Abstract
BackgroundThe management of acute submassive pulmonary embolism (ASPE) remains controversial. Recent studies using ultrasound assisted catheter-directed thrombolysis (USAT) have demonstrated significant improvement in right ventricular (RV) function in ASPE. The safety profile of this relatively new procedure is yet to be studied on a large scale. We present our first 15 cases of ASPE treated with USAT resulting in rapid improvement in right heart hemodynamics with no major bleeding complications.Methods15 patients were diagnosed with ASPE on CT angiography with emboli either in the pulmonary trunk or one of the two main pulmonary arteries along with an RV/LV ratio of more than 0.9. Intravenous heparin was initiated. RV function was evaluated on transthoracic echocardiogram (TTE) using pulmonary artery systolic pressure, RV/LV diameter ratio and fractional area change (FAC). Invasive hemodynamic assessment was performed followed by insertion of the EkoSonic Endovascular System (EKOS, Bothell, WA), a USAT device, into bilateral pulmonary arteries. T-PA was infused at the rate of 1mg/hr/catheter for 12 hours following which hemodynamic assessment was repeated and catheters removed. TTE measurements were repeated 48 hours after initial catheter placement. Bleeding complications were stratified using the GUSTO scale.ResultsPatient characteristics, hemodynamic measurements and bleeding complications are shown in the table. All 15 patients had improvement across all hemodynamic parameters. Reduction in RV/LV ratio and increase in FAC were noted on TTE in all 15 patients as well. Four moderate and zero major bleeding complications were seen.ConclusionsOur experience shows that USAT can be a safe and valuable tool in the treatment of ASPE with significant and rapid improvement in RV function. However, larger studies are needed to assess its long term safety and efficacy when compared to current standard of therapy.