Percutaneous mechanical thrombectomy using the AcoStream thrombus aspiration system for intermediate-high-risk...

Intermediate-high-risk pulmonary embolism (PE), characterized by right ventricular (RV) dysfunction and elevated cardiac biomarkers without hemodynamic instability, carries a substantial risk of clinical deterioration. While catheter-directed thrombolysis (CDT) is effective, it carries inherent bleeding risks. Large-bore mechanical thrombectomy (MT) has emerged as a promising alternative, but its real-world efficacy and safety require further validation. Therefore, we retrospectively reviewed consecutive patients with acute intermediate-high-risk PE who underwent MT using the AcoStream system.

Between July 2021 and February 2025, 45 patients diagnosed with acute intermediate-high-risk PE who underwent MT using the AcoStream system were retrospectively analyzed. Efficacy outcomes included immediate and early improvements in the angiographic total Miller index, pulmonary artery systolic pressure (PASP), gas exchange (PaO₂/FiO₂ ratio), vital signs (heart rate), and tissue perfusion (lactate levels). Additionally, the post-procedural right ventricular/left ventricular (RV/LV) diameter ratio at 48 hours was evaluated. Safety outcomes included major bleeding and clinically relevant non-major bleeding (CRNMB) defined by the International Society on Thrombosis and Haemostasis (ISTH) criteria.

Following the procedure, the median total Miller index decreased significantly from 16.00 [interquartile range (IQR), 15.00, 18.00] to 6.00 (IQR, 5.00, 8.00) (P<0.001), accompanied by an immediate reduction in PASP from 46.00 mmHg (IQR, 41.00, 50.00) to 30.00 (IQR, 26.00, 32.00) mmHg (P<0.001). Gas exchange and physiological parameters improved profoundly, with the PaO2/FiO2 ratio increasing from 260.00 (IQR, 204.00, 286.00) to 381.00 (IQR, 367.00, 395.00) mmHg (P<0.001), heart rate decreasing from 104.00 to 80.00 bpm (P<0.001), and lactate dropping from 1.90 to 1.50 mmol/L (P<0.001). In the subgroup with echocardiographic data (n=34), the median RV/LV ratio was 0.91 (IQR, 0.87, 0.97) at 48 hours post-procedure. No major bleeding events (0.0%) occurred during hospitalization or follow-up. CRNMB occurred in 3 patients (6.7%) and was managed conservatively.

MT using the AcoStream system was associated with favorable short-term procedural and hemodynamic observations in patients with acute intermediate-high-risk PE. Given the observational design and lack of a comparator group, these findings should be considered hypothesis-generating and require confirmation in larger prospective studies.