Prostheses and methods of making the same are provided. The prosthesis (10) has an internal branch configuration. A trough (50) or branch opening is at least partially defined by a trough wall (52) extending into a main lumen from a sidewall (25) of the prosthesis. The internal branch extends from the trough (50) within the main lumen towards one of the outflow end of the graft body (20) in an helical, retrograde arrangement. Other arrangements are described. The prosthesis (10) may include a scalloped fenestration (80) having a width larger than the trough (50). The trough (50) may be positioned along a tapered region (20B) of the prosthesis. The trough (50) and internal branch may be made from the same graft material. The trough (50) and internal branch, in addition to the main graft body, may be made from the same graft material.