Effects of enteral immunonutrition in laparoscopic versus open resections in colorectal cancer surgery: A meta-analysis of randomised controlled trials.

Introduction: Immunonutrition (IMN) modulates the activity of the immune system. However, the effects of IMN on cancer patients following colorectal surgery is still lacking. We performed a systematic review and meta-analysis to evaluate the outcomes of IMN in patients undergoing laparoscopic versus open colorectal surgery.

Methods: A systematic search of multiple electronic data sources was conducted in accordance with PRISMA guidelines and included MEDLINE via PubMed, EMBASE, Scopus, and Web of Science. All eligible studies reporting comparative outcomes of immunonutrition in colorectal surgery were included. Subgroup analysis of outcomes of interest was performed and data were analysed using Review Manager (RevMan) Version 5.4.1.

Results: Nine randomised controlled trials (RCTs) were identified. The final pooled analysis included 1199 patients (592 IMN group and 592 control group). Of these, 55.3 % (655/1184) had open colorectal surgery (OG) and 44.7 % (529/1184) underwent laparoscopic colorectal surgery (LG). IMN reduced the risk of wound infection significantly in the OG [risk ratio (RR) 0.48, 95 % confidence interval (CI) 0.32 to 0.72; p = 0.0005)] and the open and laparoscopic group (OLG) [RR 0.33, 95 % CI 0.15 to 0.76; p = 0.008]. Moreover, IMN was also associated with a significantly shorter length of hospital stay (MD - 2.37 days, 95 % CI - 3.39 to -1.36; p < 0.0001) in the OG. Other post-operative morbidities (anastomotic leak and ileus) and mortality outcomes in the OG, LG, and OLG were comparable.

Conclusions: Pre-operative IMN could reduce the wound infection rate and shorten length of hospital stay in patients following elective colorectal surgery. The benefit of these improved clinical outcomes could be further evaluated with a cost-benefit analysis. IMN should be recommended as nutritional adjunct in the Enhanced Recovery after Surgery (ERAS) pathway following colorectal surgery.