Elastomerically impregnated ePTFE to enhance stretch and recovery properties for vascular grafts and coverings
An elastomerically recoverable PTFE material is provided including a longitudinally compressed fibrils of ePTFE material penetrated by elastomeric material within the pores defining the elastomeric matrix. The elastomeric matrix and the compressed fibris cooperatively expand and recover without plastic deformation of the ePTFE material. The material may be used for various prosthesis, such as a vascular a prosthesis like a patch, a graft and an implantable tubular stent. Further, a method of producing the elastomerically recoverable PTFE material is provided herein.
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, wherein said elastomeric matrix is a polycarbonate urethane material having a shore hardness rating between 70A and 75 D.
2 . A vascular prosthesis of claim 1 wherein said elastomeric recovery of PTFE matrix is a vascular prosthesis.
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 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;
(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, wherein said elastomeric matrix is a polycarbonate urethane material having a shore hardness rating between 70A and 75 D; 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;
(b) providing an elastomeric material, said elastomeric matrial is a polycarbonate urethane material having a shore hardness rating between 70A and 75 D;
(c) compressing said fibrils longitudinally wherein said pore size is sufficient to permit penetration of said elastomeric material; and
(d) 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 - 21 . (canceled)