Intraoperative Electroencephalogram-Guided Deep Hypothermia Plus Antegrade and/or Retrograde Cerebral Perfusion during Aortic Arch Surgery

Background A number of intraoperative tools are used for brain monitoring in aortic arch surgery. We rely on intraoperative electroencephalogram (EEG) to guide deep hypothermic circulatory arrest. Methods Between July 2012 and June 2014, 157 patients underwent aortic arch surgery with deep hypothermic circulatory arrest performed by a single surgeon. Intraoperative EEG was used in 141 patients (89.8%). Our intraoperative strategy was to continue systemic cooling until no electrical waves were observed on the EEG. Once we confirmed electroencephalographic silence, we induced deep hypothermic circulatory arrest for aortic arch reconstruction. Retrograde cerebral perfusion was also used during hemiarch and distal arch replacements. Antegrade cerebral perfusion was added to total arch replacements. Results Patients' mean age was 59.1 ± 14.6 years. Hemiarch replacement was performed in 100 (63.7%), total arch replacement in 28 (17.8%), and distal arch replacement in 29 (18.5%). There were 30 urgent or emergency cases (19.1%). Circulatory arrest time was 28.8 ± 15.3 minutes. Thirty-day mortality occurred in four patients (2.5%). Postoperative stroke was diagnosed in five patients (3.2%). Major stroke led to 30-day mortality in two patients whose intraoperative EEG had shown abnormal recovery after systemic rewarming. One hundred thirty-five patients (95.7%) had normal recovery of EEG. Of these, three (2.2%) developed minor stroke consisting of minor hemiplegia. Conclusions Intraoperative EEG is a reliable monitoring tool for safe circulatory arrest.