Non-entangling vena cava filter

• US 20060030875A1
• Filed: 08/04/2004
• Published: 02/09/2006
• Est. Priority Date: 08/04/2004
• Status: Active Grant

• Current Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Tessmer, Alexander W.
• Granted Patent: US 7,704,267 B2
• Time in Patent Office: Days
• US Class Current: 606/200
• 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 2220/0016 with sharp anchoring protrusions, e.g. barbs, pins, spikes
• CPC Class Codes: A61F 2230/005 Rosette-shaped, e.g. star-shaped
• CPC Class Codes: A61F 2230/0067 conical
• CPC Class Codes: A61F 2230/008 paraboloidal
• CPC Class Codes: A61F 2230/0093 Umbrella-shaped, e.g. mushroom-shaped

Abstract

An implantable vessel filter device having a plurality of radially expandable legs with hooks, and a center-post configured to prevent entanglement of the radially expandable legs when they are compressed against the center-post. In one variation, the filter device comprises a first set of legs, forming a first filter basket in the expanded position, and a second set of legs, forming a second filter basket distal to the first filter in the expanded position. Hooks may be provided on the second set of legs to prevent migration of the filter along the vessel after the filter is deployed. Grooves may be provided along the shaft of the center-post to receive the hooks and prevent the hooks from interlocking when the legs of the filter are compressed along the center-post.

Claims

1. An implantable vessel filter comprising:

an elongated body having a proximal end and a distal end;

a plurality of elongated appendages configured to extend radially from a proximal portion of said elongated body in a distal direction and away from said elongated body, the distal ends of at least some of said plurality of elongated appendages being configured with hooks such that when said appendages are expanded in a body vessel, the distal end of said appendages engages an inner wall of the vessel, wherein said plurality of elongated appendages is collapsible toward said elongated body, and a distal section of said longitudinal body is configured to prevent said elongated appendages from entangling with each other when collapsed.

2. The implantable vessel filter according to claim 1, wherein said elongated body is configured with grooves for receiving said hooks and preventing said hooks from interlocking with each other when said filter is in a collapsed position.

3. The implantable vessel filter according to claim 1, wherein said plurality of elongated appendages comprise a first set of legs forming a first filter basket and a second set of legs forming a second filter basket distal to said first filter basket, each of said second set of legs further comprising a hook attached to the proximal end of each of said legs, said elongated body being configured with grooves for separating said hooks from each other while the filter is in the collapsed position.

4. The implantable vessel filter according to claim 3, wherein the material of each of said elongated appendages comprises a compressible spring metal.

5. The implantable vessel filter according to claim 3, wherein the material of each of said elongated appendages comprises a shape memory metal.

6. The implantable vessel filter according to claim 5, wherein said shape memory metal comprises Nitinol.

7. The implantable vessel filter according to claim 3, wherein said hooks are configured to engage and penetrate said inner wall of the vessel in an expanded position of said filter, each of said hooks being formed with a maximum migration resistance force such that a proximal withdrawal force applied to said hooks that is in excess of said filter migration resistance force will cause said hooks to straighten and bend toward the filter longitudinal axis.

8. The implantable vessel filter according to claim 1 wherein said elongated body extends proximally beyond an interconnection between said elongated body and said plurality of elongated appendages.

9. The implantable vessel filter according to claim 8 further comprising an interlocking mechanism connected to the proximal end of said elongated body.

10. The implantable vessel filter according to claim 8 further comprising a hook positioned at the proximal end of said elongated body.

11. The implantable vessel filter according to claim 1 wherein the distal end of said elongated body extends beyond the distal ends of said plurality of elongated appendages when said elongated appendages are collapsed.

12. The implantable vessel filter according to claim 11 further comprising an interlocking mechanism connected to the distal end of said elongated body.

13. The implantable vessel filter according to claim 11 further comprising a hook positioned at the distal end of said elongated body.

14. The implantable vessel filter according to claim 1, wherein said elongated body further comprises a plurality of flanges positioned at the distal portion of said elongated body, said flanges being configured to separate said hooks when said elongated appendages are compressed toward the elongated body.

15. The implantable vessel filter according to claim 14, wherein said flanges are evenly spaced around a circumferential surface of said elongated body.

16. The implantable vessel filter according to claim 3, wherein said second set of legs comprises six legs, and said elongated body further comprises six flanges evenly spaced and positioned at the distal portion of said elongated body, said flanges being configured to separate said hooks when said elongated appendages are compressed toward the elongated body.

17. The implantable vessel filter according to claim 1, wherein said elongated body comprises a plurality of grooves for interfacing with said plurality of elongated appendages when said elongated appendages are collapsed onto said elongated body.

18. In a removable blood clot filter having a plurality of appendages with hooks for engaging an inner wall of a blood vessel, the improvement comprising:

a center-post configured to prevent said appendages from entangling with each other when said plurality of appendages are compressed toward a longitudinal axis of said filter.

19. The improvement according to claim 18, wherein said center-post further comprises grooves for receiving said hooks when said plurality of appendages are compressed onto said center-post.

20. The improvement according to claim 18, wherein said plurality of appendages form at least two filter baskets when said appendages are in an expanded position.

21. The improvement according to claim 18, wherein said plurality of appendages are made from a material comprising compressible spring metal.

22. The improvement according to claim 18, wherein said plurality of appendages are made from a material comprising shape memory metal.

23. The improvement according to claim 18, further comprising a disk positioned on said center-post, wherein said disk comprises slots on the circumference of said disk for receiving said appendages.

24. The improvement according to claim 19, wherein said plurality of appendages comprises appendages of varying lengths, and said grooves are configured with varying lengths corresponding to the length of said appendages.

25. The improvement according to claim 19, wherein said grooves are configured in a staggered pattern around the circumference of said center-post.

26. The improvement according to claim 19, wherein said grooves are configured in a step-wise fashion along the circumferential direction around the center-post.

27. The improvement according to claim 18, further comprising an attachment positioned on said center-post, wherein said attachment having a plurality of cavities for receiving said appendages.

28. The improvement according to claim 18, further comprising a plurality of attachments positioned on said center-post, wherein each of said plurality of attachments is configured with cavities for receiving at least one of said appendages.

29. A method of utilizing an implantable vessel filter having a plurality of legs with a hook at the distal end of each of said legs, comprising the step of:

compressing said plurality of legs toward a center-post and placing each of said hooks within a corresponding groove on said center-post.

30. The method according to claim 29, further comprising the steps of:

inserting said implantable vessel filter into a body vessel of a patient; and

deploying said implantable vessel filter in said body vessel.

31. The method according to claim 30, further comprising the steps of:

collapsing said legs toward said center-post and placing each of said hooks within a corresponding groove on said center-post; and

retrieving said implantable vessel filter from said vessel.