Renovascular hypertension from segmental renal artery stenosis: importance of segmental renal vein renin sampling.

We report a case of severe hypertension in a girl with no evidence of parenchymal renal disease. Arteriography revealed segmental stenosis and a saccular aneurysm affecting a branch of the left renal artery. Segmental renal vein renin sampling demonstrated a markedly increased rate of renin secretion from the ischemic portion of the left kidney. Partial nephrectomy resulted in normalization of the blood pressure. The resected kidney showed striking hyperplasia of the juxtaglomerular apparatus and medial fibromuscular dysplasia as the etiology of the arterial stenosis. This case emphasizes the value of segmental renin vein sampling in the evaluation of pediatric hypertension and illustrates the high cure rate obtained by surgical correction.