Aortic dissection reconsidered: type, entry site, malperfusion classification adding clarity and enabling outcome prediction.

Abstract

Aortic dissection is complex. Imaging and treatment modalities are evolving, demanding a more differentiated but pragmatic dissection classification. Our goal was to provide a new practical classification system including Type of dissection, location of the tear of the primary Entry and Malperfusion (TEM). We extended the Stanford dissection classification (A and B) by adding non-A non-B aortic dissection, the location of the primary entry tear (E) and malperfusion (M). A 0 was added if the primary entry tear was not visible; 1, if it was in the ascending aorta; 2, if it was in the arch; and 3, if it was in the descending aorta (E0, E1, E2, E3). We added 0 if malperfusion was absent; 1, if coronary arteries; 2, if supra-aortic vessels; and 3, if visceral/renal and/or a lower extremity was affected (M0, M1, M2, M3). Plus (+) was added if malperfusion was clinically present and minus (-) if it was a radiological finding. The new classification system was analysed in 357 patients retrospectively; distribution was 59%, 31% and 10% for A, B and non-A non-B dissections. The in-hospital mortality rate was 16%, 5% and 8% (P = 0.01). Postoperative stroke occurred in 14%, 1% and 3% (P < 0.001). The in-hospital mortality rate was 22%, 14%, 40% and 0% in A E0, E1, E2 and E3 (P = 0.023), respectively. Two years after the onset of dissection, the lowest survival rate was observed in A, followed by non-A non-B and B (83 ± 3% vs 88 ± 6% vs 93 ± 3%; P = 0.019). The new practical TEM aortic dissection classification system adds clarity regarding the extent of the disease process, enhances awareness of the disease mechanism, aids in decision-making regarding the extent of repair and helps in anticipating outcome.