Flexible expandable stent

• US 5,733,303 A
• Filed: 05/31/1995
• Issued: 03/31/1998
• Est. Priority Date: 03/17/1994
• Status: Expired due to Term

• Current Assignee: Medinol Limited (Medinol USA Incorporated)
• Original Assignee: Medinol Limited (Medinol USA Incorporated)
• Inventors: Pinchasik, Gregory, Israel, Henry Marshall
• Primary Examiner(s): Tucker, Guy V.
• Assistant Examiner(s): LEWIS, WILLIAM W
• Application Number:
  US08/457,354
• Time in Patent Office: 1,035 Days
• Field of Search: 606/108, 606/191, 606/192, 606/194, 606/195, 606/198, 606/200, 623/1, 623/12
• US Class Current: 623/1.15
• CPC Class Codes: A61F 2/856 Single tubular stent with a side portal passage
• 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 2002/91541 Adjacent bands are arranged out of phase
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2230/0054 V-shaped

Abstract

There is disclosed a stent for implanting in the body. The stent is formed of a tube having a patterned shape which has first and second meander patterns having axes extending in first and second directions. The first meander patterns can be formed into even and odd first meander patterns. The even and odd first meander patterns are 180° out of phase with each other and the odd patterns occur between every two even patterns. The second meander patterns are intertwined with the first meander patterns. The first and second directions can be orthogonal to each other. The second meander patterns can also be formed of even and odd patterns.

Claims

1. A stent formed of a tube having a patterned shape, the patterned shape comprising:

even first meander patterns having axes extending in a first direction;

odd first meander patterns, also having axes extending in said first direction, wherein said odd first meander patterns are 180°

out of phase with said even first meander patterns and occur between every two even first meander patterns;

second meander patterns having axes extending in a second direction, wherein said second meander patterns are intertwined with said even and odd first meander patterns to form a distributed structure,

wherein said second meander patterns have two loops per period and

wherein said even and odd first meander patterns are connected on first and second sides, respectively, of each loop.

2. The stent of claim 1, wherein said second meander patterns define a plurality of flexible arcuate compensating members adapted to elongate in said second direction to compensate for the tendency of said first meander patterns to foreshorten when said stent is expanded.

3. A stent formed of a tube having a patterned shape, the patterned shape comprising:

even first meander patterns having axes extending in a first direction;

odd first meander patterns, also having axes extending in said first direction, wherein said odd first meander patterns are 180°

out of phase with said even first meander patterns and occur between every two even first meander patterns;

second meander patterns having axes extending in a second direction, wherein said second meander patterns are intertwined with said even and odd first meander patterns to form a distributed structure, and

wherein said second meander patterns are formed of even and odd second meander patterns.

4. A stent according to claim 3 and wherein said even and odd first meander patterns have loops and wherein said even and odd second meander patterns are connected to said even and odd first meander patterns so as to leave one full loop between each pair of even and odd second meander patterns.

5. The stent of claim 3, wherein said second meander patterns define a plurality of flexible arcuate compensating members adapted to elongate in said second direction to compensate for the tendency of said first meander patterns to foreshorten when said stent is expanded.

6. An expandable stent defining a longitudinal aperture, including:

a plurality of flexible connected cells, each of said flexible cells comprising;

a) a first member having a longitudinal component having a first end and a second end;

b) a second member having a longitudinal component having a first end and a second end,

c) a third member having a longitudinal component having a first end and a second end;

d) a fourth member having a longitudinal component having a first end and a second end;

e) a first loop defining a first angle disposed between said first end of said first member and said first end of said second member;

f) a second loop defining a second angle disposed between said second end of said third member and said second end of said fourth member, and disposed generally opposite to said first loop;

g) a first flexible compensating member or flexible link having a first end and a second end disposed between said first member and said third member, said first end of said first flexible compensating member or flexible link communicating with said second end of said first member and said second end of said first flexible compensating member or flexible link communicating with said first end of said third member, said first and said second ends disposed a variable longitudinal distance from each other;

h) a second flexible compensating member or flexible link having a first end and a second end disposed between said second member and said fourth member, said first end of said second flexible compensating member or flexible link communicating with said second end of said second member and said second end of said second flexible compensating member or flexible link communicating with said first end of said fourth member, said first and said second ends disposed a variable longitudinal distance from each other, said first and said second flexible compensating member or flexible links differentially extendable or compressible when said stent is bent in a curved direction away from the longitudinal axis of said aperture; and

i) said first, said second, said third, and said fourth members and said first and said second loops, and said first and said second flexible compensating member or flexible links disposed so that as said stent is expanded the distance between said first and said second flexible compensating member or flexible links increases and the longitudinal component of said first, second, third and fourth members decreases while said first and said second loops remain generally opposite to one another, the ends of said first and said second flexible compensating member or flexible links open so as to increase said variable longitudinal distance between said first and said second ends of said first flexible compensating member or flexible link and so as to increase said variable longitudinal distance between said first and said second ends of said second flexible compensating member or flexible link so as to compensate for the decreasing of the longitudinal component of said first, second, third, and fourth members and substantially lessen the foreshortening of said stent upon its expansion.

7. The stent of claim 6, wherein the material of said first and said second compensating members is provided with a width that is smaller than the width of the material of said first and said second loops.

8. The stent according to claim 7 wherein said compensating members define an area of inflection between said first end and said second end and said area of inflection remains inflected after the expansion of said stent.

9. The stent of claim 8 in which the area of inflection enlarges during the expansion of the stent.

10. The stent of claim 6, in which said members are generally straight.

11. The stent of claim 6, wherein said first flexible compensating member or flexible link is arcuate and said second flexible compensating member or flexible link is arcuate and said compensating members elongate in an amount substantially equal to the amount that the distance between the ends of said first and second members and said third and fourth members increases when said stent is expanded.

12. The stent of claim 6, wherein said cells define a uniform cellular structure.

13. The stent of claim 6, wherein said first flexible compensating member or flexible link and said second flexible compensating member or flexible link also serve to connect other cells which themselves have first and second compensating members.

14. The stent of claim 6, wherein said first and said second flexible compensating member or flexible links do not tend to project into or outside of said longitudinal aperture when said stent is expanded.

15. The stent of claim 6, wherein said first and said second flexible compensating member or flexible links do not tend to project into or outside of said longitudinal aperture when said stent is flexed.

16. An expandable stent having a longitudinal axis, which consists essentially of:

a plurality of flexible cells having a longitudinal axis and a first longitudinal and a second longitudinal end, said cells disposed about the circumference of the stent, each of said cells comprising;

a first pair of members connected by an area of inflection generally disposed at said first longitudinal end of said cell;

a second pair of members connected by an area of inflection generally disposed at said second longitudinal end of said cell; and

a plurality of flexible links connecting said first and second pair of members and generally disposed between each neighboring cell about the circumference of said stent, wherein said flexible links have some area with a width smaller than the width of said areas of inflection.

17. An expandable stent, including:

a plurality of connected cells defining a substantially uniform structure defining a longitudinal aperture having a longitudinal axis, said cells arranged in a plurality of bands, each of said bands lying in a plane substantially perpendicular to said longitudinal axis, each of said plurality of cells in each of said bands comprising;

a) a first member having a first end and a second end;

b) a second member having a first end and a second end,

c) a third member having a first end and a second end;

d) a fourth member having a first end and a second end;

e) a first loop defining a first angle disposed between said first end of said first member and said first end of said second member;

f) a second loop defining a second angle disposed between said second end of said third member and said second end of said fourth member;

g) a first flexible arcuate compensating member disposed between said second end of said first member and said first end of said third member;

h) a second flexible arcuate compensating member disposed between said second end of said second member and said first end of said fourth member, said first flexible arcuate compensating member and said second flexible arcuate compensating member of each of said plurality of cells in each of said plurality of bands flexibly connecting adjacent bands.

18. The stent of claim 17 wherein said first and said second flexible arcuate compensating members are adapted to lengthen upon the expansion of said stent to compensate for the tendency of said stent to foreshorten when said stent is expanded.

19. The stent of claim 18 wherein said first and said second flexible arcuate compensating members elongate in an amount substantially equal to the amount that the distance between the ends of said first and second members and said third and fourth members increases when said stent is expanded by a catheter balloon.

20. The stent of claim 17, wherein said first and said second flexible arcuate compensating members are readily differentially compressible or expandable when said stent is unexpanded and are less differentially compressible or expandable after said stent is expanded.

21. The stent of claim 17, wherein said first and said second flexible arcuate compensating members are provided with a width that is smaller than the width of said first, said second, said third, and said fourth members and said first loop and said second loop.

22. A stent formed of a tube having a patterned shape, the patterned shape comprising:

first meander patterns which are periodic about axes extending in a first direction;

second meaner patterns which are periodic about axes extending in a second direction different than said first direction, wherein said second meander patterns are intertwined with said first meander patterns to form a generally uniform distributed structure, wherein said second meander patterns define a plurality of flexible arcuate compensating members adapted to elongate in said second direction to compensate for the tendency of said first meander patterns to foreshorten when said stent is expanded.

23. A generally longitudinally extending tubular stent which is substantially uniformly flexible with respect to its longitudinal axis by the flexibility of its cells with respect to said axis including:

(a) a plurality of cells flexible around said longitudinal axis connected to one another about the circumference of said stent to form a band of flexible cells, each of said flexible cells having apices disposed apart and generally opposite to one another along said longitudinal extension of the cell,

(b) each of said flexible cells having a plurality of flexible links disposed apart and generally opposite to one another along the circumferential extension of said cells,

(c) each of said flexible links including a plurality of portions with neighboring portions having an area of inflection therebetween; and

(d) said flexible cells in said adjacent bands of flexible cells connected to one another.

24. A flexible connector for connecting the apices of cells included in a stent, including:

a flexible member having a first end and a second end with an area of inflection disposed between said first end and said second end, a portion of said flexible member having a width smaller than the width of said apices to which said first end and said second end are connected.

25. The connector of claim 24, wherein said portion is in said area of inflection.

26. The connector of claim 24, wherein said portion is adjacent to each side of the center of the area of inflection.

27. The connector of claim 24, wherein said portion is disposed between said first end and said second end.

28. An expandable stent, including:

a plurality of connected cells having a longitudinal axis defining a substantially uniform structure of flexible cells having a longitudinal axis and a circumferential axis substantially perpendicular to said longitudinal axis;

each of said flexible cells having apices disposed apart and generally opposite to one another along said longitudinal axis of each of said cells;

each of said flexible cells having at least two flexible links disposed apart and generally opposite to one another about the circumferential extension of the cell, each of said flexible links including at least two portions with an area of inflection therebetween.

29. An expandable stent, consisting essentially of:

a plurality of flexible cells disposed about the circumference of the stent, each of said cells having a first longitudinal end and a second longitudinal end, each of said cells comprising;

a first pair of members connected by an area of inflection generally disposed at said first longitudinal end of each of said cells;

a second pair of members connected by an area of inflection generally disposed at said second longitudinal end of each of said plurality of cells; and

a flexible link connecting said first and second pair of members and generally disposed about the circumference of the stent between each neighboring cell.

31. The stent of claim 29 or 30, wherein said flexible links have some area with a width smaller than the width of said areas of inflection.

30. An expandable stent having a longitudinal axis, comprising:

a plurality of flexible cells having a longitudinal axis and a first longitudinal and a second longitudinal end, said cells disposed about the circumference of the stent, each of said cells comprising;

a first pair of members connected by an area of inflection generally disposed at said first longitudinal end of said cell;

a second pair of members connected by an area of inflection generally disposed at said second longitudinal end of said cell; and

a plurality of flexible links connecting said first and second pair of members and generally disposed between each neighboring cell about the circumference of said stent.