Impact of core temperature management and postoperative continuous renal replacement therapy in extensive aortic arch repair for type A dissection.

BACKGROUND: Continuous renal replacement therapy (CRRT) represents a critical complication following extensive aortic arch repair for type A aortic dissection (TAAD), significantly influencing patient outcomes. This study evaluates the impact of different hypothermic circulatory arrest (HCA) temperature strategies on postoperative CRRT requirements. METHODS: A total of 1,283 TAAD patients who underwent total arch replacement (TAR) with frozen elephant trunk (FET) procedure were retrospectively enrolled [2010-2018]. Patients were divided into CRRT (N=123) and non-CRRT (N=1,160) groups. Core temperature during HCA was categorized into deep hypothermia (DH) (≤20 ℃), low-moderate hypothermia (LMH) (20.1-24 ℃), high-moderate hypothermia (HMH) (24.1-28 ℃), and mild hypothermia (MH) (>28 ℃). RESULTS: The CRRT group exhibited significantly higher early mortality (38.2% vs. 3.7%, P<0.001) and lower long-term survival during a 6.02-year follow-up. Multivariate analysis revealed a significant interaction between core temperature and cardiopulmonary bypass (CPB) time (P=0.02). Higher temperature groups demonstrated protective effects compared to DH (P for trend =0.001). However, as CPB time substantially prolongs, the protective effect of higher core temperatures appears to gradually diminish, and the trend may even reverse. CONCLUSIONS: Higher core temperatures are associated with reduced CRRT risk during TAR with FET procedure. However, this association appears to be modified by CPB duration, and caution is warranted regarding potential renal injury associated with increased core temperatures in complex surgeries with prolonged CPB time.