Objective: After endovascular aortic aneurysm repair (EVAR), the Society for Vascular Surgery recommends a computed tomography (CT) scan ≤30 days, followed by annual imaging. We sought to describe long-term adherence to surveillance guidelines among United States Medicare beneficiaries and determine patient and hospital factors associated with incomplete surveillance.
Methods: We analyzed fee-for-service Medicare claims for patients receiving EVAR from 2002 to 2005 and collected all relevant postoperative imaging through 2011. Additional data included patient comorbidities and demographics, yearly hospital volume of abdominal aortic aneurysm repair, and Medicaid eligibility. Allowing a grace period of 3 months, complete surveillance was defined as at least one CT or ultrasound assessment every 15 months after EVAR. Incomplete surveillance was categorized as gaps for intervals >15 months between consecutive images as or lost to follow-up if >15 months elapsed after the last imaging.
Results: Our cohort comprised 9695 patients. Median follow-up duration was 6.1 years. A CT scan ≤30 days of EVAR was performed in 3085 (31.8%) patients and ≤60 days in 60.8%. The median time to the postoperative CT was 38 days (interquartile range, 25-98 days). Complete surveillance was observed in 4169 patients (43.0%). For this group, the mean follow-up time was shorter than for those with incomplete surveillance (3.4 ± 2.74 vs 6.5 ± 2.1 years; P < .001). Among those with incomplete surveillance, follow-up became incomplete at 3.3 ± 1.9 years, with 57.6% lost to follow-up, 64.1% with gaps in follow-up (mean gap length, 760 ± 325 days), and 37.6% with both. A multivariable analysis showed incomplete surveillance was independently associated with Medicaid eligibility (hazard ratio [HR], 1.42; 95% confidence interval [CI], 1.29-1.55; P < .001), low-volume hospitals (HR, 1.12; 95% CI, 1.05-1.20; P < .001), and ruptured abdominal aortic aneurysm (HR, 1.51; 95% CI, 1.24-1.84; P < .001).
Conclusions: Postoperative imaging after EVAR is highly variable, and less than half of patients meet current surveillance guidelines. Additional studies are necessary to determine if variability in postoperative surveillance affects long-term outcomes.
Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.