Nonsurgical management of renovascular hypertension in the neonate.

Over an 18-month period nine infants in a neonatal intensive care unit developed hypertension (blood pressure, 115/88 to 280/140 mm Hg) at 2 to 45 days of age. Eight of the nine infants had indwelling umbilical artery catheters prior to onset of hypertension; six of the nine infants had evidence of a patent ductus arteriosus. Peripheral plasma renin activity was greater than 300 ng/ml/3 hr in six of eight infants. Angiograms were abnormal in six of seven infants and computerized renal scans were abnormal in all nine infants. One infant had congenital renal artery stenosis. Eight of nine infants had evidence of unilateral or bilateral renal artery thrombi which were felt to have emanated from an umbilical artery catheter or a ductus arteriosus. Hypertension in all infants was successfully controlled medically (follow-up of 3 to 27 months; mean, 14.4 months). Blood pressures remained normal when medication was discontinued. In our experience, neonatal renovascular hypertension is no longer uncommon, responds to aggressive medical management, and rarely requires early nephrectomy. Neonatal renovascular hypertension was usually associated with umbilical artery catheters positioned above the level of the renal arteries.