Endovascular Aortic Repair Follow up Protocol Based on Contrast Enhanced Ultrasound Is Safe and Effective

Abstract

Objectives: The aim of this study was to define the safety and effectiveness of a contrast enhanced ultrasound (CEUS) based follow up for endovascular aortic repair (EVAR) surveillance at a mid-term period (4 years).

Methods: At the tertiary referral centre EVAR surveillance was based on plain abdominal radiograph and duplex ultrasound (CDU), with computed tomography angiography (CTA) reserved for any non-diagnostic imaging during the period 1999-2011 (Group A). From 2012, CEUS was performed when (a) any endoleak was detected at CDU, (b) sac growth > 5 mm within 6 months, and routinely for (c) patients with renal insufficiency (above Stage 3 chronic kidney disease), or (d) iodine contrast allergy (Group B).

Results: A total of 880 patients (mean age 75.6 ± 8.4 years; 824 male) who underwent EVAR between 1999 and 2015 and with a minimum of 1 year follow up were included. Six hundred and nineteen patients were in Group A (70%) and the remaining 261 in Group B (30%). Median follow up was 48 months (interquartile range 24-84). During the study period 318 CEUS scans were performed with no related complications. Indications for CEUS were the following: (a) 160 (50%) endoleak presence, (b) 34 (11%) significant sac expansions, (c) 91 (29%) renal insufficiency (Stage 3 or above CKD), and 33 (10%) iodine contrast allergies. CEUS was compared with CTA, with additional confirmation by angiographic and operative findings in the case of repair in the first 100 patients. CEUS had 100% sensitivity and 100% specificity in classifying endoleaks. No differences in endoleak, re-interventions and sac shrinkage percentage were seen between the two groups at 4 years. A 4 year analysis of CTA use found a 90% reduction with the introduction of CEUS.

Conclusions: The introduction of a CEUS based protocol for EVAR follow up was safe and effective and it was similar to the previous CTA based follow up protocol with regard to identification of endoleaks in a mid-term period. Moreover, CEUS allowed for 90% reduction of CTA, thereby decreasing radiation exposure for patients.

Keywords: Abdominal aortic aneurysm; Computed tomography angiography; Contrast-enhanced ultrasound; Endoleaks; Endovascular aortic repair; Endovascular aortic repair follow-up.