Ultrasound-Accelerated Catheter-Directed Thrombolysis for Acute Submassive Pulmonary Embolism

Purpose: To evaluate the safety and efficacy of ultrasound-accelerated catheter-directed thrombolysis (USAT) in patients with submassive pulmonary embolism (PE). Materials and Methods: This retrospective study comprised 45 consecutive patients (15 prospective, 30 retrospective) who underwent USAT for submassive PE from June 2012 May 2014. Inclusion criteria were right ventricular dysfunction (RVD) as indicated by right ventricle-to-left ventricle (RV:LV) ratio > 0.9, symptoms of < 2 weeks' duration, and absence of absolute contraindication to thrombolysis. All patients underwent pulmonary artery catheterization with a standardized protocol (24 mg recombinant tissue plasminogen activator). Hemodynamic evaluation immediately after USAT, RV:LV ratio evaluation at 48-72 hours after USAT by computed tomography angiography and echocardiography, and adverse event reporting for a minimum of 30 days were performed. Outcomes and complications are reported as per the Society of Interventional Radiology Reporting Standards for Endovascular Treatment of Pulmonary Embolism. Results: USAT was technically successful in 100% (n = 45) of patients. Main pulmonary artery pressure significantly decreased from 49.8 mm Hg to 31.1 mm Hg (P < .0001). RVD significantly improved with mean RV:LV ratios decreasing from 1.59 to 0.93 (P < .0001). There were 6 complications: 4 minor bleeding episodes at access sites and 2 major bleeding complications (flank and arm hematoma). All-cause mortality at 30 days was 0%. There were no readmissions for PE at 30 days after discharge. Conclusions: Ultrasound-accelerated catheter-directed thrombolysis using a standardized low-dose protocol is a safe and efficacious method of treatment of submassive PE to reduce acute pulmonary hypertension and RVD.