A prosthesis, introducer device and a method for repair of an aortic aneurysm which is positioned at least partially in the ascending aorta (62). The prosthesis (3) has a proximal end (15) and a distal end (5) and is formed from a biocompatible material, the proximal end is adapted to be surgically fastened adjacent and around the aortic heart valve (60) of a patient and the distal end is adapted to extend into the descending aorta (66). The distal end has a distally extending exposed self-expanding stent (9). The introducer device can be deployed through an incision (75) in the thoracic arch (64) and extend down the descending aorta to place the distal end of the prosthesis first and then removed so that the proximal end of the prosthesis can be sutured in place around the aortic heart valve (60).