Intraluminal filter

• US 6,375,670 B1
• Filed: 08/25/2000
• Issued: 04/23/2002
• Est. Priority Date: 10/07/1999
• Status: Expired due to Fees

• Current Assignee: Prodesco, Inc. (Compagnie Generale DES Etablissements Michelin SCA)
• Original Assignee: Prodesco, Inc. (Compagnie Generale DES Etablissements Michelin SCA)
• Inventors: Greenhalgh, E. Skott
• Primary Examiner(s): Truong, Kevin
• Application Number:
  US09/645,842
• Time in Patent Office: 606 Days
• Field of Search: 606/200, 606/127, 606/159, 606/113, 606/114, 606/128
• US Class Current: 606/200
• CPC Class Codes: A61F 2/01 Filters implantable into blood vessels
• CPC Class Codes: A61F 2/0108 Both ends closed, i.e. legs gathered at both ends
• CPC Class Codes: A61F 2/011 Instruments for their placement or removal
• CPC Class Codes: A61F 2002/015 Stop means therefor
• CPC Class Codes: A61F 2002/018 made from tubes or sheets of material, e.g. by etching or laser-cutting
• CPC Class Codes: A61F 2230/0006 circular
• CPC Class Codes: A61F 2230/008 paraboloidal

Abstract

An intraluminal filter for vascular use during medical procedures is disclosed. The filter is formed of a plurality of flexible, resilient monofilament wires interbraided in a relatively open mesh forming a basket with a plurality of multifilament yarns braided in a relatively closed mesh having a predetermined porosity forming a filter element. The filter element is positioned distally of the basket forming a concave portion, the remaining portion of the basket being unobstructed and forming openings facing the concave portion. The filter is elastically deformable between two shape states, the first having a small diameter enabling the filter to slide within the bore of a catheter for positioning the filter in the lumen of an artery, the second shape state having a substantially larger diameter sized to sealingly interfit within the artery lumen. The filter is biased and will expand upon release from the catheter to the second shape state. The open portion is positioned upstream allowing blood to flow into the concave portion of the filter element, particles above a certain size being captured in the filter while blood is allowed to flow through. A tether is attached to the upstream end of the filter allowing it to be withdrawn into the catheter bore for removing the filter from the artery.

Claims

1. An intraluminal filter positionable within a lumen for separating entrained particles from a fluid flowing within said lumen, said intraluminal filter comprising a plurality of filamentary members interlaced to form a basket having an upstream portion and a concave portion arranged to face said upstream portion, said upstream portion having openings sized to allow said fluid and said entrained particles to flow through and into said concave portion when said upstream portion is oriented upstream within said lumen, said concave portion comprising a filter element having openings of predetermined size smaller than the first named openings, the openings of said concave portion being sized to capture said entrained particles while allowing said fluid to flow therethrough, said intraluminal filter further comprising a means for biasing said basket from a first shape state having a first diameter sized to allow said basket to slidingly fit within the bore of a catheter positionable within said lumen, to a biased second shape state having a second diameter substantially larger than said first diameter, said biasing means biasing said basket into said second shape state upon release of said basket from said bore, said biased second shape state being sized to allow said basket to sealingly interfit within said lumen.

2. An intraluminal filter according to claim 1, wherein said biasing means comprises selected ones of said filamentary members, said selected ones of said filamentary members being resilient and biased by internal elastic forces to expand said basket into said biased second shape state when said basket is released from said catheter.

3. An intraluminal filter according to claim 1, wherein said biasing means comprises a plurality of supplemental filamentary members, said supplemental filamentary members being elastic and oriented to compress said basket into said biased second shape state, said supplemental filamentary members being under tension when said basket is in said first shape state and compressing said basket to bias it into said second shape state upon release of said basket from said catheter.

4. An intraluminal filter according to claim 3, wherein said filamentary members are interlaced by braiding and said supplemental filamentary members are interbraided with said filamentary members.

5. An intraluminal filter according to claim 1, wherein said basket comprises a support structure formed of a plurality of first filamentary members and said filter element comprises a plurality of second filamentary members interlaced with one another and said first filamentary members.

6. An intraluminal filter according to claim 5, wherein at least some of said first filamentary members are resilient and biased by internal elastic forces to expand said basket into said biased second shape state when said basket is released from said catheter.

7. An intraluminal filter according to claim 5, further comprising a flexible tether attached to said upstream portion of said basket, said tether having a predetermined length and being extendable through said catheter for allowing said filter to be manually withdrawn from said lumen into said catheter bore.

8. An intraluminal filter according to claim 5, wherein said first and second filamentary members are braided into a tube having a predetermined length, said tube having oppositely arranged ends gathered and cinched to form said upstream and concave portions.

9. An intraluminal filter according to claim 8, wherein said second filamentary members comprise a thermoplastic polymer.

10. An intraluminal filter according to claim 9, wherein said second filamentary members are heat fused to said first filamentary members.

11. An intraluminal filter according to claim 1, further comprising a plurality of projections extending outwardly from said filter and interengaging an internal surface of said lumen for fixing said filter at a predetermined location therein.

12. An intraluminal filter according to claim 11, wherein said projections comprise a plurality of said filamentary members each having an end extending angularly outwardly from said basket and facing downstream to engage said lumen internal surface.

13. An intraluminal filter according to claim 12, wherein said projections extend outwardly from said upstream portion.

14. An intraluminal filter according to claim 1, wherein said biasing means comprises an elongated elastic member having one end attached to said upstream portion and the other end attached to said concave portion, said elastic member being under tension when said basket is in said first shape state and biasing said upstream portion toward said downstream portion to expand said basket from said first to said second shape state.

15. An intraluminal filter according to claim 14, wherein said elongated elastic member comprises a coil spring.

16. An intraluminal filter according to claim 1 coaxially mountable on an elongated guide wire, a stopper being positioned on the guide wire at a point along its length, said guide wire being positionable within said lumen, said filter further comprising:

a first aperture located in said upstream portion for receiving said guide wire therethrough;

a second aperture located in said concave portion for receiving said guide wire therethrough;

one of said portions having a surface positioned at one of said apertures to engage said stopper and prevent motion of said filter relative to said guide wire; and

a means for sealing said second aperture.

17. An intraluminal filter according to claim 16, wherein said surface is positioned at said first aperture.

18. An intraluminal filter according to claim 16, wherein said sealing means comprises an elongated tube positioned within said basket and coaxially connecting said first and second apertures in sealing relationship, said tube coaxially receiving said guide wire.

19. An intraluminal filter according to claim 16, wherein said sealing means comprises a check valve positioned in said second aperture, said check valve having a flexible flap movable upon interengagement with said stopper from a closed position sealing said second aperture, to an open position allowing said stopper to pass through said second aperture into said filter.

20. An intraluminal filter for trapping and retaining particles entrained in a fluid flowing within a lumen, said filter comprising:

an elastically deformable basket formed of a plurality of flexible, resilient filamentary members interlaced in a relatively open mesh, the mesh being comprised of openings of a size allowing flow of said fluid and said entrained particles therethrough, said basket being elastically radially compressible to a first shape state having a first predetermined diameter sized to slidingly interfit within a catheter positionable within said lumen, and being radially expandible to a second shape state having a second predetermined diameter larger than the first to sealingly interfit within said lumen, said basket being biased by elastic forces of said filamentary members to nominally assume said second shape state, and being elastically and repeatably deformable between said shape states;

said basket having a relatively open first portion and filter means disposed opposite to said first portion, said filter means having a concave surface of predetermined porosity facing said first portion for capturing said entrained particles when said basket is in said second shape state and positioned in said lumen with said first portion arranged upstream of said filter means.

21. An intraluminal filter according to claim 20, wherein said filamentary members are monofilament wires.

22. An intraluminal filter according to claim 21, wherein said filamentary members are interlaced by braiding.

23. An intraluminal filter according to claim 22, wherein said filter means comprises a multiplicity of multifilament yarns braided with one another and with said filamentary members in a relatively closed mesh.

24. An intraluminal filter according to claim 23, wherein said yarns consist essentially of polyester.

25. An intraluminal filter according to claim 21, wherein said filamentary members comprise a radiopaque material.

26. An intraluminal filter according to claim 25, wherein said radiopaque material is nitinol.

27. An intraluminal filter according to claim 20, wherein said lumen is a vascular lumen.

28. An intraluminal filter according to claim 20, wherein the porosity of said filter means ranges between about 60% and 90%.

29. An intraluminal filter according to claim 20, further comprising a plurality of projecting members having end portions projecting angularly outwardly from said filter and being interengagable with said lumen for preventing downstream movement of the filter, said end portions pointing in the downstream direction to allow said end portions to readily disengage from said lumen when said filter is moved in an upstream direction for retraction of the filter into the catheter.

30. An intraluminal filter according to claim 29, wherein said projecting members are monofilament wires being selected ones of said resilient filamentary members comprising said basket, said projecting members being present in the ration of about one to one with said resilient filamentary members.

31. A method of forming an intraluminal filter comprising the steps of:

providing a plurality of first filamentary members, said first filamentary members being flexible and resilient;

braiding said plurality of first filamentary members into a relatively open mesh forming an elastically deformable tube;

interbraiding a plurality of second filamentary members with said first filamentary members to form a surface having a predetermined porosity;

biasing said first filamentary members to urge said tube to assume a predetermined length and diameter;

gathering each end of said tube and cinching each said end together to form an elastically deformable basket;

removing said second filamentary members from a portion of said basket at one end of said tube thereby forming openings at said one end; and

attaching said second filamentary members to said first filamentary members adjacent to said portion of said basket.

32. A method of forming an intraluminal filter according to claim 31, wherein said second filamentary are formed of a polymer, said polymer having a lower melting point than said first filamentary members and said removing step is performed by ablating said second filamentary members.

33. A method of forming an intraluminal filter according to claim 32, wherein said attaching step is performed by heat sealing said second filamentary members to said first filamentary members.