“Large Diameter” Aortic Endografts are Associated With Aneurysm Sac Expansion

Background: The purpose of this study was to evaluate the association between aortic endograft diameter and long-term outcomes following endovascular aneurysm repair (EVAR) performed in accordance with manufacturer instructions for use (IFU). Methods: A retrospective review of consecutive patients undergoing on-IFU EVAR (2000–2018) was performed to facilitate a comparative analysis of long-term patient outcomes based on device diameter. “Large diameter” devices were defined as >34 mm. The primary outcome of interest was freedom from sac expansion throughout long-term follow-up. Analyses included standard bivariate analyses, Kaplan–Meier with log-rank comparison, and Cox proportional hazards multivariate analysis. Results: A total of 1,099 underwent on-IFU EVAR from 2000–2018. Follow-up data were available for 980 patients. Of these, 75 patients (7.6%) were treated with >34-mm devices. There were no significant differences in demographics or comorbidities between the 2 groups, although preoperative abdominal aortic aneurysm size was greater in patients undergoing implantation of >34-mm devices (58 ± 8.5 mm vs. 56 ± 17.4 mm; P = 0.05). Median follow-up was 10.3 years. Patients with grafts >34 mm had reduced freedom from sac expansion throughout follow-up (P = 0.038). There were no significant differences in reintervention rates, open conversion, or rupture when stratified by graft diameter. A multivariate Cox regression identified patient age, preoperative abdominal aortic aneurysm size, need for reintervention, and use of >34-mm endografts as independent factors associated with expansion. Conclusions: The use of large diameter aortic endografts is associated with higher rates of sac expansion during long-term follow-up. Although there is undoubtedly a role for large diameter graft use in selected patients, it is important to recognize that these devices were typically approved post hoc without the same regulatory scrutiny of smaller endografts. These findings underscore the importance of ongoing surveillance for patients treated with >34-mm grafts, irrespective of compliance with manufacturer IFU.