MULTIPLE INDEPENDENT NESTED STENT STRUCTURES AND METHODS FOR THEIR PREPARATION AND DEPLOYMENT

• US 20090264979A1
• Filed: 06/26/2009
• Published: 10/22/2009
• Est. Priority Date: 01/17/2003
• Status: Active Grant

• Current Assignee: JW Medical Systems Ltd
• Original Assignee: XTENT, Inc.
• Inventors: Andreas, Bernard, Gifford, Hanson S. III, Deem, Mark E., Grainger, Jeffry J., Snow, David W., Kao, Stephen
• Granted Patent: US 8,282,680 B2
• Time in Patent Office: Days
• US Class Current: 623/1.110
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2002/826 more than one stent being applied sequentially
• CPC Class Codes: A61F 2002/828 Means for connecting a plurality of stents allowing flexibility of the whole structure
• CPC Class Codes: A61F 2002/91508 the meander having a difference in amplitude along the band
• CPC Class Codes: A61F 2002/91516 the meander having a change in frequency along the band
• CPC Class Codes: A61F 2002/91525 within the whole structure different bands showing different meander characteristics, e.g. frequency or amplitude
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/9155 Adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/9583 Means for holding the stent on the balloon, e.g. using protrusions, adhesives or an outer sleeve

Abstract

Blood vessels and other body lumens are stented using stent structures comprising a plurality of radially expansible rings where at least some of the rings comprise axially extending elements which interleave with axially extending elements on adjacent unconnected rings. The ring structures may be open cell structures or closed cell structures, and the axially extending elements will typically be formed as part of the open cell or closed cell structure.

Claims

1. A stent structure comprising:

a plurality of radially expansible rings arranged along an axial line, each of the rings having an unexpanded crimped configuration suitable for mounting on a delivery catheter for delivery into a blood vessel and an expanded configuration in which an expanded ring engages a wall of the vessel, wherein at least some of the axially adjacent rings are separable from an adjacent ring and wherein at least some of the axially separable rings comprise axially extending elements which, when the radially expansible rings are in the unexpanded crimped configuration, interleave with axially extending elements on an adjacent separable ring, without interlocking with the adjacent separable ring, none of the axially extending elements constraining axial separation of the adjacent rings in the unexpanded crimped configuration, and wherein at least some of the axially extending elements comprise expansible closed structures which widen as the rings are expanded and wherein at least some of the axially separable rings further comprise spacers which engage the axially extending elements on adjacent rings to provide a preselected spacing between adjacent rings upon radial expansion.

2. A stent structure as in claim 1, wherein the expansible closed structures are selected from the group consisting of boxes, diamonds, rhomboids, ovals, and ellipses.

3. A stent structure as in claim 1, wherein the closed cells are defined by a slot pattern selected from the group consisting of I-patterns, H-patterns, and J-patterns.

4. A stent structure as in claim 1, wherein the axially separable rings are configured to axially shorten upon expansion.

5. A stent structure as in claim 1, wherein the axially extending elements remain interleaved following expansion.

6. A stent structure as in claim 1, wherein the axially extending elements axially interleave over a distance of at least 0.1 mm prior to stent expansion.

7. A stent structure as in claim 6, wherein the distance is in the range from 1 mm to 5 mm.

8. A stent structure as in claim 1, wherein the rings have axial lengths in range from 1 mm to 10 mm, prior to radial expansion.

9. A stent structure as in claim 1, consisting of from two to 50 expansible ring structures.

10. A stent structure as in claim 1, wherein the radially expansible rings releasably carry a biologically active agent.

11. A stent structure as in claim 10, wherein the biologically active agent inhibits hyperplasia.

12. A stent structure as in claim 11, wherein the biologically active agent is selected from the group consisting of anti-neoplastic drugs, including paclitaxel, methotrexate, and batimastal;

antibiotics including doxycycline, tetracycline, rapamycin, and actinomycin;

immunosuppressants including dexamethasone, and methyl prednisolone;

nitric oxide sources including nitroprussides;

estrogen; and

estradiols.

69. A stent structure as in claim 1, wherein the axially extending elements have an overlapping portion which is received between axially extending elements of an adjacent ring, the overlapping portion comprising a pair of axial struts separated by a circumferential distance which is constant or tapering toward the adjacent ring throughout all of the overlapping portion.

70. A stent structure as in claim 69, wherein adjacent axially extending elements form a concave region therebetween having a closed end, the spacers maintaining a gap between the closed end and an axially extending element of the adjacent ring.

71. A stent structure as in claim 70, wherein the spacer comprises a cradle structure adapted to receive an axially extending element on an adjacent ring.

72. A stent structure as in claim 70, wherein the spacer comprises a concave abutment.

73. A stent structure as in claim 70, wherein the spacer comprises an axially extending strut having an axial extension length, the axially extending strut disposed between two adjacent axially extending elements on the same ring, the two adjacent axially extending elements having an axial length greater than the axial extension length of the strut.

13. A stent deployment system comprising:

an elongated carrier having a central axis;

a plurality of radially expansible rings expandable into an expanded configuration in which an expanded ring engages a blood vessel wall, the rings arranged over a surface of the elongated carrier in an unexpanded crimped configuration suitable for delivery into the blood vessel, wherein at least some of the radially expansible rings are separable from an adjacent ring and comprise axially extending elements which, when the rings are in the unexpanded crimped configuration, interleave with axially extending elements on an adjacent unconnected ring without interlocking with the adjacent radially expansible ring, none of the axially extending elements constraining axial separation of the adjacent rings in the unexpanded crimped configuration, and wherein at least some of the axially extending elements comprise expansible closed structures which widen as the rings are expanded and wherein at least some of the axially separable rings further comprise spacers which engage the axially extending elements on adjacent rings to provide a preselected spacing between adjacent rings upon radial expansion.

14. A stent deployment system as in claim 13, wherein the elongated carrier comprises a radially expansible balloon having an outer surface, wherein the radially expansible rings are disposed over the outer surface of the balloon.

15. A stent deployment system as in claim 14, wherein the balloon consists of a single inflation chamber.

16. A stent deployment system as in claim 14, wherein the balloon comprises a plurality of independent chambers wherein individual expansible rings are disposed over single independently inflatable chambers.

17. A stent deployment system as in claim 13, wherein the elongated carrier comprises a carrier tube having an inner surface which constrains the radially expansible rings.

18. A stent deployment system as in claim 17, further comprising a pusher tube arranged to axially advance the radially expansible rings from the carrier tube.

19. A stent deployment system as in claim 18, wherein the radially expansible rings are resilient and radially constrained so that they expand when advanced distally from the carrier tube.

20. A stent deployment system as in claim 13, wherein the radially expansible rings are deformable, said structure further comprising a balloon arranged to expand individual rings as said rings are advanced from the carrier tube.

21. A stent deployment system as in claim 13, wherein the expansible closed structures are selected from the group consisting of boxes, rhomboids, ovals, ellipses, diamonds, and irregular polygons.

22. A stent deployment system as in claim 13, wherein the closed cells are defined by a slot pattern selected from the group consisting of I-patterns and H-patterns.

23. A stent deployment structure as in claim 13, wherein the radially expansible rings are configured to axially shorten upon expansion.

24. A stent deployment structure as in claim 13, wherein the axially extending elements remain interleaved following expansion.

25. A stent deployment structure as in claim 13, wherein the axially extending elements axially interleave over a distance of at least 0.1 mm prior to stent expansion.

26. A stent deployment structure as in claim 25, wherein the distance is in the range from 1 mm to 5 mm.

27. A stent deployment system as in claim 13, wherein the rings have axial lengths in range from 1 mm to 10 mm, prior to radial expansion.

28. A stent deployment system as in claim 27, consisting of from two to 50 expansible ring structures.

29. A stent deployment system as in claim 13, wherein the radially expansible rings releasably carry a biologically active agent.

30. A stent deployment system as in claim 29, wherein the biologically active agent inhibits hyperplasia.

31. A stent deployment system as in claim 30, wherein the biologically active agent is selected from the group consisting of anti-neoplastic drugs including paclitaxel, methotrexate, and batimastal;

antibiotics including doxycycline, tetracycline, rapamycin, and actinomycin;

immunosuppressants including dexamethasone and methyl prednisolone;

nitric oxide sources including nitroprussides;

estrogen; and

estradiols.

47. A stent deployment system as in claim 14, wherein the rings are axially slidable over the outer surface of the balloon.

48. A stent deployment system as in claim 13, wherein the elongated carrier is adapted to axially separate the adjacent unconnected rings in the unexpanded configuration.

49. A stent deployment system as in claim 48, wherein the elongated carrier comprises a valve member adapted to engage at least one ring to separate the at least one ring from an adjacent unconnected ring.

74. A stent structure as in claim 13, wherein the axially extending elements have an overlapping portion which is received between axially extending elements of an adjacent ring, the overlapping portion comprising a pair of axial struts separated by a circumferential distance which is constant or tapering toward the adjacent ring throughout all of the overlapping portion.

75. A stent structure as in claim 74, wherein adjacent axially extending elements form a concave region therebetween having a closed end, the spacers maintaining a gap between the closed end and an axially extending element of the adjacent ring.

76. A stent structure as in claim 75, wherein the spacer comprises a cradle structure adapted to receive an axially extending element on an adjacent ring.

77. A stent structure as in claim 75, wherein the spacer comprises a concave abutment.

78. A stent structure as in claim 75, wherein the spacer comprises an axially extending strut having an axial extension length, the axially extending strut disposed between two adjacent axially extending elements on the same ring, the two adjacent axially extending elements having an axial length greater than the axial extension length of the strut.

32. A method for arranging multiple independent stent rings on a carrier of a catheter, said method comprising:

providing an elongated carrier structure;

mounting a plurality of radially expansible rings comprising axially extending elements on the carrier structure with the rings in an unexpanded crimped configuration suitable for delivery into a blood vessel and at least some of the rings are separable from an adjacent ring, wherein the axially extending elements on adjacent rings interleave when mounted on the carrier structure in the unexpanded crimped configuration without interlocking so as to permit axial separation of the adjacent rings, none of the axially extending elements constraining axial separation of the adjacent rings in the unexpanded crimped configuration, and wherein at least some of the axially extending elements comprise expansible closed structures which widen as the rings are expanded and wherein at least some of the axially separable rings further comprise spacers which engage the axially extending elements on adjacent rings to provide a preselected spacing between adjacent rings upon radial expansion.

33. A method as in claim 32, wherein the number of rings mounted on the carrier structure is selected to provide a desired overall stent length.

34. A method as in claim 33, wherein the number of rings is from two to 50 and the overall stent length is in the range from 2 mm to 200 mm.

35. A method as in claim 32, wherein the expansible closed structures are selected from the group consisting of boxes, rhomboids, ovals, ellipses, diamonds, and irregular polygons.

36. A method as in claim 32, wherein the expansible closed structures are defined by a slot pattern selected from the group consisting of I-patterns and H-patterns, and J-patterns.

37. A method as in claim 32, wherein the radially expansible rings are configured to axially shorten upon expansion.

38. A method as in claim 32, wherein the axially extending elements remain interleaved following expansion.

39. A method as in claim 32, wherein the axially extending elements axially interleave over a distance of at least 0.1 mm prior to stent expansion.

40. A method as in claim 39, wherein the distance is in the range from 1 mm to 5 mm.

41. A method as in claim 32, wherein the rings have axial lengths in range from 1 mm to 10 mm, prior to radial expansion.

42. A method as in claim 41, wherein the rings have axial lengths in the range from 0.9 mm to 9 mm after radial expansion.

43. A method as in claim 42, consisting of from two to 50 expansible ring structures.

44. A method as in claim 32, wherein the radially expansible rings releasably carry a biologically active agent.

45. A method as in claim 44, wherein the biologically active agent inhibits hyperplasia.

46. A method as in claim 45, wherein the biologically active agent is selected from the group consisting of anti-neoplastic drugs including paclitaxel, methotrexate and batimastal;

antibiotics including doxycycline, tetracycline, rapamycin, and actinomycin;

immunosuppressants including dexamethasone and methyl prednisolone;

nitric oxide sources including nitroprussides;

estrogen; and

estradiols.

50. A method as in claim 32, further comprising covering at least a portion of the rings with a carrier tube coupled to the carrier structure.

51. A method as in claim 32, wherein the rings are mounted on an elongated balloon coupled to the carrier structure.

52. A method as in claim 51, wherein the rings are axially slidable on the elongated balloon.

79. A stent structure as in claim 32, wherein the axially extending elements have an overlapping portion which is received between axially extending elements of an adjacent ring, the overlapping portion comprising a pair of axial struts separated by a circumferential distance which is constant or tapering toward the adjacent ring throughout all of the overlapping portion.

80. A stent structure as in claim 79, wherein adjacent axially extending elements form a concave region therebetween having a closed end, the spacers maintaining a gap between the closed end and an axially extending element of the adjacent ring.

81. A stent structure as in claim 80, wherein the spacer comprises a cradle structure adapted to receive an axially extending element on an adjacent ring.

82. A stent structure as in claim 80, wherein the spacer comprises a concave abutment.

83. A stent structure as in claim 80, wherein the spacer comprises an axially extending strut having an axial extension length, the axially extending strut disposed between two adjacent axially extending elements on the same ring, the two adjacent axially extending elements having an axial length greater than the axial extension length of the strut.

53. A stent structure comprising:

a plurality of radially expansible rings arranged along an axial line and uncovered by material extending between adjacent rings, each of the rings having an unexpanded crimped configuration suitable for mounting on a delivery catheter for delivery into a blood vessel and an expanded configuration in which an expanded ring engages a wall of the vessel, wherein at least some of the axially adjacent rings are separable from an adjacent ring and wherein at least some of the axially separable rings comprise axially extending elements which, when the radially expansible rings are in the unexpanded crimped configuration, interleave with axially extending elements on an adjacent separable ring without interlocking with the adjacent separable ring, none of the axially extending elements constraining axial separation of the adjacent rings in the unexpanded crimped configuration, thereby allowing each of the separable rings to be expanded without expanding an adjacent unconnected ring.

54. A stent structure as in claim 53, wherein at least some of the axially extending elements comprise expansible closed structures which widen as the rings are expanded.

55. A stent structure as in claim 54, wherein the expansible closed structures are selected from the group consisting of boxes, diamonds, rhomboids, ovals, and ellipses.

56. A stent structure as in claim 54, wherein the closed cells are defined by a slot pattern selected from the group consisting of I-patterns, H-patterns, and J-patterns.

57. A stent structure as in claim 53, wherein at least some of the axially extending elements comprise expansible open structures.

58. A stent structure as in claim 57, wherein the expansible open structures are selected from the group consisting of serpentine structures, zigzag structures, and castellated structures.

59. A stent structure as in claim 53, wherein at least some of the axially unconnected rings further comprise spacers which engage the axially extending elements on adjacent rings to provide a preselected spacing between adjacent rings upon radial expansion.

60. A stent structure as in claim 53, wherein the axially separable rings are configured to axially shorten upon expansion.

61. A stent structure as in claim 53, wherein the axially extending elements remain interleaved following expansion.

62. A stent structure as in claim 53, wherein the axially extending elements axially interleave over a distance of at least 0.1 mm prior to stent expansion.

63. A stent structure as in claim 62, wherein the distance is in the range from 1 mm to 5 mm.

64. A stent structure as in claim 53, wherein the rings have axial lengths in range from 1 mm to 10 mm, prior to radial expansion.

65. A stent structure as in claim 53, consisting of from two to 50 expansible ring structures.

66. A stent structure as in claim 53, wherein the radially expansible rings releasably carry a biologically active agent.

67. A stent structure as in claim 66, wherein the biologically active agent inhibits hyperplasia.

68. A stent structure as in claim 67, wherein the biologically active agent is selected from the group consisting of anti-neoplastic drugs, including paclitaxel, methotrexate, and batimastal;

antibiotics including doxycycline, tetracycline, rapamycin, and actinomycin;

immunosuppressants including dexamethasone, and methyl prednisolone;

nitric oxide sources including nitroprussides;

estrogen; and

estradiols.

84. A stent structure as in claim 59, wherein the axially extending elements have an overlapping portion which is received between axially extending elements of an adjacent ring, the overlapping portion comprising a pair of axial struts separated by a circumferential distance which is constant or tapering toward the adjacent ring throughout all of the overlapping portion.

85. A stent structure as in claim 84, wherein adjacent axially extending elements form a concave region therebetween having a closed end, the spacers maintaining a gap between the closed end and an axially extending element of the adjacent ring.

86. A stent structure as in claim 85, wherein the spacer comprises a cradle structure adapted to receive an axially extending element on an adjacent ring.

87. A stent structure as in claim 85, wherein the spacer comprises a concave abutment.

88. A stent structure as in claim 85, wherein the spacer comprises an axially extending strut having an axial extension length, the axially extending strut disposed between two adjacent axially extending elements on the same ring, the two adjacent axially extending elements having an axial length greater than the axial extension length of the strut.