Safety of Moderate Hypothermia With Antegrade Cerebral Perfusion in Total Aortic Arch Replacement

Abstract

Total aortic arch replacement (TOTAL) is a complicated operation and has traditionally required deep hypothermic circulatory arrest. In this study, the impact of moderate hypothermic circulatory arrest (MHCA) and antegrade cerebral perfusion (ACP) for TOTAL were examined. The ARCH International aortic database was queried and 3,265 patients undergoing TOTAL using ACP were identified. Patients were divided into groups based on lowest cooling temperature: MHCA (20° to 28°C) or deep hypothermia (DHCA) (12° to 20°C). Propensity-matched scoring using 15 variables was used in 669 matched pairs. Multivariable analyses were performed. In the unmatched cohort, more patients underwent MHCA (2,586; 79.2%) who were also younger (p< 0.001) and more frequently underwent emergent operations (p < 0.001) than DHCA patients. For the propensity-matched patients, there were significant differences in cardiopulmonary bypass (CPB) time (MHCA 200 minutes versus DHCA 243 minutes, p < 0.001), aortic crossclamp time (MHCA 120 minutes versus DHCA 142 minutes, p<0.001), and cerebral perfusion time (MHCA 63 minutes versus DHCA 58 minutes, p < 0.001). Of note, there was no difference in neurologic outcomes nor in-hospital mortality for the two temperature groups. Multivariable analysis of risk factors for mortality included CPB time (odds ratio [OR] 1.006; p < 0.001), concomitant mitral valve surgery (OR 3.070; p= 0.003), emergent operation (OR 2.924; p < 0.001), and poor ejection fraction (OR 3.133; p= 0.011). Independent risk factors for stroke included coronary artery disease (OR 1.856; p < 0.001), cerebral vascular disease (OR 2.172; p<0.001), emergent operation (OR 2.109; p < 0.001), and CPB time (OR 1.004; p < 0.001). In this series, TOTAL with MHCA and ACP can be safely performed with acceptable operative risk. MHCA and ACP represent an effective strategy for TOTAL and may obviate the need for DHCA.