Embolic filters having multiple layers and controlled pore size

• US 20040153118A1
• 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: Kusleika, Richard S., Oslund, John C., Clubb, Thomas L.
• Granted Patent: US 7,220,271 B2
• Time in Patent Office: Days
• US Class Current: 606/200
• 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 2230/0008 elliptical or oval
• CPC Class Codes: A61F 2230/0067 conical
• CPC Class Codes: A61F 2230/008 paraboloidal
• CPC Class Codes: D04C 1/02 made from particular materials
• 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 element is expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained. 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. The filter element has two or more filtering layers, each filtering layer having pores, each filtering layer being adjacent to at least one other filtering layer, and at least one of the filtering layers being made of a self-expanding material.

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 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, and wherein the filter element comprises two or more filtering layers, each filtering layer comprising pores, each filtering layer being adjacent to at least one other filtering layer, and at least one of the filtering layers being made of a self-expanding material.

2. A device of claim 1, wherein each filtering layer is made of a self-expanding material.

3. 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.

4. 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.

5. 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.

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 15 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 10 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 5 percent of the average pore size.

9. 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.

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 50 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 60 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 70 percent.

13. 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.

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

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

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

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

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

19. 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.

20. 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.

21. A device of claim 20, wherein the self-expanding material comprises wires braided to form diamond-shaped pores.

22. A device of claim 1, wherein the self-expanding material comprises a single mesh rolled back on itself to form two filtering layers.

23. A device of claim 22, 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.

24. A device of claim 23, wherein the filter element comprises a drawstring tether at the proximal facing opening of the filter element.

25. A device of claim 23, wherein the self-expanding material comprises wires braided to form diamond-shaped pores.

26. A device of claim 1, wherein the filter element comprises two separate filtering layers.

27. A device of claim 26, 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.

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

29. A device of claim 26, wherein the two separate filtering layers have different average pore sizes.

30. A device of claim 26, wherein the two separate filtering layers are not attached to each other.

31. A device of claim 26, wherein the two separate filtering layers are attached to each other.

32. A device of claim 31, wherein the two separate filtering layers are attached to each other by a fixed element.

33. A device of claim 31, wherein the two separate filtering layers are attached to each other by a sliding element.

34. A device of claim 31, wherein the two separate filtering layers are attached to each other by a tether.

35. A device of claim 26, wherein a first filtering layer comprises wires braided to from diamond-shaped pores, and the second filtering layer comprises a coiled wire.

36. 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 a single mesh rolled back on itself to form two filtering layers, 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, and wherein the filter element comprises a drawstring tether at the proximal facing opening of the filter element.

37. A device of claim 36, wherein the filter element comprises wires braided to form diamond-shaped pores.

38. A device of claim 36, wherein the filter element is self-expanding.

39. 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 a single mesh rolled back on itself to form two filtering layers, a first one of the filtering layers forming an inner filter portion and a second one of the filtering layers forming an outer filter portion, wherein the inner filter portion is wrapped with a third filtering layer, and wherein the third filtering layer is not contiguous with the outer filter portion.

40. A device of claim 39, wherein the third filtering layer is made of a material selected from the group consisting of polymer filaments, braided wire, or a polymer sheet having pores.

41. A device of claim 39, wherein the filtering element is self-expanding.

42. A device of claim 39, 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.

43. A device of claim 42, wherein the filter element comprises a drawstring tether at the proximal facing opening of the filter element.

45. A device of claim 43, wherein each of the two separate filtering layers is expandable from a collapsed configuration when each filtering layer is restrained to an expanded configuration each filtering layer is unrestrained, wherein each filtering layer has proximal and distal portions and a central portion, each filtering layer having a shape in the expanded configuration which defines a cavity having a proximal facing opening.

46. A device of claim 45, wherein each filtering layer is made of a self-expanding material.

44. 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 two separate filtering layers, and wherein the two separate filtering layers are not attached to each other.

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 comprises two separate filtering layers, wherein each filtering layer has proximal and distal portions and a central portion, each filtering layer having a shape in the expanded configuration which defines a cavity having a proximal facing opening, wherein the two separate filtering layers are attached to each other by a fixed or sliding element at a distal portion of the filter element and wherein the two separate filtering layers are not attached to each other at a proximal portion of the filter element.

48. A device of claim 47, wherein the fixed or sliding element is a fixed element.

49. A device of claim 48, wherein the fixed element is a marker band.

50. A device of claim 47, wherein at least one of the two separate filtering layers comprises a single mesh rolled back on itself to form two filtering layers.

51. A device of claim 47, wherein each filtering layer is made of a self-expanding material.

52. 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 two separate filtering layers, wherein each filtering layer has proximal and distal portions and a central portion, each filtering layer having a shape in the expanded configuration which defines a cavity having a proximal facing opening, wherein the two separate filtering layers are attached to each other by a tether at a distal portion of the filter element.

53. A device of claim 52, wherein the two separate filtering layers are not attached to each other in any manner in addition to the tether.

54. A device of claim 52, wherein each filtering layer is made of a self-expanding material.

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 two separate filtering layers, wherein each filtering layer has proximal and distal portions and a central portion, each filtering layer having a shape in the expanded configuration which defines a cavity having a proximal facing opening, wherein the two separate filtering layers are attached to each other by a fixed or sliding element at a proximal portion of the filter element and wherein the two separate filtering layers are not attached to each other at a distal portion of the filter element.

56. A device of claim 55, wherein the fixed or sliding element is a fixed element.

57. A device of claim 56, wherein the fixed element is a marker band.

58. A device of claim 55, wherein each filtering layer is made of a self-expanding material.

59. A device of claim 55, wherein a first one of the filtering layers forms an inner filter portion and a second one of the filtering layers forms an outer filter portion, wherein the device further comprises an elongate support member and wherein the filter element is carried on a portion of the elongate support member, and wherein a distal portion of the first filtering layer is attached to the elongate support element by a fixed or sliding element.

60. 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 two separate filtering layers, wherein each filtering layer has proximal and distal portions and a central portion, each filtering layer having a shape in the expanded configuration which defines a cavity having a proximal facing opening, wherein the two separate filtering layers are attached to each other by a fixed or sliding element at a distal portion of the filter element, wherein the device further comprises an elongate support member, wherein the filter element is carried on a portion of the elongate support member, and wherein each of the filtering layers is attached by at least one tether to a fixed or sliding element on the elongate support element.

61. A device of claim 60, wherein each filtering layer is made of a self-expanding material.

62. 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 two separate filtering layers, wherein each filtering layer has proximal and distal portions and a central portion, each filtering layer having a shape in the expanded configuration which defines a cavity having a proximal facing opening, wherein the two separate filtering layers are attached to each other by a fixed or sliding element at a distal portion of the filter element, wherein a first one of the filtering layers forms an inner filter portion and a second one of the filtering layers forms an outer filter portion, wherein the device further comprises an elongate support member, wherein the filter element is carried on a portion of the elongate support member, and wherein the first filtering layer is attached to a fixed or sliding element on the elongate support element by at least one tether, the fixed or sliding element also being attached to the second filtering layer.

63. A device of claim 62, wherein each filtering layer is made of a self-expanding material.

64. 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 two separate filtering layers, wherein the two separate filtering layers are attached to each other by at least one tether.

65. A device of claim 64, wherein at least one of the two separate filtering layers is made of a self-expanding material.

66. 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 a first and a second filtering layer, the first filtering layer comprising wires braided to from diamond-shaped pores, and the second filtering layer comprising a coiled wire.

67. A device of claim 66, wherein each filtering layer has proximal and distal portions and a central portion, each filtering layer having a shape in the expanded configuration which defines a cavity having a proximal facing opening, and wherein the first filtering layer forms an outer filter portion and the second filtering layer forms an inner filter portion.

68. A device of claim 66, wherein at least one of the first and second filtering layers is made of a self-expanding material.

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 comprises at least a first and a second filtering layer, the first filtering layer comprising wires braided to from diamond-shaped pores, and the second filtering layer comprising a polymeric film.

70. A device of claim 69, wherein at least a portion of the second filtering layer is fixedly attached to the first filtering layer.

71. A device of claim 69, wherein each filtering layer has proximal and distal portions and a central portion, each filtering layer having a shape in the expanded configuration which defines a cavity having a proximal facing opening, and wherein the first filtering layer forms an outer filter portion and the second filtering layer forms an inner filter portion.

72. A device of claim 69, wherein the first filtering layer is made of a self-expanding material.