Catheter-directed, ultrasound-assisted thrombolysis is a safe and effective treatment for pulmonary embolism, even in high-risk patients.

Abstract

We sought to assess the early success and safety of catheter-directed, ultrasound-assisted (CDUA) thrombolysis for acute pulmonary embolism (PE) in patients deemed to be "high risk" for thrombolytic therapy. A retrospective evaluation of patients who underwent CDUA pulmonary thrombolysis in our practice during 39 months is reported. There were 91 patients considered, all of whom presented with acute PE as diagnosed by computed tomography angiography. The ratio of the right ventricle to left ventricle diameter (RVaxial:LVaxial) was noted, as were preprocedure pulmonary artery pressures (PAPs). Demographic data, significant medical history, and procedure details were recorded. Standard thrombolysis protocol was followed (1 mg of tissue plasminogen activator per hour per catheter after an initial 2-mg bolus per catheter). Minitab 17 (Minitab Inc, State College, PA) was used for data analysis. There were 91 patients who had a computed tomography diagnosis of acute PE and pulmonary hypertension (PAP >25 mm Hg). Seventeen patients (19%) were deemed to be at high risk for bleeding, predicted by recent hemorrhage, major surgery within 3 weeks, acute myocardial infarction, and cardiac arrest with cardiopulmonary resuscitation within 1 week. The high-risk patients in our study were noted to have higher RV:LV ratios and lower oxygen saturations on admission (P< .05). On computed tomography angiography, the mean pretherapy RVaxial:LVaxial ratio was 1.5± 0.4. The mean pretherapy PAP was 56.2± 15.2 mm Hg. After 18.5± 3.5 hours of thrombolysis, the mean post-therapy PAP was 34.3± 10.4 mm Hg, with a pressure drop of 21.9± 4.8 mm Hg (39% decrease; P< .001). In total, seven patients (8%) suffered bleeding complications that required intervention-four gastrointestinal bleeds, a rectus sheath hematoma, and one gross hematuria. Three of the seven complications occurred in the high-risk group (3/17) and the other four in the general population of patients (4/74; P= .118). Minor bleeding complications (n= 14 [15%]) did not require intervention and included puncture site hematomas, ecchymosis, and mild traumatic hematuria. Considering all bleeding complications, increasing RVaxial:LVaxial ratio was a predictor of any bleeding complication, independent of all risk factors (P= .005). CDUA thrombolysis for acute PE effectively reduced mean PAPs. Given the low incidence of major bleeding complications, even in those deemed to be clinically at high risk for bleeding, we additionally conclude that this procedure can be performed safely. Although larger studies with longer follow-up are necessary, CDUA pulmonary thrombolysis for the management of acute submassive PE appears to be effective in decreasing right-sided heart strain and can be performed with an acceptable risk profile.