An expandable prosthetic device and method of delivery that allows the initial placement of multiple guidewires into selected target sites. The prosthesis includes a main body device. This main body device has a separate side branch guidewire lumen that passes through the main body device and through a side opening in the main body device. As the main body device is advanced, the side opening is self guided (by the side branch guidewire) and self-aligns to the side branch vessel ostium. The main body device is then deployed, leaving the side branch guidewire in place. A side branch device is then advanced along the side branch guidewire through the main body device, through the side wall opening and into the native side branch vessel. The side branch device can then be deployed to engage the main body device and the native side branch vessel.
