Use of a temporary caval filter to assist percutaneous iliocaval thrombectomy: experimental results

To test a new filter design that allows coaxial insertion of thrombectomy devices and active clot removal.

A prototype filter system was used in animal experiments. It is a transjugularly inserted coaxial system with a 16-F outer sheath and an inner tube that is covered by a tulip-shaped meshwork with a 22-mm diameter at its inserted end. The inner tube allows insertion of instruments up to 8 F. The filter was developed to assist with percutaneous mechanical thrombectomy in the iliofemoral and caval veins. The filter has been used as an assisting tool in nine sheep and eight pigs. It was combined with an impeller system in nine sheep for caval thrombectomy and with a hydrodynamic catheter for iliac thrombectomy in eight pigs after artificial induction of iliac or caval thrombosis.

The filters captured emboli from the intervention in six of nine sheep. The amount of captured emboli was reduced within the filter cone by the impeller instrument in five of six instances. Residual thrombus was removed by closing the filter in five of six sheep. In pigs, the filter captured emboli in three cases during hydrodynamic embolectomy. Pulmonary embolization did not occur with the filter in place. After filter removal, minor pulmonary clot embolization occurred in one case.

The temporary tulip filter was effective in these animal models in capturing and removing thrombus material that may dislodge from iliocaval veins during mechanical thrombectomy.