Figure 18a. Fistulas of urinary diversion. (a) Neobladder-vaginal fistula due to creation of an ileal neobladder in a patient who underwent cystectomy for bladder cancer. Radiograph obtained after introduction of a catheter (arrow) into the vagina shows injected contrast material delineating the orthotopic bladder (B). In fact, the catheter tip appears to have entered the neobladder through the fistula, resulting in a transvaginal cystogram. (b) Ileal loop-perineal fistula in a patient who underwent total pelvic exenteration and urinary diversion to an ileal loop. Nephrostogram shows a fistula (arrowheads) extending from the ileal loop (L) into the perineum. Management of such fistulas involves percutaneous nephrostomy to divert urine from the fistula and may even require temporary or permanent ureteral occlusion.