In vivo assessment of a new long-term filtration device for embolic stroke prevention

Based on in vitro optimization, a new filtering implant (the Diverter) was designed to divert emboli away from the internal into the external carotid artery to prevent embolic stroke from proximal sources. Our aim was to test the patency of the permanent arterial filter crossing arterial bifurcations of swine. Biocompatible Diverters (29), composed of multiple fine wire meshes, were implanted in illio-femoral bifurcations of 45kg swine for up to 18 weeks. The bifurcations were harvested and patency percentage of the filtered ostium was computed using image morphometry. Angiography and Duplex prior to animal sacrifice found the Diverter open to flow without occlusion or discernable stenosis up to 18 weeks post implantation in all devices except 3 mechanical failures. The Diverters were fully covered at the non-filtering portion area after 4 weeks. Morphometry showed that 90% (average) of filtered area of the 26 specimens remained patent, (93, 92, 72 and 93 [%] at 2, 4, 9, and 18 weeks respectively). Implantation of a permanent arterial filtration device is feasible and such a device remains patent. Our preliminary findings give hope to a new therapy for patients at high risk of embolic stroke.