Device and method to prevent or treat outflow vein stenosis of an arteriovenous fistula constructed with a synthetic vascular graft

Systems and methods are provided that reduce or prevent the occurrence of NIH, VR and the resulting VS in the VOT of a GAVF. The system may protect the venous outflow tract of a GAVF from the deleterious physical and biological factors that induce: pathological cellular and biochemical responses which cause neointimal hyperplasia, venous remodeling, thrombosis, venous stenosis, and GAVF-vein anastomotic stenosis, including: a fenestrated expandable stent; and a tubular extension extending from the fenestration. The method protects the venous outflow tract of a GAVF from the deleterious physical and biological factors that induce: pathological cellular and biochemical responses which cause neointimal hyperplasia, venous remodeling, thrombosis, venous stenosis, and GAVF-vein anastomotic stenosis, and include steps of inserting the device into a vein to be used as a VOT; expanding the device; and joining the tubular extension of the device to a GAVF.