Role of Contrast-Enhanced Ultrasound in the Follow-Up after Endovascular Abdominal Aortic Aneurysm Repair

Background: The aim of this study was to assess whether contrast-enhanced ultrasound (CEUS) shows a false negative rate close to zero and therefore is suitable as the main non-invasive follow-up strategy for long-term monitoring after endovascular aortic repair (EVAR). Methods: We included all consecutive patients who underwent CEUS as follow-up after EVAR at our center between January 2017 and December 2021.The follow-up protocol consisted of Duplex ultrasound (DUS) with CEUS at 1, 3, 6 months postoperatively and every 6 months thereafter. Results: A total of 125 patients underwent 228 CEUS. The aneurysm sac showed shrinkage in 80 (64%) patients, stability in 32 (25.6%), and enlargement in 13 (10.4%). A total of 29 (23.2%) patients showed type 2 endoleak, 6 (4.8%) patients showed type 1 endoleak and 3 (2.4%) patients showed type 3 endoleak. Thirteen patients underwent one or more reinterventions. The sensitivity of CEUS vs. DUS was 100% vs. 75% (p > 0.0001). In classifying type 2 endoleak, CEUS compared to DUS showed a sensitivity of 93.2% vs. 59.4% and a specificity of 99.3% vs. 99.3%. CEUS showed a higher sensitivity compared to DUS in the detection of type 2 endoleak. CEUS permits the identification of a subset of patients requiring a stricter follow-up protocol.