Invertible filter for embolic protection

#1. Field of the Invention

#The present invention generally relates to a medical device for embolic protection.

#2. Description of Related Art

#FIG. 1 is a partial sectional view of a medical device in accordance with the present invention;

#FIG. 2 is a sectional view of a blood vessel including a stenosis and illustrating the introduction of the medical device of FIG. 1, in accordance with the present invention;

#FIG. 3 is a sectional view of the blood vessel illustrating deployment of the medical device in FIG. 1;

#Referring now to FIG. 1, a medical device embodying the principles of the present invention is denoted by reference numeral 10. The medical device 10 includes a flexible filter portion 12 and a guiding member 16. The filter portion 12 extends distally from the guiding member 16.

#In the embodiment shown, the filter portion 12 is made from a mesh material. The mesh material has a tubular geometry including a first opening at the first end 13 of the filter portion 12 and a second opening at the second end of the filter portion 12. The first end 13 extends distally from the guiding member 16 and the second end is engaged by a lumen formed in the guiding member 16. The mesh material includes a plurality of interwoven elements 19. The elements 19 are interwoven such that the diameter of the filter portion 12 can expand or contract while maintaining its generally tubular geometry. To facilitate deployment of the medical device 10, the filter portion 12 may be biased to expand. However, when contracted, the tubular geometry provides a very small profile during insertion of the medical device and facilitates passing the medical device 10 through the stenosis.

#The elements 19 may be comprised of any suitable material such as a superelastic material, stainless steel wire, cobalt-chromium-nickel-molybdenum-iron alloy, or cobalt-chrome alloy. Alternatively, the elements 19 may be formed of a synthetic material. For example, Nylon, Dacron, Thorolon, or ePTFE may be used. Depending on the application, the mesh material may include multiple layers or a composite mesh of elements 19, such as a nano fiber mesh. In addition, the elements 19 may include an agent bonded thereto for release in the vessel, such as an anticoagulant. Further, it is understood that the elements 19 may be formed of any other suitable material that will result in a flexible everting geometry, such as shape memory alloys. The mesh material includes openings 18 between the strands that are large enough to allow the flow of blood therethrough, but small enough to capture emboli. Accordingly, the weave of the elements 19 may be configured such that the openings 18 between the strands are between about 30 and 100 microns, although other size openings may be used. Openings of this size in the filter portion 12 will allow blood cells to pass through the openings 18 while larger emboli are constrained by the elements 19.