Intraoperative detection and management of cerebral malperfusion in acute aortic dissection using regional cerebral oxygen saturation monitoring: case report

Background Cerebral malperfusion during acute aortic dissection (AAD) surgery is a life-threatening event requiring prompt detection and intervention. We report a case of intraoperative extension of dissection into the brachiocephalic artery (BCA) detected by regional cerebral oxygen saturation (rSO₂) monitoring before cardiopulmonary bypass. Case presentation A 78-year-old man undergoing emergency total aortic arch replacement showed a sudden bilateral rSO₂ decline after anesthesia induction, corresponding to BCA extension on transesophageal echocardiography. rSO₂ recovered during selective cerebral perfusion but fell again during CPB weaning. Carotid duplex ultrasonography revealed collapse of the right common carotid artery due to false lumen expansion compressing the true lumen. Reanastomosis of the BCA restored cerebral oxygenation. Conclusion This case highlights the utility of multimodal monitoring—rSO₂ trends, transesophageal echocardiography, and carotid duplex ultrasonography—for detecting and managing cerebral malperfusion during AAD surgery. Early identification allows timely surgical revision and may improve neurological outcomes.