Endovascular abdominal aortic aneurysm repair (EVAR) outcomes of unibody and single/double docking limb endografts in Medicare beneficiaries between 2012 and 2018.

Objective: The evaluation of perioperative and long term outcomes for endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAA) using anatomic (unibody) and proximal neck fixated (docking limbs) endografts across consecutive time cohorts.

Design: This study compares the outcomes of EVAR in Medicare patients stratified by mode of fixation.

Methods: All patients who underwent EVAR between 2012 and 2018 were identified in the Medicare database. Anatomic fixation (AF) and proximal fixation (PF) grafts were differentiated using Current Procedural Terminology (CPT) codes. The AF population was divided into three-time cohorts based on iterative changes in graft design: Cohort 1: (01/01/2012-20/07/2014); Cohort 2: (21/07/2014-09/05/2016); and Cohort 3: (10/05/2016-31/12/2017). The PF cohort was similarly divided into these three periods. Outcomes were evaluated through 31/12/2020 and included all-cause mortality, aortic rupture, and aortic-related reintervention.

Results: 32,031 patients underwent EVAR during the study period; 4729 were AF and 27,302 were PF. There were more women (p < .001) and patients with peripheral vascular disease (PVD) (p < .001) in the AF group. There were no group differences in perioperative outcomes. In Cohort 1, there was a higher rate of reintervention (11.9% vs 7.6%; p < .001) and aortic rupture (5.3% vs 4.0%; p = .019) in the AF group compared to the PF group. In Cohort 2, reintervention, aortic rupture, and reintervention rates were similar between the two groups (p = NS). In Cohort 3, the reintervention and aortic rupture rates were similar between the two groups (p = NS).

Conclusion: The higher rates of aortic rupture and reintervention seen in the AF group in Cohort 1 when compared with the PF group did not persist in Cohorts 2 and 3. This suggests that improvements in graft design may have led to durability which is similar to that of PF grafts. However, late aneurysm related complications are inherent risks after EVAR and long-term surveillance remains necessary.