Type 3 Endoleaks in Complex Endovascular Abdominal Aortic Aneurysm Repair within the Vascular Quality Initiative.

Abstract Objective Type 3 Endoleaks (T3EL) following complex EVAR (c-EVAR) for abdominal aortic aneurysm have been historically difficult to study due to their relative rarity. Previous studies within standard infrarenal EVAR have found an association between T3EL and decreased survival. This study aims to evaluate the occurrence of T3EL in a national multicenter cohort, identify potential procedural characteristics associated with T3EL development, and determine their impact on clinical outcomes in c-EVAR. Methods A retrospective cohort review was conducted of elective c-EVAR for non-ruptured aneurysms within the Vascular Quality Initiative (VQI) between January 2010 and March 2020. The VQI standards define c-EVAR as suprarenal or pararenal AAA repaired with any thoracoabdominal repairs, fenestrated/branched repairs, parallel stent repairs, custom manufactured devices, and physician modified endografts. End-points assessed were rates of T3EL within c-EVAR, and impact of T3EL on reintervention and survival. Index endoleaks were defined as endoleaks discovered during index hospitalization. Incident endoleaks were defined as new endoleaks, that were not present at index hospitalization, discovered at follow-up. Results 4,070 c-EVAR cases were identified between January 2010 and March 2020, of which, 2,656 (65.2%) had appropriate follow-up data. Half the cohort had a modified or custom graft (n=2,055/4,070, 50.5%). Branches were employed in 3,687 patients (90.5%), while fenestrations and chimney techniques were documented in 13% (n=533) and 15.1% (n=613) respectively . The rate of index T3EL was 4.1% (n=167), and the rate of incident T3EL at follow-up was 0.04% (n=1). Devices categorized as either custom or physician modified were utilized more frequently in patients with index T3EL (78.4%, n=131/167) compared to patients without index T3EL (49.2%, n=1,924/3,903) (p Conclusions T3EL in c-EVAR remain relatively uncommon and are identified predominately at index hospitalization. Development of T3EL was associated with higher device modularity and modification, which suggests that as device technologies continue to advance and become more intricate the occurrence of T3EL may persist and continue to require evaluation. In this study, the presence of T3EL did not appear to have a statistically significant relationship with aortic reinterventions or survival, however these findings are not definitive due to low event rate numbers and high potential for Type 2 errors. Amid the theoretical risk of device fatigue and degeneration, continued evaluations of large cohorts at extended follow-up intervals and diligent reporting remain paramount.