Peri-operative immunonutrition in patients undergoing liver transplantation: a meta-analysis of randomized controlled trials

Background and Objectives: No consensus has been reached concerning the effects of pen-operative immunonutrition in patients undergoing liver transplantation. We conducted a meta-analysis to evaluate the effects of pen-operative immunonutrition on clinical outcomes and liver function in patients undergoing liver transplantation. Methods and Study Design: The Pubmed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and google scholar were searched to identify all available randomized controlled studies which compared pen-operative immunonutrition support (glutamine, omega-3 polyunsaturated fatty acids, arginine and ribonucleic acids) with standard nutrition. The data analysis was performed using Revman 5.2 software. Results: A total of 7 randomized controlled trials (RCTs) involving 501 patients were included. Pen-operative immunonutrition significantly reduced the risk of infectious complications (RR: 0.51; 95% CI: 0.27 to 0.98, p=0.04) and shortened the postoperative hospital stay [weighted mean difference (WMD): -3.89; 95% CI: -7.42 to -0.36; p=0.03]. Furthermore, pen-operative immunonutrition improved liver function by decreasing the levels of aspartate aminotransferase (AST) in the blood (WMD: -25.4; 95% CI: -39.9 to -10.9, p=0.0006). However, we did not find statistically significant differences in serum alanine aminotransferase (ALT), total bilirubin (TB) and direct bilirubin (DB) levels. There were no statistically significant differences in mortality and rejection reaction. Conclusions: Pen-operative nutrition support adding immunonutrients like glutamine, omega-3 polyunsaturated fatty acids, arginine and ribonucleic acids may improve outcomes in patients undergoing liver transplantation. Due to the limited sample size of the included trials, further large-scale and rigorously designed RCTs are needed.