The Changes of Cerebral Metabolic Parameters, Serum Levels of Neuron-Specific Enolase and S-100beta Protein During Retrograde Cerebral Perfusion Under Profound Hypothermic Total Circulatory Arrest

Kim, Kyung Hwan; Lee, Jae Ik

Abstract

BACKGROUND: Retrograde cerebral perfusion(RCP) is one of the methods used for brain protection during aortic arch surgery. The author previously published the data, however, for the safety of it, there still remains many controversies. The author performed RCP and checked various parameters to clarify the possibility of early detection of cerebral injury. MATERIAL AND METHOD: The author used pigs(Landrace species) weighing 25 to 30 kg and performed RCP for 120 minutes. After weaning of cardiopulmonary bypass, we observed pigs for another 120 minutes. Rectal temperature, jugular venous oxygen saturation, central venous pressure were continuously monitored, and the hemodynamic values, histological changes, and serum levels of neuron-specific enolose(NSE) and S100beta protein were checked. Central venous pressure during RCP was maintained in the range of 20 to 25 mmHg. RESULT: Flow rates(ml/min) during RCP were 224.3+/-87.5(20min), 227.1+/-111.0(40min), 221.4+/-119.5 (60min), 230.0+/-136.5(80min), 234.3+/-146.1(100min), and 184.3+/-50.0(120min). Serum levels of NSE did not increase after retrograde cerebral perfusion. Serum levels of S100beta protein(ng/ml) were 0.12+/-0.07(induction of anesthesia), 0.12+/-0.07(soon after CPB), 0.19+/-0.12(20min after CPB), 0.25+/-0.06(RCP 20min), 0.29+/-0.08(RCP 40min), 0.41+/-0.05(RCP 60min), 0.49+/-0.03(RCP 80min), 0.51+/-0.10(RCP 100 min), 0.46+/-0.11(RCP 120min), 0.52+/-0.15(30min after rewarming), 0.62+/-0.15(60min after rewarming, 0.76+/-0.17(CPBoff 30min), 0.81+/-0.20(CPBoff 60min), 0.84+/-0.23(CPBoff 90min) and 0.94+/-0.33(CPBoff 120min). The levels of S100beta after RCP were significantly higher than thosebefore RCP(p<0.05). The author could observe the mitochondrial swellings using transmission electron microscopy in neocortex, basal ganglia and hippocampus(CA1 region).
CONCLUSION
The author observed the increase of serum S100beta after 120 minutes of RCP. The correlation between its level and brain injury is still unclear. The results should be reevaluated with longterm survival model also considering the confounding factors like cardiopulmonary bypass.