Aneurysm Sac Expansion After EVAR: Associated Factors, Prognostic Impact, and Preventive Strategies—A Systematic Review and Meta-Analysis

Background/Objectives: Aneurysm sac expansion is an adverse marker of durability after endovascular aneurysm repair (EVAR). We assessed factors associated with expansion, its prognostic significance, and the effect of preventive embolisation.

Methods

PubMed/MEDLINE, Web of Science, and Scopus were searched through 23 August 2026 (PROSPERO CRD420261386132). Random-effects meta-analyses analysed odds ratios (ORs), hazard ratios (HRs), and risk ratios (RRs) separately; risk of bias and certainty were assessed with RoB 2, ROBINS-I, QUIPS, and GRADE.

Results

Thirty-three reports (20 independent quantitative studies) were included. Type II endoleak (OR 5.16, 95% confidence interval [CI] 2.53–10.50; HR 3.08, 95% CI 2.11–4.49) and type I endoleak (OR 11.94, 95% CI 5.30–26.90) were associated with expansion (low certainty). Expansion was associated with higher late mortality in a single independent adjusted cohort (HR 1.31, 95% CI 1.14–1.51; very low certainty). Preventive embolisation was associated with lower risks of persistent type II endoleak (RR 0.58, 95% CI 0.34–0.97; low certainty) and reintervention (RR 0.44, 95% CI 0.24–0.82; very low certainty), but neither association remained statistically conclusive in sensitivity analyses.