Color Doppler Ultrasound with Superb Microvascular Imaging Compared to Contrast-enhanced Ultrasound and Computed Tomography Angiography to Identify and Classify Endoleaks in Patients Undergoing EVAR

Background: The aim of the study was to evaluate the diagnostic effectiveness of color Doppler ultrasound (CDUS) with superb microvascular imaging (SMI) compared to contrast-enhanced ultrasound (CEUS), computed tomography (CT) multislice angiography (64 slices), and angiography required for therapeutic reasons, for follow-up after endovascular aneurysm repair (EVAR). Methods: From March 2014 to May 2015, 57 patients treated with EVAR were evaluated with CT, CEUS, CDUS, SMI, and angiography in cases requiring treatment. Evaluation included sac diameter, stent-graft integrity, identification, and classification of endoleaks. Sensitivity, specificity, accuracy, and negative and positive predictive values were evaluated for each modality of endoleak identification. Results: Eight endoleaks (16.3%), all type II, were documented. Sensitivity of CT, CEUS, CDUS and SMI was 88%, 100%, 63%, and 75%, respectively. Specificity of CT, CEUS, CDUS, and SMI was 100%, 100%, 96%, and 98%, respectively With SMI, CDUS sensitivity significantly increased, whereas specificity did not register great differences. Conclusions: SMI was more accurate than CDUS but less accurate than CEUS and CT to identify endoleaks after EVAR. SMI could be concretely used in the follow-up phase to increase CDUS accuracy especially in patients who cannot be studied with CEUS or CT.