ACP: Antegrade Selective Cerebral Perfusion, Sd: Standard Deviation, p^Ω: p value of lactate levels in Pre-ACP and during ACP, p^Ψ: p value of lactate levels in during ACP and Post-ACP, p^Σ: p value of lactate levels in Pre-ACP, postoperative 2th and 6th hour, p^α: Comparison of blood lactate values ​​taken from the descending aorta and radial artery during ACP