Vascular grafts with multiple channels and methods for making

• US 9,198,749 B2
• Filed: 10/12/2007
• Issued: 12/01/2015
• Est. Priority Date: 10/12/2006
• Status: Active Grant

• Current Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Pathak, Chandrashekhar P.
• Primary Examiner(s): Hartley, Michael G
• Assistant Examiner(s): YOUNG, MICAH PAUL
• Application Number:
  US12/444,568
• Publication Number:
  US 20100057196A1
• Time in Patent Office: 2,972 Days
• Field of Search: 424422-426, 604/264, 604/265, 604/267
• US Class Current: 1/1
• CPC Class Codes: A61F 2/06 Blood vessels
• 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 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2250/0068 the pharmaceutical product being in a reservoir
• 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 48/001 Combinations of extrusion moulding with other shaping operations
• CPC Class Codes: B29C 48/23 with means for avoiding adhesion of the layers, e.g. for forming peelable layers
• CPC Class Codes: B29C 67/202 comprising elimination of a solid or a liquid ingredient
• CPC Class Codes: B29K 2027/18 PTFE, i.e. polytetrafluorethene , e.g. ePTFE, i.e. expanded polytetrafluorethene
• CPC Class Codes: B29K 2105/041 Microporous
• 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

Abstract

A wall, for example the wall of a vascular graft, has multiple channels within it. The channels may be used to hold drugs or reinforcing fibers. The channels may have a predetermined roughness. The channels may be formed by coextrusion using a soluble material, for example, to define the channels and then dissolving them to open the channels in the extrudate.

Claims

1. A method of forming a medical device, comprising:

co-extruding a first material and a second material into a cylinder of the first and second materials, such that, after extrusion, the second material defines at least one elongate structure extending generally along a length of the medical device surrounded by the matrix of the first material; and

prior to implantation of the medical device within a patient

removing the second material from the first material to leave a void in the first material;

twisting the cylinder such that the voids left in the first material, after removal of the second material, are formed into helices;

inserting a reinforcement filament into the voids left in the first material; and

forming the medical device into a vascular graft.

2. The method of claim 1 wherein the second material is granular with a particle size of not more than 100 μ

m.

3. The method of claim 1 wherein the second material is a soluble material and the removing includes dissolving the soluble material.

4. The method of claim 1 further comprising expanding the first material after removing the second material.

5. The method of claim 1 wherein the first material includes polytetrafluoroethylene.

6. The method of claim 1 further comprising filling the voids left in the first material, after removal of the second material, with a drug.

7. The method of claim 1 further comprising filling the voids left in the first material, after removal of the second material, with an antithrombogenic drug.

8. The method of claim 1 further comprising filling the voids left in the first material, after removal of the second material, with a drug/polymer mixture.