Preoperative risk factors for aneurysm sac expansion caused by type 2 endoleak after endovascular aneurysm repair.

Purpose The objective of this study was to investigate the preoperatively definable risk factors which predict the aneurysm sac expansion caused by persistent type 2 endoleak after endovascular aneurysm repair. Methods Between 2008 and 2014, retrospective analysis was performed to examine the predictive risk factors for aneurysm sac enlargement caused by persistent type 2 endoleak, which was defined as a continuous endoleak present for more than six months. Aneurysm sac expansion was diagnosed if the maximum transverse diameter increased by 5 mm or more compared with the preoperative measurement. Results During the study period, endovascular aneurysm repair was performed in 211 patients with abdominal aortic aneurysm and common iliac artery aneurysm. Sac enlargement for type 2 endoleaks was observed in 20 patients (9.5%). The presence of more than five patent lumbar arteries flowing into aneurysm sac in the preoperative computed tomography (hazard ratio, 3.37; 95% confidence interval, 1.24-10.8; p = 0.017) was a predictive factor for sac expansion caused by persistent type 2 endoleak on Cox regression analysis. The presence of a patent inferior mesenteric artery was not associated with the sac expansion caused by persistent type 2 endoleak. Conclusions The presence of more than five lumbar arteries flowing into the aneurysm sac was a preoperative risk factor for sac expansion caused by persistent type 2 endoleak.