Clover leaf inferior vena cava filter: in vitro evaluation of filter deployment and comparison of emboli-capturing ability.

A new self-centering stainless steel inferior vena cava filter (clover leaf filter) that can be delivered percutaneously through a 10-F catheter has been developed. The filter is loaded into an angiographic catheter as a set of straightened wires that are mechanically deformed into a predetermined clover leaf shape when the device is delivered. The filter can be deployed easily and effectively into the simulated vena cava. Emboli-capturing efficiency of the new filter was compared in vitro to that of the Greenfield and Bird's Nest inferior vena cava filters. All three filters captured all large 5 x 100-mm, potentially fatal emboli. The clover leaf filter captures more of the smaller (5 x 20-mm and 3 x 20-mm) emboli than the Greenfield filter and less than the Bird's Nest filter.