The use of preoperative enteral immunonutrition in patients undergoing elective colorectal cancer surgery: A systematic review and meta-analysis.

AIM: The present systematic review and meta-analysis aims to compare adult patients receiving enteral immunonutrition prior to elective colorectal surgery with those receiving conventional preoperative nutrition.

METHODS

MEDLINE, Embase and the Cochrane Central Register of Controlled Trials were searched from database inception to March 2024. Articles were included if they were randomized controlled trials or cohort studies evaluating adult patients undergoing elective colorectal surgery comparing preoperative enteral immunonutrition with conventional preoperative nutrition protocols. Main outcomes of interest included surgical site infection, anastomotic leak, overall postoperative morbidity and postoperative length of stay. An inverse variance random effects meta-analysis was performed. Risk of bias was assessed with Cochrane risk of bias assessment tools. The GRADE approach was conducted to assess quality of evidence.

RESULTS

After reviewing 2508 relevant citations, 10 studies met inclusion criteria. Overall, 1521 patients (mean age 64.9 ± 10.0 years, 49.4% women) received preoperative immunonutrition and 1816 patients (mean age 64.1 ± 11.0 years, 52.1% women) received conventional preoperative nutrition. Across seven studies, there was a non-significant 30% relative risk reduction of surgical site infection (risk ratio 0.70, 95% CI 0.44-1.11, P = 0.13, I2 = 33%) and a non-significant 44% relative risk reduction of anastomotic leak (risk ratio 0.56, 95% CI 0.28-1.10, P = 0.09, I2 = 0%) in the immunonutrition group. Across eight studies, postoperative length of stay was 0.48 days shorter in the immunonutrition group (mean difference -0.48, 95% CI -0.84 to -0.12, P = 0.01, I2 = 53%). GRADE certainty of evidence was low or very low for all outcomes.

CONCLUSION

While point estimates suggest a likely benefit associated with preoperative enteral immunonutrition, wide corresponding 95% CIs suggest uncertainty remains. Further prospective study is warranted.