RADIOPAQUE NITINOL ALLOYS FOR MEDICAL DEVICES

• US 20080027532A1
• Filed: 10/10/2007
• Published: 01/31/2008
• Est. Priority Date: 12/27/2000
• Status: Active Grant

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories)
• Inventors: BOYLAN, John, Cox, Daniel
• Granted Patent: US 7,918,011 B2
• Time in Patent Office: Days
• US Class Current: 623/1.18
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91516 the meander having a change in frequency along the band
• CPC Class Codes: A61F 2002/91525 within the whole structure different bands showing different meander characteristics, e.g. frequency or amplitude
• 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 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61L 2400/16 Materials with shape-memory or superelastic properties
• CPC Class Codes: A61L 31/022 Metals or alloys
• CPC Class Codes: A61L 31/18 Materials at least partially X-ray or laser opaque
• CPC Class Codes: C22C 19/00 Alloys based on nickel or cobalt
• CPC Class Codes: Y10S 623/901 Method of manufacturing prosthetic device
• CPC Class Codes: Y10T 29/49995 Shaping one-piece blank by removing material

Abstract

A radiopaque nitinol medical device such as a stent for use with or implantation in a body lumen is disclosed. The stent is made from a superelastic alloy such as nickel-titanium or nitinol, and includes a ternary element selected from the group of chemical elements consisting of iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, or hafnium. The added ternary element improves the radiopacity of the nitinol stent comparable to that of a stainless steel stent of the same and strut pattern coated with a thin layer of gold. The nitinol stent has improved radioplacity yet retains its superelastic and shape memory behavior and further maintains a thin strut/wall thickness for high flexibility.

Claims

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15. A method for providing a radiopaque medical device, comprising:

providing a self-expanding tublar body made form a superelastic nickel-titanium alloy, wherein the nickel-titanium alloy includes a radiopacity enhancing ternary element selected from the group consisting of palladium platinum such that an atomic percent of palladium is greater than 3 percent and less than or equal to 20 percent and an atomic percent of platinum is greater than 3 percent and less than or equal to 15 percent;

cutting a strut pattern into the tubular body;

heating treating the tubular body; and

wherein the medical device exhibits a level of radiopacity greater than the nickel-titanium alloy without the radiopacity enhancing ternary element.

16. A method for providing radiopaque tubing, comprising:

forming a tubular-shaped body having a thin wall, wherein the body includes a superelastic nickel-titanium alloy and the alloy further includes a ternary element selected from the group of chemical elements consisting of iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, and hafnium;

wherein the step of providing a tubular-shaped body includes melting nickel, titanium, and the ternary element, cooling to form an alloy ingot, hot forming the alloy ingot, forming the alloy ingot into a cylinder, drilling the cylinder to form tubing, drawing the tubing, and annealing the tubing.

17. The method of claim 16, wherein the atomic percent of platinum is greater than 3 and less than or equal to 15.

18. The method of claim 16, wherein the atomic percent of palladium is greater than 3 and less than or equal to 20.