The Effect of immunonutrition in patients undergoing pancreaticoduodenectomy: a systematic review and meta-analysis

Pancreaticoduodenectomy (PD) is a complex and traumatic abdominal surgery with a high risk of postoperative complications. Nutritional support, including immunonutrition (IMN) with added glutamine, arginine, and ω-3 polyunsaturated fatty acids, can improve patients' prognosis by regulating postoperative inflammatory response. However, the effects of IMN on PD patients' outcomes require further investigation. PMC, EMbase, web of science databases were used to search literatures related to IMN and PD. Data such as length of hospital stay, infectious complications, non-infectious complications, postoperative pancreatic fistula (POPF), delayed gastric emptying (DGE), mortality, systemic inflammatory response syndrome (SIRS) duration, IL-6, and C-reactive protein (CRP) were extracted, and meta-analyses were performed on these data to study their pooled results, heterogeneity, and publication bias. This meta-analysis involved 10 studies and a total of 572 patients. The results showed that the use of IMN significantly reduced the length of hospital stay for PD patients (MD = -2.31; 95% CI = -4.43, -0.18; P = 0.03) with low heterogeneity. Additionally, the incidence of infectious complications was significantly reduced (MD = 0.42; 95% CI = 0.18, 1.00, P = 0.05), with low heterogeneity after excluding one study. However, there was no significant impact on non-infectious complications, the incidence of POPF and DGE, mortality rates, duration of SIRS, levels of IL-6 and CRP. The use of IMN has been shown to significantly shorten hospital stays and decrease the frequency of infectious complications in PD patients. Early implementation of IMN is recommended for those undergoing PD. However, further research is needed to fully assess the impact of IMN on PD patients through larger and higher-quality studies.