Covered stent and method of covering a stent

• US 6,808,533 B1
• Filed: 07/28/2000
• Issued: 10/26/2004
• Est. Priority Date: 07/28/2000
• Status: Expired due to Term

• Current Assignee: Atrium Medical Corporation (Getinge AB)
• Original Assignee: Atrium Medical Corporation (Getinge AB)
• Inventors: Jordan, Gary A., Goodwin, Jonathan L., Gingras, Peter H.
• Primary Examiner(s): Bui, Vy Q.
• Application Number:
  US09/627,566
• Time in Patent Office: 1,551 Days
• Field of Search: 623/1--, 606/108, 606/191, 606/194, 606/198
• US Class Current: 623/1.13
• CPC Class Codes: A61F 2/86 Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
• 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 2002/072 Encapsulated stents, e.g. wire or whole stent embedded in lining
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61L 31/146 Porous materials, e.g. foams or sponges
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene

Abstract

A radially deployable covered stent that predictably and dependably expands to an increased diameter state at relatively low deployment pressures while concomitantly minimizing the risk of tearing of the stent covering during expansion. The stent covering includes an inner cover and an outer cover that are bonded together through and around the stent structure to cover the stent. The stent cover is constructed from expanded polytetrafluoroethylene (ePTFE) having a structure of nodes interconnected by fibrils. The stent covering has a radial thickness of at least about 0.008″ and an average internodal distance (IND) of at least about 100 microns when the stent is in the reduced diameter, unexpanded state. The covered stent deploys at an average deployment pressure of less than or equal to about 10 atm. A method for covering a stent structure according to the present invention includes placing a compression member in the form of a tubular sleeve over the outer cover and heating the compressed covered stent to bond the inner cover to the outer cover. An adhesive in the form of an aqueous dispersion of PTFE can be applied to either the inner cover or the outer cover to facilitate bonding of the inner cover to the outer cover.

Claims

1. A radially deployable stent comprising:

a stent structure having an inner surface and an outer surface, and

a stent covering comprising

an inner cover of biocompatible material positioned adjacent said inner surface of said stent structure, and

an outer cover of biocomparible material positioned adjacent said outer surface of said stent structure,

wherein at least one of said biocompatible material of said inner cover and said biocompatible material of said outer cover has a predetermined thickness and has an average internodal distance (IND) of greater than 100 microns to reduce a deployment pressure necessary to expand the stent To less than 10 atmospheres.

2. The stent of claim 1, wherein said inner cover is folded over said outer surface of said stent structure to form said outer cover.

3. The sent of claim 1, wherein, a first portion of said inner cover is folded over said outer surface of said stent structure and a second portion of said inner cover is folded over said first portion of said inner cover.

4. The stent of claim 1, wherein said inner cover and said outer cover extend substantially along the entire length of said stent structure.

5. The stent of claim 1, wherein said average internodal distance (IND) of each of the inner cover and the outer cover of greater than 110 microns.

6. The stent of claim 1, wherein said average internodal distance (IND) of each of the inner cover and the outer covet of greater than 135 microns.

7. A radially deployable stent comprising:

a stent structure having an inner surface and an outer surface, and

a stent covering comprising

an inner cover of biocompatible material positioned adjacent said in surface of said stent structure, and

an outer cover of biocompatible material positioned adjacent said outer surface of said stent structure,

wherein said stent covering has a radial thickness of at least about 0.008″ and

the average internodal distance (IND) of each of the inner cover and the outer cover of greater than 100 microns to reduce a deployment pressure necessary to expand the stent to less than 10 atmospheres.

8. The stent of claim 7, wherein said inner cover is folded over said outer surface of said stent structure to form said outer cover.

9. The stent of claim 8, wherein a first portion of said inner cover is folded over said outer surface of said stent structure and a second portion of said inner cover is folded over said first portion of said inner cover.

10. The stent of claim 7, wherein said inner cover and said outer cover extend substantially along the entire length of said steal structure.

12. The stent of claim 7, where said average internodal distance (IND) of each of the inner cover and the outer cover of greater than 135 microns.

11. The stent of clam 7, wherein sad avenge internodal distance (IND) of each of the inner cover and the outer cover of greater than 110 microns.