The 6-F nitinol TrapEase inferior vena cava filter: Results of a prospective multicenter trial

PURPOSE: The authors report the first results of a new 6-F symmetrically de signed permanent nitinol inferior vena cava (IVC) filter, the Cordis TrapEa se, evaluated in a multicenter prospective study with 6-months of follow-up . MATERIALS AND METHODS: A total of 65 patients (29 men, 36 women) who ranged in age from 37 to 96 years (mean age, 68 years) and who were at high risk of pulmonary embolism (PE) were enrolled in 12 centers in Europe and Canada . The study was approved by the institutional review boards at all centers. Study objectives were to evaluate filter effectiveness, filter stability, and caval occlusion. Indications for filter placement were deep vein thromb osis with recurrent thromboembolism and/or free-floating thrombus with cont raindication to anticoagulation in 37 patients, and complications in achiev ing adequate anticoagulation in 28 patients. Follow-up included clinical ex amination, plain film, Doppler ultrasound, CT scan, and nuclear medicine. RESULTS: The analysis of the data revealed a technical success of 95.4% (th ree filter-system related implantations not at the intended site, no events of filter tilting) and a clinical success of 100% at 6 months (no cases of symptomatic PE), the study primary endpoint. There were no cases (0%) of f ilter migration, insertion site thrombosis, filter fracture, or vessel wall perforation. During the study period, there were two cases of filter throm bosis: one case of early symptomatic thrombosis that was successfully treat ed in the hospital, and one case of nonsymptomatic filter thrombosis detect ed at 1-month follow-up, with spontaneous recanalization at 3 months. In th e latter patient, some residual thrombus was still detected at 6 months. Of the study population of 65 patients, there were 23 deaths. These deaths we re not related-to the device or the implantation procedure but to the under lying disease process. CONCLUSION: This study demonstrates the new nitinol permanent IVC filter to be a safe and an effective device, with a low overall complication rate, f or use in patients with thromboembolic disease at high risk of PE.