Cylindrically-shaped balloon-expandable stent

• US 6,736,843 B1
• Filed: 04/02/1998
• Issued: 05/18/2004
• Est. Priority Date: 07/25/1994
• Status: Expired due to Fees

• Current Assignee: Advanced Cardiovascular Systems Incorporated
• Original Assignee: Advanced Cardiovascular Systems Incorporated
• Inventors: Fariabi, Sepehr
• Primary Examiner(s): Prebilic, Paul B.
• Application Number:
  US09/054,320
• Time in Patent Office: 2,238 Days
• Field of Search: 623/1, 623/12, 623/1.15, 623/1.16, 623/1.17, 623/903, 606/198
• US Class Current: 623/1.16
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2210/0019 operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation
• CPC Class Codes: A61M 2025/09083 having a coil around a core
• CPC Class Codes: A61M 25/0009 Making of catheters or other medical or surgical tubes
• CPC Class Codes: A61M 25/0013 Weakening parts of a catheter tubing, e.g. by making cuts in the tube or reducing thickness of a layer at one point to adjust the flexibility
• CPC Class Codes: A61M 25/09 Guide wires
• CPC Class Codes: Y10T 29/49995 Shaping one-piece blank by removing material

Abstract

This invention is directed to an intracorporeal device formed of a high strength Co—Ni—Cr alloy and is particularly suitable for forming a composite product with a pseudoelastic member formed of NiTi alloy. Suitable intracorporeal products include guidewires and stents. The high strength alloy consists essentially of about 28 to about 65% cobalt, about 2 to about 40% nickel, about 5 to about 35% chromium, up to about 12% molybdenum, up to about 20% tungsten, up to about 20% iron and the balance inconsequential amounts of impurities and other alloying constituents, with a preferred alloy composition including about 30 to about 45% cobalt, about 25 to about 37% nickel, about 15 to about 25% chromium and about 5 to about 15% molybdenum. Intravascular devices such as guidewires, stents and the like can be formed of this high strength Co—Ni—Cr alloy.

Claims

1. A cylindrically shaped balloon-expandable stent configured for use in a coronary artery, comprising:

a plurality of independently expandable and interconnected cylindrical elements formed of an alloy containing cobalt, chromium, molybdenum, and nickel and generally aligned along a common longitudinal axis; and

the stent has a first low profile configuration for delivery and a second radially expandable configuration and is plastically deformable from the first low profile delivery configuration to the second radially expanded configuration, the second radially expanded configuration having a diameter suitable to hold open the coronary artery,

wherein the cylindrical elements of the stent have an clasticity insufficient to allow expansion from the first low profile delivery configuration to the second radially expanded configuration without plastic deformation so as to be permanent, and the cylindrical elements having an undulating component, wherein the undulating component has an electrochemically polished metallic surface;

the stent further comprising a biocompatible coating on the electrochemically polished metallic surface of the cylindrical elements.

2. The stent of claim 1, wherein the alloy contains about 28 to about 65 weight percent cobalt, about 5 to about 35 weight percent chromium, about 2 to about 40 weight percent nickel.

3. The stent of claim 2, wherein the alloy further contains molybdenum up to about 15 weight percent.

4. The stent of claim 1, wherein the alloy further contains molybdenum up to about 15 weight percent.

5. The stent of claim 1, wherein at least one of the cylindrical elements has an undulating component out of phase with the undulating component of at least another one of the cylindrical elements.

6. The stent of claim 1, wherein the cross-section of the undulating component of the cylindrical element has an aspect ratio of about one to one.

7. The stent of claim 1, wherein the cross-section of the undulating component of the cylindrical element has a height-to-width aspect ratio of about two-to-one.