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.引言：机器人胃切除术具备围手术期优势，如减少失血量、加快术后恢复，但感染性并发症仍是亟待关注的重要问题。本研究旨在明确胃或食管胃结合部癌患者行根治性机器人胃切除术后发生术后感染性并发症的预测因素。 方法：本研究为单中心回顾性研究，纳入2017年12月至2025年4月期间接受根治性机器人胃切除术的155例胃或食管胃结合部癌患者的临床数据，旨在探讨术后感染性并发症的预测因素。研究共评估了包括营养指标、手术相关因素在内的22项变量。 结果：共计18例患者发生克拉恩-丁多分级（Clavien–Dindo）Ⅱ~Ⅲa级感染性并发症。具体并发症类型包括肺炎（n=5，3.2%）、腹腔脓肿（n=5，3.2%）、吻合口漏（n=3，1.9%）、胆囊炎（n=2，1.2%）、非闭塞性肠系膜缺血（n=1，0.6%）、胆漏（n=1，0.6%）及脓毒症（n=1，0.6%）。与未发生并发症的患者相比，并发症组美国麻醉医师协会身体状况分级（American Society of Anesthesiologists Physical Status, ASA-PS）≥3级的患者占比（p=0.006）及术前有吸烟史的患者占比（p=0.012）均更高。并发症组患者的血红蛋白水平（p=0.041）及淋巴细胞/单核细胞比值（lymphocyte-to-monocyte ratios, LMR，p=0.017）更低，而血小板/淋巴细胞比值（p=0.034）更高。多因素分析显示，当前吸烟（优势比=3.21，95%置信区间：1.24~18.21）与ASA-PS分级≥3级（优势比=3.8，95%置信区间：1.18~7.52）为术后感染性并发症的独立预测因素。 结论：机器人胃切除术具备技术优势，但针对患者个体优化风险防控是获得最佳预后的关键。术前吸烟与高ASA-PS分级是机器人胃切除术后感染性并发症的独立预测因素。针对上述风险因素强化围手术期管理，可降低术后并发症发生率。