Variable flexibility stent

• US 6,287,336 B1
• Filed: 05/13/1999
• Issued: 09/11/2001
• Est. Priority Date: 10/16/1995
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Beyar, Mordechay, Globerman, Oren, Beyar, Rafael
• Primary Examiner(s): MILANO, MICHAEL J
• Application Number:
  US09/101,705
• Time in Patent Office: 852 Days
• Field of Search: 623/1.1, 623/1.15, 623/1.16, 623/1.3, 623/1.31
• US Class Current: 623/1.3
• 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 2/90 characterised by a net-like or mesh-like structure
• 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 2002/065 Y-shaped blood vessels
• 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 2002/9155 Adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91583 by a bridge, whereby at least one of its ends is connected along the length of a strut between two consecutive apices within a band
• CPC Class Codes: A61F 2250/0018 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0019 differing in hardness, e.g. Vickers, Shore, Brinell
• CPC Class Codes: A61F 2250/0029 differing in bending or flexure capacity
• CPC Class Codes: A61F 2250/0039 differing in diameter

Abstract

A stent (1) is provided for having variable flexibility and stiffness along its length. The stent (1) comprises portions (5, 7, 9, 11, 13, 15) of the stent having different bending and durability characteristics, and may be fabricated, using any of a variety of methods out of any of a variety of materials.

Claims

1. A stent comprising a plurality of expandable annular members;

and a plurality of cross members having ends, the ends of each cross member being attached to an annular member at a point in common with a longitudinally adjacent cross member;

the cross members differing in their relative rigidity and positioned so as to vary the bending flexibility of the stent along its length.

2. The stent of claim 1 comprising a plurality of dimensionally variable members.

3. The stent of claim 1 comprising a plurality of compositionally variable members.

4. The stent of claim 1, wherein the cross members positioned at the ends of the stent are less rigid than the cross members positioned at the center of the stent, such that the bending flexibility of the stent is greater at the ends of the stent than in the middle of the stent.

5. The stent of claim 1 fabricated from at least one material selected from the group consisting of stainless steel, nitinol, titanium, tantalum, and other metals and metal alloys.

6. The stent of claim 1, which has been fabricated using a method selected from the group consisting of forming, stamping, and etching.

7. The stent of claim 1, which has been fabricated using a film contact imaging method.

8. The stent of claim 1, which has been fabricated using a laser cutting method.

9. The stent of claim 1, wherein both the expandable annular members and the cross members differ in their relative rigidities.

10. The stent of claim 1 comprising a plurality of distal ends and a middle portion, wherein the bending flexibility of the stent is greater at the distal ends than at the middle portion.