Impact of the Patency of Inferior Mesenteric Artery on 7-Year Outcomes After Endovascular Aneurysm Repair

Purpose: The impact of preoperative patent inferior mesenteric artery (IMA) on late outcomes following endovascular aneurysm repair (EVAR) remains unclear. This study aimed to investigate the specific influence of IMA patency on 7-year outcomes after EVAR. Materials and Methods: In this retrospective cohort study, 556 EVARs performed for true abdominal aortic aneurysm cases between January 2006 and December 2019 at our institution were reviewed. Endovascular aneurysm repairs performed using a commercially available device with no type I or type III endoleak (EL) during follow-up and with follow-up >= 12 months were included. A total of 336 patients were enrolled in this study. The cohort was divided into the patent IMA group and the occluded IMA group according to preoperative IMA status. The late outcomes, including aneurysm sac enlargement, reintervention, and mortality rates, were compared between both groups using propensity-score-matched data. Results: After propensity score matching, 86 patients were included in each group. The median follow-up period was 56 months (interquartile range: 32-94 months). The incidence of type II EL at discharge was 50% in the patent IMA group and 19% in the occluded IMA group (p<0.001). The type II EL from IMA and lumbar arteries was significantly higher in the patent IMA group than in the occluded IMA group (p<0.001 and p=0.002). The rate of freedom from aneurysm sac enlargement with type II EL was significantly higher in the occluded IMA group than in the patent IMA group (94% vs 69% at 7 years; p<0.001). The rate of freedom from reintervention was significantly higher in the occluded IMA group than in the patent IMA group (90% vs 74% at 7 years; p=0.007). Abdominal aortic aneurysm-related death and all-cause mortality did not significantly differ between groups (p=0.32 and p=0.34). Conclusions: Inferior mesenteric artery patency could affect late reintervention and aneurysm sac enlargement but did not have a significant impact on mortality. Preoperative assessment and embolization of IMA might be an important factor for improvement in late EVAR outcomes. Clinical Impact The preoperative patency of the inferior mesenteric artery was significantly associated with a higher incidence of sac enlargement and reintervention with type II endoleak following endovascular aneurysm repair, even after adjustment for patient background. Preoperative assessment and embolization of inferior mesenteric artery might be an important factor for improvement in late EVAR outcomes.