Effect of Perioperative Supplementation with Arginine and Omega-3 on Postoperative Complications in Patients Undergoing Gastrointestinal Cancer Surgery: A Pilot Open-Label Randomized Controlled Trial

Background: Perioperative immunonutrition, including arginine and omega-3 fatty acids, has been proposed to support postoperative recovery by modulating immune function. Aim: To evaluate the effects of perioperative arginine and omega-3 supplementation on postoperative infectious complications, mortality, hospital length of stay, intensive care unit duration, and inflammatory markers in patients undergoing gastrointestinal cancer surgery. Methods: In this Pilot Open-Label randomized trial, 35 adult patients scheduled for elective gastrointestinal cancer surgery at Salah Azaiez Institute were randomly assigned to receive either perioperative immunonutrition (n = 18; three daily capsules of omega-3 and one sachet of Arginine+ for 7 days preoperatively and 7 days postoperatively) or standard care (n = 17). Primary endpoints were postoperative infectious complications and 1-month mortality. Secondary endpoints included hospital length of stay, ICU duration, and postoperative biochemical markers. Results: No statistically significant differences were observed between groups in 1-month mortality (p = 0.324), hospital length of stay (median 7 vs. 7 days, p = 0.392), or ICU duration (median 5 vs. 6 days, p = 0.601). Urinary tract infection (5.9% vs. 11.1%, p = 0.939) and wound infection rates (5.9% vs. 11.1%, p = 0.581) were comparable. Importantly, postoperative C-reactive protein and other inflammatory markers did not differ significantly between groups (CRP: 165 vs. 175 mg/L; intergroup p = 0.798). Conclusions: In this trial, perioperative immunonutrition with arginine and omega-3 fatty acids did not improve postoperative clinical outcomes or inflammatory markers in patients undergoing gastrointestinal cancer surgery. At the administered dose and within a small, heterogeneous cohort, immunonutrition did not provide additional benefit beyond standard care. Larger, adequately powered multicenter trials with optimized dosing are required to clarify its role in gastrointestinal oncology.