Fibromuscular Dysplasia

Fibromuscular dysplasia (FMD) is an idiopathic, segmental, nonatheromatous, and noninflammatory disease of the arterial walls, leading to stenosis, occlusion, aneurysm, dissection, and/or tortuosity of medium-sized arteries. Diagnosis is primarily radiographic with well-described histopathologic correlates. Though FMD commonly affects renal and cervical cerebrovascular arteries, FMD involving arteries of the upper and lower extremities, mesenteric arteries, and coronary arteries has also been described. This review covers epidemiology, etiology, and risk factors; histopathologic and radiographic classification; clinical presentation; differential diagnosis; radiographic evaluation; and treatment, including medical therapy, revascularization, and counseling. Tables outline the histologic and radiographic classification schemes for FMD and indications for renal artery and cerebrovascular revascularization in FMD based on the American Heart Association scientific statement. Figures show the radiographic appearance of FMD, coronary artery dissection, duplex ultrasonography of the renal artery, classic “string-of-beads” appearance, internal carotid artery, renal artery stent, and a smal