Contrast-enhanced Ultrasound after EVAR: Supplement and potential substitute for CT in early- and long-term follow-up.

AIMS: Endoleaks are the most common complication after EVAR. CTA is presently the golden standard for lifelong surveillance after EVAR. Several studies and meta-analyses have shown contrast-enhanced Ultrasound (CEUS) to be a good alternative. The main goal of our study was to further validate the inclusion of CEUS in follow-up examination protocols for the systematic surveillance after EVAR.

MATERIAL AND METHODS: A retrospective analysis of patients who had received CEUS as part of their routine surveillance after EVAR at our centre was conducted. Detection rate and classification of endoleak types were compared between available postinterventional CTA/MRA and follow-up CEUS examinations. Last pre-interventional CTAs before EVAR served as baselines with focus on potential co-factors such as age, BMI, maximum aortic aneurysm- diameters, endoleak orientation and distance-to-surface influencing detection rates and classification.

RESULTS: In total, 101 patients were included in the analysis. 44 endoleaks (43.5% of cases) were detected by either initial CEUS or CTA, mostly Type II (37.6% of the included patients). Initial CEUS showed an endoleak sensitivity of 91.2%, a specificity of 100%, a PPV 100% and an NPV of 84.6%. No covariate with an influence on the correct classification could be identified either for CEUS or CT.

CONCLUSIONS: CEUS should be considered a valid complementary method to CTA in the lifelong surveillance after EVAR. As Type II endoleaks seem to be a common early-term, sometimes spontaneously resolving complication that can potentially be missed by CTA, we suggest combined follow-up protocols including CEUS in the early on post-interventional assessment.