Risk factors for anastomotic leakage and its impact on survival outcomes in radical multivisceral surgery for advanced ovarian cancer: an AGO-OVAR.OP3/LION exploratory analysis

Background: Anastomotic leakage is a significant complication following bowel resection in cytoreductive surgery for ovarian cancer. Previous studies have highlighted the detrimental effects of anastomotic leakage on patients’ postoperative course. However, there is still a lack of precise identification of the high-risk population and established strategies for preventing its occurrence. Materials and methods: Patients who underwent bowel resection within the surgical phase III trial AGO-OVAR.OP3/LION investigating the impact of systematic pelvic and paraaortic lymphadenectomy in cytoreductive surgery for primary ovarian cancer were included in this analysis. All patients in the AGO-OVAR.OP3/LION trial had undergone complete cytoreduction with no macroscopic residual disease. We analyzed the occurrence of anastomotic leakage regarding surgical procedure (non-lymphadenectomy vs. lymphadenectomy and non-stoma vs. stoma) using the Fisher test. Risk factors for anastomotic leakage and its prognostic impact on survival were analyzed. Results: Overall rate of anastomotic leakage was 7.1%. Notably, the Non-lymphadenectomy subgroup had a lower anastomotic leakage rate of 3.0% compared to the lymphadenectomy subgroup (11.2%, P = 0.005). The use of protective stoma placement resulted in an anastomotic leakage rate of 5.5% regardless of lymphadenectomy compared to the Non-Stoma subgroup (7.5%, P = 0.78). Increased blood loss (odds ratio [OR] 1.04 per 100cc, 95% confidence interval [CI] 1.0001–1.09) and lymphadenectomy (OR 3.67, 95% CI 1.41–11.40) were associated with a higher risk of anastomotic leakage. Although anastomotic leakage demonstrated a numerical detrimental impact on median progression-free survival (PFS) (18 months with anastomotic leakage vs. 19 months with Non-anastomotic leakage, hazard ratio [HR] 0.86; 95% CI 0.5 to 1.4, P = 0.53) and median overall survival (OS) (31 months with anastomotic leakage vs. 58 months with Non-anastomotic leakage, HR 0.69; 95% CI 0.4 to 1.2, P = 0.17), the differences were not statistically significant. Conclusion: Anastomotic leakage rates were lower in the Non-lymphadenectomy arm, the current standard of care. Blood loss and lymphadenectomy, as surrogate markers for extensive surgery, were associated with increased risk for anastomotic leakage. These findings highlight the importance of strategies to reduce surgical complexity and perioperative risk to improve clinical outcomes.