Significance of Bioelectrical Impedance during Ischemia-Reperfusion Injury in the Rabbit's Liver

ABSTRACT

PURPOSE: During liver resection and transplantation, liver is damaged by ischemia-reperfusion injury. Until now, there is no approved method to measure or predict the extent of liver injury during the operation. This is the preliminary study to make the real time monitoring system by quantification of bioelectrical impedance and ischemia-reperfusion injury in liver. METHODS: Male Newzealand white rabbits(body weight 3.5-4.0 kg) were used. We observed changes of bioelectrical impedance during ischemia and reperfusion injury according to frequency(120 Hz-100 KHz). Bioelectrical impedance of liver tissue were measured every 5 minutes interval with two mono-polar needle coated with platinum using LCR meter (GS-4311B, ANDO, Japan). Cell viability was assessed by metabolic capacity of fatty acid (palmitic acid metabolic rate) and histologic examination (H&E stain) at every 30 minutes interval during 120 minutes ischemia. RESULTS: Liver bioelectrical impedance was changed significantly(p<0.05) during ischemia in lower frequency compared to those of higher frequency. Bioelectrical impedance(120 Hz) increased during ischemia and returned to base line level after reperfusion. The level of bioelectrical impedance(120 Hz) increased gradually after ischemia for 1 hour. After 1 hour, the level of bioelectrical impedance had tendency to maintain plateau. Palmitic acid oxidation rate were not changed significantly during 120 minutes ischemia and there were no significant difference in histologic examination. CONCLUSION: We found the possible role of bioelectrical impedance to measure and predict the extent of ischemia-reperfusion injury.