Renal dynamics after pyeloplasty.

Dismembered pyeloplasty was done on 12 renal units for ureteropelvic junction obstruction. Postoperatively, response of repaired kidney to standard diuretic dose of furosemide (0.3 mg/kg) was evaluated. Also renal pelvic pressures at rest and during diuresis were measured. All renal units responded to the diuretic by increasing their urine output an average of three times over baseline value. Renal pelvic pressure registration revealed no significant change after diuresis over baseline values. Diuretic technetium-99 DTPA renal scans were obtained two to six months postoperatively and compared with preoperative scans; the best results were obtained in renal units whose intrapelvic pressures did not exceed 10 cm of water in the immediate postoperative period.