Expandable stent

• US 6,022,370 A
• Filed: 09/25/1997
• Issued: 02/08/2000
• Est. Priority Date: 10/01/1996
• Status: Expired due to Term

• Current Assignee: Numed LLC
• Original Assignee: Numed LLC
• Inventors: Tower, Allen J.
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): Bui, Vy Q.
• Application Number:
  US08/937,396
• Time in Patent Office: 866 Days
• Field of Search: 606/194, 606/191, 606/192, 606/195, 623/1
• US Class Current: 606/194
• 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 2002/30451 soldered or brazed or welded
• CPC Class Codes: A61F 2220/0058 soldered or brazed or welded
• CPC Class Codes: A61F 2310/00149 Platinum or Pt-based alloys
• CPC Class Codes: A61F 2310/00155 Gold or Au-based alloys
• CPC Class Codes: A61L 31/022 Metals or alloys
• CPC Class Codes: C22C 5/02 Alloys based on gold
• CPC Class Codes: C22C 5/04 Alloys based on a platinum group metal

Abstract

A radially expandable stent which is formed from a fine wire bent into a serpentine flat ribbon which is wound around a mandrel into a cylindrical sleeve for mounting on a balloon catheter for transluminal insertion in a vessel. The wire forming the stent comprises an alloy selected from the group consisting of Pt--Ir or Au--Ni, and where the alloy exhibits a tensile strength of about 155,000 to 175,000 PSI.

Claims

1. A radially expandable stent for intravascular implantation that includes

a plurality of helically aligned circumferential sections including two end sections and a plurality of intermediate sections that define a cylinder having a longitudinal axis, said cylinder formed of a continuous wire with said circumferential sections being spaced along said axis in abutting contact,

each of said circumferential sections having expandable segments that impart radial expandability to said sections whereby said sections have an unexpanded insertion circumference and an expanded implantation circumference that is greater than said insertion circumference,

said expandable segments being in their unexpanded mode, teardrop shaped elements that are alternately inverted about said circumferential sections, each element containing a base and a pair of legs that come together with a common apex when the stent is in a unexpanded condition,

said expandable segments being in their expanded mode, U-shaped elements that are alternately inverted about said circumferential sections,

one of said end sections having a free end that is passed back along the circumferential sections and is looped or wrapped around the circumferential sections at a plurality of preselected locations to provide dimensional stability and to prevent axial expansion of the stent during radial expansion.

2. The stent of claim 1 in which the wire forming the stent comprises an alloy selected from the group consisting of Pt--Ir or Au--Ni, and where the alloy exhibits a tensile strength of about 155,000 to 175,000 PSI.

3. The stent of claim 2 in which the alloy comprises about 90 wt % Pt and 10 wt % Ir.