What is the treatment for a popliteal aneurysm?

Treatment of Popliteal Aneurysms

Popliteal aneurysms ≥2.0 cm in diameter should undergo surgical repair to reduce the risk of thromboembolic complications and limb loss. 1, 2

Diagnosis

• Patients with a palpable popliteal mass should undergo ultrasound examination to confirm the diagnosis 2
• Ultrasound is the initial diagnostic test of choice, using a linear array vascular probe (6-10 MHz) 1
• Patient positioning: reverse Trendelenburg or semi-sitting position with 30° hip flexion optimizes examination 1

Treatment Algorithm

For Asymptomatic Popliteal Aneurysms:

1. Size ≥2.0 cm: Surgical repair is indicated 2, 1

   • Rationale: Up to 50% of asymptomatic popliteal aneurysms become symptomatic within 2 years and 75% within 5 years 2
   • Complication rates are significantly higher in aneurysms >2.0 cm (14% vs. 3.1%) 2

2. Size <2.0 cm: Annual ultrasound surveillance 1

   • Growth rate: 0.7 mm/year for aneurysms <2.0 cm vs. 1.5 mm/year for larger aneurysms 2
   • Consider repair if rapid expansion or development of symptoms occurs

For Symptomatic Popliteal Aneurysms:

1. Acute thrombosis with limb ischemia:

   • Catheter-directed thrombolysis or mechanical thrombectomy to restore distal flow before definitive repair 1, 3
   • Thrombolytic therapy significantly improves graft patency (p<0.005) and limb salvage (p<0.01) compared to emergency surgery alone 3

2. Symptomatic with compression or chronic ischemia:

   • Prompt surgical repair 1

Surgical Options

Open Repair (Traditional Gold Standard):

• Bypass grafting with exclusion of the aneurysm 4
• Approach options:
  • Medial approach with bypass (most common)
  • Posterior approach (used in about 20% of cases) 4
• Graft material:
  • Autologous vein graft provides superior patency compared to prosthetic grafts (p<0.001) 4
  • Vein grafts are used in approximately 88% of open repairs 4

Endovascular Repair:

• Involves placement of stent grafts through the common femoral artery 5
• Best suited for patients with favorable anatomy (adequate landing zones) 5
• Consider for older patients or those with high surgical risk 6
• Advantages: shorter hospital stay (3.9 vs 9.5 days, p<0.001) 6
• Limitations: inferior patency rates, particularly in acute settings 4

Outcomes and Prognosis

Open Repair:

• 1-year secondary patency: 87-94% 4, 6
• 30-day amputation rate: 3.7% for acute cases 4
• Better long-term durability compared to endovascular repair 4

Endovascular Repair:

• 1-year secondary patency: 48-84% (lower in acute cases) 4, 6
• 30-day amputation rate: 14.8% for acute cases 4
• Postoperative clopidogrel therapy improves patency rates 5

Follow-up and Surveillance

• Antiplatelet therapy should be continued indefinitely unless contraindicated 1
• Regular follow-up to assess:
  • Return or progression of ischemic symptoms
  • Presence of distal pulses
  • Ankle-brachial indices (ABIs) 1

Important Considerations

• Approximately 50% of popliteal aneurysms are bilateral, requiring examination of both legs 1, 3
• About 60% of patients with popliteal aneurysms have concurrent abdominal aortic aneurysms, warranting additional screening 1
• Thromboembolic complications are much more common than rupture (rupture rates only ~7%) 1
• Underestimating the risk of thromboembolic complications and limb loss is a common mistake 1