Aortic Outcome after Implementation of a Treatment Strategy for Type B Aortic Dissection Involving the Aortic Arch

Objective To evaluate the outcomes achieved after implementing a treatment strategy for non-A non-B (NANB) (B 1-2 D according to the latest consensus document of the Society of Vascular Surgery (SVS) and Society of Thoracic Surgeons (STS) acute aortic dissection (AAD)). Methods This retrospective observational study adhered to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist. All cases of NANB AAD (B 1-2 D) treated at our institution between January 2016 and December 2022 were reviewed. Morbidity, mortality, aortic-related reintervention, and remodeling were analyzed. Results Among 519 cases of acute aortic syndrome, n = 22 (4.2%) patients presented with NANB AAD (B 1-2 D) (n = 16,72.7% men, mean age 61.5 years+/14.7). Eleven cases were managed with best medical treatment (BMT) alone. Among them, one patient (9.1%) died suddenly 2 days after diagnosis for aortic rupture. Frozen elephant trunk procedure (FET) was required in the remaining 11 patients: 7 (31.8%) needed emergent operation for risks of impending aortic rupture or retrograde aortic dissection extension, and 4 (26.7%) underwent delayed surgery within a month from initial presentation. Overall, in-hospital mortality was 9.1% with both FET and BMT. At a median follow-up of 40 months (range 2 days-200 months) no other deaths occurred. A statistically significant differences in the rate of false lumen thrombosis (100% vs 55.5%, P = 0.033), and a significant positive aortic remodeling in zone 3 (P < 0.001) and 4 (P = 0.038) were reported in operated versus medically managed patients. Conclusions The best treatment for NANB is not established. We advocate for medical stabilization with an operative approach that favors open surgery in the acute post dissection period, promotes aortic remodeling, and carries acceptable risk in centers where FET is performed routinely.