A stent graft comprising an elongate main tubular body of a biocompatible graft material is disclosed. The main tubular body comprises a main lumen, a distal end and a proximal end； and an elongate tubular bridge of a biocompatible graft material. The elongate tubular bridge extends around a portion of the main tubular body so as to form a bridging lumen bridging between two circumferentially spaced-apart openings within the main tubular body. The tubular bridge has at least two fenestrations. The tubular bridge comprises concertinaed graft material.
