Nonatherosclerotic Arterial Disorders of the Lower Extremities

A therosclerotic peripheral artery disease (PAD) is com- mon, estimated to affect 4.3% to 29% of the adult population.1,2 PAD is an important syndrome to identify promptly because it is associated with an increased risk of premature myocardial infarction, stroke, and all-cause mortality.3 The public has limited appreciation for the disorder and its associated risks, making awareness of this disorder a high priority.4 Conversely, nonatherosclerotic artery diseases of the lower extremities (nonatherosclerotic PAD [NAPADs]) represent a heterogeneous group of uncommon conditions (Figure 1).Given the frequency of symptoms of leg discomfort, these disorders must also be considered in the differential diagnosis of patients who may not have the classic profile of atherosclerosis.Although each condition has distinctive pathophysiology, clinical manifestations, treatment, and prognosis, NAPAD also has unifying characteristics.Furthermore, left undiagnosed or mismanaged, these conditions may result in seriously adverse outcomes that may otherwise have been avoided or minimized.