Introducing the Flow Triever Mechanical Thrombectomy Device: A Nonthrombolytic Catheter-directed Approach for Intermediate to High–risk Pulmonary Embolism

Abstract

Synopsis: The FLARE (FlowTriever Pulmonary Embolectomy Clinical Study) is a prospective, single-arm, multicenter trial in which 106 patients at 18 different US sites with intermediate-risk pulmonary embolism (PE) were treated with percutaneous mechanical thrombectomy using the FlowTriever Retrieval/Aspiration System. The investigators found that the FlowTriever device met its primary effectiveness endpoint with a mean reduction in the right ventricular/left ventricular ratio at 48 hours of 0.38 (25.1%; P< 0.00010). Treated patients also had a small decrease in anatomic degree of thrombus (10% by modified Miller score), and those with pulmonary hypertension exhibited a 3.2 mmHg reduction in mean pulmonary artery pressure (P< 0.0001). There were no cases of intracranial hemorrhage, device-related cardiac or pulmonary injury, or device-related deaths. This study introduces an additional modality for the treatment of intermediate to high–risk PE. The change in right ventricular/left ventricular ratio with FlowTriever embolectomy is similar to that noted with other trials investigating catheter-directed thrombolysis and better than that of anticoagulation alone. What sets this device apart from many of its predecessors is that it does not require thrombolytics, offering a safer option to patients with absolute or relative contraindications to systemic thrombolysis. FlowTriever has shown promising results in reducing early right ventricular strain in patients with intermediate-risk PE, but its place in the algorithm in the treatment of PE will more likely be for higher risk PE, especially when relative or absolute contraindications to thrombolysis exist. The long-term benefits for patients with intermediate-risk PE will require further study. Source: Tu T, Toma C, Tapson VF, et al. A prospective, single-arm, multicenter trial of catheter-directed mechanical thrombectomy for intermediate-risk acute pulmonary embolism: the FLARE study. JACC Cardiovasc Interv. 2019:12.9:859–869.