Vena cava filter

• US 6,126,673 A
• Filed: 11/17/1998
• Issued: 10/03/2000
• Est. Priority Date: 10/01/1993
• Status: Expired due to Term

• Current Assignee: Lifescreen Sciences LLC (Acacia Research Corporation)
• Original Assignee: Boston Scientific Corporation
• Inventors: Kim, Hannah S., Sandock, David L., Nott, Sepideh H.
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): LEWIS, WILLIAM W
• Application Number:
  US09/195,182
• Time in Patent Office: 686 Days
• Field of Search: 606/1, 606/108, 606/191, 606/194, 606/195, 606/198, 606/200, 623/1, 623/12
• US Class Current: 606/200
• CPC Class Codes: A61F 2/0103 With centering means
• CPC Class Codes: A61F 2/0105 Open ended, i.e. legs gathered only at one side
• CPC Class Codes: A61F 2002/016 made from wire-like elements
• CPC Class Codes: A61F 2002/018 made from tubes or sheets of material, e.g. by etching or laser-cutting
• CPC Class Codes: A61F 2002/8483 Barbs
• CPC Class Codes: A61F 2230/005 Rosette-shaped, e.g. star-shaped
• CPC Class Codes: A61F 2230/0067 conical
• CPC Class Codes: A61F 2230/0078 hyperboloidal
• CPC Class Codes: A61F 2230/008 paraboloidal

Abstract

A vascular filter-comprises an emboli-capturing portion having a set of helical filter-wires joined at a central region and extending in a given direction along the blood vessel in a diverging relationship to the axis of the filter, the wires terminating in free ends constructed to engage the walls of said vessel. A major mid-portion of the length of the free ended wires are of generally helical form, cooperatively related to form an effective emboli capturing array. Anchoring is accomplished by a separate assembly formed of struts and anchoring devices. A parallelogram supporting strut assembly and other members for providing linear engagement with the wall of the vena cava are shown. The parallelogram structure is shown to have filter capability by itself as well.

Claims

1. A vascular filter for placement in a blood vessel for preventing the movement of emboli in the blood stream of a human, the filter comprising:

a set of filter-wires that diverge from a central joining region forming an emoboli-capturing array, the filter-wires having portions that engage the vessel wall; and

an anchoring assembly defined by at least one set of struts joined centrally with said set of filter-wires, wall engaging portions of said anchoring assembly constructed and arranged to engage the wall of said blood vessel in a manner anchoring said filter in position, the region of said anchoring being spaced from the region of contact of said set of filter wires with said vessel wall, wherein the struts extend from said central joining region a distance that is shorter than the distance said filter-wires extend from the central joining region, and diverge at a greater angle relative to the longitudinal axis of the filter than said filter-wires, the spacing of the regions of contact of said filter-wires and said struts with the vascular wall being selected to stabilize said filter in said vessel in a generally centered relationship.

2. The filter of claim 1, wherein said regions of contact of said set of filter-wires and of said set of struts are circumferentially offset from each other.

3. The filter of claim 1, wherein said struts diverge from said central joining region in the same general direction as said filter-wires diverge from said central joining region.

4. The filter of claim 1, wherein said struts diverge from said central joining region in a direction opposite the direction said filter-wires diverge from said central joining region.

5. The filter of claim 1, wherein said regions of contact of said filter-wires are upstream with respect to a direction of blood flow from said regions of contact of said struts.

6. The filter of claim 1, wherein said filter-wires have a continuous curvature when implanted.

7. The filter of claim 6, wherein said curvature of said filter-wires is generally concave facing the longitudinal axis.

8. The filter of claim 6, wherein said curvature of said filter-wires includes a generally helical mid-portion.

9. The filter of claim 1, wherein said struts have a continuous curvature when implanted.

10. The filter of claim 9, wherein said curvature of said struts is generally concave facing the longitudinal axis.

11. The filter of claim 10, wherein said filter-wires have a continuous curvature when implanted that is generally concave facing the longitudinal axis.

26. The filter of claim 1, wherein said wall-engaging portions comprise linear elements constructed and arranged to maintain generally linear contact with the vessel walls, said linear elements each supported in its mid-region by a strut of said set.

12. A vascular filter for placement in a blood vessel for preventing the movement of emboli in the blood stream of a human, the filter comprising:

an emboli-capturing portion having a set of filter-wires that diverge from a central joining region in a given direction along the blood vessel, the filter-wires terminating in free ends constructed to contact the wall of said vessel, wherein at least a portion of said filter-wires are of generally concave curved form with respect to a longitudinal axis of said filter and conform generally to an imaginary cone, and wherein said filter-wires are cooperatively related to form an effective emboli-capturing array.

13. The filter of claim 12, further comprising an anchoring assembly defined by least one set of struts diverging from said central joining region, portions of said anchoring assembly constructed to engage the wall of said blood vessel in a manner anchoring said filter in position, wherein the region of said anchoring is spaced from the region of contact of said filter-wires with said vessel wall.

14. The filter of claim 13, wherein the region of anchoring is upstream from the region of contact of said filter-wires with respect to a direction of blood flow in the vessel.

15. The filter of claim 13, wherein said struts extend from said central joining region a distance that is shorter than the distance said filter-wires extend from the central joining region, and diverge at a greater angle relative to the longitudinal axis of the filter than said filter-wires.

16. The filter of claim 13, wherein a mid-portion of said struts have a continuous curvature when implanted, wherein said curvature of said struts is generally concave with respect to a longitudinal axis of said filter.

17. The filter of claim 13, wherein said struts diverge from said central joining region in the same general direction as said filter-wires diverge from said central joining region.

18. The filter of claim 13, wherein said struts diverge from said central joining region in a direction opposite the direction said filter-wires diverge from said central joining region.

19. The filter of claim 12, wherein said mid-portion of said free ended filter-wires further have a helical curvature.

20. A vascular filter for placement in a blood vessel for preventing the movement of emboli in the blood stream of a human, the filter comprising:

an emboli-capturing portion having a set of filter-wires that diverge from a central joining region in a given direction along the blood vessel, the filter-wires terminating in free ends constructed to contact the wall of said vessel, wherein at least a mid-portion of said filter-wires are of generally curved form and conform generally to an imaginary cone, and wherein said filter-wires are cooperatively related to form an effective emboli-capturing array; and

an anchoring assembly defined by at least one set of struts diverging from said central joining region, said anchoring assembly constructed to engage the wall of said blood vessel in a manner anchoring said filter in position, wherein the region of said anchoring is spaced upstream from the region of contact of said filter-wires with said vessel wall with respect to a direction of blood flow in the vessel.

21. The filter of claim 20, wherein a mid-portion of said struts have a continuous curvature when implanted.

22. The filter of claim 21, wherein said cuvature of said struts is generally concave with respect to a longitudinal axis of said filter.

23. A vascular filter for placement in a blood vessel for preventing the movement of emboli in the blood stream of a human, the filter comprising:

a set of filter-wires that diverge from a central region in a given direction along the blood vessel forming an emboli-capturing array, the filter-wires having portions that engage the vessel wall; and

an anchoring assembly defined by at least one set of struts diverging from said central region in a direction opposite to the direction of divergence of said set of filter wires, the region of said anchoring being spaced from the region of contact of said set of filter-wires with said vessel wall, wherein said struts terminate in portions that engage the wall of said blood vessel in a manner anchoring said filter in position, the spacing of the regions of contact of said sets of filter-wires and said struts with the vascular wall being selected to stabilize said filter in said vessel in a generally centered relationship.

24. The filter of claim 23, wherein wall-engaging formations supported by said struts are constructed and arranged to maintain generally linear contact with the vessel walls.

25. The filter of claim 24, wherein said wall-engaging formations are linear elements each supported in its mid-region by a strut of said set.

27. A vascular filter for placement in a blood vessel for preventing the movement of emboli in the blood stream of a human, the filter comprising:

a set of filter-wires that diverge from a central region in a given direction along the blood vessel forming an emboli-capturing array, the filter wires having portions that engage the vessel wall; and

an anchoring assembly defined by at least one set of struts joined centrally with said set of filter-wires, portions of said anchoring assembly contructed and arranged to engage the wall of said blood vessel in a manner anchoring said filter in position, the region of said anchoring being spaced from the region of contact of said set of filter-wires with said vessel wall, wherein said struts have free end portions constructed to engage the wall of said vessel, there being a plurality of anchoring formations on said strut, said formations arranged so that one said formation is relatively more effective for anchoring in walls of blood vessels of relatively large size and the other formation is relatively more effective for anchoring in walls of smaller size vessels.

28. The filter of claim 27, wherein each said anchoring formation comprises at least one pointed projection.

29. The filter of claim 27, wherein each said anchoring formation comprises at least one pair of pointed projections, the projections of said pair being oriented in opposite directions along the blood vessel, each being angled to penetrate into wall tissue, said pair of projections being effective to resist dislodgement of said strut in either direction along said vessel.