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.