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.