There is dissection of the aorta involving the aortic root, ascending and descending aorta and abdominal aorta to just below the origin of the coeliac axis (Stanford type A).
The dissection flap involves the root of the brachiocephalic trunk and left common carotid artery. There is also a dissection flap extending into the left subclavian artery to the level of the infra-clavicular vessel.