Stanford classification of aortic dissection

Along with the DeBakey classification, the Stanford classification ⁷ is used to separate aortic dissections into those that need surgical repair, and those that usually require only medical management. The Stanford classification divides dissections by the most proximal involvement:

• type A: A affects ascending aorta
  • accounts for ~60% of aortic dissections
  • surgical management
  • may result in:
    • coronary artery occlusion
    • aortic incompetence
    • rupture into the pericardial sac with resulting cardiac tamponade
• type B: B begins beyond brachiocephalic vessels
  • accounts for ~40% of aortic dissections
  • dissection commences distal to the left subclavian artery
  • medical management with blood pressure control

A special case that is neither reflected in the original Stanford nor the DeBakey classification are dissections that involve the aortic arch but not the ascending aorta (between 8 and 15% of all aortic dissections ⁴). The nomenclature of these arch dissections has been incoherent for decades and still is.

American surgical consensus (2020) ⁵ defines types A and B according to the location of the intimal tear (both types with additional qualifiers for proximal and distal extent):

• type A: dissections with a tear in the ascending aorta including a segment with the branching of the brachiocephalic trunk
• type B: all dissections with proximal tear distal to the branching of the brachiocephalic trunk

In contrast, a European surgical consensus document (2018) ⁶ recognizes dissections of the arch without involvement of the ascending aorta as a distinct category, termed "non-A-non-B dissection":

• type A: proximal extent in ascending aorta
• non-A-non-B dissection: retrograde extent or proximal tear in the arch between the brachiocephalic trunk and left subclavian artery
• type B: proximal extent in descending aorta distal to left subclavian artery