What are the patency rates for endovascular treatment of popliteal artery pseudoaneurysms?

Patency Rates for Endovascular Treatment of Popliteal Artery Pseudoaneurysm

Endovascular treatment of popliteal artery pseudoaneurysms achieves primary patency rates of 77-80% at 1 year and 70-77% at 2-5 years, with secondary patency rates of 86-90% at 1 year and 76-87% at 2-5 years.

Short-Term Patency Outcomes (1 Year)

• Primary patency at 1 year ranges from 77-100% across multiple series, with the most rigorous prospective cohort reporting 80% 1
• Secondary patency at 1 year is consistently 86-90% when aggressive reintervention protocols are employed 1, 2
• Technical success rates exceed 94-100% in experienced centers 3, 4
• The highest patency rates (100% at 1 year) are reported in smaller series with shorter follow-up, suggesting selection bias 3

Mid-Term Patency Outcomes (2-5 Years)

• Primary patency at 2 years is 77% in the largest prospective cohort with mean 24-month follow-up 1
• Secondary patency at 2 years reaches 87% when occlusions are managed with prompt reintervention 1
• Five-year data shows primary patency of 70% and secondary patency of 76% 2
• These rates are notably lower than surgical bypass with saphenous vein, which achieves >80% patency at 5 years 5

Critical Factors Affecting Patency

Antiplatelet Therapy is the Strongest Predictor

• Postoperative clopidogrel is the only significant predictor of stent-graft patency in multivariate analysis 1
• Introduction of aggressive dual antiplatelet protocols (aspirin plus clopidogrel) reduced occlusion rates from 35% to 20% 2
• Long-term single antiplatelet therapy with aspirin 75-100 mg/d or clopidogrel 75 mg/d should be continued indefinitely 6

Learning Curve and Technical Evolution

• Complication rates decreased significantly after the first 23 cases (61% vs 32%, P=0.016) in one series tracking the learning curve 2
• Early adoption of more aggressive anticoagulation protocols and improved patient selection contributed to better outcomes 2
• Technical improvements in stent-graft design and deployment techniques have incrementally improved results over time 1, 2

Reintervention Requirements

• Overall reintervention rate is 26% (19 of 73 limbs) during follow-up 2
• Stent-graft occlusion occurs in 18-25% of cases and accounts for the majority of reinterventions 1, 2
• Additional complications requiring reintervention include migration (9 cases), fracture (3 cases), and stenosis (2 cases) in one 73-patient series 2
• Secondary patency rates of 86-90% demonstrate that most occlusions can be successfully salvaged with prompt intervention 1, 2

Comparison to Open Surgical Repair

• Surgical repair with saphenous vein achieves superior long-term patency (>80% at 5 years) compared to endovascular treatment 5
• Open repair via posterior approach achieved 100% primary patency at mean 46-month follow-up in one surgical series 7
• Endovascular repair offers lower perioperative morbidity but requires more frequent reinterventions 1
• The ACC/AHA guidelines emphasize that saphenous vein grafts provide superior long-term patency and limb salvage rates for popliteal artery pathology 5

Clinical Context and Limitations

• Most published data addresses popliteal artery aneurysms rather than pseudoaneurysms specifically, though endovascular techniques are similar 1, 3, 4, 2
• Partially thrombosed aneurysms (72% of cases) may have different outcomes than simple pseudoaneurysms 4
• Patients presenting with acute ischemia have worse outcomes and require catheter-directed thrombolysis before definitive repair 5
• Mean follow-up in most series is relatively short (15-24 months), limiting long-term patency data 1, 3, 4

Key Pitfalls to Avoid

• Failing to initiate dual antiplatelet therapy perioperatively dramatically increases occlusion risk 1, 2
• Inadequate proximal and distal landing zones (poor quality seal zones) predict early failure 1
• Treating patients without optimizing distal runoff vessels first in the setting of acute thrombosis leads to persistent ischemia 5
• Using endovascular repair in young, active patients may be problematic given the need for multiple reinterventions over time 5