Supplementary Material for: Predictive Factors for Infectious Complications After Robotic Gastrectomy for Gastric or Esophagogastric Junction Cancer

Introduction: Robotic gastrectomy offers perioperative advantages such as reduced blood loss and faster recovery; however, infectious complications remain a significant concern. In this study, we aimed to identify the predictive factors for postoperative infectious complications following radical robotic gastrectomy in patients with gastric or esophagogastric junctional cancer. Methods: This retrospective single-center study analysed data from 155 patients with gastric or esophagogastric junction cancer who underwent curative robotic gastrectomy between December 2017 and April 2025 to identify predictive factors for postoperative infectious complications. Twenty-two variables, including nutritional indices and surgical factors, were evaluated. Results: A total of 18 patients developed Clavien–Dindo grade II–IIIa infectious complications. Infectious complications included pneumonia (n=5, 3.2%), intra-abdominal abscess (n=5, 3.2%), anastomotic leakage (n=3, 1.9%), cholecystitis (n=2, 1.2%), nonocclusive mesenteric ischemia (n=1, 0.6%), bile leakage (n=1, 0.6%), and sepsis (n=1, 0.6%). The number of patients with complications and American Society of Anesthesiologists Physical Status (ASA-PS) class ≥3 (p=0.006) and preoperative smoking (p=0.012) was higher than that among patients without complications. Although hemoglobin levels (p=0.041) and lymphocyte-to-monocyte ratios (LMR, p=0.017) were lower in patients with complications, the platelet-to-lymphocyte ratios (p=0.034) were higher. Multivariate analysis revealed that current smoking (odds ratio, 3.21; 95% confidence interval, 1.24–18.21) and ASA-PS class of ≥3 (odds ratio, 3.8; 95% confidence interval, 1.18–7.52) were identified as predictors of infectious complications. Conclusion: Robotic gastrectomy offers technical advantages, but optimizing patient-specific risk is essential for the best outcomes. Preoperative smoking and a high ASA-PS class were independent predictors of infectious complications following robotic gastrectomy. Enhanced perioperative management targeting these risk factors may reduce postoperative morbidity.