Endograft Thrombosis as an Indication for Open Conversion after Endovascular Aneurysm Repair in a Multicenter Experience over 25 Years

Background: To describe the outcomes of aortic endograft thrombosis (AET) as an indication for open conversion (OC) after endovascular aortic aneurysm repair (EVAR) in a multicenter experience. Methods: This study retrospectively analyzed cases of OC for AET following EVAR across 12 Italian Vascular Surgery centers from 1997 to September 2022. The end points were as follows: 30-day mortality and major postoperative complications. Follow-up data included survival and aortic-related complications. Results: Sixteen patients (mean age: 68.6 ± 8.5 years) were included. The median elapsed time between EVAR and OC was 26.46 months (interquartile range: 13.8-45.9). Proximal aortic cross-clamping site was supraceliac in 8 out of 16 (50%) patients, and complete removal of the stentgraft was achieved in 75% of cases (12/16 patients). Reconstructions were aorto-bi-iliac grafts in 8 cases (50%), 7 aortobifemoral bypass grafts (43.8%), and 1 aortoaortic tube graft (6.3%). All patients were symptomatic at presentation (68.7% unilateral acute limb ischemia, 25% bilateral acute limb ischemia, 1 patient had chronic severe claudication). Thirty-day mortality was 12.5% (2/16 patients). The overall morbidity rate was 43.8% (7 of 16 patients). No specific risk factors for early mortality were found. The overall estimated survival rate was 80.4% at 1 year, 62.5% at 2 years, and 41.7% at 3 years. Conclusions: OC for AET is typically reserved for complex cases that are not amenable to endovascular solutions. The frequent need for suprarenal clamping and complete endograft removal seems to be associated with high short-term mortality.