RS13 - Widespread Surveillance Failure Following Endovascular Aortic Aneurysm Repair in Current U.S. Practice

Objectives: Sex-based outcome disparities have been documented following abdominal aortic aneurysm (AAA) repair; however, the underlying mechanisms driving these findings remain undefined. The purpose of this study was to document whether there are sex-based disparities with post-operative imaging surveillance compliance following endovascular aortic aneurysm repair (EVAR) and, if so, to determine their impact on patient outcomes.

Methods: All patients with Medicare fee-for-service insurance undergoing elective EVAR in the Vascular Quality Initiative (VQI) Medicare-Linked Vascular Implant Surveillance and Interventional Outcomes Network (VISION) from 2010-2019 were identified. Patients with intraoperative completion endoleaks were excluded. Surveillance failure was defined as non-compliance with Society for Vascular Surgery (SVS) guidelines, which recommend follow-up imaging at 30-days, 1-year, and then annually thereafter. Long-term surveillance failure was examined with Kaplan Meier analysis and Cox proportional hazards models for risk adjustment. We performed a two-step adjustment to examine the mediator effect of surveillance failure on sex-based outcomes.

Results: Over the study interval, 15,008 patients met inclusion criteria. Among this group, 19.1% (N=2,873) were female. Notably, 18% of both male and female patients failed to undergo any surveillance imaging at 30-days post-procedure. Over the longer term, women demonstrated significantly higher rates of imaging failure (unadjusted HR 1.12, 95%CI 1.04–1.22; P=0.002) (Figure). Prior to adjustment, women had a significantly increased risk of death following EVAR compared to men (HR 1.29 95%CI 1.2-1.39; P< 0.001), however following the adjustment of all baseline variables, this effect was smaller (HR 1.08, 95%CI 0.99-1.17; P=0.05). While imaging failure was an independent risk factor for mortality (HR 1.25, 95%CI 1.15-1.36; P< 0.001), it did not appear to mediate the impact of sex on mortality when added in risk adjustment (HR 1.08, 95%CI 0.99-1.17; P=0.07).

Conclusions: Durable EVAR outcomes are less likely among women compared to men in current practice. Based on the current results, surveillance failure does not appear to be a mediator of the impact of sex on mortality but is a significant independent risk factor for mortality. Efforts designed to enhance compliance with post procedural imaging surveillance in all patients may be an opportunity to improve current AAA care delivery however may not address sex-based disparities in outcomes.