Ultrasound-Assisted Catheter-Directed Thrombolysis for Submassive Pulmonary Embolism

PURPOSE: Catheter-directed thrombolysis (CDT) is a relatively new therapy for pulmonary embolism that achieves the superior clot resolution compared to systemic thrombolysis while avoiding the high bleeding risk intrinsically associated with that therapy. In order to examine the efficacy and safety of CDT, we conducted a retrospective cohort study of patients undergoing ultrasound-assisted CDT at our institution. METHODS: The charts of 30 consecutive patients who underwent CDT as a treatment of pulmonary embolism at our institution were reviewed. Risk factors for bleeding during thrombolysis were noted. Indicators of the right heart strain on computed tomography and echocardiogram, as well as the degree of pulmonary vascular obstruction, were recorded before and after CDT. Thirty-day mortality and occurrence of bleeding events were recorded. RESULTS: Nine (30%) patients had 3 or more minor contraindications to thrombolysis and 14 (47%) had major surgery in the month prior to CDT. Right ventricular systolic pressure and vascular obstruction decreased significantly after CDT. There was a significant decrease in the proportion of patients with right ventricular dilation or hypokinesis. Decrease in pulmonary vascular obstruction was associated with nadir of fibrinogen level. No patients experienced major or moderate bleeding attributed to CDT. CONCLUSION: Catheter-directed thrombolysis is an effective therapy in rapidly alleviating the right heart strain that is associated with increased mortality and long-term morbidity in patients with pulmonary embolism with minimal bleeding risk. Catheter-directed thrombolysis is a safe alternative to systemic thrombolysis in patients with risk factors for bleeding such as prior surgery. Future studies should examine the safety of CDT in patients with contraindications to systemic thrombolysis.