Fibromuscular Dysplasia

Introduction
Fibromuscular dysplasia (FMD) is currently defined as an idiopathic, segmental, non-inflammatory and non-atherosclerotic disease of the musculature of arterial walls, leading to stenosis of small and medium-sized arteries.[1] The prevalence of FMD is not precisely known. Several studies determined prevalence in arteriograms of potential kidney donors. Craig et al reviewed the results of 1,862 renal angiograms obtained in potential renal donors and found FMD in 71 patient (3.8%).[2] In another study of 159 potential renal donors, 7 had FMD (4.4%).[3] Blondin et al found four cases of fibromuscular dysplasia (3.9%) in 101 renal donors.[4] In 2012 first 447 patients were enrolled in The United States Registry for Fibromuscular Dysplasia. [5] No studies have investigated the prevalence of
Furthermore, medial type is divided into subtypes: medial fibroplasia (60%–70%); perimedial fibroplasia (15%–25%); medial hyperplasia (5%–15%).[1] Kincaid et al proposed an angiographic classification of FMD into three types: multifocal type, with multiple stenoses and the string-of-beads' appearance; the tubular type, with a long concentric stenosis; the focal type, with solitary stenosis less than 1 cm in length. The "string-of-beads" sign is the most suggestive and most frequent aspect of FMD.[9] The clinical presentation of FMD is determined primarily by the distribution of arteries that are affected and the type and severity of the vascular lesions. The most common clinical presentation of renal FMD is renovascular hypertension secondary to renal artery