Key points

• Popliteal artery aneurysm is the most common lower limb aneurysm

• 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 popliteal and femoral artery aneurysms should undergo repair

• Asymptomatic popliteal artery aneurysms >2 cm in maximum diameter should be considered for elective repair

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

• Adequate imaging of the proximal and distal vasculature is vital for successful repair

Introduction

Popliteal artery aneurysms are the second most common peripheral arterial aneurysm and together with femoral artery aneurysms represent the vast majority of true lower limb arterial aneurysms. They frequently occur in association with aortic aneurysms and are often identified as an incidental finding during routine examination or radiological imaging. However, they may present with lower limb thromboembolism or rupture and thus their identification and subsequent management is vitally important to the patient's quality of life and life expectancy.

Pathophysiology

The majority of popliteal artery aneurysms (PAAs) develop secondary to a systemic atherosclerotic disease affecting the medial layer of the artery and are often associated with aneurysms elsewhere. In early retrospective studies in which PAAs were detected clinically or with the use of angiography rather than Duplex scanning, the incidence of PAAs in patients with aortic aneurysms was between 3.2 and 3.9%.