Percutaneous Nephrolithotomy in Renal Anomaliesof Fusion, Ectopia, Rotation, Hypoplasia,

and Pelvicalyceal Aberration: Uniformity in Heterogeneity

Abdul Majid Rana, MBBS, FRCS (Ed), and Jai Parkash Bhojwani, MBBS

Abstract

Context: Percutaneous nephrolithotomy (PCNL) in renal fusion, ectopia, renal rotational anomalies, renal hy-poplasia, and pelvicaliceal aberration for complex calculi is challenging for fear of inaccessibility, vascular,colonic, and splanchnic injury. We report our experience with 48 such patients.Patients and Methods: From 2002 to July 2007, 48 patients (mean age, 28 years) underwent PCNL for mean stonesize of 39 mm. Fourteen patients had malrotated kidneys, 12 patients had bifid renal pelvis with complete orincomplete double ureter, 10 horseshoe kidneys, 8 hypo plastic kidneys, 3 with crossed fused ectopia, and 1 hadpelvic kidney. After appropriate evaluation, the procedure was performed in one session either in prone orsupine position with or without nephrostomy tube making amendments to the conventional procedure asdeemed necessary befitting the requirements.Results: Complete stone clearance was achieved in 39 patients (81%) after single session of PCNL. Seven patientstreated subsequently with extracorporeal shockwave lithotripsy (SWL) for residual stone also became stone free,achieving final stone-free status of 96%. Three patients had more than one tract creation; 25 patients had thisprocedure in supine position. Mean hospital stay was 3 days (range, 2–7 days). Three patients required trans-fusion, and two had perinephric collection. No incidence of bowel, vascular, and splanchnic injury was recorded.Stone analysis showed calcium oxalate composition in 83% calculi.Conclusion: Universal application of PCNL in all diverse situations like renal fusion, renal ectopia, renal mal-rotation, renal hypoplasia, and pelvicaliceal variations yields comparable results demanding firm resolve andmandatory surgical skill on behalf of the surgeon.

Introduction

Congenital anomalies occur more frequently in theupper urinary tract than in the other organs. These renal

anomalies range from agenesis, hypoplasia, fusion, rotation,ectopia to aberration of pelvicaliceal system, and variations inits blood supply.

Percutaneous nephrolithotomy (PCNL) has established itsmark as the most effective and is sought after treatment forlarge and complex renal stones in normal kidneys with almost82% success rate.1 However, in contemporary literature, re-ports regarding large and complex calculi in anomalous kid-neys treated by PCNL are rare; horseshoe kidneys are the onlyexception. PCNL in horseshoe kidney has a significant edgeover extracorporeal shockwave lithotripsy (SWL), with anoverall success rate of 89%2,3 in large stones.

We present our experience with 48 such patients whichincludes all forms of anomalous kidneys except thoracic

kidney, having symptomatic calculi treated with PCNL,applying desired variations in the patients’ position, andachieving comparable results that propose PCNL as the mosteffective treatment modality for patients suffering from largecalculi in anomalous kidneys.

Patients and Methods

From 2002 to July 2007, 48 patients (36 men and 12 women)(M:F¼ 3:1) suffering from renal stones in anomalous kidneyswere consecutively treated by PCNL for a mean stone size of39 mm (range, 35–52 mm). The mean age of the patients was28 years (range, 21–53 years). Fourteen patients had mal-rotated kidneys, 12 had bifid pelvis with incomplete doubleureter, 3 had complete double moiety, 10 had horseshoekidneys, 8 had hypoplastic kidneys defined as ‘‘a kidney sig-nificantly smaller than the contralateral kidney associated withno pelvicaliceal distortion and shows normal echogenicity

Department of Urology, The Kidney Centre Post Graduate Training Institute, Dow University of Health Sciences, Karachi, Pakistan.

JOURNAL OF ENDOUROLOGYVolume 23, Number 4, April 2009ª Mary Ann Liebert, Inc.Pp. 609–614DOI: 10.1089=end.2007.0430

609

on ultrasound,’’4 3 had crossed fused ectopia, and 1 had pelvickidney.

Fusion, rotational anomalies, and ectopia usually manifestas repeated urinary tract infection in 30% of the patients, andhematuria, palpable mass, and calculus formation are in 20%of the patients and are mainly due to abnormally positionedand distorted uretero pelvic junction, vascular compression,and the presence of dense fibrous tissue causing obstruction toupper ureters.5 Detail characteristics of patients and stones aregiven in Table 1.

Preoperative preparation included routine laboratoryanalysis such as complete blood count, urea, creatinine, andurine culture. Ultrasonography and intravenous urography(IVU) were arranged for all patients. Computed tomography(CT) and isotope scans were performed in relevant cases. Onthe first postoperative day, all patients underwent KUB, ul-trasonography, or both, to assess stone clearance. Dependingon the absence or presence of residual stone, the decision wasmade regarding removal of all tubes and hospital discharge,or arrangement for auxiliary procedures planned. Patientswere followed up in the clinic with plain abdominal X-ray orultrasonography till they could be declared either stone free orwith clinically insignificant residual fragments.

Technique

Retrograde urography and placement of 5F ureteral cath-eter was done in supine position under general anesthesia toopacify and fill the pelvicaliceal system. The dynamic reviewof fluoroscopic visuals was most decisive, to determine thepatient’s ultimate position (supine or prone), point of cuta-neous entry (supra costal or sub costal), choice of calycealpuncture (upper, middle, or lower), and anticipated numberof tracts. Antegrade caliceal access was gained using 18-gaugespinal needle under fluoroscopy, and tract was dilated over0.032-inche guide wire up to 27F with Alken metal dilatorsfollowed by placement of 30F Amplatz sheath through which26F rigid nephroscope (Karl Storz�, Karl Storz GmbH & Co,Tuttlingen, Germany) was introduced. In supine positiononce retrograde urography and placement of ureteral catheterwas achieved, the patient’s torso is placed with complete ex-

tension of both legs, with the side bearing the stone at the edgeof the operating table as this facilitates the optimum workinglength of the Amplatz sheath. The patient’s ipsilateral arm isfolded over the chest to provide maximum working space forthe surgical team, and the contralateral arm is fully extendedand adducted to the patient’s side to accommodate the ‘‘C’’arm of fluoroscope. To improve the lateral accessibility of thekidney, a rolled cloth towel (14 cm long, 7 cm wide, and 7 cmhigh), thick enough to elevate the flank by 208, is placed belowthe ipsilateral flank. This maneuver causes the posterior calixto project more laterally (Fig. 1A, B). It is pertinent to avoid

Table 1. Characteristics of Patients: Types of Anomalous Kidneys (Total 48)

Malrotatedn¼ 14

Bifid pelvisn¼ 12

Horseshoen¼ 10

Hypo plasticn¼ 8

Crossed fusedectopia n¼ 3

Pelvicn¼ 1

Age, years (mean� SD) 33� 7 38� 11 26� 9 41� 12 38� 5 19Mean stone size (mm)

Single stones 45 38 36 35 41 –Presentation of calculi

Pain 6 10 8 8 2 1Hematuria 11 7 6 3 1 1Urinary tract infection (UTI) 3 5 5 2 0 0Palpable mass 0 0 0 0 0 1

Stone locationPelvis 7 6 6 4 2 1Calyx 4 4 2 1 0 0Stag horn 3 2 2 3 1 0

Number of stonesSingle 8 7 3 3 1 0Multiple 3 3 5 2 2 1Stag horn 3 2 2 3 0 0

FIG. 1. (A) Cross section of the body showing lower calixforming 508 angle with operating table in supine position.(B) Flank elevated by 208, lower calix rotates more laterallybecoming perpendicular to operating table.

610 RANA AND BHOJWANI

creating the oblique position, which although appears tomake the posterior calix move laterally but in fact causesfurther medial displacement of the targeted renal calix. This iswhy the rolled cloth towel should neither cross the posteriormidline nor should the operating table be tilted toward thecontralateral side.6

Swiss Pneumatic Lithoclast (E.M.S.�, EMS Medical GmbH,Meersburg, Germany) has been the only stone fragmentationdevice used. Large stone fragments are extracted withgrasping forceps, and remaining stone crush is retrieved usinga water jet generated by size 14F suction catheter connected toa 60-cc catheter-tip syringe filled with normal saline throughthe Amplatz sheath intermittently.

At the conclusion of this procedure, stone clearance wasevaluated fluoroscopically, and if there were no considerableresidual stone burden, insignificant perforation of the collect-ing system, and no significant bleeding, defined as ‘‘persistentbleeding that occurred throughout the procedure and was notalleviated by the tamponade effect of Amplatz sheath,’’7 thesheath was removed and the nephrostomy wound closed withtwo hemostatic sutures using size 1 Prolene� (Ethicon Ltd.,Bankhead Ave., Edinburgh, United Kingdom). The ureteraland urethral catheters were left in situ.8

If there were a significant residual stone, the ureteralcatheter was replaced by antegrade Double-J stent insertion.Only three patients, two with horseshoe kidneys and one withbifid pelvis, had creation of more than one tracts.

Results

Complete clearance was achieved in 39 (81%) patients afterthe single session. In nine (19%) patients, residual stones weredealt with SWL subsequently, and two (4%) patients requiredDouble-J stent insertion in antegrade manner due to signifi-cant residual stone burden, that is, more than 3 cm2. The SWLimproved the overall success rate to 96% by making anotherseven patients stone free. Twenty-five (52%) patients had this

procedure performed in supine position, and 39 (76%) calicealpunctures and subsequent tracts were created through lowerand middle calyces experiencing no impediment to the ac-cessibility to stones.

Since 2005, we are routinely carrying out tubeless PCNL innormal kidneys: that is, without nephrostomy tube at thecompletion of procedure but ureteral catheter remains in situfor the next 24 hours, and we continued to do so in 36 (75%)anomalous kidneys without any untoward incidence of ne-phrostomy site leakage or formation of urinoma.8 It is im-portant that once the percutaneous renal tract is created whilethe patient is in supine position, the time consumed to com-plete the procedure is reduced significantly as compared toPCNL performed in prone position due to the time saved byavoiding the patient’s placement in prone position. Frag-mented stone and gravel also flows out instantly due togravitational effect and the incline of the Amplatz sheath. Theoutcome of procedures is listed in Table 2.

PCNL in pelvic kidney was assisted by laparoscopy. Per-cutaneous needle puncture and subsequent tract creationwas achieved using simultaneous images through laparo-scopic camera and fluoroscopy, avoiding bowel and mesen-teric injury.

Three patients required transfusion as hemoglobin drop-ped by more than 2 g=dL postoperatively. The patient witha pelvic kidney had hospital stay extended up to 7 days as theperi nephrostomy tube leaked into the peritoneum, managedthrough the intraperitoneal drain placed at the time of sur-gery. Four patients had pyrexia �388C, and two patients hadperi nephric collection ranging from 2.5�4 cm, as measuredon the ultrasonograph. No incidence of bowel transgression,or vascular or organ injury, was recorded. The mean hospitalstay was 3 days (range, 2–7 days).

Stone analysis showed that calcium oxalate constituted83% (40) of all stones followed by a mixed composition ofphosphate, magnesium, ammonium, and uric acid in the re-maining 17% (8) stones.

Table 2. Details of Procedure: Types of Anomalous Kidneys

Malrotatedn¼ 14

Bifid pelvisn¼ 12

Horseshoen¼ 10

Hypo plasticn¼ 8

Crossed fusedectopia n¼ 3

Pelvicn¼ 1

Totaln¼ 48

Surgical positionProne 6 4 9 2 2 0 23Supine 8 8 1 6 1 1 25

Calyceal puncture(n¼ 51)

Lower 9 6 0 5 1 0 21Middle 3 6 3 3 2 1 18Upper 2 1 9 0 0 0 12

Outcome (n¼ 48)Total clearance 13 11 6 7 2 0 39Residual stone necessitating

ancillary procedures1 1 4 1 1 1 9

Post-PCNL drainageTubeless 11 10 6 7 2 0 36Nephrostomy tube 3 2 4 1 1 1 12Procedure time (minutes)

as calculated byanesthesia chart (range)

80(70–100)

75(45–105)

105(85–160)

65(35–90)

100(85–115)

180 100

PCNL¼percutaneous nephrolithotomy.

PCNL IN RENAL ANOMALIES 611

Discussion

The endoscopic treatment of large renal stones still remainsa challenge, and this becomes extreme when it is in anomalouskidneys. Sheir and colleagues9 and Tune et al10 reportedoverall success rates of 72.2% and 92% for stones in anoma-lous kidneys with SWL, but in both series the stone size was<15 mm in 74% and �10 mm in 66% patients, respectively.Stone clearance in these studies dropped down to 30–34% incase of stones size �30 mm. Therefore, in anomalous kidneysSWL is an appropriate treatment for stones up to 20 mm, butpatients with larger stones are best dealt with PCNL.11,12

PCNL in anomalous kidneys prima facie appears to be ofgreat concern due to multiple factors such as abnormal renal

and calyceal orientation, abnormal relations of the calices tothe renal pelvis and upper ureter, relative renal immobilityinterfering with maneuverability of the equipment, abnormalrenal relations with other intra abdominal organs, and ab-normal dispensation of renal vasculature.

Horseshoe kidneys (Fig 2A, B, C) are the most commonfusion anomaly with overall incidence of 0.25%,13 followed byectopia and cross-fused ectopia (Fig 3A, B, C). During renalascent at sixth week of gestation, from pelvis to the lumberregion, the renal pelvis lies on its ventral surface, which latercomes to lie medially having rotated 908 toward the midline atthe end of the ninth week of gestation. During this phase, allforms of rotational abnormalities can occur, which, as such ontheir own, may not lead to renal disease, but these varieties of

FIG. 2. Stone in horseshoe kidney. (A) Stone in control film of intravenous urogram (IVU). (B) IVU shows horseshoekidneys. (C) Post percutaneous nephrolithotomy (PCNL) results.

FIG. 3. Stone in cross-fused ectopia. (A) Control film showing radio opaque shadow. (B) IVU reveals filling defect (calculus)in this anomaly. (C) Post PCNL results.

612 RANA AND BHOJWANI

rotational anomalies are revealed incidentally when anindividual is subjected to IVU.14

Static investigations like ultrasound, IVU, or CT are man-datory in regard to the choice of position of the patient onoperative table, whether supine or prone, choice of calix forpuncture, and tract creation in normal kidneys. The final de-cision in this respect in patients with anomalous kidneys isbest made during dynamic fluoroscopic views while per-forming retrograde urography. Amenability of the surgeon toalter the conventional PCNL technique, in anomalous kid-neys, as situation demands can convert this demanding pro-cedure into a straightforward one achieving desired results.

There has been a degree of apprehension about the pres-ence of retrorenal colon associated with fusion anomalies thatis due to the defect in the normal development of lateral conalfascia resulting in deficiency of mechanical support to thecolon. Therefore, horseshoe kidneys are more often associatedwith posterolateral or retrorenal colon.15 None of our patientssuffered from any bowel injury, but this concern led Al Otaibiand Hosking5 to recommend CT scan in every patient withstones in horseshoe kidney, and we were inclined to followsuit. Hence, all patients with horseshoe kidneys and otherfusion anomalies requiring PCNL must undergo CT scan atour center. Shokeir et al16 reported only single incidence ofbowel injury in 34 patients undergoing PCNL in horseshoekidneys that was managed conservatively. In our study nosuch complication was recorded.

In all recent studies there has been exaggerated emphasisand preference for the upper calyceal puncture and tractcreation at the rate of 100%, 63%, and 62%.16–18 It is evidentthat even though IVU in anomalous kidneys does not neces-sarily demonstrate exact demography of the calices, decisionfor the choice of calix for tract creation is eventually finalizedper operatively during dynamic fluoroscopic visuals of ret-rograde urography. Although upper and lower caliceal punc-tures provide flexibility of accessing other calices as well, wehad no preference for a particular calix but chose the one that

was well dilated and easily accessible, either in supine orprone position, leading on to the stone. In our study, 39 (76%)tracts were created through middle and lower calyces, indi-cating that the choice of caliceal puncture needs to be indi-vidualized according to the anatomy of each renal unit andurologist’s preference.

Although Raj et al18 claimed use of flexible nephroscope in80% patients to access stones in various calices adequatelyin horseshoe kidneys, we did not have flexible nephroscope inour armamentarium; therefore, it is difficult to draw a com-parison.

It is significant to note that Janetschek and Kunzel19 foundthat PCNL does not impose a higher risk of bleeding inhorseshoe kidneys compared to normal kidneys as all bloodvessels, except some supplying to the isthmus, enter or leavethe kidney from its ventromedial aspect. In rotational anom-alies, therefore, the identification of the position of the pel-viureteral junction is the key in determining the proposedcaliceal puncture, which must be away from the pelviureteraljunction as most vessels lie close to it. Our experience revealsthat no additional risk of hemorrhage is associated withPCNL in anomalous kidneys in contrast to normal kidneys.Stone-free status was achieved in 81% (n¼ 39) patients after asingle session of PCNL, which further improved to 96% whencombined with SWL as an ancillary treatment for residualstones. Two patients with horseshoe kidneys required morethan one tracts as initial upper caliceal access resulted in un-usually long tracts exposing the limitations of renal mobilityand maneuverability of the Amplatz sheath and nephroscope,enforcing creation of additional tract.

The renal hypoplasia and kidneys with bifid pelvis, al-though relative anomalies, are usually associated with degreeof malrotation, but carrying out PCNL in these kidneys isrelatively straightforward. The most stringent requirements,however, in these anomalies are to create perfect calicealpunctures and to maintain the accessibility of the PCNL tractwith a guide wire throughout the procedure. The primary

FIG. 4. Stone in pelvic kidney. (A) Stone in pelvic kidney. (B) IVU shows functional status of the kidney. (C) Post PCNLresults.

PCNL IN RENAL ANOMALIES 613

stone clearance in anomalous kidneys, excluding horseshoekidneys, has been 89% (34 patients), which is comparable withPCNL in normal kidneys. The most important factor, how-ever, remains the judgment of the surgeon in making peroperative decisions with regard to position of the patient andaccess of a particular calix or creation of additional tracts.

Laparoscopy-assisted transperitoneal PCNL was per-formed in a patient with pelvic kidney (Fig 4A, B, C).Simultaneous laparoscopy and fluoroscopy facilitated thespinal needle to puncture the desired calix without interpo-sition of bowel or mesentery. This procedure was relativelytime consuming (180 minutes) with two surgical teamsworking concurrently. Insertion of peritoneal drain in addi-tion to nephrostomy tube served best to prevent accumulationof leakage into the peritoneal cavity.

The overall incidence of complications was low. Three pa-tients (6%) required transfusion as their hemoglobin droppedby 2 g=dL. Significant blood loss may occur during tract cre-ation and PCNL in normal kidneys with transfusion rateranging from 3–12%.20 A patient with pelvic kidney had ex-tended hospital stay as she had a perinephrostomy tube leakinto the peritoneal cavity. Three patients had postoperativepyrexia �388C, and two patients had perinephric collectionmanaged conservatively. None of our patients had bowel,vascular, or splanchnic injury. The mean hospital stay was 3days (range, 2–7 days).

Conclusion

Application of PCNL is a comprehensive procedure insupine or prone position for large and complex renal stonesin adverse renal diversity such as fusion, malrotation, mal-position, hypoplasia, and pelvicaliceal aberrations, and ityields safe and comparable results demanding firm determi-nation on behalf of the urologist to confront these challengesupfront.

Disclosure Statement

No competing financial interests exist.

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Address reprint requests to:Abdul Majid Rana, MBBS, FRCS (Ed)

Department of UrologyThe Kidney Centre Post Graduate Training Institute

Dow University of Health Sciences197=9, Rafiqui Shaheed Road

75530 KarachiPakistan

E-mail: rana_abdulmajid@hotmail.com

Abbreviations Used

CT¼ computed tomographyIVU¼ intravenous urogram or intravenous urographyKUB¼ kidney, ureter, and bladder radiograph

PCNL¼percutaneous nephrolithotomySWL¼ extracorporeal shockwave lithotripsy

614 RANA AND BHOJWANI

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