Peripheral Vascular Disease

Lower-extremity peripheral artery disease (PAD) is usually caused by atherosclerotic or thrombotic narrowing in the aortoiliac, femoropopliteal, or infrapopliteal arteries. At rest, the narrowed circulation may deliver enough oxygen to the muscles. During walking, however, muscle demand rises faster than blood flow can increase. The result is reproducible aching, cramping, or fatigue—usually in the calf, but sometimes in the thigh, buttock, or foot—that improves with rest. This is intermittent claudication. As arterial disease progresses, perfusion may become inadequate even without exercise. Chronic limb-threatening ischemia (CLTI) is the chronic syndrome of ischemic rest pain, nonhealing wounds, or gangrene. Acute limb ischemia (ALI) is different: it is a sudden reduction in limb perfusion caused by thrombosis, embolism, or abrupt arterial occlusion. CLTI threatens tissue over time; ALI can threaten the limb within hours. PAD is not merely a leg disorder. Objectively confirmed disease indicates systemic atherosclerosis and increases the risk of myocardial infarction, stroke, cardiovascular death, and limb loss. A patient who reports no leg pain may still have asymptomatic PAD and substantial cardiovascular risk. Diabetes, tobacco use, chronic kidney disease, older...