SELF-EXPANDABLE STENT WITH A CONSTRICTIVE COATING AND METHOD OF USE

• US 20090204196A1
• Filed: 02/10/2009
• Published: 08/13/2009
• Est. Priority Date: 02/11/2008
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Inventors: WEBER, Jan
• Granted Patent: US 8,915,951 B2
• Time in Patent Office: Days
• US Class Current: 623/1.200
• CPC Class Codes: A61B 2017/32004 having a laterally movable cutting member at its most distal end which remains within the contours of said end
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/97 the outer sleeve being splittable
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61L 31/14 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials

Abstract

The present invention provides a system and method for providing a coating on a self-expandable medical device, such as a stent, while avoiding the issues relating to coating damage from the delivery sheath during loading and deployment. In one embodiment, the present invention comprises a constrictive coating that acts as a constrictive sheath for the stent. A cutting mechanism is mounted on the end of the delivery tube such that when the stent with the constrictive coating exits the delivery tube, the constrictive coating is cut. This releases the constriction retaining the sheath, and the stent self-expands, pressing the cut portions of the coating against the lumen wall.

Claims

1. A system for deploying a self-expandable medical device with a coating, comprising:

a self-expandable medical device;

a constrictive coating on an outer surface of the medical device;

a delivery tube having an opening at a distal end of the tube, the self-expandable medical device and the constrictive coating loaded inside the delivery tube; and

at least one cutting mechanism mounted at the distal end of the sheath and adapted to cut the constrictive coating as the medical device exits the delivery tube through the opening at the distal end of the delivery tube.

2. The system of claim 1, wherein the cutting mechanism comprises a plurality of blades mounted on an annular inner surface.

3. The system of claim 2, wherein the plurality of blades are evenly spaced around a circumference of the delivery tube.

4. The system of claim 2, wherein the plurality of blades are unevenly distributed around a circumference of the delivery tube.

5. The system of claim 2, wherein the plurality of blades comprises two to eight blades.

6. The system of claim 2, wherein each blade includes a cutting edge that extends into a center of the delivery tube and faces proximally.

7. The system of claim 2, wherein the cutting mechanism further comprises a ring on which the plurality of blades are mounted.

8. The system of claim 1, wherein the constrictive coating is made of a material that keeps the medical device from expanding until the constrictive coating is cut by the cutting mechanism.

9. The system of claim 8, wherein the material comprises polyurethane, cellulose, or a combination thereof.

10. The system of claim 1, wherein the constrictive coating further comprises a biocompatible metal.

11. The system of claim 10, wherein the biocompatible metal is a shape memory metal.

12. The system of claim 11, wherein the constrictive coating initially comprises two cylindrical sections.

13. The system of claim 12, wherein the two cylindrical sections are of approximately equal lengths.

14. The system of claim 11, wherein the constrictive coating comprises a plurality of rings, each ring having a proximal edge and a distal edge.

15. The system of claim 14, wherein the proximal edge of each ring is attached to the medical device.

16. The system of claim 1, wherein the constrictive coating is attached to the medical device.

17. The system of claim 1, wherein the constrictive coating is not attached to the medical device.

18. The system of claim 1, wherein the medical device is a stent.

19. A method of deploying a self-expandable medical device with a coating, comprising the steps of:

providing a self-expandable medical device with a constrictive coating around the medical device;

inserting the medical device with the constrictive coating into a delivery tube, the delivery tube comprising an opening at a distal end of the tube;

mounting at least one cutting mechanism on the distal end of the tube;

inserting the delivery tube containing the medical device and constrictive coating into a lumen of a patient; and

deploying the medical device with the constrictive coating from the opening at the distal end of the delivery, thereby cutting the constrictive coating on the medical device as the medical device passes by the cutting mechanism, and allowing the medical device to self-expand as it exits from the delivery tube.

20. The method of claim 19, wherein the constrictive coating comprises a shape memory material and the body lumen includes a bifurcation, and wherein when the constrictive coating is cut, cut portions of the constrictive coating change toward their unconstrained curved state to substantially conform to the walls of the bifurcation as the medical device expands.

21. The method of claim 19, wherein the step of mounting at least one cutting mechanism takes place after the medical device with the constrictive coating is inserted into the delivery tube.

22. The method of claim 19, wherein the step of mounting at least one cutting mechanism takes place before the medical device with the constrictive coating is inserted into the delivery tube.

23. The method of claim 19, wherein the medical device is a stent.