Class 1

Classical aortic dissection with an intimal flap between true and false lumen

Class 2

Medial disruption with formation of Intramural haematoma/haemorrhage

Class 3

Discrete/subtle dissection without haematoma, eccentric bulge at tear site

Class 4

Plaque rupture leading to aortic ulceration, penetrating aortic atherosclerotic ulcer with surrounding haematoma, usually subadventitial

Class 5

Iatrogenic and traumatic dissection