Radially expandable tubular polytetrafluoroethylene grafts and method of making same
First Claim
1. A continuous tubular structure comprising an expanded polytetrafluoroethylene material having a predetermined wall thickness and a microstructure characterized by a plurality of nodes interconnected by fibrils, the fibrils having an orientation substantially parallel to a longitudinal axis of the polytetrafluoroethylene tubular material throughout the wall thickness of the tubular structure and the nodes having a longitudinal axis substantially perpendicular to the longitudinal axis of the polytetrafluoroethylene material, the polytetrafluoroethylene material of the tubular structure being capable of undergoing radial deformation from an original unexpanded diameter of the tubular structure to a larger diameter of the tubular structure by application of a positive pressure applied through the lumen of the tubular structure and radially outward therefrom which causes a plurality of the nodes in the microstructure to undergo elongation along the longitudinal axis of the nodes, while substantially retaining an average internodal distance throughout the wall thickness of the radially deformed tubular structure.
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Accused Products
Abstract
Tubular ePTFE materials which are capable of being radially expanded under the influence of a radially outward force applied from the lumen of the ePTFE tubular material to substantially uniformly radially deform the ePTFE material. The ePTFE material is radially expandable to a diameter 700% its unexpanded diameter under the influence of pressures less than 6 atm while retaining the structural integrity of the ePTFE microstructure. Conservation of the structural integrity of the ePTFE material is determined by conservation of the ePTFE microstructure structural integrity.
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Citations
14 Claims
- 1. A continuous tubular structure comprising an expanded polytetrafluoroethylene material having a predetermined wall thickness and a microstructure characterized by a plurality of nodes interconnected by fibrils, the fibrils having an orientation substantially parallel to a longitudinal axis of the polytetrafluoroethylene tubular material throughout the wall thickness of the tubular structure and the nodes having a longitudinal axis substantially perpendicular to the longitudinal axis of the polytetrafluoroethylene material, the polytetrafluoroethylene material of the tubular structure being capable of undergoing radial deformation from an original unexpanded diameter of the tubular structure to a larger diameter of the tubular structure by application of a positive pressure applied through the lumen of the tubular structure and radially outward therefrom which causes a plurality of the nodes in the microstructure to undergo elongation along the longitudinal axis of the nodes, while substantially retaining an average internodal distance throughout the wall thickness of the radially deformed tubular structure.
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14. A tubular expanded polytetrafluoroethylene member having a determined wall thickness, comprising a material microstructure characterized by a plurality of nodes interconnected by fibrils, the fibrils having an orientation substantially parallel to a longitudinal axis of the tubular expanded polytetrafluoroethylene member and throughout the redetermined wall thickness thereof and the nodes having a longitudinal axis substantially perpendicular to the longitudinal axis of the tubular expanded polytetrafluoroethylene member, the tubular expanded polytetrafluoroethylene member being capable of undergoing radial deformation under an influence of a positive pressure of less than or equal to about 6 atm applied through the lumen of the polytetrafluoroethylene tubular material and directed radially outward therefrom which acts to cause at least some of the nodes to elongate along their longitudinal axis while substantially retaining an average internodal distance throughout the microstructure of the radially deformed tubular expanded polytetrafluoroethylene member which is substantially the same as that of the non-radially deformed tubular expanded polytetrafluoroethylene member.
Specification