Nonatherosclerotic PAD: Approach to Exertional Pain in the Lower Extremities.

Atherosclerotic peripheral artery disease is the most common cause of intermittent claudication. Nonatherosclerotic peripheral artery disease is a heterogeneous collection of diseases affecting the extracoronary arteries which is not due to atherosclerosis. These diseases include, but are not limited to, popliteal artery entrapment syndrome, cystic adventitial disease, external iliac endofibrosis, and thromboangiitis obliterans. Due to its relatively low prevalence, nonatherosclerotic peripheral artery disease may be misdiagnosed leading to the mismanagement of potentially treatable conditions. The proper and timely diagnosis of these conditions is paramount to the prevention of adverse outcomes as treatments widely vary. The diagnostic approach to patients presenting with intermittent claudication must take into account both atherosclerotic as well as nonatherosclerotic causes of peripheral artery disease making the differential vital to clinical practice.