Polar Nephrectomy in a Transplanted Kidney: A Case Report

Polar Nephrectomy in a Transplanted Kidney: A Case Report R.A.S. Cacciola, V. Etazadi, M.A. Ilham, and A. Asderakis ABSTRACT After renal transplantation, infarction of the lower pole may be observed. We report an unusual case of lower pole infarction and perforation of the lower calyx due to thrombosis of a lower polar artery. This was managed successfully with partial nephrectomy (nephron-sparing surgery).

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MONG a wide variety of surgical complications that may occur after renal transplantation, infarction of the lower pole alone can be accompanied by ureteric necrosis and lead to urine leak. In contrast to total graft thrombosis and focal perfusion defects, infarction of the lower pole has been the subject of only a few previous reports.1– 4 Most commonly, the infarcted or under-perfused area heals without abscess formation. During the past few years, some studies have shown successful treatment of polar necrosis with abscess formation by partial nephrectomy instead of the traditional approach of transplant nephrectomy.4 We have reported herein an unusual case of lower pole infarction, perforation of the lower calyx, and partial necrosis of the renal pelvis due to a lower polar artery thrombosis, which was managed using partial nephrectomy with primary closure of the collecting system. CASE REPORT Background A 52-year-old man with a 3-year history of end-stage renal failure secondary to antiglomerular basement membrane disease (Goodpasture’s syndrome) underwent cadaveric renal transplantation. The donor was a 54-year-old, non– heart-beating men (Maastricht type 3). The graft had 2 renal arteries (RA) and a single vein. The renal arteries on a Carrel patch were anastomosed to the right external iliac artery with 6/0 prolene running suture. Total cold ischemia time was 17 hours and 44 minutes. The neouretero-cystostomy was fashioned using 4/0 PDS with a double J stent. There were no intraoperative complications. The patient received immunosuppression with tacrolimus, mycophenolate mofetil, and prednisolone. He displayed good postoperative recovery after an initial, expected period of delayed graft function (DGF). He was discharged after 10 days with a serum creatinine level of 237 ␮mol/L and still improving.

Presentation The patient’s renal function improved daily, although a difficultto-treat high blood pressure (BP) was noticed from the early stages. On day 56 posttransplantation the patient appeared in the trans-

plantation clinic; he was afebrile but with slightly worse renal function and with a BP of 165/95. An ultrasound scan was planned for the following day. His general condition rapidly deteriorated and he presented as an emergency in the Accident and Emergency Department with a hypertensive crisis, consisting of a high BP (210/110), severe headache, nausea, and vomiting. He underwent an emergency duplex examination that revealed stenosis of 1 of the transplanted RA, whereas the second 1 was not visualized, he displayed also a large collection of fluid (Fig 1). A biopsy specimen obtained at that time did not show evidence of acute rejection. His creatinine level increased to 595 ␮mmol/L. In view of the results of duplex scan and lack of evidence for other causes for the deterioration in renal function, he underwent an emergency arteriogram of the transplanted kidney that revealed a long stenotic segment of the transplanted RA with possible compression “ab extrinseco,” with the second lower polar artery not visualised (Fig 2). A nuclear renogram confirmed good perfusion to most of the kidney, with only a small amount of filtrate in the bladder but also a small urinary leak. It was decided to explore the transplanted kidney with the provisional diagnosis of RA stenosis secondary to a perinephric collection (urinoma).

Operation At exploration there was a large amount of fluid that proved to be urine but did not look grossly infected. The kidney that was fully exposed after a difficult dissection showed an area of ischemia and necrosis in the lower pole extending toward the hilum that measured 4 ⫻ 4 cm with the rest of the graft well perfused. Both arteries anastomosed on a Carrell patch seemed small. The lower artery supplying the lower pole was thrombosed. The ureter looked dusky although not frankly necrotic with a stent still in situ. To identify the site of the leak, the bladder was filled with 0.9% NaCl solution. No leak was identified at the site of the neoureterocystostomy. The fluid stayed in the ureter with increased pressure in the renal system, watery urine was seen from a small hole within From the Renal Transplant Unit, Guy’s Hospital, London, United Kingdom. Address reprint requests to Roberto Antonio Simone Cacciola, MD, MS, FRCSI, Guy’s Hospital, St. Thomas Street, London SE1, 1NZ, United Kingdom.

0041-1345/07/$–see front matter doi:10.1016/j.transproceed.2007.03.022

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Fig 1. Ultrasound appearance of transplanted kidney showing large fluid collection. the necrotic area of the kidney away from the hilum. It was obvious that a renal calyx was open. The opening looked like a circle in the necrotic lower pole of the transplanted kidney (Fig 3). A decision was made to excise the necrotic part of the kidney. The main RA was of small calibre, however, the part of the kidney supplied by this artery was well perfused, and there was no evidence of stenosis along its course. Thus, the previous stenosis was attributed to external compression by the urinoma. Following the excision of the necrotic part, the wall of the lower calyx was repaired with 4/0 PDS and covered by approximating the edges of the kidney with the aid of PTFE felt using 3-0 Prolene. Subsequently the transplanted ureter was traced up to the renal pelvis, mobilized, and removed. The peritoneum was opened and the native right ureter of the patient was identified and dissected proximally and distally. It was divided proximally and ligated. The distal end was anastomosed directly to the distal end of the pelvis of the transplanted kidney over a 22 ⫻ 6 double J stent, using 4/0 PDS continuous suture. A drain was left close to the resected area. There was immediate production of urine. Renal function recovered dramatically during the following day (creatinine level of 164 ␮mol/L). No major complications were observed, although a small, expected leak of urine that appeared through the drain gradually reduced and was successfully treated conservatively. At discharge, 17 days postoperatively graft function was stable with a serum creatinine level of 159 ␮mol/L and urea of 10.8 mmol/L. The patient had a normal cystoscopy for removal of the ureteric stent after 82 days. At 6 months follow-up the graft was still functioning normally with a creatinine level of 150 ␮mol/L and well-controlled BP.

DISCUSSION

Infarction of the lower pole following renal transplantation is not a rare complication.4 It may occur either because an aberrant artery to the lower pole has not been revascularized or because of anastomotic complications.5 In such cases, necrosis of the ureter may occur. It may also be

associated with a thrombotic or embolic occlusion of an intrarenal segmental artery, which may leave the blood supply to the ureter intact.4 It typically occurs in the early postoperative period. Unless it causes ureteric necrosis, prompt diagnosis is sometimes difficult.2 The onset of infarction may be asymptomatic or with nonspecific symptoms, such as intractable hypertension, but it is usually associated with impaired allograft function. Sometimes this impairment is negligible due to the small area of the kidney supplied by a small polar artery. An anatomical lesion, defect in surgical technique, graft tubular damage, and prolonged ischemic time have been identified as risk factors for partial graft thrombosis.6 The accurate examination of the collecting system has proven to be extremely important, because repair of the collecting system was necessary in this case due to exposure of an open calyx by the initial necrotic process. The use of the native ureter prevented potential complications from the transplanted ureter, because its blood supply was already seriously compromised. Drainage of the perinephric area proved to also be important, because postoperative urinary leak was predictable in such repairs. If left to pool locally, it may prevent healing and promote infection. In the postoperative period, small leaks can be treated conservatively, especially if the drainage is efficient. The graft function keeps improving and the urinary outflow is free. In conclusion, polar necrosis of a transplanted kidney even when it causes urine leak from the necrotic area of the kidney does not always dictate transplant nephrectomy. Recognition of calyceal damage with repair of the calyx is essential to avoid further urine leakage. This unusual case, where lower polar necrosis led to calyx perforation, urine leak, and compression of the main RA, shows that nephron- sparing surgery

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Fig 2. Arteriogram of transplanted kidney showing a long stenotic segment of RA.

of an otherwise functioning graft may be performed successfully even in the presence of intense inflammation or even a neoplastic process as recently shown.7 REFERENCES 1. Tilney NL, Kirkmann RL: Surgical Aspects of Kidney Transplantation. New York: Garovoy- Guttmann; 1986, p 93 2. Kanchanabat B, Siddins M, Coates T, et al: Segmental infarction with graft dysfunction: an emerging syndrome in renal transplantation. Nephrol Dial Transplant 17:123, 2002 3. Budihna NV, Milcinski M, Kajtna-Koselj M, et al: Relevance of Tc 99m DMSA scintigraphy in renal transplant parenchymal imaging. Clin Nucl Med 19:782, 1994

4. Nehoda H, Hochleitner BW, Chemelli A, et al: Successful resection of an infracted lower pole in transplanted kidney. Nephrol Dial Transplant 13:1021, 1998 5. Gutierrez-Calzada JL, Ramos-Titos J, Gonzalez-Bonilla JA, et al: Calyceal fistula following renal transplantation. Management with partial nephrectomy and ureteral replacement. J Urol 53:612, 1995 6. Singh A, Stablein D, Tejani A: Risk factors for vascular thrombosis in paediatric renal transplantation: a special report of the North American Paediatric Renal Transplant Cooperative Study. Transplantation 63:1263, 1997 7. Moudouni SM, Tligui M, Doublet JD, et al: Nephron-sparing surgery for de novo renal cell carcinoma in allograft kidneys. Transplantation 6:865, 2005

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Fig 3. Intraoperative appearance of transplanted kidney showing a necrotic lower pole and circular opening of the calyx.