The many techniques of continent bladder substitution after radical cystectomy entail the risk of a wide spectrum of complications.1 To our knowledge we report the first case of orthotopic bladder substitution via modified Studer technique,2, 3 in which postoperative thrombosis of the pouch mesentery led to pouch shrinkage with secondary deterioration of renal function due to high intraluminal pressures and reflux. CASE REPORT A 60-year-old man presented with muscle invasive bladder cancer and a nonfunctioning left hydronephrotic kidney. Cystoprostatectomy and left nephroureterectomy were performed. An orthotopic small bowel reservoir was constructed from a W-shaped 45 cm. ileal segment, and the right ureter was anastomosed to an afferent 10 cm. ileal loop in a modification of the Studer technique.2, 3 Intraoperative venous bleeding from the pouch mesentery required a Z-shaped suture. Pouch vascularization appeared to be compromised. However, no further bleeding occurred after ligature removal, and reservoir color and perfusion returned. Urography on postoperative day 10 showed a normal upper urinary tract with slight pyelectasis on the right. Pouchography on postoperative day 14 demonstrated normal reservoir capacity and anastomosis with reflux into the right kidney. At hospital discharge the patient reported complete day and night continence. Two months after cystectomy the patient returned to the hospital for renal insufficiency and metabolic alterations (creatinine was 4 ng./ml., normal 0.6 to 1.3). Cystography revealed a low capacity (70 ml.) pouch and reflux into the right solitary kidney (fig. 1, A). We initiated transurethral diversion by catheterization, and 3 months later all laboratory values had stabilized (creatinine was 1.9 ng./ml.). Endoscopy revealed a rigid pouch with atypical, scarred and pale enteric mucosa. Suspecting pouch shrinkage from vascular insufficiency, we recommended conversion to incontinent urinary diversion with an ileal conduit but the patient insisted on continent diversion. The risks of augmentation of the shrunken pouch were discussed with him in detail. Intraoperatively, much of the pouch was rigid, scarred and severely adherent to the surrounding tissue and required resection (fig. 2, A). However, the margins of the distal and caudal segments appeared to be well perfused. A funnel of the afferent loop and the caudal aspect of the pouch with intact mesenteric vascularization could remain in situ. Augmentation was performed with a 20 cm. segment of ileum, which was detubularized, formed into a U-shape and sutured to the caudal base of the original pouch and afferent loop (fig. 2). After a 17-day hospitalization, the patient was discharged home. Histological evaluation of the resected reservoir revealed changes consistent with a circulatory deficit caused by mesenteric venous thrombosis, although complete hemorrhagic infarction was not seen.