Impact of preoperative immunonutrition on postoperative outcomes in gastrointestinal cancer surgery: a systematic review and meta-analysis

Impact of preoperative immunonutrition in gastrointestinal cancer surgery

Abstract

Background:
Patients with gastrointestinal cancer are at significant risk of malnutrition. Notably, the condition of most patients is often more deteriorated postoperative. Infections, poorer recovery and longer hospital stays are common complications of malnutrition. While preoperative immunenutrition emerged as an intervention tended to improve postoperative outcomes, the current evidence is limited. This review aims to investigate the effect of preoperative immunonutrition on postoperative complications and recovery in patients undergoing gastrointestinal cancer surgery.
Methods:
A comprehensive literature search was performed using MEDLINE, EMBASE (via Ovid), Google Scholar, ClinicalTrials.gov., and the Cochrane Central Register of Controlled Trials (CENTRAL). Randomized controlled trials and observational studies were included. The ROB II tool and Minors’ checklist were used to assess the risk of bias of the included studies. While the treatment effect for dichotomous outcomes was expressed as a pooled odds' ratio (OR) with a 95% CI, continuous outcomes were pooled using the standardized mean difference (Hedges' *g*) with a 95% CI.
Results:
A total of 2,536 participants from the 19 included studies met the inclusion criteria. Preoperative immunonutrition revealed a protective effect against postoperative complications in patients undergoing gastrointestinal cancer surgery (Pooled OR = 0.57, 95% CI 0.39–0.82, p = 0.001). Similarly, infectious complications were significantly reduced after preoperative immunonutrition (OR = 0.48, 95% CI 0.34–0.68, p = 0.00). In contrast, no statistically significant overall effect was found on postoperative length of hospital stay (LOS) (Pooled Hedges' g = 0.37, 95% CI -0.59 to 1.34, p = 0.45).
Conclusion:
Preoperative immunonutrition is a promising intervention in patients undergoing gastrointestinal cancer surgery. This strategy decreases infectious complications and improves postoperative response. Future research should investigate their pathways and integrate the intervention into the multimodal perioperative care guidelines. Recent randomized controlled trials — especially on high-risk malnourished patients — are required to determine the appropriate timing, and formulations and patient selection.