Cerebral Protection in Aortic Arch Surgery

Aortic arch repair surgery is a technically complex and challenging procedure to treat aortic pathologies. Despite advancements in perioperative care, detrimental neurological complications occur during or after surgery. The neurological complications increase the economic burden of healthcare, morbidity and quality of life for the patients, even if they survive. Stroke, for example, leads to an increase in healthcare and social care costs, requiring a subsequent lengthy rehabilitation. Milder neurological impairments include transient ischaemic attacks, confusion and delirium, necessitating longer intensive care and hospital stay. Currently applied cerebral monitoring modalities are electroencephalogram and cerebral oximetry. However, they are not specific enough to timely detect early cerebral ischaemia to prevent neurological complications. S100B protein and neuron-specific enolase are serum markers that reflect cerebral damage, however, their applicability in the hyperacute setting is limited. However, rapid measurements of glial fibrillary protein have paved new pathways to detect cerebral injury. Recent studies reveal more sensitive biomarkers of glucose, lactate, pyruvate, glutamate and glycerol. These biomarkers could potentially detect cerebral ischaemia on a near real-time basis using the microdialysis method. The aim of the project is to develop a bedside system for early detection of cerebral ischaemia on a near real-time basis during aortic arch surgery. Early detection of cerebral ischaemia could mandate more aggressive cerebral protection strategies by further optimisation of hypothermia and antegrade selective cerebral perfusion during surgery, and optimisation of blood pressure and oxygenation in the intensive care unit. Ultimately, early detection of cerebral ischemia during surgery will prevent disabling and costly neurological complications following surgery.