Intraoperative contrast-enhanced ultrasound for early diagnosis of endoleaks during endovascular abdominal aortic aneurysm repair

Background: The aim of this study was to evaluate the feasibility and utility of intraoperative contrast-enhanced ultrasound (CEUS) for early detection of endoleaks (ELs) during endovascular abdominal aortic aneurysm repair (EVAR) compared with completion digital subtraction angiography. Methods: Patients undergoing elective EVAR from January 2017 to April 2018 were consecutively enrolled in this prospective study. After endograft deployment, two-digital subtraction angiography (2DSA) with orthogonal C-arm angulations (anteroposterior and sagittal view) were routinely performed. After the endovascular treatment of clear, high-flow type I/III ELs detected by 2DSA, intraoperative CEUS was carried out in sterile conditions on the surgical field before guidewire removal. Presence and type of EL were evaluated with 2DSA and CEUS. CEUS was performed with the vascular surgeon blinded to the 2DSA findings. The primary end point was the level of agreement between 2DSA and CEUS to detect any type of EL and type II EL. Agreement between two diagnostic methods was calculated using Cohen's kappa. The secondary end point was utility of CEUS for intraoperative adjunctive procedure guidance. Results: Sixty patients were enrolled (mean age, 78 ± 6 years; 90% male). 2DSA revealed 11 ELs (18%; 1 type IA, 10 type II), and CEUS 25 ELs (42%; 2 type IA, 23 type II). 2DSA and CEUS were in agreement in 39 cases (65%; 32 no ELs, 7 type II ELs). CEUS detected 17 ELs not identified by 2DSA (28%; 2 type IA, 15 type II); 2DSA detected three ELs not identified by CEUS (5%; 3 type II). In one case, 2DSA and CEUS detected type II and type IA ELs, respectively. For EL and type II EL detection, Cohen's kappa was 0.255 and 0.250, respectively (both “fair agreement”). Intraoperative adjunctive sac embolization was performed under CEUS control in 4 cases and technical success was 100%. Conclusions: Intraoperative CEUS during EVAR is feasible and can detect a greater number of ELs than 2DSA, in particular type II ELs. Further studies are necessary to assess the reliability of this intraoperative diagnostic examination. In type II ELs, CEUS may represent an additional, useful tool for intraoperative sac embolization guidance.