Gastrectomy with or without omentectomy for gastric cancer: A systematic review and meta-analysis

Background: Omentectomy is conventionally performed in the procedure of gastrectomy for gastric cancer. However, the clinical value and importance of omentectomy remain unclear. This meta-analysis investigated the benefits and safety of gastrectomy with or without omentectomy for patients with gastric cancer. Methods: A literature search was conducted in PubMed, Embase, and the Cochrane Library for studies comparing complete omentectomy with omentum preservation or partial omentectomy. Primary outcomes were overall survival, relapse-free survival, and incidences of recurrence and complications, whereas secondary outcomes were the total length of operation and the amount of blood loss. Results: Nine studies involving 3,561 patients were included. Our meta-analysis revealed no significant differences between omentectomy and omentum preservation in terms of the 5-year overall survival (risk ratio [RR] = 0.95, 95% confidence interval [CI] = 0.89–1.01), 5-year relapse free survival (RR: 0.96, 95% CI: 0.89–1.03), incidence of recurrence in the peritoneum or other visceral organs (RR: 1.13, 95% CI: 0.80–1.60 and RR: 1.06, 95% CI: 0.78–1.45, respectively), and incidence of complications (RR: 1.15, 95% CI: 0.89–1.50). Moreover, omentum preservation significantly reduced the total length of operation (mean difference [MD] 25.70, 95% CI: 3.23–48.17) and the amount of blood loss (MD: 56.29, 95% CI: 14.02–98.56). Conclusion: Omentectomy may not be necessary and can be omitted during gastrectomy for gastric cancer.