Impact of the Lumbar Arteries on Aneurysm Diameter and Type 2 Endoleak after Endovascular Aneurysm Repair

Background: Prophylactic embolization of the inferior mesenteric artery (IMA) during endovascular aneurysm repair (EVAR) is recommended to prevent type 2 endoleak (T2EL). However, the impact of patent lumbar arteries (LAs) on T2ELs and aneurysm diameter has not been elucidated. Methods: Fifty-seven consecutive patients who underwent EVAR at our institution between January 2013 and September 2022 and whose IMA had been occluded preoperatively or newly occluded postoperatively were included in the study. Predictive factors for aneurysm sac enlargement, sac shrinkage, and T2EL were investigated. Results: T2ELs occurred in 22.8% of the patients. The 4-year cumulative incidence rates of sac enlargement and shrinkage were 6.7% and 64.6%, respectively. The number of postoperative patent LAs was identified as a risk factor for T2ELs (95% confidence interval [CI]: 1.54-12.7, P = 0.0065). The number of postoperative patent LAs was found to be a significant predictor of sac enlargement (adjusted hazard ratio [AHR] 3.15, 95% CI: 1.43-6.96, P = 0.0045) and shrinkage (AHR 0.63, 95% CI: 0.43-0.91, P = 0.014). Conclusions: The current study demonstrated that the number of postoperative patent LAs had a significant impact on the development of T2ELs and the change in aneurysm diameter in patients in whom the IMA was occluded after EVAR.