Figure 3. Aortic arch zone distribution and Stanford classification of the ascending aorta and brachiocephalic artery (zone 0), left common carotid artery (zone 1), left subclavian artery (zone 2), and descending aorta (zone 3).

Type A dissections commence from the ascending aorta involving the arch arteries. Type B dissections commence distal to the left subclavian artery.