Medycyna Wet. 2007, 63 (12)1564

Praca oryginalna Original paper

Diaphragmatic hernia refers to a protrusion formedby abdominal viscera into the thoracic cavity throughabnormal openings in the diaphragm (3). It is knownthat most of diaphragmatic hernia cases (93%) are cau-sed by trauma while only a small portion of the casesdevelop spontaneously. The diaphragmatic muscle isfrequently torn along the costal edges of the diaphragmat the ventral of the esophagus hiatus. The size andlocation of the slit in the muscle of the diaphragmdetermine which organs will pass into the thoraciccavity or become incarcerated in it. The abdominalorgans that pass through and become incarcerated mayhave a varying degree of venous obstruction and con-gestion. The liver may produce an excessive amountof fluid which is transudat and extracellular in nature(8).

Traffic accidents with motor vehicles are the mostfrequent cause of traumatic hernias. However, anystrong blow or impact such as falling from a higherplace may also cause a diaphragmatic hernia. Thereis no known predisposition of race or genus for theoccurrence of this type of hernia in cats. However, mostof the herniated animals are at young ages (1-2-years--old), indicating a possible age predisposition. Theprogress of the disease may vary from hours to years.The reason for such a large variation is that the diseasemay not be diagnosed for a long period of time afterthe traumatic incident (7, 8).

Traumatic diaphragmatic hernias often occurs incats. The most frequently observed congenital typeof hernia is peritoneopericardial hernia (2, 3, 5, 10). Theanimals with diaphragmatic hernia are usually brought

to a clinic under shock associated with tachycardia,tachypnea/dyspnea, pale mucosal membranes, andoligourea. Cardiac arrhythmia is frequently observedand known as an important cause of morbidity. Otherclinical findings vary depending on the organ(s) her-niated. They may include gastrointestinal, respiratory,and cardiovascular symptoms. The liver is the mostfrequently herniated organ and may result in hydro-thorax. The cause of hydrothorax includes venousobstruction and the squeezing of the organ. If a largeportion of the stomach and intestines are herniated,the animal may look emaciated (3-5, 8).

Definitive diagnosis requires radiographic examin-ation. If there is a pleural effusion, thoracosynthesismust be conducted before the radiography. Loss of dia-phragmatic line and cardiac shadow, dorsal or lateraldisplacement of lung surfaces, presence of gas in thethoracic cavity and presence of small intestine orstomach filled with barium sulfate are characteristicsof the diagnosis. In general, positive contrast celio-graphy may assist in diagnosis (1, 3-5, 9). A diaphrag-matic slit should be stitched by simple continuousstitches using an absorbable material such as polydiaxo-none or non-absorbable material polypropylene (3, 7, 8).

The aim of this study was to determine the optimalanesthetic and surgical procedures in feline diaphrag-matic herniations.

Material and methodsA total of 44 cats (20 male, 24 female), at ages from

2 months to 3 years of age in different breeds were utilized.Initially the cats brought to our clinic after a trauma or with

Diaphragmatic hernia in cats: 44 casesKURSAT OZER, OZLEM GUZEL, YALCÝN DEVECIOGLU, OZGUR AKSOY*

Department of Surgery, Faculty of Veterinary Medicine, Istanbul University, 34320, Avcilar, Istanbul/Turkey*Department of Surgical, Faculty of Veterinary Medicine, Kafkas University, 36040, Kars-Turkey

Ozer K., Guzel O., Devecioglu Y., Aksoy O.Diaphragmatic hernia in cats: 44 Cases

SummaryDiaphragmatic hernia is one of the most frequently observed injuries caused by trauma in cats. Study

materials were a total of 44 cats (20 male, 24 female), at different ages (2-months-old to 2-3-years-old) fromvarious breeds. Following direct radiography, positive-contrast radiography was also taken to confirmthe diagnosis. General anesthesia was induced using 5% isoflurane inhalation. Following entubation, theanesthesia was continued using 1.5-2% isoflurane inhalation by a nonrebreathing system with a pediatriccircle. When the repair was about to be completed, positive pressure was increased for treating atelectasis.The mortality rate in traumatic diaphragmatic hernia cases was found to be 6.8% at the end of the study.It was concluded in this study that the success of the surgery may be increased by effective anestheticprocedures.

Keywords: cat, diaphragmatic hernia

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a complaint of respiratory difficulty were physically exa-mined. Following direct radiography, positive-contrastradiography was also conducted to confirm the diagnosis(fig. 1a-b, 2a-b). After the definitive diagnosis was perfor-med, routine heamogram and biochemical analyses wereconducted and the general condition of the patients that didnot require urgent care was stabilized.

A haemogram was conducted in 44 cases. Erythrocyte(RBC), haemoglobin (HGB), haematocrit (HCT), leuko-cyte (WBC) and thrombocyte (PLT) levels of the cases wereevaluated. Biochemical tests were conducted in 12 of thesecases as well. Aspartat aminotransferase (AST), alanineaminotransferase (ALT), gamma-glutamiltransferase (GGT)and creatine kinase (CK) levels of the cases were evalu-ated.

Oxygen was given for 10 min at the preanesthetic periodusing a mask. Meanwhile, venous access to intravenousinjection was opened without causing irritation. Followingthis, general anesthesia was induced using 5% isoflurane(Forane® Likid, Abbott Laboratories, Istanbul, Turkey) in-halation. After entubation, the anesthesia was maintainedusing 1.5-2% isoflu-rane inhalation bya nonrebreathing sys-tem with a pediatriccircle (BOC-BoyleInternational, Tur-key). The patientswere prepared forsurgery under gene-ral anesthesia (fig. 3).Abdominal regionsof the patients wereprepared for thesurgery accordingto aseptic surgicalprinciples after thepositioning of theanimals upwards.The abdominal cavi-ty was excised bymedian laparatomy.At this stage an assi-sted-ventilation wasinitiated. The her-niated organs were

pulled back usinga wet-gauze. Theslit on the dia-phragm was stit-ched by continuousstitches using 2/0 or3/0 polyglactin 910suture (Vicryl®--Ethicon, Edin-burgh, UK) depen-ding on the size ofthe cat. During therepair of the dia-phragmatic slit, theassisted ventilationwas continued ata 1 sec intervalusing 30% capacityof the lungs. Whenthe repair wasabout to be comple-ted, positive pres-sure was increasedto treat atelectasis.After elimination of

atelectasis, the final stitch was inserted when the lungs wereat complete expiration and then the pressure was de-creased. The opening of the laparotomy was closed accor-dingly. Isoflurane inhalation was ceased and oxygen wasgiven until spontaneous respiration and a swallowingreflex began. Postoperative radiography was taken afterextubation (fig. 4). During the postoperative stage, Carpro-fen (Rimadyl-Pfizer Limited, UK) was given at 4 mg/kgdose as an analgesic and antibiotherapy was applied for5 days. The stitches were removed 7-8 days after the surgery.

Fig. 1a. A laterolateral direct radiography of a 2-year-old fe-male cat of mixed-breed

Fig. 1b. A direct ventrodorsal radiogra-phy of the same cat in figure 1a

Fig. 3. Inhalation anaesthesia with a pediatric circle in a cat

Fig. 2a. A laterolateral positive-contrast celioghraphy of thesame cat in fig. 1a-b

Fig. 2b. A ventrodorsal positive-con-trast celioghraphy of the same cat

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Results and discussionThe mean age of the cats was 10 months and varied

from 2 months to 3 years. Twenty four of the 44 catswere female while the remaining 20 were male. Thefrequency of occurrence of diaphragmatic hernia wasthe highest in cross breed cats (39 cases) followed byPersian (3 cases) and Siamese (2 cases) cats.

The cause of the hernia was mostly trauma. In 4 ofthe cases, there were also fractures due to trauma(2 humerus, 1 femur, 1 tibia). All of the patients werebrought to our clinic with the complaint of respiratorydifficulty. Definitive diagnosis was made by the ra-diographic examination of the thoracic cavity. Otherfindings were dry-cough, anorexia, decreases in lungand heart sounds by auscultation, and the thinnerappearance of the abdomen of the animals comparedto the normal size of the cat�s abdomen.

In the laterolateral (LL) radiographies of the thorax,there were disappearances of the diaphragmaticborder, presence of consolidation (pleural effusion) in12 cases, and intestine with gas noted in 4 cases. Thedefinitive diagnosis was made by positive contrastcelioghraphy. In celiography it was observed thatiodine contrast substance passed to the thoracic cavityseveral minutes after intra abdominal administration.The site of the hernia was determined by ventro--dorsal (VD) radiography.

Haemogram results indicated that anemia was pre-sent in very young cats (2-6 months and in both of thegenders). Following biochemical analysis, an increasewas determined in the levels of the liver enzymes AST,ALT and GGT, in 5 (3 females, 2 males) of the 12cases. In the remaining 7 (4 females, 3 males) acutecases, on the other hand, a rise in CK levels was noteddue to the destruction of muscle tissue.

It was observed that the liver was herniated in all ofthe cases. Additionally, stomach, omentum, and smallintestines were among the most frequently herniatedorgans. The slit of the diaphragm was at the dia-phragm-costa attachment site in 30 cases (right site in17, left site in 13 cases) and at the hiatus level in 14cases. Thoracic fluid accumulation was noted in 12 ofthe cases due to venous stasis.

Three of the cases were lost during the operation,two of these deaths were due to a failure in removingthe excessive secretion from the respiratory system andthe other due to a slit of the lungs caused by the appli-cation of too much pressure during the elimination ofatelectasis.

Diaphragmatic hernia is one of the most frequentlynoted cases caused by trauma in cats (3, 5, 7, 8, 10). Inthe present study, congenital hernia was not observed.In all cases, however, a history for trauma was exi-stent or signs of a recent trauma such as echimosis,wounds, and fractures were noted during the physicalexamination of the animals.

Although no known predilection was reported fordiaphragmatic hernia in cats (3, 7), a great majority ofour cases were cross breed cats (39 cases). As the gen-ders of the patients were evaluated, it was observedthat the number of the female cats (24) was slightlyhigher than the male cats (20). The disease was morecommon among younger aged cats (10 months of ageon average) which is consistent with the previous lite-rature (3, 5, 8).

Sick animals with a history of trauma and a compla-int of respiratory difficulty should be evaluated for dia-phragmatic hernia since these are the common symp-toms for this disease (3, 5, 8). Radiographic exami-nation, especially positive contrast celioghraphy, isstrongly recommended for a definitive diagnosis (1, 3,4, 8-10). However, it should be remembered thata diagnosis based on the passage of the contrastingsubstance to the thoracic cavity might be misleadingif there are adhesions. In our study, we have onlynoted this in one case (fig. 5a-b).

Fig. 4. A laterolateral postoperative radiography of the samecat as in fig. 1

Fig. 5b. Positive contrast celiography of the same cat shownin fig. 5a

Fig. 5a. A case of hernia diaphragmatica (laterolateral view)

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The liver is the most frequently herniated organ andusually considered responsible for hydrothorax cau-sed by the venous stasis of the organ. Fluid accumula-tion in the thoracic cavity was seen in 12 of the 44cases in the current study. The increase in AST, ALTand GGT levels noted in 4 cases was thought to bea result of the liver being under pressure for a longtime due to the chronic nature of the cases.

If the general condition of a patient is stable enoughto allow surgery, the animal should be operated as soonas possible to prevent acute decompensation and po-tential lung edema that may develop postoperatively(3). However, it was reported that surgery within thefirst 24 h without stabilizing the patient may result ina higher mortality rate. Preoperative oxygen inhala-tion is essential for myocardial oxygenisation and theprevention of acidosis (3).

Use of prednisolon is recommended for the preven-tion of reexpansion edema (3). As the use of predniso-lone was only a recommendation and since it wasthought that this medication could have a detrimentaleffect on the healing of the wound, it was not conside-red to be suitable for use in this study. In this study,where thorax drainage was not essential (2, 3, 8) theprocedure was not carried out post-operatively in anyof the cases. No complication was observed within thefollow up examinations of the first year.

Since cats with diaphragmatic hernia exhibit respi-ratory depression, they should not be anesthetized bycombinations of preanesthetic (xylazine) and anesthe-tic (barbiturates) that may depress the respiratory sys-tem. Although the authors do not recommend usingface masks for anesthetic induction (3, 6, 10), we have

not encountered any difficulty or complications. Mor-tality rates in traumatic diaphragmatic hernia cases varyfrom 12 to 48% (3, 7, 8). The mortality rate was 6.8%in this study, which is lower than the average.

As a result, in stabilized cat patients with diaphrag-matic hernia, the success of the surgery may be in-creased by anesthesia initiated by mask induction fol-lowed by the use of isoflurane via entubation.

References1.Biler D. S.: Imaging techniques in the clinical evaluation of thoracic disease.

Proc. of XX. Congress World Small Animal Vet. Assoc., Yokohama, Japan1995, p. 300-305.

2.Crowe D. T., Archibald J.: Abdominal wall and cavity, [in:] Archibald J.,Catcott E. J.: Canine and Feline Surgery. American Veterinary PublicationsInc., California 1984, p. 52-89.

3.Fossum T. W.: Surgery of the lower respiratory system: pleural cavity anddiaphragm, [in:] Fossum T. W.: Small Animal Surgery. Mosby, St. Louis 1997,p. 675-687.

4.Hosgood G.: Thoracic wall and cavity, [in:] Harari J.: Williams&WilkinsSmall Animal Surgery. Philadelphia 1996, 110-114.

5.Levine S. H.: Diaphragmatic hernia. Vet. Clin. North Am. Small Anim. Pract.1987, 17, 411-430.

6.Liptak J. M., Bissett S. A., Allan G. S., Zaki S., Malik R.: Hepatic cysts incar-cerated in a peritoneopericardial diaphragmatic hernia. J. Feline Med. Surg.2002, 4, 123-125.

7.Minihan A. C., Berg J., Evans K. L.: Chronic diaphragmatic hernia in 34dogs and 16 cats. J. Am. Anim. Hosp. Assoc. 2004, 40, 51-63.

8.Schwarts A., Schunk C. J. M.: The thorax, [in:] Harvey C.: Small AnimalSurgery. Newton, C. D., Schwarts A., Lippincott J. B. Co., Philadelphia 1990,p. 243-248.

9.Stickle R. L.: Positive-contrast celiography (Peritoneography) for the diagno-sis of diaphragmatic hernia in dogs and cats. J. Am. Vet. Med. Assoc. 1984,185, 295-298.

10.White J. D., Tisdall P. L. C., Norris J. M., Malik R.: Diaphragmatic hernia ina cat mimicking a pulmonary mass. J. Feline Med. Surg. 2003, 5, 197-201.

Author�s address: Dr. Ozlem Guzel DVM, PhD, Surgery Department,Faculty of Veterinary Medicine, Istanbul University, 34320, Avcilar-Istan-bul/Turkey; e-mail: drozlemguzel@gmail.com, droguzel@istanbul.edu.tr