A stent graft device (10) for treatment of a Type A dissection comprises a first tubular portion (12) for placement into the ascending aorta, a second tubular portion (14) for extending around the thoracic arch and down the descending aorta and a bypass tube (24) allowing perfusion during an operation. To allow blood flow to the arteries of the thoracic arch, the second tubular portion (14) has an elongate recess (32) with a recess lumen (35) which is fluidically connected to the lumen (28) of the second tubular portion by one or more apertures (36). The second tubular portion (14) has self expanding stents (30) along it and the first tubular portion (12) is corrugated and unstented.
