Bendable Stent

• US 20100211161A1
• Filed: 04/03/2008
• Published: 08/19/2010
• Est. Priority Date: 04/03/2007
• Status: Active Grant

• Current Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Dreher, Gäel
• Granted Patent: US 8,518,101 B2
• Time in Patent Office: Days
• US Class Current: 623/1.160
• CPC Class Codes: A61F 2/89 the wire-like elements comprising two or more adjacent rings flexibly connected by separate members
• 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 2002/91508 the meander having a difference in amplitude along the band
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2230/0054 V-shaped

Abstract

A stent formed by slitting a tube to create a matrix of struts, the slitted tube being radially expandable to a stenting disposition in which the struts exhibit a zig-zag pattern in successive loops around the circumference of the stent, the zig-zag pattern exhibiting a cusp between any two adjacent struts, with selected tied cusps of any one loop being connected by a bridge to a facing cusp of the adjacent loop and with intervening free cusps, characterised by lengthwise staggering of circumferentially adjacent said slits within said loops, wherein any two struts that are contiguous with a said tied cusp are of different lengths and any strut that extends from one free cusp to another free cusp has the same length as any other such strut such that, in the said stenting disposition, the free cusps of adjacent loops are circumferentially displaced from each other.

Claims

1. A stent formed by slitting a tube to create a matrix of struts which lie more or less parallel to each other and to the longitudinal axis of the tube, the slitted tube being radially expandable to a stenting disposition in which the struts exhibit a zigzag pattern in successive loops around the circumference of the stent, the angle each strut makes with the longitudinal axis increasing as the stent diameter increases,

the zig-zag pattern exhibiting a cusp between any two adjacent struts with selected tied cusps of any one loop being connected by a bridge to a facing cusp of the adjacent loop, the bridge extending in a direction parallel to the longitudinal axis of the tube and with intervening free cusps, between any two bridges of a loop, not being connected to the adjacent loop, wherein

lengthwise staggering of circumferentially adjacent said slits such that the length of the two circumferentially adjacent struts in the zig-zag pattern that flank a tied cusp are different and further such that, in the said stenting disposition, the free cusps of adjacent loops are circumferentially displaced from each other;

a plurality of radiopaque markers distributed around the circumference of the stent tube and located axially adjacent to one cusp and circumferentially in a recess flanked by two end cusps that are circumferentially adjacent said one cusp, the markers lying snug between the two end cusps; and

an end zone in which all of the end cusps and all of the radiopaque markers touch a notional circle transverse to a longitudinal axis of the stent, wherein the stress imposed on the stent by a pushing annulus is shared amongst all of the end cusps and all of the radiopaque markers.

2. The stent according to claim 1, the loops being endless.

3. The stent according to claim 1, the loops being successive turns of a spiral.

4. The stent according to claim 1, wherein the number of bridges between two adjacent loops is at least 2 and up to 6.

5. The stent according to claim 1, having either 24, 40, or 42 struts in each loop.

7. The stent according to claim 5, the stent having 24 struts in each loop and including 4 bridges connecting each pair of adjacent loops.

9. The stent according to claim 5, the stent having 42 struts in each loop and including 3 bridges connecting any two loops.

10. The stent according to claim 1, the bridges between any two adjacent loops being evenly distributed around the circumference.

11. The stent according to claim 1, wherein there are N struts between two successive bridges connecting two adjacent loops A and B, N being an integral even number, and N/2 being an integral odd number.

12. The stent according to claim 1, wherein there are N struts between successive bridges connecting two adjacent loops A and B, N being an integral even number, and N/2 being also an integral even number.

14. The stent according to claim 1, wherein the radiopaque markers in an end zone of the stent are evenly spaced around the circumference, at least when the stent is in its radially compact disposition prior to deployment.

15. The stent according to claim 14, wherein the markers are not all of the same shape, because of a conflict between the requirement for even spacing and the requirement that each marker fits within its respective recess.

6. (canceled)

8. (canceled)

13. (canceled)

16. A stent formed by slitting a tube to create a matrix of struts which lie more or less parallel to each other and to the longitudinal axis of the tube, the slitted tube being radially expandable to a stenting disposition in which the struts exhibit a zig-zag pattern in successive loops around the circumference of the stent, the angle each strut makes with the longitudinal axis increasing as the stent diameter increases,

the zig-zag pattern exhibiting a cusp between any two adjacent struts with selected tied cusps of any one loop being connected by a bridge to a facing cusp of the adjacent loop and with intervening free cusps, between any two bridges of a loop, not being connected to the adjacent loop, there being at least four such free cusps, and wherein

lengthwise staggering of circumferentially adjacent said slits within one of said loops, wherein any two struts that are contiguous with a said tied cusp are of different lengths and any strut that extends from one free cusp to another free cusp has the same length as any other such strut such that, in the said stenting disposition, the free cusps of adjacent loops are circumferentially displaced from each other.

17. The stent according to claim 16, the loops being endless.

18. The stent according to claim 16, including 40 struts in each loop.

19. The stent according to claim 16, including 42 struts per loop, and 3 bridges connecting any two loops.

20. The stent according to claim 16, including a plurality of radiopaque markers distributed around the circumference of the stent tube and located axially adjacent to one cusp and circumferentially in a recess flanked by two end cusps that are circumferentially adjacent said one cusp.