An endovascular prosthesis includes a tubular body and a mobile external coupling. The tubular body includes a graft material and stents coupled thereto which forms a lumen therethrough. The mobile external coupling extends outwardly from the tubular body. The mobile external coupling includes a graft material and is generally frustoconically shaped. The mobile external coupling includes a base coupled to the tubular body, a top spaced from the tubular body, and a coupling lumen disposed between the base and the top, wherein the coupling lumen is in flow communication with the body lumen. A coupling deployment device is coupled to the coupling graft material to provide an extension force to extend the mobile external coupling from a collapsed configuration against the tubular body to an extended position wherein the mobile external coupling extends from the tubular body.
