Expandable stents and method for making same

• US 5,916,234 A
• Filed: 07/21/1997
• Issued: 06/29/1999
• Est. Priority Date: 12/28/1993
• Status: Expired due to Term

• Current Assignee: Advanced Cardiovascular Systems Incorporated
• Original Assignee: Advanced Cardiovascular Systems Incorporated
• Inventors: Lam, Sharon S.
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): Lewis, William W.
• Application Number:
  US08/896,731
• Time in Patent Office: 708 Days
• Field of Search: 600/1, 600/108, 600/191, 600/194, 600/195, 600/198, 600/200, 623/1, 623/12
• US Class Current: 606/198
• 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 2002/91508 the meander having a difference in amplitude along the band
• CPC Class Codes: A61F 2002/91516 the meander having a change in frequency along the band
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: B29C 55/30 Drawing through a die pultrusion B29C70/52
• CPC Class Codes: B29L 2031/7534 Cardiovascular protheses
• CPC Class Codes: B29L 2031/7736 Sinusoidal
• CPC Class Codes: Y10S 623/903 Blood vessel

Abstract

The invention is directed to an expandable stent for implantation in a body lumen, such as an artery. The stent consists of a plurality of radially expandable cylindrical elements generally aligned on a common longitudinal stent axis and interconnected by one or more interconnecting members placed so as to limit longitudinal contraction during radial expansion. The individual radially expandable cylindrical elements are formed in an irregular serpentine pattern designed to expand evenly under radial stress, and maximize the overall radial expansion ratio.

Claims

1. A method for implanting a stent in a body lumen, the method comprising:

providing a stent formed from a pseudoelastic or shape memory alloy, the stent having a first contracted condition and a second expanded condition, a plurality of adjacent cylindrical elements each having a circumference extending around a longitudinal stent axis, the cylindrical elements being arranged in alignment along the longitudinal stent axis, the cylindrical elements formed in a generally serpentine wave pattern transverse to the longitudinal axis and containing a plurality of alternating peaks and valleys, at least the peaks having varying radii of curvature;

the stent self-expanding from the first contracted condition to the second expanded condition; and

forming a plurality of projecting edges that project radially outwardly from the cylindrical elements as the stent self-expands from the first contracted condition to the second expanded condition.

2. The method of claim 1, wherein the pseudoelastic alloy includes NiTi.

3. The method of claim 2, wherein the self-expanding step includes expanding isothermally.

4. The method of claim 1, wherein the shape memory alloy includes NiTi.

5. The method of claim 4, wherein the self-expanding step results from a change in temperature of the stent NiTi shape memory alloy.