Comparison of endoleak diagnostic efficacy of contrast-enhanced ultrasound and computed tomography angiography after endovascular aneurysm repair for abdominal aortic aneurysm.

INTRODUCTION: Routine monitoring is necessary to detect endoleaks after treating abdominal aortic aneurysms (AAAs) with endovascular aneurysm repair (EVAR). Accurately diagnosing endoleak type is crucial to ensure a durable repair during secondary intervention. Computed tomography angiography (CTA) has been the standard for follow-up of patients following EVAR. Contrast-enhanced ultrasound (CEUS) became available to clinicians in the United States in 2021 and utilizes noniodinated contrast while minimizing radiation, which may prove beneficial for patients.

METHODS: Status post-EVAR patients being routinely monitored for endograft integrity, endoleak, and sac growth that were assessed by CEUS and CTA within 30 days of each other were retrospectively compared. Lumason was the contrast agent injected intravenously during real-time CEUS examination of the AAA sac and endograft. Endoleak detection and type, AAA sac size and volume compared with previous, stent graft integrity, and position and flow dynamics were determined and compared.

RESULTS: A total of 167 CEUS studies were performed in 95 consecutively enrolled post-EVAR patients with >1 cm/year sac expansion from February 2024 to December 2025 and reviewed by an experienced vascular radiologist. Forty-one CEUS exams from 38 patients had a comparable CTA within 30 days of the CEUS exam, and these patients retrospectively formed the patient population of this study. There was agreement in 27 of 41 CEUS-CTA pairs. CEUS and CTA endoleak diagnosis disagreed in seven patients. Three of the seven patients were found to have type 1 endoleak noted on CEUS and misdiagnosed by CTA, whereas one patient had type 3 endoleak and three patients had type 2 endoleak also misdiagnosed by CTA. CEUS achieved 97.14% sensitivity, 100% specificity, 100% positive predictive value (PPV), 85.71% negative predictive value (NPV), and area under the receiver operating characteristic curve (AUC) of 0.9857, outperforming CTA (78.57% sensitivity, 46.15% specificity, 75.86% PPV, 50% NPV, and AUC of 0.6621) (P = .0033). Mean AAA sac diameter measurements between CEUS and CTA were comparable (P = .277).

CONCLUSIONS: CEUS imaging outperformed CTA for endograft visualization and endoleak diagnosis, in line with similar European studies. Real-time temporal visualization of endoleaks and elimination of iodinated contrast with CEUS exams give endovascular surgeons a beneficial complement to CTA to detect endograft endoleaks and optimize endovascular treatments during long-term follow-up of post-EVAR patients with AAAs.