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