Key points

• Lower limb arterial aneurysms rarely occur in isolation

• The majority present either as an incidental finding or as lower limb ischaemia

• Aneurysm rupture is rare, but life- and limb-threatening when it occurs

• All symptomatic femoral artery aneurysms should undergo repair

• Asymptomatic femoral artery aneurysms >2.5 cm in maximum diameter should be considered for elective repair

True femoral aneurysms

Incidence

Femoral artery aneurysm (FAA) is the second most common peripheral artery aneurysm after popliteal artery aneurysms. They most often occur in male patients over 65 years with an age-adjusted incidence of combined femoral and popliteal artery aneurysms of 7.39 per 100,000 population in the USA; male-to-female ratio of 10:1. Patients with FAAs demonstrate a high incidence of cardiovascular disease and associated risk factors, including hypertension, smoking and hypercholesterolaemia. Diabetes mellitus appears to be ­protective for femoral artery aneurysm. Although FAAs predominantly occur in association with atherosclerotic disease, there are reports available in the English literature suggesting an association with vasculitides and connective tissue disorders.

FAAs rarely occur in isolation and are frequently associated with a contralateral aneurysm or/and aneurysmal disease affecting the aorta or other peripheral arteries. In a cohort of 100 patients with FAAs Graham et al. reported 72% were bilateral, 85% were associated with aorto-iliac aneurysms and 44% were associated with popliteal artery aneurysms. Alternatively, the incidence of FAAs in patients with abdominal aortic aneurysms is ≈5%.

Pathophysiology

The pathophysiological conditions predisposing to the development of FAAs are poorly understood.