Use of N-acetyl-cysteine in the Perioperative Period of Liver Transplantation: A Scoping Review

ABSTRACT

Objective:

To find evidence on the use of N-acetyl-cysteine (NAC) in the perioperative period of liver transplantation, since NAC, as it is the acetylated precursor of L-cysteine and reduced glutathione, contributes to the hepatic supply of glutathione, helping the liver to recover from ischemia and reperfusion injury.

Methodology:

This is a scoping review of the PubMed, VHL and Web of Science databases. The descriptors “Liver transplantation”, “N-acetyl-cysteine” and “Reperfusion Ischemia” were used, with the Boolean operator “AND”, and articles relevant to the topic were selected. Initially, 60 articles were selected, all published in the last 24 years, in Portuguese and/or English. After analysis, eight articles corresponded to the proposed objective.

Results:

The groups that received NAC during TxF showed post-reperfusion hypotension, lower intraoperative pH values, higher plasma concentrations of IL-4 and a significant increase in IL-10 levels five minutes before reperfusion. Inhibition of α-glutathione S-transferase (α-GST) was also observed after reperfusion, unlike the control group, which showed a significant increase in this enzyme. Furthermore, sVCAM-1 and sICAM-1 levels were significantly lower in the NAC group 24 hours after reperfusion compared with the placebo group. The maximum AST value during the first 72 postoperative hours was similar in both groups, although the peak ALT was lower in the NAC group than in the placebo group. In grafts that received NAC in the perfusion solution, survival rates at 3 and 12 months were 93% and 90%, respectively, and in the control group were 82% and 70%, respectively. The incidence of postoperative complications was 23% in the NAC group and 51% in the control group. The incidence of EPD was lower for the NAC group, which was 15% versus 32% in the control group. Regarding the administration of NAC during the intraoperative TxF, the one-year patient survival rate was 78.4% in the NAC group compared to 80.9% in the placebo group.

Conclusion:

Intraoperative administration of NAC during the anhepatic phase was associated with a protective effect against reperfusion injury, however in other studies limitations were observed in protection against liver injury, in biomarkers of oxidative stress, in inflammation and in the functioning of liver enzymes.

Descriptors
N-acetyl-cysteine; Liver Transplant; Reperfusion Ischemia