Covered stent with encapsulated ends

• US 6,579,314 B1
• Filed: 10/29/1999
• Issued: 06/17/2003
• Est. Priority Date: 03/10/1995
• Status: Expired due to Term

• Current Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Edwin, Tarun, Layne, Richard, Koch, Guido, Supper, Wolfgang, Lombardi, Sylvie, Gamer, Walter, Kirchhoff, Thomas
• Primary Examiner(s): Dawson, Glenn K.
• Application Number:
  US09/430,154
• Time in Patent Office: 1,327 Days
• Field of Search: 623/1.13, 623/1.36, 623/1-5-, 623/1-8-, 606/198, 606/108, 606/151, 606/191-197, 606/199, 606/200, 606/213
• US Class Current: 623/1.44
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/848 having means for fixation to the vessel wall, e.g. barbs
• 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 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/072 Encapsulated stents, e.g. wire or whole stent embedded in lining
• CPC Class Codes: A61F 2002/075 the stent being loosely attached to the graft material, e.g. by stitching
• CPC Class Codes: A61F 2230/005 Rosette-shaped, e.g. star-shaped
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61L 31/048 obtained by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene

Abstract

A portion of a covered stent is encapsulated with ePTFE, so that the unencapsulated portion, which is covered by a single ePTFE covering, imparts an unimpaired flexibility to the stent. One surface of the stent, either the luminal or abluminal surface, is covered by a single continuous layer of ePTFE, while limited regions, preferably near the ends of the stent, of the other surface are also covered by ePTFE. The regions covered by ePTFE on both surfaces become encapsulated when the ePTFE of one layer becomes bonded to second layer. By leaving a middle region of the stent unencapsulated, the stent retains flexibility similar to a bare stent, thereby reducing the loading and deployment forces.

Claims

1. An implantable prosthetic device, comprising:

a stent having a luminal and an abluminal surface and a first and a second end;

a first tubular layer of expanded polytetrafluoroethylene covering the abluminal surface of the stent, wherein said first tubular layer does not cover a region immediately adjacent the first or the second end of the stent;

a second tubular layer of expanded polytetrafluoroethylene in contact with the luminal surface of the stent, wherein said second tubular layer does not cover a majority of the luminal surface of the stent, said second tubular layer comprising at least one ring disposed near the first or the second end of the stent; and

an encapsulated region wherein said first tubular layer bonds to said second tubular layer.

2. The implantable prosthetic device of claim 1, wherein said stent comprises shape memory alloy.

3. The implantable prosthetic device of claim 2, wherein said stent comprises zigzag struts forming stenting zones, wherein a plurality of scrap portions that join adjacent stenting zones are removed to form spacings between the adjacent stenting zones.

4. The implantable prosthetic device of claim 1, wherein said second tubular layer further comprises a second ring disposed at an opposite end of the stent from said at least one ring, where a second encapsulated region is formed.

5. A process for producing a flexible covered stent comprising the steps of:

providing a stent having a stent length and luminal and abluminal surfaces;

placing a first tubular covering of expanded polytetrafluoroethylene, having a first covering length, in contact with the abluminal surface of the stent so that a majority of the surface is covered thereby, but wherein a region immediately adjacent the first or the second end of the stent is left uncovered;

placing a second tubular covering of expanded polytetrafluoroethylene, having a length substantially less than the first covering length, in contact with the luminal surface of the stent; and

forming an encapsulated region by bonding the first tubular covering to the second tubular covering and leaving a majority of the stent length unencapsulated.

6. The process of claim 5, further comprising a step of placing a third tubular covering of expanded polytetrafluoroethylene, having a length substantially less than the first covering length, in contact with the luminal surface of the stent, wherein the second tubular covering and the third tubular covering are disposed in proximity to a first end and a second end of the stent, respectively, and wherein the step of forming an encapsulated region further comprises bonding the first tubular covering to the third tubular covering.

7. The process of claim 6, wherein the length of the first tubular covering is selected and one of the second and the third tubular covering is disposed so that one of the first end and the second end of the stent is left uncovered.