ABSTRACT

OBJECTIVE To evaluate the effectiveness and safety of sonolysis using a low intensity 2 MHz pulsed wave ultrasound beam during carotid endarterectomy.

DESIGN Multicentre, phase 3, double blind, randomised controlled trial.

SETTING 16 European centres.

PARTICIPANTS 1004 patients (mean age 68 years; 312 (31%) female) were enrolled in the study between 20 August 2015 and 14 October 2020 until the interim analysis was performed.

INTERVENTIONS Sonolysis (n=507) versus sham procedure (n=497).

MAIN OUTCOME MEASURES The primary endpoint was the composite incidence of ischaemic stroke, transient ischaemic attack, and death within 30 days. The incidence of new ischaemic lesions on follow-up brain magnetic resonance imaging was the main substudy endpoint, and incidence of intracranial bleeding was the main safety endpoint.

RESULTS The results favoured the sonolysis group for the primary endpoint (11 (2.2%) v 38 (7.6%); risk difference −5.5%, 95% confidence interval (CI) −8.3% to −2.8%; P<0.001), as well as in the substudy for magnetic resonance imaging detected new ischaemic lesions (20/236 (8.5%) v 39/224 (17.4%); risk difference −8.9%, −15% to −2.8%; P=0.004). Sensitivity analysis resulted in a risk ratio for sonolysis of 0.25 (95% CI 0.11 to 0.56) for ischaemic stroke and 0.23 (0.07 to 0.73) for transient ischaemic attack within 30 days. Sonolysis was found to be safe, and 94.4% of patients in the sonolysis group were free from serious adverse events 30 days after the procedure.

CONCLUSION Sonolysis was safe for patients undergoing carotid endarterectomy and resulted in a significant reduction in the composite incidence of ischaemic stroke, transient ischaemic attack, and death within 30 days.

TRIAL REGISTRATION Clinicaltrials.gov NCT02398734