Expandable stents and method for making same

• US 5,766,238 A
• Filed: 03/24/1997
• Issued: 06/16/1998
• Est. Priority Date: 10/28/1991
• Status: Expired due to Term

• Current Assignee: Advanced Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Advanced Cardiovascular Systems Incorporated (Abbott Laboratories)
• Inventors: Lau, Lilip, Frantzen, John J., Hartigan, William M.
• Primary Examiner(s): BRITTINGHAM, DEBRA
• Application Number:
  US08/823,434
• Time in Patent Office: 449 Days
• Field of Search: 623/1, 623/11, 623/12, 606/194, 606/195, 606/198, 600/36, 156/654.1, 156/643.1, 156/644.1, 156/656.1, 156/659.11, 216/41
• US Class Current: 600/36
• CPC Class Codes: A61F 2/848 having means for fixation to the vessel wall, e.g. barbs
• CPC Class Codes: A61F 2/86 Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2/89 the wire-like elements comprising two or more adjacent rings flexibly connected by separate members
• 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 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/9155 Adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• 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 2025/1081 having sheaths or the like for covering the balloon but not forming a permanent part of the balloon, e.g. retractable, dissolvable or tearable sheaths
• CPC Class Codes: C23F 1/02 Local etching
• CPC Class Codes: C23F 1/04 Chemical milling
• CPC Class Codes: Y10S 623/901 Method of manufacturing prosthetic device
• CPC Class Codes: Y10S 623/903 Blood vessel
• CPC Class Codes: Y10S 623/921 Blood vessel
• CPC Class Codes: Y10T 29/49995 Shaping one-piece blank by removing material

Abstract

The invention is directed to an expandable stent for implantation in a body lumen, such as an artery, and a method for making it from a single length of tubing. The stent consists of a plurality of radially expandable cylindrical elements generally aligned on a common axis and interconnected by one or more interconnective elements. The individual radially expandable cylindrical elements consist of ribbon-like material disposed in an undulating pattern. Portions of the expanded stent project outwardly into engagement with the vessel wall to more securely attach the stent.

Claims

1. A method of chemically etching a serpentine pattern on a metallic member to form an intravascular stent, comprising:

applying a coating resistive to chemical etching to a metallic surface of the metallic member;

selectively removing portions of the resistive coating form the metallic surface thereby providing exposed portions of the metallic surface and protected portions of the metallic surface, the protected portions of the metallic surface forming the serpentine pattern;

exposing the metallic surface to a chemical etchant solution thereby removing all of the exposed portions of the metallic surface; and

means for removing the resistive coating and polishing the metal surface to provide a uniform surface finish thereby forming the serpentine pattern of the stent.

2. The method of claim 1, wherein the step of removing the resistive coating is performed by a laser.

3. The method of claim 2, wherein the laser is operated in a pulsed mode for removing the resistive coating.

4. The method of claim 3, wherein the pulse length time is about 0.3 mS.

5. The method of claim 2, wherein the laser is operated so that it removes only the resistive coating, and not the metallic surface of the metallic member.

6. The method of claim 1, wherein the metallic surface of the metallic member, prior to the step of applying the resistive coating, is flat.

7. The method of claim 1, wherein the metallic surface, prior to the application of the resistive coating, is curved.

8. The method of claim 1, wherein the means for removing the resistive coating and polishing the metallic surface includes electrochemically polishing the metallic member in an acidic aqueous solution.