POSTNATAL MANAGEMENT OF ANTENATALLY DETECTED, BILATERAL HYDRONEPHROSIS

26 children, with antenatally detected, isolated, bilateral hydronephr osis (thus consistent with pelvi-ureteric junction obstruction), were investigated for up to 7 years. The aim was to avoid operation. 34 kid neys were never operated on. Despite initially often severe hydronephr osis and poor isotope wash-out on the renogram, half of the kidneys im proved or even normalized during follow-up. The final glomerular filtr ation rate (GFR) was always normal or almost normal. 18 kidneys came t o surgery, because of poor filtration, symptoms or social reasons. At the end of the follow-up, GFR was normal in all but 2 kidneys. In a su bgroup of the kidneys, with initially severe reduction in filtration, half were operated on and half were not; at the end, the GFR was norma l in all of the non-operated kidneys (and in all but 1 of the operated kidneys). Total GFR was at the end normal or almost normal also in th e children with persistingly filtration-reduced kidneys (always unilat erally), because of compensation by the contralateral, although hydron ephrotic kidney. Thus, in this study the renographic parameters were n ot very helpful in predicting the prognosis. There was no consistent d ifference between operative and nonoperative treatments on final filtr ation. Also hydronephrotic kidneys possessed a substantial capacity fo r contralateral compensation. It is concluded that the initial approac h to bilateral, antenatally diagnosed hydronephrosis may safely be non -operative. This allows time for the clear expression of sustained imp airment of renal filtration requiring surgical intervention.