A Safety and Feasibility Single-Arm Study of a Novel Catheter Thrombectomy Device for the Treatment of Pulmonary Embolism (ENGULF)

Background: Despite advances in therapy options, pulmonary embolism (PE) continues to carry a high risk of mortality and morbidity. Currently, therapeutic options are limited with only 2 US Food and Drug Administration-cleared catheter-based embolectomy devices approved for the treatment of intermediate-risk PE. The novel Hēlo PE thrombectomy catheter (Endovascular Engineering, Inc) has a flexible and collapsible funnel with an internal agitator for a dual mechanism of treatment for acute PE. We sought to investigate the safety and feasibility of the novel Hēlo PE thrombectomy catheter in intermediate-risk PE.

Methods: A prospective, single-arm feasibility study evaluating the Hēlo PE catheter was performed in patients presenting with intermediate-risk PE. Patients underwent preprocedural and postprocedural computed tomography angiography. Primary efficacy was the difference in preprocedural to postprocedural right ventricle/left ventricle (RV/LV) ratio. Primary and secondary safety outcomes were all-cause mortality, major life-threatening bleeding, device-related serious adverse events, pulmonary or cardiac injury, and clinical decompensation at 48 hours postprocedure and at 30 days.

Results: A total of 25 patients from 8 centers were consented and included in the analysis. Preprocedural computed tomography angiography revealed an RV/LV ratio of 1.53 ± 0.27. All patients underwent a successful thrombectomy procedure. Postprocedure, the RV/LV ratio was reduced to 1.15 ± 0.18, translating into a 23.2 ± 12.81% decrease from baseline. No patients underwent adjunctive thrombolysis. Two patients had adjunctive catheter-directed embolectomy with an alternative device. Two patients had postprocedural anemia requiring transfusion but did not meet criteria for major life-threatening bleeding by VARC-2 criteria. There were no major adverse events including no deaths, major bleeding, pulmonary injury, or vascular complications at 48 hours or 30 days post procedure.

Conclusions: In this multicenter first-in-human study, use of the Hēlo PE thrombectomy catheter was feasible and safe for the treatment of acute PE.