Management of ureteropelvic junction obstruction associated with lower polar vessels.

Four cases of hydronephrosis due to ureteropelvic junction (UPJ) obstruction by lower polar vessels are presented. Regular propagation of peristaltic waves across a patent UPJ and rapid emptying of the pelvis were the basic conditions before accepting the lower polar vessels as the primary cause of the hydronephrosis. Transposition or division of the lower polar vessels, accompanied sometimes by a limited lower polar nephrectomy dependent on the resultant ischemia, without any pyeloplasty was the selected procedure in each of the cases. No hypertension and no immediate or delayed postoperative complications occurred in any of our patients. Relief of symptoms, a remarkably improved postoperative pyelogram, and a sterile urine were achieved in all our cases. Detection of every case in which the lower polar vessels play a primary role in the establishment of UPJ obstruction is urged since transposition or division of these vessels in such cases is a superior procedure to pyeloplasty.