Stent with controlled expansion

• US 6,613,077 B2
• Filed: 03/27/2001
• Issued: 09/02/2003
• Est. Priority Date: 03/27/2001
• Status: Expired due to Fees

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Gilligan, Sean, OʼBrien, Barry
• Primary Examiner(s): Willse, David H.
• Assistant Examiner(s): GHERBI, SUZETTE JAIME J
• Application Number:
  US09/818,338
• Publication Number:
  US 20020143381A1
• Time in Patent Office: 889 Days
• Field of Search: 623/1.15, 623/1-8-, 623/1.2, 623/1.42, 623/1.31, 623/1.3, 623/1.12, 623/1.38
• US Class Current: 623/1.12
• CPC Class Codes: A61F 2/86 Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2002/075 the stent being loosely attached to the graft material, e.g. by stitching
• CPC Class Codes: A61F 2230/0078 hyperboloidal
• CPC Class Codes: Y10S 623/903 Blood vessel

Abstract

An intraluminal prosthesis composed of a self-expandable stent and a biodegradable constraining element being capable of biodegrading in vivo over a predetermined period of time to permit radial expansion of the stent. The constraining elements are applied to the stent to produce a compressed configuration. Dissolution of the constraining elements in vivo allows for expansion of the stent to an expanded configuration.

Claims

1. An intraluminal prosthesis comprising:

a. an intraluminal stent comprising opposing end portions and a medial portion therebetween, said stent being radially self-expandable between a compressed diameter and a fully-expanded diameter; and

b. a biodegradable constraining element applied to said stent so as to prevent radial expansion of said medial portion of said stent to said fully-expanded diameter, thereby limiting radial expansion of said medial portion of said stent to a diameter intermediate of said compressed and fully expanded diameters said biodegradable constraining element biodegrading in vivo over a period of time to permit radial expansion of said portion of said stent to said fully-expanded diameter;

wherein said opposing end portions are not constrained and therefore are permitted to expand to the fully-expanded diameter, contacting a vessel wall upon implantation.

2. An intraluminal prosthesis as in claim 1, wherein said biodegradable constraining element comprises a biodegradable suture helically wrapped about said selected portion of said stent.

3. An intraluminal prosthesis as in claim 1, wherein said biodegradable constraining element comprises a plurality of biodegradable sutures circumferentially wrapped about said selected portion of said stent at axially-spaced positions.

4. An intraluminal prosthesis as in claim 1, wherein said stent comprises an undulating member helically wound along a longitudinal axis, forming a series of waves.

5. An intraluminal prosthesis as in claim 4, wherein said biodegradable constraining element is intertwined between said waves at said selected portion of said stent.

6. An intraluminal prosthesis as in claim 1, wherein said biodegradable constraining element is constructed of a material selected from the group consisting of poly(glycolic acid) (PGA), poly(lactic acid)(PLA), polydioxanones, polyoxalates, poly(α

-esters), polyanhydrides, polyacetates, polycaprolactones, poly(orthoesters), stereopolymers of L- and D-lactic acid, copolymers of bis(p-carboxyphenoxy) propane acid and sebacic acid, sebacic acid copolymers of α

-amino acids, copolymers of α

-amino acids and caproic acid, copolymers of α

-benzyl glutamate and polyethylene glycol, copolymers of succinate and poly(glycols), polyphosphazene, polyhydroxy-alkanoates and combinations and copolymers thereof.

7. An intraluminal prosthesis as in claim 1, wherein said biodegradable constraining element further comprises a therapeutic agent.

8. An intraluminal prosthesis as in claim 1, wherein said stent is constructed of a material selected from the group consisting of stainless steel, titanium, platinum, gold, nickel/titanium alloys, nitinol, bio-compatible metals, and inert thermoplastic materials.

9. An intraluminal prosthesis as in claim 1, further including a tubular graft coaxially coupled to said stent.

10. An intraluminal prosthesis as in claim 9, wherein said tubular graft is coaxially placed on an interior surface of said stent.

11. An intraluminal prosthesis as in claim 9, wherein said tubular graft is coaxially place on an exterior surface of said stent.

12. An intraluminal prosthesis as in claim 1, wherein said stent comprises a series of connected elongate strut portions having openings therebetween.

13. An intraluminal prosthesis as in claim 1, wherein said stent self-expands by a spring-like bias.

14. An intraluminal prosthesis as in claim 1, wherein said stent self-expands by shape memory properties.

15. An intraluminal prosthesis as in claim 1, wherein said stent has superelastic properties.

16. A method of implanting an intraluminal prosthesis within a vessel comprising:

a. providing, in a compressed first diameter, a radially self-expanding stent having opposed end portions and a medial portion therebetween, said medial portion of said stent being held in said compressed first diameter by a biodegradable constraining element;

b. delivering said stent within a vessel to an area of implantation;

c. permitting an unconstrained portion of said stent comprising said opposed end portions to radially expand to a second diameter; and

thereby engage a vessel wall; and

d. permitting in vivo biodegradation of said biodegradable constraining elements to permit said portion of said stent being held in said first compressed diameter to radially expand.

17. A method of making an intraluminal prosthesis comprising the steps of:

a providing a radially self-expanding tubular stent defining a lumen therein comprising first and second ends and a medial portion therebetween;

b. placing a biodegradable constraining element on said stent to constrain said medial portion of said stent from diametrically changing to a radially expanded state.

18. An intraluminal prosthesis as in claim 17, wherein said constraining element is wrapped about the length of said stent in a helical fashion.

19. An intraluminal prosthesis as in claim 17, wherein said constraining element is wrapped circumferentially about a portion of said stent.

20. An intraluminal prosthesis as in claim 17, wherein multiple constraining elements are placed along the length of said stent.

21. An intraluminal prosthesis as in claim 17, wherein said constraining element is placed on said stent while said stent is in the partially radially compressed state.

22. An intraluminal prosthesis as in claim 17, wherein said constraining element further comprises a therapeutic agent.