Experimental Study of Cerebral Protection in Piglets During Deep Hypothermic Circulatory Arrest

OBJECTIVE To study cerebral protection during deep hypothermic circulatory arrest, using deep hypothermic circulatory arrest (DHCA), retrograde cerebral perfusion (RCP) and selective cerebral perfusion (SCP).METHODS Fifteen piglets were divided into three groups DHCA group, RCP group and SCP group randomly. Piglets were cooled to 18℃, underwent DHCA for 90 min and reperfusion for 90 min. At the different points of experiment, artery and vein blood gas were analyzed, oxygen metabolism and water content were measured. RESULTS Parameters showed that Pvo 2,Pvco 2 and oxygen extraction rate (OER) levels of DHCA group reached statistics significance between RCP group and SCP group after hypothermic circulatory arrest 30 min(P0.05). RCP group had significant lower tissue oxygen metabolic levels compared to SCP after DHCA 60 min (P0.05). Brain edema was present in both DHCA group and RCP group.CONCLUSION In piglet's model, DHCA method is simple, but safe period is very short. RCP prolong safe period in DHCA, but safe period of RCP is limitted to 60 min. SCP is not limited by operative time. SCP is the best method for cerebral protection to provides physiological cerebral blood flow and better cerebral oxygenation.