The effect of excess body weight on short-term outcomes following minimally invasive rectal cancer surgery: a systematic review and meta-analysis

BACKGROUND: The converging trends of a global increase in the incidence of colorectal cancer (CRC) and the prevalence of obesity suggest that surgery for CRC in patients with excess body weight (EBW) will become an increasingly common clinical entity. We aimed to evaluate the effect of EBW, defined as being overweight or obese, on short-term perioperative outcomes following minimally invasive rectal cancer surgery (MIRCS). MATERIALS AND METHODS: The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, EMBASE, Web of Science, and the Cochrane Library were searched for relevant studies. Only comparative studies comparing MIRCS in patients with vs without EBW were included. Studies evaluating open rectal cancer surgery were excluded. This review was prospectively registered on PROSPERO (CRD42024591252). RESULTS: Twenty-six retrospective cohort studies involving 7172 patients were analysed. Patients with EBW had greater rates of open conversion (risk ratio (RR) 1.64, 95% CI 1.19-2.26), longer operative durations (mean difference (MD) 20.81 min, 95% CI 13.31-28.30), increased postoperative morbidity (RR 1.13, 95% CI 1.03-1.24), and higher readmission rates (RR 1.31, 95% CI 1.04-1.66) compared to patients without EBW undergoing MIRCS. No significant differences were found for length of hospital stay, intraoperative blood loss, surgical site infection, anastomotic leakage, gastrointestinal recovery, mortality, circumferential resection margin positivity, or lymph node harvest. CONCLUSION: Our review indicates a moderate increase in technical complexity and perioperative risk among patients with EBW undergoing MIRCS. These findings underscore the need for careful preoperative risk stratification and optimisation in this higher-risk patient cohort.