title: Neurophysiological Intraoperative Monitoring During Aortic Arch Surgery.
abstract: Circulatory management during replacement of the aortic arch is complex and involves a period of circulatory arrest to provide a bloodless field during arch vessel anastomosis. To guard against ischemic brain injury, tissue metabolic demand is reduced by systemically cooling the patient prior to circulatory arrest. Neurophysiological intraoperative monitoring (NIOM) is often used during the course of these procedures to provide contemporaneous assessment of brain status to help direct circulatory management decisions and detect brain ischemia. In this review, we discuss the characteristics of electrocerebral activity through the process of cooling, circulatory arrest, and rewarming as depicted through commonly used NIOM modalities, including electroencephalography and peripheral nerve somatosensory-evoked potentials. Attention is directed toward the role NIOM has traditionally played during deep hypothermic circulatory arrest, where it is used to define the point of electrocerebral inactivity or maximal cerebral metabolic suppression prior to initiating circulatory arrest while also discussing the evolving utility of NIOM when systemic circulatory arrest is initiated at more moderate degrees of hypothermia in conjunction with regional brain perfusion. The use of cerebral tissue oximetry by near-infrared spectroscopy as an alternative NIOM modality during surgery of the aortic arch is addressed as well. Finally, special considerations for NIOM and the detection of spinal cord ischemia during hybrid aortic arch repair and emerging operative techniques are also discussed.
authors.affiliation: Division of Cardiovascular and Thoracic Surgery, Department of Surgery, Duke University Medical Center, Durham, NC, USA.
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Keenan
authors.affiliation: Division of Cardiovascular and Thoracic Surgery, Department of Surgery, Duke University Medical Center, Durham, NC, USA.
authors.forename: Ehsan
authors.initials: E
authors.lastname: Benrashid
authors.affiliation: Department of Neurology, Duke University Medical Center, Durham, NC, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Kale
authors.affiliation: Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA.
authors.forename: Alina
authors.initials: A
authors.lastname: Nicoara
authors.affiliation: Department of Neurology, Duke University Medical Center, Durham, NC, USA.
authors.forename: Aatif M
authors.initials: AM
authors.lastname: Husain
authors.affiliation: Division of Cardiovascular and Thoracic Surgery, Department of Surgery, Duke University Medical Center, Durham, NC, USA gchad.hughes@duke.edu.
authors.forename: G Chad
authors.initials: GC
authors.lastname: Hughes
mesh_terms: D001013:Aorta, Thoracic / Q000601:surgery*; D050792:Circulatory Arrest, Deep Hypothermia Induced; D004569:Electroencephalography; D057510:Endovascular Procedures; D005073:Evoked Potentials, Somatosensory; D006801:Humans; D016343:Monitoring, Intraoperative; D019265:Spectroscopy, Near-Infrared
keywords: brain oximetry; cardiac anesthesia; cardiac surgery; circulatory arrest; deep hypothermic circulatory arrest; electroencephalography; hypothermia; near-infrared spectroscopy; neurological monitoring; neuroprotection