Endovascular and Hybrid Treatment of Extracranial Carotid Artery Aneurysms: Long Term Results from the International Carotid Aneurysm Registry

Objective: To evaluate the procedural and long term outcomes of endovascular treatment of extracranial carotid artery aneurysms (ECAAs). Methods: Within the prospective international Carotid Aneurysm Registry, patients with primary ECAA treated with endovascular or hybrid therapy were analysed. Hybrid therapy involved a combination of surgical correction of proximal elongation and distal stenting. Technical approach and follow up were determined locally. The primary endpoint was ECAA exclusion. Secondary endpoints included technical success, peri-procedural complications, stent patency, long term ipsilateral stroke, and death. Results: Between January 2014 and November 2024, 481 patients were included in the Carotid Aneurysm Registry. Of these, 42 patients (mean age 52 ± 17 years; 25 [60%] men) underwent elective endovascular ECAA exclusion (n = 37) or hybrid treatment (n = 5); 16 patients were symptomatic. One procedure was converted to open surgery due to technical failure. Thirty day outcomes revealed three ipsilateral strokes. One patient died of a stroke within 30 days. Follow up (median 65 months; interquartile range 28, 91) revealed 100% stent patency. ECAA exclusion was 95% at 12 months and 98% at a median of 65 months. One patient required additional coiling and another underwent re-stenting due to stent migration, both within the first year. During a median survival of 88 months, four patients died due to non-ECAA related causes. No ipsilateral stroke occurred in this timeframe. Conclusion: In this registry based, prospectively collected cohort, endovascular treatment of selected ECAAs seems technically feasible and effective for aneurysm exclusion. However, this treatment comes with high peri-procedural morbidity and mortality rates. Long term outcomes showed a high stent patency rate and successful ECAA exclusion during follow up. These findings should be counterbalanced against natural course and open surgical outcome data to design a future individualised treatment algorithm for patients with ECAA.