Large Aneurysm Size is Associated with Increased Short and Long Term Mortality after Branched and Fenestrated Repair for Thoraco-abdominal and Complex Abdominal Aortic Aneurysms.

Objective: This study assessed outcomes following fenestrated and branched endovascular aortic repair (F/BEVAR) for thoraco-abdominal aortic aneurysms (TAAAs) and complex abdominal aortic aneurysms (cAAAs) based on aneurysm size (small, medium, and large).

Methods: Patients who underwent elective F/BEVAR for the treatment of TAAAs and cAAAs (only juxtarenal aneurysms) from 2013 - 2022 in the Vascular Quality Initiative database were included. Aneurysm size was categorised as small (< 5.5 cm in men, < 5 cm in women), medium (5.5 - 7 cm in men, 5 - 7 cm in women), and large (≥ 7 cm). Demographics and outcomes were compared. Survival was evaluated using Kaplan-Meier curves and Cox regression.

Results: A total of 3 804 patients underwent F/BEVAR (small, n = 519; medium, n = 2 685; large, n = 600). Median patient age (small, 73 years; medium, 74 years; large, 76 years; p < .001), prior aortic repair (small, 14.3%; medium, 18.7%; large, 39.0%; p < .001), and treatment for extent II TAAA (small, 2.7%; medium, 8.5%; large, 14.0%; p < .001) differed statistically significantly between patient groups. Peri-operative mortality (small, 1.0%; medium, 2.3%; large, 4.0%; p = .004), any complication (small, 14.6%; medium, 20.0%; large, 19.3%; p = .018), stroke (small, 0.4%; medium, 0.9%; large, 2.3%; p = .003), and prolonged length of stay (small, 6.7%; medium, 13.3%; large, 17.5%; p < .001) differed statistically significantly by aneurysm size. Survival at 1 year (small, 95%; medium, 91%; large, 85%; p < .001) and 5 years (small, 87%; medium, 80%; large, 65%; p < .001) also differed statistically significantly. After adjustment, patients with large aneurysms had increased 30 day mortality (odds ratio [OR] 3.3, 95% confidence interval [CI] 1.3 - 10.1), long term mortality (hazard ratio [HR] 2.4, 95% CI 1.6 - 3.7), and prolonged length of stay (OR 1.87, 95% CI 1.2 - 2.9) compared with those with small aneurysms. Compared with patients with medium aneurysms, those with large aneurysms had increased 30 day mortality (OR 1.85, 95% CI 1.1 - 3.1) and long term mortality (HR 1.71, 95% CI 1.3 - 2.2).

Conclusion: Large aneurysm size was associated with increased short and long term mortality in patients undergoing F/BEVAR. Improved screening may provide opportunity for earlier identification in order to decrease adverse events following F/BEVAR for large TAAAs.