Embolic protection systems having radiopaque filter mesh

• US 8,152,833 B2
• Filed: 02/20/2007
• Issued: 04/10/2012
• Est. Priority Date: 02/22/2006
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Tyco Healthcare Group LP (Medtronic Plc)
• Inventors: Zaver, Steven G., Kusleika, Richard S., Carion, Brian S.
• Primary Examiner(s): Severson, Ryan
• Assistant Examiner(s): Cronin, Ashley
• Application Number:
  US11/708,651
• Publication Number:
  US 20070208373A1
• Time in Patent Office: 1,876 Days
• Field of Search: 606/108, 606/194, 606/200, 623 111- 113, 623/1.15, 623/1.2, 623/1.34
• 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 2/06 Blood vessels
• CPC Class Codes: A61F 2/844 folded prior to deployment
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• 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 2230/0006 circular
• CPC Class Codes: A61F 2230/0067 conical
• CPC Class Codes: A61F 2250/0018 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0032 differing in radiographic density
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2310/00071 Nickel or Ni-based alloys
• CPC Class Codes: A61F 2310/00137 Tungsten or W-based alloys
• CPC Class Codes: A61F 2310/00149 Platinum or Pt-based alloys

Abstract

A device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body. 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. The filter element includes a mesh including strands, each strand having a diameter. The mesh includes at least one radiopaque strand and at least one non-radiopaque strand, and wherein each strand has an index of wire stiffness EI, where EI is the mathematical product of the Young'"'"'s modulus (E) and the second moment of area (I), and wherein the largest EI of a strand is no more than five times the smallest EI of a strand.

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 mesh comprising strands, each strand having a diameter, the mesh comprising at least one radiopaque strand and at least one non-radiopaque strand, the at least one radiopaque strand and the at least one non-radiopaque strand each having different diameters, and wherein each strand has an index of wire stiffness EI, where EI is the mathematical product of the Young'"'"'s modulus (E) and the second moment of area (I), and wherein the EI of all strands in the mesh is no more than five times the EI of the strand having the smallest EI of any of the strands.

2. The 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.

3. The 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.

4. The device of claim 3, wherein the filter element has a proximal facing opening portion and this portion is radiopaque.

5. The device of claim 1, wherein the filter element is self-expanding.

6. The device of claim 1, wherein the filter element is self-contracting.

7. The device of claim 1, wherein the mesh is tubular.

8. The device of claim 7, wherein the mesh is braided.

9. The device of claim 1, wherein each strand has a round cross-section.

10. The device of claim 9, wherein the mesh comprises only two types of strands, a first type being a radiopaque strand and having a diameter D1 and a second type being a non-radiopaque strand and having a diameter D2.

11. The device of claim 10, wherein both the first and second types of strands are monofilaments.

12. The device of claim 1, wherein the Young'"'"'s modulus of the radiopaque strand and the Young'"'"'s modulus of the non-radiopaque strand differ by 10 percent or more.

13. The device of claim 1, wherein the Young'"'"'s modulus of the radiopaque strand and the Young'"'"'s modulus of the non-radiopaque strand differ by 20 percent or more.

14. The device of claim 1, wherein the mesh comprises more radiopaque strands than non-radiopaque strands.

15. The device of claim 1, wherein the mesh comprises more non-radiopaque strands than radiopaque strands.

16. The device of claim 1, wherein the EI of all strands in the mesh is no more than four times the EI of the strand having the smallest EI of any of the strands.

17. The device of claim 1, wherein the EI of all strands in the mesh is no more than two times the EI of the strand having the smallest EI of any of the strands.

18. The device of claim 17, wherein the largest diameter of a strand is no more than two times the smallest diameter of any other strand.

19. The device of claim 1, wherein the EI of all strands in the mesh is no more than 1.5 times the EI of the strand having the smallest EI of any of the strands.

20. The device of claim 1, wherein the EI of all strands in the mesh is no more than 1.3 times the EI of the strand having the smallest EI of any of the strands.

21. The device of claim 1, wherein the mesh comprises pores and when the mesh is at rest in free space no pore has an area more than five times the mesh pore size, the mesh pore size being the average area of five pores serially adjacent to the pore.

22. The device of claim 1, wherein the mesh comprises pores and when the mesh is at rest in free space no pore has an area more than four times the mesh pore size, the mesh pore size being the average area of five pores serially adjacent to the pore.

23. The device of claim 1, wherein the mesh comprises pores and when the mesh is at rest in free space no pore has an area more than three times the mesh pore size, the mesh pore size being the average area of five pores serially adjacent to the pore.

24. The device of claim 1, wherein the mesh comprises pores and when the mesh is at rest in free space no pore has an area more than two times the mesh pore size, the mesh pore size being the average area of five pores serially adjacent to the pore.

25. The device of claim 1, wherein the mesh comprises pores and when the mesh is at rest in free space no pore has an area more than 1.5 times the mesh pore size, the mesh pore size being the average area of five pores serially adjacent to the pore.

26. The device of claim 1, wherein the mesh comprises pores and when the mesh is at rest in free space no pore has an area more than 1.2 times the mesh pore size, the mesh pore size being the average area of five pores serially adjacent to the pore.

27. The device of claim 1, wherein the mesh comprises at least two types of strands, each strand having a round cross-section, a first type of strand being a radiopaque strand and having a diameter D1 and a second type of strand being a non-radiopaque strand and having a diameter D2, diameter D1 being larger than diameter D2, wherein the mesh comprises pores and when the mesh is at rest in free space no pore adjacent to a strand having a diameter D1 has an area more than five times the mesh pore size, the mesh pore size being the average area of five pores serially adjacent to the pore.

28. The device of claim 1, wherein the mesh comprises at least two types of strands, each strand having a round cross-section, a first type of strand being a radiopaque strand and having a diameter D1 and a second type of strand being a non-radiopaque strand and having a diameter D2, diameter D1 being larger than diameter D2, wherein the mesh comprises pores and when the mesh is at rest in free space no pore adjacent to a strand having a diameter D1 has an area more than two times the mesh pore size, the mesh pore size being the average area of five pores serially adjacent to the pore.

29. The device of claim 1, wherein the at least one radiopaque strand is made of homogeneous metal or metal alloy.

30. The device of claim 29, wherein the at least one radiopaque strand is selected from the group consisting of strands made of gold, platinum, tungsten, tantalum, and alloys thereof.

31. The device of claim 1, wherein the at least one non-radiopaque strand is made of metal.

32. The device of claim 31, wherein the at least one non-radiopaque strand is selected from the group consisting of strands made of stainless steel and nitinol.

33. The device of claim 31, wherein the at least one non-radiopaque strand is superelastic.

34. The device of claim 1, wherein the largest diameter of a strand is no more than five times the smallest diameter of any other strand.

35. The device of claim 1, wherein the largest diameter of a strand is no more than four times the smallest diameter of any other strand.

36. The device of claim 1, wherein the largest diameter of a strand is no more than two times the smallest diameter of any other strand.

37. The device of claim 1, wherein the largest diameter of a strand is no more than 1.5 times the smallest diameter of any other strand.

38. The device of claim 1, wherein the at least one radiopaque strand is a monofilament.

39. The device of claim 1, wherein the at least one non-radiopaque strand is a monofilament.

40. The device of claim 1, wherein the at least one radiopaque strand is a multifilament wire.

41. The device of claim 1, wherein at least one strand is a monofilament wire from which some material has been removed in the form of slots.

42. The device of claim 1, wherein the at least one non-radiopaque strand is made of nitinol.

43. The device of claim 1, wherein the Young'"'"'s modulus of the at least one radiopaque strand is less than the Young'"'"'s modulus of the at least one non-radiopaque strand.

44. The device of claim 1, wherein the Young'"'"'s modulus of the at least one radiopaque strand is greater than the Young'"'"'s modulus of the at least one non-radiopaque strand.

45. The device of claim 1, wherein the at least one radiopaque strand has a larger diameter than the at least one non-radiopaque strand.

46. The device of claim 1, wherein the Young'"'"'s modulus of the radiopaque strand and the Young'"'"'s modulus of the non-radiopaque strand are different.

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

providing the device for filtering emboli, the device 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 mesh comprising strands, each strand having a diameter, the mesh comprising at least one radiopaque strand and at least one non-radiopaque strand, the at least one radiopaque strand and the at least one non-radiopaque strand each having different diameters, and wherein each strand has an index of wire stiffness EI, where EI is the mathematical product of the Young'"'"'s modulus (E) and the second moment of area (I), and wherein the EI of all strands in the mesh is no more than five times the EI of the strand having the smallest EI of any of the strands;

delivering the device percutaneously to a region of interest in the lumen of the patient'"'"'s body; and

using fluoroscopy to visualize the filter element in the lumen of the patient'"'"'s body.

48. The method of claim 47, wherein the device further comprises an elongate support member and wherein the filter element is carried on a portion of the elongate support member.

49. The method of claim 47, 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.

50. The method of claim 49, wherein the filter element has a proximal facing opening portion and this portion is radiopaque.

51. The method of claim 50, wherein the proximal facing opening portion of the filter element is visualized to confirm that this portion is adequately deployed against the walls of the vessel.

52. The method of claim 47, wherein the filter element is self-expanding.

53. The method of claim 47, wherein the filter element is self-contracting.

54. The method of claim 47, wherein the at least one radiopaque strand is made of homogeneous metal or metal alloy.

55. The method of claim 47, wherein the Young'"'"'s modulus of the at least one radiopaque strand is less than the Young'"'"'s modulus of the at least one non-radiopaque strand.

56. The method of claim 47, wherein the Young'"'"'s modulus of the at least one radiopaque strand is greater than the Young'"'"'s modulus of the at least one non-radiopaque strand.

57. The method of claim 47, wherein the at least one radiopaque strand has a larger diameter than the at least one non-radiopaque strand.

58. The method of claim 47, wherein the Young'"'"'s modulus of the radiopaque strand and the Young'"'"'s modulus of the non-radiopaque strand are different.

59. A mesh comprising strands, each strand having a diameter, the mesh comprising at least one radiopaque strand and at least one non-radiopaque strand, the at least one radiopaque strand and the at least one non-radiopaque strand each having different diameters, and wherein each strand has an index of wire stiffness EI, where EI is the mathematical product of the Young'"'"'s modulus (E) and the second moment of area (I), and wherein the EI of all strands in the mesh is no more than five times the EI of the strand having the smallest EI of any of the strands.

60. The mesh of claim 59, wherein the mesh is tubular.

61. The mesh of claim 60, wherein the mesh is braided.

62. The mesh of claim 59, wherein the Young'"'"'s modulus of the radiopaque strand and the Young'"'"'s modulus of the non-radiopaque strand differ by 10 percent or more.

63. The mesh of claim 59, wherein the Young'"'"'s modulus of the radiopaque strand and the Young'"'"'s modulus of the non-radiopaque strand differ by 20 percent or more.

64. The mesh of claim 59, wherein the EI of all strands in the mesh is no more than four times the EI of the strand having the smallest EI of any of the strands.

65. The mesh of claim 59, wherein the EI of all strands in the mesh is no more than two times the EI of the strand having the smallest EI of any of the strands.

66. The mesh of claim 59, wherein the EI of all strands in the mesh is no more than 1.5 times the EI of the strand having the smallest EI of any of the strands.

67. The mesh of claim 59, wherein the EI of all strands in the mesh is no more than 1.3 times the EI of the strand having the smallest EI of any of the strands.

68. The mesh of claim 59, wherein the at least one radiopaque strand is made of homogeneous metal or metal alloy.

69. The mesh of claim 59, wherein the Young'"'"'s modulus of the at least one radiopaque strand is less than the Young'"'"'s modulus of the at least one non-radiopaque strand.

70. The mesh of claim 59, wherein the Young'"'"'s modulus of the at least one radiopaque strand is greater than the Young'"'"'s modulus of the at least one non-radiopaque strand.

71. The mesh of claim 59, wherein the at least one radiopaque strand has a larger diameter than the at least one non-radiopaque strand.

72. The mesh of claim 59, wherein the Young'"'"'s modulus of the radiopaque strand and the Young'"'"'s modulus of the non-radiopaque strand are different.