Stent

• US 5,735,872 A
• Filed: 10/02/1996
• Issued: 04/07/1998
• Est. Priority Date: 11/13/1995
• Status: Expired due to Term

• Current Assignee: Abbott Laboratories Limited (Abbott Laboratories Incorporated)
• Original Assignee: Navius Corp. (JOMED NV)
• Inventors: Carpenter, Kenneth W., Steinke, Thomas A., Wolf, Erich H., Roucher, Leo R. Jr., Jung, Eugene J. Jr.
• Primary Examiner(s): Lewis, William
• Application Number:
  US08/720,714
• Time in Patent Office: 552 Days
• Field of Search: 606/191, 606/194, 606/195, 606/198, 606/200, 623/1, 623/12, 128/898, 128/899
• US Class Current: 623/1.16
• CPC Class Codes: A61F 2/93 circumferentially expandable by using ratcheting locks
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts

Abstract

The present invention is a stent for insertion into an artery or other vessel. The stent is formed from a series of tubular shaped bands each formed with a first end which overlaps a second end. The overlap between the first and second ends is variable and allows each band to move between a contracted configuration and a fully expanded configuration which are within the elastic limits of the band. Each band includes a plurality of receivers and a first tab on a first edge of the band to secure each band at or near the fully expanded configuration and allow the stent to conform to the contours of the vessel. The bands are distributed along a substantially common axis to form a tube interconnected by a pair of elongated strips. In use, the stent is placed over a balloon catheter and compressed to adopt the contracted configuration. The stent is maintained in the contracted configuration by a retainer. The balloon catheter and stent are then advanced through a placement catheter to a target site where the balloon is partially inflated to free the stent for expansion to an equilibrium configuration. The balloon may then be more fully inflated to further expand any of the bands in the stent to suit the needs of the patient. The balloon is then deflated and removed, leaving the expanded stent to support that target site.

Claims

1. A stent for placement in a vessel, the stent comprising a plurality of interconnected, tubular shaped bands, at least one of the bands comprising:

a first end overlapping a second end and being moveable relative to the second end to reconfigure the band between at least a contracted configuration and a fully expanded configuration;

at least one receiver disposed on a first edge proximate one of the ends; and

a first tab projecting from the first edge proximate the other one of the ends, the first tab including a receiver section that extends substantially radially from the first edge, the receiver section being shaped to engage the receiver and inhibit the band from retracting towards the contracted configuration.

2. The stent of claim 1 comprising a retainer which retains at least one of the bands substantially in the contracted configuration and releases the band when pressure is applied to the band.

3. The stent of claim 1 wherein the band includes a plurality of spaced apart receivers formed in the first edge, proximate the first end and each receiver comprises a notch having a notch depth and wherein the first tab cantilevers from the first edge proximate the second end and extends upwardly and around an outer surface of the band.

4. The stent of claim 3 wherein the band includes an outwardly protruding lip extending a lip distance which is substantially equal to the notch depth from a second edge, substantially opposite the receivers and a second tab projecting from the second edge, proximate the second end, the second tab extending upwardly and around the outer surface of the band and interacting with the protruding lip to draw the first tab into engagement with the notches.

5. The stent of claim 4 wherein the band includes a relief proximate the first tab and the second tab which allows the first tab and the second tab to separate to facilitate movement of the first tab over the receivers.

6. The stent of claim 4 wherein at least a portion of at least one of the tabs is annealed.

7. The stent of claim 4 wherein the band includes a stop which inhibits the band from expanding farther than the fully expanded configuration.

8. The stent of claim 1 comprising at least one marker which allows for clear and easy indicating of the location of the stent in the vessel.

9. A stent for placement in a vessel, the stent comprising a plurality of interconnected, tubular shaped bands, at least one of the bands comprising:

a first end overlapping a second end and being moveable relative to the second end to reconfigure the band between at least a contracted configuration and a fully expanded configuration; and

a retainer which retains the band substantially in the contracted configuration and releases the band when sufficient pressure is applied to the band.

10. The stent of claim 9 wherein the retainer includes an adhesive for selectively securing the first end to an outer surface of the band.

11. The stent of claim 9 wherein the band includes at least one receiver disposed on a first edge proximate one of the ends, and a first tab projecting from the first edge proximate the other one of the ends, the first tab including a receiver section that is on a plane that is substantially perpendicular to a central axis of the band, the receiver section being shaped to engage the receiver and inhibit the band from retracting towards the contracted configuration.

12. The stent of claim 11 wherein each receiver comprises a notch having a notch depth, the band includes an outwardly protruding lip extending a distance which is substantially equal to the notch depth from a second edge, substantially opposite the receiver, and the band includes a second tab projecting from the second edge, proximate the second end, the second tab extending upwardly and around the outer surface of the band and interacting with the protruding lip to draw the first tab into engagement with the notch.

13. A stent for placement in a vessel, the stent comprising a plurality of interconnected, tubular shaped bands, each of the bands comprising:

a first end overlapping a second end and being moveable relative to the second end to reconfigure each band between a contracted configuration and a fully, expanded configuration;

a plurality of spaced apart receivers formed in a first edge proximate the first end, wherein, each receiver comprises a notch having a notch depth;

an outwardly protruding lip extending a lip distance which is substantially equal to the notch depth from a second edge substantially opposite the receivers;

a first tab which cantilevers from the first edge proximate the second end, the first tab extending upwardly and around an outer surface of the band, the first tab being suited to engage the notches and inhibit the tubular band from retracting towards the contracted configuration; and

a second tab which cantilevers from the second edge proximate the second end, the second tab extending upwardly and around the outer surface of the band for interacting with the protruding lip to draw the first tab into engagement with the notches.

14. The stent of claim 13 comprising a relief proximate the first end between the first tab and the second tab which allows the first tab and the second tab to separate to facilitate movement of the first tab over the receivers.

15. A stent for placement in a vessel, the stent comprising a plurality interconnected, tubular shaped bands, at least one of the bands comprising a first end overlapping a second end and being moveable relative to the second end to reconfigure the band between a contracted configuration and a fully expanded configuration, the band being made from a resilient material that is formed so that movement between the contracted configuration and the expanded configuration is within the elastic limits of the band and is formed so that an equilibrium configuration of the band is between the contracted configuration and the fully expanded configuration.

16. The stent of claim 15 wherein the band includes at least one receiver disposed on a first edge proximate one of the ends, and a first tab which cantilevers from the first edge proximate the other one of the ends, the first tab including a receiver section that extends substantially radially outwardly from the first edge, the receiver section being shaped to engage the receiver and inhibit the band from retracting towards the contracted configuration.

17. The stent of claim 16 wherein each receiver comprises a notch having a notch depth, the band includes an outwardly protruding lip extending a distance which is substantially equal to the notch depth from a second edge, substantially opposite the receiver, and the band includes a second tab projecting from the second edge, proximate the second end, the second tab extending upwardly and around the outer surface of the band and interacting with the protruding lip to draw the first tab into engagement with the notch.

18. A stent prepared by a process comprising the steps of:

forming a plurality interconnected, tubular shaped bands in a substantially flat sheet of resilient material, each band having a first end and an opposed second end; and

rolling the sheet so that the first end of each band overlaps its second end, is moveable relative to its second end within elastic limits of the band to reconfigure the band between a contracted configuration and a fully expanded configuration and has an equilibrium configuration that is between the contracted configuration and the fully expanded configuration.

19. The process of claim 18 wherein each band is formed to include a first tab extending from a first edge of the band proximate the second end and a second tab extending from a second edge of the band proximate the second end and the process includes the step of bending the first and second tabs over the an outer surface of the band after the flat sheet has been rolled.

20. A method for placing a stent at a target site in a vessel, the method comprising the steps of:

securing a stent in a substantially contracted position, with a retainer, to a balloon, the stent comprising a plurality of interconnected, tubular shaped, bands, at least one of the bands comprising a first end overlapping a second end and being moveable relative to the second end to reconfigure the band between the contracted configuration and a fully expanded configuration;

advancing the balloon and stent in the vessel until the balloon and stent are positioned substantially adjacent the target site;

releasing the retainer by partly inflating the balloon; and

allowing the bands to expand from the contracted configuration.

21. The method of claim 20 comprising the step of securing at least one of the bands proximate the fully expanded configuration with a first tab which cantilevers from a first edge of the band, the first tab having a receiver section that extends substantially radially from the first edge and that interacts with at least one receiver, the receiver being disposed proximate one of the ends and the first tab being disposed proximate the other one of the ends.

22. A method for placing a stent at a target site in a vessel, the method comprising the steps of:

securing a stent to a balloon, the stent comprising a plurality of interconnected, tubular shaped, bands, at least one of the bands comprising a first end overlapping a second end and being moveable relative to the second end to reconfigure the band between a contracted configuration and a fully expanded configuration;

advancing the balloon and stent in the vessel until the balloon and stent are positioned substantially adjacent the target site;

expanding the bands with the balloon; and

securing at least one of the bands proximate the fully expanded configuration with a first tab which cantilevers from a first edge of the band, the first tab having a receiver section that extends substantially radially from the first edge of the band and that interacts with at least one receiver, the receiver being disposed proximate one of the ends of the band and the first tab being disposed proximate the other one of the ends of the band.

23. The method of claim 22 wherein the step of securing the stent includes using a retainer that is released upon inflation of the balloon to secure the stent.