EMBOLUS BLOOD CLOT FILTER WITH POST DELIVERY ACTUATION

• US 20090306703A1
• Filed: 12/29/2006
• Published: 12/10/2009
• Est. Priority Date: 12/30/2005
• Status: Active Grant

• Current Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Chanduszko, Andrzej J., Kashkarov, Alexander Germanovich
• Granted Patent: US 8,092,484 B2
• Time in Patent Office: Days
• 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 2/0108 Both ends closed, i.e. legs gathered at both ends
• CPC Class Codes: A61F 2002/016 made from wire-like elements
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2230/005 Rosette-shaped, e.g. star-shaped
• CPC Class Codes: A61F 2230/0058 X-shaped
• CPC Class Codes: A61F 2230/0078 hyperboloidal
• CPC Class Codes: A61F 2230/008 paraboloidal
• CPC Class Codes: A61F 2250/0029 differing in bending or flexure capacity
• CPC Class Codes: A61F 2250/0031 made from both resorbable and non-resorbable prosthetic parts, e.g. adjacent parts
• CPC Class Codes: A61F 2250/0071 breakable or frangible

Abstract

A removable blood clot filter includes a number of locator members and anchor members, and a bio-resorbable structure that causes locator members and/or anchor members to deploy to an initial configuration which changes when the bio-resorbable structure is resorbed. The bio-resorbable structure causes the filter locator members and/or anchor members to press against the vessel wall sufficient to locate and anchor the filter upo delivery. After the bio-resorbable structure is resorbed, the locator member'"'"'s and/or anchor members change shape to apply less pressure against the vessel wall. The bio-resorbable structure may be activated by exposure to radiation so that actuation of the locator members and/or anchor members can be enabled or initiated by a clinician.

Claims

1. A filter to be placed in a flow of blood through a blood vessel, the filter comprising:

two or more members positioned by a resorbable restraint coupled to spring portions of the two or more members so as to retain the members in a first configuration that provides a first spring force at a distal end of each member; and

wherein when the resorbable restraint has resorbed the members assume a second configuration that provides a second spring force at a distal end of each member, wherein the second spring force is lower than the first spring force.

2. The filter of claim 1, wherein each of the members comprises locator members, each of the locator members including a tip and an elongated portion contiguous with the spring portions such that (i) in the first configuration the locator members apply a radial force against walls of the blood vessel when the filter is positioned in the blood vessel, and (ii) in the second configuration the locator members lie approximately contiguous to and apply a nominal pressure against the wall of the blood vessel when the filter is positioned in the blood vessel.

3. The filter according to claim 2, further comprising a hub coupled to the locator members, wherein each of the spring portions comprise a curved portion having a first end and a second end, the first end being coupled to the hub and the second end being coupled to the elongated portion, wherein further the resorbable restraint encircles the curved portions near their second ends.

4. The filter according to claim 3, wherein the elongated portions of the locator members comprise a first portion linearly coupled to the curved portion, and a second portion coupled to the tip portion, each of the first and second portions being generally linear and disposed on distinct axes each oblique to the longitudinal axis.

5. The filter according to claim 4, wherein the axes of the first and second portions form angle of approximately 90 degrees.

6. The filter according to claim 1, wherein the resorbable restraint comprises a resorbable material which is resorbed in blood.

7. The filter according to claim 6, wherein the resorbable material becomes soluble in blood after exposure to radiation.

8. The filter according to claim 1, wherein the bio-resorbable restraint comprises a sleeve of a resorbable material which is resorbed in blood.

9. The filter according to claim 1, wherein the resorbable restraint comprises a cone positioned between the spring portions so as to apply a radial force on the spring portions.

10. A filter to be placed in a blood vessel, the filter comprising:

a hub disposed along a longitudinal axis;

a plurality of anchor members coupled to the hub, each anchor member including a hook and configured so that the hook penetrates a wall of the blood vessel when the filter is disposed in the blood vessel;

a plurality of locator members coupled to the hub, each locator member including;

a first portion proximate the hub, the first portion including a spring portion;

a second portion that extends from the first portion along a first axis;

a third portion that extends from the second portion along a second axis, wherein the second axis is distinct from the first axis; and

a tip portion that extends from the third portion along a tip axis, wherein the tip axis is distinct from the first and second axes; and

a resorbable restraint coupled to the spring portions so as to retain the locator members in a first configuration that provides a first spring force at a distal end of each locator member, and

wherein when the resorbable restraint has resorbed each locator member assumes a second configuration that provides a second spring force at a distal end of each member, wherein the second spring force is lower than the first spring force.

11. The filter according to claim 10, wherein each of the first portions comprise a curved portion having at a first end coupled to the hub and a second end coupled to the second portion, wherein further the resorbable restraint encircles the curved portion near the second end.

12. The filter according to claim 10, wherein the resorbable restraint comprises a loop of a resorbable material which is resorbed in blood.

13. The filter according to claim 12, wherein the resorbable material becomes soluble in blood after exposure to ultraviolet radiation.

14. The filter according to claim 10, wherein the resorbable restraint comprises a sleeve of a resorbable material which is resorbed in blood.

15. The filter according to claim 10, wherein the resorbable restraint comprises a plug positioned between respective spring portions so as to apply a radial force on the spring portions.

16. The filter according to claim 10, wherein:

each of the plurality of anchor members further comprise an extended rigid portion coupled to the hook, and a flexible portion coupled to the hub, and

the filter further comprises a sleeve surrounding the flexible portion of the plurality of anchor members, the sleeve comprising a bio-resorbable material configured to restrain the plurality of anchors.

17. The filter according to claim 16, wherein the sleeve comprises a length of bio-resorbable material wrapped around the flexible portions of the plurality of anchor members.

18. The filter according to claim 16, wherein the sleeve comprises a plurality of bands of bio-resorbable material position around the flexible portions of the plurality of anchor members.

19. The filter according to claim 16, wherein the tip portion of each of the plurality of locator members further comprises a hook and a bio-resorbable material encompassing at least a portion of the hook.

20. The filter according to claim 10, wherein the tip portion of each of the plurality of locator members further comprises a hook and a bio-resorbable material encompassing at least a portion of the hook.

21. The filter according to claim 19, wherein the material includes a smooth contact surface for surface contact with a vessel wall.

22. The filter according to claim 16, wherein the tip portion of each of the plurality of locator members further comprises a hook including a bio-resorbable material and the sleeve is configured to resorb after the bio-resorbable material of the hooks has resorbed.

23. A filter to be placed in a blood vessel, comprising:

a hub disposed along a longitudinal axis;

a plurality of anchor members coupled to the hub, each anchor member comprising a hook, an extended rigid portion coupled at a first end to the hook, and a flexible portion coupled to the hub;

a sleeve surrounding the flexible portion of the plurality of anchor members, the sleeve comprising a bio-resorbable material configured to restrain the plurality of anchor members; and

a plurality of locator members coupled to the hub, each locator member including a tip portion, wherein each locator member is configured so that the tip portion engages the wall of the blood vessel when the filter is disposed in the blood vessel,

wherein each of the plurality of anchor members is configured so that (i) when the filter is disposed in the blood vessel and the sleeve surrounds the flexible portion of the plurality of anchor members the members assume a first configuration which applies a first radial spring force at the hook end, and (ii) when the sleeve has resorbed, the anchor members assume a second configuration in which a second radial spring force is applied at the hook end, wherein the second radial spring force is less than the first radial spring force.

24. The filter according to claim 23, wherein the sleeve comprises a length of bio-resorbable material wrapped around the flexible portions of the plurality of anchor members.

25. The filter according to claim 23, wherein the sleeve comprises a plurality of bands of bio-resorbable material position around the flexible portions of the plurality of anchor members.

26. A filter to be placed in a blood vessel, comprising:

a plurality of filter members; and

means for delaying actuation of a filter member following delivery of the filter into the blood vessel.

27. A method of implanting a blood filter into a blood vessel, comprising:

maintaining filter members in a first configuration after implantation in a blood vessel; and

moving filter members to second configuration after an extended exposure to blood.

28. The method of claim 27, further comprising bending the filter members to impart a spring force onto the filter members and constraining the filter members via a resorbable restraint or retaining member.

29. The method of claim 28, wherein the moving comprises actively causing the resorbability of the restraint or retaining member via radiation with a predetermined wavelength of light.

30. A filter to be placed in a blood vessel, the filter comprising:

a plurality of elongate members coupled at one end and diverging from each other at another end;

a bio-resorbable material covering at least a portion of the one end; and

a non-resorbable annulus surrounding the elongate members proximate the one end and contiguous to the bioresorbable material so that upon resorption of the bioresorbable material, the sleeve is operable to slide towards the one end.