Analysis Shows Efficacy of Treating Pulmonary Embolism With the Ekosonic Ultrasound-Accelerated Thrombolysis System

November 16, 2012—At the VEITH Symposium in New York City, Tod C. Engelhardt, MD, presented data demonstrating the efficacy of catheter-directed ultrasound-accelerated thrombolysis (USAT) using the EkoSonic endovascular system (Ekos Corporation, Bothell, WA) to rapidly reduce right ventricular dilatation and pulmonary clot burden among patients with both massive and submassive pulmonary embolism (PE).

Dr. Engelhardt reported findings from a retrospective analysis that included 42 patients (mean age, 58 years) with acute PE treated by USAT. Seven patients had massive PEs, and 35 patients had submassive PEs. Thirty-seven patients (88%) presented with bilateral PE. Treatment with USAT reduced right-to-left ventricular dimension (RV/LV) ratio from 1.4 ± 0.4 to 1.0 ± 0.2 (P < .001), as measured by computed tomography (CT) performed at 39 ± 23 hours. RV dysfunction was characterized by the RV/LV ratio. Thrombus burden, measured with the modified Miller Score, was reduced from 18 ± 5 to 10 ± 5 (P < .001) at follow-up CT.

In addition, the mean recombinant tissue plasminogen activator (tPA; alteplase) dose of 31.0 ± 16.6 mg was infused along with ultrasound over 19.0 ± 6.8 hours. Patients who were treated early in the series (n = 13) received an average total dose of approximately 45 mg tPA, while those later in the series (n = 29) received an average total dose of approximately 20 mg tPA (P ≥ .38). However, the earlier patients did not have a greater reduction in RV/LV ratio or Miller Score than later patients.

In terms of safety, there were no deaths and no systemic bleeding complications reported. However, there were four access site bleeding complications requiring transfusion and one suspected recurrent massive PE event. These complications were reported in the early higher-dose tPA group; no bleeding complications were reported in the low-dose group. The median length of stay was 1 day in the intensive care unit and 7 days in the hospital.

In the press release from the VEITH meeting, Dr. Engelhardt, who is chairman of cardiovascular and thoracic surgery at East Jefferson General Hospital in Metairie, Louisiana, commented, “Patients with PE are routinely treated using USAT (EkoSonic endovascular system) with tPA at East Jefferson General Hospital. Optimal patient outcomes are achievable with a low tPA dose, thus minimizing the risk of bleeding complications. It's time that hospitals across the globe look to these devices as an alternative to open surgery.”