OBSTRUCTIVE PERIPHERAL ARTERIAL DISEASE
Most commonly caused by atherosclerosis of the vessels supplying the lower extremity.
Affects 15% of the U.S. adult population older than age 65 years.
Stenosis or obstruction of the large arteries to the lower extremities leading to supply–demand mismatch, initially with exertion, but may progress to occur at rest.
Intermittent claudication with exertional muscle pain or fatigue, critical limb ischemia with rest pain or tissue compromise, and acute limb ischemia.
Cutaneous findings from hypoperfusion range from dry skin, hair loss, and malformed toenails to ulceration and gangrene.
Peripheral arterial disease (PAD) occurs when atherosclerosis causes stenosis or occlusion in the distal aorta and large arteries of the lower abdomen, pelvis, and legs. Patients may be asymptomatic, experience exertional ischemic leg symptoms (intermittent claudication), or develop critical limb ischemia. The most classic symptom of PAD is intermittent claudication, which is usually described as pain, fatigue, or tiredness in a defined muscle group distal to the diseased vascular segment upon walking that is relieved by rest. The location of the pain differs depending on the anatomical location of the arterial lesions. Because the disease is most common in the distal superficial femoral artery, patients most commonly present with claudication in the calf muscle area (the muscle group just distal to the arterial disease). When the disease affects the more proximal aortoiliac vessels, thigh and buttock muscle claudication predominates. The discomfort tends to be highly reproducible within the same muscle groups and is precipitated by the same level of exertion. It is crucial to determine the amount of walking distance, a standard measure that quantifies severity and response to treatment, before the onset of symptoms. Resolution within several minutes of rest is an expected finding. Patients with inadequate collateral circulation may complain of cold extremities, hyperesthesia, rest pain, discolored toes, or skin breakdown. Ischemic rest pain typically affects the foot and may interfere with sleep or necessitate sleeping with the leg in a dependent position. Peripheral edema may then occur.
Although atherosclerotic obstructive PAD has a prevalence of only 3% in patients 40 to 59 years of age, this rises to up to 20% in the older than age 65 years group. This translates into approximately 8.5 million cases in the United States, and this number is expected to increase along with aging demographics.1-3 PAD is often unrecognized clinically, and more than one-half of all patients are asymptomatic. Gender predisposition shows preponderance in males, although the incidence in females rises rapidly after menopause. Anatomically, superficial femoral artery disease predominates, with development of symptoms typically in the seventh decade. Interestingly, symptoms from aortoiliac disease usually present a decade earlier.
Acute limb ischemia secondary to vessel thrombosis or embolism presents more dramatically with (a) severe pain, usually persistent at rest, (b) pallor, (c) pulselessness, (d) paresthesias, and (e) paralysis (the “5 Ps”). ...