When to Repair a Popliteal Aneurysm
All popliteal aneurysms ≥2.0 cm in diameter should undergo surgical repair, regardless of symptoms, to prevent thromboembolic complications and limb loss. 1
Size-Based Repair Threshold
- Aneurysms ≥2.0 cm require elective repair because they carry a 14% complication rate compared to only 3.1% for smaller aneurysms 1
- Aneurysms >2.0 cm grow at 1.5 mm/year versus 0.7 mm/year for smaller ones, supporting early intervention 1
- The 2 cm threshold is consistently supported across multiple surgical series showing superior outcomes with elective repair 2, 3, 4
Additional Indications Beyond Size
Repair is indicated for any popliteal aneurysm with:
- Presence of mural thrombus on ultrasound due to embolic risk 1
- Associated distal tibioperoneal occlusions suggesting previous emboli 1
- Any symptomatic aneurysm (acute ischemia, chronic ischemia, rupture, compressive symptoms) regardless of size 1, 3
Surveillance for Small Aneurysms (<2.0 cm)
- Asymptomatic aneurysms <2.0 cm can be monitored with annual ultrasound 1
- However, 31% of small untreated aneurysms eventually require intervention due to symptoms or expansion beyond 2.0 cm 1
- Close surveillance is critical because these aneurysms can rapidly become symptomatic 2
Urgency: Why Delaying Repair Is Dangerous
The natural history of untreated popliteal aneurysms strongly favors early repair:
- 50% of asymptomatic popliteal aneurysms become symptomatic within 2 years 1, 5
- 75% become symptomatic within 5 years 1, 5
- Delaying repair until symptoms develop dramatically worsens outcomes: 56% of patients experience persistent distal ischemia despite repair, and 19% require amputation due to prior emboli destroying runoff vessels 1, 5
- Symptomatic aneurysms have worse secondary graft patency (74%) compared to asymptomatic aneurysms (100%) 3
Contraindications to Immediate Repair
The only reasonable contraindication is prohibitive surgical risk or limited life expectancy from medical comorbidities, but even then the threshold for repair should remain low 1
Mandatory Screening Before Repair
All patients with popliteal aneurysms require imaging to exclude:
- Contralateral popliteal aneurysm (50% are bilateral) 1, 5, 4
- Abdominal aortic aneurysm (50% have associated AAA) 1, 5
Common Pitfalls to Avoid
- Do not wait for symptoms to develop before repairing aneurysms ≥2.0 cm—outcomes are significantly worse once complications occur 1, 3
- Do not rely on size alone—presence of thrombus or distal occlusions mandates repair even if <2.0 cm 1
- Do not forget bilateral screening—missing a contralateral aneurysm can lead to future limb-threatening complications 1, 4