Renal artery stenosis: anatomic classification for percutaneous transluminal angioplasty.

Most lesions that decrease renal blood flow originate within the renal artery; however; large, aortic, atherosclerotic plaques can overhang the renal ostium producing a functional renal artery stenosis. At the Hospital of the University of Pennsylvania, 45 consecutive percutaneous transluminal angioplasties were examined retrospectively and classified as to site of the obstructing lesions and clinical outcome. Stenoses within the renal artery responded very well to angioplasty, with 83% of patients showing either an excellent or good result. Conversely, when aortic plaques were responsible for inflow obstruction, 76% of patients responded poorly or not at all to balloon dilatation. It is proposed that this disparity of response reflects the anatomic differences in the orientation of elastic and collagen fibers of the muscularis and advential layers of the renal artery and the aorta.