Impact of new classification from the Society for Vascular Surgery and Society of Thoracic Surgeons on acute Stanford type A aortic dissection.

Objectives: The Stanford classification categorizes aortic dissection based on ascending aortic involvement, whereas the newer Society for Vascular Surgery/Society of Thoracic Surgeons (SVS/STS) classification emphasizes tear location. Thus, traditional Stanford type A dissection may be an SVS/STS type A dissection or SVS/STS type B0 dissection. We evaluated the impact of SVS/STS classification on perioperative characteristics and outcomes after acute Stanford type A dissection repair.

Methods: We retrospectively reviewed 794 patients undergoing acute Stanford type A dissection repair between January 1999 and March 2025, excluding those with unidentified entry tears (SVS/STS type I). Perioperative variables and outcomes were compared between SVS/STS type A (n=632) and type B0 (n=162).

Results: SVS/STS type B0 patients had lower rates of malperfusion and hypotension but larger arch, descending, and abdominal aortic diameters. Operative mortality was similar between groups (13.9% vs. 14.8%, P=0.778). Long-term survival did not differ significantly (10-year survival: 59.3% vs. 54.5%, P=0.277). However, freedom from distal aortic reintervention was significantly lower in the SVS/STS type B0 group (76.2% vs. 65.3% at 10 years, P=0.008).

Conclusion: The SVS/STS classification identifies distinct subgroups within Stanford type A dissection. SVS/STS type B0 dissections present with more stable hemodynamics but larger aortic dimensions and higher distal reintervention rates. This classification provides valuable prognostic information for both early and late outcomes.