Preoperative Abdominal Aortic Aneurysm Diameter Is Associated with Long-Term Durability After Endovascular Aortic Aneurysm Repair: A Multicenter Real-World Italian Cohort Study

Objective: To assess whether baseline abdominal aortic aneurysm (AAA) diameter is associated with long-term durability after elective EVAR, after accounting for relevant anatomic differences. Methods: Consecutive patients undergoing elective EVAR for infrarenal fusiform AAA between 2011 and 2022 at four Italian centers were analyzed. Ruptured, saccular, and adjunctive proximal or distal procedures were excluded. Patients were stratified as AAA ≤ 50 mm or >50 mm. Outcomes included any endoleak, reintervention, aneurysm-related death, sac behavior, and all-cause mortality. Analyses used cumulative incidence functions, Fine–Gray competing-risk models, multivariable Cox regression, and propensity-score matching incorporating key anatomic variables. Results: Among 1505 patients, 499 (33.2%) had AAA ≤ 50 mm. Median follow-up was 49 months. Larger aneurysms showed higher 10-year cumulative incidence of any endoleak (33.9% vs. 15.8%, Gray p < 0.001), type 1a endoleak (16.5% vs. 6.1%, Gray p < 0.001), reintervention (24.7% vs. 16.2%, Gray p < 0.001), and aneurysm-related death (5.4% vs. 2.4%, Gray p = 0.028). In anatomy-adjusted multivariable Cox models, each 1 cm increase in diameter was associated with higher hazards of any endoleak (HR 1.22, 95% CI 1.11–1.34; p < 0.001), type 2 endoleak (HR 1.26, 95% CI 1.12–1.43; p < 0.001), reintervention (HR 1.19, 95% CI 1.07–1.32; p = 0.001), and aneurysm-related mortality (HR 1.46, 95% CI 1.19–1.81; p < 0.001). In propensity-score-matched analyses, AAA ≤ 50 mm was associated with lower hazards of any endoleak, HR 0.39, 95% CI 0.28–0.55; p < 0.001, and reintervention, HR 0.40, 95% CI 0.26–0.62; p < 0.001. Conclusions: Baseline AAA diameter adds prognostic information beyond standard anatomic features and may help tailor post-EVAR surveillance. What is new?: This multicenter real-world study shows that baseline abdominal aortic aneurysm diameter provides continuous prognostic information of clinical outcomes after elective EVAR. Larger preoperative diameter was associated with higher long-term risk of endoleak and reintervention, supporting the use of baseline sac size as one component of individualized post-EVAR surveillance planning.