Coiled-sheet stent with flexible mesh design

• US 7,491,227 B2
• Filed: 06/16/2003
• Issued: 02/17/2009
• Est. Priority Date: 06/16/2003
• Status: Expired due to Fees

• Current Assignee: Endotex Interventional Systems Incorporated (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Inventors: Yang, Yi
• Primary Examiner(s): GHERBI, SUZETTE JAIME J
• Application Number:
  US10/462,876
• Publication Number:
  US 20040254630A1
• Time in Patent Office: 2,073 Days
• Field of Search: 623 115- 122, 623/1.34
• 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 2/92 Stents in the form of a rolled-up sheet expanding after insertion into the vessel , e.g. with a spiral shape in cross-section
• 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 2002/91541 Adjacent bands are arranged out of phase
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2220/0008 Fixation appliances for connecting prostheses to the body
• CPC Class Codes: A61F 2220/0016 with sharp anchoring protrusions, e.g. barbs, pins, spikes
• CPC Class Codes: A61F 2230/0054 V-shaped

Abstract

A coiled-sheet stent includes a tubular body having a longitudinal axis and a circumference, and a plurality of cylindrical bands formed in the tubular body, each band having a zig-zag pattern including a series of sequential diagonal elements connected to one another and extending about the circumference. A plurality of longitudinal connectors extend between and connect adjacent bands. The diagonal elements have an arcuate shape, all diagonal elements in each band being oriented in either a clockwise or counter-clockwise direction about the circumference. The tubular body is expandable between contracted and enlarged conditions, and the zig-zag pattern is expandable between unstretched and unstretched conditions, the zig-zag pattern being biased towards the stretched condition above a transition temperature, thereby at least partially defining the enlarged condition. A multi-cellular stent structure is also provided that includes a plurality of bat shaped cells formed in a tubular body, each cell defining a head region, a tail region and opposing curved wing regions, and a plurality of connectors extending between and connecting adjacent cells. The head and tail regions of adjacent cells are directly connected to one another, and connectors extend between adjacent wing regions of adjacent cells.

Claims

1. A stent comprising:

a coiled sheet having a longitudinal axis and first and second longitudinal edges, said coiled sheet having an unexpanded condition and an expanded condition, wherein said first and second longitudinal edges have a circumferential overlap of about 20% to about 100% when the coiled sheet is in the unexpanded condition;

a plurality of cylindrical bands formed in said coiled sheet, each cylindrical band comprising a generally zig-zag pattern comprising a series of sequential diagonal elements connected to one another,

a first terminal band, and a second terminal band, the first terminal band being distal of the plurality of cylindrical bands and the second terminal band being proximal of the plurality of cylindrical bands, the first and second terminal bands comprising a plurality of straight sections, pairs of straight sections being engaged to form terminal ends, at least one of the terminal ends being a slot terminal end, the slot terminal end defining a through hole, the through hole having a length;

at least one stent sleeve marker, the at least one stent sleeve marker having a length less than the length of the through hole, the marker having a first end and a second end, the first and second ends being open, the marker having a first portion, one of the slot terminal ends being disposed within each marker so that the marker is centered over the slot, the first portion of the marker being depressed into the through hole thereby engaging the maker to the slot terminal end and

a plurality of longitudinal connectors extending between and connecting adjacent cylindrical bands.

2. The stent of claim 1, wherein the coiled sheet is expandable between the unexpanded condition for facilitating introduction into a body lumen and the expanded condition for engaging a wall of a body lumen.

3. The stent of claim 2, wherein the coiled sheet is biased towards the expanded condition.

4. The stent of claim 2, wherein the zig-zag pattern is expandable between an unstretched condition and a stretched condition, the zig-zag pattern being biased towards the stretched condition above a transition temperature which is substantially below body temperature, thereby at least partially defining the expanded condition.

5. The stent of claim 4, wherein ends of adjacent diagonal elements are arranged further away from one another about the circumference in the stretched condition than in the unstretched condition.

6. The stent of claim 5, wherein the diagonal elements have a less arcuate shape in the stretched condition than in the unstretched condition such that the diagonal elements at least partially straighten for minimizing foreshortening of the coiled sheet along the longitudinal axis.

7. The stent of claim 1, wherein all of the diagonal elements in all of the bands comprising the coiled sheet are oriented in a clockwise direction about the circumference.

8. The stent of claim 1, wherein the longitudinal connectors have a longitudinal dimension which is substantially smaller than a longitudinal dimension of the diagonal elements.

9. The stent of claim 1, wherein each diagonal element comprises first and second generally straight portions having first and second ends, the second ends being connected together by a curved portion, the first ends being connected to preceding and succeeding diagonal elements.

10. The stent of claim 1, wherein the diagonal elements of each cylindrical band are out of phase with any adjacent cylindrical band.

11. The stent of claim 1, at least one of the terminal strut ends being elongated compared to other of the terminal strut ends.

12. The stent of claim 11, the elongated terminal strut ends having a stent sleeve marker engaged thereto.

13. The stent of claim 1, the terminal strut end, to which a stent sleeve marker is engaged, having a slot.

14. A stent, the stent comprising a plurality of arcuate members and a plurality of longitudinal connectors, the plurality of arcuate members and the plurality of longitudinal connectors defining a plurality of cells, each of the plurality of cells having a first wing region, a second wing region, a head region and a tail region, the first wing region extending longitudinally away from the proximal ends of head and tail regions, the second wing region extending longitudinally away from the distal ends of the head and tail regions, each wing region being defined by two arcuate members engaged to one another, each head and tail region being defined by a longitudinal connector, each arcuate member comprising a first member, a second member and an elbow, the elbow engaging the first and second members, the first member having a first curvature, the second member having a second curvature, the first curvature being opposite to the second curvature, the first member having a first length and the second member having a second length, the first length greater than the second length, the first member having a first width, the second member having a second width and the first elbow having a third width, the first width being greater than the second and third widths.

15. The stent of claim 14, the first width being about 25% to about 50% greater than the second and third widths.

16. The stent of claim 14, the first elbows each having about an 90 degree orientation when the stent is in an unexpanded state and the first elbows each having about an 130 degree orientation when the stent is in an expanded state.

17. A stent, the stent comprising a plurality of arcuate members and a plurality of longitudinal connectors, the plurality of arcuate members and the plurality of longitudinal connectors defining a plurality of cells, each of the plurality of cells having a first wing region, a second wing region, a head region and a tail region, the first wing region extending longitudinally away from the proximal ends of head and tail regions, the second wing region extending longitudinally away from the distal ends of the head and tail regions, each wing region being defined by two arcuate members engaged to one another, each head and tail region being defined by a longitudinal connector, each arcuate member comprising a first member, a second member and an elbow, the elbow engaging the first and second members, the first member having a first curvature, the second member having a second curvature, the first curvature being opposite to the second curvature, each arcuate member having a longitudinal dimension, each longitudinal connector having a longitudinal dimension, the longitudinal dimension of the longitudinal connectors being less than the longitudinal dimension of the arcuate members.

18. The stent of claim 17, the plurality of cells forming a plurality of cylindrical bands, the cells of adjacent cylindrical bands being circumferentially offset from one another.

19. A stent, the stent comprising a plurality of arcuate members and a plurality of longitudinal connectors, the plurality of arcuate members and the plurality of longitudinal connectors defining a plurality of cells, each of the plurality of cells having a first wing region, a second wing region, a head region and a tail region, the first wing region extending longitudinally away from the proximal ends of head and tail regions, the second wing region extending longitudinally away from the distal ends of the head and tail regions, each wing region being defined by two arcuate members engaged to one another, each head and tail region being defined by a longitudinal connector, each arcuate member comprising a first member, a second member and an elbow, the elbow engaging the first and second members, the first member having a first curvature, the second member having a second curvature, the first curvature being opposite to the second curvature, the stent further comprising at least one stent marker, the at least one stent marker being a hollow tube, a portion of the plurality of arcuate members forming an end of the stent, the portion of the plurality of arcuate members comprising a first arcuate member and a second arcuate member, the first and second arcuate member defining a wing region of one of the plurality of cells, the at least one stent marker being engaged to the first and second arcuate members so that the stent marker surrounds a portion of an exterior surface of the first and second arcuate members and extends between the first and second arcuate members.

20. A stent, the stent comprising a plurality of arcuate members and a plurality of longitudinal connectors, the plurality of arcuate members and the plurality of longitudinal connectors defining a plurality of cells, each of the plurality of cells having an unexpanded configuration and an expanded configuration;

each of the plurality of cells in the unexpanded configuration being bat shaped, the bat shaped cell comprising a first wing region, a second wing region, a head region and a tail region, the first wing region extending longitudinally away from the proximal ends of the head and tail regions and the second wing region extending longitudinally away from the distal ends of the head and tail regions, each wing region being defined by a first arcuate member engaged to a second arcuate member by a cotter pin connector, the head region being defined by a first longitudinal connector and the tail region being defined by a second longitudinal connector;

each of the plurality of cells in the expanded configuration being substantially square shaped.