ABSTRACT
OBJECTIVE: Chronically indwelling inferior vena cava filters (IVCFs) can have multiple adverse sequelae, including IVCF-associated thrombosis. The Inari ClotTriever and FlowTriever mechanical and aspiration thrombectomy systems (Inari Medical) can be used for acute caval thrombosis associated with IVCFs if appropriate proximal IVCF protection is used intraprocedurally. The present study reports a single institution's outcomes after ClotTriever and FlowTriever thrombectomy of acute IVCF-associated iliocaval thrombus. METHODS: A retrospective review was conducted of all patients who underwent ClotTriever or FlowTriever thrombectomy for IVCF-associated caval thrombosis. The patient demographics, clinical characteristics, and postprocedural outcomes of a 15-patient cohort were compiled and described. RESULTS: A total of 15 patients were identified as presenting with acute IVCF-associated caval thrombosis and having undergone intervention with either the ClotTriever or FlowTriever system from 2019 to 2022. Of the 15 patients in the cohort, 3 (20%) had presented with a threatened extremity (phlegmasia cerulea dolens), and 12 had presented with severe, debilitating, but non-limb-threatening, lower extremity edema. The preprocedural clot burden was significant and involved the cava, iliac veins, and femoropopliteal veins in 7 of 15 patients (47%) in the cohort. The procedure was technically successful in 11 patients (73.33%). Resolution of acute symptoms was noted in 100% of the technically successful procedures. The 30-day mortality rate was 13% (2 of 15 patients). One intraprocedural death occurred from pulmonary embolism, and one patient died of malignancy complications. The surviving patients not lost to follow-up experienced stable or improving venous disease, with only one patient presenting with post-phlebitic syndrome. CONCLUSIONS: Mechanical and aspiration thrombectomy of IVCF-associated thrombus with the FlowTriever and ClotTriever systems have good technical success and resulted in significant improvement in acute symptoms with adequate clot clearance. Proximal embolic protection maneuvers for pulmonary embolism prophylaxis and preexisting filter protection are required intraprocedurally.
