IYSC11 - Preliminary Study on the Use of Contrast Ultrasound in the Preoperative Workup of Patients Candidates for Carotid Endarterectomy

Objectives: The aim of our study was to prospectively preliminarily assess the use of the ultrasound signal amplifier in the preoperative color Doppler ultrasound study of carotid plaques in asymptomatic patients eligible for surgical correction in a single-centre experience.

Methods: Between November 2022 and May 2023, 21 patients with asymptomatic carotid stenosis eligible for surgery were enrolled. Each patient underwent a standard color Doppler ultrasound (DUS), contrast-enhanced ultrasound (CEUS), and computed tomography angiography (CTA) during the preoperative workup. Demographic data, clinical information, risk factors, comorbidities, and home therapy were collected for each patient. The degree of stenosis, according to NASCET criteria, was analyzed using DUS, CEUS, and CTA, employing the independent samples t-test. Differences between standard DUS and CEUS results were also analyzed for hemodynamic parameters (peak systolic velocity [PSV], end-diastolic velocity [EDV] PSV; EDV; internal carotid artery/common carotid artery [ICA/CCA] ratio) and plaque morphology, including the presence of juxtaluminal black areas (JBAs), discrete white areas (DWAs), and intraplaque neovascularization. Qualitative variables were compared using the χ2 test. Additionally, intraoperative information about the treatment type and plaque characteristics were documented.

Results: The average degree of stenosis, measured according to NASCET criteria, was significantly lower during DUS examination (68%) compared to CEUS (72%; p< 0.001). A significant difference was also observed between stenosis values obtained with CEUS and those measured in the CTA exam (80%; p=0.004). The mean PSV values measured during the CEUS exam were higher (249 vs. 321 cm/sec; p< 0.001), as were the EDV values (88 vs. 92 cm/sec; p< 0.001) and ICA/CCA ratio (3.8 vs. 4.4; p< 0.001).
Regarding morphological evaluation, the plaque in the DUS exam exhibited irregular margins in 8 cases, while in CEUS, this was observed in 15 cases. Furthermore, CEUS more frequently detected juxtaluminal black areas (JBAs) larger than 2mm (17 vs. 7, with a mean diameter of 3.3 vs. 2.7; p=0.4) and discrete white areas (DWAs) (6 vs. 0) compared to the standard exam. Finally, with CEUS, neovascularization within the studied plaque was visualized in 10 cases.

Conclusions: Despite being a preliminary experience with a limited patient sample, our study on the preoperative assessment of carotid plaques indicates that CEUS is a safe, cost-effective, and efficient non-invasive diagnostic tool. It offers higher resolution compared to DUS, though sharing some limitations with it. Moreover, CEUS appears to provide more accurate information than DUS regarding the intrinsic characteristics of carotid plaques and their embolic risk profile