Longitudinally flexible expandable stent

• US 6,348,065 B1
• Filed: 07/24/1998
• Issued: 02/19/2002
• Est. Priority Date: 03/01/1995
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Brown, Brian J., Davis, Michael L.
• Primary Examiner(s): Prebilic, Paul B.
• Application Number:
  US09/122,431
• Time in Patent Office: 1,306 Days
• Field of Search: 623/1.15, 623/1.16, 623/1.17, 623/1.18, 623/1.19, 606/195, 606/198
• US Class Current: 623/1.16
• 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 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 2002/91541 Adjacent bands are arranged out of phase
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2210/0019 operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61F 2250/0018 differing in elasticity, stiffness or compressibility

Abstract

The invention provides a tubular expandable stent including a plurality of cylindrically shaped open cylindrical segments aligned on a common longitudinal axis to define a generally tubular stent body, each segment being defined by a member formed in an undulating flexible pattern of interconnected substantially parallel struts with pairs thereof having alternating interconnecting end portions to define the periphery of the expandable stent segment, and in which the connected end portions of paired struts in each segment, before the stent is expanded, are positioned substantially opposite to connected end portions of paired struts in adjacent segments.

Claims

1. A tubular, flexible, self-expandable stent comprising:

1) a plurality of cylindrically shaped segments which are interconnected,

one of the cylindrically shaped segments being an intermediate cylindrically shaped segment having a proximal end and a distal end,

one of the cylindrically shaped segments being a proximal cylindrically shaped segment having a proximal end and a distal end located adjacent the proximal end of the intermediate cylindrically shaped segment and

one of the cylindrically shaped segments being a distal cylindrically shaped segment having a distal end and a proximal end located adjacent the distal end of the intermediate cylindrically shaped segment,

each cylindrically shaped segment being defined by an undulating pattern of interconnected struts, each strut having a proximal end and a distal end, each strut adjacent a first strut and a second strut, the strut and the first strut interconnected only at their distal ends, the strut and the second strut interconnected only at their proximal ends, and

2) a plurality of interconnecting elements including proximal interconnecting elements and distal interconnecting elements, each interconnecting element having a proximal end and a distal end, the proximal end of the interconnecting element circumferentially and longitudinally offset from the distal end of the interconnecting element, the interconnecting elements shorter in length than the cylindrically shaped segments,

each proximal interconnecting element extending proximally from an interconnected proximal end of adjacent struts on the intermediate cylindrically shaped segment to an interconnected distal end of adjacent struts on the proximal cylindrically shaped segment,

each distal interconnecting element extending distally from an interconnected distal end of adjacent struts on the intermediate cylindrically shaped segment to an interconnected proximal end of adjacent struts on the distal cylindrically shaped segment,

the interconnecting elements extending at an oblique angle relative to the longitudinal axis, a minimum length pathway of at least three interconnected circumferentially adjacent struts on the intermediate cylindrically shaped segment extending between the distal ends of the proximal interconnecting elements and the proximal ends of the distal interconnecting elements,

wherein flexing of the stent occurs substantially in the cylindrically shaped segments.

2. The stent of claim 1 formed of a shape memory metal.

3. The stent of claim 2 formed of nitinol.

4. The stent of claim 1 wherein each interconnecting element extends from a side of an interconnected end of adjacent struts on one cylindrically shaped segment to a side of an interconnected end of adjacent struts on an adjacent cylindrically shaped segment.

5. The stent of claim 1 wherein circumferentially adjacent interconnecting elements are separated by six struts.

6. The stent of claim 1 wherein there are at least three interconnecting elements extending between any two adjacent cylindrically shaped segments.

7. The stent of claim 1 constructed and arranged such that upon expansion of the stent, connected ends of adjacent struts in the proximal cylindrically shaped segment are circumferentially displaced relative to connected ends of adjacent struts in the intermediate cylindrically shaped segment and connected ends of adjacent struts in the intermediate cylindrically shaped segment are circumferentially displaced relative to connected ends of adjacent struts in the distal cylindrically shaped segment to accommodate longitudinal flexing of the stent within the cylindrically shaped segments and without interference between adjacent cylindrically shaped segments.

15. The stent of claim 1 wherein the direction of the interconnecting elements reverses between adjacent pairs of interconnected cylindrically shaped segments.

40. The stent of claim 1 wherein in interconnecting elements are of a shorter length than the struts.

8. A tubular, flexible, self-expandable stent made of nitinol, the stent comprising:

1) a plurality of cylindrically shaped segments which are interconnected,

one of the cylindrically shaped segments being an intermediate cylindrically shaped segment having a proximal end and a distal end,

one of the cylindrically shaped segments being a proximal cylindrically shaped segment having a proximal end and a distal end located adjacent the proximal end of the intermediate cylindrically shaped segment and

one of the cylindrically shaped segments being a distal cylindrically shaped segment having a distal end and a proximal end located adjacent the distal end of the intermediate cylindrically shaped segment,

each cylindrically shaped segment being defined by an undulating pattern of interconnected struts, each strut having a proximal end and a distal end, each strut adjacent a first strut and a second strut, the strut and the first strut interconnected only at their distal ends, the strut and the second strut interconnected only at their proximal ends, and

2) a plurality of interconnecting elements including proximal interconnecting elements and distal interconnecting elements, each interconnecting element having a proximal end and a distal end, the proximal end of the interconnecting element circumferentially and longitudinally offset from the distal end of the interconnecting element, the interconnecting elements shorter in length than the cylindrically shaped segments,

each proximal interconnecting element extending proximally from an interconnected proximal end of adjacent struts on the intermediate cylindrically shaped segment to an interconnected distal end of adjacent struts on the proximal cylindrically shaped segment,

each distal interconnecting element extending distally from an interconnected distal end of adjacent struts on the intermediate cylindrically shaped segment to an interconnected proximal end of adjacent struts on the distal cylindrically shaped segment,

a minimum length pathway of at least three interconnected circumferentially adjacent struts on the intermediate cylindrically shaped segment extending between the distal ends of the proximal interconnecting elements and the proximal ends of the distal interconnecting elements,

wherein upon expansion of the stent interconnected ends of adjacent struts in the proximal cylindrically shaped segment are circumferentially displaced relative to interconnected ends of adjacent struts in the intermediate cylindrically shaped segment and interconnected ends of adjacent struts in the intermediate cylindrically shaped segment are circumferentially displaced relative to interconnected ends of adjacent struts in the distal cylindrically shaped segment to accommodate longitudinal flexing of the stent substantially within the cylindrically shaped segments without substantial flexing of the interconnecting elements and without interference between adjacent cylindrically shaped segments.

9. The stent of claim 8 wherein each interconnecting element extends from a side of an interconnected end of adjacent struts on one cylindrically shaped segment to a side of an interconnected end of adjacent struts on an adjacent cylindrically shaped segment.

10. The stent of claim 8 wherein circumferentially adjacent interconnecting elements are separated by six struts.

11. The stent of claim 8 wherein there are at least three interconnecting elements extending between any two adjacent cylindrically shaped segments.

16. The stent of claim 8 wherein the direction of the interconnecting elements reverses between adjacent pairs of interconnected cylindrically shaped segments.

12. A tubular, flexible, self-expandable stent comprising:

1) a plurality of cylindrically shaped segments which are interconnected,

one of the cylindrically shaped segments being an intermediate cylindrically shaped segment having a proximal end and a distal end,

one of the cylindrically shaped segments being a proximal cylindrically shaped segment having a proximal end and a distal end located adjacent the proximal end of the intermediate cylindrically shaped segment and

one of the cylindrically shaped segments being a distal cylindrically shaped segment having a distal end and a proximal end located adjacent the distal end of the intermediate cylindrically shaped segment,

each cylindrically shaped segment being defined by an undulating pattern of interconnected struts, each strut having a proximal end and a distal end, each strut adjacent a first strut and a second strut, the strut and the first strut interconnected only at their distal ends, the strut and the second strut interconnected only at their proximal ends, and

2) a plurality of interconnecting elements including proximal interconnecting elements and distal interconnecting elements, each interconnecting element having a proximal end and a distal end, the proximal end of the interconnecting element circumferentially and longitudinally offset from the distal end of the interconnecting element, the interconnecting elements shorter in length than the cylindrically shaped segments,

each proximal interconnecting element extending proximally from an interconnected proximal end of adjacent struts on the intermediate cylindrically shaped segment to an interconnected distal end of adjacent struts on the proximal cylindrically shaped segment,

each distal interconnecting element extending distally from an interconnected distal end of adjacent struts on the intermediate cylindrically shaped segment to an interconnected proximal end of adjacent struts on the distal cylindrically shaped segment,

the interconnecting elements extending at an oblique angle relative to the longitudinal axis, a minimum length pathway of at least three interconnected circumferentially adjacent struts on the intermediate cylindrically shaped segment extending between the distal ends of the proximal interconnecting elements and the proximal ends of the distal interconnecting elements, at least three interconnecting elements extending between any two adjacent cylindrically shaped segments,

wherein upon expansion of the stent interconnected ends of adjacent struts in the proximal cylindrically shaped segment are displaced circumferentially relative to interconnected ends of adjacent struts in the intermediate cylindrically shaped segment and interconnected ends of adjacent struts in the intermediate cylindrically shaped segment are circumferentially displaced relative to interconnected ends of adjacent struts in the distal cylindrically shaped segment to accommodate longitudinal flexing of the stent substantially within the cylindrically shaped segments and without interference between adjacent cylindrically shaped segments.

13. The stent of claim 12 wherein the direction of the interconnecting elements reverses between adjacent pairs of interconnected segments.

14. The stent of claim 12 wherein circumferentially adjacent interconnecting elements are separated by six struts.

17. A tubular, flexible, self-expandable stent comprising:

1) a plurality of cylindrically shaped segments which are interconnected including

a first cylindrically shaped segment defined by an undulating pattern of interconnected first struts, each first strut having a proximal end and a distal end, first struts which are circumferentially adjacent one another and connected at the proximal ends of the first struts forming first troughs, first struts which are circumferentially adjacent one another and connected at the distal ends of the first struts forming first peaks, the first troughs and the first peaks alternating with one another and circumferentially offset from one another about the first cylindrically shaped segment,

a second cylindrically shaped segment defined by an undulating pattern of interconnected second struts, each second strut having a proximal end and a distal end, second struts which are circumferentially adjacent one another and connected at the proximal ends of the second struts forming second troughs, second struts which are circumferentially adjacent one another and connected at the distal ends of the second struts forming second peaks, the second troughs and the second peaks alternating with one another and circumferentially offset from one another about the second cylindrically shaped segment,

a third cylindrically shaped segment defined by an undulating pattern of interconnected third struts, each third strut having a proximal end and a distal end, third struts which are circumferentially adjacent one another and connected at the proximal ends of the third struts forming third troughs, third struts which are circumferentially adjacent one another and connected at the distal ends of the third struts forming third peaks, the third troughs and the third peaks alternating with one another and circumferentially offset from one another about the third cylindrically shaped segment, and

2) a plurality of first connectors connecting the first cylindrically shaped segment and the second cylindrically shaped segment, each first connector having a first end and a second end circumferentially and longitudinally offset from the first end, each first connector extending from one of the first peaks to one of the second troughs, each first connector extending at an oblique angle relative to the longitudinal axis, first connectors which are adjacent one another separated by six first struts, the first connectors shorter in length than the first and second cylindrically shaped segments,

a plurality of second connectors connecting the second cylindrically shaped segment and the third cylindrically shaped segment, each second connector having a first end and a second end circumferentially and longitudinally offset from the first end, each second connector extending from one of the second peaks to one of the third troughs, each second connector extending at an oblique angle relative to the longitudinal axis, second connectors which are adjacent one another separated by six second struts, the second connectors shorter in length than the second and third cylindrically shaped segments,

the second end of each first connector separated from the first end of a second connector which is nearest to it by at least three second struts,

whereby flexing of the stent occurs substantially in the cylindrically shaped segments.

18. The stent of claim 17 formed of a shape memory metal.

19. The stent of claim 18 formed of nitinol.

20. The stent of claim 17, each first peak having a first side, a second side and a middle portion between the first and second sides, each second trough having a first side, a second side and a middle portion between the first and second sides, each second peak having a first side, a second side and a middle portion between the first and second sides, and each third trough having a first side, a second side and a middle portion between the first and second sides,

wherein each first connector extends from the first side of one of the first peaks to the second side of one of the second troughs and each second connector extends from the first side of one of the second peaks to the second side of one of the third troughs.

21. The stent of claim 17, each first connector having a longitudinal axis and each second connector having a longitudinal axis, the longitudinal axis of each first connector intersecting the longitudinal axis of the second connector nearest to the first connector at an angle, the angle bisected by an imaginary line parallel to the longitudinal axis of the stent.

22. The stent of claim 17 wherein there are at least three first connectors and at least three second connectors.

23. The stent of claim 17 constructed and arranged such that upon expansion of the stent, the first peaks are circumferentially displaced relative to the second troughs and the second peaks are circumferentially displaced relative to the third troughs to accommodate longitudinal flexing of the stent within the cylindrically shaped segments and without interference between adjacent cylindrically shaped segments.

24. The stent of claim 17 wherein the direction of the second connectors is reversed relative to the direction of the first connectors.

25. The stent of claim 17 wherein the first cylindrically shaped segment has a first amplitude characterized by the longitudinal distance between the first peaks and the first troughs and the second cylindrically shaped segment has a second amplitude characterized by the longitudinal distance between the second peaks and the second troughs, the first amplitude different from the second amplitude.

26. The stent of claim 17 wherein the first connectors are longer than the second connectors.

41. The stent of claim 17 wherein the first connectors are shorter than the second connectors.

27. A stent having a proximal end and a distal end and a longitudinal axis, the stent comprising:

1) a plurality of undulating cylindrical segments including

a first undulating cylindrical segment comprising a plurality of alternating first peaks and first troughs, the first peaks pointing toward the distal end of the stent, the first troughs pointing toward the proximal end of the stent;

a second undulating cylindrical segment comprising a plurality of alternating second peaks and second troughs, the second peaks pointing toward the distal end of the stent, the second troughs pointing toward the proximal end of the stent;

a third undulating cylindrical segment comprising a plurality of alternating third peaks and third troughs, the third peaks pointing toward the distal end of the stent, the third troughs pointing toward the proximal end of the stent;

2) a plurality of connectors including

a plurality of first connectors connecting the first undulating cylindrical segment and the second undulating cylindrical segment, each first connector having a proximal end and a distal end circumferentially and longitudinally displaced from the proximal end, the proximal end extending from one of the first peaks, the distal end extending from one of the second troughs, the first connectors extending from every third first peak and every third second trough, the first connectors shorter in length than the first undulating cylindrical segment and the second undulating cylindrical segment,

a plurality of second connectors connecting the second undulating cylindrical segment and the third undulating cylindrical segment, each second connector having a proximal end and a distal end circumferentially and longitudinally displaced from the proximal end, the proximal end extending from one of the second peaks, the distal end extending from one of the third troughs, the second connectors extending from every third second peak and every third third trough, the second connectors shorter in length than the second undulating cylindrical segment and the third undulating cylindrical segment, each first connector separated from a second connector which is nearest to it by at least one second peak and one second trough,

wherein flexing of the stent occurs substantially in the undulating cylindrical segments.

28. The stent of claim 27 formed of a shape memory metal.

29. The stent of claim 28 formed of nitinol.

30. The stent of claim 27 wherein there are at least three first connectors connecting the first and second undulating cylindrical segments.

31. The stent of claim 27 constructed and arranged such that upon expansion of the stent, peaks of undulating cylindrical segments are circumferentially displaced relative to troughs of adjacent undulating cylindrical segments to accommodate longitudinal flexing of the stent within the cylindrically shaped segments and without interference between adjacent cylindrically shaped segments.

32. The stent of claim 31 wherein the connectors are substantially linear.

33. The stent of claim 32 wherein the connectors extend diagonally relative to the longitudinal axis of the stent.

34. The stent of claim 27 each first peak having a first side, a second side and a middle portion between the first and second sides, each second trough having a first side, a second side and a middle portion between the first and second sides, each second peak having a first side, a second side and a middle portion between the first and second sides, and each third trough having a first side, a second side and a middle portion between the first and second sides,

wherein each first connector extends from the first side of one of the first peaks to the second side of one of the second troughs and each second connector extends from the first side of one of the second peaks to the second side of one of the third troughs.

35. The stent of claim 27, each first connector having a longitudinal axis and each second connector having a longitudinal axis, the longitudinal axis of each first connector intersecting the longitudinal axis of the second connector nearest to the first connector at an angle, the angle bisected by an imaginary line parallel to the longitudinal axis of the stent.

36. The stent of claim 27 wherein the direction of the second connectors is reversed relative to the direction of the first connectors.

37. The stent of claim 27 wherein the first undulating cylindrical segment has a first amplitude characterized by the longitudinal distance between the first peaks and the first troughs and the second undulating cylindrical segment has a second amplitude characterized by the longitudinal distance between the second peaks and the second troughs, the first amplitude different from the second amplitude.

38. The stent of claim 27 wherein the first connectors are characterized by a first length and the second connectors are characterized by a second length, the first length different from the second length.

39. A stent having a proximal end and a distal end, the stent comprising:

1) a plurality of undulating cylindrical segments including

a first undulating cylindrical segment comprising a plurality of alternating first peaks and first troughs, the first peaks pointing toward the distal end of the stent, the first troughs pointing toward the proximal end of the stent;

a second undulating cylindrical segment comprising a plurality of alternating second peaks and second troughs, the second peaks pointing toward the distal end of the stent, the second troughs pointing toward the proximal end of the stent;

a third undulating cylindrical segment comprising a plurality of alternating third peaks and third troughs, the third peaks pointing toward the distal end of the stent, the third troughs pointing toward the proximal end of the stent; and

2) a plurality of connectors including

a plurality of first connectors connecting the first undulating cylindrical segment and the second undulating cylindrical segment, each first connector having a proximal end and a distal end circumferentially and longitudinally displaced from the proximal end, the proximal end extending from one of the first peaks, the distal end extending from one of the second troughs, the first connectors extending from every third first peak and every third second trough, the first connectors shorter in length than the first undulating cylindrical segment and the second undulating cylindrical segment,

a plurality of second connectors connecting the second undulating cylindrical segment and the third undulating cylindrical segment, each second connector having a proximal end and a distal end circumferentially and longitudinally displaced from the proximal end, the proximal end extending from one of the second peaks, the distal end extending from one of the third troughs, the second connectors extending from every third second peak and every third third trough, the second connectors shorter in length than the second undulating cylindrical segment and the third undulating cylindrical segment,

each first connector separated from a second connector which is nearest to it by at least one second peak and one second trough,

wherein upon expansion of the stent the first peaks are circumferentially displaced relative to the second troughs and the second peaks are circumferentially displaced relative to the third troughs to accommodate longitudinal flexing of the stent substantially within the undulating cylindrical segments without substantial flexing of the connectors, without interference between the first and second undulating cylindrical segments and without interference between the second and third undulating cylindrical segments.

42. A stent comprising:

1) a plurality of cylindrically shaped segments which are interconnected,

one of the cylindrically shaped segments being an intermediate cylindrically shaped segment having a proximal end and a distal end,

one of the cylindrically shaped segments being a proximal cylindrically shaped segment having a proximal end and a distal end located adjacent the proximal end of the intermediate cylindrically shaped segment and

one of the cylindrically shaped segments being a distal cylindrically shaped segment having a distal end and a proximal end located adjacent the distal end of the intermediate cylindrically shaped segment,

each cylindrically shaped segment being defined by an undulating pattern of interconnected struts, each strut having a proximal end and a distal end, each strut adjacent a first strut and a second strut, the strut and the first strut interconnected only at their distal ends, the strut and the second strut interconnected only at their proximal ends, and

2) a plurality of interconnecting elements including proximal interconnecting elements and distal interconnecting elements, each interconnecting element having a proximal end and a distal end, the proximal end of the interconnecting element circumferentially and longitudinally offset from the distal end of the interconnecting element, the interconnecting elements shorter in length than the cylindrically shaped segments,

each proximal interconnecting element extending proximally from an interconnected proximal end of adjacent struts on the intermediate cylindrically shaped segment to an interconnected distal end of adjacent struts on the proximal cylindrically shaped segment,

each distal interconnecting element extending distally from an interconnected distal end of adjacent struts on the intermediate cylindrically shaped segment to an interconnected proximal end of adjacent struts on the distal cylindrically shaped segment,

the interconnecting elements non-parallel to the longitudinal axis, a minimum length pathway of at least three interconnected circumferentially adjacent struts on the intermediate cylindrically shaped segment extending between the distal ends of the proximal interconnecting elements and the proximal ends of the distal interconnecting elements,

wherein flexing of the stent occurs substantially in the cylindrically shaped segments.

43. The stent of claim 42 wherein circumferentially adjacent interconnecting elements are separated by six struts.

44. A stent comprising:

1) a plurality of cylindrically shaped segments which are interconnected,

one of the cylindrically shaped segments being an intermediate cylindrically shaped segment having a proximal end and a distal end,

one of the cylindrically shaped segments being a proximal cylindrically shaped segment having a proximal end and a distal end located adjacent the proximal end of the intermediate cylindrically shaped segment and

one of the cylindrically shaped segments being a distal cylindrically shaped segment having a distal end and a proximal end located adjacent the distal end of the intermediate cylindrically shaped segment,

each cylindrically shaped segment being defined by an undulating pattern of interconnected struts, each strut having a proximal end and a distal end, each strut adjacent a first strut and a second strut, the strut and the first strut interconnected only at their distal ends, the strut and the second strut interconnected only at their proximal ends, and

2) a plurality of interconnecting elements including proximal interconnecting elements and distal interconnecting elements, each interconnecting element having a proximal end and a distal end, the proximal end of the interconnecting element circumferentially and longitudinally offset from the distal end of the interconnecting element, the interconnecting elements shorter in length than the cylindrically shaped segments,

each proximal interconnecting element extending proximally from an interconnected proximal end of adjacent struts on the intermediate cylindrically shaped segment to an interconnected distal end of adjacent struts on the proximal cylindrically shaped segment,

each distal interconnecting element extending distally from an interconnected distal end of adjacent struts on the intermediate cylindrically shaped segment to an interconnected proximal end of adjacent struts on the distal cylindrically shaped segment,

the interconnecting elements non-parallel to the longitudinal axis, a minimum length pathway of at least three interconnected circumferentially adjacent struts on the intermediate cylindrically shaped segment extending between the distal ends of the proximal interconnecting elements and the proximal ends of the distal interconnecting elements, at least three interconnecting elements extending between any two adjacent cylindrically shaped segments,

wherein upon expansion of the stent interconnected ends of adjacent struts in the proximal cylindrically shaped segment are displaced circumferentially relative to interconnected ends of adjacent struts in the intermediate cylindrically shaped segment and interconnected ends of adjacent struts in the intermediate cylindrically shaped segment are circumferentially displaced relative to interconnected ends of adjacent struts in the distal cylindrically shaped segment to accommodate longitudinal flexing of the stent substantially within the cylindrically shaped segments and without interference between adjacent cylindrically shaped segments.

45. The stent of claim 44 wherein circumferentially adjacent interconnecting elements are separated by six struts.