Follow-up of prenatally diagnosed unilateral hydronephrosis.

Based on previous experience with prenatally diagnosed unilateral hydronephrosis, we found that the primary indications for surgical intervention should be symptoms or functional impairment of the hydronephrotic kidney. Nonoperative management of neonates without symptoms and with normal function of the affected kidney was proposed. However, the strategy of treatment after prenatally diagnosed hydronephrosis is still controversial. We studied 28 consecutive children with suspected unilateral pelviureteral junction obstruction and a normal contralateral kidney. The overall follow-up period varied between 2.5 months and 6 years (median 2 years). Eleven children had normal function of the hydronephrotic kidney and were managed nonoperatively throughout the follow-up period. None of these demonstrated any symptoms and the renal function remained normal. A further 4 children with normal function of the affected kidney were managed nonoperatively, but later had a pyeloplasty performed because of either symptoms or deterioration of renal function. Eleven children had a pyeloplasty performed after the first renography showed that the hydronephrotic kidney provided less than 40% of total renal function. The age at pyeloplasty was 3 weeks- 7 months (median 6 weeks). In all cases but 1 the function of the affected kidney improved. Two patients with impaired hydronephrotic renal function were not operated upon. Our results indicate no need to change the strategy of treatment.