Expandable stent and method for delivery of same

• US 7,094,255 B2
• Filed: 05/21/2004
• Issued: 08/22/2006
• Est. Priority Date: 03/05/1996
• Status: Expired due to Fees

• Current Assignee: Evysio Medical Devices ULC (Evysio Medical Devices)
• Original Assignee: Evysio Medical Devices ULC (Evysio Medical Devices)
• Inventors: Ricci, Donald R., Penn, Ian M.
• Primary Examiner(s): McDermott, Corrine
• Assistant Examiner(s): Matthews, William H.
• Application Number:
  US10/849,990
• Publication Number:
  US 20040236404A1
• Time in Patent Office: 823 Days
• Field of Search: 623/1.15, 623/1.17, 623/1.18, 623/1.19, 623/1.2, 623/1.34, 623/1.35, 623/1.39
• US Class Current: 623/1.15
• 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 2002/825 having longitudinal struts
• CPC Class Codes: A61F 2002/828 Means for connecting a plurality of stents allowing flexibility of the whole structure
• 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 2002/91575 connected peak to trough
• 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 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2250/0018 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0029 differing in bending or flexure capacity
• CPC Class Codes: A61F 2250/0036 differing in thickness

Abstract

An expandable stent having a proximal end and a distal end in communication with one another, and a tubular wall disposed between the proximal end and the distal end. The tubular wall has a longitudinal axis and a porous surface defined by a plurality of intersecting members comprising a series of longitudinal struts disposed substantially parallel to the longitudinal axis of the stent. Each longitudinal strut in the series comprises flexure members for substantially complementary extension and compression of a diametrically opposed pair of the longitudinal struts upon flexure of the stent. The flexure members may comprise first and second curved sections which are of a different size. At least one of the curved sections may comprise an arc of greater than about 180°.

Claims

1. An expandable stent comprising:

a proximal end and a distal end in communication with one another,

a tubular wall disposed between the proximal end and the distal end, the tubular wall having a longitudinal axis and a porous surface defined by a plurality intersecting members arranged to define a first repeating pattern comprised of a polygon having;

(i) a pair of side walls substantially parallel to the longitudinal axis,

(ii) a single concave-shaped first end wall having a first apex, and

(iii) a single convex-shaped second end wall having a second apex, the concave-shaped first end wall and the convex-shaped second end wall connecting the side walls, at least one of the first apex and the second apex being substantially flat, the stent being expandable from a first, contracted position to a second, expanded position upon the application of a radially outward force on the stent;

wherein each side wall (i) is connected to a corresponding end wall portion that is substantially orthogonal to the longitudinal axis, and (ii) comprises at least a flex member connected to at least one straight segment disposed substantially parallel to the longitudinal axis, the flex member comprising a curved shape, which curves in a non-radial direction of the stent.

2. The stent defined in claim 1, wherein the flex member, in two dimensions, comprises an S shape.

3. The stent defined in claim 1, wherein the flex member, in two dimensions, comprises a U shape.

4. The stent defined in claim 1, wherein the flex member, in two dimensions, comprises at least one lateral section having a round apex.

5. The stent defined in claim 1, wherein the flex member, in two dimensions, comprises a single lateral section, the lateral section comprising a pair of straight segments substantially orthogonal to the longitudinal axis, the straight segments being interconnected by a curved section.

6. The stent defined in claim 1, further comprising a medicinal coating disposed thereon.

7. A stent system comprising a balloon catheter having an expandable portion, the expandable portion having disposed thereon the stent defined in claim 1.

8. The stent defined in claim 1, wherein at least one of the first wall and the second wall has a flat apex and the other of the first wall and the second wall has a rounded apex.

9. The stent defined in claim 8, wherein the flat apex comprises a pair of rounded shoulders.

10. The stent defined in claim 1, wherein the concave-shaped first end walls and the convex-shaped second end walls are disposed as a plurality of undulating circumferential portions connected to the side walls.

11. An unexpanded stent comprising:

a tubular wall having a series of undulating circumferential portions, each circumferential portion comprising alternating peaks and valleys;

the tubular wall also having a plurality of longitudinal portions connecting said series of undulating circumferential portions to form a porous, cylindrical surface;

a longitudinal portion of said plurality of longitudinal portions connecting a peak in a first circumferential portion with a valley in a second circumferential portion adjacent to the first circumferential portion; and

each of said plurality of longitudinal portions having a single flexure member interposed between a pair of straight strut portions which are disposed parallel to a longitudinal axis of the stent, the flexure member, comprises a U-shape curving in a non-radial direction of the stent.

12. The stent defined in claim 11, wherein said flexure member, in two dimensions, has a width less than a width of said undulating circumferential portions when measured on an outer surface of the tubular wall.

13. The stent defined in claim 11, wherein the porous, cylindrical surface comprises a repeating pattern comprised of a polygon having a pair of side walls substantially parallel to a stent longitudinal axis, and wherein the flexure member is disposed in each of the side walls.

14. The stent defined in claim 13, wherein the polygon further comprises a first wall having a concave shape and a second wall having a convex shape.

15. The stent defined in claim 11, further comprising a medicinal coating disposed thereon.

16. A stent system comprising a balloon catheter having an expandable portion, the expandable portion having disposed thereon the stent of claim 15.

17. The stent defined in claim 11, wherein at least one of the first wall and the second wall has a flat apex and the other of the first wall and the second wall has a rounded apex.

18. The stent defined in claim 17, wherein the flat apex comprises a pair of rounded shoulders.

19. An unexpanded stent comprising:

a tubular wall having a series of undulating circumferential portions, each circumferential portion comprising alternating peaks and valleys;

the tubular wall also having a plurality of longitudinal portions connecting said series of undulating circumferential portions to form a porous, cylindrical surface;

a longitudinal portion of said plurality of longitudinal portions connecting a peak in a first circumferential portion with a valley in a second circumferential portion adjacent to the first circumferential portion; and

each of said plurality of longitudinal portions having a flexure member interposed between a pair of straight strut portions which are disposed parallel to a longitudinal axis of the stent, the flexure member, in two dimensions, comprising a U-shape,

wherein the porous, cylindrical surface comprises a repeating pattern comprised of a polygon having a pair of side walls substantially parallel to a stent longitudinal axis, wherein the polygon further comprises a first wall having a concave shape and a second wall having a convex shape,

wherein the flexure member is disposed in each of the side walls, and

wherein at least one of the first wall and the second wall has a flat apex and the other of the first wall and the second wall has a rounded apex.

20. The stent defined in claim 19, wherein the flat apex comprises a pair of rounded shoulders.

21. An unexpanded stent comprising:

a tubular wall comprising;

(i) a series of undulating circumferential portions, each circumferential portion comprising alternating peaks and valleys, and

(ii) a plurality of longitudinal portions connecting said series of undulating circumferential portions to form a porous, cylindrical surface comprising a repeating pattern comprised of a polygon having a pair of side walls substantially parallel to a stent longitudinal axis, and

wherein a flexure member is disposed in each of the side walls, the polygon further comprising a first wall having a concave shape and a second wall having a convex shape,

at least one of the first wall and the second wall having a flat apex, and the other of the first wall and the second wall having a rounded apex, the flat apex comprising a pair of rounded shoulders;

a longitudinal portion connecting a peak in a first circumferential portion with a valley in a second circumferential portion adjacent to the first circumferential portion; and

each of said plurality of longitudinal portions having a curved flexure member that provides lateral flexibility to said stent and is disposed within each of said plurality of longitudinal portions, each said flexure member, in two dimensions, comprising a pair of substantially straight strut portions disposed substantially orthogonal to a longitudinal axis of the stent, the pair of substantially straight strut portions being interconnected by a curved portion.

22. The stent defined in claim 21, wherein the longitudinal portions are aligned in a spaced relationship parallel to a stent longitudinal axis.

23. The stent defined in claim 21, further comprising a medicinal coating disposed thereon.

24. A stent system comprising a balloon catheter having an expandable portion, the expandable portion having disposed thereon the stent of claim 23.

25. The stent defined in claim 21, wherein the flexure member curved portion is curved in a non-radial direction of said stent.