Ultrasonographic Surveillance of Abdominal Aortic Endovascular Aneurysm Stent Graft Repair in a Dedicated Vascular Laboratory

Abstract

Surveillance following abdominal aortic endovascular aneurysm repair (EVAR) is imperative to confirm graft patency, analyze residual sac size (RSS), and evaluate for complications. This retrospective study evaluated ultrasonographic (US) surveillance after EVAR compared to computed tomography (CT). US was done by 1 of 11 experienced registered technologists. US was ordered for surveillance more frequently than CT, with a ratio of 4:1. Compared to CT, US endoleak evaluations were 74% sensitive and 76% specific with a 63% positive predictive value and 84% negative predictive value. However, 11 CT scans were likely false negatives, and 1 CT was a false positive. For true positives that stated endoleak type, there was a 93% agreement between the type on US and CT. US had a 75% accuracy for RSS (95% CI, −1.02 to 1.16). These data support the use of US along with clinical symptoms as a first-line surveillance program after EVAR and are widely applicable to the majority of vascular laboratories that employ multiple registered vascular technologists. The adaptation of increased US surveillance would decrease the number of CT scans, thereby significantly reducing cost and radiation/contrast exposure to patients.