Safety and Clinical Outcomes of the Inari FlowTriever device for aspiration thrombectomy in patients with acute submassive and massive pulmonary embolism: a single-arm, retrospective review

Our study seeks to evaluate the safety of percutaneous suction thrombectomy using the Inari FlowTriever System for treatment of both massive and submassive acute pulmonary embolism (PE).


Materials and Methods:

This IRB-approved single-arm retrospective review was performed on patients who underwent FlowTriever thrombectomy from Jan 2015 to Dec 2021. An internal database was queried for PE thrombectomy procedures, and electronic health records were reviewed for periprocedural clinical values, procedural reports and images, and follow up data. Primary outcomes were 30-day and 1-year mortality, procedure-related complications, and technical success defined as sufficient removal of thrombus without repeat intervention or adjunctive lytic therapy within 30 days.



Results:

101 patients with massive (n=48) or submassive (n=53) PE were treated with FlowTriever aspiration thrombectomy. 10 patients with massive PE received systemic thrombolytics prior to presentation and 1 patient with submassive PE received a partial dose. Technical success was achieved in 86% of cases. The overall complication rate was 15%, varying between massive (13/48, 27%) and submassive (2/53, 4%) groups. Complications in massive PE cases included 1 occurrence of insufficient clot retrieval, 8 episodes of hemodynamic instability requiring later reintervention (n = 2) or resuscitation/ECMO (n = 6), 3 episodes of hemorrhage, and one patient which required 4 mg of additional catheter-based lytic therapy. Complications among submassive PE patients included insufficient clot retrieval (n=1) and self-resolved hemodynamic instability (n=1). PE recurrence was 4%. 30-day mortality for massive PE was 27%, and 0% for submassive PE. One-year mortality was 38.8% (n=19) for massive PE and 13.2% (n=7) for submassive PE. Patients with prior systemic lytics had elevated complication (50%) and mortality (40% at 30-days, 50% at 1 year) rates compared to the overall group.



Conclusion: This single-center review reports high technical success without adjunctive therapy. For massive PE, mortality rates were similar to prior published results and complication rates were low, supporting use of large-bore suction thrombectomy in patients with contraindications to systemic lytics. Prior lytic therapy may increase risk of complication and mortality, although further studies are needed. For submassive PE, both 30-day mortality rates and severe adverse event rates were 0%, suggesting large-bore suction thrombectomy could provide a safe and effective first-line treatment.