Shape memory polymeric stent

• US 9,125,760 B2
• Filed: 02/08/2013
• Issued: 09/08/2015
• Est. Priority Date: 06/12/2007
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Jordan, Gary
• Primary Examiner(s): Anderson, Gregory
• Assistant Examiner(s): DANG, PHONG SON H
• Application Number:
  US13/763,149
• Publication Number:
  US 20130150951A1
• Time in Patent Office: 942 Days
• US Class Current: 1/1
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2210/0014 using shape memory or superelastic materials, e.g. nitinol

Abstract

An implantable, radially distensible stent includes a plurality of helically wound elongate members. The members include an overlapping portion having a longitudinal extent, opposed and convexly rounded sides defining a width of the members and opposed luminal and exterior surfaces. The members include shape memory polymer. The side of one elongate member slidingly overlaps the side of an adjacent elongate member to form a self-supporting wall structure of a stent. The stent wall is self-supporting without other support structure incorporated into or abutting the elongate members. Further, the shape memory polymer may include a biodegradable or bioabsorbable elements.

Claims

1. A stent radially distensible between a radially contracted state and a radially expanded state, wherein when the stent is in the radially contracted state and when the stent is in the radially expanded state the stent comprises:

a tubular wall having opposed open ends, an uneven outer surface, and an uneven inner surface, the inner and outer surfaces being formed by a plurality of helically wound elongate members in direct contact with one another so that the wall has substantially no gaps, adjacent elongate members being either overlapping or juxtaposed;

wherein the elongate members have a first shape in the radially contracted state, the first shape being triangular-shaped members, the triangular-shaped members comprising first triangular-shaped members having a first same triangular shape and second triangular-shaped members having a second same triangular shape different from the first same triangular shape, wherein a first triangular-shaped member overlaps a second triangular-shaped member.

2. The stent of claim 1, each elongate member having a same type of member, the shape of the elongate member in the radially contracted state being T-shaped, L-shaped, C-shaped, or I-shaped;

each elongate member having an exterior surface and a luminal surface, wherein both the exterior and luminal surfaces of two adjacent overlapping elongate members are positioned at different radial distances from the longitudinal axis of the prosthesis.

3. The stent of claim 1, the stent having a first longitudinal extent when the stent is in the radially contracted state and a second longitudinal extent when the stent is in the radially expanded state, the second longitudinal extent being greater than the first longitudinal extent.

4. The stent of claim 1, each elongate member having a same first shape;

each elongate member further having a same second shape when the stent is in the radially expanded state, the second same shape being different than the first same shape.

5. The stent of claim 1, wherein the elongate members are either helically wound in a circular fashion or in an oblique fashion.

6. The stent of claim 1, each elongate member having a shape memory portion formed of the shape memory polymer and a non-shape memory portion.

7. A prosthesis having a longitudinal axis and comprising a wall free of gaps, the wall formed entirely by a plurality of overlapping elongate members of a same shape wherein the same shape being I-shaped, each elongate member having two sides extending between the exterior and luminal surfaces, a portion of an elongate member being slidably disposed inside a cavity defined by one of the two sides of an adjacent elongate member, each elongate member having an exterior surface and a luminal surface, wherein both the exterior and luminal surfaces of two adjacent overlapping elongate members are positioned at different radial distances from the longitudinal axis of the prosthesis when the prosthesis is in a radially contracted state and when the prosthesis is in a radially expanded state.

8. The prosthesis of claim 7, wherein at least one of the exterior surface and the luminal surface is planar.

9. The prosthesis of claim 7, the shape being ribbon shaped with protuberances extending from either the exterior surface or the luminal surface.

10. The prosthesis of claim 7, wherein the wall has an uneven outer surface and an uneven luminal surface.

11. The prosthesis of claim 7, wherein the plurality of elongate members comprise a shape memory polymer, each elongate member having a first longitudinal extent when the stent is in the radially contracted state and a second longitudinal extent when the stent is in the radially expanded state, the second longitudinal extent being greater than the first longitudinal extent.

12. A prosthesis comprising a wall free of gaps, the wall formed entirely by a plurality of elongate members of a same cross-sectional shape, each elongate member having a luminal surface, an exterior surface, and two sides extending between the luminal and exterior surfaces, wherein at least one of the two sides defines a cavity wherein the plurality of elongate members being either I-beam-shaped or fork-shaped;

wherein for each two adjacent elongate members, a portion of one elongate member is slidably positioned inside the cavity of the other elongate member.

13. The prosthesis of claim 12, wherein adjacent elongate members are interlocking

14. The prosthesis of claim 12, the stent wall having an uneven outer surface and an uneven inner surface.

15. The prosthesis of claim 12, wherein at least some of the plurality of elongate members comprise a shape memory polymer.