Underutilization of Routine Ultrasound Surveillance after Endovascular Aortic Aneurysm Repair

Background: Since 2009, the Society for Vascular Surgery has advocated annual surveillance imaging with ultrasound (US) after the first postoperative year for uncomplicated endovascular aneurysm repairs (EVARs). We sought to describe diffusion of US into long-term routine surveillance and to estimate potential cost savings among Medicare beneficiaries after EVAR. Methods: Using Medicare claims data, we identified patients receiving EVAR from 2002 to 2010 and included only those who did not subsequently have reinterventions, late aneurysm-related complications, or death. We collected all relevant postoperative imaging (computed tomography [CT] and US) through 2011. Patients with follow-up less than 1 year were excluded. We estimated cost savings with increased use of US after the first postoperative year. Results: The cohort comprised 24,615 patients with a mean follow-up of 3.9 +/- 2.3 years. Mean number of images decreased from 2.23 in the first postoperative year to 0.31 in the 10th year. Utilization of US at the first postoperative year remained low but increased from 15.2% in 2003 to 28.8% in 2011 (P < 0.001). By the 10th postoperative year, the proportion of patients receiving US increased from 8.2% to 37.8%, while use of CT only remained high but decreased from 60.8% to 42.1%. Mean cost of surveillance imaging was $2,132/CT and $234/US. Performing US in 50-75%of patients beginning 1 year after EVAR would decrease costs by 14-48%/ year. This translates to a mean cost savings of $338-$1135 per imaged patient per year, with an estimated savings to Medicare of $155 million to $305 million over 10 years. Conclusions: CT remains the primary modality of surveillance for up to 10 years after EVAR for patients without reinterventions or aneurysm-related complications. Increasing the use of US and decreasing the use of CT would save cost without compromising outcomes.