Radially expandable polytetrafluoroethylene

• US 7,465,483 B2
• Filed: 02/05/2004
• Issued: 12/16/2008
• Est. Priority Date: 06/27/1994
• Status: Expired due to Fees

• Current Assignee: Bard Peripheral Vascular Incorporated (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Colone, William M.
• Primary Examiner(s): Dye; Rena L
• Assistant Examiner(s): AUGHENBAUGH, WALTER
• Application Number:
  US10/772,703
• Publication Number:
  US 20040157024A1
• Time in Patent Office: 1,776 Days
• Field of Search: 428/341.1, 428/34.9, 428/35.2, 428/35.7, 428/36.5, 428/36.9, 604/27, 604/93.01, 606/108, 606/191, 623/1.1, 623/1.49, 623/1.54
• US Class Current: 428/36.9
• CPC Class Codes: A61F 2/07 Stent-grafts
• 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 2002/072 Encapsulated stents, e.g. wire or whole stent embedded in lining
• CPC Class Codes: A61F 2002/075 the stent being loosely attached to the graft material, e.g. by stitching
• CPC Class Codes: A61F 2210/0019 operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61F 2220/0058 soldered or brazed or welded
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61L 31/048 obtained by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: B29C 2791/001 Shaping in several steps
• CPC Class Codes: B29C 48/00 Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor extrusion blow-moulding B29C49/04
• CPC Class Codes: B29C 48/0012 combined with shaping by internal pressure generated in the material, e.g. foaming
• CPC Class Codes: B29C 48/0018 combined with shaping by orienting, stretching or shrinking, e.g. film blowing B29C48/0017 takes precedence
• 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 49/04 Extrusion blow-moulding
• CPC Class Codes: B29C 49/6472 in several stages
• CPC Class Codes: B29C 55/005 characterised by the choice of materials
• CPC Class Codes: B29C 55/24 radial
• CPC Class Codes: B29C 55/26 biaxial
• CPC Class Codes: B29C 67/04 : Sintering combined with compression B29C43/00
• CPC Class Codes: B29K 2027/18 : PTFE, i.e. polytetrafluorethene , e.g. ePTFE, i.e. expanded polytetrafluorethene
• CPC Class Codes: B29K 2105/04 : cellular or porous
• CPC Class Codes: B29L 2023/005 : Hoses, i.e. flexible
• CPC Class Codes: B29L 2031/753 : Medical equipment; Accessories therefor bloodbags, medical bags B29L2031/7148; artificial eyes B29L2011/0008
• CPC Class Codes: B29L 2031/7542 : Catheters
• CPC Class Codes: C08L 27/18 : Homopolymers or copolymers or tetrafluoroethene
• CPC Class Codes: Y10S 623/901 : Method of manufacturing prosthetic device
• CPC Class Codes: Y10T 428/13 : Hollow or container type article [e.g., tube, vase, etc.]
• CPC Class Codes: Y10T 428/1328 : Shrinkable or shrunk [e.g., due to heat, solvent, volatile agent, restraint removal, etc.]
• CPC Class Codes: Y10T 428/1334 : Nonself-supporting tubular film or bag [e.g., pouch, envelope, packet, etc.]
• CPC Class Codes: Y10T 428/1352 : Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/1376 : Foam or porous material containing
• CPC Class Codes: Y10T 428/139 : Open-ended, self-supporting conduit, cylinder, or tube-type article

Abstract

Extruded, stretched, sintered tubular PTFE materials are produced which are suited for use in the medical field as liners and covers for expandable stents. The PTFE materials have an unusually low REC (Radial Expansion Coefficient) and RER (Radial Expansion Ratio).

Claims

1. A radially expandable tube consisting of extruded expanded polytetrafluoroethylene having a microstructure of nodes interconnected by fibrils and having an original inner diameter, wherein said tube is pre-dilated and is then sintered to contract said tube to the original inner diameter, said tube exhibiting a radial expansion ratio of 1.0, wherein the radial expansion ratio is defined as the radial expansion coefficient divided by the radial expansion limit, wherein the radial expansion coefficient is defined as the maximum inflation pressure of the tube divided by the percent radial dilation of the tube at the maximum inflation pressure, and wherein the radial expansion limit is defined as the burst inflation pressure of the tube divided by the percent radial dilation of the tube at the burst inflation pressure.

2. The radially expandable tube according to claim 1, wherein said tube is attached to an expandable stent.

3. A porous polytetrafluoroethylene (PTFE) product comprising a pre-dilated tube that is sintered to form a contracted tube with a radial expansion ratio of about 1.0.

4. The PTFE product according to claim 3, wherein the tube is attached to an expandable stent.