Fibromuscular Hyperplasia of the Renal Artery: An Enigma

FIBROMUSCULAR hyperplasia of the renal artery has emerged as a lesion of major importance in causation of renal vascular hypertension.¹⁻⁴It has received attention, primarily in the surgical literature,¹,³,⁴as a potentially curable lesion, occurring predominantly in young women.³ Pathologically, fibromuscular hyperplasia is unassociated with primary atheromatous disease and has been described as characteristically excluding the proximal third of the renal artery.²The lesion is marked by proliferation of fibrous tissue and smooth muscle fibers, frequently associated with degeneration of elastic fibers, the end result being narrowing of the renal arterial lumen. Although it may present as a single area of stenosis, it frequently involves a considerable length of renal artery with alternate areas of atrophy and proliferation which give the artery a "beaded" appearance radiographically. Poststenotic dilatation may be marked. Diagnosis is suggested by the typical angiographic appearance⁵(Fig 1, 2) and confirmed by