Neuroprotection and classification of neurologic dysfunction in aortic arch surgery: A narrative review

Abstract

Open aortic arch surgery incurs frequent neurologic complications and high mortality. The disease processes of aortic aneurysm and acute aortic dissection, and the physiological trespass of cardiopulmonary bypass and hypothermic circulatory arrest (CA), can engender neurologic dysfunction such as postoperative stroke and delirium. While deep hypothermic CA (with and without retrograde cerebral perfusion) is the major strategy for brain protection, moderate hypothermic CA with antegrade cerebral perfusion has comparable or better outcomes. Classes of neurologic complications in aortic arch surgery were defined three decades ago. In 2021, the Valve Academic Research Consortium recommended new endpoints for assessing neurologic outcomes of transcatheter and surgical aortic valve procedures. Those parameters include neuroimaging biomarkers. Overt central nervous system (CNS) injury is the severe form and delirium is the common clinical presentation. Covert CNS injury, evidenced on brain imaging, is prevalent in patients following transcatheter aortic valve replacement (TAVR). The new definition for neurologic dysfunction after TAVR could serve in the classification of neurologic dysfunction in aortic arch surgery.

Keywords

• aortic arch surgery
• deep hypothermic circulatory arrest
• neuroprotection
• retrograde cerebral protection
• antegrade cerebral protection
• central nervous system injury