Multicenter investigation for vena caval filter fractures

Vena caval filters are well used to prevent fatal pulmonary thromboembolism. However, the mid to long-term efficacy is not yet established because filters increase the risk of recurrent deep vein thrombosis. Moreover, filter fractures may cause severe complications leading to death including cardiac tamponade although the actual prevalence is not reported enough. Thus, we investigated the filter fractures retrospectively in several hospitals. Based on the database in 8 hospitals, filter fractures were investigated using plain X-ray or CT. The fracture prevalence of each filter brand, the position of filters (suprarenal; SR vs. infrarenal; IR), and the follow up durations were documented. 294 (SR46, IR 248) Gunther Tulip (GT), 138 (SR39, IR99) Trap/OptEase (TOE), 38ALN (SR0, IR38) and 2 (SR0, IR2) VenaTech (VT) were implanted in 472 consecutive patients (62.5 ± 15.4, 20-94y/o、M200, F272). 3 (1.02%) GT (SR0, IR3), 18 (13.04%) TOE (SR7, IR11) revealed filter fractures, while the others did not. TOE showed significantly higher rates of fractures than GT (p＜0.01). The periods until the discovery of TOE fractures (1340.2 ± 1008.9, 69-3775) were shorter than the ones of GT (2,365.0 ± 1929.6, 895-4,550 days) without significant difference. Any significant difference was identified depending on the filter positions (SR8.2% vs. IR4.0%). TOF is not suitable for permanent implantation due to relatively early and high fracture rates.