Abstract: We included six trials involving 418 patients for this review. The sample size in the trials varied from 30 to 131 patients. Only one trial involving 131 patients was of low risk of bias for mortality. This trial was at high risk of bias for other outcomes. Four trials excluded patients who underwent liver transplantation for acute liver failure. All the trials included livers obtained from cadaveric donors. The remaining five trials were of high risk of bias for all outcomes. Liver transplantation was performed by the conventional method (caval replacement) in two trials and piggy-back method (caval preservation) in one trial. The method of liver transplantation was not available in the remaining three trials. The comparisons performed included an initial hepatic artery flush versus initial portal vein flush; blood venting via inferior vena cava in addition to venting of storage fluid versus no blood venting; initial hepatic artery reperfusion versus initial portal vein reperfusion; simultaneous hepatic artery and portal vein reperfusion versus initial portal vein reperfusion; and retrograde inferior vena cava reperfusion versus simultaneous hepatic artery and portal vein reperfusion. Only one or two trials could be included under each comparison. There was no significant difference in mortality, graft survival, or severe morbidity rates in any of the comparisons. Quality of life was not reported in any of the trials. There is currently no evidence to support or refute the use of any specific technique of flushing or reperfusion during liver transplantation. Due to the paucity of data, absence of evidence should not be confused with evidence of absence of any differences. Further well designed trials with low risk of systematic error and low risk of random errors are necessary.

Plain-language summary: We included six trials involving 418 patients for this review. The number of patients included in the trials varied from 30 to 131. Most of the trials were at high risk of systematic errors (ie, there was a potential to arrive at wrong conclusions because of the way the trial was conducted) and random errors (there was a potential to arrive at the wrong conclusions because of the play of chance). The comparisons performed included initial hepatic artery flush versus initial portal vein flush; blood venting via the inferior vena cava in addition to venting of storage fluid versus no blood venting; initial hepatic artery reperfusion versus initial portal vein reperfusion; simultaneous hepatic artery and portal vein reperfusion versus initial portal vein reperfusion; and retrograde inferior vena cava reperfusion versus simultaneous hepatic artery and portal vein reperfusion. There were no significant differences in the risk of death or graft loss, or in the major complication rates, between the compared groups in any of the comparisons. Quality of life was not reported in any of the trials. There were no significant differences in the transfusion requirements, intensive therapy unit stay, or hospital stay between the compared groups in any of the comparisons. We are unable to advocate or refute any technique of flushing and reperfusion in patients undergoing liver transplantation. Further well designed trials with low risk of systematic error and low risk of random errors are necessary.