Electroencephalography During Hemiarch Replacement With Moderate Hypothermic Circulatory Arrest.
BACKGROUND
This study aimed to characterize intraoperative electroencephalography (EEG) during moderate hypothermic circulatory arrest (MHCA) with selective antegrade cerebral perfusion (SACP), which has not been described previously.


METHODS
This was a single-institution retrospective study of patients undergoing aortic hemiarch replacement using MHCA (temperatures <28°C at circulatory arrest [CA]) and unilateral SACP with EEG monitoring from July 1, 2013 to November 1, 2014. The EEG pattern was determined before and immediately after CA, as well as after establishment of SACP. Patient and procedural characteristics and outcomes were determined and compared after stratification by the presence of ischemic EEG changes.


RESULTS
The study included 71 patients. Before CA, 47 patients (66%) demonstrated a continuous EEG pattern, with or without periodic complexes, and 24 (34%) had a burst suppression EEG pattern. Immediately after CA, abrupt loss of electrocerebral activity occurred in 32 patients (45%), suggestive of cerebral ischemia. Establishment of unilateral SACP rapidly restored electrocerebral activity in all but 2 patients. One patient had persistent loss of left-sided activity, which resolved after transition to bilateral SACP. Another patient had persistent global loss of activity and was placed back on cardiopulmonary bypass for further cooling before reinitiation of CA. No significant differences in characteristics or outcomes were assessed between patients with and without loss of EEG activity.


CONCLUSIONS
Nearly half of patients undergoing hemiarch replacement with MHCA/SACP experience abrupt loss of electrocerebral activity after CA is initiated. Although unilateral SACP usually restores prearrest electrocerebral activity, intraoperative EEG may be particularly valuable for the identification of patients with persistent cerebral ischemia even after SACP.
Division of Cardiothoracic Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina.
Jeffrey E
JE
Keenan
Division of Cardiothoracic Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina.
Hanghang
H
Wang
Division of Cardiothoracic Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina.
Asvin M
AM
Ganapathi
Division of Cardiothoracic Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina.
Brian R
BR
Englum
Department of Neurology, Duke University Medical Center, Durham, North Carolina.
Emily
E
Kale
Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina.
Joseph P
JP
Mathew
Department of Neurology, Duke University Medical Center, Durham, North Carolina.
Aatif M
AM
Husain
Division of Cardiothoracic Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina. Electronic address: gchad.hughes@duke.edu.
G Chad
GC
Hughes
D000368:Aged; D000784:Aortic Dissection / Q000150:complications / Q000601:surgery*; D017545:Aortic Aneurysm, Thoracic / Q000150:complications / Q000601:surgery*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D050792:Circulatory Arrest, Deep Hypothermia Induced / Q000379:methods*; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D012189:Retrospective Studies; D020521:Stroke / Q000209:etiology / Q000517:prevention & control*; D014656:Vascular Surgical Procedures / Q000379:methods