In vitro testing of six inferior vena cava filters: filtering efficiency and pressure measurements.

UNLABELLED: The purpose of this study is to compare in standarddised ex vivo conditions the performances of six percutaneous vena cava filters available on the European Market. METHODS: We use a mock circulation with polyethylene beads simulating clots to objectively determine the filtering efficiency of the different devices. We measured pressure at contact points with the wall of the tube simulating vena cava, and also gradient of pressure induced by the empty and full filter. Statistical analysis of the data obtained (at least 100 measurements for each filter) showed great consistency in the response of a given filter to the different conditions of mock circulation. RESULTS: The Greenfield Filter, which served as the reference, was compared to the other models. Its filtering efficiency was acceptable as was that of the L.G. Filter. The Cardial Filter and Vascor Filter were the most efficient. The Antheor Filter and the Filcard Filter performed poorly. CONCLUSION: The mock circulation give reliable and reproducible data on the filtering efficiency for a device but ease of placement and clinical studies must be taken into account for the choice of the filter.