METHODS FOR MAKING AN ENCAPSULATED STENT AND INTRALUMINAL DELIVERY THEREOF

• US 20090125092A1
• Filed: 11/17/2008
• Published: 05/14/2009
• Est. Priority Date: 03/10/1995
• Status: Active Grant

• Current Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Banas, Christopher E., McCrea, Brendan J., Edwin, Tarun J.
• Granted Patent: US 7,939,000 B2
• Time in Patent Office: Days
• US Class Current: 623/1.110
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61F 2/07 Stent-grafts
• 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 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2002/072 Encapsulated stents, e.g. wire or whole stent embedded in lining
• CPC Class Codes: A61L 2400/16 Materials with shape-memory or superelastic properties
• CPC Class Codes: A61L 27/507 for artificial blood vessels apparatus for applying cells on a blood vessel prosthesis A61F2/062
• CPC Class Codes: A61L 31/048 obtained by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: B29C 55/005 characterised by the choice of materials
• CPC Class Codes: B29C 55/22 of tubes B29C61/08 takes precedence
• CPC Class Codes: B29K 2027/18 PTFE, i.e. polytetrafluorethene , e.g. ePTFE, i.e. expanded polytetrafluorethene
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene
• CPC Class Codes: Y10S 623/901 Method of manufacturing prosthetic device

Abstract

A method for making an encapsulated stent includes providing a first seamless unsintered ePTFE tube, providing a second seamless sintered ePTFE tube, positioning a self-expanding stent between the first and second ePTFE tubes to form an assembly, and joining the first ePTFE tube to the second ePTFE tube through openings in a wall of the stent by applying first pressure, and then heat, to the assembly.

Claims

1. A method for making an encapsulated stent, comprising:

providing a first seamless unsintered ePTFE tube;

providing a second seamless sintered ePTFE tube;

positioning a self-expanding stent between the first and second ePTFE tubes to form an assembly; and

joining the first ePTFE tube to the second ePTFE tube through openings in a wall of the stent by applying first pressure, and then heat, to the assembly.

2. The method according to claim 1, wherein the first and second ePTFE tubes, characterized by a node-fibril microstructure, contain fibrils having a parallel orientation with respect to a longitudinal axis thereof.

3. The method according to claim 1, further comprising the step of disposing an interlayer member between the first and second ePTFE tubes prior to the applying step.

4. The method according to claim 3, wherein the interlayer member comprises an unsintered film of ePTFE, wherein the step of disposing comprises wrapping the ePTFE film about an end of the stent.

5. The method according to claim 3, wherein the interlayer member comprises a tubular unsintered ePTFE member, wherein the step of disposing comprises positioning the ePTFE member in coaxial relation with an end of the stent.

6. The method according to claim 5, wherein the tubular unsintered ePTFE member has a node-fibril microstructure including fibrils having a generally uniaxial orientation, the step of disposing comprising orienting the fibrils parallel to a longitudinal axis of the assembly.

7. The method according to claim 1, further comprising:

placing the first seamless unsintered ePTFE tube over a mandrel; and

concentrically engaging the second seamless sintered ePTFE tube over the first ePTFE tube after placing the first ePTFE tube over the mandrel, the positioning step including manipulating the stent from a first diameter to a second diameter smaller than the first diameter and inserting the stent between the first ePTFE tube and second ePTFE tube to form the assembly, the joined first ePTFE tube and second ePTFE tube applying a constraining force on the stent, following the joining step, to prevent expansion of the stent from the second diameter to the first diameter.

8. The method according to claim 7, wherein the placing step further comprises wrapping the ends of the ePTFE tube with strips of tape to retain the position of the ePTFE tube on the mandrel.

9. The method according to claim 7, wherein the stent comprises a shape memory material, the positioning step including cooling the stent to a temperature below its martensitic transformation temperature prior to manipulating to the second diameter.

10. The method according to claim 7, wherein the stent comprises a shape memory material, the positioning step including maintaining the temperature of the stent above its martensitic transformation temperature during the manipulating to the second diameter.

11. A method for deploying the encapsulated stent made according to the method of claim 7, comprising the steps of:

delivering the encapsulated stent to a predetermined site within a body lumen;

applying a first pressure sufficient to overcome the constraining force to an inner surface of the encapsulated stent at the predetermined site; and

applying a second pressure to an inner surface of the encapsulated stent following expansion to about the stent first diameter, the second pressure sufficient to expand the assembly to a third diameter larger than the first diameter.

12. The method according to claim 1, the stent having a first diameter and a second diameter smaller than the first diameter, the positioning step performed at the stent first diameter, further comprising the step of manipulating the assembly to the stent second diameter, following the joining step, and inserting the assembly into a delivery sheath that applies a constraining force on the assembly to prevent expansion thereof.

13. The method according to claim 12, wherein the stent comprises a shape memory material, the manipulating step including cooling the stent to a temperature below its martensitic transformation temperature.

14. The method according to claim 12, wherein the stent comprises a shape memory material, the manipulating step including maintaining the temperature of the stent above its martensitic transformation temperature.

15. A method for deploying the encapsulated stent made according to the method of claim 12, comprising the steps of:

delivering the encapsulated stent to a predetermined site within a body lumen;

removing the constraining force from the encapsulated stent at the predetermined site; and

applying pressure to the encapsulated stent following expansion to about the stent first diameter, the pressure sufficient to expand the assembly to a third diameter larger than the first diameter.