Prosthesis with in-wall modulation

• US 6,042,666 A
• Filed: 06/26/1998
• Issued: 03/28/2000
• Est. Priority Date: 12/03/1996
• Status: Expired due to Term

• Current Assignee: Atrium Medical Corporation (Getinge AB)
• Original Assignee: Atrium Medical Corporation (Getinge AB)
• Inventors: Swanick, Tom, Gingras, Peter, Martakos, Paul, Karwoski, Theodore, Herweck, Steve A.
• Primary Examiner(s): Lorin, Francis J.
• Application Number:
  US09/105,736
• Time in Patent Office: 641 Days
• Field of Search: 156/60, 156/50, 156/47
• US Class Current: 156/47
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/105 Skin implants, e.g. artificial skin
• CPC Class Codes: A61F 2/2412 with soft flexible valve members, e.g. tissue valves shaped like natural valves check valves with flexible valve members in general F16K15/14
• 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 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: A61L 27/16 obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/34 Macromolecular materials
• CPC Class Codes: A61L 27/40 Composite materials, i.e. containing one material dispersed in a matrix of the same or different material
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene

Abstract

The wall of a prosthesis has a region which modulates communication through the porosity of the wall. The prosthesis is unitary, but may be assembled in successive bodies which are coalesced, so that the porous microstructure changes distinctly at stages through the thickness dimension of the wall. One embodiment is formed entirely of fluoropolymer, and has at least one surface adapted to support tissue regeneration and ingrowth. The modulation region is a stratum of high water entry pressure that reduces pulsatile hydraulic pressure transmission, or locally alters fluid-born-distribution of biological material through the wall and allows more natural gradients for tissue regeneration and growth in the outer region of the wall.

Claims

1. A method of making a device, such method comprising the steps of

placing at least first and second porous PTFE portions one over the other with a low porosity PTFE portion therebetween to form an adhesive-free assemblage, and

heating the assemblage to coalesce the assemblage into a unitized device.

2. The method of claim 1, wherein the device is a prosthesis and said first and second portions are tubes.

3. The method of claim 2, wherein said substantially non-porous PTFE portion is a PTFE tube, and the step of placing to form an assemblage includes the steps of placing said tubes on a mandrel, and wherein the step of heating includes heating the assemblage while it is on the mandrel so that force of shrinkage of the tubes against the mandrel when heated joins the tubes together without solvent.

4. The method of claim 1, wherein the low porosity PTFE portion has a bias orientation and a thickness below approximately one millimeter.

5. A method of forming a device, such method comprising the steps of

providing a first portion of porous PTFE,

providing a second portion of low or non-porous material surrounding said first portion,

providing a third portion of porous PTFE surrounding said second portion, and

coalescing said first portion, said second portion and said third portion into a single wall wherein said second portion modulates cell growth in portions of said wall formed by said first and third PTFE portions and limits through penetration of cell growth.

6. A method of making a prosthetic device, the method comprising the steps of

providing first and third tubes having a cellularly penetrable structure,

providing a second permeable tube between said first and third portion having a structure effective to limit cell growth between said first and third portions, and

coalescing said first tube, said second tube, and said third tube into a unitary prosthesis.

7. The method of claim 6, wherein the step of providing said first and third tubes includes the step of forming said first tube from a fluoropolymer material.

8. The method of claim 6, wherein the step of providing said second permeable tube includes the step of forming said second tube from a fluoropolymer material.

9. The method of claim 6, wherein the step of coalescing includes the step of applying heat to said first, second, and third tubes.

10. The method of claim 9, wherein said step of coalescing further includes the step of applying a radial compressive force to said third tube.

11. The method of claim 6, further including the step of radially expanding said third tube prior to the step of providing said second tube between said first and third tubes.

12. A method of making a prosthetic device, the method comprising the steps of

providing a first fluoropolymer tube,

providing a permeable fluoropolymer material having a permeability effective for modulating hydrostatic pressure,

wrapping said fluoropolymer material over the outer surface of the first tube,

placing a second fluoropolymer tube over said fluoropolymer material and said first tube, and

coalescing said first and second tubes and said fluoropolymer material to form a unitary prosthesis.

13. The method of claim 12, wherein the step of coalescing includes the step of applying heat to said first and second tubes and said fluoropolymer material.

14. The method of claim 13, wherein said step of coalescing further includes the step of applying a radial compressive force to said second tube.

15. The method of claim 12, further including the step of radially expanding said second tube prior to the step of placing said second tube over said fluoropolymer material and said first tube.

16. The method of claim 12, wherein the step of wrapping includes the step of wrapping said fluoropolymer material in spiral winding over the outer surface of said first tube.

17. A prosthetic member comprising

a prosthesis wall having first, second, and third coaxial, permeable portions,

said first and third portions having a cellularly penetrable structure, and

said second portion positioned between said first and third portions and having a permeability less than said first portion to modulate cellular penetration of said first and third portions.

18. The prosthetic member of claim 17, wherein said second portion has a porosity less than said first portion.

19. The prosthetic member of claim 17, wherein said first and third portions are continuous tubes and said second portion is a biased wrap.

20. The prosthetic member of claim 17, wherein said first and third portions are continuous tubes and said second portion is a non-biased wrap.

21. The prosthetic member of claim 17, wherein said second portion is permeable to plasma solutes.

22. The prosthetic member of claim 17, wherein said first, second, and third portions are formed of a fluoropolymer.

23. The prosthetic member of claim 17, wherein said first, second, and third portions are coalesced together to form said prosthesis wall.

24. The prosthetic member of claim 17, wherein said second portion has a water entry pressure greater than said first portion.

25. The prosthetic member of claim 17, wherein said second portion has a permeability effective for modulating hydrostatic pressure.

26. The prosthetic member of claim 17, wherein said second portion has a permeability effective to allow passage of gas and fluid at a controlled rate between said first and third portions.

27. A prosthetic member comprising

a prosthesis wall having first, second, and third coaxial, permeable portions,

said first and third portions having a cellularly penetrable structure, and

said second portion positioned between said first and third portions and having a structure effective to limit cell growth between said first and third portions.

28. The prosthetic member of claim 27, wherein said second portion is permeable to plasma solutes.