Large-bore Mechanical Thrombectomy for Treatment of Intermediate-high Risk Pulmonary Embolism: A Single-center Australian Experience

Large-bore mechanical thrombectomy is an emerging treatment for intermediate-high-risk pulmonary embolism. We report outcomes from an Australian cohort.

A retrospective analysis compared patients with intermediate-high-risk pulmonary embolism, defined according to the 2019 European Society of Cardiology guidelines, who were managed before large-bore mechanical thrombectomy implementation (May 2023-April 2024) with those treated with large-bore mechanical thrombectomy (May 2024-October 2025) at a teaching hospital within a multidisciplinary pulmonary embolism response team framework. The primary endpoint was procedural feasibility and safety. Secondary endpoints included hemodynamic changes, intensive care unit utilization and 30-day mortality.

Sixty-seven patients were included: 24 treated with large-bore mechanical thrombectomy (median age 66.5, interquartile range 51.8-73.0 years; 58.3% male) and 43 treated with anticoagulation and/or thrombolysis (median age 76.0, interquartile range 65.5-82.5 years; 34.9% male). Technical success was 100%. Mean pulmonary arterial pressure decreased from 28.5 ± 8.7 to 21.2 ± 5.6 mmHg (p < 0.001). Heart rate and respiratory rate improved at 24 hours (both p < 0.001), although adjusted analyses showed no significant between-group differences in hemodynamic changes. Intensive care unit length of stay was shorter in the large-bore mechanical thrombectomy group (20.1 ± 7.9 vs 32.2 ± 17.3 hours, p = 0.003), with multivariable analysis confirming an independent 43% reduction (exp(β) = 0.57, 95% confidence interval 0.42-0.79, p = 0.001). No major bleeding events or deaths within 30-days occurred in the large-bore mechanical thrombectomy group, compared with two major bleeding events (4.7%) and three mortalities (7.0%) in the non-large-bore mechanical thrombectomy group.

Large-bore mechanical thrombectomy appears to be a safe and feasible treatment modality for intermediate-high-risk pulmonary embolism and was associated with reduced intensive care unit utilization compared with conventional therapies. These findings are hypothesis-generating and require validation in larger, prospective studies.