Plasma renin activity in children after surgical relief of hydronephrosis.

Blood pressure and supine plasma renin were measured in fourteen children aged seven to eighteen years whose hydronephrosis had been relieved surgically two to eleven years previously. Values did not differ significantly from age matched controls. It has been suggested that renal ischemia may persist after relief of hydronephrosis but our results show that hyperreninemia rarely occurs within two to eleven years of effective surgery. Further studies of blood pressure and renin after this period of time remain to be done.