PURPOSE: Catheter-directed therapy has been increasingly used in acute pulmonary embolism (PE). Whether ultrasound-assisted thrombolysis (USAT) is superior to standard catheter-directed thrombolysis (SCDT) remains unclear. This is a systemic review and meta-analysis of comparative trials on USAT and SCDT for PE to determine whether either modality yielded better clinical efficacy and safety. MATERIALS AND METHOD: Major databases including PubMed, Embase, Cochrane Central, and Web of Science were searched through March 16, 2023. Studies that reported outcomes of SCDT and USAT for acute PE were included. Studies reported data on therapeutic efficacy (a reduction in the right ventricle [RV]/left ventricle [LV] ratio, a reduction in the systolic pulmonary artery pressure [mm Hg], change in Miller index, length of intensive care unit [ICU] and hospital stay) and safety outcomes (in-hospital mortality, overall and major bleeding events). RESULTS: A total of 9 studies with 2610 patients were included in the meta-analysis. The analysis showed significantly greater improvement in the RV/LV ratio in the SCDT group than in the USAT group (mean difference [MD]: -0.155
95% confidence interval [CI]: -0.249 to -0.006). No statistically significant differences were found between groups comparing change in systolic pulmonary artery pressure (MD: 0.592 mm Hg
95% CI: -2.623 to 3.807), change in Miller index (MD: -4.1%
95% CI: -9.5 to 1.3%), hospital stay (MD: 0.372 days
95% CI: -0.972 to 1.717), and ICU stay (MD: -0.073.038 days
95% CI: -1.184 to 1). No significant difference was noted in safety outcomes, including in-hospital mortality (pooled odds ratio: 0.984
95% CI: 0.597 to 1.622), and major bleeding (pooled odds ratio: 1.162
95% CI: 0.714 to 1.894). CONCLUSIONS: In our meta-analysis of observational and randomized studies, USAT is not superior to SCDT in patients with acute PE.INSPLAY registration number: INPLASY202240082.Clinical ImpactThis study compared SCDT and USAT in patients with acute pulmonary embolism. We found no additional benefit in PA pressure change, thrombus reduction, hospital stay, mortality and major bleeding rate. Additional study using consistent treatment protocol is necessary for further investigation.