Biodegradable polymeric stents

• US 9,554,925 B2
• Filed: 04/17/2014
• Issued: 01/31/2017
• Est. Priority Date: 05/30/2006
• Status: Active Grant

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Inventors: Gale, David C., Huang, Bin, Abbate, Anthony J., Limon, Timothy A., Kleine, Klaus
• Primary Examiner(s): Koehler, Christopher M
• Application Number:
  US14/255,896
• Publication Number:
  US 20140225312A1
• Time in Patent Office: 1,020 Days
• Field of Search: 295/08, 295/57, 295/58, 295/05, 295/15, 295/16, 294/46, 294/52, 623/1.15, 623/1.16, 219/121.6, 219/121.67, 219/121.69, 219/121.71, 219/121.72, 219/121.85
• US Class Current: 1/1
• 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 biodegradable stent comprising:

a cylindrically-shaped scaffold comprising a poly(L-lactide)-based biodegradable polymer,

wherein the scaffold includes a pattern of interconnecting struts, the scaffold being formed by cutting the pattern in a tube at a target diameter,

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 has induced molecular orientation in the circumferential direction which provides radial strength for supporting a blood vessel, the molecular orientation induced by heating and radially deforming the tube to the target diameter prior to forming the pattern,

wherein the heating and radially deforming increase crystallinity of the tube, the tube having a degree of crystallinity between 35% and 55% after the heating and radial deforming,

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

2. The stent of claim 1, wherein prior to heating and radially deforming the biodegradable polymer has a degree of crystallinity between 10% and 15%.

3. The stent of claim 1, wherein the biodegradable polymer is a copolymer.

4. The stent of claim 1, wherein the biodegradable polymer is a mixture of polymers.

5. The stent of claim 1, wherein a radial draw ratio of the radial deforming of the tube is between 2 and 6.

6. The stent of claim 1, wherein the stent is crimped on to a balloon at a diameter less than the target diameter so that the stent can be delivered into the blood vessel.