Characteristics of Popliteal Artery Aneurysms
Popliteal artery aneurysms are characterized by a strong male predominance, bilateral occurrence in approximately 50% of cases, surgical intervention recommended for aneurysms ≥2.0 cm in diameter, and a natural history of thromboembolism rather than rupture. 1, 2
Rupture Risk
- Unlike abdominal aortic aneurysms, popliteal artery aneurysms rarely rupture
- The natural history is one of thromboembolism or thrombosis, not expansion and rupture 1
- Studies show rupture rates are very low (approximately 7%) 1
- Rupture is described as "distinctly unusual" in the literature 1
- While rare cases of rupture have been reported, they are often misdiagnosed due to their rarity 3
Gender Distribution
- Popliteal aneurysms show a strong male predominance 2
- The vast majority occur in men 1
- They do NOT occur equally in both sexes
Size and Surgical Intervention
- Surgical indications include ALL symptomatic aneurysms and asymptomatic aneurysms ≥2.0 cm in diameter 2
- Annual ultrasound monitoring is recommended for asymptomatic aneurysms <2.0 cm 2
- The American College of Cardiology recommends surgical repair for popliteal artery aneurysms ≥2.0 cm to reduce thromboembolic complications and limb loss 2
- Early surgical intervention for asymptomatic aneurysms shows significantly better outcomes than waiting until symptoms develop 4
Bilateral Occurrence
- Approximately 50% of popliteal aneurysms are bilateral 1, 2
- This is an important diagnostic clue when evaluating patients with acute limb ischemia 2
- Studies consistently report bilateral occurrence in about half of cases 1
Associated Conditions
- Approximately 50% of popliteal aneurysms are associated with other aneurysms, primarily abdominal aortic aneurysms 1
- Coexistent abdominal aortic aneurysms have been reported in 62% of patients with popliteal aneurysms 1
- Screening for contralateral popliteal aneurysms and abdominal aortic aneurysms is recommended 2
Complications and Clinical Significance
- At least 40% of popliteal aneurysms are symptomatic on discovery due to thrombosis or distal emboli 1
- Complications occur in 36% of patients whose aneurysms are merely observed 1, 2
- The cumulative incidence of ischemic complications can reach 70% during 5-10 years of follow-up 1, 2
- Thromboembolic complications are much more common than rupture 1
Management Approach
- Ultrasound is the initial diagnostic test of choice 2
- Surgical options include bypass grafting, aneurysmectomy with graft interposition, or endovascular exclusion 4
- In acute ischemia, catheter-directed thrombolysis may be beneficial to restore distal flow 2
- Early elective treatment of asymptomatic aneurysms shows better outcomes than emergency intervention 5