Devices, systems, and methods for implanting expandable prostheses in the body lumens rely on stapling or anchoring the prostheses with separately introduced fasteners. The prostheses may be self-expanding or balloon expandable, and may include a single lumen or more than one lumen. After initial placement, a stapling system is introduced within the expanded prosthesis to deploy a plurality of fasteners to at least one prosthesis end. The stapling system may apply a force to the prosthesis to modify the shape of the prosthesis to conform to the shape of the vessel wall. The stapling system can be deflected in one or more distinct steerable segments. A lumen extension or lumens may be coupled to the prosthesis to extend the reach of the prosthesis within the implantation site. Fasteners may also be applied to the lumen extensions.
