Drug-eluting stent cover and method of use

• US 20060271165A1
• Filed: 08/01/2006
• Published: 11/30/2006
• Est. Priority Date: 12/30/2002
• Status: Active Grant

• Current Assignee: James Jacobs, Jon Becker, Philip S. Yip, Syed Hossainy, Timothy A. Limon
• Original Assignee: James Jacobs, Jon Becker, Philip S. Yip, Syed Hossainy, Timothy A. Limon
• Inventors: Hossainy, Syed, Jacobs, James, Limon, Timothy A., Yip, Philip S., Becker, Jon
• Granted Patent: US 7,413,574 B2
• Time in Patent Office: Days
• US Class Current: 623/1.160
• CPC Class Codes: A61F 2/90 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 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91508 the meander having a difference in amplitude along the band
• CPC Class Codes: A61F 2002/91516 the meander having a change in frequency along the band
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61F 2250/0036 differing in thickness
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61F 2250/0071 breakable or frangible
• CPC Class Codes: Y10S 623/903 Blood vessel

Abstract

An intravascular stent includes an eluting sheath fabricated from a mesh for controlled release of therapeutic drugs and for delivery of the therapeutic drugs in localized drug therapy in a blood vessel. The eluting sheath is attached to at least a portion of an outside surface area of the stent structure and is fabricated from a mesh designed to neck down in response to a radially outward directed force resulting in the uniform expansion of the stent. The eluting sheath can be loaded with at least one therapeutic drug for the release thereof at a treatment site to facilitate repair of a damaged vessel. The stent has a high degree of flexibility in the longitudinal direction, yet has adequate vessel wall coverage and radial strength sufficient to hold open an artery or other body lumen.

Claims

1. A method for treating a body lumen with a drug-delivery stent assembly, comprising:

providing a pattern of struts interconnected to form a stent structure that contacts the walls of a body lumen to maintain the patency of the lumen;

attaching a stent cover having a delivery sheath fabricated from a mesh to at least a portion of an outside surface area of the stent structure to form the stent assembly;

loading the delivery sheath with at least one therapeutic drug for the release thereof in the body lumen;

intraluminally delivering the stent assembly in the body lumen;

providing a radially outward directed force to the stent cover; and

plastically deforming at least a portion of the stent cover in response to the radially outward directed force so that the deformed portions neck down or break thereby providing less resistance to expansion of the stent assembly.

2. The method of claim 1, wherein the radially outward force is delivered to the stent structure by inflation of an expandable member on a catheter.

3. The method of claim 1, wherein the radially outward directed force is provided by a self-expanding stent structure.

4. The method of claim 1, wherein the therapeutic agent is selected from the group consisting essentially of antiplatelets, anticoagulants, antifibrins, antithrombins, anti-inflammatories and antiproliferatives.

5. The method of claim 1, wherein the therapeutic agent loading range is about 30 to 60 percent by weight.

6. The method of claim 1, wherein the stent cover is attached to the stent structure at a stent structure distal end and a stent proximal end so that the cover is free to stretch in a mid-cover section as the stent expands.

7. The method of claim 1, wherein the mesh stent cover is comprised of a polymer.

8. The method of claim 7, wherein the polymeric stent mesh cover is fabricated from a polymeric material selected from the group consisting of PMMA, EVAL, PBMA, PGA, PEG, HA, PEA, PGS and PLLA.

9. The method of claim 1, wherein the stent includes a pattern of struts having a plurality of flexible cylindrical rings being expandable in a radial direction, each of the rings having a first delivery diameter and a second implanted diameter and being aligned on a common longitudinal axis.

10. The method of claim 1, wherein the stent structure is formed of a metallic material.

11. The method of claim 10, wherein the metallic material forming the stent structure is taken from the group consisting essentially of stainless steel, platinum, titanium, tantalum, nickel-titanium, cobalt chromium, and alloys thereof.

12. The method of claim 1, wherein the radially outward directed force is provided by the stent expanding from a first delivery diameter to a second implanted diameter.

13. The method of claim 1, wherein the mesh stent cover is prepared in situ by weaving.

14. The method of claim 1, wherein the mesh stent cover is braided on the stent.

15. The method of claim 1, wherein the mesh stent cover is configured to neck down in response to a stent structure expansion of at least 400 percent.

16. The method of claim 1, wherein the mesh cover is attached to the stent structure by an adhesive.

17. The method of claim 1, wherein the mesh cover is attached to the stent structure by laser bonding.

18. The method of claim 1, wherein upon expansion of the stent structure, the agent loaded polymeric mesh stent cover plastically deforms so that the agent loaded cover is held against the blood vessel wall by the stent structure.

19. The method of claim 1, wherein the stent cover is made using at least one polymeric process consisting of extrusion, injection molding, laser cutting, braiding and slip casting.

20. The stent system of claim 1, wherein the stent cover includes at least one additional layer of polymeric material as a barrier layer to further control delivery of the therapeutic agent at the treatment site.