Clinical Efficacy of Perioperative Immunonutrition Containing Omega-3-Fatty Acids in Patients Undergoing Hepatectomy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

<b><i>Background:</i></b> The effect of immunonutrition in patients undergoing hepatectomy remains unclear. This meta-analysis aimed to assess the impact of immunonutrition on postoperative clinical outcomes in patients undergoing hepatectomy. <b><i>Methods:</i></b> A literature search of PubMed, Cochrane Library, Web of Science, and Embase databases was performed to identify all randomized controlled trials (RCTs) exploring the effect of perioperative immunonutrition in patients undergoing hepatectomy until the end of March 10, 2020. Quality assessment and data extraction of RCTs were conducted independently by 3 reviewers. Mean difference (MD) and odds ratio (OR) with 95% confidence interval (CI) were calculated using a fixed-effects or random-effects model. The meta-analysis was performed with RevMan 5.3 software. <b><i>Results:</i></b> Nine RCTs involving a total of 966 patients were finally included. This meta-analysis showed that immunonutrition significantly reduced the incidences of overall postoperative complications (OR = 0.57, 95% CI: 0.34–0.95; <i>p</i> = 0.03), overall postoperative infectious complications (OR = 0.53, 95% CI: 0.37–0.75; <i>p</i> = 0.0003), and incision infection (OR = 0.50, 95% CI: 0.28–0.89; <i>p</i> = 0.02), and it shortened the length of hospital stay (MD = −3.80, 95% CI: −6.59 to −1.02; <i>p</i> = 0.007). There were no significant differences in the incidences of pulmonary infection (OR = 0.60, 95% CI: 0.32–1.12; <i>p</i> = 0.11), urinary tract infection (OR = 1.30, 95% CI: 0.55–3.08; <i>p</i> = 0.55), liver failure (OR = 0.54, 95% CI: 0.23–1.24; <i>p</i> = 0.15), and postoperative mortality (OR = 0.69, 95% CI: 0.26–1.83; <i>p</i> = 0.46). <b><i>Conclusion:</i></b> Given its positive impact on postoperative complications and the tendency to shorten the length of hospital stay, perioperative immunonutrition should be encouraged in patients undergoing hepatectomy.