Fibromuscular Dysplasia as a Cause of Renovascular Hypertension

The renal arteries of five patients with hypertension accompanied by radiologically demonstrable stenosis of the renal arteries were submitted to histological and histometrical examinations. Cases of arteriosclerotic stenosis of the renal artery were not included in the present study. Fibromuscular dysplasias were found in both hilar renal arteries and intrarenal ones, the latter of which caused poststenotic oligemia and provoked hypertension. Subadventitial fibroplasia was attributed to subadventitial hematoma due to medial weakness. Vascular fibroplasia was occasionally found in renal arterioles. In clinically confirmed ischemic area of the kidney there was no hypertensive arterial changes. The arterial muscular coat was found attenuated in such an area.