DEVICES AND METHODS FOR CONTROLLING EXPANDABLE PROSTHESES DURING DEPLOYMENT

• US 20080132989A1
• Filed: 05/23/2007
• Published: 06/05/2008
• Est. Priority Date: 06/28/2004
• Status: Active Grant

• Current Assignee: JW Medical Systems Ltd
• Original Assignee: XTENT, Inc.
• Inventors: Lin, Stuart, Henderson, Dawn M., Snow, David W., Robinson, Timothy W.
• Granted Patent: US 8,317,859 B2
• Time in Patent Office: Days
• US Class Current: 623/1.12
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2/9517 handle assemblies therefor
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2/966 with relative longitudinal movement between outer sleeve and prosthesis, e.g. using a push rod
• CPC Class Codes: A61F 2/97 the outer sleeve being splittable
• CPC Class Codes: A61F 2002/826 more than one stent being applied sequentially
• CPC Class Codes: A61F 2002/9505 having retaining means other than an outer sleeve, e.g. male-female connector between stent and instrument
• CPC Class Codes: A61F 2002/9665 with additional retaining means

Abstract

Prosthesis delivery devices and methods are provided that enable precise control of prosthesis position during deployment. The catheter for delivering a prosthesis to a treatment site in a body lumen typically carries one or more self-expanding tubular prostheses within a sheath. A radially expandable control member is positionable within the prostheses and has an expanded shape which engages an inner surface of the prostheses to urge the prostheses outwardly against the sheath. The radially expandable control member therefore controls axial position of the prostheses during deployment. Thus one or more prostheses may be deployed at a treatment site precisely. When multiple prostheses are deployed, excessive spacing or overlap between adjacent prostheses is minimized. The prostheses of the present invention are often deployed in stenotic lesions in peripheral arteries as well as coronary arteries and other body lumens.

Claims

1. A catheter for delivering a prosthesis to a treatment site in a body lumen, the catheter comprising:

a pusher tube having a proximal end and a distal end;

a sheath slidably disposed over the pusher tube;

one or more self-expanding tubular prostheses carried within the sheath which constrains the prostheses in a radially contracted configuration, the prostheses being independently releasable from the sheath as the sheath is retracted relative to the pusher tube, the prostheses resiliently expanding upon release from the sheath; and

a radially expandable control member positionable within the prostheses and having an expanded shape which engages an inner surface of at least one of the prostheses to exert an outward force against the at least one prosthesis, the control member being axially movable with the sheath so as to slide relative to the prostheses in engagement therewith as the sheath is retracted relative to the pusher tube,

wherein the pusher tube is adapted to prevent proximal motion of the one or more self-expanding prostheses as the sheath is retracted.

2. The catheter of claim 1, wherein the control member urges the prosthesis outwardly against the sheath

3. The catheter of claim 1, wherein the control member urges the prosthesis outwardly against an interior surface of the sheath.

4. The catheter of claim 1, wherein the radially expandable control member comprises a plurality of elongate struts disposed distal to the pusher tube.

5. The catheter of claim 4, wherein the struts are resilient and bend outwardly under compression.

6. The catheter of claim 1, wherein the expandable member is a metal.

7. The catheter of claim 1, wherein the expandable member comprises a basket comprising a plurality of flexible strands.

8. The catheter of claim 7, wherein at least some of the strands are oriented axially and bend outwardly under compression.

9. The catheter of claim 7, wherein the strands are metal.

10. The catheter of claim 7, wherein the strands are a polymer.

11. The catheter of claim 1, wherein the expandable member is a polymer.

12. The catheter of claim 1, wherein the expandable member comprises a balloon.

13. The catheter of claim 1, wherein the self-expanding tubular prostheses carry a therapeutic agent adapted to being released therefrom.

14. The catheter of claim 13, wherein the therapeutic agent comprises an anti-restenosis agent.

15. The catheter of claim 1, wherein the radially expandable control member engages at least two self-expanding prostheses simultaneously.

16. The catheter of claim 1, further comprising a handle near the proximal end of the pusher tube, the handle having a control mechanism adapted to actuate the sheath and the radially expandable control member during deployment of the self-expanding prostheses.

17. The catheter of claim 16, wherein the sheath is adapted to be retracted while the pusher tube remains fixed relative to the handle so as to expose at least one of the self-expanding tubular prostheses for deployment.

18. The catheter of claim 1, wherein the sheath has a distal tip interactive with the control member to enable a self-expanding prosthesis to be trapped therebetween to inhibit the prosthesis from jumping distally upon expansion.

19. The catheter of claim 18, wherein the distal tip is flared.

20. The catheter of claim 18, wherein the distal tip is expandable as the prosthesis expands.

21. The catheter of claim 18, wherein the distal tip has a plurality of axial slits.

22. The catheter of claim 1, wherein the one or more self-expanding prostheses comprise a plurality of self-expanding prostheses.

23. The catheter of claim 22, wherein the self-expanding tubular prostheses have a length in the range of about 2 mm to about 50 mm.

24. The catheter of claim 22, wherein each of the self-expanding prostheses have the same length.

25. The catheter of claim 22, wherein at least one of the self-expanding prostheses has a length different than at least another of the self-expanding prostheses.

26. The catheter of claim 22, wherein the self-expanding prostheses have ends in engagement with one another prior to deployment.

27. The catheter of claim 22, wherein the self-expanding prostheses are axially connected to each other when in the sheath.

28. The catheter of claim 1, wherein the pusher tube is proximal to the self-expanding prostheses.

29. The catheter of claim 1, wherein the pusher is adapted to engage a prosthesis in the sheath for retrieval thereof, thereby preventing the prosthesis from being deployed.

30. The catheter of claim 1, further comprising an elongate flexible member disposed at least partially under the pusher tube.

31. The catheter of claim 30, wherein the elongate flexible member has a lumen therethrough that is adapted to receive a guidewire.

51. The catheter of claim 30, wherein the one or more prostheses comprise a plurality of self-expanding prostheses.

52. The catheter of claim 51, wherein the self-expanding tubular prostheses have a length in the range of about 2 mm to about 50 mm.

53. The catheter of claim 51, wherein each of the self-expanding prostheses have the same length.

54. The catheter of claim 51, wherein at least one of the self-expanding prostheses has a length different than at least another of the self-expanding prostheses.

55. The catheter of claim 51, wherein the self-expanding prostheses have ends in engagement with one another prior to deployment.

56. The catheter of claim 51, wherein the prostheses are axially connected when in the sheath.

32. A catheter for delivering a prosthesis to a treatment site in a body lumen, the catheter comprising:

a pusher tube having a proximal end and a distal end;

a sheath slidably disposed over the pusher tube and having a distal tip;

one or more self-expanding tubular prostheses carried within the sheath which constrains the prostheses in a radially contracted configuration, the prostheses being independently releasable from the sheath as the sheath is retracted relative to the pusher tube, the prosthesis resiliently expanding upon release from the sheath; and

a radially expandable control member positionable within the prostheses and having an expanded shape which engages an inner surface of at least one of the prostheses to exert an outward force against the at least one prosthesis so as to urge the prosthesis outwardly against the sheath, the control member being axially movable with the sheath so as to slide relative to the prosthesis in engagement therewith as the sheath is retracted relative to the pusher tube,

wherein the distal tip of the sheath is interactive with the control member to enable a prosthesis to be trapped therebetween to inhibit the prosthesis from jumping distally upon expansion, and

wherein the pusher tube is adapted to prevent proximal motion of the one or more self-expanding prostheses as the sheath is retracted.

33. The catheter of claim 32, wherein the distal tip is flared.

34. The catheter of claim 32, wherein the distal tip is expandable as the prostheses expand.

35. The catheter of claim 32, wherein the distal tip has a plurality of axial slits.

36. The catheter of claim 32, wherein the control member urges the prosthesis outwardly against an interior surface of the sheath.

37. The catheter of claim 32, wherein the radially expandable control member comprises a plurality of elongate struts disposed distal to the pusher tube.

38. The catheter of claim 37, wherein the struts are resilient and bend outwardly under compression.

39. The catheter of claim 32, wherein the expandable member is a metal.

40. The catheter of claim 32, wherein the expandable member comprises a basket comprising a plurality of flexible strands.

41. The catheter of claim 40, wherein at least some of the strands are oriented axially and bend outwardly under compression.

42. The catheter of claim 40, wherein the strands are metal.

43. The catheter of claim 40, wherein the strands are a polymer.

44. The catheter of claim 32, wherein the expandable member is a polymer.

45. The catheter of claim 32, wherein the expandable member comprises a balloon.

46. The catheter of claim 32, wherein the self-expanding tubular prostheses carry a therapeutic agent adapted to being released therefrom.

47. The catheter of claim 46, wherein the therapeutic agent comprises an anti-restenosis agent.

48. The catheter of claim 32, wherein the radially expandable control member engages at least two self-expanding prostheses simultaneously.

49. The catheter of claim 32, further comprising a handle near the proximal end of the pusher tube, the handle having a control mechanism adapted to actuate the sheath and the radially expandable control member during deployment of the self-expanding prostheses.

50. The catheter of claim 49, wherein the sheath is adapted to be retracted while the pusher tube remains fixed relative to the handle so as to expose at least one of the self-expanding tubular prostheses for deployment.

57. The catheter of claim 32, wherein the pusher tube is proximal to the self-expanding prostheses.

58. The catheter of claim 57, wherein the pusher is adapted to engage a prosthesis in the sheath for retrieval thereof, thereby preventing the prosthesis from being deployed.

59. The catheter of claim 32, further comprising an elongate flexible member disposed at least partially under the pusher tube.

60. The catheter of claim 60, wherein the elongate flexible member has a lumen therethrough that is adapted to receive a guidewire.

61. A method of delivering a prosthesis to a treatment site in a body lumen, the method comprising:

positioning a delivery catheter at the treatment site, the delivery catheter having one or more self-expanding tubular prostheses thereon and covered by a sheath;

retracting the sheath so as to expose the prosthesis, the prosthesis resiliently expanding radially into contact with a wall of the body lumen;

radially expanding a control member slidably coupled to the delivery catheter;

engaging an interior surface of the prosthesis with the control member as the sheath is retracted, the control member being retracted in conjunction with the sheath and exerting an outward force against the prosthesis to maintain the axial position of the prosthesis relative to the delivery catheter as the prosthesis is released from the sheath; and

releasing the self-expanding tubular prosthesis from the delivery catheter into the body lumen.

62. The method of claim 61, wherein the control member urges the prosthesis outwardly against the sheath.

63. The method of claim 61, wherein releasing the prosthesis comprises collapsing the radially expandable control member so that the radially expandable control member disengages from the inner surface of the prosthesis.

64. The method of claim 61, wherein releasing the prosthesis comprises deflating a balloon.

65. The method of claim 61, wherein the radially expandable control member comprises a plurality of elongate wire-like struts axially oriented and adapted to bend outwardly under compression.

66. The method of claim 61, wherein the radially expandable control member comprises a balloon.

67. The method of claim 61, wherein the delivery catheter carries a plurality of self-expanding tubular prostheses.

68. The method of claim 67, wherein the plurality of self-expanding tubular prostheses are releasably interconnected while disposed on the delivery catheter.

69. The method of claim 68, wherein the prostheses disconnect upon expansion.

70. The method of claim 61, further comprising retracting the control member axially in conjunction with the sheath so as to slide relative to the prosthesis in engagement therewith.

71. The method of claim 61, wherein at least some of the self-expanding tubular prostheses carry a therapeutic agent adapted to being released therefrom.

72. The method of claim 71, wherein the therapeutic agent comprises an anti-restenosis agent.

74. The method of claim 61, wherein at least another self-expanding prosthesis is retained in the sheath after the prosthesis is released.

75. The method of claim 61, wherein a distal end of the sheath radially expands as the self-expanding prostheses expand.

76. The method of claim 75, wherein the distal end of the sheath flares outwardly as the self-expanding prostheses expand.

77. The method of claim 75, wherein the distal end of the sheath is axially split into sections, the sections deflecting outwardly as the self-expanding prostheses expand.

78. The method of claim 75, wherein the distal end of the sheath resiliently returns to a non-expanded shape following release of the desired number of self-expanding prostheses.

79. The method of claim 75, wherein the distal end of the sheath resiliently returns to a non-expanded shape following retraction of the control member into the sheath.

80. The method of claim 75, wherein the distal end of the sheath is radially expanded by an outward force exerted by the control member.

81. The method of claim 75, wherein the distal end of the sheath is radially expanded by an outward force exerted by the self-expanding prostheses.

73. The method of clam 61, wherein engaging the desired number of self-expanding tubular prostheses comprises inflating a balloon.

82. A self-expanding tubular prosthesis comprising:

a plurality of self-expanding tubular rings having a plurality of axial struts and a plurality of connectors coupling adjacent struts together, the axial struts and the connectors forming a substantially zig-zag pattern;

a bridge member coupling adjacent tubular rings together; and

an interlocking tab coupled to a tubular ring on one end of the tubular prosthesis with a flexible connector, the interlocking tab adapted to interlock with an adjacent prosthesis prior to expansion thereof and wherein the flexible connector allows radial flexing of the interlocking tab relative to the tubular prosthesis.

83. The prosthesis of claim 82, wherein the plurality of connectors are substantially U-shaped.

84. The prosthesis of claim 82, wherein the bridge member is sigmoidal shaped.

85. The prosthesis of claim 82, wherein the bridge member is coupled to at least one of the plurality of connectors.

86. The prosthesis of claim 82, wherein a first bridge member on a proximal end of the prosthesis has a first slope and a second bridge member on a distal end of the prosthesis has a second slope opposite of the first slope.

87. The prosthesis of claim 82, wherein the interlocking tab comprises an enlarged head region and a narrower neck region.

88. The prosthesis of claim 87, wherein the enlarged head region comprises an arcuate strut defining a narrow inlet portion and a wider receiving portion, the receiving portion adapted to receive and interlock with an interlocking tab on an adjacent prosthesis.

89. The prosthesis of claim 88, wherein the receiving portion has a surface substantially transverse to a longitudinal axis of the prosthesis, the surface adapted to allow the prosthesis to be pushed in a direction substantially parallel to the longitudinal axis.

90. The prosthesis of claim 82, wherein the interlocking tab comprises a strut defining an aperture for holding a radiopaque marker.

91. The prosthesis of claim 82, further comprising a therapeutic agent carried on the prosthesis and adapted to be released therefrom.

92. The prosthesis of claim 91, wherein the therapeutic agent comprises an anti-restenosis agent.