Imaging Surveillance Adherence After Endovascular Abdominal Aortic Aneurysm Repair at VA Hospitals.

Importance: Guidelines recommend annual imaging surveillance after endovascular abdominal aortic aneurysm repair (EVAR). How these guidelines translate into practice among veterans remains poorly described. Objective: To characterize post-EVAR surveillance among veterans. Design, Setting, and Participants: This retrospective cohort study evaluated veterans who underwent EVAR between January 1, 2000, and December 31, 2023, at US Department of Veterans Affairs (VA) hospitals and received follow-up care at VA and non-VA hospitals and imaging centers with payment via Medicare or the VA. Veterans treated with EVAR in VA hospitals during the study period were included. Exposure: Years after EVAR. Main Outcomes and Measures: The primary outcome was annual surveillance adherence, measured as 1 or more imaging studies in the abdomen or pelvis each year after EVAR. Stepwise logistic regression modeling was used to determine factors associated with poor adherence. Secondary outcomes were imaging type (cross-sectional, ultrasonography, or ultrasonography followed by cross-sectional imaging) and factors associated with lower adherence. Results: The cohort included 27 792 veterans (27 624 male [99.4%]; 22 521 aged ≥65 years [81.0%]). Mean (SD) follow-up was 6.0 (4.0) years. The mean (SD) proportion of time that veterans were surveillance adherent was 71.1% (28.5%). Surveillance was initially high, with 25 026 of 27 792 veterans (90.0%) undergoing surveillance imaging in year 1 after EVAR. However, this proportion decreased further out from EVAR, with 12 401 of 21 384 veterans (58.0%) undergoing surveillance imaging by year 4 after EVAR. Veterans were most likely to undergo imaging with computed tomography scans (21 911 veterans [78.8%]). However, the proportion with surveillance via ultrasonography alone increased from 823 of 25 026 veterans (3.3%) in year 1 after EVAR to 2567 of 12 401 veterans (20.7%) in year 4 after EVAR. White race (odds ratio [OR] vs all other racial groups, 0.84; 95% CI, 0.72-0.98), married status (OR vs all other social status categories, 0.80; 95% CI, 0.71-0.89), having a service-connected disability (OR, 0.69; 95% CI, 0.62-0.77), and a higher Charlson Comorbidity Index score (OR per 1-unit increase, 0.93; 95% CI, 0.91-0.95) were associated with lower odds of poor surveillance adherence. Conclusions and Relevance: In this study, post-EVAR imaging surveillance was high, although surveillance lapses were more likely further out from EVAR and for patients with certain characteristics. This information may inform future patient-centered efforts to improve post-EVAR imaging adherence.