Optimal circulatory arrest temperature for total aortic arch replacement: Outcomes of neurological complications

Objective: The optimal hypothermic circulatory arrest temperature during total arch replacement and the impact of hypothermic circulatory arrest temperature on postoperative neurological complications are still uncertain. The aim of this study is to explore the impact of hypothermic circulatory arrest temperature on short-term postoperative outcomes, especially neurological complications, for patients who undergo total arch replacement. Methods: We retrospectively analyzed data of 2351 patients who underwent total arch replacement at 1 of 7 selected aortic centers from January 2016 to June 2023. Restricted cubic splines and subgroup analyses were performed to determine the relation between temperature and outcomes under different cerebral perfusion methods, cannulation strategies, diagnoses, and surgical timings. Results: The overall in-hospital mortality was 6.2% (n = 146). The incidence of stroke, paraplegia, and total-arch composite outcome was 6.0% (n = 142), 2.8% (n = 65), and 21.0% (n = 494), respectively. The average hypothermic circulatory arrest temperature was 25.9 °C ± 1.9 °C, and the median circulatory arrest time was 23 minutes (Q1, Q3: 18, 30). Adjusted restricted cubic splines showed the lowest incidence of stroke, paraplegia, and total-arch composite outcome at temperatures of 26.6 °C, 27.4 °C, and 26.8 °C, respectively, but without statistical significance. In subgroup analysis, the unilateral antegrade cerebral perfusion group revealed a significant nonlinear relation between the hypothermic circulatory arrest temperature and the risk of stroke, and the lowest risk was at 26.5 °C. Other subgroup analyses did not reveal a significant nonlinear relation between temperature and outcomes. Conclusions: For patients undergoing total arch replacement with unilateral antegrade cerebral perfusion, cooling to a temperature of 26 °C to 27 °C was associated with the lowest incidence of stroke.