Should the DeBakey Classification Be Reconsidered for Acute Type A Aortic Dissection?

Abstract

The DeBakey classification remains a cornerstone for describing acute type A aortic dissection, yet it is unclear whether types 1 and 2 represent distinct pathophysiologic entities or merely different extents of the same condition. This study evaluated detailed morphologic features to explore whether these subtypes arise from divergent structural and biomechanical conditions of the ascending aorta. We performed a retrospective analysis of 429 patients surgically treated for acute type A dissection at Siena University Hospital (2000-2025). Only cases with clearly classifiable DeBakey type 1 (n = 258) or type 2 (n = 171) morphology were included. Patients with type 1 dissection were significantly younger than those with type 2 (65.5 vs 77 years; P < .001). Type 2 dissections occurred in larger (56.2 vs 46.7 mm; P < .001) and longer (128 vs 109 mm; P < .001) ascending aortas, reflected in higher TAIPAN scores (2.4 vs 0.7; P < .001), indicating greater geometric deformation. Tear morphology also differed; transverse tears predominated in type 1 (85%), whereas longitudinal tears were characteristic of type 2 (61%; P < .001). Cardiovascular risk factors, anthropometric variables, and congenital and genetic markers were comparable between groups. DeBakey types 1 and 2 demonstrate distinct morphologic and geometric profiles. Type 2 dissections are associated with larger and more elongated aortas, whereas type 1 dissections arise in smaller and less remodeled vessels. These findings challenge diameter-based prevention strategies for type 1 and support incorporating aortic length and geometric indices into risk assessment. Preservation of the DeBakey classification remains clinically relevant and should not be abandoned in favor of overly unified classification schemes.