Predictors of compliance with EVAR follow-up and its impact on reintervention and mortality

Abstract Objectives Numerous studies have demonstrated that compliance to surveillance protocols after endovascular aneurysm repair (EVAR) diminishes over time. Additionally, the survival benefit of strict adherence to surveillance is unclear. This study aimed to evaluate compliance and long-term mortality following EVAR. Methods We conducted a retrospective analysis of all EVAR patients (n=310) with expected follow-up treated between 01/2008 and 12/2020. Demographic data and potential risk factors for non-compliance were analyzed. Compliance was defined as verified follow-up at a maximum interval of 15 months. Results Overall, 118 patients (38.1 %) died during follow-up. At a median follow-up of 14 [IQR 2, 41] months, 40.3 % of patients were compliant to the follow-up regimen. The presence of endoleak did not significantly influence compliance (p=0.246), but compliance was linked to a higher risk of detected endoleak and reinterventions (p<0.01; p<0.001). Age, sex, marital status, assessed comorbidities, AAA diameter, rupture, urgency of the operation and travel distance to the hospital were not associated with compliance to follow-up. A multivariable time-dependent Cox model with compliance as a time-varying covariate showed non-compliance was linked to a lower hazard of death (p<0.001) with a significant time interaction (β=0.03, p<0.001), indicating a time-varying effect. The Kaplan–Meier analysis found no difference in survival between groups (p=0.105). Conclusions Our study showed no survival benefit for patients compliant to follow-up after EVAR. Competing risks analyses revealed higher rates of endoleaks and reinterventions among compliant patients reflecting more intensive surveillance and detection.