Peripheral serum samples will be drawn before induction, before cross-clamping the carotid artery, 15 minutes after cross-clamping the carotid artery and 24 hours after surgery. These samples will be analyzed for four different sets of markers of cerebral injury, one gene and two markers of systemic inflammation. Serum levels of neuron specific enolase (NSE) and protein S100B, a neuronal enzyme and glial cell component respectively, markers of cell injury will demonstrate cerebral injury