Contrast-Enhanced Ultrasonography for Detection of Endoleak After Endovascular Aortic Repair

Purpose: Endoleak is the most common complication after endovascular aneurysm repair (EVAR). Endoleak is often asymptomatic and is associated with an increased risk of poor outcomes. The current gold standard imaging modality for endoleak surveillance after EVAR is computed tomography angiography (CTA). Although effective, lifelong surveillance with CTA exposes patients to repeated doses of radiation and nephrotoxic contrast agents and is associated with substantial costs. Recently, contrast-enhanced ultrasonography (CEUS) has emerged as a viable alternative to CTA for long-term surveillance after EVAR.

Materials and Methods: A single-center retrospective cohort study was conducted on patients from 2017 to 2021 who had a history of abdominal aortic aneurysm treated with EVAR and imaging with both CTA and CEUS. Philips’ IntelliSpace PACS Radiology with Prism primordial search was used to identify patients who previously had CEUS screening for endoleak detection after EVAR. The study population included a sample size of 35 events in 28 patients. Positive and negative results for detection of endoleak by CEUS were tabulated as true positive, false positive, true negative, and false negative compared with those for CTA and angiography. These results were organized in two-by-two tables, and values for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated.

Results: Of 35 screening combinations, endoleak was detected in 26 cases by CTA and in 24 cases by CEUS. CEUS yielded a sensitivity of 96% and specificity of 100% when studied against CTA as the gold standard. CEUS showed a PPV of 100% and NPV of 92% compared against CTA. Sixteen of the 30 patients in the study population also underwent aortic angiography. When using CEUS as the gold standard, angiography showed 86% sensitivity, 50% specificity, 92% PPV, and 33% NPV. When using CTA as the gold standard, angiography yielded 87% sensitivity, 100% specificity, 100% PPV, and 33% NPV.

Conclusions: CEUS is a safe, accurate, and cost-effective imaging modality to evaluate for endoleak after EVAR. Given the reliable imaging quality, avoidance of radiation, lack of nephrotoxic contrast agents, ability to detect changes in real time, and cost-effectiveness, CEUS is a viable option for long-term surveillance after EVAR.