Stent for use following balloon angioplasty

• US 4,795,458 A
• Filed: 07/02/1987
• Issued: 01/03/1989
• Est. Priority Date: 07/02/1987
• Status: Expired due to Term

• Current Assignee: Barrie F. Regan
• Original Assignee: Barrie F. Regan
• Inventors: Regan, Barrie F.
• Primary Examiner(s): Apley, Richard J.
• Assistant Examiner(s): Cannon, Alan W.
• Application Number:
  US07/069,364
• Time in Patent Office: 551 Days
• Field of Search: 623/1, 623/12, 623/66, 128/341, 128/343, 128/745, 128/324 R, 128/DIG. 22, 128/303 R, 604/272, 604/273, 604/274, 427/2
• US Class Current: 623/1.19
• CPC Class Codes: A61F 2/0004 Closure means for urethra or rectum, i.e. anti-incontinence devices or support slings against pelvic prolapse
• 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 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61L 2400/16 Materials with shape-memory or superelastic properties
• CPC Class Codes: A61L 31/088 Other specific inorganic materials not covered by A61L31/084 or A61L31/086

Abstract

A stent for implanting in a blood vessel following balloon angioplasty to prevent restenosis. The stent is a helical coil of a shape memory alloy tape or wire. The coil has a diameter less than that of the blood vessel in which it is to be implanted. The tape or wire has previously been wound to form a helical coil having a diameter equal to or slightly greater than the inside diameter of said blood vessel, this coil is than heated to an elevated temperature for a time sufficient to fix the shape of the second mentioned coil in the memory of the tape or wire, cooled to ambient temperature and then rewound to form the first mentioned helical coil.

Claims

1. A stent for implanting in a blood vessel following balloon angioplasty to prevent restonosis, said stent consisting of a helical coil of marmem alloy tape or wire having a diameter less than that of the blood vessel in which it is to be implanted, said tape or wire having earlier been wound to form a helical coil having a diameter equal to or greater than the inside diameter of said blood vessel and heated to an elevated temperature for a time to fix the shape of the second mentioned helical coil in the memory of the alloy and then covered with a thin surface coating of tin.

2. The stent defined in claim 1 where in the marmem alloy is a nitinol.

3. The stent defined in claim 1 wherein the tin surface coating contains from about 1% to 10% by weight of indium.

4. A stent for insertion into a blood vessel following balloon angioplasty to prevent restenosis which comprises:

a helical coil having a diameter slightly less than the diameter of the blood vessel in to which it is to be inserted,

said coil being formed of a corrosion resistant shape memory alloy having a transition temperature in the range about 39°

-60°

C. which has been wound into a helical coil having a diameter equal to or slightly greater than that of the said blood vessel, heated to an elevated temperature for a time sufficient to fix the larger diameter coil shape in the memory of said alloy, then coated with a thin surface coating of tin and then rewound to form the first mentioned helical coil.

5. The stent defined in claim 4 wherein the shape memory alloy is a nitinol.