Variable thickness embolic filtering devices and method of manufacturing the same

• US 20030004536A1
• Filed: 06/29/2001
• Published: 01/02/2003
• Est. Priority Date: 06/29/2001
• Status: Active Grant

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Inventors: Boylan, John F., Tarapata, Christopher J., Padilla, Orlando M.
• Granted Patent: US 7,338,510 B2
• Time in Patent Office: Days
• US Class Current: 606/200
• CPC Class Codes: A61F 2/0108 Both ends closed, i.e. legs gathered at both ends
• 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

Abstract

A strut assembly to be used in conjunction with an embolic filtering device has varying strut thicknesses, with the thickness selected based at least in part on the flexing characteristics of the particular portion of the strut assembly. The strut assembly is formed with patterns having flexing portions and stable portions, with the flexing portions contributing to the flexibility of the strut assembly during delivery and recovery in the patient'"'"'s vasculature. The stable portions remain relatively unflexed and stiff when being delivered or recovered from the patient'"'"'s vasculature. The stable portions provide strength and increased radiopacity to the strut assembly which is needed when the strut assembly is deployed in the body vessel. The flexing portions act much like a mechanical hinges in providing the needed flexibility to resiliently bend when being delivered through tortuous anatomy of the patient.

Claims

1. A strut assembly for an embolic filtering device for filtering embolic debris from a patient'"'"'s vasculature, comprising:

a plurality of struts arranged to create a desired composite strut structure which is adapted to move between a collapsed position and an expanded position, the strut structure including;

flexing portions which flex when subjected to bending forces that may be developed when the strut assembly is being delivered through the patient'"'"'s vasculature; and

stable portions that remain relatively stiff when being delivered through the patient'"'"'s vasculature.

2. The strut assembly of claim 1, wherein the stable portions provide structural strength to maintain the strut assembly in the expanded position.

3. The strut assembly of claim 1, wherein flexing portions interconnect adjacent stable portions.

4. The strut assembly of claim 1, wherein the flexing portions undergo little or no deformation when subjected to bending forces developed during delivery through the patient'"'"'s vasculature.

5. The strut assembly of claim 4, wherein the flexing portions are made from a material which is self-expanding.

6. The strut assembly of claim 1, wherein the struts are made from a material which is self-expanding.

7. The strut assembly of claim 6, wherein the material is nickel-titanium.

8. The strut assembly of claim 1, wherein each strut has an inside surface and an outside surface which define a strut thickness, the strut thickness in the stable portions being generally greater than the strut thickness in the flexing portions.

9. The strut assembly of claim 8, wherein the strut thickness in the flexing portions define a nominal strut thickness and the strut thickness in the stable portions define a greater-than-nominal strut thickness.

10. The strut assembly of claim 9, wherein the nominal strut thickness is about 10% or less of the greater-than-nominal strut thickness.

11. The strut assembly of claim 9, wherein the nominal strut thickness is about 50% or less of the greater-than-nominal strut thickness.

12. The strut assembly of claim 9, wherein the nominal strut thickness is about 80% or less of the greater-than-nominal strut thickness.

13. The strut assembly of claim 9, wherein some of the flexing portions have less than nominal strut thickness.

14. The strut assembly of claim 8, wherein some flexing portions have strut thickness different from other flexing portions but less than the strut thickness in the stable portions.

15. The strut assembly of claim 1, wherein each strut has a particular strut width, the strut widths in the stable portions being generally greater than the strut widths in the flexing portions.

16. The strut assembly of claim 15, wherein the strut widths in the flexing portions define a nominal strut width and the strut width in the stable portions define a greater-than-nominal strut width.

17. The strut assembly of claim 8, wherein each strut has a particular strut width, the strut widths in the stable portions being generally greater than the strut widths in the flexing portions.

18. The strut assembly of claim 17, wherein the strut widths in the flexing portions define a nominal strut width and the strut width in the stable portions define a greater-than-nominal strut width.

19. The strut assembly of claim 16, wherein some of the flexing portions have less than nominal strut widths.

20. The strut assembly of claim 19, wherein some flexing portions have strut widths different from other flex portions but less than the strut widths in the stable portions.

21. A strut assembly for an embolic filtering device for filtering embolic debris from a patient'"'"'s vasculature, comprising:

a plurality of struts arranged to create a desired composite strut assembly which is adapted to move between a collapsed position and an expanded position, each strut having an inner surface and an outer surface which defines a particular strut thickness, wherein portions of the composite strut assembly have strut thickness which are less that the strut thickness of the remaining struts to impart flexibility to the composite strut assembly to resiliently flex when being delivered through the patient'"'"'s vasculature.

22. The strut assembly of claim 21, wherein the portions of the composite strut assembly having larger strut thickness undergo little or no deformation when subjected to bending forces developed during delivery of the strut assembly through the patient'"'"'s vasculature.

23. The strut assembly of claim 21, wherein the struts are made from a material which is self-expanding.

24. The strut assembly of claim 23, wherein the material is nickel-titanium.

25. The strut assembly of claim 21, wherein each strut has a particular strut width and the strut widths in the portions of the composite strut assembly having smaller strut widths are generally less than the strut widths of the remaining struts.

26. The strut assembly of claim 21, wherein the portions of the composite strut assembly having smaller strut thickness enhance the movement of the strut assembly between the collapsed position and the expanded position.

27. The strut assembly of claim 23, wherein the portions of the composite strut assembly having smaller strut thickness enhance the movement of the strut assembly between the collapsed position and the expanded position.

28. The strut assembly of claim 25, wherein the strut thickness in the portions of the composite strut assembly having smaller strut thickness are non-uniform.

29. The strut assembly of claim 21, wherein the portions of the composite strut assembly having smaller strut thickness define a nominal strut thickness and the remaining struts define a greater-than-nominal strut thickness.

30. An embolic filtering device for filtering embolic debris from a patient'"'"'s vasculature, comprising:

a filtering assembly including an expandable strut assembly and a filter element attached thereto;

wherein the strut assembly is adapted to move between a collapsed position and an expanded position and has flexing portions which flex when subjected to bending forces that may be developed when the filtering assembly is being passed through the patient'"'"'s vasculature and stable portions that remain relatively stiff when the filtering assembly is being passed through the patient'"'"'s vasculature.

31. The filtering device of claim 30, further including an elongated member having a proximal end and a distal end, the filtering assembly being mounted near the distal end, the elongated member being steerable to place the filtering assembly in the desired position within the patient'"'"'s vasculature.

32. The filtering device of claim 30, wherein flexing portions interconnect adjacent stable portions.

33. The filtering device of claim 30, wherein the flexing portions undergo little or no deformation when subjected to bending forces developed during passage through the patient'"'"'s vasculature.

34. The filtering device of claim 33, wherein the flexing portions of the strut assembly are made from a material which is self-expanding.

35. The filtering device of claim 30, wherein the strut assembly is made from a material which is self-expanding.

36. The filtering device of claim 35, wherein the material is nickel-titanium.

37. The filtering device of claim 30, wherein the strut assembly is made from a plurality of struts, each strut having an inside surface and an outside surface which define a strut thickness, the strut thickness in the stable portions being generally greater than the strut thickness in the flexing portions of the strut assembly.

38. The filtering device of claim 37, wherein the strut thickness in the flexing portions define a nominal strut thickness and the strut thickness in the stable portions define a greater-than-nominal strut thickness.

39. The filtering device of claim 38, wherein some of the flexing portions have less than nominal strut thickness.

40. The filtering device of claim 38, wherein some flexing portions have strut thickness different from other flexing portions but less than the strut thickness in the stable portions.

41. The filtering device of claim 30, wherein the strut assembly is formed from a plurality of struts, each strut having a particular strut width, the strut widths in the stable portions being generally greater than the strut widths in the flexing portions of the strut assembly.

42. The filtering device of claim 41, wherein the strut widths in the flexing portions define a nominal strut width and the strut width in the stable portions define a greater-than-nominal strut width.

43. The filtering device of claim 37, wherein each strut has a particular strut width, the strut widths in the stable portions being generally greater than the strut widths in the flexing portions.

44. The filtering device of claim 30, wherein the flexing portions of the strut assembly enhance the movement of the strut assembly between the first collapsed position and the second delivery position.

45. The filtering device of claim 35, wherein the flexing portions of the strut assembly enhance the movement of the strut assembly between the first collapsed position and the second delivery position.

47. The filtering device of claim 46, further including an elongated member having a proximal end and a distal end, the filtering assembly being mounted near the distal end, the elongated member being steerable to place the filtering assembly in the desired position within the patient'"'"'s vasculature.

48. The filtering device of claim 46, wherein the portions of the composite strut assembly having smaller strut thickness undergo little or no deformation when subjected to bending forces developed during delivery of the filtering assembly through the patient'"'"'s vasculature.

49. The filtering device of claim 46, wherein each strut has a particular strut width and the strut widths in the portions of the composite strut assembly having smaller strut thickness are generally less than the strut widths of the remaining struts.

50. The filtering device of claim 46, wherein the portions of the composite strut assembly having smaller strut thickness enhances the movement of the strut assembly between the collapsed position and the expanded position.

46. An embolic filtering device for filtering embolic debris from a patient'"'"'s vasculature, comprising:

a filtering assembly including an expandable strut assembly and a filter element attached thereto, the strut assembly being adapted to move between a first collapsed position and an expanded position and being formed from a plurality of struts arranged to create a desired composite strut structure, each strut having an inner surface and an outer surface which defines a particular strut thickness, wherein;

portions of the composite strut assembly have strut thickness which are less that the strut thickness of the remaining struts forming the strut assembly to impart flexibility to the composite strut assembly to allow the strut assembly to resiliently flex while being delivered through the patient'"'"'s vasculature.

51. A method of manufacturing a strut assembly having variable thickness, comprising:

providing a generally tubular member with a desired thickness, the tubular member having a outer surface and an inner surface;

varying the thickness of selected portions of the tubular member; and

removing material from the tubular section to form a desired strut pattern which forms the strut assembly.

52. The method of claim 51, wherein:

the step of removing material from the tubular member includes the step of laser cutting the desired pattern into the tubular member.

53. The method of claim 51, wherein:

the step of varying the thickness of selected portions of the tubular member includes;

mounting the tubular member on a rotating mechanism;

rotating the tubular member;

contacting the outer surface of the tubular member with a cutting device which removes selected amounts from the tubular member until the desired thickness is achieved in select portions of the tubular member.

54. A method of manufacturing a strut assembly having variable thickness, comprising:

selecting a strut pattern;

determining flexing portions and stable portions for the strut pattern;

forming a strut assembly with the desired strut pattern;

providing at least some flexing portions of the strut pattern of the strut assembly with a nominal thickness; and

providing at least some stable portions of the strut pattern of the strut assembly with a greater-than-nominal thickness.

55. The method of claim 54, wherein:

the flexing portions of the strut assembly have a nominal thickness achieved by reducing the thickness of select portions of the strut assembly from a greater-than-nominal thickness to a nominal thickness.

56. The method of claim 55, wherein:

the reduction of the thickness of the flexing portions of the strut assembly from a greater-than-nominal thickness to a nominal thickness includes the removal of a portion the outer surface of the strut assembly.

57. The method of claim 55, wherein:

the stable portions of the strut assembly have greater-than-nominal thickness as a result of sputter coating additional amounts of select material onto the outer surface of the strut assembly.

58. The method of claim 55, wherein:

the strut pattern of the strut assembly includes forming struts having strut widths in the flexing portion of the strut pattern which are less than the strut widths of the struts making up the stable portions of the strut pattern.

59. The method of claim 54, wherein:

the formation of the strut assembly with the desired strut pattern includes;

providing a tubular member having a variable wall thickness; and

cutting the desired strut pattern into the tubular member.

60. The method of claim 59, wherein:

the strut pattern of the strut assembly includes forming struts having strut widths in the flexing portion of the strut pattern which are less than the strut widths of the struts making up the stable portions of the strut pattern.