Complete mesocolic excision versus D2 lymphadenectomy in right hemicolectomy: a meta-analysis of propensity score matched studies and randomized controlled trials

Introduction: The complete mesocolic excision (CME) in right-sided hemicolectomy could result in higher lymph node yield and decreased local recurrence. However, this approach could increase intraoperative and postoperative complications. Therefore, our meta-analysis aims to demonstrate the outcomes of CME versus D2 conventional lymphadenectomy in right-side colon cancer. Methods: We searched MEDLINE, Cochrane Central Register of Clinical Trials, and Scopus for studies published until April 2024. Odds ratios (OR) with 95% confidence intervals (CIs) were pooled using a random-effects model. Heterogeneity was assessed using the Cochran Q test and I-2 statistics, with P values <0.10 and I-2 >25% considered significant. Statistical analysis was performed using R Software, version 4.1.2. Results: Three randomized controlled trials and four observational studies comprising 2296 patients were included, of whom 1138 (49.6%) were submitted to the CME and 1158 (50.4%) to the conventional D2 lymphadenectomy. CME was associated with decreased local recurrence rates (OR 0.07; 95% CI 0.001 to 0.36; P = 0.002). There were no significant differences between groups in overall complications, severe complications, intraoperative complications, blood loss, and 30-day mortality. No difference between groups was observed in distance metastasis and 3-year disease-free survival. Conclusion: In this meta-analysis, CME significantly decreases local recurrence rates compared with D2 conventional lymphadenectomy in patients with right-side colon cancer. No significant difference was observed between groups in rates of overall complications, severe complications, intraoperative complications, blood loss, and 30-day mortality.