The captopril test in children with renovascular and renal hypertension.

We used the captopril test (CT) in 32 children, 8 with renovascular hypertension (RVH), 17 with renal hypertension (RH) and 7 with normal blood pressure, in order to study the renin-angiotensin system activation (RASA). All children affected by RVH presented a positive CT: a post-captopril plasma renin activity (PRA) of 12 ng ml-1 h-1 or more, an absolute PRA increase of 10 ng ml-1 h-1 or more and a 150% increase or more, or 400% or more if the baseline PRA was less than 3 ng ml-1 h-1. The CT may be useful for demonstrating the RASA in RVH.

Percutaneous transluminal renal angioplasty in neurofibromatosis.

A 9-year-old boy with hypertension was found to have neurofibromatosis associated with stenosis of the right renal artery. Percutaneous transluminal angioplasty (PTA) was performed. Immediately post angioplasty angiography showed that the stenosis persisted, but over the next few days his blood pressure rapidly decreased and remained well controlled even when treatment was discontinued. The captopril stimulation test, performed after PTA, confirmed the return of plasma renin activity to normal values. A digital subtraction aortogram, performed 2.5 years after PTA, was unchanged. His blood pressure remained persistently normal, without anti-hypertensive agents. Based on these results, PTA is suggested as the first step in correcting renal artery stenosis due to neurofibromatosis. A complete anatomical resolution of the stenosis is probably not required since slight improvements in the renal artery lumen may be accompanied by important functional improvement.