Whitaker test after pyeloplasty: establishment of normal ureteral perfusion pressures.

Twenty-seven patients underwent percutaneous ureteral perfusion after successful surgical repair of ureteropelvic junction obstruction in order to determine the perfusion pressures in ureters without obstruction. In each patient, the postoperative ureteropelvic junction appeared widely patent and the rest of the ureter appeared entirely normal. Ureteral perfusion was performed via percutaneous puncture of the collecting system; the pressure in the pelvis was measured through this needle and bladder pressure was monitored through a urethral catheter. "Absolute" (renal pelvic) and "differential" (renal pelvic minus bladder) pressures were measured at 10, 15, and 20 ml/min perfusion rates. Absolute and differential pressures rose as the perfusion rates increased; absolute pressure rose but differential pressure fell as the bladder was filled. The upper limit of normal differential pressure encountered with the bladder empty was 13 cm of water during perfusion at 10 ml/min.