a venous polytetrafluoroethylene graft with integral access port system . the graft may have one , two , or more ports , which then exits the skin . the prosthesis may be made of fluoropolymer tubing fabricated in such a way as to involve several performance features . the graft may have holes for suturing , anchoring , or bio - integration to the artery . the ports have natural acting restrictions or valves at the graft juncture , throughout the implanted part body of the device and at the exit site . the ports are also naturally self - purging . a port may also incorporate a redundant hermetic hemostatic valve and closure system at the exit site .