Late ureteropelvic necrosis after transplantation.

Total ureteropelvic necrosis of the transplanted kidney occurred more than one month after transplantation in 5 of 575 consecutive renal transplants performed at the University of Minnesota Hospital since 1963. Necrosis became evident long after normal renal function had been established. Histologic signs of rejection were minimal, but perinephric or periureteral hematomas were found in 3 of 5 patients: post-transplant acute tubular necorsis requiring hemodialysis occurred in all. The pathogenesis of this complication probably involves (1) a primary deficit of blood supply from the renal vessels to the pelvis and ureter, (2) a failure to develop a new ureteral blood supply because of surrounding hematoma, (3) early swelling of the ischemic ureter resulting in oliguria interpreted as acute tubular necrosis, (4) resolution of edema resulting in diuresis, and (5) late patchy ureteral necrosis and fistula formation due to ureteral ischemia.