Abstract / Summary
High body mass index (BMI) and CT-defined visceral adiposity may increase the technical difficulty of minimally invasive gastrectomy for gastric cancer. Whether robotic gastrectomy offers a comparative advantage over laparoscopic gastrectomy in these adiposity-defined populations is uncertain. PubMed/MEDLINE, Scopus, and the Cochrane Library were searched from inception to 29 August 2026 using prespecified strategies; reference lists were also checked. English-language comparative studies of robotic versus laparoscopic gastrectomy for gastric malignancy were eligible when overweight, obesity, or high visceral adiposity was defined categorically and arm-level data were extractable. Two reviewers independently performed screening, extraction, ROBINS-I assessment, and conventional GRADE assessment. Overlapping cohorts were resolved outcome by outcome. Random-effects models used restricted maximum likelihood with modified Hartung-Knapp confidence intervals. Primary outcomes were overall postoperative complications, major postoperative complications, operative time, and estimated blood loss. In total, 16 studies were eligible, all from South Korea, China, or Japan. Overall complications did not differ significantly between robotic and laparoscopic gastrectomy (10 studies; 1,695 participants; RR 0.81, 95% CI 0.60 to 1.10; P = 0.153; I²=0%). Major complications yielded an RR of 0.56 (8 studies; 1,858 participants; 95% CI 0.20 to 1.52; P = 0.210; I²=53%). The pooled mean difference in operative time was + 31.13 min (7 studies; 1,037 participants; 95% CI - 9.60 to + 71.86; P = 0.111; I²=92%), while the mean difference in estimated blood loss was - 10.27 mL (6 studies; 939 participants; 95% CI - 38.20 to + 17.66; P = 0.388; I²=74%). The certainty of evidence was very low for all primary outcomes. In East Asian patients with overweight, obesity, or high visceral adiposity undergoing gastrectomy for gastric cancer, very-low-certainty evidence did not establish a clear difference between robotic and laparoscopic surgery for any primary outcome. Applicability to Western patients remains uncertain. Future prospective multicenter studies, including Western populations and using standardized adiposity definitions and patient-centered outcomes, are needed to clarify the comparative value of robotic and laparoscopic gastrectomy.