Elastomerically impregnated ePTFE to enhance stretch and recovery properties for vascular grafts and coverings

• US 20040024442A1
• Filed: 06/25/2002
• Published: 02/05/2004
• Est. Priority Date: 06/25/2002
• Status: Active Grant

• Current Assignee: Lifeshield Sciences LLC (Acacia Research Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Sowinski, Krzysztof, Rakos, Ronald
• Granted Patent: US 7,789,908 B2
• Time in Patent Office: Days
• US Class Current: 623/1.13
• 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 27/507 for artificial blood vessels apparatus for applying cells on a blood vessel prosthesis A61F2/062
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene
• CPC Class Codes: Y10T 428/249933 Fiber embedded in or on the surface of a natural or synthetic rubber matrix

Abstract

This invention relates to an elastomerically recoverable PTFE material that includes a longitudinally compressed fibrils of ePTFE material penetrated by elastomeric material within the pores defining the elastomeric matrix. The elastomeric matrix and the compressed fibrils cooperatively expand and recover without plastic deformation of the ePTFE material. This invention was used for various prosthesis, such as a vascular prosthesis like a patch, a graft and an implantable tubular stents. Furthermore, this invention discloses a method of producing the elastomerically recoverable PTFE material which include the steps of: providing the specified ePTFE, defined by the nodes and fibrils, to meet the desired end use; longitudinally compressing the fibrils of the ePTFE, the pore size sufficiently enough to permit penetration of the elastomeric material; applying the elastomeric material within the pores to provide a structurally integral elastomerically recoverable PTFE material defining an elastomeric matrix. The elastomeric material is applied to the ePTFE by dip, brush or spray coating techniques. The compression step and the application steps are interchangeable to produce the desired properties for the end use material. Finally, the elastomeric material is dried within the pores of the longitudinally compressed ePTFE to solidify the elastomeric matrix.

Claims

1. An elastomerically recoverable PTFE material comprising:

(a) an ePTFE material defined by nodes and fibrils, said fibrils being in longitudinally compressed state and defining pores of a size sufficient to permit penetration of an elastomeric material; and

(b) an elastomeric matrix within said pores;

said compressed fibrils and elastomeric matrix cooperatively permitting longitudinal expansion and elastomeric recovery without plastic deformation of said ePTFE material.

2. A vascular prosthesis comprising:

(a) an ePTFE material defined by nodes and fibrils, said fibrils being in longitudinally compressed state and defining pores of a size sufficient to permit penetration of an elastomeric material; and

(b) an elastomeric matrix within said pores;

said compressed fibrils and elastomeric matrix cooperatively permitting longitudinal expansion and elastomeric recovery without plastic deformation of said ePTFE material.

3. The vascular prosthesis of claim 2 wherein said vascular prosthesis is a patch.

4. The vascular prosthesis of claim 2 wherein the vascular prosthesis is a graft.

5. An implantable tubular stent graft comprising:

(a) an ePTFE material deformed by nodes and fibrils, said fibrils being in longitudinally compressed state and defining pores of a size sufficient to permit penetration of an elastomeric material;

(b) an elastomeric matrix within said pores;

said compressed fibrils and elastomeric matrix cooperatively permitting longitudinal expansion and elastomeric recovery without plastic deformation of said ePTFE material; and

(c) a longitudinally expandable stent.

6. A method of producing an elastomerically recoverable PTFE structure comprising the steps of:

(a) providing an ePTFE material defined by nodes, fibrils and pores, wherein said pore size is a space defined by the distance between said nodes and distance between said fibrils; and

(b) compressing said fibrils longitudinally wherein said pore size is sufficient to permit penetration of elastomeric material; and

(c) applying said elastomeric material within said pores to provide a structurally integral elastomerically recoverable PTFE material.

7. The method according to claim 6 further comprising the step of permitting the elastomeric material to dry within said pores while said fibrils are still longitudinally compressed defining the elastomeric matrix.

8. The method according to claim 6 wherein said ePTFE material is a tube, having an internal diameter and an external diameter.

9. The method according to claim 8 wherein said compressing step includes the steps of:

(a) pulling the ePTFE tube over a mandrel having an outer diameter of approximately the same dimensions as the internal diameter of the ePTFE tube; and

(b) compressing at least a portion of the ePTFE tube along the longitudinal axis of the tube while the tube is supported by the mandrel.

10. The method according to claim 6 wherein said applying step includes the step of dip coating at least the compressed portion of the ePTFE material into a container of elastomeric material.

11. The method according to claim 6 wherein said applying step includes the step of spray coating at least the compressed portion of the ePTFE material with the elastomeric material.

12. The method according to claim 6 wherein said applying step includes the step of brushing the elastomeric material onto at least the compressed portion of the ePTFE material.

13. The method according to claim 6 wherein said compressing step includes the step of compressing the ePTFE material uniformly along its entire length, and wherein said applying step includes the applying elastomeric material over the entire longitudinally compressed ePTFE material.

14. A method of producing an elastomerically recoverable PTFE structure comprising the steps of:

(a) providing an ePTFE material defined by nodes, fibrils and pores, wherein said pore size is a space defined by the distance between said nodes and distance between said fibrils; and

(b) applying said elastomeric material to said pores; and

(c) compressing said fibrils longitudinally wherein said pore size is sufficient to permit penetration of elastomeric material pores to provide a structurally integral elastomerically recoverable PTFE material.

15. The method according to claim 14 further comprising the step of permitting the elastomeric material to dry within said pores while said fibrils are still longitudinally compressed defining the elastomeric matrix.

16. The method according to claim 14 wherein said ePTFE material is a tube, having an internal diameter and an external diameter.

17. The method according to claim 14 wherein said compressing step includes the steps of:

(a) pulling the ePTFE tube over a mandrel having an outer diameter of approximately the same dimensions as the internal diameter of the ePTFE tube; and

(b) compressing at least a portion of the ePTFE tube along the longitudinal axis of the tube while the tube is supported by the mandrel.

18. The method according to claim 14 wherein said applying step includes the step of dip coating at least the compressed portion of the ePTFE material into a container of elastomeric material.

19. The method according to claim 14 wherein said applying step includes the step of spray coating at least the compressed portion of the ePTFE material with the elastomeric material.

20. The method according to claim 14 wherein said applying step includes the step of brushing the elastomeric material onto at least the compressed portion of the ePTFE material.

21. The method according to claim 14 wherein said applying step comprises the step of applying elastomeric material over the entire longitudinally compressed ePTFE material, and wherein the compressing step comprises the step of compressing the ePTFE material uniformly along its entire length.