The effects of enteral immunonutrition in upper gastrointestinal surgery: A systematic review and meta-analysis

AIM: The beneficial of immunonutrition on overall morbidity and mortality remains uncertain. We undertook a systematic review to evaluate the effects of immune-enhancing enteral nutrition (IEN) in upper gastrointestinal (GI) surgery.

METHODS: Main electronic databases [MEDLINE via Pubmed, EMBASE, Scopus, Web of Knowledge, Cochrane Central Register of Controlled Trials (CENTRAL) and the Cochrane Library, and clinical trial registry (ClinicalTrial.gov)] were searched for studies reported clinical outcomes comparing standard enteral nutrition (SEN) and immunonutrition (IEN). The systematic review was conducted in accordance with the PRISMA guidelines and meta-analysis was analysed using fixed and random-effects models.

RESULTS: Nineteen RCTs with a total of 2016 patients (1017 IEN and 999 SEN) were included in the final pooled analysis. The ratio of patients underwent oesophagectomy:gastrectomy:pancreatectomy was 2.2:1.2:1.0. IEN, when administered post-operatively, was associated with a significantly lower risk of wound infection (risk ratio (RR) 0.59, 95% confidence interval (CI) 0.40 to 0.88; p = 0.009) and shorter length of hospital stay (MD -2.92 days, 95% CI -3.89 to -1.95; p < 0.00001). No significant differences in other post-operative morbidities of interest (e.g. anastomotic leak and pulmonary infection) and mortality between the two groups were identified.

CONCLUSIONS: Overall, our analysis found that IEN decreases wound infection rates and reduces length of stay. It should be recommended as routine nutritional support as part of the Enhanced Recovery after Surgery (ERAS) programmes for upper GI Surgery.