Self-expanding stent

• US 5,643,314 A
• Filed: 11/13/1995
• Issued: 07/01/1997
• Est. Priority Date: 11/13/1995
• Status: Expired due to Term

• Current Assignee: Abbott Laboratories Vascular Enterprises Limited (Abbott Laboratories)
• Original Assignee: Navius Corp. (JOMED NV)
• Inventors: Carpenter, Kenneth W., Roucher, Leo R. Jr., Jung, Eugene J. Jr.
• Primary Examiner(s): Buiz, Michael Powell
• Assistant Examiner(s): Lewis, William W.
• Application Number:
  US08/557,725
• Time in Patent Office: 596 Days
• Field of Search: 623/1, 623/12, 606/108, 606/191, 606/194, 606/195, 606/198, 606/200, 128/898, 128/899
• US Class Current: 623/1.2
• 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 2/92 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

Abstract

The present invention provides a self-expanding stent for insertion into an artery or other internal vessel. The stent is formed from a series of radial bands each formed with overlapping first and second ends. The overlap between the first and second ends is variable, allowing each band to move between a contracted configuration and an expanded configuration. The first and second ends of each band are both formed to include a tab which is folded to hold the first and second end against the band. The bands are distributed along a common axis to form a cylinder and 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 balloon catheter and stent are then advanced through a placement catheter and to a target site where the balloon is partially inflated to free the stent for self-expansion. The balloon may then be more fully inflated to further expand any of the radial bands in the stent. The balloon is then deflated and removed, leaving the expanded stent to support that target site.

Claims

1. A self-expanding stent for placement in a vessel which comprises:

a plurality of radial bands, each said band having a first end and a second end with said first end overlapping said second end, said first end being moveable relative to said second end to iso-concentrically reconfigure each band between a contracted configuration having a first diameter and an expanded configuration having a second diameter, each said band being biased to expand from said first diameter to nearly said second diameter with said bands disposed about a common axis;

means for interconnecting each said band to an adjacent said band;

means for locking each said radial band in said expanded configuration; and

means for locking each said radial band in said contracted configuration.

2. A self-expanding stent as recited in claim 1 wherein said means for interconnecting each said band to an adjacent said band includes a first elongated strip, said first elongated strip interconnecting said first end of each said radial band to said first end of an adjacent said band.

3. A self-expanding stent as recited in claim 1 wherein said means for interconnecting each said band to an adjacent said band includes a second elongated strip, said second elongated strip interconnecting said second end of each said radial band to said second end of an adjacent said band.

4. A self-expanding stent as recited in claim 1 wherein said means for locking each said radial band in said expanded configuration includes a projection attached to said first end of a particular radial band and a detent formed in said particular radial band, said projection and said detent positioned to engage when said radial bands are configured in said expanded configuration.

5. A self-expanding stent as recited in claim 1 wherein said means for locking each said radial band in said contracted configuration includes a projection attached to said second end of a particular radial band and a detent formed in said particular radial band, said projection and said detent positioned to engage when said radial bands are configured in said contracted configuration.

6. A self-expanding stent as recited in claim 1 wherein said stent is fabricated as a single piece of stainless steel.

7. A method for placing a self-expanding stent at a target site in a vessel of a patient which comprises the steps of:

providing a self-expanding stent which comprises a plurality of radial bands, at least one of said bands being a locking radial band, each said band having a first radial edge and a second radial edge, each said band also having a first end and a second end, said first end overlapping said second end to create an overlap region, said first end being moveable relative to said second end to substantially iso-concentrically reconfigure each band between a contracted configuration and an expanded configuration, at least one tab projecting from said first radial edge of each said locking radial band for folding said tab over said locking radial band to hold said first end and said second end of said locking radial band against said locking radial band in said overlap region, means for interconnecting said first end of each said radial band, means interconnecting said second end of each said radial band, and means for selectively locking said locking radial band in said contracted configuration and said expanded configuration;

configuring said stent to said contracted configuration over at least a portion of a balloon catheter;

advancing said expandable stent and said inflatable balloon to said target site in said vessel; and

partially inflating said balloon to unlock said radial bands and allow said radial bands to resiliently self-expand.

8. A method as recited in claim 7 which further comprises the step of further inflating said balloon to further expand said radial bands.

9. A method as recited in claim 8 which further comprises the steps of:

deflating said balloon;

repositioning said balloon;

reinflating said balloon to further expand a particular band within said plurality of bands.