Balloon expandable crush-recoverable stent device

• US 20060020324A1
• Filed: 07/21/2004
• Published: 01/26/2006
• Est. Priority Date: 07/21/2004
• Status: Active Grant

• Current Assignee: REVA Medical Inc.
• Original Assignee: REVA Medical Inc.
• Inventors: Schmid, Eric V., Nguyen, John, Morris, Andrew, Simpson, Philip J., Eisele, Robert F., Padilla, Orlando M., Howard, Steven C.
• Granted Patent: US 7,763,065 B2
• Time in Patent Office: Days
• US Class Current: 623/1.160
• CPC Class Codes: A61F 2/01 Filters implantable into blood vessels
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/856 Single tubular stent with a side portal passage
• 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 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2002/075 the stent being loosely attached to the graft material, e.g. by stitching

Abstract

An intraluminal, balloon expandable stent for implantation in a body lumen is disclosed. The present invention provides a lumen support stent with an unobstructed through-lumen for use in a blood vessel. A constraining mechanism is provided for securely maintaining the stent in the collapsed condition during delivery. The stent is preferably formed with a series of interconnected slide and lock mechanisms for permitting movement from a collapsed condition to an expanded condition and inhibiting radial recoil from the expanded condition. The stent may be formed from a shape memory alloy for providing crush-recovery after deployment.

Claims

1. A balloon expandable crush-recoverable stent, comprising:

at least two substantially non-deforming elements arranged to form a tubular member, the non-deforming elements being slidably interconnected for allowing the tubular member to expand from a collapsed diameter to an expanded diameter;

wherein the non-deforming elements are fabricated from a shape-memory material for providing crush-recoverability.

2. The balloon expandable crush-recoverable stent of claim 1, wherein the non-deforming elements further comprise a locking mechanism for maintaining the tubular member in the expanded diameter after deployment at a treatment site.

3. The balloon expandable crush-recoverable stent of claim 1, wherein the non-deforming elements further comprise a constraining mechanism for maintaining the tubular member in the collapsed diameter until released by radial expansion of an inflatable balloon during deployment at a treatment site.

4. The balloon expandable crush-recoverable stent of claim 2, wherein the locking mechanism comprises a plurality of teeth disposed along at least one of the non-deforming elements, the plurality of teeth being configured for engaging an engagement member on an adjacent non-deforming element for allowing slidable movement in only one direction.

5. The balloon expandable crush-recoverable stent of claim 4, wherein the plurality of teeth is disposed along at least one deflectable member for allowing the engagement member to pass over the teeth during expansion of the tubular member.

6. The balloon expandable crush-recoverable stent of claim 4, wherein the teeth are deflectable for allowing the engagement member to pass over the teeth during expansion of the tubular member.

7. The balloon expandable crush-recoverable stent of claim 4, wherein the plurality of teeth allows the tubular member to be maintained at a selectable expanded diameter.

8. The balloon expandable crush-recoverable stent of claim 3, wherein the constraining mechanism comprises at least one hold-down tab disposed along at least one of the non-deforming elements, the hold-down tab configured to be releasably held within a capturing portion disposed on an adjacent non-deforming element.

9. The balloon expandable crush-recoverable stent of claim 3, wherein the constraining mechanism comprises at least one hook disposed along at least one of the non-deforming elements, the hook configured to be releasably held within a loop-shaped member on an adjacent non-deforming element during delivery to the treatment site.

10. The balloon expandable crush-recoverable stent of claim 1, wherein the tubular member is configured for delivering a therapeutic agent to a vessel wall at a treatment site.

11. The balloon expandable crush-recoverable stent of claim 10, wherein the therapeutic agent is an antiproliferative agent.

12. The balloon expandable crush-recoverable stent of claim 1, further comprising a retractable sheath sized for enclosing the tubular member during delivery to a treatment site.

13. A stent delivery system, comprising:

the balloon expandable crush-recoverable stent of claim 1;

and

a catheter with an inflatable balloon disposed along a distal end portion, wherein the stent is provided along an outer surface of the inflatable balloon during delivery to a treatment site.

43. A method for treating a vessel at a treatment site, comprising:

positioning the stent delivery system of claim 13 at the treatment site; and

inflating the inflatable balloon for causing the stent to expand from the collapsed diameter to the expanded diameter.

14. A balloon expandable crush-recoverable stent, comprising:

a substantially flat sheet fabricated from a shape-memory material, the flat sheet being configured to be rolled into a cylindrical configuration for providing a tubular member, the tubular member being configured for expansion from a collapsed diameter to an expanded diameter;

a locking mechanism provided along the tubular member for maintaining the tubular member in the expanded diameter after deployment at a treatment site; and

a constraining mechanism provided along the tubular member for maintaining the tubular member in the collapsed diameter until released by radial expansion of an inflatable balloon during deployment at a treatment site.

15. The balloon expandable crush-recoverable stent of claim 14, wherein the locking mechanism comprises a plurality of teeth along a first end portion and an engagement member along a second end portion and wherein the engagement member is configured for slidable engagement with the teeth.

16. The balloon expandable crush-recoverable stent of claim 14, wherein the constraining mechanism comprises a hold-down tab along a first end portion and a recess along a second end portion, wherein the recess is configured for capturing the hold-down tab.

17. The balloon expandable crush-recoverable stent of claim 14, wherein the tubular member is configured for delivering a therapeutic agent to a vessel wall at a treatment site.

18. A balloon expandable crush-recoverable stent, comprising:

a tubular member comprising a series of pivotally connected links fabricated from a shape-memory material, the pivotally connected links being configured for allowing the tubular member to be adjusted from a collapsed diameter to an expanded diameter;

a locking mechanism configured for maintaining the tubular member in the expanded diameter after deployment at a treatment site; and

a constraining mechanism configured for maintaining the tubular member in the collapsed diameter until released by radial expansion of an inflatable balloon during deployment at a treatment site.

19. The balloon expandable crush-recoverable stent of claim 18, wherein the tubular member is configured for delivering a therapeutic agent to a vessel wall at a treatment site.

20. An expandable stent, comprising:

a tubular member comprising a series of slidably interconnected elements fabricated from a biocompatible material, the tubular member being configured for expansion from a collapsed diameter to an expanded diameter;

a locking mechanism disposed along the interconnected elements for maintaining the tubular member in the expanded diameter after deployment at a treatment site; and

a constraining mechanism disposed along the interconnected elements for maintaining the tubular member in the collapsed diameter until released by radial expansion of an inflatable balloon during deployment at a treatment site.

21. The expandable stent of claim 20, wherein the biocompatible material includes a therapeutic agent for delivery to a vessel wall.

22. An expandable stent, comprising:

first and second expandable modules, each expandable module forming a substantially tubular member and being adjustable from a collapsed condition to an expanded condition;

a flexible coupling portion for coupling the first and second expandable modules together; and

a constraining mechanism provided along at least one of the first and second expandable modules for maintaining the stent in the collapsed condition during delivery to a treatment site;

wherein each of the expandable modules is substantially independently expandable.

23. The expandable stent of claim 22, wherein at least one of the expandable modules is fabricated from a shape memory material.

24. The expandable stent of claim 22, wherein at least one of the expandable module comprises a plurality of substantially non-deforming elements slidably interconnected for allowing the stent to expand from the collapsed condition to the expanded condition.

25. The expandable stent of claim 24, wherein the slidable interconnection of the elements allows movement in only one direction, thereby providing a locking mechanism for maintaining the stent in the expanded condition after deployment.

26. The expandable stent of claim 25, wherein each element further comprises a plurality of angled teeth and a locking tab, and wherein the locking tab on a first element is held within the teeth on a second element for providing the locking mechanism.

27. The expandable stent of claim 24, wherein each element further comprises a hold-down tab and at least one capturing portion, and wherein the hold-down tab on a first element is held within the capturing portion of a second element for providing the constraining mechanism.

28. The expandable stent of claim 27, wherein the hold-down tab is deformable such that the hold-down tab is releasable from the capturing portion under a sufficient radial force during deployment.

29. The expandable stent of claim 27, wherein the capturing portion is deformable such that the hold-down tab is releasable from the capturing portion under a sufficient radial force during deployment.

30. The expandable stent of claim 24, wherein each element further comprises at least one hook and at least one loop, and wherein the hook on a first element is releasably held within the loop on a second element for providing the constraining mechanism.

31. The expandable stent of claim 30, wherein the hook is configured to be sufficiently deformable such that the hook is releasable from the loop under a sufficient radial force during deployment.

32. The expandable stent of claim 26, wherein each element further comprises first and second deflectable members extending along a circumference of the stent, and wherein the angled teeth are provided along the first and second deflectable members.

33. The expandable stent of claim 32, wherein the locking tab is slidably held within a gap between the first and second deflectable members for engagement with the angled teeth.

34. The expandable stent of claim 32, wherein the locking tab is configured to cause the deflectable members to deflect apart during expansion of the expandable module, thereby allowing the locking tab to slidably pass between the deflectable members.

35. An expandable stent for supporting a blood vessel, comprising:

a tubular member fabricated from a biocompatible material, the tubular member having a first end portion and a second end portion, the tubular member being configured for expansion from a collapsed diameter to an expanded diameter, the tubular member having a central region disposed between the first end portion and the second end portion;

a locking mechanism for maintaining the tubular member in the expanded diameter after deployment at a treatment site; and

a constraining mechanism for maintaining the tubular member in the collapsed diameter until released by radial expansion of an inflatable balloon during deployment at a treatment site;

wherein at least a portion of the central region of the tubular member is formed with a substantially impermeable wall.

36. The expandable stent of claim 35, wherein the impermeable wall extends at least 2 mm along the length of the stent.

37. The expandable stent of claim 35, further comprising an opening formed through the impermeable wall for allowing blood to pass into a branch vessel.

38. A balloon expandable crush-recoverable stent, comprising:

a first row of radial elements extending along the longitudinal axis of the stent;

a second row of radial elements extending along the longitudinal axis of the stent;

wherein the radial elements in the first row slidably interconnect with the radial elements in the second row for providing a series of expandable modules, wherein each of the modules is expandable to a different diameter.

39. The balloon expandable crush-recoverable stent of claim 38, further comprising constraining mechanisms for maintaining the expandable modules in a collapsed diameter until released by radial expansion of an inflatable balloon during deployment at the treatment site.

40. The balloon expandable crush-recoverable stent of claim 38, wherein at least some of the radial elements in each of the first and second rows are coupled by flexible coupling members.

41. The balloon expandable crush-recoverable stent of claim 38, wherein the radial elements in each of the first and second rows are coupled together in a staggered arrangement.

42. A balloon expandable crush-recoverable stent, comprising:

a first flexible member extending along the longitudinal axis of the stent; and

a second flexible member extending along the longitudinal axis of the stent;

wherein the first and second flexible members form at least a portion of a tubular member, the first and second flexible members being slidably interconnected along a plurality of points for allowing the tubular member to expand from a collapsed condition to an expanded condition.

44. A balloon expandable crush-recoverable stent, comprising:

first and second expandable modules, each module comprising a series of slidably interconnected elements fabricated from a shape-memory material, the interconnected elements being configured for allowing the module to be adjusted from a collapsed diameter to an expanded diameter;

a locking mechanism disposed on each of the first and second expandable modules, the locking mechanism being configured such that the interconnected elements are slidable in only one direction for maintaining the expandable module in the expanded diameter;

a constraining mechanism disposed on each of the first and second expandable modules, the constraining mechanism being configured to maintain the expandable module in the collapsed diameter until released by radial expansion of an inflatable balloon during deployment at a treatment site; and

a flexible coupling portion for coupling the first and second expandable modules together;

wherein each of the expandable modules is substantially independently expandable.

45. A balloon expandable stent, comprising:

at least two substantially flat elements configured to be rolled into a cylindrical configuration to provide a tubular member, each of the flat elements forming a portion of a circumference of the tubular member, the elements being slidably interconnected for allowing the tubular member to expand from a collapsed diameter to an expanded diameter without any substantial plastic deformation of the elements; and

an expandable sheath disposed over the tubular member, the expandable sheath being configured to expand during deployment of the stent at a treatment site.

46. The balloon expandable stent of claim 45, wherein the elements are fabricated from a shape-memory material for providing the tubular member with crush-recoverability.

47. The balloon expandable stent of claim 46, wherein the expandable sheath is configured for use as a vessel graft at a treatment site.