Decompensated ureteropelvic junction obstruction in renal allograft.

We report a case of complete obstruction at the ureteropelvic junction in a renal allograft 6 months after related kidney transplantation. Surgical treatment consisted of a Foley nondismembered Y-V pyeloplasty. Although the donor harbored undetected bilateral, mild, ureteropelvic junction stenosis, as established by review of the excretory urogram that was performed before nephrectomy, the remaining kidney functioned well, as confirmed by renal function and morphological appearance on a repeat excretory urogram. The possible mechanisms of ureteropelvic junction decompensation, the most crucial of which appears to be autonomic denervation of the allograft, are discussed.