Aneurysm Wall Enhancement Detected by Contrast Computed Tomography Scan Is Associated With Aneurysm Shrinkage After Endovascular Aneurysm Repair for Abdominal Aortic Aneurysm.

Background: Aneurysm expansion, and consequent endoleaks, after endovascular aneurysm repair (EVAR) is a major problem. Accurate prediction of aneurysm expansion is demanding for surgeons and remains difficult. Methods and Results: We retrospectively analyzed 157 cases of EVAR for abdominal aortic aneurysm (AAA) using a bifurcated main-body stent-graft. There were 62 cases of aneurysm shrinkage after EVAR, 63 cases of stable aneurysm, and 32 cases of aneurysm expansion. Type I endoleaks were significantly increased in the aneurysm expansion group (EXP) compared with the stable (STB) and shrinkage (SHR) groups (EXP: 15.6% vs. STB: 4.8% vs. SHR: 0%, P=0.005). Type II endoleaks were also significantly increased in EXP (EXP: 65.6% vs. STB: 36.5% vs. SHR: 6.5%, P<0.001). Aneurysm wall enhancement (AWE) on imaging, however, was significantly decreased in the EXP group (EXP: 18.8% vs. STB: 23.8% vs. SHR: 53.2%, P<0.001). In multivariate analysis, the occurrence of type II endoleaks significantly decreased (P<0.001) and that of AWE significantly increased the likelihood of aneurysm shrinkage (P=0.032). Conclusions: AWE following EVAR may be associated with aneurysm shrinkage.