Preoperative immunonutrition significantly reduced surgical site infection after urinary diversion for invasive bladder cancer: a retrospective cohort study

Background Radical cystectomy and ileal conduit have a high incidence of surgical site infection. In this study, we evaluated the effects of preoperative immunonutrition on its incidence following these procedures. Methods We retrospectively enrolled 86 patients who underwent radical cystectomy and ileal conduit at our hospital between 2014 October and 2021 July. They were sequentially divided into the Immunonutrition group (n=43) and Control group (n=43). Patients in the Immunonutrition group drank 4 packs of IMPACT (Nestle, Japan) per day for 5 days before surgery. IMPACT contains arginine and eicosapentaenoic acid. We compared levels of plasma arginine and eicosapentaenoic acid before and after surgery and the rate of surgical site infection between the groups. Factors related to surgical site infection were analyzed using univariate and multivariable logistic regression analysis. Results No statistically significant differences were observed in patient characteristics between the groups except for surgical operative method (p<0.001) and transfusion (p=0.009). Levels of plasma arginine and eicosapentaenoic acid were significantly increased the day before surgery in the immunonutrition group (p<0.001). However, the levels of plasma arginine on the day after surgery did not vary significantly between the groups. The incidence of surgical site infection was significantly lower in the immunonutrition group (p=0.014). Multivariate analyses showed a significant association of surgical site infection with immunonutrition (OR=0.14, CI 0.03–0.72, p=0.019) and with ASA classification (OR=4.76, CI 1.23–18.40, p=0.024). Conclusions Preoperative immunonutrition significantly reduced the incidence of surgical site infection following radical cystectomy and ileal conduit.