Abstract: An improved method and apparatus is provided for extruding ePTFE tube for use in medical applications. A tube of PTFE is extruded, preferably in an extrusion process, using counter-rotated die components. The die component is maintained at a constant temperature during processing. The resulting green tube has enhanced fibrous state formation in a direction perpendicular to the direction of extrusion. The PTFE green tube is then subjected to secondary operations such as stretching and expansion to yield medical product. The ePTFE tube structure is defined by nodes interconnected by elongate fibrils. Both the nodes and fibrils are substantially randomly tilted with respect to the longitudinal axis of the tube. This particular structure yields a tube which exhibits a high degree of radial tear strength useful in medical applications.

Abstract: An implantable microporous ePTFE tubular vascular graft exhibits long-term patency, superior radial tensile strength, reduction in tear propagation, and increases in suture retention strength and crush resistance. The graft includes an ePTFE tubular structure having a preselected microporous structure. The tubular structure is wrapped externally with a PTFE yarn in a helical fashion. The helical wrap of yarn is bonded to the exterior surface of the tubular structure by application of heat or heat in combination with force to form a composite structure which substantially maintains the porosity of the underlying tubular structure while increasing the suture retention strength, radial tensile strength, crush resistance, and tear propagation resistance.

Abstract: An implantable microporous ePTFE tubular vascular graft exhibits long term patency, superior radial tensile strength and suture hole elongation resistance. The graft includes a first ePTFE tube and a second ePTFE tube circumferentially disposed over the first tube. The first ePTFE tube exhibits a porosity sufficient to promote cell endothelization tissue ingrowth and healing. The second ePTFE tube exhibits enhanced radial strength in excess of the radial tensile strength of the first tube.

Abstract: An implantable microporous ePTFE tubular vascular graft exhibits long term patency, superior radial tensile strength and suture hole elongation resistance. The graft includes a first ePTFE tube and a second ePTFE tube circumferentially disposed over the first tube. The first ePTFE tube exhibits a porosity sufficient to promote cell endothelization tissue ingrowth and healing. The second ePTFE tube exhibits enhanced radial strength in excess of the radial tensile strength of the first tube. The stent provides patency to the endoprosthesis.

Abstract: An improved method is provided for extruding ePTFE tube (12) for use in medical applications. A tube (12) of PTFE is extruded, preferably in an extrusion process, using counter-rotated die components (22, 26). The die component (16) is maintained at a constant temperature during processing. The resulting green tube (12) has enhanced fibrous state formation in a direction perpendicular to the direction of extrusion. The PTFE green tube (12) is then subjected to secondary operations such as stretching and expansion to yield medical product. The ePTFE tube (12) structure is defined by nodes interconnected by elongate fibrils. Both the nodes and fibrils are substantially randomly tilted with respect to the longitudinal axis of the tube (12). This particular structure yields a tube (12) which exhibits a high degree of radial tear strength useful in medical applications.

Abstract: An implantable microporous ePTFE tubular vascular graft exhibits long term patency, superior radial tensile strength and suture hole elongation resistance. The graft includes a first ePTFE tube and a second ePTFE tube circumferentially disposed over the first tube. The first ePTFE tube exhibits a porosity sufficient to promote cell endothelization tissue ingrowth and healing. The second ePTFE tube exhibits enhanced radial strength in excess of the radial tensile strength of the first tube.

Abstract: An implantable microporous ePTFE tubular vascular graft exhibits long-term patency, superior radial tensile strength, reduction in tear propagation, and increases in suture retention strength and crush resistance. The graft includes an ePTFE tubular structure having a preselected microporous structure. The tubular structure is wrapped externally with a PTFE yarn in a helical fashion. The helical wrap of yarn is bonded to the exterior surface of the tubular structure by application of heat or heat in combination with force to form a composite structure which substantially maintains the porosity of the underlying tubular structure while increasing the suture retention strength, radial tensile strength, crush resistance, and tear propagation resistance.