Polymer link hybrid stent

• US 20040127970A1
• Filed: 12/30/2002
• Published: 07/01/2004
• Est. Priority Date: 12/30/2002
• Status: Active Grant

• Current Assignee: Advanced Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Advanced Cardiovascular Systems Incorporated (Abbott Laboratories)
• Inventors: Callol, Joseph R., Hong, James, Saunders, Richard J.
• Granted Patent: US 7,455,687 B2
• Time in Patent Office: Days
• US Class Current: 623/1.15
• 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 2002/072 Encapsulated stents, e.g. wire or whole stent embedded in lining
• 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 2002/91591 Locking connectors, e.g. using male-female connections
• CPC Class Codes: A61F 2220/0025 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2250/0014 having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis
• CPC Class Codes: A61L 31/022 Metals or alloys
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61L 31/18 Materials at least partially X-ray or laser opaque

Abstract

The present invention is directed to an expandable polymer link hybrid stent for implantation in a body lumen, such as a coronary artery along with a method of making the stent. The stent generally includes a series of metallic cylindrical rings longitudinally aligned on a common axis of the stent and interconnected by a series of polymeric links. The polymer links are formed by applying polymer layers between the rings and laser ablating the excess material. The polymeric material forming the polymeric links, provides longitudinal and flexural flexibility to the stent while maintaining sufficient column strength to space the cylindrical rings along the longitudinal axis. The metallic material forming the rings provides the necessary radial stiffness.

Claims

1. An intravascular stent, comprising:

a plurality of metallic cylindrical rings with a first delivery diameter and a second implanted diameter, the rings being expandable in a radial direction and aligned along a longitudinal axis of the stent;

a plurality of polymeric links positioned between the plurality of cylindrical rings; and

at least some of the metallic rings being embedded in a polymer layer.

2. The stent of claim 1, wherein the polymer layer includes a ring pattern corresponding to the at least some of the metallic rings.

3. The stent of claim 1, wherein the polymer layer has a radial thickness in the range of about 0.003 to about 0.010 inch.

4. The stent of claim 3, wherein the polymer layer is substantially the same radial thickness as a radial thickness of the at least some of the cylindrical rings.

5. The stent of claim 3, wherein the polymer layer radial thickness is greater than a radial thickness of the at least some of the cylindrical rings.

6. The stent of claim 1, wherein a polymer coating is disposed around the at least some of the metallic rings.

7. The stent of claim 1, wherein the polymer coating has a radial thickness in the range of about 0.002 to about 0.005 inch.

8. The stent of claim 1, wherein the links are formed from the polymer layer and the polymer coating

9. The stent of claim 1, wherein the polymeric material forming the links is taken from the group of polymers consisting of polyurethanes, polyetherurethanes, polyesterurethanes, silicone, thermoplastic elastomer (C-flex), polyether-amide thermoplastic elastomer (Pebax), fluoroelastomers, fluorosilicone elastomer, poly (glycerol-sebacate) (PGS), styrene-butadiene rubber, butadiene-styrene rubber, polyisoprene, neoprene (polychloroprene), ethylene-propylene elastomer, chlorosulfonated polyethylene elastomer, butyl rubber, polysulfide elastomer, polyacrylate elastomer, nitrile, rubber, a family of elastomers composed of styrene, ethylene, propylene, aliphatic polycarbonate polyurethane, polymers augmented with antioxidants, polymers augmented with image enhancing materials, polymers having a proton (H+) core, polymers augmented with protons (H+), butadiene and isoprene (Kraton) and polyester thermoplastic elastomer (Hytrel).

10. The stent of claim 1, wherein the metallic material forming the cylindrical rings is taken from the group of materials consisting of stainless steel, titanium, tantalum, nickel-titanium, cobalt-chromium, gold, palladium, platinum and iradium.

11. The stent of claim 1, wherein the rings and links are coated with a therapeutic drug.

12. The stent of claim 1, wherein the stent is bio-compatible.

13. The stent of claim 1, wherein the stent is non-biodegradable.

14. The stent of claim 1, wherein a plurality of polymeric links include a material therein to enhance the radiopacity of the stent.

15. The stent of claim 1, wherein a plurality of polymeric links are substantially translucent.

16. The stent of claim 1, wherein the cylindrical rings include a material therein to enhance the radiopacity of the stent.

17. A method for forming an intravascular stent, comprising:

forming a plurality of metallic cylindrical rings having undulations comprising a plurality of peaks and valleys;

forming a plurality of polymeric links;

attaching the polymeric links between adjacent cylindrical rings; and

applying a polymeric coating over the rings and the links to form the stent.

18. A method for forming an intravascular stent, comprising:

forming a plurality of metallic cylindrical rings;

coating a mandrel with a first series of polymeric layers;

forming a plurality of cylindrical ring cavities in the polymeric layers;

embedding the cylindrical rings into the cylindrical ring cavities;

coating the cylindrical rings and first polymeric layers with a second series of polymeric coatings;

ablating the first polymeric layers and the second polymeric coatings to form a stent.

19. The method of claim 18, wherein forming a plurality of metallic cylindrical rings comprises laser cutting the cylindrical rings.

20. The method of claim 18, wherein the cylindrical rings cavities are sized to conform with the cylindrical rings.

21. The method of claim 20, wherein a laser forms the cylindrical ring cavities in the first polymeric layers.

22. The method of claim 18, wherein the first series of polymeric layers is applied in a thickness approximately equal to the thickness of the cylindrical rings.

23. The method of claim 18, wherein the mandrel incorporates laser registration features.

24. The method of claim 23, wherein the coated mandrel is removed from a laser rotary fixture with its position registered in a control memory after forming a plurality of cylindrical ring cavities.

25. The method of claim 24, wherein the coated mandrel is placed back into the laser rotary fixture after coating the cylindrical rings and first polymeric layers with a second series of polymeric coatings.

26. The method of claim 25, wherein the coated mandrel is cured after coating the cylindrical rings and polymeric layers with a second series of polymeric coatings.

27. The method of claim 18, wherein forming a plurality of cylindrical rings cavities comprises laser cutting the cavities into the polymeric layers so that at least of some of the first polymer layers remains on the mandrel

28. The method of claim 18, wherein the laser is any of a CO2 laser, an Eximer laser, or solid state laser, picoseocond laser, or femtosectond laser.