Renal-Transplant Ureteral Obstruction Simulating Retroperitoneal Fibrosis

Two kidney transplant recipients developed impairment of renal function that was subsequently found to be due to retroperitoneal fibrosis. In one patient, the precipitating event was trauma with retroperitoneal hemorrhage, whereas in the other, it was talc retroperitonitis. Since the host ureter was uninvolved by the fibrotic process, return to normal renal function was achieved in both cases by donor-host pyeloureterostomy. Retroperitoneal fibrosis should be considered in any kidney transplant patient with failing renal function; the fibrosis surrounding the transplanted ureter can lead to obstructive uropathy in spite of a normal ureteral caliber, and thus may be confused with other causes of failing kidney function.