Peripheral Arterial Disease

Lower-extremity peripheral arterial disease (PAD) is atherosclerotic, and sometimes thrombotic, narrowing of the aortoiliac, femoropopliteal, or infrapopliteal arteries. The narrowed vessel can supply resting muscle adequately but fail when exercise increases oxygen demand. That mismatch produces exertional symptoms; more advanced flow limitation causes pain even at rest and eventually tissue loss. The clinical spectrum matters because the urgency changes with the limb’s viability: - Asymptomatic PAD: objective arterial disease without reported limitation or pain. - Chronic symptomatic PAD: classic claudication or atypical exertional, non-joint leg symptoms. - Chronic limb-threatening ischemia (CLTI): ischemic rest pain lasting more than two weeks, a non-healing ulcer, or gangrene attributable to objectively documented PAD. - Acute limb ischemia (ALI): an abrupt reduction in arterial perfusion that threatens limb viability. Pain while walking alone does not define “advanced” PAD. Rest pain, ulceration, gangrene, sensory loss, or motor impairment carries greater clinical weight because these findings indicate that perfusion is inadequate for tissue survival or nerve and muscle function. PAD also signals a high probability of atherosclerosis in other arterial beds. A patient with PAD is therefore...