Peripheral arterial disease

The most common presentations of peripheral arterial disease are intermittent claudication and abdominal aortic aneurysm. In patients under 50 years of age the cause of disease is most likely to be genetic, congenital, immunological, infectious, or traumatic; over 50 years the principal risk factor is smoking.

Diagnosis—the main diagnostic method used to confirm the diagnosis of peripheral arterial disease is Doppler ultrasonography, in particular to estimate the ratio of systolic blood pressure at the ankle and in the arm, the ankle–brachial pressure index (ABPI; normal value 1.0–1.4, <0.9 abnormal). Ultrasonography is the standard technique for demonstrating abdominal aortic aneurysms, usually defined as being when the maximum aortic diameter exceeds 3 cm.

Critical leg ischaemia is defined as gangrenous change, ulceration, tissue loss, or rest pain lasting for 2 weeks, with an absolute ankle pressure of less than 50 mmHg.

Acute leg ischaemia

Presents as a painful, pale and pulseless limb, and is usually caused by thrombosis at the site of an atherosclerotic stenosis. Requires administration of analgesia and, if appropriate, rapid surgical intervention: (1) for irreversible ischaemia the options are amputation or palliative care; (2) for severe but potentially reversible ischaemia (white leg), surgery is usually the treatment of choice; and (3) for moderate limb ischaemia (no paralysis and only mild sensory loss), arteriography with consideration of thrombolysis, endovascular angioplasty/stenting, or surgical embolectomy/endarterectomy/bypass.

Chronic leg ischaemia

Most commonly presents with claudication affecting the calf and thigh. This is associated with high cardiovascular risk, but only 5% will go on to lose a limb, and surgical or endovascular intervention is not usually required. Key elements in management are smoking cessation, aspirin, and statins.

Abdominal aortic aneurysm

Ruptured abdominal aortic aneurysm typically causes collapse and severe back or abdominal pain: less than 20% reach hospital alive, and almost half of those undergoing emergency surgical die within 30 days.

By standard definition, more than 5% of men older than 55 years have an abdominal aortic aneurysm, but most of these are small (3–5.5 cm). These should be managed by ultrasound surveillance, with attention to modification of cardiovascular risk factors.

Repair is generally recommended for asymptomatic aneurysms greater than 5.5 cm (perhaps >5 cm in women), or symptomatic aneurysms of any size. Minimally invasive endovascular aneurysm repair has an operative mortality of about 2%, which is only one-third of that associated with traditional open repair, but within 2 years the mortality advantage of endovascular repair has been lost and long-term outlook is unknown.