Claims
- 1. An endoluminal prosthesis, comprising:
an endoluminal stent made of a shape memory material, the endoluminal stent having an at least substantially austenite dimensional state whereby the endoluminal stent assumes a generally tubular conformation defining a central longitudinal lumen delimited by walls of the endoluminal stent, the walls having luminal and abluminal surfaces thereof; and a monolithic expanded polytetrafluoroethylene layer forming a continuous circumferential covering over at least a portion of the longitudinal axis of each of the luminal and abluminal surfaces of the endoluminal stent walls circumferentially enclosing at least a portion of the central longitudinal lumen of the endoluminal stent, the expanded polytetrafluoroethylene layer having a node and fibril microstructure wherein the fibrils have a generally uniaxial orientation throughout the monolithic expanded polytetrafluoroethylene layer.
- 2. The endoluminal prosthesis according to claim 1, wherein the shape memory stent further comprises a nickel-titanium alloy.
- 3. The endoluminal prosthesis according to claim 2, wherein the nickel-titanium alloy further comprises an alloy consisting essentially of nickel present at about 50 at. %, titanium present at about 50 at. %.
- 4. The endoluminal prosthesis according to claim 1, wherein the monolithic expanded polytetrafluoroethylene layer further comprises a luminal and an abluminal layer of expanded polytetrafluoroethylene tubular material intimately joined to one another through the walls of the endoluminal stent.
- 5. The endoluminal prosthesis according to claim 1, wherein the monolithic expanded polytetrafluoroethylene layer encapsulates the endoluminal stent in a reduced diametric dimension suitable for endoluminal delivery.
- 6. The endoluminal prosthesis according to claim 4, wherein the luminal and an abluminal layers of expanded polytetrafluoroethylene tubular material further comprise radially pre-expanded microporous polytetrafluoroethylene tubular members and the endoluminal stent made of a shape memory material is substantially encapsulated at an enlarged diametric dimension.
- 7. The endoluminal prosthesis according to claim 4, wherein the luminal and abluminal layers of expanded polytetrafluoroethylene material further comprise expanded polytetrafluoroethylene tubular members extruded at a diametric dimension sufficient to substantially encapsulate the endoluminal stent at its austenite dimensional state.
- 8. The endoluminal prosthesis according to any of claims 1 to 7, wherein the shape memory material comprising the endoluminal stent further comprises a pseudoelastic shape memory alloy.
- 9. An endoluminal prosthesis, comprising:
an endoluminal stent made of a material having an elastic spring tension having a generally tubular conformation defining a central longitudinal lumen delimited by walls of the endoluminal stent, the walls having luminal and abluminal surfaces thereof, the endoluminal stent having a first dimensional state whereby the endoluminal stent is radially constrained for endoluminal delivery into a body and a second dimensional state whereby the elastic spring tension is released and the endoluminal stent elastically deforms into contact with endoluminal tissue; and a monolithic expanded polytetrafluoroethylene layer forming a continuous circumferential covering over each of the luminal and abluminal surfaces of the endoluminal stent walls circumferentially enclosing at least a portion of the central longitudinal lumen of the endoluminal stent.
- 10. The endoluminal prosthesis according to claim 9, wherein the monolithic expanded polytetrafluoroethylene layer further comprises a luminal and an abluminal layer of expanded polytetrafluoroethylene tubular material intimately joined to one another through the walls of the endoluminal stent.
- 11. The endoluminal prosthesis according to claim 10, wherein the luminal and an abluminal layers of expanded polytetrafluoroethylene tubular material further comprise radially pre-expanded microporous polytetrafluoroethylene tubular members.
- 12. The endoluminal prosthesis according to claim 10, wherein the luminal and abluminal layers of expanded polytetrafluoroethylene tubular material further comprise polytetrafluoroethylene tubular members extruded at a diametric dimension sufficient to substantially encapsulate the endoluminal stent at an enlarged diametric dimension.
- 13. The endoluminal prosthesis according to claim 12, wherein the abluminal polytetrafluoroethylene tubular member is extruded at a diametric dimension greater than that required to encapsulate the abluminal wall of the endoluminal stent.
- 14. The endoluminal prosthesis according to claim 10, wherein the luminal and an abluminal layers of expanded polytetrafluoroethylene tubular material further comprise microporous polytetrafluoroethylene tubular members radially expandable under the influence of a radially outwardly directed pressure less than about six atmospheres.
- 15. The endoluminal prosthesis according to claim 10, wherein the luminal and an abluminal layers of expanded polytetrafluoroethylene tubular material further comprise microporous polytetrafluoroethylene tubular members radially expandable under the influence of a radially outwardly directed pressure less than about five atmospheres.
- 16. The endoluminal prosthesis according to claim 10, wherein the luminal and abluminal layers of expanded polytetrafluoroethylene material further comprise microporous polytetrafluoroethylene tubular members radially expandable under the influence of a radially outwardly directed pressure less than about four atmospheres.
- 17. The endoluminal prosthesis according to claim 10, wherein the luminal and abluminal layers of expanded polytetrafluoroethylene material further comprise radially expandable microporous polytetrafluoroethylene tubular members and the endoluminal prosthesis is radially expandable in vivo under the influence of a radially outwardly directed pressure applied from the central longitudinal lumen of the endoluminal prosthesis less than about six atmospheres.
- 18. The endoluminal prosthesis according to claim 10, wherein the luminal and abluminal layers of expanded polytetrafluoroethylene material further comprise radially expandable microporous polytetrafluoroethylene tubular members and the endoluminal prosthesis is radially expandable in vivo under the influence of a radially outwardly directed pressure applied from the central longitudinal lumen of the endoluminal prosthesis less than about five atmospheres.
- 19. The endoluminal prosthesis according to claim 10, wherein the luminal and abluminal layers of expanded polytetrafluoroethylene material further comprise radially expandable microporous polytetrafluoroethylene tubular members and the endoluminal prosthesis is radially expandable in vivo under the influence of a radially outwardly directed pressure applied from the central longitudinal lumen of the endoluminal prosthesis less than about 4.5 atmospheres.
- 20. The endoluminal prosthesis according to claim 10, wherein the luminal and abluminal layers of expanded polytetrafluoroethylene further comprise radially expandable microporous polytetrafluoroethylene tubular members and the endoluminal prosthesis is radially expandable in vivo under the influence of a radially outwardly directed pressure applied from the central longitudinal lumen of the endoluminal prosthesis less than about 3.0 atmospheres.
- 21. A method for making an encapsulated stent-graft, comprising the steps of:
a. concentrically engaging an endoluminal stent in a first diametric dimension about a first tubular expanded polytetrafluoroethylene member having a node and fibril microstructure in which the fibrils are oriented substantially parallel to the longitudinal axis of the tubular expanded polytetrafluoroethylene member; b. concentrically engaging a second tubular expanded polytetrafluoroethylene member having a node and fibril microstructure in which the fibrils are oriented substantially parallel to the longitudinal axis of the second tubular expanded polytetrafluoroethylene member, about the endoluminal stent and the first tubular expanded polytetrafluoroethylene member; c. applying a circumferential pressure about the first and second tubular expanded polytetrafluoroethylene members and the endoluminal stent interdisposed there between; and d. exposing the first and second tubular expanded polytetrafluoroethylene members and the endoluminal stent interdisposed there between stent in its enlarged diametric state to a temperature above the crystalline melt point of polytetrafluoroethylene for a period of time sufficient to monolithically join the layers of polytetrafluoroethylene to one another through the endoluminal stent forming a single substantially homogeneous layer of expanded polytetrafluoroethylene.
- 22. The method of claim 21, where the step (a) further comprises the steps of:
a. providing an endoluminal stent made of a shape memory material having a pre-defined austenite tubular dimensional state and cooling the endoluminal stent to a temperature below the martensite transformation temperature of the shape memory alloy; and b. deforming the endoluminal stent at a temperature below the martensite transformation temperature to a reduced diametric dimension suitable for endoluminal delivery thereof for engagement upon the first tubular polytetrafluoroethylene member.
- 23. The method of claim 21, wherein the step (a) further comprises the steps of:
a. providing a self-expanding endoluminal stent made of a material having an inherent spring tension; and b. deforming the endoluminal stent to a reduced diametric dimension suitable for endoluminal delivery thereof for engagement upon the first tubular polytetrafluoroethylene member.
- 24. The method of claim 21, wherein the step (a) further comprises the steps of providing an endoluminal stent made of a shape memory material having a pre-defined austenite tubular dimensional state and step (b) is performed while the endoluminal stent is at the pre-defined austenite tubular dimensional state.
- 25. The method of claim 21, wherein the step (a) further comprises the steps of providing a self-expanding endoluminal stent made of a material having an inherent spring tension and the step (b) is performed while the endoluminal stent is at a radially unstrained dimensional state.
- 26. A method for making a stent-graft, comprising the steps of:
c. transforming a shape memory endoluminal stent from a substantially austenite phase to a temperature-induced martensite phase; d. reducing the diametric dimension of the endoluminal stent in its temperature-induce martensite phase from a larger diametric dimension to a reduced diametric dimension; e. constraining the endoluminal stent in a temperature-induced martensite phase and in its reduced diametric dimension with a substantially monolithic covering of expanded polytetrafluoroethylene circumferentially covering at least a portion of the longitudinal extent of the endoluminal stent, the substantially monolithic covering of expanded polytetrafluoroethylene being radially deformable to release constraining force exerted on the endoluminal stent.
- 27. A method for making an encapsulated stent-graft, comprising the steps of:
a. cooling an endoluminal stent made of a shape memory material and having a pre-determined austenite tubular dimensional state to a temperature below the martensite transformation temperature of the shape memory alloy; b. deforming the endoluminal stent at a temperature below Ms to reduce the diametric dimension of the endoluminal stent to a diameter suitable for endoluminal delivery thereof, the deformation being performed substantially without plastic deformation of the endoluminal stent; c. concentrically engaging the deformed endoluminal stent in its deformed martensite state about a first layer of longitudinally expanded polytetrafluoroethylene; d. concentrically engaging a second layer of longitudinally expanded polytetrafluoroethylene about the deformed endoluminal stent and the first layer of longitudinally expanded polytetrafluoroethylene; e. applying a circumferential pressure about the first and second layers of longitudinally expanded polytetrafluoroethylene and the deformed endoluminal stent; and f. exposing the first and second layers of longitudinally expanded polytetrafluoroethylene and endoluminal stent in its reduced diametric state to a temperature above the crystalline melt point of the polytetrafluoroethylene for a period of time sufficient to monolithically join the first and second layers of polytetrafluoroethylene to one another the endoluminal stent forming a single substantially homogeneous layer of expanded polytetrafluoroethylene.
- 28. A method for making an encapsulated stent-graft, comprising the steps of:
a. an endoluminal stent made of a pseudoelastic material and having a pre-determined austenite tubular dimensional state at a temperature above the martensite transformation temperature of the shape memory alloy; b. deforming the endoluminal stent at a temperature above Af, but below Md to reduce the diametric dimension of the endoluminal stent to a diameter suitable for endoluminal delivery thereof, the deformation being performed substantially without plastic deformation of the endoluminal stent; c. concentrically engaging the deformed endoluminal stent in its reduced diametric state about a first layer of longitudinally expanded polytetrafluoroethylene; d. concentrically engaging a second layer of longitudinally expanded polytetrafluoroethylene about the deformed endoluminal stent and the first layer of longitudinally expanded polytetrafluoroethylene; e. applying a circumferential pressure about the first and second layers of longitudinally expanded polytetrafluoroethylene and the endoluminal stent; and f. exposing the first and second layers of longitudinally expanded polytetrafluoroethylene and endoluminal stent in its reduced diametric state to a temperature above the crystalline melt point of the polytetrafluoroethylene for a period of time sufficient to monolithically join the first and second layers of polytetrafluoroethylene to one another through the endoluminal stent forming a single substantially homogeneous layer of expanded polytetrafluoroethylene.
- 29. A method for making an encapsulated stent-graft, comprising the steps of:
a. concentrically engaging the endoluminal stent in its enlarged state about a first layer of longitudinally expanded polytetrafluoroethylene; b. concentrically engaging a second layer of longitudinally expanded polytetrafluoroethylene about the enlarged endoluminal stent and the first layer of longitudinally expanded polytetrafluoroethylene; c. applying a circumferential pressure about the layers of longitudinally expanded polytetrafluoroethylene and the endoluminal stent; and d. exposing the layers of longitudinally expanded polytetrafluoroethylene locally in the void areas of the endoluminal stent in its reduced diametric state to a temperature above the crystalline melt point of the polytetrafluoroethylene for a period of time sufficient to monolithically join the first and second layers of polytetrafluoroethylene to one another through the endoluminal stent forming a single substantially homogeneous layer of expanded polytetrafluoroethylene in the void areas.
- 30. A method for making an encapsulated stent-graft, comprising the steps of:
a. an endoluminal stent made of a pseudoelastic material and having a pre-determined austenite tubular dimensional state at a temperature above the martensite transformation temperature of the shape memory alloy (Af); b. deforming the endoluminal stent at a temperature above Af, but below Md to reduce the diametric dimension of the endoluminal stent to a diameter suitable for endoluminal delivery thereof, the deformation being performed substantially without plastic deformation of the endoluminal stent; c. concentrically engaging the deformed endoluminal stent in its reduced diametric state about a first layer of longitudinally expanded polytetrafluoroethylene; d. concentrically engaging a second layer of longitudinally expanded polytetrafluoroethylene about the deformed endoluminal stent and the first layer of longitudinally expanded polytetrafluoroethylene; e. applying a circumferential pressure about the first and second layers of longitudinally expanded polytetrafluoroethylene and the endoluminal stent; and f. exposing the first and second layers longitudinally expanded polytetrafluoroethylene locally in the void areas of the endoluminal stent in its reduced diametric state to a temperature above the crystalline melt point of the polytetrafluoroethylene for a period of time sufficient to monolithically join the first and second layers of polytetrafluoroethylene to one another through the endoluminal stent forming a single substantially homogeneous layer of expanded polytetrafluoroethylene in the void areas.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of co-pending patent application Ser. No. 08/508,033 filed Jul. 27, 1995 which is a continuation-in-part of co-pending patent application Ser. No. 08/401,871, filed Mar. 10, 1995, both published as International Publication No. WO 96/28115, published Sep. 19, 1996, and co-pending U.S. patent application Ser. No. 08/794,871, filed Feb. 5, 1997, each of which is expressly incorporated by reference as if fully set forth herein.
Continuation in Parts (3)
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Number |
Date |
Country |
Parent |
08508033 |
Jul 1995 |
US |
Child |
08833797 |
Apr 1997 |
US |
Parent |
08401871 |
Mar 1995 |
US |
Child |
08508033 |
Jul 1995 |
US |
Parent |
08794871 |
Feb 1997 |
US |
Child |
08508033 |
Jul 1995 |
US |