Manufacturing process for polymeric stents

• US 10,390,979 B2
• Filed: 12/15/2016
• Issued: 08/27/2019
• Est. Priority Date: 05/30/2006
• Status: Expired due to Fees

• Current Assignee: Advanced Cardiovascular Systems Incorporated
• Original Assignee: Advanced Cardiovascular Systems Incorporated
• Inventors: Gale, David C., Huang, Bin, Abbate, Anthony J., Limon, Timothy A., Kleine, Klaus
• Primary Examiner(s): Koehler, Christopher M
• Application Number:
  US15/379,665
• Publication Number:
  US 20170095359A1
• Time in Patent Office: 985 Days
• Field of Search: 29508, 29557, 29558, 29505, 29515, 29516, 29446, 29452, 623 115, 623 116, 2191216, 21912167, 21912169, 21912171, 21912172, 21912185
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• 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 2002/821 Ostial stents
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: B23K 2103/42 Plastics B23K2103/16 takes precedence
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 26/384 of specially shaped holes
• CPC Class Codes: B23K 26/402 involving non-metallic material, e.g. isolators
• CPC Class Codes: B29C 2793/0009 Cutting out
• CPC Class Codes: B29C 48/0022 combined with cutting
• CPC Class Codes: B29C 48/022 characterised by the choice of material
• CPC Class Codes: B29C 48/09 Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
• CPC Class Codes: B29C 55/00 Shaping by stretching, e.g. drawing through a die; Apparatus therefor B29C61/08 takes precedence
• CPC Class Codes: B29C 55/24 radial
• CPC Class Codes: B29C 65/02 by heating, with or without pressure
• CPC Class Codes: B29C 66/534 Joining single elements to open ends of tubular or hollow articles or to the ends of bars
• CPC Class Codes: B29C 71/0063 for changing crystallisation
• CPC Class Codes: B29K 2995/0039 Amorphous
• CPC Class Codes: B29K 2995/006 : Bio-degradable, e.g. bioabsorbable, bioresorbable or bioerodible
• CPC Class Codes: B29L 2031/7534 : Cardiovascular protheses
• CPC Class Codes: Y10T 29/49874 : Prestressing rod, filament or strand
• CPC Class Codes: Y10T 29/49908 : Joining by deforming
• CPC Class Codes: Y10T 29/49913 : by constricting outer annulus
• CPC Class Codes: Y10T 29/49925 : Inward deformation of aperture or hollow body wall
• CPC Class Codes: Y10T 29/49927 : Hollow body is axially joined cup or tube
• CPC Class Codes: Y10T 29/49995 : Shaping one-piece blank by removing material

Abstract

Methods and systems of fabricating a polymeric stent are disclosed herein.

Claims

1. A method of fabricating a stent comprising:

forming a polymer tube made of a biodegradable polymer,

wherein forming the polymer tube comprises forming an extruded polymer tube and quenching the extruded polymer tube from a first temperature, the first temperature being above a melting temperature of the biodegradable polymer, to a second temperature, the second temperature being below a glass transition temperature of the biodegradable polymer, such that the biodegradable polymer of the formed tube is an amorphous or substantially amorphous glassy polymer;

processing the tube to increase the crystallinity of the biodegradable polymer from amorphous or substantially amorphous to between 35% and 55%;

cutting a pattern in the processed tube to form a cylindrically-shaped scaffold, wherein the scaffold includes a pattern of interconnecting struts,

wherein the pattern comprises a plurality of cylindrical rings of struts and longitudinal linking struts connecting the rings,

wherein the rings include bending elements including struts that flex inward to allow crimping of the scaffold and flex outward to allow expansion of the scaffold,

wherein the scaffold is radially expandable in a blood vessel of a body and has adequate radial strength to hold open the blood vessel, and

wherein the stent comprises the scaffold.

2. The method of claim 1, wherein the biodegradable polymer is a copolymer.

3. The method of claim 1, wherein the biodegradable polymer is a mixture of polymers.

4. The method of claim 1, wherein the processing comprises radial expansion of the tube to a target diameter at a third temperature, the third temperature being above the glass transition temperature (Tg) of the biodegradable polymer.

5. The method of claim 4, wherein a radial draw ratio of the radial expansion of the tube is between 2 and 6.

6. The method of claim 1, further comprising crimping the stent on to a balloon at a diameter less than a target diameter so that the stent can be delivered into the blood vessel.

7. The method of claim 1, wherein the processing comprises increasing a temperature of the tube above the glass transition temperature (Tg) of the biodegradable polymer.