Rotational spun material covered medical appliances and methods of manufacture

• US 10,675,850 B2
• Filed: 08/21/2015
• Issued: 06/09/2020
• Est. Priority Date: 01/16/2012
• Status: Active Grant

• Current Assignee: Merit Medical Systems, Inc.
• Original Assignee: Merit Medical Systems, Inc.
• Inventors: Hall, John William, Eller, Zeke, Kellar, Robert S., Oberg, Rachel Lynn, Dolmatch, Bart, Mower, Wayne, Radford, Robert J.
• Primary Examiner(s): Schall, Matthew W
• Application Number:
  US14/832,422
• Publication Number:
  US 20150352826A1
• Time in Patent Office: 1,754 Days
• CPC Class Codes: A61F 2/0077 Special surfaces of prostheses, e.g. for improving ingrowth A61F2/30767 takes precedence
• 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 2/852 Two or more distinct overlapping stents
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2/89 the wire-like elements comprising two or more adjacent rings flexibly connected by separate members
• CPC Class Codes: A61F 2002/065 Y-shaped blood vessels
• 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 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: A61F 2230/005 Rosette-shaped, e.g. star-shaped
• CPC Class Codes: A61L 2420/02 Methods for coating medical devices
• CPC Class Codes: A61L 2420/08 Coatings comprising two or more layers
• CPC Class Codes: A61L 27/34 Macromolecular materials
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61L 31/146 Porous materials, e.g. foams or sponges
• CPC Class Codes: B05D 1/005 Spin coating
• CPC Class Codes: B32B 2255/10 on synthetic resin layer or on natural or synthetic rubber layer
• CPC Class Codes: B32B 38/0036 : Heat treatment for heating or cooling of layers during lamination B32B37/06, B32B37/08
• CPC Class Codes: C08L 27/18 : Homopolymers or copolymers or tetrafluoroethene
• CPC Class Codes: C09D 127/18 : Homopolymers or copolymers of tetrafluoroethene
• CPC Class Codes: D01D 5/18 : by means of rotating spinnerets
• CPC Class Codes: D01F 6/12 : from polymers of fluorinated hydrocarbons

Abstract

A medical appliance or prosthesis may comprise one or more layers of rotational spun nanofibers, including rotational spun polymers. The rotational spun material may comprise layers including layers of polytetrafluoroethylene (PTFE). Rotational spun nanofiber mats of certain porosities may permit tissue ingrowth into or attachment to the prosthesis. Additionally, one or more cuffs may be configured to allow tissue ingrowth to anchor the prosthesis.

Claims

1. A method of constructing a medical appliance, the method comprising:

rotational spinning a first tube of polytetrafluoroethylene (PTFE) onto a mandrel, wherein the PTFE is expelled from a plurality of orifices of a spinneret under centrifugal force and hydrostatic force, wherein the spinneret rotates about an axis of rotation and the plurality of orifices are radially offset from the axis of rotation; and

sintering the first tube.

2. The method of claim 1, wherein the first tube of PTFE is rotational spun onto a rotating mandrel.

3. The method of claim 2, wherein the mandrel is positioned substantially orthogonal to an axis of rotation of a rotational spinning spinneret.

4. The method of claim 1, further comprising applying a second tube of rotational spun PTFE around the first layer.

5. The method of claim 4, further comprising:

applying a scaffolding structure around the first tube and

applying a fluorinated ethylene propylene (FEP) layer around the first tube and the scaffolding structure, prior to applying the second tube of rotational spun PTFE.

6. The method of claim 5, further comprising heating the medical appliance such that the FEP layer bonds to the first and second tubes such that the FEP partially bonds to the fibers of the first and second tubes.

7. The method of claim 6, wherein the FEP flows into and coats the fibers of the first and second tubes while maintaining the porosity of the tubes.

8. The method of claim 4, wherein the second tube of rotational spun PTFE is formed by a method comprising:

rotational spinning the second tube of PTFE onto a rotating mandrel; and

sintering the second tube.

9. The method of claim 6, further comprising applying a compressive wrap around the second tube before the medical appliance is heat treated.

10. The method of claim 1, wherein rotational spinning the first tube of PTFE comprises:

mixing a PTFE dispersion with polyethylene oxide (PEO), wherein the PEO is dissolved in water to form a mixture; and

discharging the mixture from an orifice onto the rotating mandrel.

11. The method of claim 1, wherein the mandrel comprises a main portion and two leg portions, the main portion configured to coincide with a main lumen of a bifurcated medical appliance and the two leg portions configured to coincide with leg portions of bifurcated medical appliance.

12. The method of claim 11, wherein the two leg portions of the mandrel are removable from the main portion of the mandrel.

13. The method of claim 11, wherein the first tube is rotational spun by rotating the mandrel about an axis of the leg portions of the mandrel while rotationally spinning fibers and rotating the mandrel about an axis of the main portion of the mandrel while rotationally spinning fibers.