EVAR Follow-Up with Ultrasound Superb Microvascular Imaging (SMI) Compared to CEUS and CT Angiography for Detection of Type II Endoleak.

Marco Curti,Filippo Piacentino,Gabriele Piffaretti,Giulio Carcano,Andrea Coppola,Gianpaolo Carrafiello,Massimo Venturini,Anna Maria Ierardi,Federico Fontana,Christian Ossola,Antonio Basile,Matteo Tozzi,Paolo Marra

doi:10.3390/diagnostics12020526

Abstract

The aim of this study was to evaluate the usefulness of superb microvascular imaging (SMI) versus contrast-enhanced ultrasound (CEUS) and compared to computed tomography angiography (CTA) as a reference standard, for detection of type II endoleak during follow-up of endovascular abdominal aortic aneurysm repair (EVAR). Between April 2017 and September 2020, 122 patients underwent post-EVAR follow-up with CTA at 3 months and with ultrasound SMI and CEUS at 4 months from the EVAR procedure. Aneurysmal sac diameter and graft patency were evaluated; endoleaks were assessed and classified. Sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy were calculated both for SMI and CEUS and compared to CTA. Furthermore, the percentage of agreement and Cohen’s Kappa coefficient were calculated. CTA revealed 54 type II endoleaks. Ultrasound SMI and CEUS presented the same sensitivity (91.5%), specificity (100%), positive (100%), and negative (92.8%) predictive and accuracy (95.9%) value for detecting type II endoleak. The same percentage of agreement of 94.9% was found between SMI/CEUS, and CTA with a Cohen’s Kappa coefficient of 0.89. The diagnostic accuracy of SMI is comparable with CEUS in the identification of type II endoleaks after EVAR. Since SMI is less invasive, less expensive, and less time-consuming, this method may be considered to be a potential tool for monitoring patients after EVAR implantation.

Highlights

Nowadays, the endovascular treatment of abdominal aortic [1,2,3,4,5] and visceral aneurysms [6,7,8] with endoprosthesis represents the first therapeutic choice in many hospitals, less burdened by morbidity and mortality than surgery
Endovascular abdominal aortic aneurysm repair (EVAR) is burdened by a lower mortality and complication rate [21]; it requires a “life-long” FU in which imaging plays a key role to identify complications such as fractures or stent migration, thrombosis, infections, sac enlargement, and endoleaks [22]
An endoleak is defined as reperfusion of the aneurysmal sac and represents the “Achilles’ heel” of the procedure, being the most frequent complication after EVAR procedure [23,24,25], with a reported incidence around 45% [9]

Summary

Introduction

The endovascular treatment of abdominal aortic [1,2,3,4,5] and visceral aneurysms [6,7,8] with endoprosthesis represents the first therapeutic choice in many hospitals, less burdened by morbidity and mortality than surgery. Endoleaks are usually asymptomatic and may progress to aneurysm rupture [10]. For this reason, patients need a strict follow-up (FU). The ideal imaging modality in the evaluation of endoleaks should be economical, repeatable, safe, and accurate. Ultrasound-based techniques, such as color Doppler ultrasound [14] and, in particular, contrast-enhanced ultrasound (CEUS) are considered to be a valid alternative to CTA in EVAR FU; they are safe, not expensive, repeatable, and adequately accurate in the identification of endoleaks [9,15,16,17]

Objectives

Methods

Results

Conclusion