A system comprising: a prosthesis comprising: a graft including: a generally tubular body of biocompatible material; a proximal end , a distal end , and a lumen extending therebetween; a proximal portion having a first diameter; a distal portion having a second diameter less than the first diameter; a tapered portion between the proximal portion and the distal portion; first and second branches having proximal regions disposed proximal to, or within, the tapered portion and having distal regions extending toward the distal end of the graft; the system including first and second preloaded wire segments, the first wire segment passing through an end opening at the distal region of the first branch, extending proximally within a lumen of the first branch, exiting an end opening at the proximal region of the first branch and extending proximally within the lumen of the prosthesis to exit an end opening at the proximal end of the prosthesis, the second wire segment passing through an end opening at the proximal end of the prosthesis, extending distally within the lumen of the prosthesis, passing through an end opening at the proximal region of the second branch, extending distally within a lumen of the second branch, and passing through an end opening at the distal region of the second branch to exit the prosthesis and extend distally external to the prosthesis. a prosthesis comprising: a graft including: a generally tubular body of biocompatible material; a proximal end , a distal end , and a lumen extending therebetween; a proximal portion having a first diameter; a distal portion having a second diameter less than the first diameter; a tapered portion between the proximal portion and the distal portion; first and second branches having proximal regions disposed proximal to, or within, the tapered portion and having distal regions extending toward the distal end of the graft; a graft including: a generally tubular body of biocompatible material; a proximal end , a distal end , and a lumen extending therebetween; a proximal portion having a first diameter; a distal portion having a second diameter less than the first diameter; a tapered portion between the proximal portion and the distal portion; first and second branches having proximal regions disposed proximal to, or within, the tapered portion and having distal regions extending toward the distal end of the graft; a generally tubular body of biocompatible material; a proximal end , a distal end , and a lumen extending therebetween; a proximal portion having a first diameter; a distal portion having a second diameter less than the first diameter; a tapered portion between the proximal portion and the distal portion; first and second branches having proximal regions disposed proximal to, or within, the tapered portion and having distal regions extending toward the distal end of the graft; the system including first and second preloaded wire segments, the first wire segment passing through an end opening at the distal region of the first branch, extending proximally within a lumen of the first branch, exiting an end opening at the proximal region of the first branch and extending proximally within the lumen of the prosthesis to exit an end opening at the proximal end of the prosthesis, the second wire segment passing through an end opening at the proximal end of the prosthesis, extending distally within the lumen of the prosthesis, passing through an end opening at the proximal region of the second branch, extending distally within a lumen of the second branch, and passing through an end opening at the distal region of the second branch to exit the prosthesis and extend distally external to the prosthesis. <EOS>