ObjectiveHybrid total arch replacement (HTAR) was an alternative for type A aortic dissection (TAAD). This study aimed to evaluate the clinical and radiographical outcomes of HTAR for TAAD and to evaluate the clinical outcomes of performing this procedure under mild hypothermia.MethodsA total of 209 patients who underwent HTAR for TAAD were retrospectively analyzed and stratified into mild (n = 48) and moderate (n = 161) hypothermia groups to evaluate the effects of mild hypothermia on the clinical outcomes. Long-term clinical outcomes were evaluated by the overall survival and adverse aortic events (AAEs). A total of 176 patients with preoperative and at least one-time postoperative aortic computed tomography angiography in our institute were included for evaluating the late aortic remodeling (aortic diameter and false lumen thrombosis).ResultsThe median follow-up period was 48.3 (interquartile range [IQR] = 28.4–73.7) months. The overall survival rate was 88.0, 83.2, and 77.1% at the 1, 5, and 10 years, respectively, and in the presence of death as a competing risk, the cumulative incidence of AAEs was 4.8, 9.9, and 12.1% at the 1, 5, and 10 years. The aortic diameters were stable in the descending thoracic and abdominal aorta (P > 0.05 in all the measured aortic segments). A total of 100% complete false lumen thrombosis rate in the stent covered and distal thoracic aorta were achieved at 1 year (64/64) and 4 years (18/18), respectively after HTAR. The overall composite adverse events morbidity and mortality were 18.7 and 10.0%. Mild hypothermia (31.2, IQR = 30.2–32.0) achieved similar composite adverse events morbidity (mild: 14.6 vs. moderate: 19.9%, P = 0.41) and early mortality (mild: 10.4 vs. moderate: 9.9%, P = 1.00) compared with moderate hypothermia (median 27.7, IQR = 27–28.1) group, but mild hypothermia group needed shorter cardiopulmonary bypass (mild: 111, IQR = 93–145 min vs. moderate: 136, IQR = 114–173 min, P < 0.001) and aortic cross-clamping (mild: 45, IQR = 37–56 min vs. moderate: 78, IQR = 54–107 min, P < 0.001) time.ConclusionHybrid total arch replacement achieved desirable early and long-term clinical outcomes for TAAD. Performing HTAR under mild hypothermia was as safe as under moderate hypothermia. After HTAR for TAAD, dissected aorta achieved desirable aortic remodeling, presenting as stable aortic diameters and false lumen complete thrombosis. In all, HTAR is a practical treatment for TAAD.