Fibrosis of a renal transplant ureter.

Ureteral obstruction following renal transplantation, although not a common occurrence, is a serious complication because of the single functioning kidney. Obstruction may be caused by ureterovesical stenosis, retroperitoneal fibrosis or adhesions, clot formation, pelvic lymphoceles or kinking of the ureter. A case is presented in which there was progressive partial ureteral obstruction caused by fibrosis and stricture of the transplant ureter, which were probably owing to rejection episodes.