An endovascular prosthesis comprising a first end section, a second end section and a midsection. The midsection has a diameter less than the diameter of the first end section and the second end section. At least the first end section and the second end section have lateral support preferably in the form of a stent which may also act as anchoring. The reduced diameter midsection is provided with at least one side port which is adapted to be connected to a branch endograft to provide a connection between the side port and the native branch artery. The side ports are arranged to correspond with the native branch arteries and are provided with radiographic markers at their proximal and distal ends. The side ports with the radiographic markers provide an effective means of making the connection to the native branch by a branch endograft without having to align the side ports exactly to the branch arteries and without kinking of the side ports.