4th June 2026

Classifications

Stanford

• Stanford Type A – A tear that involves the ascending aorta, even if it starts elsewhere. It is proximal to the brachiocephalic artery.
• Stanford Type B – A tear that involves the descending aorta only. Its origin is distal to the left subclavian artery.

Figure 4: Stanford classifications of dissection 

Image Source: Wikimedia Commons (2020), ECG AVNRT, Licenced under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Aortic_dissection_types.jpg (Accessed: 27 April 2026)

DeBakey

• DeBakey Type 1 – A dissection that involves the whole aorta – originating either in the ascending, arch or descending areas. 
• DeBakey Type 2 – A dissection that originates in and involves only the ascending aorta/arch. 
• DeBakey Type 3 – A dissection that originates in the descending aorta. 
  • 3a – Extends to above the diaphragm, and either proximal or distal to the left subclavian artery.
  • 3b – Extends to below the diaphragm, and distal to the left subclavian artery.

Svensson

This classification has been developed more recently to include aortic ulcers, intramural haematomas and iatrogenic causes.  

• Class 1 – A flap is created between the false lumen and true lumen – A ‘classic’ dissection.
• Class 2 – Caused by an intramural haematoma.
• Class 3 – A limited dissection with a bulge at tear site, and no haematoma.
• Class 4 – A atherosclerotic penetrating ulcer with a haematoma surrounding it.
• Class 5 – Traumatic or iatrogenic dissection.

Classification by timeframe

• Hyperacute – An aortic dissection <24 hours since initial symptoms 
• Acute – 1-14 days 
• Subacute — 15-90 days 
• Chronic >90 days