Predictors of compliance with surveillance after endovascular aneurysm repair and comparative survival outcomes.

OBJECTIVE

Although imaging surveillance is mandatory for all patients after endovascular aneurysm repair (EVAR), many patients are not compliant with follow-up. We sought to determine predictors of compliance with EVAR surveillance and to examine how compliance with current surveillance protocols correlates with survival.

METHODS

We analyzed 188 patients who underwent EVAR at our institution for infrarenal abdominal aortic aneurysms (AAAs) between 2001 and 2011. The primary end point was compliance with post-EVAR surveillance recommendations. Univariate analysis included patient demographics and socioeconomic information, AAA characteristics, EVAR hospital course variables, late complications and secondary interventions, length of follow-up, smoking status, family history of AAA, driving distances, primary care providers, and medical comorbidities. Mortality was determined by the Social Security Death Index. Multinomial logistic regressions were fit to identify independent predictors of compliance. Survival plots were generated with the Kaplan-Meier method and compared with the log-rank test. Univariate and multivariate Cox regression analysis was used to determine effect of compliance on survival after adjusting for confounders.

RESULTS

Of 188 patients, 89 (47.3%) were 100% compliant with follow-up visits and imaging, 21 (11.1%) were moderately compliant by missing appointments, and 78 (41.4%) were lost to follow-up completely. Overall median age was 74 years, and 81.9% of patients were male. Late complications occurred in 77 patients (40.9%), secondary interventions were performed in 32 patients (17%), and 5-year mortality was 21.2%. Mean follow-up interval was >40 months for 100% compliant and moderately compliant patients and <20 months for those lost to follow-up (P < .0001). In adjusted analysis, late complications (odds ratio [OR], 2.71; 95% confidence interval [CI], 1.32-5.55; P = .007), absence of social work consultation (OR, 2.43; 95% CI, 1.12-5.27; P = .024), and family history of AAA (OR, 2.67; 95% CI, 1.06-6.75; P = .037) were associated with 100% compliance, whereas shorter driving distances (P = .051) and shorter hospital stay (P = .056) approached significance. Transient ischemic attack or stroke (OR, 3.59; 95% CI, 1.18-10.91; P = .024) was the only variable independently associated with moderate compliance. Compared with patients lost to follow-up, 100% compliant patients had worse survival (log-rank test, P = .033), whereas moderately compliant patients' survival was not significantly different (log-rank test, P = .149). In adjusted Cox regression analysis, 100% compliant patients had decreased survival duration (rate ratio, 2.67; 95% CI, 1.18-6.06; P = .018) compared with those lost to follow-up.

CONCLUSIONS

Follow-up surveillance is incomplete for more than half of patients who undergo EVAR at our institution, and patient compliance can be predicted by covariates mentioned before. Compliance with current surveillance regimens does not confer a survival benefit. Further research individualizing surveillance protocols based on risk level of late complications and noncompliance and prospective studies examining resulting survival benefits of compliance are warranted.