Intravascular stent having high fatigue performance

• US 10,575,973 B2
• Filed: 04/11/2018
• Issued: 03/03/2020
• Est. Priority Date: 04/11/2018
• Status: Active Grant

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Inventors: Ta, Diem Uyen, Eswaran, Senthil Kumar
• Primary Examiner(s): Dukert, Brian A
• Assistant Examiner(s): Zimmerman, Rebecca Lynee
• Application Number:
  US15/950,486
• Publication Number:
  US 20190314174A1
• Time in Patent Office: 692 Days
• 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 2/915 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 2002/828 Means for connecting a plurality of stents allowing flexibility of the whole structure
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2230/0056 W-shaped, e.g. M-shaped, sigma-shaped
• CPC Class Codes: A61F 2230/006 Y-shaped
• CPC Class Codes: A61F 2230/0069 cylindrical

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 links. A Y-shaped member comprised of a link and a U-shaped member has relief dimples formed in the curved portion of a valley to reduce localized stress and thereby reduce fatigue failure that can lead to link structure failure.

Claims

1. A longitudinally flexible stent for implanting in a body lumen, comprising:

a first cylindrical ring, a second cylindrical ring, a third cylindrical ring, up to an Nth cylindrical ring, the cylindrical rings being generally independently expandable in the radial direction and generally aligned on a common longitudinal axis;

each of the cylindrical rings having an undulating pattern of peaks and valleys, the undulating pattern of each of the cylindrical rings being in phase with the undulating pattern of each of the adjacent cylindrical rings;

each of the cylindrical rings being interconnected by links to one of the adjacent cylindrical rings so that the cylindrical rings form a longitudinally flexible stent; and

a Y-shaped member is formed by one of the links connecting to a curved portion of valley, a first relief dimple and a second relief dimple are formed in the curved portion of the valley and wherein the first dimple and the second dimple have a radius R3 in the range consisting of 0.00197 inch to 0.00276 inch.

2. The stent of claim 1, wherein a reverse radius R4 is located on either side of the first relief dimple and the second relief dimple thereby providing a smooth transition of the relief dimples on the curved portion of the valley.

3. The stent of claim 2, wherein the reversed radius R4 is 0.000079 inch.

4. The stent of claim 1, wherein the distance between adjacent cylindrical rings is less than the width of either a single peak or a single valley.

5. The stent of claim 1, wherein each of the cylindrical rings includes at least three peaks and three valleys.

6. The stent of claim 1, wherein the peaks and valleys have a U-shaped configuration.

7. The stent of claim 1, wherein the stent is formed from a polymer material.

8. The stent of claim 1, wherein the stent is formed from a biodegradable material.