An anastomosis device for facilitating sutureless side-to-side arteriovenous fistula creation and maintenance of patency thereof is presented. The device comprises two device halves each containing an anastomosis window which is in fluid connection with an interior lumen of the device. Further, the device comprises a pair of vessel joining portions in which the bounds of the fistula are created. The invention also has an embodiment wherein a method of joining a vein and an artery in order to create a fistula is presented.
