Pararenal pseudocyst (urinoma) as complication of percutaneous nephrostomy

PARARENAL

PSEUDOCYST

COMPLICATION LUIZ A. PORTELA,

(URINOMA)

OF PERCUTANEOUS

AS NEPHROSTOMY

M.D.

SURESH

K. PATEL,

M.D.

DANIEL

H. CALLAHAN,

M.D.

From the Departments of Diagnostic Radiology and Urology, Rush-Presbyterian-St. Luke’s Medical Center, Chicago, Illinois

ABSTRACT - Percutaneous nephrostomy is a well-recognized procedure utilized by the radiologist both as a temporary drainage method for urinary tract obstruction and as the elective therapeutic not previously menmodality in selected pathologies of the urinary tract. We report a complication tioned in the literature, urinoma formation.

For the radiologist percutaneous nephrostomy is a well-recognized procedure, with a total of almost 600 reported in the literature.3 Fifteen percutaneous nephrostomies have been performed in our department since 1974. The indications and technique are well established and the complications described include: pyelonephritis induced or exacerbated by obstruction of

the catheter, transient urine peritonitis, pyelocalyceal blood clot retention due to serious hemorrhage, transient hematuria, temporary catheter dislodgment or obstruction, small retroperitoneal hemorrhage, and retroperitoneal urine extravasation.3 We report urinoma formation as a delayed complication of percutaneous nephrostomy.

FIGURE 1. (A) Excretory urogram done on first admission demonstrating large filling defects and irregularity of bladder. Cystoscopy permitted visualization of large tumor and blood clots in bladder. There is dilatation of entire right ureter and right hydronephrosis. Left kidney is nonfunctioning; it was noted to be hydronephrotic during total body opacification phase in earlier radiograph. (B) Radiograph obtained after percutaneous nephrostomy. Tefion catheter tip is close to kink of dilated ureter, but no importance was attached to this at that time.

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Case Report A seventy-year-old white man was admitted to this Center on November 17, 1977, complaining of increased frequency of urination, urgency, and dysuria for three months. He described an episode of hematuria lasting for one week, occurring six weeks prior to admission, with loss of appetite and a 16-pound weight loss. Past medical history was noncontributory. Physical examination revealed an enlarged prostate, with no other significant finding. Laboratory workup demonstrated elevated serum potassium, chloride, carbon dioxide, blood urea nitrogen, and creatinine. Urinalysis showed microscopic hematuria and marked pyuria. Excretory urogram on November 18, 1977, showed a nonfunctioning hydronephrotic left kidney and hydronephrosis of the right kidney due to obstruction of the ureter at the ureterovesical junction by a large bladder tumor (Fig. 1A). Cystoscopy, also done on November 18, confirmed a large necrotic tumor in the bladder. Biopsy was positive for papillary transitional cell carcinoma. A right percutaneous nephrostomy was done on the evening of the same day in an attempt to relieve the obstruction and improve the patient’s clinical status. Urinary output through the nephrostomy tube was low the following day but became appropriate (above 1,000 cc./24 hours) in the next two days. Laparotomy was done on November 22, 1977; there was no extension of the tumor outside the bladder or palpable pelvic lymph nodes. A large amount of urine was found in the right retroperitoneal space during dissection of the ureter, but the renal fascia was not opened. An ileal conduit was fashioned and anastomosed to the skin and ureters. The bladder was left in place, to be removed after a short course of radiotherapy and improvement of the patient’s clinical status. Immediately before discharge, on December 6, 1977, a liver-spleen scan showed a large extrinsic pressure defect in the posterior portion of the right lobe of the liver. SMA-6 was normal except for a creatinine of 2.7 mg./lOO ml. The patient was readmitted on January 8, 1978, for cystectomy and radiotherapy. An excretory urogram was done for re-evaluation of the renal status; again the left kidney was nonfunctioning and the right kidney hydronephrotic, but with no delay in excretion (Fig. 1B). The right kidney was seen to be displaced anterolaterally by a cystic mass with thick walls.

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FIGURE 2. Computed tomography scan of abdomen on second admission shows anterolateral displacement of right kidney. There is rounded collection ofjuid surrounded by thick capsule medial and posterior to kidney, representing urinoma.

Computed tomography body scan confirmed the finding of a collection of fluid in the renal fascia, surrounded by a thick capsule (Fig. 2). Puncture of the urinoma was not attempted for fear of contamination of this single-functioning kidney. Comment Urinoma formation as a complication of percutaneous nephrostomy has not, to our knowlbeen previously reported in the litedge, erature. Retroperitoneal urinary leaks have been described,a but apparently they were subsequently reabsorbed and produced no clinical problems. The classic elements for formation of urinary pseudocysts were present in our case: functioning renal tissue, ureteral obstruction, and interruption in the continuity of the collecting system, produced by the percutaneous puncture. ‘3’ Our technique involves the use of a Teflon catheter, which probably became partially obstructed against a kink of the tortuous ureter. The urinary leak into the renal fascia was already organized in a urinoma at the time of discharge, as evidenced by the extrinsic defect on the liver scan. Postprocedural follow-up of patients submitted to percutaneous nephrostomy should include this fact in the differential diagnosis of reduced urinary output. This complication can be prevented by repositioning of the nephrostomy tube to establish an adequate drainage. Chicago, Illinois 60612 (DR. PATEL) References 1. Friedenberg R, and Scully R: Case records of the Massachusetts General Hosp. 52-1977, N. Engl. J. Med. 297: 1454 (1977). 2. Meyers M: Uriniferous perirenal pseudocyst: new observations, Radiology 117: 539 (1975). 3. Stables D, Ginsberg N, and Johnson M: Percutaneous nephrostomy, A.J.R. 130: 75 (1978).

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