The functional outcome of Anderson-Hynes pyeloplasty for hydronephrosis

35 patients, age 3-69 years, mean 27, with pyeloureteric junction obstruction and hydronephrosis on I.V.P. were operated by Anderson-Hynes pyeloplasty. Prior to operation all patients were further investigated by renal scintigraphy. The postoperative follow-up consisted of a second I.V.P. after 12 months and repeated scintigraphies once or twice yearly. Mean follow-up time was 28 months. Thirty-three % of the patients with a decreased 2 min uptake fraction preoperatively had a significant increase in renal function after surgery. This increase was seen within the first 12 months. The rate of increase was greatest in patients below 30 years. Older patients only showed stabilized function. None of the patients had significant decrease in renal function. There was no correlation between the change in renal function and change in the I.V.P. It is concluded that an active surgical attitude in hydronephrosis is justified. Furthermore, follow-up after reconstruction could be limited to a renography 6 and 12 months postoperatively in otherwise asymptomatic cases with stable or improved uptake fraction.