Intraluminal filter

• US 6,364,895 B1
• Filed: 01/28/2000
• Issued: 04/02/2002
• 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 THAO
• Application Number:
  US09/494,323
• Time in Patent Office: 795 Days
• Field of Search: 606/200, 606/127, 606/159, 606/113, 606/114, 606/128, 606/108
• US Class Current: 606/200
• 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 A tether is attached to the upstream end of the filter allowing it to be withdrawn into the catheter bore for removing the filter from the artery.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 positionble within a lumen for separating particles from a fluid flowing within said lumen, said intraluminal filter comprising:

a first plurality of filamentary members formed of a flexible, resilient material and interlaced in a relatively open mesh to form a basket, said first filamentary members elastically deforming 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 second shape state having a second diameter substantially larger than said first diameter and sized to allow said basket to sealingly interfit within said lumen, said basket being biased by internal elastic forces within said first filamentary members to assume said second shape state when released from said catheter;

a second plurality of filamentary members interlaced with one another and with said first filamentary members to form a concave first portion of said basket, said basket having a second portion remaining unobstructed and arranged facing said concave first portion, said relatively open mesh having openings sized to allow said fluid and said particles to flow through said second portion into said concave first portion when said second portion is oriented upstream within said lumen, said concave first portion comprising a filter element having second openings of predetermined size smaller than the first named openings, said second openings being sized to capture entrained particles while allowing said fluid to flow therethrough.

2. An intraluminal filter according to claim 1, wherein said first filamentary members are braided into a tube having a predetermined length, said tube having oppositely arranged ends gathered and cinched to form said basket, one of said ends forming said second portion of said basket and being unobstructed to form said first openings.

3. An intraluminal filter according to claim 2, further comprising a flexible tether attached to said one end 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.

4. An intraluminal filter according to claim 1, wherein said second filamentary members comprise a thermoplastic polymer.

5. An intraluminal filter according to claim 4, wherein said second filamentary members are heat sealed to said first filamentary members adjacent to said second portion of said basket.

6. 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.

7. An intraluminal filter according to claim 6, wherein said projections comprise a third plurality of filamentary members interlaced with said first plurality, said filamentary members of said third plurality each having an end located adjacent to said first portion of said basket, each said end extending angularly outwardly of the filter and facing downstream to engage said lumen internal surface.

8. An intraluminal filter according to claim 7, wherein each said end is formed by cutting said filaments of said third plurality, said ends adjacent to said first portion of said basket being relatively unrestrained by said first plurality of filamentary members to allow said ends to project angularly outwardly, end portions at said second portion of said basket being restrained by said filter element.

9. 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 of a size allowing flow of said fluid and said 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 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.

10. An intraluminal filter according to claim 9, wherein said filamentary members are monofilament wires.

11. An intraluminal filter according to claim 10, wherein said filamentary members are interlaced by braiding.

12. An intraluminal filter according to claim 11, wherein said filter means comprises a multiplicity of multifilament yarns braided with one another and with said filamentary members in a relatively closed mesh.

13. An intraluminal filter according to claim 12, wherein said yarns consist essentially of polyester.

14. An intraluminal filter according to claim 10, wherein said filamentary members comprise a radiopaque material.

15. An intraluminal filter according to claim 14, wherein said radiopaque material is nitinol.

16. An intraluminal filter according to claim 9, further comprising a flexible tether attached to said basket on said second portion, said tether being elongated and extendable through said catheter for manually drawing said basket into said catheter.

17. An intraluminal filter according to claim 9, wherein said lumen is a vascular lumen.

18. An intraluminal filter according to claim 9, wherein the porosity of said filter means ranges between about 60% and 90%.

19. An intraluminal filter according to claim 9, 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.

20. An intraluminal filter according to claim 19, 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.

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

braiding a plurality of flexible, resilient filamentary members into a relatively open mesh forming an elastically deformable tube, said filamentary members providing a radial bias to said tube, urging said tube to assume a predetermined length and diameter;

interbraiding a multiplicity of yarns with said first filamentary members to form with said filamentary members a surface having a predetermined porosity;

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

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

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

22. A method of forming an intraluminal filter according to claim 21, wherein said yarns are formed of a polymer, said polymer having a lower melting point than said flexible, resilient filamentary members and said removing step is performed by ablating said yarns.

23. A method of forming an intraluminal filter according to claim 22, wherein said attaching step is performed by heat sealing said yarns to said filamentary members.