Type III endoleaks in complex endovascular abdominal aortic aneurysm repair within the Vascular Quality Initiative.

OBJECTIVE: Type III endoleaks (T3ELs) following complex endovascular aneurysm repair (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 T3ELs and decreased survival. This study aims to evaluate the occurrence of T3ELs 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 nonruptured aneurysms within the Vascular Quality Initiative (VQI) between January 2010 and March 2020. The VQI standards define c-EVAR as suprarenal or pararenal abdominal aortic aneurysms repaired with any thoracoabdominal repairs, fenestrated/branched repairs, parallel stent repairs, custom manufactured devices, and physician-modified endografts. End points assessed were rates of T3ELs within c-EVAR, and impact of T3ELs on reintervention and survival. Index endoleaks were defined as endoleaks discovered during index hospitalization. Incident endoleaks were defined as new endoleaks, which were not present at index hospitalization, discovered at follow-up.
RESULTS: A total of 4070 c-EVAR cases were identified between January 2010 and March 2020, of which 2656 (65.2%) had appropriate follow-up data. One-half of the cohort had a modified or custom graft (n = 2055/4070; 50.5%). Branches were employed in 3687 patients (90.5%), whereas fenestrations and chimney techniques were documented in 13% (n = 533) and 15.1% (n = 613), respectively. The rate of index T3ELs was 4.1% (n = 167), and the rate of incident T3ELs at follow-up was 0.04% (n = 1). Devices categorized as either custom or physician-modified were utilized more frequently in patients with index T3ELs (78.4%; n = 131/167) compared with patients without index T3ELs (49.2%; n = 1924/3903) (P < .001). Compared with those without T3ELs, the presence of index T3ELs was not statistically associated with increased aortic reinterventions or increased mortality.
CONCLUSIONS: T3ELs 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 T3ELs may persist and continue to require evaluation. In this study, the presence of T3ELs 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 II 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.