Does delaying pyeloplasty affect renal function in children with a prenatal diagnosis of pelvi-ureteric junction obstruction?



Objective  To evaluate retrospectively children with an antenatal diagnosis of pelvi-ureteric junction (PUJ) obstruction who required pyeloplasty for deteriorating renal function during the follow-up, specifically assessing the recovery of function after surgery.

Patients and methods  Between 1988 and 2000, 44 consecutive patients with a prenatal diagnosis of PUJ obstruction who were initially treated by observation underwent pyeloplasty because their renal function deteriorated during the follow-up. Patients with bilateral disease, a single kidney or vesico-ureteric reflux were excluded from the study. The mean ( sd ) age of the patients was 13.3 (4.5) months and their mean (range) initial renal function 39.7 (30.4–45)%. In all patients the diagnostic criteria and indications for surgery were identical. The main indication for surgery was deteriorating renal function of >5%, confirmed by renal scintigraphy. Of 44 patients, 35 (77%) had severe dilatation of the renal pelvis by >3 cm. The mean ( sd ) deterioration in renal function during the follow-up, just before surgery, was 8.2 (2.4)%, and the mean time between the last acceptable renogram and the study showing deterioration was 8.3 (1.3) months; the mean follow-up was 5.1 (1.6) years. The results were assessed statistically using the unpaired nonparametric Mann–Whitney U -test.

Results  An improvement in hydronephrosis was confirmed in all patients, with renal function returning to the initial levels in 36 of 44 (81%) patients 6–12 months after surgery, although in two patients renal function did not improve after surgery. There was no significant difference between the preoperative characteristics and the degree of hydronephrosis, renal function or patient age with the level of renal functional improvement after surgery.

Conclusion  In patients with an antenatal diagnosis of PUJ obstruction, expectant management is recommended and spares the children unnecessary surgery. Even if renal function deteriorates, delayed pyeloplasty recovers the initial functional level.