The Influence of Resuscitation on Hemodynamics and Oxygen Radical-Induced Reperfusion Injury after Arterialized Liver Transplantation in the Rat

Extended hemodynamic monitoring during arterialized rat liver transplantation procedure and the effects of resuscitation with albumin, starch-desferrioxamine-conjugated hydroxyethyl starch (HES-DFO), or hydroxyethyl starch (HES) on hemodynamics are presented. Livers from SPRD rats were stored for 20 hr in ice-cold UW solution and were orthotopically transplanted with reconstruction of the hepatic artery under hemodynamical monitoring applying invasive measurement of mean arterial blood pressure (MAP) and cardiac output (CO). Comparable amounts of albumin, HES-DFO, and HES were given in a randomized and blinded fashion after transplantation. Ringer's solution was given additionally when blood pressure was below 65 mmHg. Fifteen, 60, and 90 min after surgical procedure blood samples were taken to determine acid base status, blood gases, and blood cell count. Oxygen radical-induced reperfusion injury was determined by thiobarbituric acid reactive substances (TBARS) in serum and total glutathione in liver tissue 90 min after surgery. During the anhepatic period CO was reduced to 20% of baseline and MAP to 40 mmHg. In all groups, declamping led to a transient recovery of hemodynamic situation, whereas during further reperfusion, CO and MAP were significantly reduced in the HES- and HES-DFO-treated group in contrast to the group receiving albumin. Animals of the HES group required significantly more Ringer's solution to maintain blood pressure (2.6 ± 0.9 ml; 4 of 6 animals needed additional resuscitation) than animals given albumin (0.4 ± 0.3 ml,P< 0.05, 2/9 needed further supplementation) or HES-DFO (1.2 ± 0.5 ml; 5/10 required additional resuscitation), respectively. Animals treated with HES or HES-DFO failed to restore base excess and serum lactate in contrast to resuscitation with albumin. However, TBARS was mitigated by resuscitation with HES-DFO compared to albumin and HES, whereas no significant differences were observed in respect to tissue glutathione of transplanted livers. In conclusion the model described allows intensive monitoring of hemodynamic parameters and metabolic status during arterialized rat liver transplantation procedure. Moreover, the results indicate that resuscitation with albumin could maintain central hemodynamics and restore homeostasis during the early reperfusion period after transplantation in contrast to resuscitation with HES or HES-DFO, respectively. Although resuscitation with HES-DFO resulted in mitigation of lipid peroxides determined by TBARS, no significant improvement of hemodynamics and homeostasis could be observed during reperfusion as it can be observed with albumin.