Predictive value of inferior mesenteric artery size in type 2 endoleak after endovascular abdominal aortic aneurysm repair—a systematic review and meta-analysis

Abstract Background Type II endoleak after endovascular aneurysm repair is the most common endoleak type. Identifying pre-operative anatomical features that could signal higher risk will improve surveillance post-procedure. This systematic review and meta-analysis evaluated the association between inferior mesenteric artery (IMA) diameter and type II endoleak. Methods MEDLINE and EMBASE were searched via OVID (1946/1974 respectively to January 2025), in line with the PRISMA statement, for adult patients undergoing endovascular aneurysm repair for infrarenal abdominal aortic aneurysm with reported pre-operative inferior mesenteric artery diameter and post-operative type II endoleak outcomes. Both retrospective and prospective observational studies were eligible. Meta-analysis via a random-effects model evaluated the pooled mean IMA diameter among patients with type II endoleak and the mean difference in IMA diameter between patients with and without endoleak. The risk of bias was assessed using the Newcastle–Ottawa scale. Results Twenty studies met inclusion criteria; ten provided extractable quantitative data for pooling (2176 patients; 532 type II endoleaks). Assessment with the Newcastle–Ottawa scale demonstrated that the studies had scores between 6 and 8 out of 9. The pooled mean inferior mesenteric artery diameter among cases with endoleak was 2.95 mm (95% CI 2.64–3.26 mm; p < 0.01; I 2 = 95%). The pooled mean difference in diameter between patients with and without endoleak was 0.50 mm (95% CI 0.36–0.64 mm; p < 0.01; I 2 = 62%), indicating larger arteries in those who developed type II endoleak. Substantial heterogeneity reflected differences in endoleak definitions, imaging protocols, and measurement methods. Subsequent sac expansion and the need for reintervention were not reported uniformly across all studies, and when reported, insufficient data were available regarding these outcomes and their relation to IMA diameter. Conclusion Larger pre-operative inferior mesenteric artery diameter was associated with an increased likelihood of type II endoleak after endovascular aneurysm repair. However, the clinical relevance of a 0.5 mm difference remains uncertain, particularly in view of potential inter-observer measurement variability. Multicentre randomised controlled trials are needed to define actionable thresholds for treatment, considering confounding factors and clinical significance of the endoleak.