Flexible stent

• US 6,942,689 B2
• Filed: 03/02/2001
• Issued: 09/13/2005
• Est. Priority Date: 03/01/2001
• Status: Expired due to Term

• Current Assignee: Cardinal Health Switzerland 515 GmbH (Cardinal Health, Inc.)
• Original Assignee: Cordis Corporation (Cardinal Health, Inc.)
• Inventors: Majercak, David C.
• Primary Examiner(s): McDermott, Corrine
• Assistant Examiner(s): Stewart, Alvin
• Application Number:
  US09/797,816
• Publication Number:
  US 20020123797A1
• Time in Patent Office: 1,656 Days
• Field of Search: 623/1.1, 623/1.12, 623/1.15, 623/1.17, 623/1.16, 623/1.18, 623/1.19, 623/1.2, 623/1.21, 606/192, 606/194
• 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 2002/91508 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 2002/91525 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 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/91566 connected trough to trough
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2230/0054 V-shaped

Abstract

A preferred embodiment of a stent provides a folded strut section that provides both structural rigidity and reduction in foreshortening of the stent mechanism. A flexible section provides flexibility for delivery of the stent mechanism. In a second embodiment, flexible section columns are angled with respect to each other, and to the longitudinal axis of the stent. These relatively flexible sections are oppositely phased in order to negate any torsion along their length. In yet another embodiment, the flexible connector can take on an undulating shape (like an “N”), but such that the longitudinal axis of the connector is not parallel with the longitudinal axis of the stent. Finally, a new method is disclosed for making stents. The method consists of performing a standard photochemical machining process of cutting, cleaning and coating the tube with a photoresist. However, unlike former methods, the photoresist image is developed on the surface of the cylindrical metallic tube, which results in a controlled variable etching rate at selected sites on the cylindrical metallic tube during the etching process. Further embodiments provide living hinge connectors and connections along the length of the radial strut member.

Claims

1. A stent having a generally tubular configuration and a longitudinal axis, comprising:

a plurality of radial strength portions and a plurality of flexible portions, each of said radial strength portions comprising a plurality of radial struts connected one to the other and each said flexible portion comprising a plurality of flexible struts, and each of the flexible struts connected to a radial strut by a living hinge having an inner arc and an outer arc, such that said outer arc does not shorten in the longitudinal direction upon expansion of the stent from an unexpanded configuration.

2. The stent of claim 1 wherein each flexible portion comprises a series of flexible struts placed around the circumference of the stent.

3. The stent of claim 2 wherein the series of flexible struts of adjacent flexible portions are circumferentially offset around the circumference of the stent.

4. The stent of claim 1 wherein a radial strut in a ring of radial struts is placed about 90°

out of phase with the most adjacent radial strut in an adjacent ring of radial struts.

5. The stent of claim 2 wherein a radial strut in a ring of radial struts is placed about 90°

out of phase with the most adjacent radial strut in an adjacent ring of radial struts.