Ultrasound-assisted thrombolysis in submassive and massive pulmonary embolism: assessment of lung obstruction before and after catheter-directed therapy.

PURPOSE: New treatment guidelines support the use of catheter-directed therapy for both massive and submassive pulmonary embolism (PE). This study examines the safety and effectiveness of ultrasound-accelerated (UA) thrombolysis, for which prompt treatment is warranted to rapidly resolve thrombus and restore cardiopulmonary function.

MATERIALS AND METHODS: We retrospectively reviewed ten consecutive, acute submassive/massive PE patients. All patients exhibited acute symptoms and computed tomography evidence of large thrombus burden and evidence of right-ventricular (RV) dysfunction and/or failure. Patients were followed-up with posttreatment echocardiography (n = 7) and CT (n = 9) to evaluate right heart dysfunction and thrombus burden, respectively. Thrombolytic treatment was performed in all patients using the EkoSonic Endovascular system. Clinical outcomes and complications, RV pressures, and thrombus removal were evaluated. Paired Wilcoxon signed-rank tests were performed to analyze the pretreatment and posttreatment measures; p < 0.05 was considered significant.

RESULTS: Median thrombolytic dose was 18.0 mg tissue plasminogen activator infused over 20.8 h. There was a significant decrease in pretreatment and posttreatment RV pressures (52.0-30.0; p < 0.01); there was a significant decrease in pretreatment and posttreatment Mastora obstructive indices (74-43; p < 0.01). All patients improved clinically shortly after treatment onset. All ten patients survived to discharge with a median intensive care (ICU) stay of 4 days and 14 hospital days.

CONCLUSION: UA thrombolysis is promising in massive and submassive PE treatment and shows safe results. Patients showed improved thrombus burden, and rapid improvement in right cardiac function, whereas minimizing bleeding risk and ICU time were minimized. This results of this study provide the foundation for future comparative studies in treatment of large PEs.