Jonathan D Beard
Peripheral vascular disease commonly affects the arteries supplying the leg and is mostly caused by atherosclerosis. Restriction of blood flow, due to arterial stenosis or occlusion, often leads patients to complain of muscle pain on walking (intermittent claudication). Any further reduction in blood flow causes ischaemic pain at rest, which affects the foot. Ulceration and gangrene may then supervene and can result in loss of the limb if not treated. The Fontaine score is useful when classifying the severity of ischaemia.
Although many patients with claudication remain stable, about 150-200 per million of the population progress to critical limb ischaemia (Fontaine III or IV) each year. Many patients with critical limb ischaemia can undergo revascularisation, which has a reasonable chance of saving the limb. A recent audit by the Vascular Surgical Society found a success rate of over 70% for these patients. However, many patients still require major amputation. Rehabilitation of elderly patients after amputation can prove difficult, with high community costs. Critical limb ischaemia has been estimated to cost over £200m a year in the United Kingdom.
A history of muscular, cramp-like pain on walking that is rapidly relieved by resting, together with absent pulses, strongly supports the diagnosis of intermittent claudication. Disease of the superficial femoral artery in the thigh results in absent popliteal and foot pulses and often causes calf claudication. Disease of the aorta or iliac artery results in a weak or absent femoral pulse, often associated with a femoral bruit. Disease at this level may cause calf, thigh, or buttock claudication.
The dorsalis pedis artery lies superficially on the dorsum of the foot, although its position varies considerably. The posterior tibial artery lies deeper behind the medial malleolus. Many healthy people have only one foot pulse. The popliteal pulse can be difficult to palpate in muscular patients. A prominent popliteal pulse suggests the possibility of a popliteal aneurysm.
Fontaine classification of chronic leg ischaemia
Stage I Asymptomatic
Stage II Intermittent claudication
Stage III Ischaemic rest pain
Stage IV Ulceration or gangrene, or both
Leg pain ? claudication
Resting ankle brachial pressure index
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