Embolic filters with controlled pore size

• US 20040153117A1
• Filed: 01/30/2003
• Published: 08/05/2004
• Est. Priority Date: 01/30/2003
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: ev3, Inc. (Medtronic Plc)
• Inventors: Anderson, Kent D., Kusleika, Richard S., Clubb, Thomas L., Berrada, Marwane S.
• Granted Patent: US 7,323,001 B2
• Time in Patent Office: Days
• US Class Current: 606/200
• CPC Class Codes: A61F 2/01 Filters implantable into blood vessels
• 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 2/013 Distal protection devices, i.e. devices placed distally in combination with another endovascular procedure, e.g. angioplasty or stenting
• 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 2230/0008 elliptical or oval
• CPC Class Codes: A61F 2230/0067 conical
• CPC Class Codes: A61F 2230/0069 cylindrical
• CPC Class Codes: A61F 2230/008 paraboloidal
• CPC Class Codes: D04B 1/16 synthetic threads
• CPC Class Codes: D04C 1/02 made from particular materials
• CPC Class Codes: D04C 3/48 Auxiliary devices
• CPC Class Codes: D10B 2509/06 Vascular grafts; stents

Abstract

The invention provides a device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body comprising a filter element. The filter is expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained, and the filter element comprises a self-expanding material having pores. When the filter element is in the expanded configuration, the average pore size is from 30 to 300 microns and the standard deviation of the pore size is less than 20 percent of the average pore size.

Claims

1. A device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body, comprising:

a filter element being expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained, wherein the filter element comprises a self-expanding material having pores, and when the filter element is in the expanded configuration, the average pore size is from 30 to 300 microns and the standard deviation of the pore size is less than 20 percent of the average pore size.

2. A device of claim 1, wherein when the filter element is in the expanded configuration, the average pore size is from 30 to 150 microns.

3. A device of claim 1, wherein when the filter element is in the expanded configuration, the average pore size is from 100 to 140 microns.

4. A device of claim 1, wherein when the filter element is in the expanded configuration, the average pore size is from 40 to 70 microns.

5. A device of claim 1, wherein when the filter element is in the expanded configuration, the standard deviation of the pore size is less than 15 percent of the average pore size.

6. A device of claim 1, wherein when the filter element is in the expanded configuration, the standard deviation of the pore size is less than 10 percent of the average pore size.

7. A device of claim 1, wherein when the filter element is in the expanded configuration, the standard deviation of the pore size is less than 5 percent of the average pore size.

8. A device of claim 1, wherein when the filter element is in the expanded configuration, the standard deviation of the pore size is less than 2 percent of the average pore size.

9. A device of claim 1, wherein when the filter element is in the expanded configuration, the filter element has a percent open area greater than 50 percent.

10. A device of claim 1, wherein when the filter element is in the expanded configuration, the filter element has a percent open area greater than 60 percent.

11. A device of claim 1, wherein when the filter element is in the expanded configuration, the filter element has a percent open area greater than 70 percent.

12. A device of claim 1, wherein when the filter element is in the expanded configuration, the filter element has a percent open area greater than 80 percent.

13. A device of claim 1, wherein the self-expanding material having pores has a tensile strength greater than 70,000 psi.

14. A device of claim 1, wherein the self-expanding material having pores has a tensile strength greater than 100,000 psi.

15. A device of claim 1, wherein the self-expanding material having pores has a tensile strength greater than 200,000 psi.

16. A device of claim 1, wherein the self-expanding material having pores is made of metal.

17. A device of claim 1, wherein the self-expanding material having pores is made of nitinol.

18. A device of claim 1, further comprising an elongate support member and wherein the filter element is carried on a portion of the elongate support member.

19. A device of claim 1, wherein the self-expanding material having pores comprises at least one minibraid.

20. A device of claim 1, wherein the self-expanding material having pores comprises two or more minibraids and the minibraids form a weave.

21. A device of claim 1, wherein the self-expanding material having pores comprises at least one minibraid that is helically coiled.

22. A device of claim 1, wherein the self-expanding material having pores comprises at least one stranded wire.

23. A device of claim 1, wherein the self-expanding material having pores comprises at least one fenestrated wire.

24. A device of claim 1, wherein the self-expanding material having pores comprises cylindrical wires having different diameters and have a graduated strand pattern.

25. A device of claim 1, wherein the filter element has proximal and distal portions and a central portion, the filter element having a shape in the expanded configuration which defines a cavity having a proximal facing opening.

26. A device of claim 25, wherein the self-expanding material having pores comprises wires braided to form diamond-shaped pores.

27. A device of claim 26, wherein the self-expanding material having pores comprises only axially elongated diamond-shaped pores.

28. A device of claim 26, wherein the self-expanding material having pores comprises axially shortened diamonds in the proximal portion of the filter element, square diamonds in the central portion of the filter element, and axially elongated diamonds in the distal portion of the filter element.

29. A device of claim 1, wherein the self-expanding material having pores comprises a knitted mesh.

30. A device of claim 1, wherein the self-expanding material having pores comprises braided wires and the self-expanding material having pores was made by martensitic braiding.

31. A device of claim 1, wherein the self-expanding material having pores comprises braided wires and the self-expanding material having pores was made by martensitic knitting.

32. A device of claim 1, wherein the self-expanding material having pores comprises braided wires and the self-expanding material having pores was made by wire removal.

33. A device of claim 1, wherein the self-expanding material having pores comprises braided wires and the self-expanding material having pores was made by adding wires during braiding.

34. A device of claim 1, wherein the self-expanding material having pores comprises braided wires and a portion of the wires is coated with a polymer coating that reduces the average pore size in the coated portion of the filter element.

35. A device of claim 1, wherein the filter element is an electroformed filter.

36. A device of claim 1, wherein the filter element was made by forming the filter into a mandrel.

37. A device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body, comprising:

a filter element having pores, said filter element being expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained, wherein the filter element comprises at least one minibraid.

38. A device of claim 37, wherein the filter element comprises two or more minibraids and the minibraids form a weave.

39. A device of claim 37, wherein the at least one minibraid is helically coiled.

40. A device of claim 37, wherein the filter element is self-expanding.

41. A device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body, comprising:

a filter element having pores, said filter element being expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained, wherein the filter element comprises at least one stranded wire.

42. A device of claim 41, wherein the filter element is self-expanding.

43. A device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body, comprising:

a filter element having pores, said filter element being expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained, wherein the filter element comprises at least one fenestrated wire.

44. A device of claim 43, wherein the filter element is self-expanding.

45. A device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body, comprising:

a filter element having pores, said filter element being expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained, wherein the filter element comprises cylindrical wires having different diameters and have a graduated strand pattern.

46. A device of claim 45, wherein the filter element is self-expanding.

47. A device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body, comprising:

a filter element having pores, said filter element being expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained, wherein the filter element has proximal and distal portions and a central portion, the filter element having a shape in the expanded configuration which defines a cavity having a proximal facing opening, wherein the filter element comprises wires braided to form diamond-shaped pores, and wherein the filter element comprises only axially elongated diamond-shaped pores.

48. A device of claim 47, wherein the filter element is self-expanding.

49. A device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body, comprising:

a filter element having pores, said filter element being expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained, wherein the filter element has proximal and distal portions and a central portion, the filter element having a shape in the expanded configuration which defines a cavity having a proximal facing opening, wherein the filter element comprises wires braided to form diamond-shaped pores, and wherein the filter comprises axially shortened diamonds in the proximal portion of the filter element, square diamonds in the central portion of the filter element, and axially elongated diamonds in the distal portion of the filter element.

50. A device of claim 49, wherein the filter element is self-expanding.

51. A device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body, comprising:

a filter element having pores, said filter element being expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained, wherein the filter element comprises braided wires and the filter element was made by martensitic braiding.

52. A device of claim 51, wherein the filter element is self-expanding.

53. A device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body, comprising:

a filter element having pores, said filter element being expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained, wherein the filter element comprises braided wires and the filter element was made by martensitic knitting.

54. A device of claim 53, wherein the filter element is self-expanding.

55. A device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body, comprising:

a filter element having pores, said filter element being expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained, wherein the filter element comprises braided wires and the filter element was made by adding wires during braiding.

56. A device of claim 55, wherein the filter element is self-expanding.

57. A device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body, comprising:

a filter element having pores, said filter element being expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained, wherein the filter element comprises braided wires and a portion of the wires is coated with a polymer coating that reduces the average pore size in the coated portion of the filter element.

58. A device of claim 57, wherein the filter element is self-expanding.

59. A device of claim 57, wherein the filter element has proximal and distal portions and a central portion, the filter element having a shape in the expanded configuration which defines a cavity having a proximal facing opening.

60. A device of claim 59, wherein the polymer coating is present on the proximal portion of the filter element and not present on the distal portion of the filter element.

61. A device of claim 60, wherein the polymer coating is thicker in a more proximal portion of the polymer coating than in a more distal portion of the polymer coating.

62. A device of claim 59, wherein the polymer coating is thicker in the proximal portion on the filter element than in the distal portion of the filter element.

63. A device of claim 57, wherein the polymer coating is a thermoset polymer.

64. A device of claim 57, wherein the polymer coating is a thermoplastic polymer.

65. A device of claim 57, wherein the polymer coating is a hydrogel.

66. A device of claim 57, wherein the polymer coating is a silicone.

67. A device of claim 57, wherein the polymer coating is a heat-set silicone.

68. A device of claim 57, wherein the device was made by dipping the filter element in a polymer solution and removing it at a programmed rate.

69. A device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body, comprising:

a filter element having pores, said filter element being expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained, wherein the filter element is an electroformed filter.

70. A device of claim 69, wherein the filter element is self-expanding.

71. A device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body, comprising:

a filter element having pores, said filter element being expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained, wherein the filter element was made by forming the filter into a mandrel.

72. A device of claim 71, wherein the filter element is self-expanding.

73. A device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body, comprising:

a filter element having pores, said filter element being expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained, wherein the filter element has proximal and distal portions and a central portion, the filter element having a shape in the expanded configuration which defines a cavity having a proximal facing opening, wherein the filter element comprises wires braided to form diamond-shaped pores, and wherein the filter element comprises a greater density of wires in the proximal portion than in the distal portion.

74. A device of claim 73, wherein the filter element is self-expanding.