Diagnostic accuracy of contrast-enhanced ultrasound versus duplex ultrasound and computed tomography angiography for endoleak detection after EVAR: a prospective comparative study

Background Lifelong imaging surveillance after endovascular aneurysm repair (EVAR) is essential for endoleak detection but is limited by cumulative radiation and nephrotoxicity from computed tomography angiography (CTA). Contrast-enhanced ultrasound (CEUS) has emerged as a promising alternative, although prospective comparative data remain limited. Methods In this prospective, single-centre diagnostic accuracy study, 30 consecutive patients (mean age 78.5 ± 7.1 years; 70% male) undergoing EVAR follow-up were evaluated with duplex ultrasound (DUS), CEUS (SonoVue®), and CTA within a 30-day interval. CTA served as the reference standard. Diagnostic performance metrics were calculated with 95% confidence intervals (CIs) according to STARD recommendations. Results Endoleaks were identified in 11 patients (36.7%). CTA detected 8 cases (26.7%), CEUS 9 (30.0%), and DUS 4 (13.3%). CEUS demonstrated high sensitivity (87.5%; 95% CI 47.3–99.7%) and specificity (90.9%; 70.8–98.9%), with overall accuracy of 90.0% (73.5–97.9%). In contrast, DUS showed limited sensitivity (33.3%; 9.9–65.1%) despite perfect specificity (100%), yielding lower accuracy (73.3%). Inter-modality agreement was 83.3%. Conclusions CEUS demonstrates high diagnostic accuracy for endoleak detection after EVAR and represents a robust, radiation-free alternative to CTA for longitudinal surveillance. Given its favourable safety profile and diagnostic performance, CEUS should be considered a first-line imaging modality in routine follow-up, with CTA reserved for equivocal findings or pre-interventional planning. These results support a paradigm shift toward CEUS-based surveillance strategies.