A hybrid stent graft device for treatment of a Type A dissection having a first tubular portion for placement into the ascending aorta and a second tubular portion for extending around the thoracic arch and down the descending aorta is disclosed. The first tubular portion is connectable to the aorta between the sinotubular junction and the brachiocephalic artery so that it essentially replaces the ascending aorta. A temporary bypass tube allows perfusion during an operation. The second tubular portion has an elongate recess outside of the second tubular portion and an aperture defining a fluid flow path into the recess. The recess is intended to engage an outer curve of the thoracic arch to enable blood flow into the arteries of the thoracic arch. An introduction device in combination with the hybrid stent graft described above is also disclosed.