Graft dysfunction following liver transplantation: role of free radicals

Background/Aims: Following orthotopic liver transplantation primary graft non-function occurs in about 10% of patients, and survival depends on early retransplantation. The aetiology has yet to be defined, but reperfusion injury as a result of free radical production has been considered as a possible mechanism. In this study we looked for evidence of free radical generation intraoperatively and assessed the relationship between free radical production and graft function. Methods/Results: Twenty-one patients (M:F 10:11, mean age; 53±3.8 years) who underwent liver transplantation for end-stage liver disease were studied. Free radical activity increased significantly following reperfusion, as shown by: (i) the diene conjugated method, where the percentage molar ratio increased from a baseline of 10.87±0.78% to 24.42±7.8% (p<0.01), and (ii) by electron paramagnetic resonance, where a more than a twofold rise in radical concentration was detected (p<0.05). The increase in free radical activity detected by the diene conjugated method was significantly higher in patients with poor outcome as compared with those who had uneventful recovery (p<0.01). Conclusion: Free radical activity is increased following reperfusion of liver graft during transplantation, and the magnitude of the rise is related to the severity of graft dysfunction.