleagues29 compared acetabular orienta-tion in 5 computer-assisted navigation systems for total hip arthroplasty and found variations among the systems. Spe-cific to TKA, Harvie and colleagues30 prospectively followed

Fig. 1. Comparison of intraoperative measurements of the mechanical axis measured by Brainlab and ORTHOsoft navigation systems and postoperative measurements on standing radiographs. Intraoperative navigation measurements are organized from the most valgus to most varus.

Brainlab value Radiograph

Deg

rees

V

algu

s V

arus

D

egre

es

Val

gus

Var

us

ORTHOsoft value Radiograph

8 7 6

5

4

3

2

1

0 –1

–2

–3

–4

–5

–6

–7

–8 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 50 23 24 25 26 27 28 29 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 30 31 32 21 22

8 7 6

5

4

3

2

1

0 –1

–2

–3

–4

–5

–6

–7

–8 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 23 24 25 26 27 28 29 30 31 21 22

Table 1. Comparison of intraoperative navigation measures and manual radiolographic measurements made 6 weeks after surgery for the Brainlab and ORTHOsoft navigation systems*

Group; mean ± SD

MeasureNavigation system

values Radiograph values Mean difference 95% CI p value

Brainlab, n = 50

Coronal plane of femoral implant 0.14 ± 0.95 0.35 ± 1.70 0.21 ± 0.75 –0.33 to 0.77 0.49

Coronal plane of tibial implant 0.59 ± 0.76 –0.58 ± 1.65 1.17 ± 0.89 –1.64 to –0.70 < 0.001

HKA angle 0.02 ± 0.70 –0.73 ± 2.69 0.75 ± 1.99 –1.51 to 0.01 0.05

ORTHOsoft, n = 31

Coronal plane of femoral implant 0.17 ± 0.63 0.48 ± 1.65 0.30 ± 1.74 –0.33 to 0.94 0.33

Coronal plane of tibial implant –0.66 ± 1.10 0.62 ± 1.78 1.29 ± 1.35 0.79 to 1.78 < 0.001

HKA angle 0.45 ± 1.20 2.04 ± 2.13 1.59 ± 2.36 0.73 to 2.46 < 0.001

CI = confidence interval; HKA = hip–knee–ankle; SD = standard deviation. *Positive measurements represent valgus orientation; negative measurements represent varus orientation. Comparison was made using a paired t test, with significance set at p < 0.05.


RESEARCH


40 patients who underwent the procedure using either an imageless full navigation system or an articular surface-mounted navigation system. They found no significant dif-ference between the 2 systems with regard to the postop-erative implant position verified. A comparison among imageless navigation systems has not been reported despite the general preference for CT-free over CT-dependent systems.

To our knowledge, the present study is the first to compare deviations between intraoperative navigation data and postoperative radiograph measurements of 2 CT-free navigation systems. It is also, to our knowledge, the first to propose that this form of intraoperative and postoperative comparison be used as a manner to measure accuracy for CAOS systems. Our results confirm our in itial hypothesis that the greater the difference between intraoperative navigation system measurements and post-operative radiograph measurements, the greater the inci-dence of coronal misalignment in patients who have undergone TKA. It should be specifically emphasized that

the differences between the 2 systems, although signifi-cant, were small and within 2° of each other. However, such small differences were enough to significantly change the overall proportion of radiographic outliers between systems, which is a pertinent finding given that one of the driving purposes of computer navigation in TKA was to eliminate knee malalignment. Since the difference between intraoperative and postoperative measurements was not the same for the 2 navigation systems studied, our results indicate that different CT-free navigation systems are not necessarily equivalent in predicting postoperative alignment during TKA.

Computed tomography–free navigation systems have been previously shown to decrease the prevalence of radiographic outliers to 10%.31–34 In our study, neither navigation system met this threshold. The navigation system that provided intraoperative measurements that better matched postoperative alignment (Brainlab) had fewer mechanical outliers (24%) than its less accurate counterpart (ORTHOsoft). This latter system produced

Fig. 2. Comparison of intraoperative measurements of the coronal orientation of the femoral implant measured by Brainlab and ORTHOsoft navigation systems and postoperative measurements on standing radiographs. Intraoperative navigation measurements are organized from the most valgus to most varus.


Deg

rees

V

algu

s V

arus

D

egre

es

Val

gus

Var

us


8 7 6

5

4

3

2

1

0 –1

–2

–3

–4

–5

–6

–7

–8 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 50 23 24 25 26 27 28 29 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 30 31 32 21 22

8 7 6

5

4

3

2

1

0 –1

–2

–3

–4

–5

–6

–7

–8 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 23 24 25 26 27 28 29 30 31 21 22


RECHERCHE


an incidence of mechanical outliers that surpassed the 30% rate seen with conventional instrumentation.35,36

Controversy exists in the literature regarding the clinical relevance of the improved coronal alignment attained through CAOSTKA. Khan and colleagues37 found that patients who underwent computerassisted TKA with a mechanical axis alignment of 3° or more from neutral had lower Western Ontario and McMaster Universities Arthritis Index scores, indicating increased difficulty with daily activities. Furthermore, Lützner and colleagues38 randomly assigned 80 patients to receive either conventional or navigated TKA and found that patients who underwent navigated TKA were less likely to have mechanical axis malalignment postoperatively and had significantly improved Knee Society scores. However, a followup study involving the same cohort revealed no difference between the groups 5 years after surgery.39 A similar result was found at a 2year followup of 71 patients who were also randomized to conventional or navigated TKA.40

In addition to findings of equivalent outcome scores despite improved alignment, concerns for higher revision rates after navigated TKA have been raised. Gotheson and colleagues41 presented data from the Norwegian registry regarding 10 000 TKAs and found significantly higher re visions rates for navigation versus conventional (3.6% v. 2.1%) procedures. However, this finding is offset by findings of equivalent revision rates in a comparison study of 100 navigated and conventional TKAs42 as well as a retrospective evaluation of 1121 TKAs that yielded a significantly lower revision rate for navigated TKAs.43 Although these conflicting findings in the literature raise valid concerns regarding the longterm benefits of navigated TKA, it remains generally accepted that establishing a normal mechanical axis is a fundamental technical objective in TKA and that CAOSTKA more reliably accomplishes this objective than conventional methods.44 However, findings from the present study indicate that some CAOSTKA systems may not be as reliable in providing intraoperative

Fig. 3. Comparison of intraoperative measurements of the coronal orientation of the tibial implant measured by Brainlab and ORTHOsoft navigation systems and postoperative measurements on standing radiographs. Intraoperative navigation measurements are organized from the most valgus to most varus.


Deg

rees

V

algu

s V

arus

D

egre

es

Val

gus

Var

us


8 7 6

5

4

3

2

1

0 –1

–2

–3

–4

–5

–6

–7

–8 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 50 23 24 25 26 27 28 29 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 30 31 32 21 22

8 7 6

5

4

3

2

1

0 –1

–2

–3

–4

–5

–6

–7

–8 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 23 24 25 26 27 28 29 30 31 21 22


RESEARCH


alignment information that adequately correlates with the postoperative mechanical axis. Ultimately, additional studies comparing multiple CAOS-TKA systems and how their respective divergences between intraoperative and postoperative alignment variables affect long-term clinical outcome must be performed to evaluate the relevance of the present findings.

Limitations

This study has limitations. Although the navigation data and postoperative radiograph measurements were taken prospectively, patients were not randomized to a specific navigation system. Preoperative alignment and range of motion data were not compared between the 2 groups, a notable limitation given that a previous study reported greater divergence between intraoperative and postopera-tive alignment indices in patients with more severe preop-erative alignment deformities.45 The study also does not provide short-term patient outcome information after the 6-week postoperative mark, making it difficult to deter-mine the clinical importance of the observed discrepancies between intraoperative and postoperative alignment. Although patients in both groups were included only after the learning curve for each CAOS system had been sur-passed, we acknowledge that the treating surgeon was more experienced in CAOS-TKA when performing sur-geries on the Brainlab cohort and that this may have improved his intraoperative alignment technique for this group. Postoperative radiograph measurements, although recorded by the 2 blinded observers with excellent inter-rater reliability, are inherently susceptible to errors due to patient positioning as well as knee flexion and external rotation.46–49 In addition, as remarked by Choi and col-leagues,50 intraoperative and postoperative measurements are performed under considerably different circumstances. Intraoperative measurements are taken before complete soft tissue closure in full extension and without weight bearing, whereas postoperative measurements are taken with full weight bearing and cannot control for soft tissue contractures elsewhere in the lower extremity.

Despite such differing circumstances, our inclusion of only a single surgeon performing the surgical procedures should minimize intersurgeon variation in how the intra-operative data were collected, making it less difficult to compare against postoperative radiographs. Furthermore, our choice to use long-cassette radiographs as the gold standard is justified, as this modality is considered an acceptable reference for alignment27 and sufficient for rou-tine postoperative assessment.51 Another consideration is the cement mantle, which if applied unevenly can cause the final implant position to be different from the bony cut. Both systems used in the present study permit intraopera-tive alignment after cement and components are inserted, permitting the surgeon to apply coronal stresses or impact

implants further before cement curing. This feature of final component alignment surveillance is not universal among CAOS-TKA systems and, along with various cementing techniques, could theoretically affect final com-ponent alignment. We are interested in evaluating the effect of cementing technique and CAOS final alignment capability, and we plan to perform a prospective evaluation at our centre. The slight difference in the way surface landmarks between the 2 systems were made is also of interest, but the effect this difference would have on align-ment is unknown and should also be recorded in future system comparisons. Finally, long-term data were not included, making it difficult to conclude if such variability in discrepancy between navigation data and radiograph measurements impacted clinical outcome.

ConClusion

Computer-assisted orthopedic surgery for TKA continues to increase in sophistication and popularity, with new computerized systems attempting to incorporate aspects of both full navigation and conventional TKA.30 Although a sizeable amount of literature exists advocating the advantages in alignment that accompanies the use of CAOS, results from the present study suggest that ortho-pedic surgeons should not consider all TKA navigation systems to be the same. Additional investigations are needed to compare the accuracy of a variety of CT-free and CT-based navigation systems and to confirm our finding that accuracy is system-dependent, with greater accuracy leading to fewer mechanical outliers. This find-ing should be taken into account when reviewing conflict-ing data obtained from pooled results involving different systems, and should also be considered when switching to different systems in clinical practice.Competing interests: None declared

Contributors: A. Carli, A. Aoude, A. Reuven, J. Antoniou and D. Zukor designed the study and acquired the data. A. Carli, B. Matache, J. Antoniou and D. Zukor analyzed the data. A. Carli, A. Aoude, A. Reuven, J. Antoniou and D. Zukor wrote the article, which A. Carli, B. Matache, J. Antoniou and D. zukor reviewed. All authors approved the final version for publication.

References

1. Chauhan SK, Scott RG, Breidahl W, et al. Computer-assisted knee arthroplasty versus a conventional jig-based technique. A ran-domised, prospective trial. J Bone Joint Surg Br 2004;86:372-7.

2. Decking R, Markmann Y, Fuchs J, et al. Leg axis after computer- navigated total knee arthroplasty: a prospective randomized trial comparing computer-navigated and manual implantation. J Arthroplasty 2005;20:282-8.

3. Kalairajah Y, Simpson D, Cossey AJ, et al. Blood loss after total knee replacement: effects of computer-assisted surgery. J Bone Joint Surg Br 2005;87:1480-2.


RECHERCHE


4. Bierbaum BE, Callaghan JJ, Galante JO, et al. An analysis of blood management in patients having a total hip or knee arthroplasty. J Bone Joint Surg Am 1999;81:2-10.

5. McConnell J, Dillon J, Kinninmonth A, et al. Blood loss following total knee replacement is reduced when using computer-assisted versus standard methods. Acta Orthop Belg 2012;78:75-9.

6. Ooi LH, Lo NN, Yeo SJ, et al. Does computer-assisted surgical navi-gation total knee arthroplasty reduce venous thromboembolism com-pared with conventional total knee arthroplasty? Singapore Med J 2008;49:610-4.

7. Kalairajah Y, Cossey AJ, Verrall GM, et al. Are systemic emboli reduced in computer-assisted knee surgery?: A prospective, ran-domised, clinical trial. J Bone Joint Surg Br 2006;88:198-202.

8. Morawa LG, Manley MT, Edidin AA, et al. Transesophageal echo-cardiographic monitored events during total knee arthroplasty. Clin Orthop Relat Res 1996; (331):192-8.

9. Church JS, Scadden JE, Gupta RR, et al. Embolic phenomena during computer-assisted and conventional total knee replacement. J Bone Joint Surg Br 2007;89:481-5.

10. Hoffart HE, Langenstein E, Vasak N. A prospective study compar-ing the functional outcome of computer-assisted and conventional total knee replacement. J Bone Joint Surg Br 2012;94:194-9.

11. Cheng T, Zhao S, Peng X, et al. Does computer-assisted surgery improve postoperative leg alignment and implant positioning follow-ing total knee arthroplasty? A meta-analysis of randomized controlled trials. Knee Surg Sports Traumatol Arthrosc 2012;20:1307-22.

12. Bauwens K, Matthes G, Wich M, et al. Navigated total knee replacement. A meta-analysis. J Bone Joint Surg Am 2007;89:261-9.

13. Hetaimish BM, Khan MM, Simunovic N, et al. PK Z. Meta-analysis of navigation vs conventional total knee arthroplasty. J Arthroplasty 2012;27:1177-82.

14. Martin A, von Strempel A. CT-based and CT-free navigation in total knee arthroplasty–a prospective comparative study with respects to clinical and radiological results [article in German]. Z Orthop Ihre Grenzgeb 2005;143:323-8.

15. Bäthis H, Perlick L, Luring C, et al. CT-based and CT-free naviga-tion in knee prosthesis implantation. Results of a prospective study [article in German]. Unfallchirurg 2003;106:935-40.

16. Stulberg SD, Loan P, Sarin V. Computer-assisted navigation in total knee replacement: results of an initial experience in thirty-five patients. J Bone Joint Surg Am 2002;84-A(Suppl 2):90-8.

17. Livshetz I, Brin Y.S., Holcroft C., et al. Deviations between intra-operative navigation data and post-operative weight-bearing X-rays. Comput Aided Surg 2010;15:56-62.

18. Jenny J-Y, Miehlke RK, Giurea A. Learning curve in navigated total knee replacement. A multi-centre study comparing experienced and beginner centres. Knee 2008;15:80-4.

19. Daubresse F, Vajeu C, Loquet J. Total knee arthroplasty with con-ventional or navigated technique: comparison of the learning curves in a community hospital. Acta Orthop Belg 2005;71:710.

20. Jiang C-C, Insall JN. Effect of rotation on the axial alignment of the femur: pitfalls in the use of femoral intramedullary guides in

total knee arthroplasty. Clin Orthop Relat Res 1989; (248):50-6.

21. Krackow KA, Pepe C, Galloway E. A mathematical analysis of the effect of flexion and rotation on apparent varus/valgus alignment at the knee. Orthopedics 1990;13:861.

22. Brouwer R, Jakma T, Brouwer K, et al. Pitfalls in determining knee alignment: a radiographic cadaver study. J Knee Surg 2007;20:210-5.

23. Hunt MA, Fowler PJ, Birmingham TB, et al. Foot rotational effects on radiographic measures of lower limb alignment. Can J Surg 2006;49:401.

24. Langenbach MR, Dohle J, Zirngibl H. Determination of the axis after total endoprosthesis of the knee: functional X-ray photog-raphy as golden standard [article in German]. Z Orthop Ihre Grenzgeb 2002;140:32-6.

25. Duparc J, Massare C. Radiological measurement of the angular deviation of the knee in the frontal plane [article in French]. Ann Radiol (Paris) 1967;10:635-6.

26. Reed SC, Gollish J. The accuracy of femoral intramedullary guides in total knee arthroplasty. J Arthroplasty 1997;12:677-82.

27. Cooke TDV, Sled EA, Scudamore RA. Frontal plane knee alignment: a call for standardized measurement. J Rheumatol 2007; 34:1796.

28. Fleiss J. Statistical methods for rates and proportions. 2nd ed. New York (NY): John Wiley and Sons; 1981.

29. Honl M, Schwieger K, Salineros M, et al. Orientation of the ace-tabular component: a comparison of five navigation systems with conventional surgical technique. J Bone Joint Surg Br 2006;88:1401.

30. Harvie P, Sloan K, Beaver RJ. Three-dimensional component alignment and functional outcome in computer-navigated total knee arthroplasty a prospective, randomized study comparing two navigation systems. J Arthroplasty 2011;26:1285-90.

31. Bäthis H, Perlick L, Tingart M, et al. Alignment in total knee arthroplasty. A comparison of computer-assisted surgery with the conventional technique. J Bone Joint Surg Br 2004;86:682-7.

32. Sparmann M, Wolke B, Czupalla H, et al. Positioning of total knee arthroplasty with and without navigation support. A prospective, randomised study. J Bone Joint Surg Br 2003;85:830-5.

33. Kim SJ, MacDonald M, Hernandez J, et al. Computer assisted naviga-tion in total knee arthroplasty: improved coronal alignment. J Arthroplasty 2005;20(Suppl 3):123-31.

34. Stöckl B, Nogler M, Rosiek R, et al. Navigation improves accuracy of rotational alignment in total knee arthroplasty. Clin Orthop Relat Res 2004; (426):180-6.

35. Bolognesi M, Hofmann A. Computer navigation versus standard instrumentation for TKA: a single-surgeon experience. Clin Orthop Relat Res 2005; (440):162-9.

36. Brys DA, Lombardi AV Jr, Mallory TH, et al. A comparison of intramedullary and extramedullary alignment systems for tibial component placement in total knee arthroplasty. Clin Orthop Relat Res 1991; (263):175-9.

37. Khan MM, Khan MW, Al-Harbi HH, et al. Assessing short-term functional outcomes and knee alignment of computer-assisted navi-gated total knee arthroplasty. J Arthroplasty 2012;27:271-7.

Change of addressWe require 6 to 8 weeks’ notice to ensure uninterrupted service. Please send your current mailing label, new address and the effective date of change to:

CMA Member Service Centre

1870 Alta Vista Dr.Ottawa ON K1G 6R7

tel 888 855-2555 or 613 731-8610 x2307 fax 613 [email protected]

Changement d’adresseIl nous faut de 6 à 8 semaines d’avis afin de vousassurer une livraison ininterrompue. Veuillez faireparvenir votre étiquette d’adresse actuelle, votrenouvelle adresse et la date de la prise d’effet duchangement, à l’attention du

Centre des services aux membres de l’AMC

1870, prom. Alta VistaOttawa ON K1G 6R7

tél 888 855-2555 ou 613 731-8610 x2307 fax 613 [email protected]


RESEARCH


38. Lützner J, Günther K-P, Kirschner S. Functional outcome after computer-assisted versus conventional total knee arthroplasty: a randomized controlled study. Knee Surg Sports Traumatol Arthrosc 2010;18:1339-44.

39. Lützner J, Dexel J, Kirschner S. No difference between computer-assisted and conventional total knee arthroplasty: five-year results of a prospective randomised study. Knee Surg Sports Traumatol Arthrosc 2013;21:2241-7.

40. Spencer JM, Chauhan SK, Sloan K, et al. Computer navigation versus conventional total knee replacement: no difference in functional results at two years. J Bone Joint Surg Br 2007;89:477-80.

41. Gøthesen O, Espehaug B, Havelin L, et al. Short-term outcome of 1,465 computer-navigated primary total knee replacements 2005-2008: A report from the Norwegian Arthroplasty Register. Acta Orthop 2011;82:293-300.

42. Lüring C, Kauper M, Bäthis H, et al. A five to seven year follow-up comparing computer-assisted vs freehand TKR with regard to clin-ical parameters. Int Orthop 2012;36:553-8.

43. Schnurr C, Güdden I, Eysel P, et al. Influence of computer navigation on TKA revision rates. Int Orthop 2012;36:2255-60.

44. Mason JB, Fehring TK, Estok R, et al. Meta-analysis of alignment outcomes in computer-assisted total knee arthroplasty surgery. J

Arthroplasty 2007;22:1097-106.

45. Rauh MA, Boyle J, Mihalko WM, et al. Reliability of measuring long-standing lower extremity radiographs. Orthopedics 2007; 30:299-303.

46. Lonner JH, Laird MT, Stuchin SA. Effect of rotation and knee flexion on radiographic alignment in total knee arthroplasties. Clin Orthop Relat Res 1996;(331):102-6.

47. Wong AK, Inglis D, Beattie KA, et al. Reproducibility of computer-assisted joint alignment measurement in OA knee radio-graphs. Osteoarthritis Cartilage 2009;17:579-85.

48. Schmidt GL, Altman GT, Dougherty JT, et al. Reproducibility and reliability of the anatomic axis of the lower extremity. J Knee Surg 2004;17:141-3.

49. Cooke TD, Sled EA, Scudamore RA. Frontal plane knee align-ment: a call for standardized measurement. J Rheumatol 2007; 34:1796-801.

50. Choi WC, Lee S, An JH, et al. Plain radiograph fails to reflect the alignment and advantages of navigation in total knee arthroplasty. J Arthroplasty 2011;26:756-64.

51. McGrory JE, Trousdale RT, Pagnano MW, et al. Preoperative hip to ankle radiographs in total knee arthroplasty. Clin Orthop Relat Res 2002;(404):196-202.

Change of addressWe require 6 to 8 weeks’ notice to ensure uninterrupted service. Please send your current mailing label, new address and the effective date of change to:

CMA Member Service Centre

1870 Alta Vista Dr.Ottawa ON K1G 6R7

tel 888 855-2555 or 613 731-8610 x2307 fax 613 [email protected]

Changement d’adresseIl nous faut de 6 à 8 semaines d’avis afin de vousassurer une livraison ininterrompue. Veuillez faireparvenir votre étiquette d’adresse actuelle, votrenouvelle adresse et la date de la prise d’effet duchangement, à l’attention du

Centre des services aux membres de l’AMC

1870, prom. Alta VistaOttawa ON K1G 6R7

tél 888 855-2555 ou 613 731-8610 x2307 fax 613 [email protected]




Management of the open abdomen using combination therapy with ABRA and ABThera systems

Background: The open abdomen is an increasingly used technique that is applied in a wide variety of clinical situations. The ABThera Open Abdomen Negative Pressure Therapy System is one of the most common and successful temporary closure systems, but it has limited ability to close the fascia in approximately 30% of patients. The abdominal reapproximation anchor system (ABRA) is a dynamic closure system that seems ideal to manage patients who may not achieve primary fascial closure with ABThera alone. We report on the use of the ABRA in conjunction with the ABThera in patients with an open abdomen.

Methods: We retrospectively analyzed patients with an open abdomen managed with the ABThera and ABRA between January 2007 and December 2012 at the Halifax Infirmary, QEII Health Science Centre, Halifax, Nova Scotia.

Results: Sixteen patients had combination therapy using the ABRA and ABThera sys-tems for treatment of the open abdomen. After removing patients who died prior to clo-sure, primary fascial closure was achieved in 12 of 13 patients (92%).

Conclusion: We observed a high rate of primary fascial closure in patients with an open abdomen managed with the ABThera system in conjuction with the ABRA. Applying mechanical traction in addition to the ABThera should be considered in patients predicted to be at high risk for failure to achieve primary fascial closure.

Contexte : La laparotomie, ou « abdomen ouvert », est une technique de plus en plus employée dans une grande diversité de contextes cliniques. Le système ABThera (théra-pie par pression négative pour abdomen ouvert) est l’un des systèmes de fermeture tem-poraire de l’abdomen les plus fréquemment utilisés et efficaces, mais sa capacité de refer-mer le fascia apparaît limitée chez environ 30 % des patients. Le système ABRA est un système de fermeture dynamique qui semble idéal pour la prise en charge des patients qui pourraient ne pas obtenir une fermeture primaire du fascia avec le système ABThera seul. Nous faisons rapport de l’utilisation du système ABRA en conjonction avec le système ABThera chez des patients soumis à une laparotomie.

Méthodes : Nous avons analysé rétrospectivement des patients soumis à une laparoto-mie et pris en charge au moyen des systèmes ABThera et ABRA entre janvier 2007 et décembre 2012 au Halifax Infirmary du Centre des sciences de la santé QEII d’Halifax, en Nouvelle-Écosse.

Résultats : Seize patients ont subi un traitement concomitant par les systèmes ABRA et ABThera pour leur laparotomie. Après exclusion des patients décédés avant l’obtention de la fermeture primaire du fascia, cette dernière a été réussie chez 12 patients sur 13 (92 %).

Conclusion : Nous avons observé un taux élevé de fermeture primaire du fascia chez les patients soumis à une laparotomie et traités au moyen du système ABThera en conjonction avec le système ABRA. L’application d’une traction mécanique en plus du système ABThera est à envisager chez les patients présumés à risque élevé d’échec de la fermeture primaire du fascia.

T he open abdomen is an increasingly used technique that is applied in a wide variety of clinical situations, including treatment and prevention of abdominal compartment syndrome, damage control laparotomy and

severe intra-abdominal sepsis.1 Once the abdominal fascia has been opened, the viscera must be contained by a temporary abdominal closure (TAC). The goals of TAC include protection of the viscera, prevention of adhesions of the

Alfin N. Mukhi, MD Samuel Minor, MD

From Dalhousie University, Halifax, NS


Presented at the Canadian Critical Care Forum, November 2013.

Correspondence to: S. Minor Dalhousie University 1278 Tower Rd. Rm 813 — Victoria Bldg Halifax NS B3H 2Y9 [email protected]

DOI: 10.1503/cjs.026613

manage-minor.indd 314 14-09-16 10:56 AM

RESEARCH


viscera to the abdominal wall, removal of intra-abdominal fluid and prevention of fascial retraction.2 A variety of dif-ferent techniques for TAC have been used in the past, including the Bagota bag, mesh, Wittmann patch and Barker vacuum pack. A systematic review and prospective observational trial have demonstrated that the ABThera Open Abdomen Negative Pressure Therapy System (KCI USA) may be the most effective TAC method.3,4

Although the ABThera system achieves all the goals of TAC, progressive loss of abdominal domain may still occur because of the ABThera’s limited ability to stabilize the fascia in some patients (Fig. 1). The ABThera, when used alone, fails to reapproximate the fascia in about 30% of patients with an open abdomen.2–4 Failure to close the fas-cia primarily results in an increased risk of enteroatmos-pheric fistula, requirement for skin grafting of the visceral mass and a large ventral hernia. Furthermore, early pri-mary closure of the open abdomen has been associated with improved patient survival.5

The use of mechanical traction with sequential suturing and mesh imbrication in conjunction with the ABThera have been shown to significantly increase primary fascial closure rates to approximately 90%.2,6–9 The abdominal re-approximation anchor system (ABRA; Canica Design Inc.) is a dynamic closure system that uses elastomers through the full thickness of the abdominal wall that slowly pull the fascia together under continuous variable tension. It is eas-ier to manage than mesh imbrication or sequential sutur-ing and allows for the abdominal wall to oscillate with patient movement and breathing. Four case series have previously demonstrated the ABRA’s efficacy in achieving fascial closure in the open abdomen.10–13 Although com-bined therapy using the ABThera and the ABRA seems ideal to manage patients who may not achieve primary fas-cial closure with ABThera alone, this has not been previ-ously described.

We report on the use of the ABRA in conjunction of the ABThera in patients with an open abdomen.

Methods

We conducted an insitution review board–approved, single-institution, retrospective analysis of patients with an open

abdomen who were managed with the ABThera and ABRA systems between January 2007 and December 2012. Patients were identified from the Acute Care Surgery Sur-gical Log, which recorded all emergency surgical cases per-formed at the Halifax Infirmary, QEII Health Science Cen-tre, Halifax, Nova Scotia, Canada. During this time period there was no protocol for the management of the open abdomen. The decision to use the open abdomen was at the discretion of the attending surgeon, as was the use and tim-ing of the ABThera and ABRA.

The usual practice at our institution was to use an ABThera for TAC during the first operation in which an open abdomen technique was employed. ABThera installa-tion involved placing the fenestrated plastic dressing with the incorporated polyurethane sponge over the viscera, under the fascia, down to the retroperitoneum posteriorly, the dia-phragm superiorly and pelvis inferiorly. This prevented adherence of the viscera to the abdominal wall and allowed for mobilization of the fascia while preventing injury to the viscera. A granufoam sponge was then placed over the plastic sheet and the abdomen was sealed with an adherent plastic sheet to the skin. The ABThera was then placed to –125 mm Hg continuous suction. The ABThera dressing was changed every 3–5 days in the operating room.

The ABRA was added to the ABThera at the surgeon’s discretion. Typically, this was done when significant fascial retraction was observed, or when the fascia was failing to medialize over time. Installation of the ABRA involved placing elastomeres 5 cm from the fascial edge and 90° to the fascia through the skin and full thickness of the abdom-inal wall. The elastomeres were placed as close together as the skin anchor buttons would permit, approximately 3 cm apart. The elastomeres were placed over the ABThera fenestrated sheet and below the sponge (Fig. 2). If the fenes-trated silicone sheet included with the ABRA kit was used, it was placed over the ABThera fenestrated sheet and below the granufoam sponges. An adhesive button tail was placed to the skin anchor buttons to prevent displacement and tilt-ing. The ABRA elastomers were tightened daily to 1.5 times their tension-free length along with manual medialization of the fascia until primary closure was achieved. Primary clos-ure was performed in the operating room when the fascia could be brought together under reasonable tension without causing physiologic compromise due to intra-abdominal hypertension. In some cases, intra-abdominal pressure was measured during closure. Fascial closure was performed using a running 1 polydioxanone suture.

Results

During the study period, 78 patients underwent proced-ures using an open abdomen. Overall mortality was 24% (19 of 78). We identified 16 patients who had combina-tion therapy using the ABRA and ABThera for treatment of the open abdomen (Table 1). The mean age of patients

Fig. 1. Patient with an open abdomen demonstrating progres-sive fascial retraction and loss of abdominal domain during ABThera treatment.


RECHERCHE


Fig. 2. Installation of the ABRA system to the ABThera.

Table 1. Patients with an open abdomen managed with both the ABThera and ABRA

Group; age, yr Sex

L1 to ABRA Treatment

LOS ICU

LOS HOSP Ostomy Anastomosis Diagnosis Outcome SAPS II

Bjorch classification

ACS

49 M 12 11 43 58 N N Pancreatitis Primary closure 47 1A

47 M 7 24 37 41 N Y Pancreatitis Primary closure 41 1B

53 F 7 16 N/A 79 N N Pancreatitis Primary closure 46 1A

66 M 4 N/A 16 16 N N Ruptured AAA Death from sepsis

58 1B

36 F 12 31 41 95 N Y Post gastric sleeve

Primary closure 63 1B

40 M 0 5 12 27 N N Post midgut volvulus

Primary closure 51 1A

Trauma

32 M 2 28 28 46 N Y Damage control Primary closure (Died)

48 1B

52 F 2 3 6 40 N Y Damage control Primary closure 30 1B

58 M 7 24 31 40 Y Y Damage control Closure with vicryl mesh

39 1B

33 M 4 17 5 27 Y Y Damage control Primary closure 35 1B

GI

62 M 3 4 29 46 Y N Intraabdominal sepsis


54 M 19 6 29 122 Y Y Intraabdominal sepsis


56 M 4 28 32 146 N Y Intraabdominal sepsis


38 F 15 3 15 28 N N Intraabdominal sepsis

Primary closure 97 1A

65 F 7 N/A 31 31 Y N Intraabdominal sepsis

Death from sepsis

50 1B

66 F 11 N/A 36 36 Y Y Intraabdominal sepsis

Death from sepsis

58 1A

AAA = abdominal aortic aneurysm; ACS = abdominal compartment syndrome; F = female; GI = gastrointestinal; HOSP = hospital; ICU = intensive care unit; LOS = length of stay; M = male; N = no; N/A = not applicable; SAPS II = Simplified Acute Physiology Score; Y = yes.


RESEARCH


was 52.5 (range 33–66) years, and 10 patients (63%) were men. In patients managed without an ABRA, mortality was 26% (16 of 62), and primary closure failed in 13 of the remaining 46 patients (28%). Of those in whom primary closure failed, 8 were bridged with mesh and 5 were man-aged with a planned ventral hernia.

In patients managed with an ABRA and ABThera, the most common reason for using an open abdomen was for the management of abdominal compartment syndrome (38%) and severe intra-abdominal sepsis (38%). Severe pancreatitis accounted for the majority of abdominal com-partment syndrome cases. Damage control surgery, in the setting of trauma, accounted for 25% of cases.

An anastomosis was present in 9 of 16 (56%) and an ostomy (i.e., colostomy, ileostomy, diverting ileostomy/colostomy) was present in 6 (38%) patients. Four (25%) patients had both an anastomosis and an ostomy. There were no reported stoma complications related to the addi-tion of the ABRA. None of the patients had a history of radiation treatment.

After the ABThera was installed, the addition of the ABRA system occurred at a median of 7 (range 0–19) days. Most patients had the ABRA system applied on the first or second ABThera dressing change. There was significant variability observed in the timing of ABRA installation, as it was at the discretion of the surgeon. The patient who had the ABRA placed on day 0 had a decompressive lapa-rotomy for abdominal compartment syndrome. In this case, the elastomers were placed but not loaded under ten-sion in an attempt to prevent fascial retraction in excess of what was required to relieve intra-abdominal hypertension.

All patients in whom the ABRA was used had a Bjorch Open Abdomen Classification System grade of 1A or 1B.14

After removing patients who died prior to closure, pri-mary fascial closure was achieved in 12 of 13 patients (92%). The number of days required for fascial closure after the addition of the ABRA was a median of 17 (range 3–31) days. Fascial closure was not achieved in the remain-ing patient because the surgeon elected to remove the ABRA and bridge the fascial gap with a Vicryl mesh after 31 days with an open abdomen and 24 days of treatment with the ABRA and ABThera.

Skin breakdown at the ABRA button site was observed in 1 (6%) patient. Recurrent abdominal compartment syn-drome was noted in 1 patient who was subsequently treated in the intensive care unit by decreasing the tension of the ABRA elastomers.

Overall survival in patients with an ABRA and ABThera was 75%, with 3 of the 4 deaths occurring before primary fascial closure was achieved. Sepsis and multisystem organ failure was the cause of death in all cases, including 1 patient who died from an anastamotic leak and ensuing sepsis after primary closure. The average Simplified Acute Physiology II Score (SAPS II) was 54 (range 41–97). The length of stay in the intensive care unit was a median of 30

(range 5–47) days. Excluding the 4 patients who died, the length of stay in hospital was a median of 43.5 (range 27–146) days.

Discussion

The use of the open abdomen, although a lifesaving tech-nique, presents a clinical challenge that is associated with significant morbidity and mortality. Once the physiologic crisis necessitating the open abdomen has resolved, rapid primary closure of the fascia is required to prevent com-plications, such as fistula and loss of fluid, protein, heat and electrolytes. Failure to close the fascia results in a giant ventral hernia that requires a complex repair and has significant associated morbidity.4 Furthermore, delay in closure of the fascia is associated with increased mortality.

The ABThera open abdomen negative pressure therapy protects the viscera from adhering to the abdominal wall and effectively removes fluid from the entire abdominal cav-ity. This facilitates the safe mobilization of the native fascia and, compared with other types of TAC, improves the rate of primary fascial closure.3,15,16 However, the ABThera still fails to achieve primary closure in approximately 30% of patients with an open abdomen. In our experience as well as other authors’, it is usually apparent 4–7 days after place-ment of the ABThera that the fascia retracts further and will likely not close with the ABThera alone.10,17 Although the reason for using an ABRA in addition to the ABThera was not recorded in our series, surgeons typically choose to use the ABRA in patients in whom they feel the fascia is unlikely to close with the ABThera alone. Consequently, we hypoth-esize that if the ABThera had been used without the ABRA, a primary fascial closure rate of less than 70% would have been observed in these patients. In spite of this, the addition of the ABRA to the ABThera was associated with a success-ful primary fascial closure in 92% of patients in our study. In the 1 patient in whom primary fascial closure failed, the sur-geon removed the ABRA and placed a vicryl mesh after 24 days of treatment with the ABRA. It is possible that pri-mary fascial closure may have been possible in this patient as well if more time had been given with the ABRA, as success-ful closure has been reported at up to 31 days in our study and 62 days in other studies involving the ABRA.10–12 Achieving primary fascial closure avoids the morbidity of a ventral hernia and a second operation to repair it. However, the prolonged use of the ABRA to achieve primary closure comes at the cost of ongoing ABThera changes and increased length of stay in hospital. A cost analysis to deter-mine the length of time after which attempting primary clos ure with the ABRA is no longer cost-effective could be a direction for future study.

The high rate of primary fascial closure observed in our series is consistent with that in other studies that have used the addition of mechanical traction to the ABThera sys-tem. Rasilainen and colleagues6 reported a primary fascial


RECHERCHE


closure rate of 53% using the intra-abdominal vacuum-assisted closure (VAC) system alone, which increased to 93% primary closure when a mesh was sequentially imbri-cated over top. Similarly, sequential fascial suturing over the intra-abdominal VAC has increased rates of primary fascial closure to approximately 90%.8,9 Specific to the ABRA system, Verdam and colleagues11 reported primary fascial closure in 14 of 16 patients (88%), Salman and col-leagues10 reported primary closure in 7 of 7 patients with an open abdomen, and Haddock and colleagues13 reported primary closure in 30 of 36 (83%) patients.

We speculate that early application of the ABRA may be important in achieving successful primary fascial clos-ure. Early application prevents fascial retraction and can start pulling the fascia together while the tissues are rela-tively more dynamic. Preventing adhesions of the viscera to the abdominal wall is also important to allow for safe and unimpeded medialization of the fascia. This is high-lighted in the study by Reimer and colleagues12 in which the ABRA was placed relatively later (average of 18 d) and in which primary closure was achieved in only 14 of 23 pa tients (61%). Success of primary fascial closure was associated with earlier application of the ABRA and having the fascia free of adhesions to the abdominal wall.12 Similar to us, Haddock and colleagues13 reported fascial closure in 83% of patients with an average time from first laparotomy to ABRA placement of 11.9 days. However, in their study, there appeared to be a longer median time from the first laparotomy to the placement of the ABRA in patients achieving primary fascial closure. They hypothesized that patients who had a more thorough decontamination of the abdomen with a longer duration of an open abdomen would be more amenable to closure.13 In our cohort, the ABRA was placed earlier in the trauma subgroup of patients relative to the gastrointestinal sepsis subgroup, highlighting the desire to create as clean an abdominal cav-ity as possible before placing the ABRA.

In previous studies, trauma patients had a higher rate of primary closure than those with septic abdomens.17,18 In our series, we observed an equally high rate of closure in patients with nontraumatic etiologies, possibly because we used the ABThera system, which allowed for suctioning of the pelvis, paracolic gutters and subdiaphragmatic spaces. The previous studies used a VAC system, which may not have been able to decontaminate the abdomen as readily and thereby prevented successful primary closure.

Our study demonstrates the severity of illness associated with patients managed with an open abdomen. The observed mortality of 25% is consistent with that of other cohorts of patients managed with an open abdomen.2,17,19 No deaths in our study were directly attributable to the ABRA device. Pressure sores related to the ABRA buttons have been reported as a complication of the ABRA, with the study by Verdam and colleagues11 reporting its occur-rence in 12 of 18 patients. In our study, skin breakdown

was observed in only 1 patient. The reason for this may be secondary to our practice of placing the ABRA buttons over the ABThera adherent dressing, which may have pro-vided additional protection to the skin.

Limitations

This study has several weaknesses. First, it is uncontrolled and describes outcomes of a cohort of patients managed entirely at the surgeon’s discretion, with no protocol to guide therapy. The reasons the surgeon decided to add the ABRA were not specifically recorded for all patients. Second, as the study was not prospective, many pertinent data points, such as body mass index, were not available for all patients. This makes the generalization of our observations difficult.

Based on the experience gained from this cohort, and in context of other studies using the ABThera, we have pro-posed a treatment algorithm of the open abdomen that rec-ommends early use of mechanical traction in addition to the ABThera (Fig. 3). This recommendation has been made by other authors as well.2 The ABThera is essential for remov-ing fluid and contamination from the abdomen and prevents adhesions between the visceral mass and the abdominal wall. If the fascia is failing to medialize by the first dressing change on day 3–5, we suggest the addition of mechanical traction to the fascia in order to increase the rate of primary fascial clos-ure. The options for this include sequential suturing of the

Fig. 3. Proposal for management of the open abdomen.

Patient requiring decompressive laparotomy

Apply ABThera system

First ABThera change

Routine ABThera changes and ABRA

tightening

Apply ABThera system

Apply ABThera/ABRA systems

Fascial closure

Intraoperative evaluation

If closure not possible

If closure possible within next 4 days

Adjuncts required if primary closure not possible


RESEARCH


fascia, progressive imbrication of mesh sutured to the fascia and the ABRA system. We prefer the ABRA system, as in our experience it takes less time to manage than mesh imbrication or sequential suturing, and tightening can be done daily at the bedside without disrupting the ABThera. Although not spe-cifically recorded, a typical time to install the ABRA is about 10 minutes. The ABRA does not impede the changing of the ABThera, as the elastomers are easily loosened and retracted. The only extra time added to the ABThera change is the time required to tighten the elastomers, which typically takes less than 5 minutes. The ABRA system also leaves the edges of the native fascia undisturbed, which is an attractive advantage at the time of definitive closure.

ConClusion

We observed a high rate of primary fascial closure in patients with an open abdomen managed with the ABThera in conjuction with the ABRA. Consideration should be ginen to applying mechanical traction in addition to the ABThera in patients predicted to be at high risk for failure to achieve primary fascial closure.Competing interests: S. Minor has received an honorarium from KCI to provide an educational talk on temporary abdominal closure. This occurred 3 times over the past 3 years. Each honorarium was approxi-mately $1000. The talk was not specific to the ABThera product, but it did discuss its use. None declared for A. Mukhi.

Contributors: Both authors designed the study, acquired and analyzed the data, wrote and reviewed the article, and approved the final version for publication.

References

1. Navsaria P, Nicol A, Hudson D, et al. Negative pressure wound ther-apy management of the “open abdomen” following trauma: a pro-spective study and systematic review. World J Emerg Surg 2013;8:4.

2. Regner JL, Kobayashi L, Coimbra R. Surgical strategies for man-agement of the abdomen. World J Surg 2012;36:497-510.

3. Roberts DJ, Zygun DA, Grendar J, et al. Negative-pressure wound therapy for critically ill adults with open abdominal wounds: a sys-tematic review. J Trauma Acute Care Surg 2012;73:629-39.

4. Cheatham ML, Demetrios D, Fabian TC, et al. Prospective study examining clinical outcomes. World J Surg 2013;37:2018-30.

5. Cheatham ML, Safcsak K. Is the evolving management of intra-abdominal hypertension and abdominal compartment syndrome improving survival? Crit Care Med 2010;38:402-7.

6. Rasilainen SK, Mentula PJ, Leppaniemi AK. Vacuum and mesh-mediated fascial traction for primary closure of the open abdomen in critically ill surgical patients. Br J Surg 2012;99:1725-32.

7. Cothren CC, Moore EE, Johnson JL, et al. One hundred percent fascial approximation with sequential abdominal closure of the open abdomen. Am J Surg 2006;192:238-42.

8. Suliburk JW, Ware DN, Balogh Z, et al. Vacuum-assisted wound closure achieves early fascial closure of open abdomens after severe trauma. J Trauma 2003;55:1155-60.

9. Miller PR, Meredith JW, Johnson JC, et al. Prospective evaluation of vacuum-assisted fascial closure after open abdomen: planned ven-tral hernia rate is substantially reduced. Ann Surg 2004;239:608-14.

10. Salman AE, Yetisir F, Aksoy M, et al. Use of dynamic closure sys-tem in conjunction with vacuum-assisted closure therapy in delayed closure of open abdomen. Hernia 2014;18:99-104.

11. Verdam FJ, Dolmans DE, Loos MJ, et al. Delayed primary closure of the septic abdomen with a dynamic closure system. World J Surg 2011;35:2348-55.

12. Reimer MW, Yelle YD, Reitsma B, et al. Management of open abdominal wounds using a dynamic fascial closure system. Can J Surg 2008;51:209-14.

13. Haddock C, Konkin DE, Blair NP. Management of the open abdo-men with the Abdominal Reapproximation Anchor dynamic fascial closure system. Am J Surg 2013;205:528-33.

14. Björck M, Bruhin A, Cheatham M, et al. Classification, an impor-tant step to improve the management of patients with an open abdomen. World J Surg 2009;33:1154-7.

15. Frazee RC, Abernathy SW, Jupiter DC, et al. Are commercial neg-ative pressure systems worth the cost in the open abdomen man-agement? J Am Coll Surg 2013;216:730-3.

16. Boele van Hensbroek P, Wind J, Dijkgraaf MG, et al. Temporary closure of the open abdomen: a systematic review on delayed pri-mary fascial closure in patients with an open abdomen. World J Surg 2009;33:199-207.

17. Goussous N, Kim BD, Jenkins DH, et al. Factors affecting primary fascial closure of the open abdomen in the non-trauma patient. Surgery 2012;152:777-83.

18. Mentula P. Non-traumatic causes and the management of the open abdomen. Minerva Chir 2011;66:153-63.

19. de Costa A. Making a virtue of necessity: managing the open abdomen. ANZ J Surg 2006;76:356-63.




Surgical management of symptomatic hydatid liver disease: experience from a Western centre

Background: Hydatid liver cysts are rare in North America. The objective of this study was to determine the optimal surgical management for hydatid liver cysts treated outside endemic areas.

Methods: We reviewed the cases of consecutive patients who underwent manage-ment of hydatid liver cysts. Radical liver resections were compared with other types of procedures. Clinical presentation, investigations, perioperative outcomes and long-term follow-up were evaluated. We evaluated disease recurrence using the Kaplan–Meier method.

Results: Forty patients underwent surgery for hydatid liver cysts. Most patients had single (68%) right-sided (46%) cysts with a median size of 10 cm. Most (83%) under-went liver resection with or without drainage/marsupialization. Radical liver resection was carried out in 60% (19 major, 5 minor). Additional procedures were required in 50% (biliary fistulization 30%, diaphragmatic fistulization 20% or paracaval location/fusion 8%). Postoperative complications occurred in 48%. The median follow-up was 39 months. The 3-year recurrence-free survival was significantly different between patients who had radical resection and those who had other procedures (100% v. 71%, p = 0.002).

Conclusion: The surgical management of hydatid liver cysts in North America remains rare and challenging and is frequently associated with fistulizing complica-tions. Excellent long-term outcomes are best achieved using principles of radical liver resection that are familiar to North American surgeons.

Contexte : L’hydatidose (kyste hydatique du foie) est une affection rare en Amérique du Nord. Cette étude visait à déterminer quelle était la meilleure façon de prendre en charge cette maladie à l’extérieur de zones où elle est endémique.

Méthodes : On a revu les cas de patients consécutifs traités pour des kystes hyda-tiques du foie. L’ablation radicale du foie a été comparée à d’autres types d’intervention. Le tableau clinique, les examens exploratoires, les résultats périopéra-toires et le suivi de longue durée ont été évalués. On a aussi évalué la récurrence de la maladie en utilisant la méthode Kaplan–Meier.

Résultats : Quarante patients avaient été opérés pour des kystes hydatiques du foie. La plupart présentaient des kystes simples (68 %) dans le foie droit (46 %), qui mes-uraient en moyenne 10 cm de diamètre. La plupart (83 %) avaient subi une résection hépatique avec ou sans drainage ou marsupialisation. Une résection radicale a été pra-tiquée chez 60 % des patients (19 cas majeurs, 5 cas mineurs). D’autres interventions se sont avérées nécessaires dans 50 % des cas (fistulisation dans les voies biliaires 30 %, fistulisation dans le diaphragme 20 %, localisation paracave ou fusion 8 %). Des complications postopératoires sont survenues dans 48 % des cas. La durée moyenne du suivi a été de 39 mois. On a observé une différence significative entre le taux de survie sans récidive sur 3 ans entre les patients ayant subi une résection radicale et ceux ayant subi une autre intervention (100 % c. 71 %, p = 0.002).

Conclusion : En Amérique du Nord, le traitement chirurgical de l’hydatidose reste rare, difficile et souvent compliqué par une fistulisation. La résection hépatique radi-cale, que les chirurgiens nord-américains maîtrisent bien, est l’intervention permet-tant d’obtenir les meilleurs résultats à long terme.

Guillaume Martel, MD Salima Ismail, MD André Bégin, MD Franck Vandenbroucke-Menu, MD Réal Lapointe, MD

From the HPB Surgery and Liver Transplant Unit, Hôpital Saint-Luc, Centre Hospitalier de l’Université de Montréal, Montréal, Que.

Presented in part at the 9th World Congress of the International Hepato-Pancreato-Biliary Association, Apr. 20, 2010, Buenos Aires, Argentina, and the Canadian Surgery Forum, Sept. 3-4, 2010, Québec, Que.


Correspondence to: R. Lapointe HPB Surgery and Liver Transplant Unit Hôpital Saint-Luc, Centre Hospitalier de l’Université de Montréal 1058 Saint-Denis, Rm 6303B Montréal QC H2X 3J4 [email protected]

DOI: 10.1503/cjs.024613

surg-lapointe.indd 320 14-09-16 10:54 AM

RESEARCH


H ydatid disease is an important parasitic ailment that affects primarily the liver in 75% of cases.1 Most cases in humans are caused by Echinococcus granulosus

or Echinococcus multilocularis, which account for cystic and alveolar echinococcosis, respectively.1 The worldwide annual incidence of cystic echinococcosis is 1–200 per 100 000.1 Dogs and other canids are the definitive hosts for the adult tapeworm, whereas ungulates (typically sheep) act as inter-mediate hosts by ingesting shed eggs.1,2 Humans living in proximity to definitive and intermediate hosts can become accidental intermediate hosts by the same mech an ism. Hyda-tid disease is endemic in many sheep- and cattle-raising parts of the world, namely Mediterranean countries, the Middle East, Eastern Europe and South America.

The management of hydatid cysts of the liver is contro-versial. Therapeutic options can be broadly divided into 3 categories: medical treatment, conservative surgery and radical surgery. Medical therapy, using the antihelminthic agents albendazole or mebendazole, has been recom-mended for asymptomatic and uncomplicated cysts smaller than 5 cm.2 Conservative surgical options include external drainage and unroofing procedures in addition to various types of residual cavity management strategies. Radical surgical options include formal liver resection and com-plete pericystectomy.

The surgical management of hydatid liver cysts is most common in endemic regions of the world. Not surprisingly, surgeons in these areas have accumulated extensive experi-ence and reported large series of patients, documenting recurrence rates of 7.7%–30% and morbidity of 21%–80% with conservative surgical therapies.3–6 In contrast, liver sur-geons working in Western centres — particularly North American hospitals — can be expected to treat only a hand-ful of such patients over the course of their careers.7–11 In this context, it becomes particularly important to define surgical treatment strategies that are specific to the exper-tise of Western liver surgeons, which is lacking in the liter-ature. We sought to review a single North American ter-tiary care centre’s experience with patients who underwent liver surgery for hydatid cysts of the liver.

Methods

This work was a retrospective review of our institutional experience with hydatid disease of the liver. All consecutive patients who underwent inpatient management or day pro-cedures for hydatid liver cysts at our provincial referral hep-atobiliary academic unit were included (1988–2012). The Centre Hospitalier de l’Université de Montréal Research Center Ethics Committee approved our study protocol.

In order to identify study patients, we searched dis-charge abstracts for diagnoses of hydatid disease based on the International Classification of Diseases (ICD)-10 (codes 122.8, 122.9) and ICD-9 (codes B67.8, B67.9). All other patients treated with albendazole were identified

through the pharmacy database, as this drug is not approved for routine use in Canada and is thus dispensed on an individual patient basis after approval by Health Canada. Individual surgeon records were also mined for any missing cases. Cases of hydatid liver cysts were defined on the basis of characteristic imaging findings, ecchinococ-cal serology, microscopic identification of scolices within cyst fluid and pathological examination of resected speci-mens. We retrieved the medical records of potential study patients and checked them manually for inclusion. Rele-vant data pertaining to each study patient were extracted from the medical records and entered into a computerized data set. Data points of interest included patient demo-graphics, preoperative features (serology, imaging, medical therapy), operative features (type of surgery, precautions specific to hydatid disease, cholangiography, complica-tions, blood loss, duration) and postoperative features (length of stay, complications, pathology, recurrence, serology). No imaging classification of hydatid liver cysts was used at our centre during the study period, as such cysts are too infrequent in North America.

Indications for surgical treatment were based on World Health Organization recommendations.12 Briefly, surgery was indicated for large liver cysts; symptomatic cysts; cysts at risk of rupture; infected cysts; and cysts demonstrating or at risk for fistulization into the biliary tree, diaphragm/pleural cavity or other vital organs. Completely calcified cysts were not routinely treated. In general, complete sur-gical resection was the preferred treatment option at our institution. Pericystectomy was not performed owing to our lack of experience with this procedure. Combinations of resection and marsupialization/drainage were used when the entire burden of hepatic cysts could not be safely resected owing to anatomic location or concerns regarding the volume of the future liver remnant. Associ-ated surgical procedures were performed based on the anatomic location of individual cysts and evidence of fis-tulizing disease on preoperative imaging. Diaphragmatic resection and primary repair was carried out whenever the cyst appeared to have invaded or be adherent to the diaphragm. Percutaneous puncture-aspiration-injection-reinjection (PAIR) was not performed at our institution except in patients who were deemed not to be surgical candidates.

Based on the Brisbane 2000 terminology,13 formal liver resection was defined as the complete surgical excision of all hydatid cysts within the liver. In practice, this approach involved resective principles similar to those used in onco-logic liver surgery, with resection of the entire cyst, includ-ing at a minimum its laminated membrane and typically including the pericyst into healthy parenchyma to achieve a negative resection margin. When the cyst was initially too bulky to allow for safe liver resection, the cyst was incised and drained using a large-bore gynecologic suction aspirator. The cyst cavity was then filled with hypertonic


RECHERCHE


saline and allowed to sit undisturbed for 10–15 minutes. In all cases, we took precautions, including isolating the liver with laparotomy pads soaked in hypertonic saline and suturing a plastic sterile drape to the apex of any cyst before suction aspiration, to avoid intra-abdominal spillage of cyst contents. Marsupialization involved the drainage of the cyst contents, unroofing of the cyst wall as much as possible and oversewing of the remaining wall circumfer-ence to avoid its reaccumulation. Operative drainage con-sisted of evacuation of the cyst contents in a manner analo-gous to PAIR.

Preoperative or postoperative antiparasitic agents were routinely administered after consultation with an infectious diseases specialist. All postoperative compli-cations were recorded and graded according to the Clavien–Dindo classification.14 Follow-up after surgery was at the surgeon’s discretion and was typically car-ried out in conjunction with the infectious diseases consultant. Disease recurrence was defined on the basis of evidence of 1 or more novel hydatid cyst on high-quality imaging, as interpreted by experienced abdom-inal radiologists.


We compared patients treated between 2003 and 2012 with those treated between 1988 and 2002. We generated summary statistics as proportions for categorical variables and as medians with interquartile ranges for continuous variables. Cyst recurrence was examined using the Kaplan–Meier and actuarial life tables methods, using the time from definitive surgery to recurrence in months. Dichotomous outcomes were compared using the Fisher exact test, and time-to-event data were compared using the log-rank test. All statistical analyses were performed using SAS software version 9.2 (SAS Institute Inc.).

Results

Forty patients with hydatid liver cysts underwent surgery, 20 of which took place in the last 10 years (Table 1). Most patients were men and were of Mediterranean, Middle-Eastern and Canadian origin. Most patients presented with nondifferentiated abdominal pain and underwent a com-bination of ultrasonography and computed tomography of

Table 1. Demographic and clinical characteristics of study participants

Group; no. (%)*

CharacteristicWhole cohort,

n = 401988–2002,

n = 202003–2012,

n = 20

Sex, male/female 24 (60)/16 (40) 10 (50)/10 (50) 14 (70)/6 (30)

Age, median (IQR) yr 40.5 (32.5–55.5) 43 (31–57.5) 39.5 (33.5–50.5)

Country of birth†

Canada‡ 9 (23) 4 (20) 5 (25)

Algeria 9 (23) 3 (15) 6 (30)

Lebanon 5 (13) 2 (10) 3 (15)

Morocco 4 (10) 3 (15) 1 (5)

Italy 3 (8) 3 (15) 0

Bulgaria 2 (5) 0 2 (10)

Greece 2 (5) 2 (10) 0

Other§ 5 (13) 3 (15) 2 (10)

Presenting symptoms/signs

Abdominal pain 28 (70) 14 (70) 14 (70)

No symptoms/incidental 11 (28) 5 (25) 6 (30)

Nausea/vomiting 6 (15) 3 (15) 3 (15)

Palpable mass 3 (8) 2 (10) 1 (5)

Jaundice and/or fever 3 (8) 1 (5) 2 (10)

Echinoccocal serology†

Positive 25 (68) 12 (60) 13 (76)

Negative 12 (32) 8 (40) 4 (24)

Imaging modalities

Ultrasonography 35 (88) 19 (95) 16 (80)

CT, abdomen 38 (95) 20 (100) 18 (90)

CT, chest 6 (15) 3 (15) 3 (15)

MRI 20 (50) 7 (35) 13 (65)¶

CT = computed tomography; IQR = interquartile range; MRI = magnetic resonance imaging. *Unless otherwise indicated. †Data missing for some patients. ‡Four of the 9 Canadian patients were from the First Nations. §Afghanistan, Armenia, Romania, Spain, Turkey, each with n = 1. ¶p = 0.06.


RESEARCH


the abdomen to make the diagnosis of hydatid liver cyst. Preoperative ecchinococcal serology was available for 37 patients and was positive in 68%.

The characteristics of all hydatid cysts are presented in Table 2. The majority of patients had a single hydatid cyst, whereas 10% had 4 or more concomitant cysts. Bilobar disease was found in 11 (28%) patients, 73% of whom had 2 or more cysts.

In total, 95% of patients underwent medical therapy: 67% (n = 26) in the preoperative phase, 87% (n = 34) in the postoperative phase and 60% (n = 24) in both the pre- and postoperative phases. All but 1 patient were treated

with albendazole (1 patient was treated with mebendazole). The 3 patients who did not receive medical therapy were treated before 1992.

All patients included in this series underwent surgical therapy (Table 3); 33 (83%) patients underwent liver resection with or without marsupialization/drainage. Con-servative therapy (drainage or marsupialization) was car-ried out as the sole procedure in 7 (18%) patients. Radical liver resection was the sole form of surgical therapy in 60% of patients. Of the 24 patients who underwent radical liver resections, 19 had major and 5 had minor hepatectomies. The 9 patients who underwent combination liver resection

Table 2. Hydatid cyst features

Group; no. (%)*

Cyst featuresWhole cohort

n = 401988–2002

n = 202003–2012

n = 20

Liver location†

Right hemiliver 18 (46) 10 (50) 8 (40)

Left hemiliver 10 (26) 5 (25) 5 (5)

Bilobar 11 (28) 5 (25) 6 (30)

Number of cysts

1 27 (68) 14 (70) 13 (65)

2 6 (15) 2 (10) 4 (20)

3 3 (8) 3 (15) 0

≥ 4 4 (10) 1 (5) 3 (15)

Maximal cyst diameter‡

All cysts, median (IQR), cm 7.9 (5–12) 7 (5–10.1) 8.9 (5.3–12.1)

Per patient, median (IQR), cm 9.9 (6–13) 10 (6–13.5) 11 (7.6–12.8)

IQR = interquartile range. *Unless otherwise indicated. †Data missing for some patients. ‡Fifty-three cysts in 37 patients.

Table 3. Medical and surgical therapies of hydatid liver cysts

Group; no. (%)

Surgical therapyWhole cohort

n = 401988–2002

n = 202003–2012

n = 20

Main procedures

Radical liver resection 24 (60) 13 (65) 11 (55)

Liver resection + marsupialization 6 (15) 1 (5) 5 (25)

Marsupialization 4 (10) 1 (5) 3 (15)

Liver resection + drainage 3 (8) 3 (15) 0

Drainage 3 (8) 2 (10) 1 (5)

Associated procedures

Intraoperative ultrasonography 20 (50) 5 (25) 15 (75)†

Diaphragmatic resection/repair 8 (20) 3 (15) 5 (25)

Cholangiography 7 (18) 7 (35) 0†

Closure of cyst-biliary fistula 3 (8) 3 (15) 0

CBD exploration 3 (8) 3 (15) 0

IVC resection/repair 2 (5) 2 (10) 0

Right adrenalectomy 2 (5) 2 (10) 0

Intra-abdominal abscess drainage 2 (5) 0 2 (2)

Other* 7 (3% each) 3 (15) 4 (20)

CBD = common bile duct; ERCP = endoscopic retrograde cholangiopancreatography; IVC = inferior vena cava. *Gastric lesser curve resection, pericardial resection, sphincteroplasty, thoracotomy, ERCP, pelvic hydatid cysts excision, bilateral lung hydatid cysts excision (wedges at second operation 2 months later). †p < 0.05.


RECHERCHE


and marsupialization/drainage had an additional 3 major and 6 minor liver resections. All but 1 patient who under-went resection and marsupialization had bilobar disease. Hypertonic saline was administered in 32 (80%) patients.

In 20 (50%) patients, an additional 34 procedures (excluding intraoperative ultrasonography) were performed during the same anesthetic (Table 3). These pro ced ures were uniformly associated with anatomic or technical chal-lenges associated with individual cysts, including fusion with the diaphragm (n = 8, 20%), paracaval/posterior loca-tion (n = 3, 8%) and concern over possible biliary fistuliza-tion (n = 12, 30%). The median duration of surgery was 295 (IQR 245–375, range 165–515) minutes. Intraoperative complications occurred in 7 (18%) patients; complications included hemorrhage (n = 2), minimal leakage of cyst con-tents controlled with hypertonic saline-soaked sponges (n = 3), hypotension suspected of being related to anaphylaxis (n = 2) and anesthesia-induced hypotension (n = 1). There was no difference in duration of surgery (p = 0.69) or opera-tive complications (p = 0.63) between the study periods.

The median length of stay in hospital was 9.5 (IQR 6–16.5, range 4–93) days. Postoperative stay was 15 (IQR 10–22) days in 1988–2002 and 7 (IQR 6–8.5) days in 2003–2012 (p = 0.023). A total of 29 postoperative complications were identified among 19 (48%) patients. Based on the Clavien–Dindo classification, all postoperative complica-tions were at most grade 3a in severity (Table 4). Of the complications directly related to the liver surgery, wound infection was the most common, followed by bile leakage. One patient underwent percutaneous drainage of an infected liver bed collection that was attributable to a bile leak (grade 3a) and also experienced delirium following right hepatectomy (grade 1). Four other patients had bile leaks identified within closed suction drains. Of these, 1 patient was managed conservatively (grade 1), 1 required the addi-tion of antibiotics (grade 2) and 2 required endoscopic retro-grade cholangiopancreatography for definitive control (grade 3a). Finally, 1 patient required percutaneous drainage of a residual liver abscess (grade 3a) and another had a delayed percutaneous drainage of a large pleural effusion at 3 weeks (grade 3a). There was no significant difference in overall postoperative complications between radical and other liver procedures (54% v. 38%, p = 0.30). There was no significant difference in overall postoperative complication rates between study periods (50% v. 45%, p = 0.75) except for postoperative bile leakage (25% v. 0%, p = 0.047).

The preoperative diagnosis of hydatid liver cysts was confirmed at pathology and microscopic examination of cyst contents in all patients. The median follow-up after surgery was 39 (IQR 10–105, range 0.2–234) months. The Kaplan–Meier curve for recurrence-free survival is presented in Figure 1, comparing radical resection and other procedures (log-rank test p = 0.002). The 3-year recurrence-free survival was 89% for the whole cohort, 100% for radical resection and 71% for other procedure

types. Four (10%) patients experienced hydatid cyst recur-rence at 4, 12, 24 and 71 months, respectively, after under-going simple drainage (n = 1), liver resection/drainage (n = 1), and liver resection/marsupialization (n = 2). No case of recurrence occurred in patients who underwent radical resection (25% v. 0%, p = 0.020). There was no significant difference in the crude recurrence rate at maximal follow-up (p = 0.61) or in disease-free recurrence between the study time periods (p = 0.11).

Discussion

This study has addressed the surgical management of hydatid liver cysts in the context of a Western tertiary hepatobiliary referral centre. This work has documented the relative rarity of liver surgery for ecchinococcal disease in North America and has also documented a high pro-portion of complicated cysts. Importantly, we have shown

Fig. 1. Kaplan–Meier curve for recurrence-free survival following hydatid cyst surgery, comparing radical resections (dashed line) and other procedures (solid line), log-rank test p = 0.002.

Sur

viva

l pro

babi

lity

1.0

0.8

0.6

0.4

0.2

0.0 + Censored

0 16 6 4 2 2 1 24 16 14 10 9

0 50 100 150 200 Recurrence-free survival, mo

Radical 0 1

Table 4. Postoperative complications, by Clavien–Dindo classification

Group; no. (%)

Complications Grade 1 Grade 2 Grade 3a Total

Wound infection 6 1 7 (18)

Bile leak 1 1 3 5 (13)

Gastroparesis/ileus 2 2 4 (10)

Pleural effusion 2 1 3 (8)

Clostridium difficile colitis 2 2 (5)

Pneumonia 2 2 (5)

Residual abscess 1 1 (3)

Pulmonary edema 1 1 (3)

Urinary tract infection 1 1 (3)

Vocal cord trauma 1 1 (3)

Delirium 1 1 (3)

Pancreatitis 1 1 (3)

Total, % of complications 11 (38) 11 (38) 7 (24) 29


RESEARCH


that long-term successful management of hydatid liver cysts can be achieved with radical liver surgery, demon-strating an acceptably low level of major postoperative morbidities and a low recurrence rate.

The literature on hydatid liver disease is intensely driven by investigators from Mediterranean centres as a conse-quence of their extensive experience with this pathology.3–6 Over the years, a few contributions from Western centres have appeared, originating mostly in Europe.7,9,10 In con-trast, the North American experience with hydatid disease remains extremely limited owing to the rarity of this pathol-ogy and is restricted to rare series and occasional case reports.8,11 To our knowledge, the present series represents the largest combined surgical experience with hydatid dis-ease of the liver in North America. Although the sample size presented in this work is small in comparison to large series from endemic areas, it is nevertheless highly important, as it portrays the work of trained liver surgeons with a wealth of experience in resective oncologic liver surgery but with lim-ited experience with liver infestations. Moreover, the pres-ent series is unique in that it depicts a province-wide tertiary referral pattern within a city with steady immigration from Mediterranean and North African countries.

Despite the rarity of hydatid liver disease in nonendemic areas as well as the complexity of the procedures performed in this series, an acceptable rate of postoperative morbidity was achieved. Other series of liver surgery for hydatid dis-ease have reported postoperative complication rates of 20%–49%.3,4,7–9,15–17 While the overall complication rate identified in this study (48%) was on the higher end of the previously published range, we argue that this is an accept-able morbidity rate. All recorded complications were classi-fied as Clavien–Dindo grade 3a or less, with 76% of compli-cations classified as grade 1 or 2. All surgical and medical complications were accounted for in our series in contrast to other studies that sometimes included only surgical or cyst cavity–related complications. In our series, the most notable complications were postoperative bile leaks in 5 patients, gastroparesis and/or ileus in 4 patients and wound infections in 7 patients — findings that are likely to be related to the complicated nature of cysts treated in this cohort.

Roughly half the patients included in this series required additional operative procedures related to complicated hydatosis. Additional procedures associated with compli-cated cysts were broadly classified as biliary fistulization (30%), diaphragmatic fistulization (20%) and paracaval fusion (8%). Biliary fistulization is a well-known complica-tion of hydatid disease that is thought to occur in 6.6%–26% of patients.18 The presence of a biliary fistula is in dependently associated with deep abdominal complica-tions following hydatid surgery (odds ratio 2.27, 95% confi-dence interval 1.38–3.72).15 Our results are consistent with those of other series. For instance, Secchi and colleagues16 reported carrying out additional biliary procedures among 146 of 268 (54%) patients with complicated hydatid cysts,

including bile duct exploration (52%), endoscopic therapy (17%) and enterobiliary anastomoses (31%). Kilic and col-leagues19 also reported a direct association between maxi-mal cyst size and the likelihood of biliary–cyst communica-tion, with 7.5 cm being the cutoff with the best predictive value (sensitivity 79%, specificity 73%). Chautems and col-leagues7 further reported that 71% of patients with compli-cated cysts were found at surgery to have a cyst–biliary fis-tula, as defined by the visualization of an open bile duct following removal of a cyst. Furthermore, this group also identified daughter cysts within the common bile duct in 50% of patients, who were treated by choledochotomy, clearance and T-tube placement. Diaphragmatic invasion was reported in 14% of complicated cysts within this same study.7 Findings from the present study, as well as compari-son to the literature, lend further support to the use of radi-cal surgery, particularly formal liver resection, as a primary mode of therapy for complicated hydatid cysts. When this approach is deemed technically feasible and safe by experi-enced liver surgeons, it allows for the resection of both the cystic cavity and any area of fistulization.

This work has documented an excellent recurrence-free survival rate among patients treated with radical surgery as well as among those treated with a combination of surgery and drainage procedures. These data compare favourably with those reported by Tagliacozzo and colleagues,3 who reviewed their experience with the surgical management of 454 patients with hepatic hydatosis. This group compared conservative (drainage, marsupialization, omentoplasty; n = 214) and radical surgery (resection, pericystectomy; n = 240), documenting recurrence rates of 30.4% and 1.2% (p < 0.001), respectively. Radical surgery was also associated with a much lower rate of postoperative morbidity (79.9% v. 16.2%, p < 0.001) and comparable mortality (6.5% v. 9.2%, p = 0.30).3 In another study, Chautems and colleagues7 reported on the surgical management of 35 patients with complicated cysts, achieving complete cyst removal in 69% of patients via hepatectomy (n = 12) or pericystectomy (n = 12). This strategy was comparable to our own, although it relied less heavily on formal hepatectomy, and achieved a 0% recurrence rate at a median of 103 months. More recently, Birnbaum and colleagues9 reported on 97 patients with hydatid disease, 85 of whom underwent radical surgery (52 liver resections). While this group presented data in favour of radical resection, the median follow-up among those undergoing resection was only 1.5 months, thus limit-ing their conclusions on cyst recurrence. In contrast to these studies, other groups3–5,17,20,21 have documented variable but generally higher recurrence rates with conservative surgical procedures (11%–30%), highlighting the superiority of rad-ical surgery in preventing recurrence of liver hydatosis. It should be noted that at least 1 group did not find any differ-ence in recurrence rates between conservative and radical surgery after 10 years in a large cohort of 672 patients who underwent primarily conservative surgery (80%).5


RECHERCHE


Limitations

This study has several limitations. First, it was a retrospec-tive review of medical charts and surgeon records. As with all retrospective series, there is a risk of bias related to the information quality available in medical records as well as its extraction. Second, length of follow-up was unequal, with a small number of patients having follow-up at sec-ondary institutions and being lost early to follow-up. Although it is possible that additional cases of disease recur-rence may have occurred among these patients, we argue that this is unlikely given the specialized nature of therapy for ecchinococcal disease and the likelihood that these patients would have been referred back to our centre had recurrence occurred.

ConClusion

The surgical management of hydatid liver cysts in North America remains rare and challenging. Associated compli-cations of hydatid liver cysts, such as biliary fistulization, diaphragmatic fistulization, or vascular abutment, are rela-tively common and must be anticipated. In the North American context, it is recommended that complicated hydatid cysts of the liver be managed whenever possible using principles of radical liver resection by experienced hepatic surgeons.Funding: G. Martel and the HPB Surgery and Liver Transplantation Unit (Université de Montréal) are supported in part by a clinical and research bursary from Covidien Canada.


Contributors: All authors designed the study and acquired the data, which G. Martel, A. Bégin and R. Lapointe analyzed. G. Martel wrote the article, which all authors reviewed and approved for publication.

References

1. Nunnari G, Pinzone MR, Gruttadauria S, et al. Hepatic echinococ-cosis: clinical and therapeutic aspects. World J Gastroenterol 2012; 18:1448-58.

2. Kayaalp C. Hydatid cyst of the liver. In: Blumgart LH, Belghiti J, Jarnagin WR, et al., editors. Surgery of the liver, biliary tract, and pan-creas. 4th ed. Philadelphia (PA): Saunders; 2006:952-970.

3. Tagliacozzo S, Miccini M, Bonapasta SA, et al. Surgical treatment

of hydatid disease of the liver: 25 years of experience. Am J Surg 2011;201:797-804.

4. Safioleas MC, Misiakos EP, Kouvaraki M, et al. Hydatid disease of the liver: a continuing surgical problem. Arch Surg 2006;141:1101-8.

5. El Malki HO, El Mejdoubi Y, Souadka A, et al. Does primary sur-gical management of liver hydatid cyst influence recurrence? J Gastrointest Surg 2010;14:1121-7.

6. Balik AA, Basoglu M, Celebi F, et al. Surgical treatment of hydatid disease of the liver: review of 304 cases. Arch Surg 1999;134:166-9.

7. Chautems R, Buhler LH, Gold B, et al. Surgical management and long-term outcome of complicated liver hydatid cysts caused by Echinococcus granulosus. Surgery 2005;137:312-6.

8. Langer JC, Rose DB, Keystone JS, et al. Diagnosis and manage-ment of hydatid disease of the liver: a 15-year North American experience. Ann Surg 1984;199:412-7.

9. Birnbaum DJ, Hardwigsen J, Barbier L, et al. Is hepatic resection the best treatment for hydatid cyst? J Gastrointest Surg 2012;16:2086-93.

10. Stoot JH, Jongsma CK, Limantoro I, et al. More than 25 years of surgical treatment of hydatid cysts in a nonendemic area using the “frozen seal” method. World J Surg 2010;34:106-13.

11. Mekeel KL, Hemming AW. Combined resection of the liver and the inferior vena cava for hydatid disease. J Gastrointest Surg 2007;11:1741-3.

12. WHO Informal Working Group on Echinococcosis. Guidelines for treatment of cystic and alveolar echinococcosis in humans. Bull World Health Organ 1996;74:231-42.

13. Strasberg SA, Belghiti J, Clavien PA, et al. The Brisbane 2000 ter-minology of liver anatomy and resections. HPB 2000;2:333-9.

14. Dindo D, Clavien PA. Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg 2004;240:205-13.

15. El Malki HO, El Mejdoubi Y, Souadka A, et al. Predictive factors of deep abdominal complications after operation for hydatid cyst of the liver: 15 years of experience with 672 patients. J Am Coll Surg 2008;206:629-37.

16. Secchi MA, Pettinari R, Mercapide C, et al. Surgical management of liver hydatosis: a multicentre series of 1412 patients. Liver Int 2010;30:85-93.

17. Yorganci K, Sayek I. Surgical treatment of hydatid cysts of the liver in the era of percutaneous treatment. Am J Surg 2002;184:63-9.

18. El Malki HO, El Mejdoubi Y, Souadka A, et al. Predictive model of biliocystic communication in liver hydatid cysts using classification and regression tree analysis. BMC Surg 2010;10:16.

19. Kilic M, Yoldas O, Koc M, et al. Can biliary-cyst communication be predicted before surgery for hepatic hydatid disease: Does size matter? Am J Surg 2008;196:732-5.

20. Magistrelli P, Masetti R, Coppola R, et al. Surgical treatment of hydatid disease of the liver: a 20-year experience. Arch Surg 1991; 126:518-23.

21. Akbulut S, Senol A, Sezgin A, et al. Radical vs conservative surgery for hydatid liver cysts: experience from single center. World J Gastroenterol 2010;16:953-9.




Comparison of stable and unstable pertrochanteric femur fractures managed with 2- and 4-hole side plates

Background: Sliding hip screw (SHS) fixation traditionally involves the use of 4-hole side plates; however, 4-hole plates have disadvantages, including longer surgery and greater postoperative pain, and there is little evidence that they provide increased stability. We compared 2- and 4-hole side plates in stable and unstable pertrochanteric fractures.

Methods: We prospectively enrolled consecutive patients with pertrochanteric fem-oral fractures treated between Jan. 1, 2004, and Apr. 30, 2009, with a 135° SHS using either a 2- or 4-hole side plate, based on surgeon preference.

Results: A total of 327 patients were managed with an SHS device (252 women, 75 men). There were 208 stable fracture patterns (AO/OTA 31 A1, A2.1) and 119 un stable (AO/OTA 31 A2.2, A2.3, A3). We managed 172 patients with 2-hole plates and 155 with 4-hole plates. The average duration of surgery (30.44 v. 51.45 min), blood loss (26.0 v. 31.3 g/L) and transfusion requirements (43% v. 31. 60% transfusion) were significantly lower with the 2-hole than the 4-hole plate. There was no significant difference in length of stay (19 v. 16 d). With stable fractures there was no significant difference in failure rate (6.3% v. 4.9%). In unstable fractures there was a significantly higher rate of failure using 2-hole side plates (24.4% v. 10.8%).

Conclusion: In stable fractures, use of an SHS with a 2-hole side plate results in shorter surgery and less blood loss/transfusion than a 4-hole side plate, with equiva-lent survival. In unstable fractures, there is a greater than 2-fold rate of failure when a 2-hole side plate is used.

Contexte : La vis coulissante pour hanche (SHS) implique habituellement la pose de plaques latérales à 4 perforations; toutefois, ce type de plaque comporte des inconvé-nients, notamment une durée de chirurgie plus longue et des douleurs postopératoires plus persistantes, et il n’a pas été démontré qu’elle confère plus de stabilité. Nous avons comparé les plaques à 2 et à 4 perforations dans des fractures pertrochantéri-ennes stables et instables.

Méthodes : Nous avons inscrit de manière prospective des patients consécutifs ayants de fractures pertrochantériennes du fémur et traités entre le 1er janvier 2004 et le 30 avril 2009 au moyen d’une SHS de 135° et d’une plaque latérale à 2 ou à 4 perforations, selon la préférence du chirurgien.

Résultats : En tout, 327 patients ont été traités de la sorte (252 femmes, 75 hom-mes). Nous comptions 208 fractures stables (AO/OTA 31 A1, A2.1) et 119 fractures instables (AO/OTA 31 A2.2, A2.3, A3). Nous avons traité 172 patients au moyen de plaques à 2 perforations, et 155 au moyen de plaques à 4 perforations. La durée moy-enne de la chirurgie (30,44 c. 51,45 min), les pertes sanguines (26,0 c. 31,3 g/L) et les besoins transfusionnels (43 % c. 31,60 % transfusés) ont été significativement moin-dres avec les plaques à 2 perforations qu’avec les plaques à 4 perforations. On n’a noté aucune différence significative pour ce qui est de la durée du séjour hospitalier (19 c. 16 jours). En ce qui concerne les fractures stables, il n’y a pas eu de différence signifi-cative au plan du taux d’échec thérapeutique (6,3 % c. 4,9 %). En ce qui concerne les fractures instables, on a noté un taux significativement plus élevé d’échecs avec les plaques à 2 perforations (24,4 % c. 10,8 %).

Conclusion : Dans les fractures stables, l’utilisation d’une SHS et d’une plaque laté-rale à 2 perforations permet une chirurgie plus brève et cause moins de pertes san-guines et de transfusions que la plaque à 4 perforations, sans différence au plan de la survie. Dans les fractures instables, on observe un taux 2 fois plus élevé d’échecs lorsqu’on utilise une plaque latérale à 2 perforations.

Robert Peter Baird, BSc (Hons), BMBS* Peter O’Brien, MD† David Cruickshank, MD, BSc†

From the *Royal Adelaide Hospital Department of Orthopaedics and Trauma, Adelaide, Australia, and the †University of British Columbia Department of Orthopaedics, Vancouver, BC


Correspondence to: P. O’Brien 3114–910 West 10th Ave. Vancouver BC V5Z 1M9 Peter.O’[email protected]

DOI: 10.1503/cjs.026113

comp-obrien.indd 327 14-09-16 11:01 AM

RECHERCHE


T he use of a sliding hip screw (SHS) and plate for the management of pertrochanteric femoral fractures introduced by Clawson in 19641 is well established

as the gold standard of treatment. There is general consen-sus in the literature on the need to achieve medial and pos-terior cortical contact with the fracture reduction to improve physiologic distribution of force and on the posi-tioning of the lag screw within the femoral head.2,3 Con-troversy remains, however, on the length of the plate used.

By convention a 4-hole plate has been traditionally used and allows for immediate weight bearing postoperatively. The reported disadvantages of a 4-hole plate, over a shorter side plate, include a longer incision and greater dissection, longer duration of surgery, more blood loss and greater postopera-tive pain.4–8 The evidence, however, of any increased stability conferred from the use of a 4-hole plate has been lacking.

In a biomechanical study conducted by Reich and col-leagues,9 the optimal length of side plate was evaluated; they concluded that no more than 4 screws were necessary. Another cadaveric study was performed using a 3-hole side plate, which was found to provide adequate fixation. In that study, however, the specimens were not physiologic-ally loaded, and the lag screw was prevented from telescop-ing.10 A comparison was performed by McLoughlin and colleagues11 between 2- and 4-hole side plates in cadaveric specimens with unstable 3-part fractures. They found that the 2-hole plate was as biomechanically stable as a 4-hole plate under the conditions tested.

Clinical studies using a 2-hole plate have also been pub-lished, demonstrating satisfactory outcomes and minimal complications.4–8 A study by Laohapoonrungsee and col-leagues12 also found satisfactory results using a 2-hole plate with only 2 of 70 cases of side plate failure in unstable frac-tures. However, more than 80% of the cases resulting in moderate or severe collapse, using the method published by Bendo and colleagues,13 were in patients with an un stable fracture pattern.

Determining an outcome measure for these clinical studies is difficult, as mechanical failure of SHS is rare and these patients represent a group with multiple medical co-morbidities and poor function preinjury. Objectively, how-ever, Steinberg and colleagues14 found an increased rate of failure with more than 15 mm of telescoping of the lag screw. This excessive sliding has also been shown to be associated with greater postoperative pain.15–16

It may be, therefore, that while a 2-hole plate is ade-quate for fixation of stable 2-part fractures, there may be an increased rate of failure with its use in patients with unstable fracture patterns.

The present study is a review of prospectively collected data for both stable and unstable pertrochanteric fractures treated at our institution with 2- or 4-hole side plates. We hypothesized that there would be a higher rate of failure associated with the use of 2-hole side plates in the manage-ment of unstable fractures.

Methods

All patients presenting to our level 1 trauma institution have prospective data collected in a database. This database includes demographic information; fracture type; duration of surgery; blood loss; length of stay in hospital; and follow-up data, including complications and reoperation. This study included all patients with stable and unstable pertrochanteric fractures treated between Jan. 1, 2004, and Apr. 30, 2009. Stable fractures were defined as AO/OTA type 31 A1 and A2.1, and unstable fractures were defined as AO/OTA type 31 A2.2, A2.3 and A3.

All surgeries were performed in a single institution by 1 of 5 staff surgeons, all of whom were subspecialty orthope-dic trauma surgeons. Resident and fellow trainees were also involved in all cases; however, surgeries were per-formed under the direct supervision of the senior staff sur-geon, who was present in the operating room at all times. All fractures were treated with 135° sliding hip screw (SHS; Synthes USA). The decision to use either a 2- or 4-hole side plate was based on surgeon preference in each case. At the time of the study, the preference was to use minimally invasive surgical techniques, favouring the 2-hole plate. However, there were no common criteria, and the decision was left entirely up to the surgeon. The plates were secured with 4.5 mm cortical screws.

Follow-up was attempted at intervals of 6 weeks until such time as fracture healing was determined both clinic-ally and radiographically.

Failure of management was defined as the need for re-operation, implant failure, failure of fixation and nonunion. Excessive shortening was not used, as we did not have the ability to correlate this with follow-up data.

Results

We identified a total of 369 cases of petrochanteric femur frac-tures treated during the study period. Nineteen patients died and were lost to follow-up, and 23 were excluded as they were not managed with a 2- or 4-hole side plate. There were there-fore 320 patients with 327 pertrochanteric femoral fractures available for analysis (252 women, 75 men, mean age 85.5 yr, mean American Society of Anesthesiologists score 3.07; Table 1). There were 208 stable and 119 unstable fractures.

Table 1. Patient demographics in the 4 treatment arms

Plate; fracture type Fractures, no. Average age, yr Average ASA

2 hole

Stable 127 83.6 2.98

Unstable 45 85.1 3.18

4 hole

Stable 81 87.1 3.08

Unstable 74 86.3 3.03

ASA = American Society of Anesthesiologists score.


RESEARCH


The average duration of surgery was 38.44 minutes for procedures using a 2-hole side plate, which was signifi-cantly shorter than surgeries performed with a 4-hole plate (average duration 51.45 min, p < 0.001).

The average change in hemoglobin pre- to postopera-tively for cases involving a 2-hole plate was 26 g/L, with a transfusion rate of 43%. This was significantly less than that in cases using a 4-hole plate, which had an average change in hemoglobin of 31.3 g/L (p = 0.004) and a trans-fusion rate of 60%.

The average length of stay in hospital for patients treated with a 2-hole side plate was 19 days, whereas that for patients treated with a 4-hole plate was 16 days (p = 0.10).

There were 3 deep infections, 2 of which occurred in patients initially managed with a 2-hole side plate. One of these infections was successfully treated with irrigation, débridement and temporary antibiotic beads. The other required serial débridements and eventual conversion to a total hip arthroplasty. The third infection occurred in a patient treated with a 4-hole plate who was also managed successfully with irrigation, débridement and temporary antibiotic beads.

Fracture management with a 2-hole side plate failed in 19 of 172 (11%) patients. Seven failures were due to implant failure (plate pull-out and/or screw breakage). Seven were due to a loss of fixation, with lag screw cut-out from the femoral head. There were 3 cases of nonunion and 2 cases of deep infection requiring reoperation.

Fracture management with a 4-hole side-plate failed in 12 of 155 (7.7%) patients. There was 1 case of implant fail-ure. Six cases were due to loss of fixation. Nonunion was diagnosed in 3 patients. There was 1 deep infection and 1 case of intraoperative fracture requiring revision.

The failure rate for stable fractures managed with a 2-hole plate was 8 of 127 (6.3%), and that for unstable fractures was 11 of 45 (24.4%). For stable fractures man-aged with a 4-hole side plate the failure rate was 4 of 81 (4.9%), and that for unstable fractures was 8 of 74 (10.8%; Table 2). There was no significant difference in failure rate between 2- and 4-hole fixation in patients with a stable

fracture pattern (p = 0.68). There was a significantly higher rate of failure in those with unstable fractures when treated with a 2-hole side plate (p = 0.048).

Discussion

Consistent with previous studies, we found that the less invasive procedure of using a 2-hole side plate resulted in reduced duration of surgery, blood loss and need for transfusion compared with the 4-hole plate. There was no difference, however, in the overall length of stay in hospi-tal between the 2 groups. This is likely a reflection of the premorbid function and medical comorbidities of these patients and the resulting difficulties in returning them to their previous level of independence postoperatively.

Overall, there was a relatively low rate of failure using both 2- and 4-hole side plates. This finding is also consis-tent with the results of published biomechanical and clin-ical studies.4–8,11–12 The previously reported clinical series, however, either compared the plates in the management of stable fractures specifically or had small samples of un stable fractures.

When we examined the failure rate allowing for fracture stability, there was a significantly higher rate of failure in patients with an unstable fracture pattern who were treated with a 2-hole side plate. This was in a much larger sample of patients with unstable fractures than previously reported.

The exact reason why 2-hole plates failed when used in patients with unstable fracture patterns is unclear, but it is interesting to note that there were 7 cases of implant fail-ure with a 2-hole plate compared with only 1 implant fail-ure with a 4-hole plate. It has been shown previously that most mechanical failures using SHS implants result in varus at the fracture site, which thereby increases tension at the screw-bone interface of the side plate.17 A longer plate with more screws may cope better with such forces.

Stable 2-part fracture patterns have minimal varus load with full weight bearing when adequately reduced. This is not the case, however, with comminuted unstable fractures that have lost their medial support, resulting in greater varus stress.5 These cases therefore have greater reliance on the fixation of the side plate to compensate for these increased forces.

conclusion

We believe, based on our experience, that stable intertrochan-teric fractures (AO/OTA 31A1 and A2.1) should be stabilized with a 2-hole side plate SHS because of shorter duration of surgery and less need for blood transfusion. For unstable pat-terns (AO/OTA A2.2, A2.3, A3), however, a 4-hole side plate is necessary to reduce the risk of mechanical failure.

Competing interests: P.J. O’Brien has received speaker fees from Zimmer, and his department receives academic funding from Depuy/Synthes. No other competing interests declared.

Table 2. Comparison of failure rates in patients with stable and unstable pertrochanteric fractures using 2- and 4-hole side plates

Group; no. (%)

Plate; fracture type Failure Fracture healed Total

2 hole

Stable 8 (6.3) 119 (93.7) 127

Unstable 11 (24.4) 34 (75.6) 45

4 hole

Stable 4 (4.9) 77 (95.1) 81

Unstable 8 (10.8) 66 (89.2) 74


RECHERCHE


Contributors: All authors designed the study, acquired and analyzed the data. D. Cruickshank and R. Baird wrote the article, which all authors reviewed and approved for publication.

References

1. Clawson DK. Trochanteric fractures treated by the sliding screw plate fixation method. J Trauma 1964;4:737-52.

2. Den Hartog BD, Bartal E, Cooke F. Treatment of the unstable intertrochanteric fracture. Effect of the placement of the screw, its angle of insertion, and osteotomy. J Bone Joint Surg Am 1991; 73:726-33.

3. Baumgaertner MR, Curtin SL, Lindskog DM, et al. The value of the tip-apex distance in predicting failure of fixation of pertrochan-teric fractures of the hip. J Bone Joint Surg Am 1995;77:1058-64.

4. Alobaid A, Harvey EJ, Elder GM, et al. Minimally invasive dynamic hip screw: prospective randomized trial of two techniques of insertion of a standard dynamic fixation device. J Orthop Trauma 2004;18:207-12.

5. Verhofstad MHJ, van der Werken C. DHS osteosynthesis for stable pertrochanteric femur fractures with a two-hole side plate. Injury 2004;35:999-1002.

6. DiPaola M, Rozbruch SR, Helfet DL. Minimal incision technique using a two-hole plate for fixation of stable intertrochanteric hip fractures. Orthopedics 2004;27:270-4.

7. Bolhofner BR, Russo PR, Carmen B. Results of intertrochanteric femur fractures treated with a 135-degree sliding screw with a two-hole side-plate. J Orthop Trauma 1999;13:5-8.

8. Riha D, Bartonicek J. Internal fixation of pertrochanteric fractures using DHS with a two-hole side-plate. Int Orthop 2010;34:877-82.

9. Reich SM, Jaffe WL, Kummer FJ. Biomechanical determination of the optimal number of fixation screws for the sliding hip screw plate. Bull Hosp Jt Dis 1993-1995;53:43-4.

10. Yian EH, Banerji I, Matthews LS. Optimal side plate fixation for unstable intertrochanteric hip fractures. J Orthop Trauma 1997; 11:254-9.

11. McLoughlin SW, Wheeler DL, Rider J, et al. Biomechanical evalu-ation of the dynamic hip screw with two- and four-hole side plates. J Orthop Trauma 2000;14:318-23.

12. Laohapoonrungsee A, Arpornchayanon O, Phornputkul C. Two-hole side-plate DHS in the treatment of intertrochanteric fracture: results and complications. Injury 2005;36:1355-60.

13. Bendo JA, Weiner LS, Strauss E, et al. Collapse of intertrochanteric hip fractures fixed with a sliding screw. Orthop Rev 1994;(Suppl):30-7.

14. Steinberg GL, Desai SS, Kornwitz NA, et al. The intertrochanteric hip fractures. A retrospective analysis. Orthopaedics 1998;11:265-73.

15. Baixauli F, Vicent V, Baixauli E, et al. A reinforced rigid device for unstable intertrochanteric fractures. Clin Orthop Relat Res 1999; (361):205-15.

16. Kim WY, Han CH, Park JI, et al. Failure of intertrochanteric frac-ture fixation with a dynamic hip screw in relation to pre-operative fracture stability and osteoporosis. Int Orthop 2001;25:360-2.

17. Spivak JM, Zukerman JD, Kummer FJ, et al. Fatigue failure of the sliding screw in hip fracture fixation. J Orthop Trauma 1991; 5:325-31.

CJS’s top viewed articles*

1. Research questions, hypotheses and objectives Farrugia et al. Can J Surg 2010;53(4):278-81 2. Complications associated with laparoscopic

sleeve gastrectomy for morbid obesity: a surgeon’s guide

Sarkhosh et al. Can J Surg 2013;56(5):347-52 3. Tracheostomy: from insertion to decannulation Engels et al. Can J Surg 2009;52(5):427-33 4. Managing complications associated with

laparoscopic Roux-en-Y gastric bypass for morbid obesity

Sahle Griffith et al. Can J Surg 2012;55(5):329-36 5. Treatment of an infected total hip replacement with the PROSTALAC system Scharfenberger et al. Can J Surg 2007;50(1):24-8 6. Hardware removal after tibial fracture has healed Sidky and Buckley Can J Surg 2008;51(4):263-8 7. Blinding: Who, what, when, why, how? Karanicolas et al. Can J Surg 2010;53(5):345-8 8. The introduction of new technology Waddell Can J Surg 2004;47(4):246-7 9. Pharmacological management

of postoperative ileus Zeinali et al. Can J Surg 2009;52(2):153-710. Complications of Meckels diverticula in adults Dumper et al. Can J Surg 2006;49(5):353-7

*Based on page views on PubMed Central of research, reviews, commentaries and discussions in surgery. Updated Sept. 12, 2014.




Laparoscopic right hemicolectomy with complete mesocolic excision provides acceptable perioperative outcomes but is lengthy — analysis of learning curves for a novice minimally invasive surgeon

Background: Associated with reduced trauma, laparoscopic colon surgery is an alterna-tive to open surgery. Furthermore, complete mesocolic excision (CME) has been shown to provide superior nodal yield and offers the prospect of better oncological outcomes.

Methods: All oncologic laparoscopic right colon resections with CME performed by a single surgeon since the beginning of his surgical practice were retrospectively ana-lyzed for operative duration and perioperative outcomes.

Results: The study included 81 patients. The average duration of surgery was 220.0 (range 206–233) minutes. The initial durations of about 250 minutes gradually decreased to less than 200 minutes in an inverse linear relationship (y = –0.58x × 248). The major complication rate was 3.6% ± 4.2% and the average nodal yield was 31.3 ± 4.1. CumulativeSum analysis showed acceptable complication rates and oncological results from the beginning of surgeon’s laparoscopic career.

Conclusion: Developing laparoscopic skills can provide acceptable outcomes in advanced right hemicolectomy for a surgeon who primarily trained in open colorectal surgery. Operative duration is nearly triple that reported for conventional laparoscopic right hemi-colectomy. The slow operative duration learning curve without a plateau reflects complex anatomy and the need for careful dissection around critical structures. Should one wish to adopt this strategy either based on some available evidence of superiority or with intention to participate in research, one has to change the view of right hemicolectomy being a rather simple case to being a complex, lengthy laparoscopic surgery.

Contexte : La chirurgie du côlon par laparoscopie, qui réduit les traumatismes, est une solution de rechange à la chirurgie ouverte. De plus, il a été démontré que l’excision mésocolique complète (EMC) optimise le curage ganglionnaire et offre la perspective de meilleurs résultats oncologiques.

Méthodes : On a examiné rétrospectivement la durée de l’opération et les résultats périopératoires de toutes les résections du côlon droit réalisées par laparoscopie avec EMC pratiquées par un seul chirurgien depuis le début de sa carrière.

Résultats : L’étude a été menée auprès de 81 patients. La durée moyenne de l’intervention chirurgicale était de 220 minutes (intervalle de 206 à 233 minutes). Au début, l’intervention durait environ 250 minutes; avec le temps, sa durée a progres-sivement diminué de sorte qu’à la fin, elle était de moins de 200 minutes, d’après une relation linéaire négative (y = –0,58x × 248). Le taux de complications graves s’est établi à 3,6 % ± 4,2 % et le nombre moyen de nœuds lymphatiques excisés a été de 31,3 ± 4,1. En utilisant la méthode d’analyse des sommes cumulées, on a observé un taux de complications et des résultats oncologiques acceptables depuis le début de la carrière du chirurgien en laparoscopie.

Conclusion : En perfectionnant sa technique laparoscopique, un chirurgien formé principalement en chirurgie colorectale ouverte peut produire des résultats acceptables dans les cas d’hémicolectomie droite avancée. La durée de l’intervention chirurgicale est presque le triple de celle d’une hémicolectomie droite laparoscopique classique. La courbe d’apprentissage lente sans plateau montre bien la complexité des structures anatomiques et la nécessité de faire preuve de prudence lors de la résection autour de structures vitales. Quiconque souhaite adopter cette méthode, soit en raison de données démontrant sa supériorité ou dans le but de participer à une recherche, doit adopter une nouvelle perspective, c’est-à-dire que l’hémicolectomie droite laparoscopique n’est pas une intervention simple, mais une chirurgie complexe qui prend beaucoup de temps.

George Melich, MD* Duck Hyoun Jeong, MD† Hyuk Hur, MD† Seung Hyuk Baik, MD† Julio Faria, MD* Nam Kyu Kim, MD† Byung Soh Min, MD†‡

From the *Jewish General Hospital, McGill University, Montréal, Que., †Department of Surgery, Yonsei University College of Medicine, Seoul, South Korea, and the ‡Robot and Minimally Invasive Surgery Center, Yonsei University Health System, Seoul, South Korea

The data presented in this study have been presented as a podium presenta-tion during the Canadian Association of General Surgeons annual conference in Calgary, Alta., Sept. 13–16, 2012.

Accepted for publication Apr. 1, 2014

Correspondence to: B.S. Min Department of Surgery Yonsei University College of Medicine 50 Yonsei-ro Seodaemun-gu Seoul, Republic of Korea, 120-752 [email protected]

DOI: 10.1503/cjs.002114

laparo-melich.indd 331 14-09-16 10:57 AM

RECHERCHE


L aparoscopic colon surgery has been shown to offer clear evidence of benefit when compared to open surgery. These benefits include reduced length of

hospital stay, earlier return of bowel function as well as reduced blood loss and pain without compromising quality of oncological resection and nodal yield.1–4 Furthermore, complete mesocolic excision (CME) has been demon-strated to provide superior nodal yield5 and offers pros-pects of better oncological outcomes than non-CME sur-gery.6 The purpose of this study is 2-fold: first, to analyze laparoscopic CME right hemicolectomy with respect to operative durations and perioperative outcomes for a nov-ice minimally invasive colorectal surgeon, and second, to draw conclusions with respect to the feasibility of adopting advanced laparoscopic right hemicolectomy by a surgeon who primarily trained in open colon surgery.

Methods

From 2008–2011, prospective data on consecutive laparo-scopic right hemicolectomies with CME for colon cancer were entered into a database and were later extracted for retrospective analysis. The surgical approach was approved by departmental committee, and patients pro-vided informed consent.

All surgeries were performed by a single colorectal sur-geon (B.S.M.) who was primarily trained in open colorectal surgery with general minimally invasive surgery (MIS) training in laparoscopic appendectomy and cholecystec-tomy. The surgeon had completed formal laparoscopic and robotic courses and had support from established MIS colorectal staff at his institution. Furthermore, the sur-geon’s prior training involved open CME. The present series covers the beginning of his MIS colorectal practice.


Patient-specific data and outcome measures were analyzed using standard statistics. CumulativeSum (CUSUM) plots were used to track major complications and failures to har-vest at least 12 lymph nodes. The CUSUM plots are com-monly used to assess learning progress and proficiency in the medical field across many specialties, including colorec-tal surgery.7–9 They can be a valuable tool to rapidly depict unfavourable trends. The CUSUM plots are a visual repre-sentation of cumulative failures and successes; the plot starts at zero and goes down with success or up with failure. In its simplest form, as used in this study, the plot will decrease by a fraction consistent with established acceptable failure rate and up by a fraction consistent with a success rate. For example, if an acceptable rate of major complication is 10%, the graph will go down only by 0.1 units with a success and up by 0.9 units with a failure. Failure is therefore depicted more dramatically than success. While a plot centred on the zero line indicates a rate consistent with an established

acceptable failure rate, upward and downward sloping plots indicate less and more favourable rates, respectively. A V-mask is an overlay shape in the form of a V on its side that is superimposed on the graph of the CUSUM in order to determine an out of control process. Minitab 15 statistical software was used to generate the CUSUM plots with the V-mask centred on the last case using standard settings, which assume Montgomery approximation.10 In the present study, for the purpose of generating a CUSUM plot, con-version to open surgery, perioperative death, hemorrhage, need for reoperation within 1 month and any leak or any type of intra-abdominal abscess were tracked and were con-sidered operative failures. Conversion to open surgery was added to this category in order to simplify tracking operative failures for the CUSUM plots. Although, rates of these complications vary greatly, we chose an acceptable failure rate of 5%, as this rate would pass the bar set by all large trials.11–13 The American Joint Committee on Cancer (AJCC) recommends assessment of 12 or more nodes for accurate staging.14 Despite available reports on average yields of various right hemicolectomy procedures, to our knowledge no studies report the rate of failure to retrieve at least 12 nodes in right hemicolectomy. In their study of learning curves in laparoscopic sigmoidectomy, Choi and colleagues15 suggested a 10% lymph node retrieval failure rate for creating CUSUM plots.15 We set the failure rate to retrieve at least 12 lymph nodes at 10%, with the caveat that our actual rate could serve as the first reported benchmark for this parameter.

CME laparoscopic right hemicolectomy

Although some adjustments were made during the initial period of about 15 cases, the following is a general description of the surgical technique used.

A 10 mm transumbilical camera port is placed through a 1 cm midline incision. This incision is later extended supra- and infraumbilically for specimen extraction. The surgeon works mostly between the patient’s legs, using bilateral lower abdominal ports. An assistant applies trac-tion as needed through a left upper quadrant (LUQ) port.

The root of the small bowel mesentery is lifted and the ileocecal junction is displayed. Adhesions and the periton-eum lateral to the ascending colon are incised past the hepatic flexure, staying between the embryological planes just anterior to the Gerota fascia, duodenum and ureter. The lateral mobilization proceeds carefully over the duo-denum and pancreas with the landmark for the completion of lateral mobilization being the superior mesenteric vein.

The medial dissection begins by incising the base of the mesentery. The assistant’s grasper is used on the bloodless fold of Treves at the ileocecal junction to stretch up the mesentery toward the right lower quadrant port, lifting up the vessels from the retroperitoneum. This brings out a sulcus between the medial side of the ileocolic pedicle and


RESEARCH


the retroperitoneum. An advanced energy device can even-tually be used to further open the peritoneal opening and to isolate the vessels.

The preferred dissecting and sealing device is the curved EnSeal device with cutting blade (Ethicon Endo-Surgery). This is mostly for its ergonomics and ability to retain control over the length of a burn, allowing for faster work with avascular tissue.

When completely dissected, the ileocolic vessels are clipped at the root and transected. Having left a piece of gauze over the duodenum and pancreas from the lateral side at the conclusion of lateral dissection helps guide the depth of dissection and further assists in maintaining the correct dissection plain. The mesenteric dissection line is then extended further cephalad up to the origin of the right colic artery, if present, and toward the middle colic artery, which is always present.

The middle colic artery is always dissected to its origin from the superior mesenteric artery for maximal nodal yield. In limited resections involving very proximal lesions, dissection is often carried out further along the middle colic artery up to its bifurcation and only the right branch of the middle colic artery is transected. Lateral to the middle colic artery, the right colic vein, coursing anteriorly from the Henle trunk, can usually be identified and transected. All the central nodal tissue is then swept with the specimen.

With traction on the colon, the lesser sac is entered and the gastrocolic tissue is divided. The progress is continued along the mobilization plane, drawing the hepatic flexure inferiorly and medially. Generous distal resection margin is transected through the LUQ port using an endostapler. The remaining mesentery can then be transected using an advanced energy-based device, and the terminal ileum can be transected intracorporeally using an endostapler.

The specimen is put into an endo-bag, which is closed tight and parked over the liver for later retrieval through a 3 cm midline transumbilical incision. An intracorporeal anastomosis is performed, eliminating problems with extra-corporeal delivery and unnecessary traction on the mesen-tery. The terminal ileum and transverse colon are aligned in side-to-side isoperistaltic fashion, and enterotomies are made for the insertion of an endostapler. Firing an endosta-pler through these enterotomies creates the crotch of the final anastomosis. The resulting common enterotomy is then put under tension using 3 traction sutures, and the enterotomy is closed with another load of endostapler com-pleting the side-to-side, functional end-to-end anastomosis. Figure 1 shows an intracorporeal view of dissection extent, and Figure 2 shows a typical retrieved specimen.

Results

The study included 81 patients. Data summarizing preop-erative parameters and operative outcomes are shown in Table 1. Outcome results feature a major complication

rate of 3.6%, which includes conversions, leaks/intra-abdominal abscesses and a need for reoperation for an early trocar hernia. The average nodal yield was 31.3. The average duration of surgery was 220.0 minutes. The dura-tion of surgery curve (Fig. 3), shows that the initial dura-tion of surgery of about 250 minutes gradually decreased to less than 200 minutes by the 81st case in an inverse lin-ear relationship with successive cases (y = –0.58 × 248). Finally, CUSUM plots (Fig. 4 and Fig. 5) indicate accept-able nodal yields and complication rates from the begin-ning of surgeon’s laparoscopic practice.

Discussion

While adoption of total mesorectal excision in the man-agement of rectal cancer has led to significant improve-ment in survival, the survival rates for colon cancer have

Fig. 1. Intracorporeal view of dissection extent featuring smooth superior mesenteric artery (SMA) and superior mesenteric vein (SMV) skeletonized all the way up to the pancreas and showing the individual branches ligated at their origin.

Trunk of Henle

Stump of middle colic vein

Lower border of pancreas

SMV Stump of middle colic artery

SMA

Stump of ileocolic artery

Fig. 2. Example of a retrieved specimen featuring clean peritoneal surfaces and maximal distance from the central tie to the tumour.


RECHERCHE


improved only slightly in the last 2 decades; disease-free survival rates for rectal cancer have even surpassed those for colon cancer in some studies.16–20 The reported sur-vival rates for colon cancer vary widely among centres but seem higher in centres that routinely perform stan-dardized, extensive colonic resections6,21,22 — a fact that may be subject to selection bias. Some of the most intriguing results come from Erlangen, Germany, reporting an 18% improvement in 5-year survival fol-lowing the standardization of colonic resection to include CME.23 This result seems to be mostly attribut-able to surgery, as their data originate from a period before instigating adjuvant chemotherapy.23,24 Although most of these results are based only on regional, non-comparative studies and a multitude of other contribut-ing factors, such as patient characteristics, regional diet and type of adjuvant care received, play a role, the pub-lished outcomes suggest probable room for optimizing surgical management. To our knowledge, no readily available studies have been published that specifically address laparoscopic colectomies with CME in the con-text of long-term survival.

Future research is necessary to quantify the effect CME has on survival rates for right-sided colon cancer.

Table 1. Preoperative parameters and perioperative outcomes (n = 81)

Factor Mean (95% CI)*

Preoperative parameters

Age, yr 63.7 (60.7–66.76)

Sex, % male 58.0 (47.3–68.8)

BMI 23.3 (22.60–23.92)

Stage, %

0 1.2 (0.0–3.6)

I 25.9 (16.4–35.5)

II 33.3 (23.1–43.6)

III 35.8 (25.4–46.2)

IV 3.7 (0.0–7.8)

Anesthesia ASA score, median (min–max)

2 (1–3)

Operative outcomes

OR time, min 220 (206–233)

EBL, mL 116 (83–148)

No. of lymph nodes harvested 31.3 (27.2–35.4)

Lymph node yield < 12, % 7.4 (1.7–13.10)

Major complications, % 3.7 (0.0–7.8)

Conversion to open† 0.0

Death/hemorrhage 0.0

Leak or any intra-abdominal abcess 2.5 (0.0–5.9)

Need for reoperation within 1 mo (incarcerated trochar site hernia)

1.2 (0.0–3.6)

Positive resection margin 0.0

ASA = American Society of Anesthesiologists; BMI = body mass index; CUSUSM = CummulativeSum; CI = confidence interval; EBL = estimated blood loss; OR = operating room. *Unless otherwise indicated. †Conversion to open was added to this category in order to track operative failures, as defined for the CUSUM plots.

Fig. 4. Outcome CummulativeSum curve with V-mask tracking failure to harvest at least 12 nodes, assuming an acceptable failure rate of 10%.

Nod

e ha

rves

t fa

ilure

Cum

ulat

iveS

um

5.0

2.5

0.0

–2.5

–5.0

–7.5

Case number

1 9 17 25 33 41 49 57 65 73 81

Fig. 3. Total duration of surgery. Ten-case moving average with best fit curve. OR = operating room.

y = –0.5794x + 247.94R² = 0.378

0

50

100

150

200

250

300

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81

OR

tim

e, m

in

Case number

Fig. 5. Outcome CummulativeSum (CUSUM) curve with V-mask tracking major complications, as featured in Table 1, assuming an acceptable failure rate of 5%.

Maj

or c

ompl

icat

ion

Cum

ulat

iveS

um

2

1

0

–1

–2

–3

–4

Case number

1 9 17 25 33 41 49 57 65 73 81


RESEARCH


However, this was not the purpose of the present study. The intent of this study was to provide guidance to sur-geons wishing to adopt this strategy based on the previ-ously published evidence by showing that laparoscopic CME is possible with acceptable perioperative outcomes and outstanding nodal yields when adhering to good surgical principles. The results presented in this report suggest that a laparoscopic right-sided hemicolectomy with CME can be performed safely by a colorectal sur-geon who primarily trained in open colorectal surgery in a setting where the surgeon attended a formal lapa-roscopic course and where adequate laparoscopic proc-toring is available. This finding is demonstrated by CUSUM curves showing that perioperative safety and nodal yields were not compromised even early in the surgeon’s practice.

The average nodal yield of 31.3 is consistent with previously published reports of 30 lymph nodes with right hemicolectomy and CME and is superior to aver-age yields of fewer than 20 lymph nodes with conven-tional surgery.5 We report a failure rate to retrieve at least 12 lymph nodes of 7.4% to serve as, to our know-ledge, a first reported reference rate for this type of surgery. Although our results offer insight into the adoption of MIS among surgeons trained primarily in open surgery, they serve only as a guide because they are not necessarily generalizable as they originate from a single surgeon’s experience operating on a specific patient population.

A lateral to medial approach was used in our study. Not only is such an approach familiar from open surgery, it also helps ensure a correct dissection plane, which is often lost when performing CME from a medial approach. To sur-geons who prefer high ligation of the ileocolic vessels early during the operation for further theoretical oncological reasons, we recommend simple ligation of the vessels using the medial approach followed by lateral mobilization to ensure a correct dissection plane before completing the medial dissection.

Duration of surgery remains one of the largest obsta-cles for laparoscopic CME. The operative duration learn-ing curve reveals initial durations of about 250 minutes, which is more than double the durations reported for conventional laparoscopic right hemicolectomy per-formed by experienced laparoscopic surgeons.25 However, the duration decreased to below 200 minutes by the end of the study. Reflecting complex anatomy and the need for careful dissection around critical anatomic structures, especially during central vessel ligation, the operative duration learning curve reveals a rather slow linear inverse relationship between duration of surgery and suc-cessive operative cases. This relationship continues being linear without reaching a plateau, even at the end of the study, indicating potential for further improvement beyond the initial 81 cases.

ConClusion

In the current knowledge milieu where laparoscopic colon surgery provides superior perioperative outcomes and CME further offers prospects of better oncological out-comes, this data set offers encouragement in terms of feas-ibility to surgeons primarily trained in open colon surgery who wish to expand their skill set and can justify the addi-tional time required. The question remaining is whether surgeons in North America should first adopt open CME or whether it is feasible to learn laparoscopic CME directly.Competing interests: None declared.

Contributors: G. Melich, H. Hur, S.H. Baik, J. Faria, N.K. Kim and B.S. Min designed the study. D.H. Jeong and B.S. Min acquired the data, which G. Melich, D.H. Jeong, J. Faria and B.S. Min analyzed. G. Melich and B.S. Min wrote the article, which all authors reviewed and approved for publication.

References

1. Reza MM, Blasco JA, Andradas E, et al. Systematic review of lapa-roscopic versus open surgery for colorectal cancer. Br J Surg 2006;93:921-8.

2. Clinical Outcomes of Surgical Therapy Study Group. A comparison of laparoscopically assisted and open colectomy for colon cancer. N Engl J Med 2004;350:2050-9.

3. Guller U, Jain N, Hervey S, et al. Laparoscopic vs open colectomy: outcomes comparison based on large nationwide databases. Arch Surg 2003;138:1179-86.

4. Aly EH. Laparoscopic colorectal surgery: summary of the current evidence. Ann R Coll Surg Engl 2009;91:541-4.

5. West NP, Hohenberger W, Weber K, et al. Complete mesocolic excision with central vascular ligation produces an oncologically superior specimen compared with standard surgery for carcinoma of the colon. J Clin Oncol 2010;28:272-8.

6. Hohenberger W, Weber K, Matzel K, et al. Standardized surgery for colonic cancer: complete mesocolic excision and central liga-tion — technical notes and outcome. Colorectal Dis 2009;11:354-64.

7. Lim TO, Soraya A, Ding LM, et al. Assessing doctors’ competence: application of CUSUM technique in monitoring doctor’s perform-ance. Int J Qual Health Care 2002;14:251-8.

8. Colquhoun PHD. CUSUM analysis of J-pouch surgery reflects no learning curve after board certification. Can J Surg 2008;51:296-9.

9. Bokhari MB, Patel CB, Ramos-Valadez DI, et al. Learning curve for robotic-assisted laparoscopic colorectal surgery. Surg Endosc 2011;25:855-60.

10. Montgomery DC. Introduction to Statistical Quality Control. 4th ed. New York (NY): Wiley; 2000.

11. Lacy AM, Garcia-Valdecasas JC, Delgado S, et al. Laparoscopy-assisted colectomy versus open colectomy for treatment of non- metastatic colon cancer: a randomised trial. Lancet 2002;359:2224-9.

12. Guillou PJ, Quirke P, Thorpe H, et al. Short-term endpoints of conventional versus laparoscopic-assisted surgery in patients with colorectal cancer (MRC CLASICC trial): multicentre, randomised controlled trial. Lancet 2005;365:1718-26.

13. Veldkamp R, Kuhry E, Hop WC, et al. Laparoscopic surgery versus open surgery for colon cancer: short-term outcomes of a ran-domised trial. Lancet Oncol 2005;6:477-84.

14. Greene FLP, Page DL, Fleming ID, et al. AJCC Cancer Staging Manual. 6th ed. Philadelphia (PA): Lippincott Raven; 2002:107–17.

15. Choi DH, Jeong WK, Lim SW, et al. Learning curves for laparo-scopic sigmoidectomy used to manage curable sigmoid colon cancer: single-institute, three-surgeon experience. Surg Endosc 2009;23:622-8.


RECHERCHE


16. Martling AL, Holm T, Rutqvist LE, et al. Effect of a surgical train-ing programme on outcome of rectal cancer in the County of Stockholm. Lancet 2000;356:93-6.

17. Kapiteijn E, Putter H, van de Velde CJH, et al. Impact of the intro-duction and training of total mesorectal excision on recurrence and survival in rectal cancer in the Netherlands. Br J Surg 2002; 89:1142-9.

18. Wibe A, Moller B, Norstein J, et al. A national strategic change in treatment policy for rectal cancer — implementation of total meso-rectal excision as routine treatment in Norway: a national audit. Dis Colon Rectum 2002;45:857-66.

19. Birgisson H, Talback M, Gunnarsson U, et al. Improved survival in cancer of the colon and rectum in Sweden. Eur J Surg Oncol 2005;31:845-53.

20. Iversen LH, Norgaard M, Jepsen P, et al. Trends in colorectal cancer

survival in northern Denmark: 1985-2004. Colorectal Dis 2007; 9:210-7.

21. Pramateftakis MG. Optimizing colonic cancer surgery: high liga-tion and complete mesocolic excision during right hemicolectomy. Tech Coloproctol 2010;14:S49-51.

22. Kobayashi H, Enomoto M, Higuchi T, et al. Clinical significance of lymph node ratio and location of nodal involvement in patients with right colon cancer. Dig Surg 2011;28:190-7.

23. Hohenberger W, Reingruber B, Merkel S. Surgery for colon cancer. Scand J Surg 2003;92:45-52.

24. Gall FP, Hermanek P. Wandel und derzeitiger Stand der Behand-lung des colorectalen Carcinoms. Chirurg 1992;63:227-34.

25. Senagore AJ, Delaney CP, Brady KM, et al. Standardized approach to laparoscopic right colectomy: outcomes in 70 consecutive cases. J Am Coll Surg 2004;199:675-9.

How you can get involved in the CMA!The CMA is committed to providing leadership for physicians and promoting the highest standard of health and health care forCanadians. To strengthen the association and be truly representative of all Canadian physicians the CMA needs to hear from mem-bers interested in serving in elected positions and on appointed committees and advisory groups. The CMA structure comprises both governing bodies and advisory bodies either elected by General Council or appointed by the CMA Board of Directors. The Board ofDirectors — elected by General Council — has provincial/territorial, resident and student representation, is responsible for the over-all operation of the CMA and reports to General Council on issues of governance.

CMA committees advise the Board of Directors and make recommendations on specific issues of concern to physicians and the pub-lic. Five core committees mainly consist of regional, resident and student representation while other statutory and special commit-tees and task forces consist of individuals with interest and expertise in subject-specific fields. Positions on one or more of thesecommittees may become available in the coming year.

For further information on how you can get involved please go to https://www.cma.ca/en/Pages/get-involved-in-cma.aspx, or contact

Cherise AraujoCorporate and Governance Services

Canadian Medical Association1867 Alta Vista Drive, Ottawa ON K1G 5W8

Fax 613 526-7570, Tel 800 663-7336 [email protected]

By getting involved, you will have an opportunity to make a difference.

We hope to hear from you!

laparo-melich.indd 336 14-09-16 12:20 PM



The clinical importance of different localizations of the papilla associated with juxtapapillary duodenal diverticula

Background: Previous studies have evaluated the presence of juxtapapillary duodenal diverticula (JPDD) and the association with pancreatobiliary disease, but not the asso-ciation of the papilla with an existing JPDD. We investigated the association of differ-ent localizations of the papilla with JPDD.

Methods: We studied patients in whom JPDD was detected during endoscopic ret-rograde cholangiopancreatography. Patients were classified into 3 groups: 1) papilla located inside the diverticulum, 2) papilla located at the edge of the diverticulum and 3) papilla located closer than 3 cm to the diverticulum. The patients were examined with respect to localization of papilla–diverticula and to the association of the localiza-tion with pancreaticobiliary disease.

Results: We enrolled 274 patients in our study. Biliary stone disease more frequently existed in group 3. The number of patients presenting with obstructive jaundice was higher in groups 2 (83.6%) and 3 (83.3%) than group 1 (66%). Cholangitis was more common in group 1 (21.3%) than in groups 2 (6.7%) and 3 (2.3%). The presence of biliary stone disease among patients presenting with pancreatitis was significantly dif-ferent between groups 1 and 3 (p = 0.013) and between groups 2 and 3 (p = 0.017). The common bile duct more frequently contained stones or sludge in group 3 than in groups 1 and 2.

Conclusion: When the papilla is located close to the JPDD, the incidence of biliary stone disease decreases, and pancreatobiliary diseases are caused mostly in the absence of biliary stone disease.

Contexte : Des études antérieures ont évalué la présence de diverticules duodénaux juxtapapillaires (DDJP) et leur lien avec la maladie pancréatobiliaire, mais n’ont pas analysé le lien entre la papille et les DDJP existants. Nous avons analysé le lien entre diverses localisations de la papille et les DDJP.

Méthodes : Nous avons étudié des patients chez qui des DDJP ont été détectés lors d’une cholangiopancréatographie endoscopique rétrograde. Les patients ont été clas-sés en 3 groupes : 1) papille à l’intérieur du diverticule, 2) papille à l’extrémité du diverticule et 3) papille à moins de 3 cm du diverticule. L’examen a donc porté sur la localisation de la papille par rapport aux diverticules et sur le lien entre sa localisation et la maladie pancréatobiliaire.

Résultats : Nous avons inscrit 274 patients à notre étude. La cholélithiase s’observait davantage dans le groupe 3. Le nombre de patients souffrant d’ictère obstructif était plus élevé dans les groupes 2 (83,6 %) et 3 (83,3 %) que dans le groupe 1 (66 %). La cholangite était plus fréquente dans le groupe 1 (21,3 %) que dans les groupes 2 (6,7 %) et 3 (2,3 %). Le taux de cholélithiase chez les patients souffrant de pancréatite était significativement différent entre les groupes 1 et 3 (p = 0,013) et entre les groupes 2 et 3 (p = 0,017). Il y avait plus de calculs ou de boue biliaires dans le canal cholédoque des patients du groupe 3 que dans ceux des groupes 1 et 2.

Conclusion : Lorsque la papille est située près des DDJP, l’incidence de la cholélithi-ase diminue, et les maladies pancréatobiliaires sont pour la plupart causées en l’absence de cholélithiase.

Bunyami Ozogul, MD Gurkan Ozturk, MD Abdullah Kisaoglu, MD Bulent Aydinli, MD Mehmet Yildirgan, MD Sabri Selcuk Atamanalp, MD

From the Department of General Surgery, Medical Faculty, Ataturk University, Erzurum, Turkey


Correspondence to: B. Ozogul Department of General Surgery Ataturk University Medical Faculty 25240, Erzurum, Turkey [email protected]

DOI: 10.1503/cjs.021113

clinic-ozogul.indd 337 14-09-16 11:02 AM

RECHERCHE


D uodenal diverticula (DD) are classified as primary (true) or secondary (false) diverticula. Primary diverticula are mostly solitary and can be observed

in the second part of the duodenum, in the ampulla vateri region (periampullary diverticula).1,2 They are also called juxtapapillary duodenal diverticula (JPDD). The clinical importance of JPDD originates from its association with the papilla and pancreaticobiliary disease. Several studies have suggested that JPDD are the reason for biliary stone disease.2,3 However, the association of the papilla with the diverticula and the effect of different positions of the papilla on biliary stone disease have not been investigated. To our knowledge, this association was first investigated in an earlier study conducted in our clinic.4 The present paper presents further results of this investigation.

Methods

This study was designed in a retrospective manner. We reviewed the cases of patients admitted to the Endoscopy Unit of the Department of General Surgery, Ataturk University School of Medicine, between May 1999 and December 2007 for endoscopic retrograde cholangiopancreatography (ERCP), and we enrolled those in whom JPDD were detected during ERCP. We noted the age and sex of the patients, indications for ERCP and endoscopic sphincterotomy (ES), the association of the JPDD with the papilla, laboratory values, cannulation success of the biliary tract and the diameter and contents of the common bile duct (CBD). We examined the localization of the papilla–diverticula and the association of the localization with pancreaticobiliary disease. The indications for ERCP were obstructive jaundice, cholangitis and pancreatitis. Patients who had gallbladder stones (including patients who previously underwent cholecystectomy for known gallbladder stones and patients who had a gallbladder stone and were not operated on at the time when the study was conducted), CBD stones, or both were considered to have biliary stone disease. Obstructive jaundice was defined as hyperbilirubinemia caused by mechanical obstruction of the biliary tract; cholangitis was defined as hyperbilirubinemia accompanied by fever and leucocytosis; and pancreatitis was defined as strongly suggestive evidence for pancreatitis of biliary origin (radiological and laboratory findings). Patients with known hepatocellular diseases, such as viral or toxic hepatitis, cirrhosis, hepatic or biliary malignancies, or hepatic or biliary benign masses, patients using medication influencing the hepatocellular functions, and patients who were operated on previously for a biliary tract disease (not cholecystectomy) were excluded from the study. Patients were classified according to the location of the papilla and diverticula into 3 groups, as done by Yildirgan and colleagues:4 1) papilla located inside the diverticulum, 2) papilla located at the edge of the diverticulum and 3) papilla located closer than 3 cm to the divertic

ulum. Patients with a papilla far away from the diverticulum were excluded. The patients were followed for at least 18 (range 18–24) months.


We conducted our analyses using SPSS software version 12.0 for Windows. Data were compared among the 3 groups. In addition, the association between indications for ERCP and biliary stone disease were investigated within groups. We conducted Student t tests for continuous variables and the χ2 test or Fisher exact test for categorical variables. We considered results to be significant at p < 0.05.

Results

A total of 2327 patients underwent ERCP in our endoscopy unit during our study period. Of these, 274 (11.7%) had JPDD. Twentyfive patients did not meet the inclusion criteria and were excluded. From the remaining 249 patients with JPDD, 103 (41.3%) were in group 1, 104 (41.7%) were in group 2, and 42 (17%) were in group 3.

The mean age; sex; indications; mean levels and activities of serum total blirubin, conjugated bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), γglutamyl transferase (GGT) and alkaline phosphatase (ALP); deep cannulation success of the CBD; and mean diameter of the CBD are shown in Tables 1–4.

In group 1 (n = 103), 38 (36.9%) patients had biliary stones. Twelve (31.6%) of them had only gallbladder stones, 17 (44.7%) had both CBD and gallbladder stones, and 9 (23.7%) had only CBD stones.

In group 2 (n = 104), 35 (33.6%) patients had biliary stones. Six (17.1%) of them had only gallbladder stones, 19 (54.3%) had both CBD and gallbladder stones, and 10 (28.6%) had only CBD stones.

In group 3 (n = 42), 33 (78.6%) patients had biliary stones. Eight (24.2%) of them had only gallbladder stones, 19 (57.6%) had both CBD and gallbladder stones, and 6 (18.2%) had only CBD stones.

The number of patients presenting with obstructive jaundice was higher in groups 2 (83.6%) and 3 (83.3%) than in group 1 (66%; both p = 0.016). When the presence of biliary stone disease was compared among patients presenting with obstructive jaundice, patients in group 3 had a higher incidence of biliary stone disease than patients in the other 2 groups (both p = 0.001), and there was no difference between groups 1 and 2.

The number of patients who presented with cholangitis was significantly higher in group 1 (21.3%) than in groups 2 (6.7%, p = 0.011) and 3 (2.3%, p = 0.001). Among patients with cholangitis, 22.7% in group 1, 57.1% in group 2 and 100% in group 3 had biliary stone disease. There was a significant difference between groups 1 and 2 (p = 0.013), 1 and 3 (p = 0.001), and 2 and 3 (p = 0.014).


RESEARCH


There was no difference among the groups in the pres-ence of pancreatitis. The presence of biliary stone disease among patients presenting with pancreatitis was signifi-cantly different between groups 1 (38.4%) and 3 (83.3%,

p = 0.013) and between groups 2 (50%) and 3 (83.3%, p = 0.017; Table 1).

The CBD more frequently contained stones or sludge in group 3 than in the other groups (both p = 0.016).

Table 1. Shows age, sex, cannulation success and CBD diameter

Characteristic Group 1, n = 103 Group 2, n = 104 Group 3, n = 42 Total, n = 249

Age, mean (IQR), yr 63.1 (31–80) 66.8 (34–85) 64.1 (29–76) 64.7 (29–85)

Sex, male:female 36:67 41:63 16:24 93:154

Cannulation success on first attempt, no. (%)

88 (85.4) 92 (88.4) 38 (90.4) 218 (87.5)

CBD diameter, mean, mm 14.6 14.3 15.2 14.7

CBD = common bile duct; IQR = interquartile range.

Table 2. Indications for intervention

Group; no. (%)

Indication Group 1, n = 103 Group 2, n = 104 Group 3, n = 42 Total, n = 249

Obstructive jaundice

Total 68 (66) 87 (83.6) 35 (83.3) 190 (76.3)

BSD 28 (41.1) 26 (29.8) 27 (77.1) 81 (42.6)

Cholangitis

Total 22 (21.3) 7 (6.7) 1 (2.3) 30 (12)

BSD 5 (22.7) 4 (57.1) 1 (100) 10 (33.3)

Biliary pancreatitis

Total 13 (12.6) 10 (9.6) 6 (14.2) 29 (11.6)

BSD 5 (38.4) 5 (50) 5 (83.3) 15 (51.7)

BSD = biliary stone disease.

Table 3. Patient laboratory data

Group; mean

Laboratory data Group 1, n = 103 Group 2, n = 104 Group 3, n = 42 Total, n = 249

Bilirubin, μmol/L

Total 75.60 71.49 68.07 68.59

Conjugated 28.56 33.35 28.05 30.44

AST, μkat/L 1.15 1.29 0.94 1.09

ALT, μkat/L 1.30 1.45 1.19 1.29

GGT, μkat/L 5.68 5.32 4.03 4.65

ALP, μkat/L 5.88 6.20 5.69 5.60

ALT = alanine amino transferase; ALP = alkaline phosphatase; AST = aspartate amino transferase; GGT = γ-glutamyl transferase.

Table 4. Common bile duct content and biliary stone presence

Group; no. (%)

Presence Group 1, n = 103 Group 2, n = 104 Group 3, n = 42 Total, n = 249

CBD content

None 77 (74.7) 75 (72.1) 17 (40.4) 169 (67.8)

Stone or sludge 26 (25.3) 29 (27.9) 25 (59.6) 80 (32.7)

Biliary stone

Gallbladder stone only 12 (11.6) 6 (5.7) 8 (19) 26 (10.4)

CBD stone only 9 (8.7) 10 (9.6) 6 (14.2) 25 (10)

Gallbladder and CBD stone 17 (16.5) 19 (18.2) 19 (45.2) 55 (22)

Total BSD 38 (36.8) 35 (33.6) 33 (78.5) 106 (42.5)

BSD = biliary stone disease; CBD = common bile duct.


RECHERCHE


Biliary stone disease (including gallbladder stone, CBD stone, or both) more frequently existed in group 3 than in the other 2 groups (both p = 0.014). The biochemical values of bilirubin (total and conjugated), AST, ALT, GGT and ALP did not differ significantly among the groups. The CBD diameters and cannulation success of the CBD were also similar among the groups.

The median follow-up period was 61 (range 6–71) months. A total of 19 patients (7 in group 1, 9 patients in group 2, and 3 patients in group 3) were readmitted to the clinic because of different reports of pancreatobiliary origin. Only 6 patients underwent re-evaluation with ERCP (2 in group 1, 3 in group 2, and 1 in group 3). There was no recurrent stone disease in readmitted patients.

Discussion

Several studies on the association between JPDD and biliary stone disease have been performed. Most of these studies state that biliary stone disease is associated with JPDD. The pathological mechanism of this association is explained by several hypotheses. The mechanical pressure of the diveticu-lum to the distal end of the biliary tract is commonly dis-cussed. Another simple explanation is the dysfunction of the sphincter of Oddi (SO), which is believed to be caused by the accumulation of food in the diverticulum, putting pres-sure on the end of the bile duct and SO and leading to stric-ture of the sphincter. The dysfunction of the SO causes obstruction and stasis of bile juice. Additional reflux caused by contractional malfunction of the sphincter leads to the reflux of gastrointestinal juice into the bile duct, bacterial infection of the bile duct and formation of pigment bile duct stones.2,5–8 The dysfunction of the SO (decrease of the pres-sure) has been demonstrated in manometric studies.9,10 The clinical result of the dysfunction of SO is the formation of CBD stones, infection (cholangitis) or pancreatic disease.

We sought to investigate the clinical effect of different localizations of the papilla associated with JPDD and man-agement. We investigated whether the localization of the papilla was associated with JPDD, if this was important in the clinical presentation of JPDD, and what the therapeu-tic approach should be.

The reported incidence of biliary stone formation in patients with JPDD varies between 10% and 32%.3,11–15 In our series the incidence was 11.7%. Our patients had a median of age of 64.7 (range 29–85) years. It has been reported that DD is a disease of advanced age; the mean age of patients is reported to be 70–79 years in some series. It has been reported that the association with advanced age suggests a degenerative process involving local supporting structures as an additional factor in the pathogenesis of JPDD.3,11,13 We found no age difference among the groups.

The clinical presentation of JPDD is associated with biliary symptoms, including cholangitis, obstructive jaun-dice and pancreatitis.3,16–22

The clinical presentation of our patients was mostly associated with elevated bilirubin and other liver enzymes, including AST, ALT, GGT and ALP, with or without abdominal pain, fever and leucocytosis (obstruc-tive jaundice or cholangitis). It has been reported that patients with JPDD had less abdominal pain and more symptoms of biliary obstruction than patients without JPDD.3,16–22 The values of bilirubin (total and conju-gated), AST, ALT, GGT and ALP did not differ among the groups. Patients in groups 2 and 3 were more likely to be admitted with symptoms of obstructive jaundice. But, the existence of biliary stone disease among patients with obstructive jaundice was different among the groups. Patients in group 3 had biliary stones more frequently than those in other groups.

Cholangitis was commonly seen in group 1. Zoepf and colleagues3 reported that suppurative cholangitis was more frequent in patients with JPDD than in con-trol patients, but that this difference was not signifi-cant.3 They also claimed that the higher cholangitis rate associated with JPDD in their series was based only on the bile duct obstruction resulting from bile duct stones rather than on specific mechanisms associated with JPDD (e.g., ascending bacteria).2 In our series, however, cholangitis was more frequent in group 1, and these patients had biliary stone disease less frequently than those in the other groups. In contrast to Zoepf and col-leagues,3 we thought that the high cholangitis rate in group 1 should be associated with specific mechanisms associated with JPDD rather than bile duct obstruction resulting from bile duct stones. Furthermore, obstruc-tive jaundice was more commonly associated with biliary stone disease in group 3 patients. These 2 findings lead us to speculate that cholangitis and obstructive jaundice resulting from biliary obstruction were more commonly associated with stones in group 3 patients. Moreover, when the papilla is located closer to the JPDD, and even when the papilla is located inside it, cholangitis and obstructive jaundice become less frequently associated with the biliary stones.

There are some different reports about the develop-ment of pancreatitis in JPDD. Some investigators have suggested that pancreatitis is not associated with JPDD.3,23 Others reported that patients with DD have a higher rate of acute pancreatitis.24–26 The mechanism of pancreatitis in these patients is believed to be mainly of biliary origin. However, other investigators have sug-gested that JPDD is associated with acute idiopathic pan-creatitis and have postulated that DD is a risk factor for acute idiopathic pancreatitis, especially in elderly patients.26 In our series, pancreatitis existed in 29 (11.6%) patients. We are not able to discuss the association with pancreatitis because we did not include control patients in the study. However, when the existing patients were evaluated, the distribution was homogeneous among


RESEARCH


groups and there was no significant difference among the groups. We determined that the presence of biliary stone disease among patients presenting with pancreatitis differed significantly between groups 1 and 3 (p = 0.013) and groups 2 and 3 (p = 0.017). We think that this finding suggests that JPDD is associated with acute idiopathic pancreatitis and that DD is a risk factor for acute idio‑pathic pancreatitis, especially when the papilla is located close to the JPDD. We also think that pan‑creatitis is caused by specific mechanisms, as mentioned previously.

Boix and colleagues11 have proposed a classification of the localization of the papilla according to the JPDD. They reported that JPDD do not significantly increase the difficulty of deep cannulation. We had an overall cannu‑lation success rate of 87.5% at the first occurrence of ERCP. All patients were cannulated during the study for the first or second time. There was no statistical difference in cannulation success among the groups. We found that cannulation success did not depend on the localization of the papilla.

All of our patients underwent sphincterotomy. In our earli er paper, we stated that ES should be performed in the presence of biliary stone disease in group 3 patients.4 The present findings lead us to the same conclusion. Our findings showed that the biliopancreatic presentation of the JPDD depends on the existence of biliary stone disease in group 3 patients, and is partially independent from biliary stone dis‑ease in groups 1 and 2. Thus, we suggest ES in groups 1 and 2 even if there is no existing biliary stone disease. In group 3, ES should be performed according to the guidelines for bili‑ary stone disease independently from JPDD.

ConClusion

When the papilla is located close to the JPDD, the inci‑dence of biliary stone disease decreases, and pancreatobili‑ary diseases are caused mostly in the absence of biliary stone disease.Competing interests: None declared.

Contributors: B. Ozogul, G. Ozturk, B. Aydinli and S.S. Atamanalp designed the study. B. Ozogul, A. Kisaoglu and M. Yildirgan acquired the data, which B. Ozogul, G. Ozturk and A. Kisaoglu analyzed. B. Ozogul, G. Ozturk, A. Kisaoglu, B. Aydinli and S.S. Atamanalp wrote the article, which B. Ozogul and M. Yildirgan reviewed. All authors approved the final version for publication.

References

1. Adams DB. Management of the intraluminal duodenal diverticulum: endoscopy or duodenotomy. Amer J Surg 1986;151:524‑26.

2. Lobo DN, Balfour TW, Iftikhar SY, et al. Periampullary diverticula and pancreaticobiliary disease. Br J Surg 1999;86:588‑97.

3. Zoepf T, Zoepf DS, Arnold JC, et al. The relationship between jux‑tapapillary duodenal diverticulum and disorders of the biliopancratic system: analysis of 350 patients. Gastrointest Endosc 2001;54:56‑61.

4. Yildirgan MI, Basoglu M, Yilmaz I, et al. Periampullary diverticula causing pancreaticobiliary disease. Dig Dis Sci 2004;49:1943‑5.

5. van Nieuwkoop C, Boere I, Rosekrans PA, et al. Recurrent baterial cholangitis due to a juxtapapillary diverticulum. Eur J Gastroenterol Hepatol 2002;14:189‑90.

6. Chen WX, Zhang Y, Li YM, et al. Endoscopic retrograde cholan‑giopancreatography in evaluation of choledochal dilation in patients with obstructive jaundice. Hepatobiliary Pancreat Dis Int 2002;1:111‑3.

7. Ando T, Tsuyuguchi T, Okugawa T, et al. Risk factors for recurrent bile duct stones after endoscopic papillotomy. Gut 2003;52:116‑21.

8. Sugiyama M, Atomi Y. Periampullary diverticula cause pancreatobili‑ary reflux. Scand J Gastroenterol 2001;36:994‑7.

9. Lötveit T, Osnes M, Aune S. Bacteriological studies of common bile duct bile in patients with gallstone disease and juxtapapillary duo‑denal diverticula. Scand J Gastroenterol 1978;13:93‑5.

10. Løtveit T, Osnes M, Aune S, et al. Studies of the choledochoduo‑denal sphincter in patients with and without juxta‑papillary duodenal diverticula. Scand J Gastroenterol 1980;15:875‑80.

11. Boix J, Lorenzo‑Zúñiga V, Añaños F, et al. Impact of periampul‑lary duodenal diverticula at endoscopic retrograde cholangiopan‑creatography: a proposed classification of periampullary duodenal diverticula. Surg Laparosc Endosc Percutan Tech 2006;16:208‑11.

12. Vaira D, Dowsett JF, Hatfield ARW. Is duodenal diverticulum a risk factor for sphincterotomy? Gut 1989;30:939‑42.

13. Shemesh E, Klein E, Czerniak A. Endoscopic sphincterotomy in patients with gallbladder in situ: the influence of periampullary duo‑denal diverticula. Surgery 1990;107:163‑6.

14. Wu SD, Su Y, Fan Y, et al. Relationship between intraduodenal peri‑ampullary diverticulum and biliary disease in 178 patients undergoing ERCP. Hepatobiliary Pancreat Dis Int 2007;6:299‑302.

15. Christoforidis E, Goulimaris I, Kanellos I, et al. The role of juxta‑papillary duodenal diverticula in biliary stone disease. Gastrointest Endosc 2002;55:543‑7.

16. Vassilakis JS, Tzovaras G, Chrysos E, et al. Roux‑Y choledochojeju‑nostomy and duodenojejunostomy for the complicated duodenal diverticulum. Am J Surg 1997;174:45‑8.

17. Castilho Netto JM, Speranzini MB. Ampullary duodenal diverticu‑lum and cholangitis. Sao Paulo Med J 2003;121:173‑5.

18. Miyazaki S, Sakamoto T, Miyata M, et al. Function of the sphincter of Oddi in patients with juxtapapillary duodenal diverticula: evalua‑tion by intraoperative biliary manometry under a duodenal pressure load. World J Surg 1995;19:307‑12.

19. Kubota K, Itoh T, Shibayama K, et al. Papillary function of patients with juxtapapillary duodenal diverticulum. Consideration of patho‑genesis of common bile duct stones. Scand J Gastroenterol 1989; 24:140‑4.

20. Ponce J, Garrigues V, Sala T, et al. Motor pattern of the sphincter of Oddi in patients with juxtapapillary diverticula. J Clin Gastroenterol 1990;12:162‑5.

21. Skar V, Skar G, Osnes M. The duodenal bacterial flora in the region of papilla of Vater in patients with and without duodenal diverticula. Scand J Gastroenterol 1989;24:649‑56.

22. Skar V, Skar AG, Bratlie J, et al. Beta‑glucuronidase activity in the bile of gallstone patients both with and without duodenal diverticula. Scand J Gastroenterol 1989;24:205‑12.

23. van Basten JP, Stockbrügger R. Relationship between duodenal diverticuli, gallstones and duodenal and pancreaticobiliary disorders. Ned Tijdschr Geneeskd 1996;140:1122‑5.

24. Løtveit T, Skar V, Osnes M. Juxtapapillary duodenal diverticula. Endoscopy 1988;20:175‑8.

25. Leivonen MK, Halttunen JAA, Kivilaakso EO. Duodenal diverticu‑lum at endoscopic retrograde cholangiopancreatography, analysis of 123 patients. Hepatogastroenterology 1996;43:961‑6.

26. Uomo G, Manes G, Ragozzino A, et al. Periampullary extraluminal duodenal diverticula and acute pancreatitis: an underestimated etio‑logical association. Am J Gastroenterol 1996;91:1186‑8.




Factors affecting transfusion requirement after hip fracture: Can we reduce the need for blood?

Background: Hip fractures are common injuries that result in blood loss and fre-quently require the transfusion of blood products. We sought to identify risk factors leading to increased blood transfusion in patients presenting with hip fractures, espe-cially those factors that are modifiable.

Methods: We retrospectively reviewed the cases of all patients who had fixation of their hip fractures between October 2005 and February 2010. The need for transfu-sion was correlated with potential risk factors, including age, sex, preoperative hemo-globin, fracture type, fixation method and more.

Results: A total of 835 patients had fixation of their hip fractures during the study period; 631 met the inclusion criteria and 249 of them (39.5%) were transfused. We found an association between need for blood transfusion and female sex (p = 0.018), lower preoperative hemoglobin (p < 0.001), fracture type (p < 0.001) and fixation method (p < 0.001). Compared with femoral neck fractures, there was a 2.37 times greater risk of blood transfusion in patients with intertrochanteric fractures (p < 0.001) and a 4.03 times greater risk in those with subtrochanteric fractures (p < 0.001). Dynamic hip screw (DHS) fixation decreased the risk of transfusion by about half com-pared with intramedullary nail or hemiarthroplasty. We found no association with age, delay to operation (p = 0.17) or duration of surgery (p = 0.30).

Conclusion: The only modifiable risk factor identified was fixation method. When con-sidering blood transfusion requirements in isolation, we suggest a potential benefit in using a DHS for intertrochanteric and femoral neck fractures amenable to DHS fixation.

Contexte : La fracture de la hanche est un traumatisme fréquent, qui cause une perte san-guine et nécessite souvent la transfusion de produits sanguins. Nous avons tenté d’identifier les facteurs de risque associés à une hausse du nombre des transfusions sanguines chez des patients ayant subi une fracture de la hanche, en particulier les facteurs modifiables.

Méthodes : Au cours d’une étude rétrospective, on a revu les cas de tous les patients chez qui on avait pratiqué une ostéosynthèse pour une fracture de la hanche survenue entre octobre 2005 et février 2010. La nécessité d’une transfusion sanguine a été asso-ciée à d’éventuels facteurs de risque, dont l’âge, le sexe, le taux d’hémoglobine préopéra-toire, le type de fracture, la technique d’ostéosynthèse, et d’autres facteurs encore.

Résultats : Au total, 835 patients avaient subi une ostéosynthèse pour fracture de la hanche au cours de la période à l’étude; 631 satisfaisaient les critères d’inclusion à l’étude et parmi eux, 249 (39,5 %) ont reçu une transfusion sanguine. On a observé l’existence d’un lien entre la nécessité d’une transfusion sanguine et le sexe féminin (p = 0,018), une plus faible concentration d’hémoglobine préopératoire (p < 0,001), le type de fracture (p < 0,001) et la technique d’ostéosynthèse (p < 0,001). Par rapport aux fractures du col fémoral, le ris-que de transfusion sanguine était 2,37 fois plus élevé chez les patients présentant une frac-ture intertrochantérienne (p < 0,001) et 4,03 fois plus élevé chez ceux présentant une frac-ture sous-trochantérienne (p < 0,001). En utilisant une vis dynamique de hanche, le risque de transfusion sanguine a diminué d’environ 50 % par rapport à l’enclouage centromédul-laire ou à l’hémiarthroplastie. Aucun lien n’a été observé avec l’âge, le délai de l’intervention chirurgicale (p = 0,17), ni avec sa durée (p = 0,30).

Conclusion : La technique d’ostéosynthèse est l’unique facteur de risque modifiable ayant été identifié. Mais lorsqu’on évalue la nécessité d’une transfusion sanguine sans tenir compte des facteurs de risque, nos résultats semblent indiquer qu’on aurait avan-tage à utiliser une vis dynamique de hanche pour consolider les fractures intertrochanté-riennes et les fractures du col fémoral.

Sagar J. Desai, MD Kristi S. Wood, MSc, MD Jackie Marsh, MSc, PhD Dianne Bryant, MSc, PhD Hussein Abdo, BSc Abdel-Rahman Lawendy, MSc, MD David W. Sanders, MD, MSc

From Western University, London, Ont.


Correspondence to: S.J. Desai Chief Resident, Orthopaedic Surgery St. Joseph’s Health Centre 268 Grosvenor St., Rm D0-213 London ON N6A 4L6 [email protected]

DOI: 10.1503/cjs.030413

factors-desai.indd 342 14-09-16 10:58 AM

RESEARCH


H ip fractures are among the most common fractures treated by orthopedic surgeons. With increasing life expectancy, it is estimated that the number of people

aged 65 and older will increase from the recent estimate of 323 million to 1555 million by the year 2050. As a result, it is estimated that the number of hip fractures occurring worldwide will increase from 1.66 million in 1990 to 6.26 mil lion in 2050.1

Hip fractures result in blood loss and frequently require the transfusion of blood products. While blood transfusions are potentially life-saving interventions, they can also cause patient morbidity. Blood transfusions are correlated with an increased risk of bacterial infections2–7 and possibly increased mortality.8,9 There are also substantial costs involved in the collection, preparation, transport and administration of blood.

In the United States, more than 15 million units of blood are transfused annually.10 Many of these transfusions are given to surgical patients, including elderly patients with hip fractures. We sought to determine whether any modifiable risk factors for transfusion exist. The purpose of this study, therefore, was to assess risk factors for blood transfusion requirements in patients presenting with hip fractures. We performed a retrospective study at a single level I trauma centre from 2005 to 2010. Blood transfusion requirements were correlated with patient variables, such as age, sex, delay to surgery, duration of surgery, preopera-tive hemoglobin, fracture type and fixation method.

Methods

All patients undergoing surgical fixation of their hip frac-tures in a single academic trauma centre between October 2005 and February 2010 were included in this retrospective study. The fracture patterns included were femoral neck, intertrochanteric and subtrochanteric fractures. Fixation methods used included hemiarthroplasty, dynamic hip screw (DHS), cannulated screws and cephalomedullary nails. The study was approved by our institution’s review board. All patient information, including laboratory values and operative notes, were collected from our institution’s electronic patient database, Powerchart (Cerner Corpora-tion). Blood transfusion information was collected from our institution’s blood transfusion laboratory.

The type of hip fracture was documented based on review of patients’ preoperative and postoperative radio-graphs. These included femoral neck fractures (AO-OTA 31-B1–3), intertrochanteric fractures (AO-OTA 31-A1–3) and subtrochanteric fractures (AO-OTA 32A,1–3 32-B[1–3] and 32-C[1–3]). Surgical fixation was documented based on review of patients’ preoperative and postoperative radio-graphs. The DHS used was from Synthes. All hemiarthro-plasties were performed with the Conquest system (Smith & Nephew) through a standard Hardinge ap proach. The intramedullary nails were either Trigen or Intertan (both from Smith & Nephew). The cannulated screws were 7.3-

mm screws (Synthes Inc). The following measures were recorded from the patients’ electronic charts: sex; age; American Society of Anesthesiologist (ASA) score; duration of surgery; and need for preoperative, intraoperative and postoperative blood transfusion. Time from admission to operation was also documented and was defined as the time from admission to our institution’s emergency department to the start of the operation. Criteria for administration of blood transfusion were a hemoglobin value less than 70 g/L or less than 80 g/L with signs/symptoms of anemia.

Patients were excluded from this study if they were younger than 60 years; had a known cancer in the region of the fracture; had a hemorrhagic complication in another ana-tomic site, such as a gastrointestinal bleed, pre- or postopera-tively; were admitted to hospital for other clinically important comorbidities, such as sepsis or polytrauma; were undergoing revision surgery; had an intraoperative complication, such as a trochanteric fracture; were therapeutically anticoagulated or had documented hematologic disease before surgery; or had a delay in diagnosis of their fracture longer than 1 week.

Notably, all patients received thromboembolic prophy-laxis with 5000 units of low molecular-weight heparin (dalte-parin sodium, Pfizer Canada). This therapy was started on admission, withheld on the day of surgery and restarted on the first postoperative day.


We performed our statistical analyses using SPSS software. We conducted a univariate analysis of all independent vari-ables (i.e., age, sex, duration of surgery, preoperative hemo-globin level, fracture type, fixation method) to establish an association with blood transfusion requirement. Variables that were found to have a significant association were then included in a multivariate analysis. We considered results to be significant at p < 0.05.

Results

A total of 835 patients had fixation of their hip fractures during the study period; 631 patients met the inclusion cri-teria (Fig. 1). Forty-one patients were excluded because of multiple injuries, 73 patients were anticoagulated, 32 had pathologic or pending pathologic fractures, 23 had a signifi-cant hemorrhagic complication unrelated to their hip frac-ture, 16 underwent revision surgery, 9 experienced an intra-operative complication, 4 were excluded because of poor documentation and 6 were delayed to surgery because the fracture diagnosis was delayed longer than 1 week (Fig. 1).

The mean age was 81.6 (range 60–100) years. The sam-ple comprised 455 women (72.1%, mean age 82.4 yr) and 176 men (27.9%, mean age 79.3 yr; Table 1). The mean delay from admission to surgery was 48.9 hours. Of the 631 patients in the study, 249 patients were transfused (39.5%). This group included 26% of patients with femoral


RECHERCHE


Table 1. Characteristics of study participants

Characteristic No. (%),* n = 618

Age, mean ± SD yr 81.6 ± 8.7

Sex, female 444 (71.8)

Delay to OR in h

mean ± SD 48.9 ± 33.4

median (IQR) 43.3 (26.1–63.2)

Duration of surgery, mean ± SD min 63.3 ± 23.8

Preoperative hemoglobin, mean ± SD

118.8 ± 16.0

Fracture type

Femoral neck 318 (51.5)

Intertrochanteric 254 (41.1)

Subtrochanteric 44 (7.1)

Fixation type

Hemiarthroplasty 262 (42.4)

DHS 246 (39.8)

IM nail 108 (17.5)

Fracture by fixation

Femoral neck — hemiarthroplasty 262 (42.5)

Femoral neck — DHS 56 (9.1)

Intertrochanteric — DHS 190 (30.8)

Intertrochanteric — IM nail 64 (10.4)

Subtrochanteric — IM nail 44 (7.1)

DHS = dynamic hip screw; IM = intramedullary; IQR = interquartile range; OR = operating room; SD = standard deviation. *Unless otherwise indicated.

Fig. 1. Patients meeting inclusion criteria. Cann screws = cannulated screws; DHS = dynamic hip screw; hemi = hemiarthroplasty; intertroch = intertrochanteric fracture; nail = intramedul-lary nail; subtroch = subtrochanteric fracture.

Total, n = 835

Eligible, n = 631

Nail, n = 46

Subtroch, n = 46 Intertroch, n = 252

Excluded, n = 204• Polytrauma, n = 42 • Coumadin, n = 73 • Comorbidity, n = 23 • Pathologic, n = 32 • Revision, n = 16 • Intraoperative complications,

n = 9 • Poor records, n = 4 • Missed fractures, n = 6

Femoral neck, n = 333

DHS, n = 56Cann screws, n = 13

Hemi, n = 264

Nail, n = 64 DHS, n = 188


RESEARCH


neck fractures, 52% with intertrochanteric fractures and 71% with subtrochanteric fractures. The majority of blood transfusions were administered on postoperative day 1, 2 or 3 (Fig. 2).

The results of the univariate analysis are presented in Table 2. The 13 patients with femoral neck fractures treated with cannulated screws were removed from the analysis because of the small number of patients. The univariate an alysis demonstrated an association between need for blood transfusion and increased age (p = 0.004), female sex (p =

0.018), lower preoperative hemoglobin level (p < 0.001), frac-ture type (p < 0.001) and fixation method (p < 0.001). Patients requiring a blood transfusion had an average ASA score of 3.4, whereas patients not receiving a transfusion had an aver-age score of 3.3 (p < 0.001). We found no association with delay to operation (p = 0.17) or duration of surgery (p = 0.30).

Multivariate analysis demonstrated an association between blood transfusion requirement and 3 variables (Table 3). Men were at half the risk of women (1.54 odds ratio [OR], 95% confidence interval [CI] 1.002–2.36,

Table 2. Univariate logistic regression analyses to predict transfusion, n = 618

Potential predictor OR (95% CI) p value

Age, 5-yr increase 1.16 (1.05–1.28) 0.004

Sex, women v. men 1.61 (1.08–2.38) 0.018

Delay to operating room, 8-h increase 0.97 (0.93–1.01) 0.17

Duration of surgery, 5-min increase 0.98 (0.95–1.02) 0.30

Preoperative hemoglobin, 10-point increase 0.65 (0.58–0.73) < 0.001

Fracture type < 0.001

Intertrochanteric v. femoral neck 2.37 (1.65–3.39)

Subtrochanteric v. femoral neck 4.03 (2.11–7.70)

Fracture by fixation < 0.001

Femoral neck, DHS v. hemiarthroplasty 0.51 (0.23–1.12)

Intertrochanteric, DHS v. intramedullary nail 0.57 (0.32–1.02)

CI = confidence interval; DHS = dynamic hip screw; OR = odds ratio.

Table 3. Multivariable analyses to predict transfusion. Logistic regression with only those variables that were significant at p = 0.05 in univariate analyses, n = 618

Potential predictor Adjusted OR (95% CI) p value

Age, 5-yr increase 1.06 (0.95–1.19) 0.27

Sex, women v. men 1.54 (1.002–2.36) 0.049

Preoperative hemoglobin, 10-point increase 0.69 (0.61–0.78) < 0.001

Fracture, fixation < 0.001

Femoral neck, DHS v. hemiarthroplasty 0.49 (0.21–1.12)

Intertrochanteric, DHS v. intramedullary nail 0.52 (0.29–0.95)

CI = confidence interval; DHS = dynamic hip screw; OR = odds ratio.

Fig. 2. Number of patients receiving blood transfusions preoperatively, intraoperatively and postoperatively. Most transfusions were performed on postoperative day 1, 2 or 3. OR = intra-operative transfusion; preop 0 = preoperative transfusion day of surgery; postop 0 = postoper-ative transfusion day of surgery.

0

10

20

30

40

50

60

4 3 2 1 0 OR 0 1 2 3 4 5 6 7

No.

of t

rans

fusi

ons

Preop Postop


RECHERCHE


p = 0.049). For every 10 g/L increase in preoperative hemoglobin, the risk of transfusion decreased by about 30% (OR 0.69, 95% CI 0.61–0.78, p < 0.001). Femoral neck fractures treated with DHS reduced the risk of trans-fusion by half compared with hemiarthroplasty (OR 0.49, 95% CI 0.61–0.78), and intertrochanteric fractures treated with DHS reduced the risk of transfusion by half com-pared with intramedullary nail (OR 0.52, 95% CI 0.29–0.95). This indicates that DHS fixation in either femoral neck fractures or intertrochanteric fractures decreases the risk of transfusion by about half compared with treatment with an intramedullary nail or hemiarthroplasty.

Discussion

We found a correlation between blood transfusion requirement and sex, preoperative hemoglobin, ASA score, fracture type and fixation method. No correlation was found with age, duration of surgery or delay from admis-sion to operation.

Low preoperative hemoglobin is an independent risk factor for the need for blood transfusion. In the present study, preop-erative hemoglobin was 112.0 ± 14.3 g/L in transfused patients and 122.1 ± 15.8 g/L in those not transfused (p < 0.001). Multi variate analysis showed that for every 10 g/L decrease in hemoglobin, patients had a 30% increased risk of blood trans-fusion (p < 0.001). This is consistent with a study by Adunsky and colleagues,11 who studied blood transfusion patterns in 302 patients with hip fractures. They found that a hemoglobin value less than 12 g/dL (120 g/L) increased transfusion risk 5-fold. They suggested that patients with a hemoglobin greater than 12 g/dL (120 g/L) did not require crossmatching preoperatively. Other studies have also identified low preoper-ative hemoglobin as a risk factor for transfusion.12–15

Our univariate analysis showed that older patients were more likely to receive a blood transfusion, but age was not important in our multivariate analysis, which suggests that other factors explain the same variability in need for trans-fusion as age but were even more predictive. The average age of patients in our study who received a blood transfu-sion was 83.1 ± 7.9 years compared with 80.9 ± 9.0 years in patients who did not (p < 0.003). Swain and colleagues16 studied the transfusion requirements for 249 patients with femoral neck fractures and found that patients aged 80 years and older were transfused significantly more than those aged younger than 80 years. Similarly, Dillon and colleagues12 found that patients older than 75 years were at higher risk of receiving blood transfusion.

Patients receiving a blood transfusion had an average ASA score of 3.4 compared with 3.3 in patients who did not receive a transfusion (p < 0.001). This result was signif-icant; however, it is difficult to determine the clinical sig-nificance with such a minor difference between scores (0.1). Previous studies examining ASA scores and transfu-sion requirements did not find any association.11,12

Delay from admission to operation in elderly patients with hip fractures carries significant morbidity and mortal-ity. Delay from admission to operation has been shown to increase mortality,17–19 postoperative infections19,20 and length of stay in hospital.20–22 However, the present study did not find a correlation with delay to operation and transfusion requirements. One would assume that while a patient is awaiting surgery, continued blood loss would be present at the fracture site, leading to greater blood loss and greater risk of transfusion. The equivocal risk of trans-fusion found in our study may be related to the formation of hematoma around the fracture site. The delay to surgery may have allowed the fracture hematoma to fully stabilize, minimizing the active bleeding before surgery. Intraopera-tively, this may have resulted in less surgical blood loss and a lower rate of blood transfusion.

When comparing fracture types, patients with intertro-chanteric or subtrochanteric fractures were at an increased risk of requiring a blood transfusion. When compared with femoral neck fractures, there was a 2.37 times greater risk of blood transfusion in patients with an intertrochan-teric fracture (p < 0.001) and a 4.03 times greater risk in patients with a subtrochanteric fracture (p < 0.001). These results are consistent with those of Adunsky and col-leagues,11 who found that patients with pertrochanteric fractures were transfused significantly more than patients with subcapital fractures. Swain and colleagues16 also found an increased transfusion requirement in patients with intertrochanteric fractures compared with those with intracapsular fractures, and Dillon and colleagues12 reported an increased risk for blood transfusion in patients with pertrochanteric fractures.

When comparing fixation methods for the different fracture types, we found a significant difference in blood transfusion requirements. In patients with femoral neck fractures, 24.8% treated with hemiarthroplasty were transfused compared with 14.3% of patients treated with DHS (p < 0.001). This may be partially related to severity of injury, as the more displaced fractures were likely treated with hemiarthroplasty. This finding is consistent with those of a meta-analysis performed by Wang and col-leagues,23 who compared the outcomes of patients who underwent arthroplasty with those of patients who under-went internal fixation for displaced femoral neck fractures. They found greater operative blood loss and increased transfusion requirement in the hemiarthroplasty group. Similarly, Parker and colleagues24 found lower operative blood loss and lower transfusion requirements with inter-nal fixation (using cannulated screws) than with hemi-arthroplasty in patients with displaced femoral neck frac-tures. Similar to femoral neck fractures, intertrochanteric fractures treated with a DHS had a lower risk of transfu-sion than those treated with an intramedullary device. In our study, 37.9% of intertrochanteric fractures treated with a DHS were transfused compared with 51.6%


RESEARCH


treated with an intramedullary device (p < 0.001). The literature comparing blood loss in intertrochanteric hip fractures treated with intramedullary nail or DHS is inconclusive. Authors have reported reduced blood loss,25–27 increased blood loss28 and no difference29,30 in patients with intertrochanteric fractures treated with an intramedullary nail. The variability among studies may be related to differences in fracture severity, as patients with more displaced fractures are generally more likely to be treated with an intramedullary device.

Limitations

There are limitations to this study that should be considered. First, there may be inherent differences in medical comorbidities between the transfused and nontransfused patient samples that were not discerned by this retrospective, observational study. As mentioned, we attempted to stratify by ASA score, but it is difficult to determine if such a small difference in ASA score between groups has any clinical importance. Second, patients were generally given a transfusion based on the criteria of hemoglobin less than 70 g/L or less than 80 g/L with signs/symptoms of anemia. This threshold is consistent with the restrictive strategy group in a study by Carson and colleagues,31 who compared restricted and liberal transfusion thresholds. Similar to Carson and colleagues,31 we attempted to make the decision to transfuse as uniform as possible; however, there are difficulties with this. Determining signs/symptoms of anemia is subjective, and a lack of uniformity inherently exists among treating physicians. This may have resulted in some inconsistencies in decision to transfuse. Finally, we did not separately analyze patients with stable and unstable intertrochanteric fractures. One would assume that 3 and 4part intertrochanteric fractures are most likely to cause greater blood loss and more likely to be treated with an intramedullary device. This would potentially affect the results of transfusion requirements between the intramedullary nail and DHS groups. However, previously published literature has failed to find convincing evidence of greater blood loss in patients with unstable fracture patterns.32,33

ConClusion

We found a correlation with blood transfusion requirement and sex, preoperative hemoglobin, fracture type and fixation method. The only modifiable risk factor found in the present study was fixation method. Further studies would be beneficial to determine other potential modifiable risk factors. Based on our findings, when considering blood transfusion requirements in isolation, we suggest a potential benefit in using a DHS for intertrochanteric and femoral neck fractures amenable to DHS fixation.


Contributors: S. Desai, D. Bryant, A. Lawendy and D.W. Sanders designed the study. S. Desai, K.S. Wood and H. Abdo acquired the data, which S. Desai, J. Marsh, D. Bryant and A. Lawendy analyzed. S. Desai wrote the article, which all authors reviewed and approved for publication.

References

1. Dennison E, Mohamed MA, Cooper C. Epidemiology of osteoporosis. Rheum Dis Clin North Am 2006;32:61729.

2. Carson JL, Altman DG, Duff A, et al. Risk of bacterial infection associated with allogeneic blood transfusion among patients undergoing hip fracture repair. Transfusion 1999;39:694700.

3. Agarwal N, Murphy JG, Cayten CG, et al. Blood transfusion increases the risk of infection after trauma. Arch Surg 1993;128:1716, discussion 1767.

4. Edna TH, Bjerkeset T. Association between blood transfusion and infection in injured patients. J Trauma 1992;33:65961.

5. Edna TH, Bjerkeset T. Association between transfusion of stored blood and infective bacterial complications after resection for colorectal cancer. Eur J Surg 1998;164:44956.

6. Hill GE, Frawley WH, Griffith KE, et al. Allogeneic blood transfusion increases the risk of postoperative bacterial infection: a metaanalysis. J Trauma 2003;54:90814.

7. Koval KJ, Rosenberg AD, Zuckerman JD, et al. Does blood transfusion increase the risk of infection after hip fracture? J Orthop Trauma 1997;11:2605, discussion 2656.

8. Engoren M, Mitchell E, Perring P, et al. The effect of erythrocyte blood transfusion on survival after surgery for hip fracture. J Trauma 2008;65:14115.

9. Vincent JL, Baron JF, Reinhart K, et al. Anemia and blood transfusion in critically ill patients. JAMA 2002;288:1499507.

10. Report from Department of Health and Human Services. The 2009 National Blood Collection And Utilization Survey Report. Washington (DC): Department of Health and Human Services, Office of the Assistant Secretary for Health; 2011.

11. Adunsky A, Lichtenstein A, Mizrahi E, et al. Blood transfusion requirements in elderly hip fracture patients. Arch Gerontol Geriatr 2003;36:7581.

12. Dillon MF, Collins MB, Rice J, et al. Preoperative characteristics identifying patients with hip fractures at risk of transfusion. Clin Orthop Relat Res 2005; (439):2016.

13. Kurdy NM, Hokan R. A crossmathing policy for fractures of the proximal third of the femur. Injury 1993;24:5214.

14. Levi N. Blood transfusion requirements in intracapsular femoral neck fractures. Injury 1997;27:70911.

15. Robbins J, Steingold RF. Blood use in urgent operation for patients with fractures of the femoral neck. Injury 1986;17:2656.

16. Swain DG, Nightingale PG, Patel JV. Blood transfusion requirements in femoral neck fracture. Injury 2000;31:710.

17. Zuckerman JD, Skovron ML, Koval KJ, et al. Postoperative complications and mortality associated with operative delay in older patients who have a fracture of the hip. J Bone Joint Surg Am 1995;77:15516.

18. Moran CG, Wenn RT, Sikand M, et al. Early mortality after hip fracture: Is delay before surgery important? J Bone Joint Surg Am 2005;87:4839.

19. Simunovic N, Devereaux PJ, Sprague S, et al. Effect of early surgery after hip fracture on mortality and complications: systematic review and metaanalysis. CMAJ 2010;182:160916.

20. Verbeek DO, Ponsen KJ, Goslings JC, et al. Effect of surgical delay on outcome in hip fracture patients: a retrospective multivariate analysis of 192 patients. Int Orthop 2008;32:138.

21. Rogers FB, Shackford SR, Keller MS. Early fixation reduces morbidity and mortality in elderly patients with hip fractures from


RECHERCHE


low-impact falls. J Trauma 1995;39:261-5.22. Orosz GM, Magaziner J, Hannan EL, et al. Association of timing of

surgery for hip fracture and patient outcomes. JAMA 2004; 291:1738-43.

23. Wang J, Jiang B, Marshall RJ, et al. Arthroplasty of internal fixation for displaced femoral neck fractures: Which is the optimal alternative for elderly patients? A meta-analysis. Int Orthop 2009;33:1179-87.

24. Parker MJ, Khan JK, Crawford J, et al. Hemiarthroplasty versus internal fixation for displaced intracapsular hip fractures in the elderly. J Bone Joint Surg Br 2002;84:1150-5.

25. Giancola R, Antonini G, Rose GD, et al. Percutaneous compression plating versus gamma nail for the treatment of pertrochanteric hip fractures. Strategies Trauma Limb Reconstr 2008;3:9-14.

26. Dujardin FH, Benewz C, Polle G, et al. Prospective randomized comparison between a dynamic hip screw and a mini-invasive static nail in fractures of the trochanteric area: preliminary results. J Orthop Trauma 2001;15:401-6.

27. Little NJ, Verma V, Fernando C, et al. A prospective trial compar-ing the Holland nail with the dynamic hip screw in the treatment of intertrochanteric fractures of the hip. J Bone Joint Surg Br 2008; 90:1073-8.

28. Foulongne E, Gilleron M, Roussignol X, et al. Mini-invasive nail versus DHS to fix pertrochanteric fractures: a case-control study. Orthop Traumatol Surg Res. 2009;95:592-8.

29. Varela-Egocheaga JR, Iglesias-Colao R, Suarez-Suarez MA, et al. Minimally invasive osteosynthesis in stable trochanteric fractures: a comparative study between Gotfried percutaneous compression plate and gamma 3 intramedullary nail. Arch Orthop Trauma Surg 2009;129:1401-7.

30. Harrington P, Nihal A, Singhania AK, et al. Intramedullary hip screw versus sliding hip screw for unstable intertrochanteric femor al fractures in the elderly. Injury 2002;33:23-8.

31. Carson JL, Terrin ML, Noveck H, et al. Liberal or restrictive transfusion in high-risk patients after hip surgery. N Engl J Med 2011;365:2453-62.

32. Lavini F, Renzi-Brivio L, Aulisa R, et al. The treatment of stable and unstable proximal femoral fractures with a new trochanteric nail: results of a multicentre study with the Veronail. Strategies Trauma Limb Reconstr 2008;3:15-22.

33. Leung KS, So WS, Shen WY, et al. Gamma nails and dynamic hip screws for peritrochanteric fractures. A randomised prospective study in elderly patients. J Bone Joint Surg Br 1992;74:345-51.

Essential reading from the Canadian Medical Association

• CMAJ• Canadian Journal of Surgery• Journal of Psychiatry & Neuroscience

For information contactCMA Member Service Centre888 [email protected]

Does ultrasonography accurately diagnose acute cholecystitis?

Improving diagnostic accuracy

Minimally displaced clavicle fracture after high-energy injury:

Are they likely to displace?Intraoperative systemic lidocaine for pre-emptive analgesics in

subtotal gastrectomy: a prospective, randomized, double-blind

placebo-controlled studyThe impact of an acute care surgery clinical care pathway

for suspected appendicitis on the use of CT in the EDSPONSORS

Canadian Association of General Surgeons

Canadian Society for Vascular Surgery

Canadian Society of Surgical Oncology

Canadian Association of Thoracic Surgeons

Department of Surgery, Western University

Department of Surgery, University of Alberta

Department of Surgery, University of Calgary

Département de chirurgie, Université de Sherbrooke

Department of Surgery, McMaster University

Département de chirurgie, Université de Montréal

Vol. 57, No. 3, June/juin 2014canjsurg.ca

September 2014 Volume 39 Number 5

Zinc finger protein 804A (ZNF804A) and verbal deficits

in individuals with autism

MicroRNA-137 regulates a glucocorticoid receptor–

dependent signalling network: implications for the

etiology of schizophrenia

Do reward-processing deficits in schizophrenia-spectrum

disorders promote cannabis use? An investigation of

physiological response to natural rewards and drug cues

jpn.ca

An open-access journal

V

ol. 39, No. 5 P

ages 289-360

September 2014

Journ

al of Psych

iatry & N

euroscien

ce

.




Emergency surgery for colorectal cancer does not result in nodal understaging compared with elective surgery

Background: It has been suggested that inadequate lymph node harvest may result in pathologically understaged or indeterminate staging of patients with colorectal can-cer (CRC). We compared the adequacy of nodal staging in patients undergoing emer-gency surgery compared with elective surgery for CRC.

Methods: Using a prospectively collected CRC surgery database at a tertiary care centre, we performed a cohort study. The mean number of lymph nodes harvested and the proportion of patients who had inadequate staging (< 12 nodes harvested) were compared between emergency and elective surgery cohorts. Our analysis was adjusted for tumour site, type of resection, surgical training and pathologic stage.

Results: A total of 1279 of 1356 (94%) enrolled patients had nodal data available for an aly sis; 161 (13%) patients had emergency surgery and 1118 (87%) had elective sur-gery. The mean number of nodes removed was higher in the emergency surgery group (mean difference +2.8, 95% confidence interval [CI] 0.6–5.1, p = 0.012). The propor-tion of patients with inadequate nodal staging did not differ between groups (emergent 16%, elective 17%, p = 0.79). The odds of adequate nodal staging, adjusting for site, type of resection, training and stage was no different between groups (OR 0.80, 95% CI 0.47–1.35, p = 0.41).

Conclusion: The evidence does not support the common belief that emergency sur-gery is more commonly understaged in CRC. Our data suggest emergency surgery resulted in a significant increase in the average number of nodes harvested, with no difference in inadequate nodal staging.

Contexte : Il semble qu’une méthode erronée de prélèvement de lymphonœuds pour-rait expliquer pourquoi le stade d’évolution du cancer colorectal (CCR) est sous-évalué ou qu’il est impossible de le déterminer chez certains patients. On a comparé la méthode de détermination de l’atteinte des lymphonœuds chez des patients atteints d’un CCR devant subir une chirurgie d’urgence à celle utilisée chez des patients devant subir une chirurgie non urgente.

Méthodes : En utilisant une base de données prospectives sur des chirurgies du côlon pratiquées dans un établissement de soins tertiaires, on a comparé le nombre moyen de prélèvements de lymphonœuds et la proportion de patients pour lesquels le stade d’évolution était erroné (prélèvement de < 12 lymphonœuds) entre la cohorte de patients ayant subi une chirurgie d’urgence et celle ayant subi une chirurgie non urgente. Les résultats de notre analyse ont été ajustés en fonction du siège des tumeurs, du type de résection, de la formation chirurgicale et du stade pathologique.

Résultats : Pour 1279 (94 %) des 1356 patients recrutés, on disposait des données sur les lymphonœuds; 161 patients (13 %) avaient subi une chirurgie d’urgence et 1118 (87 %), une chirurgie non urgente. Le nombre moyen de lymphonœuds prélevés était plus élevé pour le groupe de patients ayant subi une chirurgie d’urgence (écart moyen +2,8, intervalle de confiance [IC] à 95 % 0,6–5,1, p = 0,012). Mais la proportion de patients pour lesquels le stade d’évolution de la maladie était erroné ne différait pas entre les groupes (intervention d’urgence 16 %, intervention non urgente 17 %, p = 0,79). La probabilité que le stade d’évolution soit exact, l’ajustement en fonction du siège des tumeurs, du type de résection, de la formation chirurgicale et du stade d’évolution ne dif-féraient pas entre les groupes (RR 0,80, IC à 95 % 0,47–1,35, p = 0,41).

Conclusion : Les résultats de notre étude ne confirment pas la croyance répandue selon laquelle le stade d’évolution du CCR est plus souvent sous-évalué chez les patients ayant subi une chirurgie d’urgence. En effet, nos données semblent indiquer que les chirurgies d’urgence étaient associées à un nombre plus élevé de lym-phonœuds prélevés, mais qu’il n’y avait aucune différence pour ce qui est des erreurs de détermination du degré d’atteinte des lymphonœuds.

Sunil Vijay Patel, MD, MSc* Sanjay Vijay Bharat Patel, MB, BCh, BAO* Muriel Brackstone, MD, PhD*†

From the *Department of Surgery, †Department of Oncology, Schulich School of Medicine & Dentistry, Western University, London, Ont.

Poster presented at Canadian Surgery Forum 2013, Sept. 19–22; Ottawa, Ont.


Correspondence to: S.V. Patel General Surgery London Health Sciences Centre University Hospital 339 Windermere Road P.O. Box 5339 London ON N6A 5A5 [email protected]

DOI: 10.1503/cjs.019313

emerg-patel.indd 349 14-09-16 10:59 AM

RECHERCHE


C olorectal cancer (CRC) is the fourth most common cancer in Canada and accounts for the second most cancer-related deaths. An estimated 23 300 Canad-

ians received diagnoses of CRC in 2012, with 9200 suc-cumbing to the disease.1 The accepted management of CRC is complete resection, surgical dissection of the asso-ciated lymph node basin and removal of any contiguous organs involved. The common occurrence of CRC and the emphasis of early surgical intervention indicates that man-agement of this disease is, and will remain, a significant part of general surgical practice.

Adjuvant chemotherapy has shown clear improvement in survival and lower recurrence rates in node-positive or stage III disease.2 Adjuvant chemotherapy with fluorouracil plus leucovorin or capecitabine-based regimes is now the standard of care for treatment of stage III disease.3,4 Although some advocate for adjuvant therapy in stage II disease, the evidence is less clear.5 A significant improve-ment in survival with adjuvant chemotherapy in stage II disease has been elusive, although there may be some ben-efit in high-risk populations.6

Pathological examination of the resected specimen is an essential step in determining node positivity, cancer stage, indication for the use of adjuvant chemotherapy and patient prognosis. The greater the number of nodes exam-ined, the more confidence can be placed in the reported nodal status of the patient.7 The American Joint Commis-sion on Cancer and the College of American Pathologists recommend examination of a minimum of 12 lymph nodes to accurately diagnose stage II disease.8 This has now become a measure of surgical resection adequacy in stage I–III CRC.

Patients presenting with obstructing or perforated can-cers requiring emergent surgery represent a high-risk popu lation with poor outcomes compared to those with nonemergently resected cancers. The cause for decreased survival in this high-risk population has been poorly evalu-ated in the literature.9 It has been suggested that owing to technical difficulty or instability of the patient, inadequate lymph node harvest may occur, resulting in pathologically understaged or indeterminate staging of the patient. Con-sequently these patients may not receive the survival bene-fits of adjuvant chemotherapy, or they may be subjected to unnecessary side effects of chemotherapeutic drugs.10,11

The objective of our study was to compare the adequacy of nodal staging in patients undergoing emergency surgery with those undergoing elective surgery for CRC in a high volume tertiary referral Canadian hospital.

Methods

Database

Patient information was entered prospectively into a data-base from January 2008 to December 2013. Patient infor-

mation, surgical information, neoadjuvant and adjuvant therapy, pathology information, tumour-node-metastasis (TNM) classification and staging were entered manually. Surgical nature (elective v. emergent) was determined from the operative notes and International Classification of Diseases (ICD)-10 codes during individual patient data entry. The indication for emergent surgery was not included in the original data set. Quarterly quality assess-ment data runs and random chart audits were completed to assure accuracy of the data set. We obtained informa-tion on pathologic staging and lymph node count from the synoptic pathology reports.

Exposure and outcomes

The primary exposure was the nature of surgery (emer-gency v. elective surgery). The primary outcome was ade-quacy of lymph node harvest, with 12 or more nodes con-sidered adequate. In addition, we compared the mean number of nodes harvested between groups.

We explored several factors to determine if they modi-fied the effect of nature of surgery on nodal harvest. These included surgeon subspecialty training (colorectal, surgical oncology, general surgery), tumour site (right, transverse, left, rectum, multiple), type of resection (right hemicolectomy, left hemicolectomy, sigmoid resection, segmental resection, abdominoperineal resection (APR), Hartmann, low anterior resection, subtotal colectomy) and pathologic stage. Owing to location and the expected difference in use between elective and emergent surgery, we grouped low anterior resections, APR and Hartmann procedure together for analysis.


We performed all statistical analyses using STATA soft-ware version 12.0 (Statacorp).

The crude association between nature of surgery and adequacy of lymph node harvest was determined using a Pearson χ2 test. The difference in means was calculated using analysis of variance between groups. We completed a Mantel–Haenszel analysis to assess the effect of surgeon training, tumour site, type of resection and pathologic stage on the adequacy of lymph node harvest between groups.

We then performed logistic regression analysis to assess the association between adequacy of lymph node harvest and nature of surgery, adjusting for surgeon training, tumour site, type of surgery and pathologic stage. Signifi-cance testing was completed using the likelihood ratio test.

Results

Of the 1356 patients enrolled in the database, 1279 patients (94%) had complete pathologic information and were


RESEARCH


included in this study. Of these, 12.6% required an emer-gency operation. Patient characteristics can be found in Table 1. Overall, the most common tumour sites were right-sided (29.4%), left-sided or sigmoid (28.9%) or rectal (30.5%). The surgeons’ subspecialties included colorectal training (35.0%), surgical oncology (9.8%) and general surgery (54.9%).

The mean number of nodes harvested and proportion of adequate lymph node sampling can be found in Table 2. The emergency group on average had more lymph nodes sampled than the elective group (mean difference +2.8, 95% confidence interval [CI] 0.6–5.1, p = 0.012). There was no difference in the proportion of adequate harvests between the emergency and elective groups (risk ratio 1.01, 95% CI 0.94–1.09, p = 0.79). Furthermore, no trends

were identified in the inadequate node harvest data set. The proportion of cases with fewer than 5 nodes and 5–9 nodes harvested were comparable in both emergent and elective groups.

We completed stratified analyses to assess the effect of surgeon training, tumour site, type of resection, pathologic stage and age on the association between adequacy of lymph node harvest and surgical nature (Table 3).

The Mantel–Haenszel analysis revealed that the associa-tion between adequacy of lymph node harvest and surgical nature was not influenced by surgical training (test of homogeneity, p = 0.31), tumour site (p = 0.31) type of resection (p = 0.96), pathologic stage (p = 0.45) or age (p = 0.46; Table 4).

A logistic analysis was completed assessing the associa-tion between lymph node adequacy and surgical nature, adjusting for surgeon training, tumour site, type of resec-tion, pathologic stage and age. We found no evidence of an association between surgical nature and lymph node har-vest, after adjusted analysis. The odds ratio of an adequate resection in the emergency group compared with the elec-tive group was 0.77 (95% CI 0.45–1.31, p = 0.35; Table 4).

Discussion

Our results showed that there was no evidence of a differ-ence in the adequacy of lymph node harvest between elec-tive and emergency surgery. This was true, even after adjusting for age, tumour site, type of resection, surgeon training and pathologic stage.

Strengths and limitations

This study used information from a prospectively col-lected database of patients with CRC. We had complete nodal information on more than 90% of patients who were included in the study. The accuracy of the pathology reports have been assured and maintained with routine audits. In addition, we had complete information on age, type of resection, tumour site, full pathologic staging and surgeon training. This allowed us to analyze the in depend-ent effects of the nature of surgery after adjusting for these potential confounders.

Table 1. Characteristics of study participants

Group; no. (%)

Characteristic TotalElective surgery

Emergency surgery

Nature of surgery 1342 (100) 1181 (87.4) 161 (12.6)

Age, yr

< 50 91 (7.1) 75 (6.7) 16 (9.9)

50–59 204 (16.0) 190 (17.0) 14 (8.7)

60–69 343 (26.8) 297 (26.6) 46 (28.6)

70–79 373 (29.2) 334 (29.9) 39 (24.2)

≥ 80 268 (21.0) 222 (19.9) 46 (28.6)

Tumour site

Right colon 376 (29.3) 325 (29.1) 51 (31.7)

Transverse colon 123 (9.6) 95 (8.5) 29 (17.4)

Left or sigmoid colon 370 (28.9) 307 (27.5) 63 (39.1)

Rectum 390 (30.5) 378 (33.8) 12 (7.5)

Multiple 10 (0.8) 6 (0.5) 4 (2.5)

Other 10 (0.8) 7 (0.6) 3 (1.9)

Surgery type

Right colectomy 433 (33.9) 367 (32.8) 66 (41.0)

Left colectomy 138 (10.8) 124 (11.1) 14 (8.7)

LAR 406 (31.7) 384 (34.4) 22 (13.7)

APR 129 (10.1) 128 (11.5) 1 (0.6)

Hartmann 31 (2.4) 14 (1.3) 17 (10.6)

Subtotal colectomy 76 (5.9) 45 (4.0) 31 (19.3)

Segmental colectomy 40 (3.1) 30 (2.7) 10 (6.2)

Other 13 (1.0) 13 (1.2) 0 (0)

Surgeon training

Colorectal 448 (35.0) 417 (37.3) 31 (19.3)

Surgical oncology 125 (9.8) 109 (9.8) 16 (9.9)

General surgery 702 (54.9) 589 (52.7) 113 (70.2)

Other 4 (0.3) 3 (0.3) 1 (0.6)

Pathologic stage

Stage 0 50 (3.9) 50 (4.5) 0 (0)

Stage I 226 (17.7) 224 (20.0) 2 (1.2)

Stage II 402 (31.4) 354 (31.7) 48 (29.8)

Stage III 465 (36.4) 404 (36.1) 61 (37.9)

Stage IV 135 (10.6) 85 (7.6) 50 (31.1)

Unknown 1 (0.1) 1 (0.1) 0 (0)

APR = abdominoperineal resection; LAR = low anterior resection.

Table 2. Mean number of lymph nodes removed and proportion of adequate lymph node harvest, by surgical nature

Group; mean (SD) or no. [%]

FactorElective surgery

Emergency surgery p value

No. of nodes 19.1 (13.3) 22.0 (13.8) 0.012

Adequacy of lymph node harvest 0.79

Adequate, ≥ 12 nodes 928 [83.0] 135 [83.9]

Inadequate, < 12 nodes 190 [17.0] 26 [16.1]

SD = standard deviation.


RECHERCHE


Limitations of the study may include misclassification of the nature of surgery. We extracted the nature of surgery from operative notes. We were unable to further validate

the nature of surgery. In addition, the database did not capture the indication for surgery in the emergency group. It is possible that operating for bleeding, obstruction or perforation could affect the adequacy of the lymph node harvest differently. The database included patients who were treated at an academic institution by surgeons with varying levels of training. The results of this study may not translate to the community hospital experience, where training may be similar but volumes and case complexity may be variable. An additional limitation is that adequacy of lymph node harvest can be affected by the reporting pathologist.12 Our database did not distinguish among reporting pathologists, and adequacy of nodal harvest by pathologist was not available.

Strengths and limitations in comparison to previous publications

A previous study by Lewis and colleagues13 examined 296 patients operated for colon cancer, 15% of whom had an emergency operation. Comparing the results from our study and theirs, we found a similar proportion of patients requiring emergency surgery (15% v. 12.6%). The study by Lewis and colleagues did not include patients with rec-tal cancers. In addition, there was a smaller proportion of inadequate harvest in the elective group in their study compared with ours (11.9% v. 17.0%), but there was no difference in the proportion of inadequate harvest in the emergency group (14.0% v. 16.1%). Univariate analysis in the study by Lewis and colleagues found no association between nature of surgery and adequacy of lymph node harvest (p = 0.70). They did not attempt to adjust for the effects of surgeon training, tumour site, resection type or pathologic stage.

Previous studies have found that specialty training may result in differences in adequacy of node harvest.14,15 In addi-tion, tumour site has previously been found to affect adequacy of nodal harvest.16,17 Our study stratified and then adjusted for these 2 factors as well as resection type and pathologic stage. Even after adjusting for these important factors, we found no difference in the adequacy of nodal harvest.

Table 3. Stratified analysis of adequacy of lymph node harvest, by surgical nature

Group; no. (% inadequate)

FactorElective surgery

Emergency surgery p value

Surgeon training

Colorectal 417 (17.3) 31 (9.7) 0.28

Surgical oncology 109 (18.4) 16 (6.3) 0.23

General surgery 589 (16.5) 113 (19.5) 0.44

Other 3 (33.3) 1 (0.0) 0.51

Tumour site

Right colon 325 (7.4) 51 (9.8) 0.55

Transverse colon 95 (9.5) 28 (3.6) 0.32

Left or sigmoid colon 307 (20.5) 63 (22.2) 0.76

Rectum 378 (24.3) 12 (25.0) 0.96

Multiple 6 (0.0) 4 (0.0) N/A

Other 7 (28.6) 3 (100.0) 0.038

Surgery type

Right colectomy 367 (7.4) 66 (9.1) 0.63

Left colectomy 124 (18.6) 14 (14.3) 0.70

LAR/APR/Hartmann 539 (20.8) 40 (27.5) 0.32

Subtotal colectomy 45 (8.9) 31 (9.7) 0.91

Segmental colectomy* 30 (36.7) 10 (40.0) 0.85

Other 13 (100.0) 0 (0.0) N/A

Pathalogic stage

Stage 0 50 (36.0) 0 N/A

Stage I 224 (23.6) 2 (50.0) 0.39

Stage II 354 (15.0) 48 (16.7) 0.76

Stage III 404 (11.6) 61 (6.6) 0.24

Stage IV 85 (21.2) 50 (26.0) 0.52

Unknown 1 (100.0) 0 N/A

Age, yr

< 50 75 (12.0) 16 (12.5) 0.96

50–59 190 (16.8) 14 (28.6) 0.27

60–69 297 (17.2) 46 (8.7) 0.15

70–79 334 (20.4) 39 (23.1) 0.69

≥ 80 222 (13.5) 46 (15.2) 0.76

APR = abdominoperineal resection; LAR = low anterior resection; N/A = not applicable. *Nonformal resection (e.g., cecectomy, segment of sigmoid).

Table 4. Mantel–Haenszel and logistic regression analysis

Type of analysis OR (95% CI)Significance

testingTest of

homogeneity

Mantel–Haenszel odds

Adjusted for training 1.06 (0.68–1.68) p = 0.77 p = 0.31

Adjusted for site 0.87 (0.54–1.41) p = 0.57 p = 0.31

Adjusted for type of resection 0.82 (0.50–1.31) p = 0.40 p = 0.96

Adjusted for pathologic stage 0.99 (0.61–1.63) p = 0.99 p = 0.45

Adjusted for age group 1.01 (0.64–1.58) p = 0.97 p = 0.46

Logistic regression

Adjusted for training, site, type of resection, stage and age group

0.77 (0.45–1.31) p = 0.35 N/A

CI = confidence interval; N/A = not applicable; OR = odds ratio.


RESEARCH


Population-based studies have identified age as a statis-tically significant variable affecting adequacy of lymph node resection.18,19 Baxter and colleagues18 studied more than 100 000 patients with invasive colon and rectal cancer. Our results show a similar trend with decreasing rates of adequate lymph node resection with increasing age. The rates of ade-quate resection are improved compared with these previous findings of Baxter and colleagues in patients younger than 50 (12% v. 45%) and older than 71 years of age (16.9% v. 65%).18 Our stratified analysis assessing the effect of age on adequacy of lymph node resection was not significant when comparing the emergent and elective groups.

ConClusion

Patients undergoing emergency surgery had no difference in the adequacy of nodal staging compared with their elective counterparts. The commonly held belief that inadequate staging occurs more frequently in the emer-gency group was not supported by our patient population and analysis.Competing interests: None declared.

Contributors: All authors designed the study. M. Brackstone acquired the data, which S. Patel and S. Patel analyzed. S. Patel and S. Patel wrote the article, which all authors reviewed and approved for publication.

References

1. Canadian Cancer Society, Steering Committee on Cancer Statis-tics. Canadian Cancer Statistics 2012. Toronto (ON): Canadian Cancer Society; 2012.

2. NIH consensus conference. Adjuvant therapy for patients with colon and rectal cancer. JAMA 1990;264:1444-50.

3. Macdonald JS. Adjuvant therapy of colon cancer. CA Cancer J Clin 1999;49:202-19.

4. Twelves C, Wong A, Nowacki MP, et al. Capecitabine as adjunvant treatment for stage II colon cancer. N Engl J Med 2005;352: 2696-704.

5. André T, Boni C, Navarro M, et al. Improved overall survival with oxaliplatin, flurouracil, and leucovorin as adjuvant treatment in stage II or III colon cancer in the MOSAIC trial. J Clin Oncol 2009;27:3109-16.

6. Benson AB III, Schrag D, Somerfield MR, et al. American Society of Clinical Oncology recommendations on adjuvant chemotherapy for stage II colon cancer. J Clin Oncol 2004;22:3408-19.

7. Swanson RS, Compton CC, Stewart AK, et al. The prognosis of T3N0 colon cancer is dependent on the number of lymph nodes examined. Ann Surg Oncol 2003;10:65-71.

8. NCCN Clinical practice guidelines in Oncology: Colon Cancer. Available: www.nccn.org (accessed 2013 March 10).

9. Carraro PG, Segala M, Cesana BM, et al. Obstruction colonic can-cer: failure and survival patterns over a ten-year follow-up after one-stage curative surgery. Dis Colon Rectum 2001;44:243-50.

10. Gill S, Loprinzi CL, Sargent DJ, et al. Pooled analysis of flurouracil-based adjuvant therapy for stage II and III colon cancer: Who bene-fits and by how much? J Clin Oncol 2004;22:1797-806.

11. Serpell JW, McDermott FT, Katrivessis H, et al. Obstructing car-cinomas of the colon. Br J Surg 1989;76:965-9.

12. Evans MD, Barton K, Rees A, et al. The impact of surgeon and pathologist on lymph node retrieval in colorectal cancer and its impact on survival for patients with Dukes’ stage B disease. Colorectal Dis 2008;10:157-64.

13. Lewis A, Akopian G, Carillo S, et al. Lymph node harvest in emer-gent versus elective colon resections. Am Surg 2012;78:1049-53.

14. Barbas A, Turley R, Mantyh C, et al. Advanced fellowship training is associated with improved lymph node retrieval in colon cancer resection. J Surg Res 2011;170:e41-6.

15. Nicholl MB, Wright BE, Conway WC, et al. Does specialized sur-gical training increase lymph node yield in colon cancer? Am Surg 2009;75:887-91.

16. Bilimoria KY, Palis B, Stewart AK, et al. Impact of tumor location on nodal evaluation for colon cancer. Dis Colon Rectum 2008; 51:154-61.

17. Bernhoff R, Holm T, Sjovall A, et al. Increased lymph node harvest in patients operated on for right-sided colon cancer: a population-based study. Colorectal Dis 2012;14:691-6.

18. Baxter NN, Virnig DJ, Rothenberger DA, et al. Lymph node evalu-ation in colon cancer patients: a population-based study. J Natl Cancer Inst 2005;97:219-25.

19. Bilimoria KY, Stewart AK, Palis BE, et al. Adequacy and impor-tance of lymph node evaluation for colon cancer in the elderly. J Am Coll Surg 2008;206:247-54.




Trauma Non-Technical Training (TNT-2): the development, piloting and multilevel assessment of a simulation-based, interprofessional curriculum for team-based trauma resuscitation

E ffective trauma resuscitation requires the coordinated effort of an inter-disciplinary team. Medical error is common during trauma resuscita-tions, occurring even in well-resourced settings with experienced prac-

titioners. The majority of errors are nontechnical in nature, stemming from ineffective team leadership, nonstandardized communication among team members, lack of global situational awareness, poor use of resources and inappropriate triage and prioritization. Lessons from high-hazard, high- reliability industries have therefore informed the development of medical and surgical crisis resource management (CRM) principles and team training applications to address local and domain-specific needs. There is currently no formally derived or systematically evaluated nontechnical skills curriculum for Canadian surgical trainees. Simulation-based CRM training provides an opportunity for focused instruction, deliberate practice, feedback and assess-ment on the communicator, collaborator and manager roles espoused by the CanMEDS framework in a manner that is consistent and reproducible and poses no threat to patients. We describe the development, piloting and multi level evaluation of a novel, interprofessional, simulation-based trauma team training curriculum for Canadian surgical trainees: Trauma Non- Technical Training (TNT-2).

The TNT-2 currirulum was piloted as a prospective, 2-phase, single blinded education study and was informed by a Best Evidence Medical Edu-cation systematic review1 and a focused literature review by the authors.2 The strength of the TNT-2 study stems from the multilevel curriculum assessment, with objective assessment of team performance as the primary study outcome.

The course was held at the Allen Waters Family Simulation Centre at St. Michael’s Hospital in Toronto, Ont., and used SimMan (Laerdal), an operator- controlled, full-sized human patient simulator. The “health” of Sim-Man can be interactively manipulated on the basis of management decisions. The simulation theatre was set up to resemble a trauma room, and teams had access to equipment and diagnostic test results in real time. Two confederates were trained to respond in a standardized fashion according to scenario scripts. A single experienced operator controlled all scenarios, and teams were video-recorded for subsequent blinded evaluation.

Aristithes G. Doumouras, MD, BHSc* Itay Keshet, MBBS* Avery B. Nathens, MD, PhD†‡ Najma Ahmed, MD, PhD*‡ Christopher M. Hicks, MD, MEd*§

From the *Department of Surgery, Keenan Research Center of the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ont., †Department of Surgery, Sunnybrook Health Sciences Centre, Toronto, Ont., ‡Division of Gen-eral Surgery, Department of Surgery, University of Toronto, Toronto, Ont., §Department of Emergency Medicine, St. Michael’s Hospital, Division of Emer-gency Medicine, Department of Medicine, University of Toronto, Toronto, Ont.

This work was presented at the 2013 Canadian Association of Emergency Phys icians Annual Conference, Vancouver BC, June 5, 2013.

Accepted for publication Jan. 27, 2014

Correspondence to: C. Hicks 30 Bond St., 1-008c Shuter Wing Toronto ON M5B 1W8 [email protected]

DOI: 10.1503/cjs.000814

Medical error is common during trauma resuscitations. Most errors are non-technical, stemming from ineffective team leadership, nonstandardized com-munication among team members, lack of global situational awareness, poor use of resources and inappropriate triage and prioritization. We developed an interprofessional, simulation-based trauma team training curriculum for Can-ad ian surgical trainees. Here we discuss its piloting and evaluation.

Summary

trauma-doum.indd 354 14-09-16 10:54 AM

DISCUSSIONS IN SURGERY


All second-year trainees from the General Surgery pro-gram at the University of Toronto were invited to partici-pate. In addition, 4 experienced trauma nurses were recruited to participate. Nineteen individuals participated in the first phase, and 9 (6 trainees and 3 nurses) elected to participate in the follow-up phase.

On the training day, participants were randomly divided into teams comprising 3 trainees, 2 nurses and a facilitator with extensive trauma and education experience. Teams received a standard orientation to the simulator environ-ment, followed by a 20-minute prebriefing course, which included a question and answer period with the facilitator and a viewing of a segment of the film The Deadliest Plane Crash about the Tenerife aviation catastrophe.

Teams participated in 3 peer-reviewed standardized trauma resuscitation scenarios lasting 15 minutes each that were designed to highlight 1 or 2 nontechnical, team-based challenges known to encumber effective trauma team performance. The manner in which participants responded to and negotiated these nontechnical challenges then formed the basis for subsequent debriefings. Debrief-ings consisted of 30 minutes of feedback by the facilitators and focused on scenario-specific learning objectives, such as managing authority gradients, recognizing and avoiding fixation errors, resource utilization, problem solving and team communication skills.

Six months after their initial training, participants volun-tarily returned to the simulation centre to participate in the second phase using new scenarios with similar training goals, objectives and levels of difficulty. Participants were rerandomized into teams and facilitated through 3 scenario–debriefing couplets in a manner similar to the first phase.

The impact of TNT-2 was evaluated on multiple levels. Our primary outcome, team performance, was assessed using the Mayo High Performance Team Scale (MHPTS), which rates team performance based on the consistency of 16 different criteria and is designed to evaluate global team performance.3 We used the Ottawa Global Rating Scale (OGRS) to evaluate the performance of the team leader; the scale consists of 5 nontechnical criteria and a global assessment score.4 The OGRS and MHPTS were com-pleted by the team facilitator immediately after each scen-ario and before the debriefing. Two trained blinded reviewers subsequently analyzed recorded data and rated performance on the MHPTS and OGRS scales.

To measure attitudinal shifts occurring as a result of training, participants completed the Human Factors Atti-tudes Survey (HFAS) before and after each scenario on each training day. Positive changes in HFAS scores reflect improved attitudes toward team-based behav-iours.5 We quantified participants’ perceptions of training using the Participant Evaluation of Training Quality (PETQ) tool. The PETQ questionnaire measures the face validity of the simulation environment, the percep-tions on the usefulness of the intervention and perceived

personal benefit. The HFAS and PETQ scores were sec-ondary study outcomes.

From our preliminary analysis, the TNT-2 curriculum was feasible and well received, and it provided a strategy for teaching and evaluating key nontechnical behaviours pertinent to team-based trauma resuscitation. The MHPTS and OGRS scores improved but did not reach statistical significance. Considering the small number of participants, this result was not surprising. Decay in CRM skills by trainees did not occur, and the 6-month interval between phases 1 and 2 is the longest reported to date for this type of training, suggesting that biannual instruction may be sufficient for nontechnical skill maintenance. Moreover, to our knowledge, TNT-2 is the first resident study to use team performance, as evaluated by a validated behavioural rating scale, as the primary outcome.

Significant, positive changes in HFAS scores suggest that an important attitudinal shift regarding team-based behaviours occurred as a result of TNT-2 training. Several observations on the PETQ, including scenario realism and satisfaction with high-fidelity simulation training, averaged greater than 5 on a 6-point Likert scale. In addition, there was no change in PETQ scores across all scenarios in both phases, which suggests that standardized, realistic trauma team training can be created and maintained even after in itial training and exposure.

Finally, there was excellent agreement between the 2 blinded reviewers and between blinded assessment and unblinded, real-time raters (facilitators) using the MHPTS and the OGRS. This result informs the argument that behavioural rating scales may be reliable for real-time assessment and feedback.Competing interests: This work was supported in part by funds from a University of Toronto Education Development Fund grant (N. Ahmed and C.M. Hicks.), a St. Michael’s Hospital Keenan Research Centre Scholarship and a Queen’s University Research Studentship (A.G. Doumouras).

Contributors: All authors contributed substantially to writing and revising and to the conception and design of the manuscript and approved the final version submitted for publication.

References

1. Issenberg SB, McGaghie WC, Petrusa ER, et al. Features and uses of high-fidelity medical simulations that lead to effective learning: a BEME systematic review. Med Teach 2005;27:10-28.

2. Doumouras AG, Keshet I, Nathens AB, et al. A crisis of faith? A review of simulation in teaching team-based, crisis management skills to surgical trainees. J Surg Educ 2012;69:274-81.

3. Malec JF, Torsher LC, Dunn WF, et al. The Mayo High Perform-ance Teamwork Scale: reliability and validity for evaluating key crew resource management skills. Simul Healthc 2007;2:4-10.

4. Kim J, Neilipovitz D, Cardinal P, et al. A pilot study using high-fidelity simulation to formally evaluate performance in the resusci-tation of critically ill patients: the University of Ottawa critical care medicine, high-fidelity simulation, and crisis resource management I study. Crit Care Med 2006;34:2167-74.

5. Grogan EL, Styles R, France D, et al. The impact of aviation-based teamwork training on the attitudes of health care professionals. J Am Coll Surg 2004;199:843-8.

trauma-doum.indd 355 14-09-16 10:54 AM



Percutaneous drainage of Morel-Lavallée lesions when the diagnosis is delayed

M orel-Lavallée lesions are a closed internal degloving that occurs most commonly over the greater trochanter region, but can also occur in other regions, such as the knee.1 The injury is typically

caused by a vertical shearing force over soft tissue that abruptly separates skin and subcutaneous tissue from the underlying fascia, thus creating a dead space that becomes filled with hematoma and necrotic fat.1 The condition generally takes several days to develop, and delayed diagnosis has been reported to occur in one-third of cases or more.1 The condition is typically treated with open débridement of the degloved areas and complete removal of hematoma and necrotic tissue.2,3 However, the vertical blood vessel branches from the underlying muscle and deep fascia have been separated from the degloved skin by the injury, and open débridement may jeopardize the subdermal arterial plexus, the only remaining blood supply to the skin in the area of the lesion.

We performed percutaneous drainage to treat 3 men and 5 women with a delayed diagnosis of Morel-Lavallée lesions and found the procedure to be effective; it was associated with minimal morbidity as well as preservation of the remaining blood supply to the skin. The mean age of our 8 patients was 41.9 years, and the mean time from injury to diagnosis was 11.9 (range 8–17) days. The criteria for diagnosis were a local fluctuant area with skin mobility and systemic symptoms, such as fever and hyperleukocytosis (Fig. 1A), and imaging evidence on ultrasound (Fig. 1B) or computed tomography scan. All patients were treated within 1 day after diagnosis.

Ultrasonography was performed to detect the location and area of the lesion and to determine the location of the operative incisions. Several 2-cm incisions were made and suction tips inserted through the incisions into the lesion (Fig. 1C). Suction was then applied to remove hemorrhagic fluid and necrotic and liquefied tissue. In some patients, necrotic fascia were scraped out through the incision using a plastic brush. A planer tool used in arthroscopy was also used and effectively removed necrotic adipose tissue. After fluid and necrotic tissue were removed, extensive irrigation was performed. Finally, abdominal double-lumen catheters were placed subcutaneously, and continuous suction was applied (Fig. 1D).

We administered cefuroxime intravenously each day until bacterial culture results were available. If the catheters became obstructed, another operation was performed for percutaneous drainage, débridement and catheter replacement. When the drainage was under 30 mL for a 24-hour period, all catheters were removed, the incisions were sutured, and elastic bandages were used to apply

Biao Zhong, MD Chi Zhang, MD Cong-feng Luo, MD

From the Orthopaedic Department, 6th People’s Hospital affiliated to Shanghai Jiaotong University, Shanghai, China


Correspondence to: C. Zhang Orthopaedic Department 6th People’s Hospital affiliated to Shanghai Jiaotong University 600 Yishan Rd. Shanghai, China, 200233 [email protected]

DOI: 10.1503/cjs.034413

Morel-Lavallée lesions are a closed internal degloving, and open débride-ment can damage the only remaining blood supply to the skin. We per-formed percutaneous draining and débridement to treat 8 patients in whom the diagnosis of Morel-Lavallée lesions was delayed more than 1 week. Here we discuss our treatment procedures and the outcomes in these 8 patients. We consider percutaneous drainage to be an effective treatment for patients with delayed diagnosis of Morel-Lavallée lesions.

Summary

perc-zhang.indd 356 14-09-16 10:55 AM



pressure to the degloved skin. Healing of the lesion was defined as disappearance of the fluctuant lesion and loss of excessive skin mobility upon manual examination (Fig. 1E).

Percutaneous drainage was performed successfully without complications in all patients, and systemic inflammatory response syndrome scores all decreased to 0 by the third postoperative day. Because of catheter obstruction, 6 patients received a second débridement, and 2 received a third proced ure. Complete healing of the soft tissue and skin occurred in 6 patients. Skin necrosis occurred in 2 patients and was treated by skin grafting. The mean soft tissue healing time was 3.25 weeks. There were no reoccurrences of the lesions and no deep infections or other complications during the 1year followup period.

While Harma and colleagues4 advocated that MorelLavallée lesions in the pelvic and gluteal regions can be managed conservatively when the overlying skin is intact and the fluid accumulation is not excessive, open débridement is generally recommended to evacuate any hematoma and remove necrotic tissue once an injury is identified because neglected lesions can become infected.2,3 Nonetheless, open débridement may violate the blood supply of the injured skin and introduces a risk of infection.

Percutaneous management of MorelLavallée lesions was introduced by Tseng and Tornetta5 in order to preserve the subdermal arterial plexus. In their series of 19 patients, percutaneous drainage with débridement, irrigation and suction drainage was performed through 2 small incisions in the skin, and all patients achieved soft tissue healing without recur

rence or infection. There are some differences between our method and theirs. First, we made more incisions for complete débridement and to enable insertion of doublelumen catheters to provide circulation for postoperative drainage. Second, we used continuous suction.

Percutaneous drainage is an effective treatment for patients with a delayed diagnosis of MorelLavallée lesions. The procedure is associated with minimal morbidity and preserves the remaining blood supply to the skin. Percutaneous treatment may be more complex and last longer than open surgery, but the benefits outweigh these factors.Competing interests: None declared.

Contributors: All authors contributed substantially to writing and revising and to the conception and design of the manuscript and approved the final version submitted for publication.

References

1. Powers ML, Halem SF, Sundaram M. Diagnosis: MorelLavalee lesion. Orthopedics 2007;30:3223.

2. Hak DJ, Olson SA, Matta JM. Diagnosis and management of closed internal degloving injuries associated with pelvic and acetabular fractures: the MorelLavallee lesion. J Trauma 1997;42:104651.

3. Carlson DA, Smmons J, Sando W, et al. MorelLavalee lesions treated with debridement and meticulous dead space closure: surgical technique. J Orthop Trauma 2007;21:1404.

4. Harma A, Inan M, Ertem K. The MorelLavallée lesion: a conservative approach to closed degloving injuries. Acta Orthop Traumatol Turc 2004;38:2703.

5. Tseng S, Tornetta P III. Percutaneous management of Morel Lavallee lesions. J Bone Joint Surg Am 2006;88:926.

Fig. 1: (A) A 53-year-old man with a femoral shaft fracture treated with closed intramedullary nailing. Local swelling appeared with gradual development of fluctuance and skin hypermobility. (B) Ultrasound showing a fluid collection in the subcutaneous tissue adjacent to the fascia lata, confirming a Morel-Lavallée lesion. (C) Percutaneous drainage was performed through a 2-cm incision with suction tips. (D) Several incisions were made for débridement, and double-lumen catheters were placed for suction drainage. (E) Three months postoperatively the soft tissue had healed without complications.

perc-zhang.indd 357 14-09-16 10:55 AM



CAGS AND ACS EVIDENCE BASED REVIEWS IN SURGERY. 50

Is early transfusion of plasma and platelets in higher ratios associated with decreased in-hospital mortality in bleeding patients?

The term “evidence-based medicine” was first coined by Sackett and colleagues as “the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients.”1 The key to practising evidence-based medicine is applying the best current knowledge to decisions in individual patients. Medical knowledge is continually and rapidly expanding. For clinicians to practise evidence-based medicine, they must have the skills to read and interpret the medical literature so that they can determine the validity, reliability, credibility and utility of individual articles. These skills are known as critical appraisal skills, and they require some knowledge of biostatistics, clinical epidemiology, decision analysis and economics, and clinical knowledge.

Evidence Based Reviews in Surgery (EBRS) is a program jointly sponsored by the Canadian Association of General Surgeons (CAGS) and the American College of Sur-geons (ACS). The primary objective of EBRS is to help practising surgeons improve their critical appraisal skills. During the academic year, 8 clinical articles are chosen for review and discussion. They are selected for their clinical relevance to general sur-geons and because they cover a spectrum of issues im port ant to surgeons, including causation or risk factors for disease, natural history or prognosis of disease, how to quantify disease, diagnostic tests, early diagnosis and the effectiveness of treatment. A methodological article guides the reader in critical appraisal of the clinical article. Methodological and clinical reviews of the article are performed by experts in the rele-vant areas and posted on the EBRS website, where they are archived indefinitely. In addition, a listserv allows participants to discuss the monthly article. Surgeons who participate in the monthly packages can obtain Royal College of Physicians and Sur-geons of Canada Maintenance of Certification credits and/or continuing medical edu-cation credits for the current article only by reading the monthly articles, participating in the listserv discussion, reading the methodological and clinical reviews and com-pleting the monthly online evaluation and multiple choice questions.

We hope readers will find EBRS useful in improving their critical appraisal skills and in keeping abreast of new developments in general surgery. Four reviews are pub-lished in condensed versions in the Canadian Journal of Surgery and 4 are published in the Journal of the American College of Surgeons. For further information about EBRS, please refer to the CAGS or ACS websites. Questions and comments can be directed to the program administrator, Marg McKenzie, at [email protected].

Reference

1. Evidence-Based Medicine Working Group. Evidence-based medicine. JAMA 1992;268:2420-5.

Selected article

Holcomb JB, del Junco DJ, Fox EE, et al.; the PROMMTT Study Group. The Prospective, Observational Multicentre Major Trauma Transfusion (PROMMTT) Study. Arch Surg 2012 15:1-10.

Andrew W. Kirkpatrick, MD Chad G. Ball, MD Juan Duchesne, MD Katerina Pavenski, MD for the Members of the Evidence Based Reviews in Surgery Group

*The CAGS/ACS Evidence Based Reviews in Surgery Group comprises N.N. Baxter, K.J. Brasel, C.J. Brown, P.K. Chaudhury, C.M. Divino, E. Dixon, G.W.N. Fitzgerald, S.M. Hameed, H.J. Henteleff, T.G. Hughes, L.S. Kao, A.W. Kirkpatrick, S. Latosinsky, T.M. Mastracci, R.S. McLeod, A.M. Morris, T.M. Pawlik, L.K. Temple and M.E. McKenzie.

Correspondence to: M. McKenzie Administrative Coordinator, EBRS Mount Sinai Hospital, L3-010 60 Murray St., PO Box 23 Toronto ON M5T 3L9 fax 416 586-5932 [email protected]

DOI: 10.1503/cjs.010314

casgebrs-kirk.indd 358 14-09-16 11:03 AM



Key points about the article

Question: Is early transfusion of plasma:red blood cell (RBC) and platelet:RBC in higher ratios associated with decreased in-hospital mortality in bleeding patients? Design: Prospective cohort study. Setting: Ten level 1 U.S. trauma centres. Patients: Adult trauma patients sur-viving for 30 minutes after admission who received a transfusion of at least 1 unit of RBCs within 6 hours of admission and at least 3 total units of RBCs, plasma or platelets within 24 hours. Main outcome: In-hospital mortality. Results: Of a total of 34 632 patients, 905 (2.6%) met the inclusion criteria. Plasma:RBC and platelet:RBC ratios were not constant during the first 24 hours (both p < 0.001). In a multivariable time- dependent Cox model, increased plasma:RBC ratios (adjusted hazard ratio [HR] 0.31, 95% confidence interval [CI] 0.16–0.58) and platelet:RBC ratios (adjusted HR 0.55, 95% CI 0.31–0.98) were independently associated with decreased 6-hour mortality when hemorrhagic death predominated. In the first 6 hours, patients with ratios less than 1:2 were 3 to 4 times more likely to die than patients with ratios of 1:1 or higher. After 24 hours, plasma and platelet ratios were not associated with mortality. Conclusion: Higher plasma:RBC and platelet:RBC ratios early in resuscitation were associated with decreased mor-tality in patients who received transfusions of at least 3 units of blood products during the first 24 hours after admission. Further assessment with a randomized con-trolled trial is required.

commentary

The term damage control resuscitation (DCR) describes a therapeutic approach to critically injured patients with ongoing hemorrhage.1 It involves simultaneous therapies to arrest persistent bleeding (prehospital, surgical and/or percutaneous techniques) and resuscitate with a more rapid, balanced and aggressive transfusion of blood com-ponents that theoretically approximate whole blood (plasma, platelets, RBCs). In an ideal setting, DCR approaches at least a 1:2 ratio of plasma:RBC and often a 1:1:1 ratio of plasma:platelet:RBC.2 This technique also possesses the added benefit of minimizing crystalloid administration and, therefore, seems to reduce coagu-lopathy, acidosis, hypothermia, endothelial permeability and the total time to definitive closure of the patient’s abdominal wall.

The classical approach to massive hemorrhage man-agement promulgated by older guidelines consisted of providing blood components as per laboratory-based triggers; for example, plasma transfusion was indicated to keep an international normalized ratio higher than 1.5 in a bleeding patient. In 2007, however, a report by Borgman and colleagues3 challenged this approach by

proposing early transfusion at higher plasma:RBC ratios. This retrospective work was supported by biologic plaus-ibility and basic clinical science revealing that coagulo-pathy develops early in about 25% of injured patients and is associated with worse clinical outcomes. This approach seemed to be associated with remarkable clinical out-comes. Thus, the approach was quickly popularized and many more observational studies followed, many of which were criticized for poor methodological quality and survival bias.

The PROMMTT study,4 therefore, constituted an important multicentre effort to address these questions in the most rigorous fashion short of a large multicentre ran-domized controlled trial. Many if not most of the previous studies were threatened by either survival bias (patients living long enough to receive the treatment appear to do better than those who die too early to receive it) or the competing mortality bias (causes of death other than hem-orrhage begin to dominate trauma patient hospital course after the first 24 hours). However, the PROMMTT study carefully recorded the blood-component ratios at various times through the critical phases of care. Research assis-tants were available at all hours to screen and enroll patients and record the exact times of fluid infusion and blood-component transfusion as well as patient outcomes during direct observation. Direct bedside observation began at trauma team activation and continued until active resuscitation ended (defined as the time the centre trans-fusion protocol was discontinued, death occurred, or 2 hours elapsed since the last blood product transfusion, whichever came first). The study is unique in collecting these critical data with great precision. The investigators also avoided using the traditional definition of massive transfusion to determine eligibility, and the statistical ana-lytic approaches attempted to minimize the effect of sur-vival bias.

There were 34 362 trauma admissions in the 10 cen-tres over an average of 58 weeks. Data collection was in itiated for 12 560 (36.6%) patients, and of these 1245 (3.6%) met all PROMMTT study eligibility criteria. A total of 905 (2.6%) adult trauma patients who survived at least 30 minutes after admission and received at least 1 unit of RBCs within 6 hours of admission and at least 3 units of RBCs within 24 hours at 10 U.S. level 1 trauma centres were enrolled in the study. A distinct attribute of the study was the fact that the authors included patients who experienced major trauma rather than only those who were massively bleeding. In contrast, previous studies have included patients who required at least 10 units of RBCs in 24 hours.

Using a time-dependent model, researchers assessed the association of increased plasma and platelet ratios on in-hospital mortality. Within the first 6 hours, patients with ratios of less than 1:2 were found to be 3 to 4 times more likely to die than patients with ratios of 1:1. During the


DISCUSSIONS EN CHIRURGIE


first 6 hours, the majority of deaths were attributed to hemorrhage. No association between plasma:RBC or platelet:RBC ratios and mortality was observed after 24 hours of admission, when the majority of deaths were attributed to nonhemorrhagic causes.

The results of the PROMMTT study support the beliefs that in-hospital mortality remains high (21%) in patients who require any RBC transfusions within the first 6 hours, that earlier and higher ratios of plasma and platelets are associated with lower mortality within 6–24 hours after arrival and that this benefit is not observed among survivors beyond 24 hours. Because of its detailed, time-based analysis, the PROMMTT study provides the strongest evidence to date to support this treatment regimen. Despite the limitations, the study showed an apparent survival benefit with close resuscita-tion ratios of plasma:RBC and platelet:RBC in patients with severe hemorrhage. It is important to recognize some limitations of this prospective study. First, the vast majority of trauma patients had blunt trauma and not penetrating trauma. Second, only 35% had the abdom-inal cavity as a source of hemorrhage, with only 24% of the study group undergoing damage control surgery, whereas 26% had compressible limb injuries. Third, the mean quantity of RBC transfusion in the cohort analyzed was greater than 3 units over 24 hours, but it was evident that most of the patients analyzed did not receive more than 10 units of RBCs over 24 hours nor in the first 6 hours. In other words, how sick were these patients? Fourth, patients who died within the first 30 minutes were excluded from the analysis owing to predefined exclusion criteria. This last one raised the concern of survivor bias. Did this group receive any RBCs or plasma? If so, why were they excluded? Finally, no data on coagulation parameters, hemoglobin or platelet counts during resuscitation were provided. Therefore, it is not clear whether the strategy was effective in address-ing hemostatic derangements. No information was pro-vided on the use of tranexamic acid, an antifibrinolytic agent, which has been shown to decrease mortality in trauma patients by a recent randomized controlled trial (CRASH-2 investigators).5 The rate of transfusion-related complications (e.g., volume overload, acute lung injury) were not reported. These complications tend to occur later in the resuscitation (> 6 h later) and may sig-nificantly contribute to patient morbidity and mortality. It would have been interesting to see how many of the surviving patients who received 1:1 resuscitation experi-enced such complications and to learn more about these patients. The potential benefit and safety of the high ratio approach may differ among populations. For exam-

ple, previous studies have shown that women, patients with blunt (v. penetrating) injuries and those with trau-matic brain injuries benefited less from high plasma:RBC ratio transfusion.6–8

While the PROMMTT study adds further evidence to support transfusions with higher plasma:RBC transfu-sions, further studies are needed, especially regarding how to efficiently identify the patients who will benefit from early administration of the therapy. Future studies looking at the infusion rate of each component on mor-tality will also help clarify this question further. Clin-icians cannot be confident, however, that by administer-ing enhanced ratios of plasma and platelets that they will influence the mortality of their seriously injured patients, and a randomized controlled trial is still urgently required. The Pragmatic, Randomized, Optimal Platelet and Plasma Ratios (PROPPR) is a Phase III trial designed to evaluate the difference in 24-hour and 30-day mortal-ity among patients predicted to receive massive transfu-sion (defined as receiving 10 or more units of RBCs within the first 24 h) has been completed, and the results are imminently expected; they may greatly advance this critical area of practice.Competing interests: None declared.

References

1. Stone HH, Strom PR, Mullins RJ. Management of the major coagu-lopathy with onset during laparotomy. Ann Surg 1983;197:532-5.

2. Holcomb JB, Wade CE, Michalek JE, et al. Increased plasma and platelet to red blood cell ratios improves outcome in 466 massively transfused civilian trauma patients. Ann Surg 2008;248:447-58.

3. Borgman MA, Spinella PC, Perkins JG, et al. The ratio of blood products transfused affects mortality in patients receiving massive transfusions at a combat support hospital. J Trauma 2007;63:805-13.

4. Holcomb JB, del Junco DJ, Fox EE, et al.; PROMMTT Study Group. The prospective, observational, multicenter, major trauma transfusion (PROMMTT) study: comparative effectiveness of a time-varying treatment with competing risks. JAMA Surg 2013;148:127-36.

5. Shakur H, Roberts I, Bautista R, et al.; CRASH-2 trial collaborators. Effects of tranexamic acid on death, vascular occlusive events, and blood transfusion in trauma patients with significant haemorrhage (CRASH-2): a randomised, placebo-controlled trial. Lancet 2010 3;376:23-32.

6. Rowell SE, Barbosa RR, Allison CE, et al. Gender-based differences in mortality in response to high product ratio massive transfusion. J Trauma 2011;71(Suppl 3):S375-9.

7. Rowell SE, Barbosa RR, Diggs BS, et al. Effect of high product ratio massive transfusion on mortality in blunt and penetrating trauma patients. J Trauma 2011;71(Suppl 3):S353-7.

8. Brasel KJ, Vercruysse G, Spinella PC, et al. The association of blood component use ratios with the survival of massively transfused trauma patients with and without severe brain injury. J Trauma 2011;71(Suppl 3):S343-52.


CORRESPONDENCE • CORRESPONDANCE

© 2014 Canadian Medical Association Can J Surg, Vol. 57, No. 5, October 2014 E149

The shorTcoming and deficiency in “aTTempTing primary closure for all open fracTures: The effecTiveness of an insTiTuTional proTocol”

Moola and colleagues1 have done a lot of work on attempting primary closure for all open fractures, and they have found that primary closure for all open fractures is a safe and efficient practice. However, we have some concerns regarding the paper and wish to share them.

First, there was an obvious mistake in the design of the study. As we know, the timing of wound closure in the management of open fractures is very clear both in the orthopedic traumatol-ogy textbook and literature. The open fracture, from Gustilo type I to Gustilo type IIIa, should be treated with pri-mary wound closure. Delayed wound closure is mainly performed in patients with Gustilo types IIIb and IIIc wounds, which always require second-look débridement to assess gross con-tamination. Such complicated open fractures no doubt have higher rates of infection and nonunion.2–5 However, in this study the authors analyzed the fol-lowing patients with open fractures: 152 type I (51.2%), 73 type II (24.6%), 46 type IIIa (15.5%), 13 type IIIb (4.4%) and 13 type IIIc (4.4%) injuries. Of these, types I, II and IIIa accounted for 91.3% of all open fractures. This means that most open fractures for the study should have been treated with primary wound closure. Therefore, the results comparing Gustilo type I, II and IIIa and Anderson type I and II, deter-mining that they had the highest rates of definitive immediate closure, was meaningless, repetitive work. We sug-gest the authors analyze the attempting of primary closure for type IIIb and IIIc open fractures, which remains somewhat controversial in orthopedic traumatology.

Second, certain types of open fracture wound closure need to be

treated with delayed wound closure, which are not subject to Gustilo type restrictions (e.g., wounds with de lay ed presentation [> 12 h] or high-risk of anaerobic contamina-tion). Even in the study by DeLong and colleagues2 there were still some Gustilo I and II wounds treated with delayed closure.

Third, the authors claimed that the only published prospective study evalu ating wound closure protocol for open fractures is by Rajasekaran and colleagues.3 How-ever, we are aware of at least 2 pub-lished prospective articles in the literature.6,7

Yueju Liu, MD Yingze Zhang, MD Third Hospital of Hebei Medical University Shijiazhuang, P.R. China Key Orthopaedic Biomechanics Laboratory of Hebei Province Shijiazhuang, P.R. China

DOI: 10.1503/cjs.007314

References

1. Moola F, Carli A, Berry GK, et al. At tempting primary closure for all open fractures: the effectiveness of an institu-tional protocol. Can J Surg 2014;57:E82-8.

2. DeLong WG, Born CT, Wei SY, et al. Aggressive treatment of 119 open fracture wounds. J Trauma 1999;46:1049-54.

3. Rajasekaran S, Dheenadhayalan J, Babu JN, et al. Immediate primary skin closure in type-III A and B open fractures: results after a minimum of five years. J Bone Joint Surg Br 2009;91:217-24.

4. Rajasekaran S. Early versus delayed clo-sure of open fractures. Injury 2007; 38:890-5.

5. Shanmuganathan R, Kanna PRM, Dheen-adhayalan J. Open injuries of limbs. In: Mercer’s Textbook of Orthopaedics and Trauma. 10th ed. London (UK): Hodder Arnold; 2012:247-57.

6. Anglen JO, Gainor BJ, Simpson WA, et al. The use of detergent irrigation for muscu-loskeletal wounds. Int Orthop 2003; 27:40-6.

7. Chen SH, Wei FC, Chen HC, et al. Emergency free-flap transfer for recon-struction of acute complex extremity wounds. Plast Reconstr Surg 1992;89:882-8, discussion 889-90.

auThor response

We are happy to address your con-cerns with our paper.

You have the following 3 concerns:1. You feel there is no timing debate.2. Some wounds mandate delayed

closure.3. We did not quote the appropriate

papers.1. Timing is still controversial. We

felt that there was enough evidence in the literature to start an institutional protocol. Reviewers still feel that we are too radical with our protocol. On average this is not a design flaw, but rather an attempt to answer a real question in North America: “Can you close open fractures?”. The inclusion of all grades is a review of a system protocol change, not a case-by-case dictation of whether to close or not. The paper is as much a review of a protocol implementation — whether it was successful and whether all sur-geons followed — as it is a review of what happens with these patients.

2. Contaminated wounds and old wounds underwent the same protocol; excision of all contaminated areas con-verted the wound to a clean wound. The protocol did not forbid second looks, and patients were allowed to be taken back to the operat ing room for débridement. As long as the skin was closed initially, they fell in the primary closure group.

3. At the time of the initiation of the protocol, the quoted paper by Benson and colleagues1 was the only prospective paper addressing this sub-ject matter. This is the paper we quote in our design consideration.

Thank you so much for your letter; it is always great to have people read your work so keenly.

Edward J. Harvey, MD, MSc Professor of Surgery, McGill University Michal and Renata Hornstein Chair in Sur-gical Excellence, Chief of Orthopaedic Trauma Montreal General Hospital Montréal, Que.

CORRESPONDANCE

E150 J can chir, Vol. 57, No 5, octobre 2014

DOI: 10.1503/cjs.008114

Reference

1. Benson DR, Riggins RS, Lawrence RM, et al. Treatment of open fractures: a prospective study. J Trauma 1983;23:25-30.

regarding “facTors affecTing The relaTive age effecT in nhl aThleTes”

I read with interest your recent article in the Canadian Journal of Surgery1 in which you report that a small effect was found in relative age effect (RAE) of birth month when the year was divided chronologically in 2 6-month blocks. As I read it, 2 questions arose.

The article reports the height and weight of players. Was this information characterizing players for that season part of the NHL roster? If so, I wonder if you con-sidered using the height, weight and time of drafting and your opinion on their potential effect.

Second, do the other jurisdictions from which NHL players originate share the same birth month–related categorization policies as Canada does in the early years of play? I won-der if that could explain the lack of identified RAE effect you found.

Thank you for informing the dis-cussion on this topic.Pierre Guy, MD, MBA Associate Professor Department of Orthopedics University of British Columbia Vancouver, BC

DOI: 10.1503/cjs.006714

Reference

1. Parent-Harvey CI, Desjardins C, Harvey EJ. Factors affecting the relative age effect in NHL athletes. Can J Surg 2014;57:157-61.

auThor response

Thank you for taking the time to share your questions.

Regarding the height and weight of players, the data for height and weight were obtained for the season itself. We used this data for 2 reasons: (1) the players are in the NHL because of their current fitness and physical attri-butes, not the attributes they were drafted with, and (2) this information was most readily available and verified.

Regarding other jurisdictions, although this information is not read-ily available, other jurisdictions prob-ably do not have the same narrow and restrictive draft conditions that cause an RAE. We discuss in the article why the RAE happens in some sports and not others worldwide. Pavel Datsuk has stated publicly that if he had been in the Canadian system as a youth he would never have been drafted. That would have been a real loss!

Thank you for your questions. I hope this response answers your concerns.C. Parent-Harvey Montréal, QC

DOI: 10.1503/cjs.009214

medical sTudenT–run educaTion: The nexT sTeps

The recently published paper by Li and colleagues1 offers interesting insights into the potential for med-ical student–run medical education. The medical student–run provision was popular and the researchers were able to show significantly more interest statistically in surgical careers in the intervention group. How ever, the researchers are also correct that further qualitative an alysis of their data should prove useful. The limited qualitative data that they have provided are tanta-lizing. The learners felt that the senior medical students were good role models and clearly felt more empower ed to ask them questions. Conversely, the teaching staff was perceived as being more cutting- edge, albeit limited by staff time constraints. It would likely prove

fruitful if further qualitative research could delve into these thoughts and reflections. Such qualitative research is unlikely to find that one form of education is better than another, but it might tease out the exact out-comes that are most effectively and efficiently achieved with student-delivered and staff-delivered learn-ing. A learning package could then be put together, taking the best fea-tures of both forms of delivery. This package could then be evaluated.

Another point of note is that the researchers understandably concen-trated on the learner outcomes; how-ever, it would be interesting also to hear the feedback of the student edu-cators. It would be interesting to know whether they felt positive about the experience, whether they consolidated their own know ledge and skills by teaching others, and whether they developed teaching skills themselves. This would be a secondary but still worthwhile out-come. As soon as students graduate and become doctors, they are auto-matically expected to begin teaching juniors, so any experience that they can obtain as undergraduates would likely prove useful. Many of the teaching skills that they develop are also transferable skills (e.g., commu-nication and presentation skills). These are yet more reasons to encourage the involvement of stu-dents in the teaching process.Kieran Walsh, MBBCh, FRCPI BMJ Publishing Group, BMJ Learning BMA House London, United Kingdom

DOI: 10.1503/cjs.006514

Reference

1. Li JZ, Chan SC, Au M, et al. Review of a medical student-run surgery lecture series and skills lab curriculum. Can J Surg 2014;57:152-4.

a noT-so-sysTemaTic review

In evaluating Ebrahim and colleagues’ meta-analysis,1 which compared low-

CORRESPONDENCE

Can J Surg, Vol. 57, No. 5, October 2014 E151

intensity pulsed ultrasound (LIPUS) to electrical stimulation for fracture healing, we were disappointed to find several glaring errors and omissions.

Fracture nonunion was improperly defined. Nonunion was defined to include both “possible unions (bridging at 3 cortices) and nonunion (bridging at 2 ≤ cortices),”1 yet bridging at 3 cortices defined a healed fracture in 3 of the 7 LIPUS studies evalu ated (references 32, 37 and 39).2–4 Fractures that had been defined as healed in these 3 LIPUS studies were therefore arbitrarily reclas-sified by Ebrahim and colleagues1 as treatment failures.

Reduced time to radiographic union was considered a “surrogate end point,” yet a survey of 335 orthopedic surgeons concluded that “radiographic outcomes were more important than functional outcomes” in designing clinical trials.5 Overall, 88.1% of sur-geons accepted that nonunion is defined by radiographic and clinical criteria, whereas “return to function” was seen as important by just 29.9%.5

Seminal LIPUS papers were omit-ted. It is possible that simple error accounts for omission of the first ran-domized clinical trial (RCT) to evalu-ate LIPUS. The Heckman study6 evalu ated in preference to the RCT7 is actually an econometric evaluation of tibial fracture. Simple error might also account for why a registry study4 was analyzed instead of an RCT published by the same author in the same year.8 Finally, the only RCT in which LIPUS was used to evaluate delayed union9 was omitted for unspecified reasons.

The selection of studies for analysis was biased. Figure 2 in the meta-analy-sis1 identified 6 biased studies (≥ 5 of 8 categories at high risk of bias). There were 3 biased LIPUS studies and 3 biased ESTIM studies, and these 6 studies should have been excluded. Yet the meta-analysis included all 3 biased LIPUS studies (references 37, 39 and 41),3,4,10 while excluding all 3 biased ESTIM studies (references 46, 51 and 55).11–13 A contrast is therefore drawn between the weakest LIPUS papers and the strongest ESTIM

papers, whereas meta-analyses usually strive to avoid such imbalances.

Whether fractures were fresh or nonunion prior to treatment was ignored. Fresh fractures treated with LIPUS were evaluated, as compared to nonunion fractures treated with ESTIM. Of the LIPUS papers evalu-ated, 6 of 7 were about fresh fracture; of the ESTIM papers evaluated, 5 of 8 were about nonunions. Normal healing is expected in fresh fractures; no sponta-neous healing at all is expected in non-unions. Thus, any impact of LIPUS would be hard to document, whereas even a minor impact of eStim should be quite obvious.

We believe these problems invali-date the effort of Ebrahim and col-leagues to produce a clinically useful meta-analysis.

Peter Heeckt, MD, PhD Chief Medical Officer Bioventus LLC Durham, NC

Hans Goost, MD Chairman Department of Orthopaedic and Trauma Surgery Krankenhaus Wermelskirchen Wermelskirchen, Germany

Sheldon S. Lin, MD Associate Professor Department of Orthopaedics Rutgers New Jersey Medical School Newark, NJ

Todd O. McKinley, MD Professor of Orthopaedic Surgery Indiana University Indianapolis, IN

Samir Mehta, MD Assistant Professor and Chief Orthopaedic Trauma University of Pennsylvania Philadelphia, PA

Yuko Mikuni-Takagaki, PhD Project Professor Division of Molecular and Cellular Biology of Mineralized Tissues Department of Oral Sciences Kanagawa Dental University Graduate School of Dentistry Yokosuka, Japan

DOI: 10.1503/cjs.009514

References

1. Ebrahim S, Mollon B, Bance S, et al. Low-

intensity pulsed ultrasonography versus electrical stimulation for fracture healing: a systematic review and network meta- analysis. Can J Surg 2014;57:E105-18.

2. Emami A, Petren-Mallmin M, Larsson S. No effect of low intensity ultrasound on healing time of intramedullary fixed tibial fractures. J Orthop Trauma 1999;13:252-7.

3. Leung KS, Lee WS, Tsui HF, et al. Complex tibial fracture outcomes follow-ing treatment with low-intensity pulsed u l t rasound. Ultra s ound Med B i o l 2004;30:389-95.

4. Mayr E, Frankel V, Ruter A. Ultrasound: an alternative healing method for non-unions? Arch Orthop Trauma Surg 2000;120:1-8.

5. Bhandari M, Fong K, Sprague S, et al. Variability in the definition and perceived causes of delayed unions and nonunions: a cross-sectional, multinational survey of orthopaedic surgeons. J Bone Joint Surg Am 2012;94:e109.

6. Heckman JD, Sarasohn-Kahn J. The eco-nomics of treating tibia fractures: the cost of delayed unions. Bull Hosp Jt Dis 1997;56:63-72.

7. Heckman JD, Ryaby JP, McCabe J, et al. Acceleration of tibial fracture-healing by non-invasive, low-intensity pulsed ultra-sound. J Bone Joint Surg Am 1994; 76A:26-34.

8. Mayr E, Rudzki MM, Rudzki M, et al. Does pulsed low-intensity ultrasound accelerate healing of scaphoid fractures? Handchir Mikrochir Plast Chir 2000; 32:115-22.

9. Schofer MD, Block JE, Aigner J, et al. Improved healing response in delayed unions of the tibia with low-intensity pulsed ultrasound: results of a randomized sham-controlled trial. BMC Musculoskelet Disord 2010;11:229.

10. Strauss E, Ryaby JP, McCabe J. Treatment of Jones’ fractures of the foot with adjunc-tive use of low-pulsed ultrasound stimula-tion. J Orthop Trauma 1999; 13: 310.

11. Betti E, Marchetti S, Cadossi R, et al. Effect of stimulation by low-frequency pulsed electromagnetic fields in subjects with fracture of the femoral neck. In: Bersani F, editor. Electricity and magne-tism in biology and medicine. New York (NY): Kluwer Academic/Plenum; 1999: 853-855.

12. Poli G, Dal Monte A, Cosco F. Treat-ment of congenital pseudarthrosis with endomedullary nail and low frequency pulsing electromagnetic fields: a con-trolled study. Electromagn Biol Med 1985;4:195-209.

13. Wahlström O. Stimulation of fracture healing with electromagnetic fields of extremely low frequency (EMF of ELF). Clin Orthop Relat Res 1984; (186):293-301.

CORRESPONDANCE

E152 J can chir, Vol. 57, No 5, octobre 2014

The auThors respond

Dr. Heeckt and colleagues have raised a number of potential issues with our systematic review and network meta-analysis on low-intensity pulsed ultra-sound (LIPUS) versus electrical stimu-lation for fracture healing.1

Their first concern was that “frac-ture nonunion was improperly defined,” specifically with respect to our definition of fracture union only including bridging at 4 cortices, and our decision to merge possible union (bridging at 3 cortices) and nonunion (bridging at ≤ 2 cortices) into 1 cat-egory (nonunion). To facilitate our standard meta-analyses and network meta-analysis, we dichotomized the outcome of fracture union to create a common outcome measure across trials. Our decision to merge possible union and nonunion into 1 category was informed by an experienced orthopedic surgeon who was blinded to the eligible studies in our review. This description was provided in the “Synthesis of results” subsection in the Methods section of our review.

Their second concern was that “reduced time to radiographic union was considered a surrogate end point.” Dr. Heeckt and colleagues cited a survey,2 led by one of us (M.B.), that found orthopedic sur-geons consider radiographic out-comes to be more important than functional outcomes when designing clinical trials. Our systematic review specifically considered patient- important outcomes (Table 4, Ques-tion C in the systematic review). Return to functioning is a patient-important outcome, whereas radio-graphic outcomes are an indirect measure of functional recovery. This is an important distinction for read-ers, as improvements in surrogate outcomes may not translate to com-mensurate improvements in function. A systematic review by Busse and col-leagues3 on the effectiveness of LIPUS for fracture healing found that although there was low-quality evidence from 6 trials to suggest that

LIPUS was effective in reducing time to radiographic healing, only 4 trials directly assessed functional recovery, with 3 showing no effect.

Their third concern was that “sem-inal LIPUS papers were omitted.” Our extraction and analysis did include data from the trials they cited as being omitted,4,5 but the cited ref-erences were incorrect. Thank you for bringing this to our attention; we have now provided the correct refer-ences to CJS.

Their fourth concern was that “the selection of studies for analysis was biased” and that studies with high risk of bias should have been excluded. Although these studies suffer from high risk of bias in multiple com-ponents on the Cochrane Risk of Bias tool, this does not warrant exclusion of the studies simply on the basis of risk of bias. It is inappropriate to exclude studies from meta-analyses based on arbitrary thresholds for study quality without first conducting subgroup analyses to explore whether or not treatment effect estimates dif-fer among trials with low risk of bias and trials with high risk of bias.6 We planned to perform such subgroup analyses to explore components of risk of bias as a factor to explain hetero geneity in treatment effect esti-mates, and we included this in our review as follows: We generated the following a priori hypothesis to explain variability between studies: studies with greater risk of bias will have larger effects than studies with lower risk of bias. This sub-group analysis was completed only on a risk of bias component × component basis if there was considerable variability within the risk of bias component. On consulting with a methodolo-gist, we performed subgroup analyses only when there were at least 5 studies to avoid high risk of spurious subgroup findings.1

Given that each of our analyses consisted of fewer than 5 trials, we were underpowered to perform sub-group analyses to explore risk of bias as a factor to explain heterogeneity in effect estimates. To provide transpar-ency to readers, we provided a risk of bias summary and a GRADE sum-mary of findings table (Table 2 and 3 in the systematic review1). Addition-

ally, the ESTIM studies (with multi-ple components of high risk of bias) were not excluded from our review because of risk of bias, but because they did not report the outcome of interest (union rates) for our analysis. This was described in our Results sec-tion as follows: Eight trials evaluating LIPUS (7 fresh fracture and 1 nonunion populations), and 7 trials evalu ating ESTIM (3 fresh fracture and 5 nonunion populations), reported union rates as one of their outcomes and were used in the network meta-analyses.1

Their final concern was the claim that “whether fractures were fresh or nonunion prior to treatment was ignored.” This distinction was not ignored in our review and we sep-arated these 2 types of fractures in our analyses. This was stated in our objec-tives as follows: (...) to systematically review the LIPUS and ESTIM literature and perform a network meta-analysis of these 2 treatments for accel-erating fracture healing in both fresh fracture and nonunion populations.1

We also provided the results sep-arately for these 2 populations — we found that in patients with a fresh frac-ture, there was a nonsignificant benefit of LIPUS versus standard care and ESTIM on union rates at 6 months, and in patients with an existing nonunion or delayed union, we found a nonsignifi-cant benefit of ESTIM over standard care on union rates at 3 months.

We thank Dr. Heeckt and col-leagues for their interest in our paper and continue to believe our findings represent a careful and systematic review and analysis of the literature. Ultimately, the goal of our review was to shed light on knowledge gaps and we stand by our recommendation for large head-to-head trials with safeguards against bias that assess patient- important outcomes to con-firm or refute the role of bone stimula tion devices for fracture heal-ing in either fresh fracture or non-union populations.

Shanil Ebrahim, MSc, PhD Department of Clinical Epidemiology & Biostatistics

CORRESPONDENCE

Can J Surg, Vol. 57, No. 5, October 2014 E153

Department of Anesthesia McMaster University Hamilton, Ont. Department of Medicine Stanford University Stanford, Calif.Brent Mollon, MD Division of Orthopaedics University of Toronto Toronto, Ont.Sheena Bance, MSc Department of Applied Psychology and Human Development Ontario Institute for Studies in Education University of Toronto Toronto, Ont.Jason W. Busse, DC, PhD Department of Anesthesia Department of Clinical Epidemiology & Biostatistics McMaster University Hamilton, Ont.

Mohit Bhandari, MD, PhD

Division of Orthopaedic Surgery

Department of Clinical Epidemiology & Biostatistics McMaster University Hamilton, Ont.

DOI: 10.1503/cjs.011014

References

1. Ebrahim S, Mollon B, Bance S, et al. Low-intensity pulsed ultrasonography versus electrical stimulation for fracture healing: a systematic review and network meta-analysis. Can J Surg 2014;57:E105-18.

2. Bhandari M, Fong K, Sprague S, et al. Variability in the definition and perceived causes of delayed unions and nonunions: a cross-sectional, multinational survey of

orthopaedic surgeons. J Bone Joint Surg Am 2012;94:e109.

3. Busse JW, Kaur J, Mollon B, et al. Low intensity pulsed ultrasonography for frac-tures: systematic review of randomised controlled trials. BMJ 2009;338:b351.

4. Heckman JD, Ryaby JP, McCabe J, et al. Acceleration of tibial fracture-healing by non-invasive, low-intensity pulsed ultra-sound. J Bone Joint Surg Am 1994;76A:26-34.

5. Mayr E, Rudzki MM, Rudzki M, et al. Does pulsed low-intensity ultrasound accelerate healing of scaphoid fractures? Handchir Mikrochir Plast Chir 2000;32:115-22.

6. Dechartres A, Altman DG, Trinquart L, et al. Association between analytic strat-egy and estimates of treatment outcomes in meta-analyses. JAMA 2014; 312: 623-30.

CAREER/CLASSIFIED ADVERTISING/CARRIÈRES ET ANNONCES CLASSÉES

The Canadian Journal of Surgery is pleased to accept career/classified advertisements. The deadline is 1 month before issue date.

Rates: Display ads: 1 page $1200; 2/3 page $900; 1/2 page vert/horiz $800; 1/3 page $650; 1/4 page $500; 1/6 page $400. Word ads: $120 for the first 40 words or less, additional words $1.20 each (additional $25 for frame). Special Display under 100 words, 55 × 55 mm, $205. $20 charge (first insertion only) for CJS confidential reply box numbers.

VISA, MASTERCARD AND AMERICAN EXPRESS ACCEPTED.

Advertisements should be sent to: Journal Advertising, Canadian Journal of Surgery, 1867 Alta Vista Dr., Ottawa ON K1G 5W8; tel 800 663-7336 or 613 731-8610 x2107/2041; fax 613 565-7488; email [email protected]

Send all box number replies to: Box . . . , Canadian Journal of Surgery, 1867 Alta Vista Dr., Ottawa ON K1G 5W8.

The Ontario Human Rights Code prohibits discriminatory employ ment advertising.

Le Journal canadien de chirurgie accepte volontiers les annonces sur les carrières et annonces classées. Celles-ci doivent être reçues au JCC au plus tard 1 mois avant la date de parution.

Tarifs: Grand format: 1 page 1200 $; 2/3 page 900 $; 1/2 page vert/horiz 800 $; 1/3 page 650 $; 1/4 page 500 $; 1/6 page 400 $. Mot des annonces: 120 $ jusqu’à 40 mots et 1.20 $ par mot supplémentaire (25 $ pour encadrement au trait). Encadré spécial jusqu’à 100 mots, 55 × 55 mm, 205 $. L’emploi d’une boîte-réponse confidentielle au JCC donne lieu à la perception d’un supplément de 20 $ (pour la première insertion seulement).

VISA, MASTERCARD ET AMERICAN EXPRESS ACCEPTÉS.

Le texte des annonces doit être adressé à : Annonces publicitaires, Journal canadien de chirurgie, 1867, prom. Alta Vista, Ottawa (Ontario) K1G 5W8; tél 800 663-7336 ou 613 731-8610 x2107/2041; fax 613 565-7488; courriel [email protected]

Veuillez faire parvenir les réponses au numéros de boîtes à l’adresse suivante : Boîte . . . , Journal canadien de chirurgie, 1867, prom. Alta Vista, Ottawa, (Ontario) K1G 5W8.

Le Code des droits de la personne de l’Ontario interdit la dis crimi nation dans la publicité relative à l’emploi.

ACADEMIC MOHS SURGEON CLINICIAN-SCHOLAR

Queen’s Department of Medicine, Division of Dermatology, is seeking a Mohs surgeon to join their group.

This is a full-time academic position. The incumbent will assist the Division in fulfilling its Clinical and Academic mission within the Department of Medicine.

Clinical responsibilities include Mohs surgical cases and associated skin cancer clinics. Limited on-call general dermatology service for urgent cases may be required.

The incumbent will participate in undergraduate and post-graduate teaching, as well as continuing medical education. Teaching will be a combination of clinical/surgical teaching for undergraduate and postgraduate learners as well as some lectures. The position will have 15% time protected for academic activity. Protected time for research is possible for candidates that have demonstrated a program of basic or clinical research.

Members of the Department of Medicine enjoy a competitive compensation package, including a generous benefit plan. Academic rank will be commensurate with experience.

Candidates must be eligible for licensure in the Province of Ontario and preference will be given to those who either hold or are eligible for certification by the Royal College of Physicians and Surgeons of Canada in Internal Medicine or the American Board of Specialties.

One of Canada’s leading universities, Queen’s has a long reputation for academic excellence, research, and a diverse and vibrant learning environment. With its strong tradition of public service, the University has helped to shape Canadian values and policies, educating notable political and cultural figures. Queen’s is located in the heart of the community in historic Kingston, midpoint between Montreal, Toronto and Ottawa, the nation’s capital.

Applications, which are to include a letter summarizing expertise, qualifications and accomplishments relevant to the position together with a curriculum vitae and the names and full contact information of three referees, are to be directed to:

Dr. S.L. Archer, Professor and Head, Department of Medicine c/o Jennifer Andersen

Etherington Hall, 94 Stuart Street Kingston, Ontario K7L 3N6

Email [email protected]

Review of applications will commence September 15, 2014 and will continue until the position is filled.

Queen’s is committed to employment equity and diversity in the workplace and welcomes applications from women, visible minorities, Aboriginal people, persons with disabilities, and persons of any sexual orientation or gender identity. All qualified candidates are invited to apply; however, Canadian citizens and permanent residents will be given priority.

The University will provide support in its recruitment processes to applicants with disabilities, including accommodation that takes into account an applicant’s accessibility needs. If you require accommodation during the interview process, please contact: Mrs. Jennifer Andersen, email [email protected]

S-7

59

ACUTE CARE EMERGENCY SURGERY(ACES) FELLOWSHIP

University of Alberta, Edmonton AB CANADAOne-year surgical fellowship starting July 1, 2015 offeringexpertise in the management, care and operative techniquesinvolved in emergency/acute care surgery. Opportunitiesexist for individualized research and elective experiences.Applications should consist of a current curriculum vitae andthree letters of reference (two must be from surgeons) forreceipt by October 30, 2014. Please submit to:

Dr. S. Widder2D4.27 Walter Mackenzie Centre

University of Alberta Hospital, 8440 – 112 Street NWEdmonton, AB CANADA T6G 2B7

Tel 780 407-2005 • Fax 780 407-2144

S-760

classifiedcjs-oct14.indd 1 14-09-16 1:59 PM

When it comes to your health, more medical tests, treatments and procedures are not always better. In fact, sometimes they’re unnecessary. Find out when you need medical tests, treatments and procedures — and when you don’t.

Talk with your doctor or visit ChoosingWiselyCanada.org

@ChooseWiselyCA

Choosing Wisely Canada. A healthy conversation.

choosing wisely-e.indd 1 13.06.2014 12:12 PMcovercjs-oct14.indd 2 14-09-16 11:00 AM

choosing wisely canada. a healthy...

Documents