Guide wire and stent

• US 8,568,470 B2
• Filed: 09/23/2011
• Issued: 10/29/2013
• Est. Priority Date: 05/09/2007
• Status: Active Grant

• Current Assignee: Terumo Kabushiki Kaisha
• Original Assignee: Japan Science & Technology Trading Co. Limited, Terumo Kabushiki Kaisha
• Inventors: Ishida, Kiyohito, Yamauchi, Kiyoshi, Kainuma, Ryosuke, Sutou, Yuji, Omori, Toshihiro, Tanaka, Yuuki, Murayama, Hiraku, Souba, Ryouichi
• Primary Examiner(s): STEWART, JASON-DENNIS NEILKEN
• Application Number:
  US13/243,651
• Publication Number:
  US 20120016463A1
• Time in Patent Office: 767 Days
• Field of Search: 623/1.15, 623/1.18, 623/19
• US Class Current: 623/1.15
• 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 2002/9155 Adjacent bands being connected to each other
• CPC Class Codes: A61F 2230/005 Rosette-shaped, e.g. star-shaped
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61F 2230/008 paraboloidal
• 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 31/10 Macromolecular materials
• CPC Class Codes: A61M 2025/09091 where a sheath surrounds the coil at the distal part
• CPC Class Codes: A61M 2025/0915 having features for changing the stiffness
• CPC Class Codes: A61M 25/09 Guide wires
• CPC Class Codes: Y10T 29/4998 Combined manufacture including applying or shaping of fluent material
• CPC Class Codes: Y10T 29/49995 Shaping one-piece blank by removing material

Abstract

A guide wire includes a distal core member made of a ferrous alloy which has shape memory properties and superelasticity. The ferrous alloy preferably includes substantially two phases, and has a difference of 100° C. or less between an Af point and an Ms point in a thermal hysteresis of martensitic transformation and reverse transformation. The guide wire may include a proximal core member made of an iron-containing alloy and having a higher modulus of elasticity than the distal core member. The two core members may be joined together by welding to form a core of the guide wire.

Claims

1. A stent comprising:

a stent body;

wherein said stent body is formed from a ferrous alloy which has shape memory properties and superelasticity, said ferrous alloy including a substantially dual phase structure defined by a γ

phase and a γ

′

phase having a difference of 100°

C. or less between a reverse transformation finish temperature and a martensitic transformation start temperature in a thermal hysteresis of martensitic transformation and reverse transformation, the ferrous alloy including from 30 to 50% by mass of iron and from 0.001 to 1% by mass of boron;

wherein said ferrous alloy further includes from 7.8 to 8.0% by mass of tantalum; and

wherein the stent is configured for insertion into a living body.

2. The stent of claim 1, wherein the stent body includes a plurality of undulating bends provided in an axial direction.

3. The stent of claim 1, wherein the stent body is composed of braided wire.

4. The stent of claim 1, wherein the stent body has a wall thickness of 0.2 mm or less.

5. The stent of claim 4, wherein the stent body has a wall thickness of 0.10 mm or less.

6. The stent of claim 1, wherein the ferrous alloy includes from 38.8 to 46.4% by mass of iron.

7. The stent of claim 1, wherein an abundance of a specific crystal orientation in a working direction of a worked portion for the ferrous alloy is at least 2.0.

8. The stent of claim 1, wherein the ferrous alloy includes from 0.002 to 0.7% by mass of boron.

9. The stent of claim 1, wherein the ferrous alloy includes from 0.006 to 0.01% by mass of boron.

10. The stent of claim 1, wherein the stent body includes a plurality of undulating rings united by partly shared linear segments configured to exhibit a uniform expansion retaining force, each said undulating ring including a plurality of first-side bends and a plurality of second-side bends, and said plurality of linear segments include a plurality of short linear segments and a plurality of long linear segments.

11. A stent comprising:

a stent body comprising a ferrous alloy having shape memory properties and superelasticity, said ferrous alloy including a two phase structure defined by a γ

phase and a γ

′

phase having a difference of 100°

C. or less between a reverse transformation finish temperature and a martensitic transformation start temperature in a thermal hysteresis of martensitic transformation and reverse transformation;

the ferrous alloy comprising a composition which includes from 25 to 35% by mass of nickel, from 10 to 30% by mass of cobalt, and from 2 to 8% by mass of aluminum, the composition including a total of from 1 to 20% by mass of at least one selected from the group consisting of from 1 to 5% by mass of titanium, from 2 to 10% by mass of niobium, from 3 to 20% by mass of tantalum, and the balance being from 35 to 50% by mass of iron and inadvertent impurities; and

wherein the stent being configured for insertion into a living body.

12. The stent of claim 11, wherein an abundance of a specific crystal orientation in a working direction of a worked portion for the ferrous alloy is at least 2.0.

13. The stent of claim 11, wherein the ferrous alloy includes from 38.8 to 46.4% by mass of iron.

14. The stent of claim 11, wherein the stent body includes a plurality of undulating bends provided in an axial direction.

15. The stent of claim 11, wherein the stent body is composed of braided wire.

16. The stent of claim 11, wherein the stent body has a wall thickness of 0.2 mm or less.

17. The stent of claim 16, wherein the stent body has a wall thickness of 0.10 mm or less.

18. The stent of claim 11, wherein the ferrous alloy comprises a composition which includes from 25 to 35% by mass of nickel, from 10 to 30% by mass of cobalt, from 2 to 8% by mass of aluminum, from 3 to 20% by mass of tantalum, and the balance being from 35 to 50% by mass of iron and inadvertent impurities.

19. The stent of claim 11, wherein the stent body includes a plurality of undulating rings united by partly shared linear segments configured to exhibit a uniform expansion retaining force, each said undulating ring including a plurality of first-side bends and a plurality of second-side bends, and said plurality of linear segments include a plurality of short linear segments and a plurality of long linear segments.