Brain and lower body protection during aortic arch surgery.

Background: Deep hypothermic circulatory arrest (DHCA) at ≤20°C for aortic arch surgery has been widely used for decades, with or without cerebral perfusion (CP), antegrade (antegrade cerebral perfusion [ACP]), or retrograde. In recent years nadir temperature progressively increased to 26°C-28°C (moderately hypothermic circulatory arrest [MHCA]), adding ACP. Aim of this multicentric study is to evaluate early results of aortic arch surgery and if DHCA with 10 min of cold reperfusion at the same nadir temperature of the CA before rewarming (delayed rewarming [DR]) can provide a neuroprotection and a lower body protection similar to that provided by MHCA + ACP.