Flexible stent and method of manufacture

• US 6,998,060 B2
• Filed: 03/02/2001
• Issued: 02/14/2006
• 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: Tomonto, Charles V.
• Primary Examiner(s): Olsen, Allan
• Application Number:
  US09/797,815
• Publication Number:
  US 20020121497A1
• Time in Patent Office: 1,810 Days
• Field of Search: 216/8, 216/49, 216/75, 216/100
• US Class Current: 216/8
• 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 2002/91583 by a bridge, whereby at least one of its ends is connected along the length of a strut between two consecutive apices within a band

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 method for manufacture by controlled variable etching, of a stent with struts having varying strut thicknesses, said stent having a generally tubular configuration with a longitudinal axis and a generally thin wall containing said struts therein, said method comprising:

creating a plurality of photoresist images of varying size on the surface of a preformed stent, said photoresist images placed on said stent according to varying configurations;

etching a pattern of struts on said stent around said plurality of photoresist images on the surface of said stent, said photoresist images placed on said stent according to said varying configurations, such that said resultant stent containing said etched pattern has different strut thicknesses along the stent longitudinal axis.

2. The method of making a stent as described in claim 1, further comprising the stent having a plurality of struts, and said stent formed with a plurality of struts tapered in radial thickness.

3. The method of making a stent as described in claim 1, further comprising the stent having a plurality of struts, and said stent formed with a plurality of struts variable in radial thickness.

4. The method of making a stent as described in claim 1, further comprising the stent having a plurality of struts, and said stent formed with a plurality of struts contoured along their length.

5. The method of making a stent as described in claim 1, further comprising the stent having a plurality of struts, and said stent formed with a plurality of struts non-rectangular in cross-section.