Flexible, radially expansible luminal prostheses

• US 6,270,524 B1
• Filed: 08/14/1998
• Issued: 08/07/2001
• Est. Priority Date: 11/12/1996
• Status: Expired due to Term

• Current Assignee: Medtronic Ave Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Kim, Steven W.
• Primary Examiner(s): Willse, David H.
• Assistant Examiner(s): STEWART, ALVIN J
• Application Number:
  US09/134,494
• Time in Patent Office: 1,089 Days
• Field of Search: 623/1.1, 623/1.13, 623/1.15, 623/1.16, 623/1.35, 623/1.12, 623/1.17
• US Class Current: 623/1.15
• 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 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/91566 connected trough to trough
• CPC Class Codes: A61F 2002/91591 Locking connectors, e.g. using male-female connections
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61F 2220/0058 soldered or brazed or welded
• CPC Class Codes: A61F 2220/0075 sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2250/0048 differing in mechanical expandability, e.g. in mechanical, self- or balloon expandability

Abstract

The present invention provides methods and apparatus for deploying luminal prostheses, such as stents, grafts, or stent-grafts, to luminal walls at a target site within an anatomical lumen. In one aspect of the invention, luminal prostheses are designed to negotiate curves, bends and other irregularities in body passageways so as to facilitate deployment of the stents and to minimize injury to the luminal walls. In addition, the luminal prostheses of the present invention have sufficient flexibility to bend and articulate so as to substantially conform to a tortuous body lumen at the target site, which enhances the post-deployment performance of the stent. In another aspect of the invention, methods and apparatus are provided for securing luminal prostheses to the luminal walls at a target site within an anatomical lumen. These methods and apparatus provide an effective frictional lock between the stent and the luminal wall to inhibit migration and/or failure of the stent.

Claims

1. A method for deploying a luminal prosthesis at a target site within

an anatomical lumen comprising:

providing at least two flexible tubular stent frames in a compressed configuration, the stent frames being connected with one or more bent, substantially rigid connecting structures;

introducing the tubular stent frames into an anatomical lumen; and

deploying the stent frames to conform to a curved portion in the anatomical lumen, wherein the substantially rigid connecting structures are substantially unbent during deployment.

2. The method of claim 1 further comprising implanting the tubular stent frames at a target site within a tortuous anatomical lumen, the stent frames deforming to conform to a geometry of said tortuous anatomical lumen.

3. The method of claim 2 where the stent frames each comprise a radially expansible, malleable material and the rigd connecting structures each comprise a superelastic material, the implanting step comprises:

expanding a radially expansible member within a hollow lumen of the stent frames to radially expand the stent frames at the target site; and

allowing the superelastic rigid connecting structures to return to an expanded configuration at the target site.

4. The method of claim 2, wherein the implanting step comprises:

compressing the stent frames and the rigid connecting structures into a radially compressed configuration; and

allowing the stent frames and rigid connecting structures to recover to an expanded configuration at the target site.

5. The method of claim 4 wherein the allowing step is carried out by the application of heat from the patient'"'"'s body.

6. The method of claim 1 wherein a distance between adjoining stent frames at the rigid connecting structure remains substantially constant as the stent frames articulate to conform to the curved portion of the anatomical lumen.

7. The method of claim 1 wherein the prosthesis comprises groups of three rigid connecting structures extending between adjoining stent frames and uniformly spaced around the circumference of the stent frames.

8. The method of claim 1 further comprising deforming the stent frames from a substantially circular cross-section to an elliptical cross-section as the stent frames articulate to conform to the curved portion of the anatomical lumen.

9. The method of claim 1 further comprising lining interstitial spaces between the stent frames with one or more graft liners to inhibit cell proliferation therebetween.

10. The method of claim 1 further comprising:

positioning the stent frames at the target site within the anatomical lumen;

radially expanding the tubular stent frames; and

engaging the luminal wall with one or more anchor members of the stent frames to secure the prosthesis to the luminal wall.

11. The method of claim 10 wherein the radially expanding step includes forcing portions of the luminal wall into interstitial spaces between adjoining stent frames and axially penetrating said luminal wall portions with the anchor members to form a substantially continuous mechanical wall with said luminal wall portions and said stent frames.

12. The method of claim 10 wherein each stent frame comprises a plurality of V-shaped elements defining intersection points between adjoining V-shaped elements, and the anchor members comprise one or more protrusions extending axially outward from the intersection points of a group of the V-shaped elements.

13. The method of claim 10 wherein each stent frame comprises a plurality of diamond-shaped elements defining laterally facing points and axially facing points, the diamond-shaped elements connecting to each other at the laterally facing points and the anchor members comprising protrusions extending axially outward from the axially facing points of a group of the diamond-shaped elements.

14. A method for deploying a luminal prosthesis at a target site within

a tortuous anatomical lumen comprising:

positioning a compressed luminal prosthesis having at least two flexible tubular stent frames connected together at points by one or more substantially rigid connecting structures at the target site within the anatomical lumen wherein said substantially rigid connecting structures are configured to bend when compressed; and

deforming the stent frames a sufficient amount such that the stent frames substantially conform to an inner wall surface of the anatomical lumen, and wherein said substantially rigid connecting structures maintain the stent frames at a constant distance at the connection points.

15. A method for deploying a radially expansible luminal prosthesis comprising:

providing at least two tubular stent frames sized for delivery through an anatomical lumen, each stent frame having a longitudinal axis, an open proximal end, and an open distal end;

introducing the tubular stent frames in an anatomical lumen; and

deforming a plurality of substantially rigid connecting structures configured in groups extending between and movably connecting adjoining stent frames to allow flexing of the prosthesis along the longitudinal axis wherein the substantially rigid connecting structures are more rigid than the tubular stent frames.

16. The method of claim 15, wherein the connecting structures within each group are uniformly spaced around a circumference of the stent frames and staggered relative to each other along the longitudinal axis of the prosthesis such that each connecting structure is centered between two of the connecting structures in an adjacent group.

17. The method of claim 15, wherein the stent frames have sufficient flexibility to deform into a configuration substantially conforming to a curved portion of an anatomical lumen.

18. The method of claim 15, wherein the connecting structures are substantially more rigid than the stent frames.

19. The method of claim 15, wherein said deforming of the plurality of substantially rigid connecting structures is such that each stent frame defines a transverse cross-sectional shape and wherein the cross-sectional shapes of each stent frame changes as the stent frames conform to a longitudinally curved portion of an anatomical lumen.

20. The method of claim 19, wherein the connecting structures define a distance between adjoining stent frames that remains substantially constant as the cross-sectional shapes of each stent frame changes to conform to a longitudinally curved portion of an anatomical lumen.

21. The method of claim 19, wherein the transverse cross-sectional shape is substantially elliptical.

22. The method of claim 15, wherein the connecting structures each comprise a single rigid wire.

23. The method of claim 15, wherein the groups of connecting structures each comprise two connecting structures extending between adjoining stent frames.

24. The method of claim 15, wherein the groups of connecting structures each comprise three connecting structures extending between adjoining stent frames.

25. The method of claim 15, wherein the groups of connecting structures each comprise four connecting structures extending between adjoining stent frames.

26. The method of claim 15, wherein each stent frame includes a plurality of body segments connected together to form the stent frame and at least one of a plurality of anchor members with tapering ends extending axially from the body segments and substantially parallel to the longitudinal axis of the stent frame for securing the prosthesis to the luminal wall.

27. The method of claim 26, wherein the body segments comprise V-shaped elements defining intersection points between adjoining V-shaped elements, and wherein the at least one of a plurality of anchor members comprise at least one protrusion extending axially outward from the intersection points of a group of the V-shaped elements.

28. A method comprising:

providing a plurality of tubular stent frames sized for delivery through an anatomical lumen, each stent frame having open proximal and distal ends along a longitudinal axis of the prosthesis; and

connecting each of said tubular stent frames with a plurality of bendable connecting structures configured in groups extending between adjoining stent frames, the connecting structures being more rigid than the stent frames so that the stent frames deform axially when the prosthesis conforms to a longitudinally curved portion of an anatomical lumen.

29. The method of claim 28, wherein each group defines a plurality of even circumferential interstitial spaces between the connecting structures of the group, and wherein each connecting structure is centered along an interstitial space of an adjacent group.

30. The prosthesis of claim 28, wherein alternating groups are aligned axially.