Learning curve of laparoscopic extraperitoneal para-aortic lymphadenectomy for endometrial carcinoma: A cumulative sum analysis

Objective: Minimally invasive surgery including lymphadenectomy for endometrial cancer is widely standardized for the management of endometrial cancer in recent decades. However, the learning curve for laparoscopic paraaortic lymphadenectomy is poorly reported, specifically that for the extraperitoneal approach. Methods: We examined the learning curve for laparoscopic extraperitoneal para-aortic lymphadenectomy by cumulative sum (CUSUM) analysis by retrospectively analyzing 134 patients with early-stage endometrial cancer who had undergone laparoscopic extraperitoneal para-aortic lymphadenectomy, including the first case. Data on the surgical factors that improved and were statistically correlated with the number of procedures experienced were extracted and used to create CUSUM curves. Results: The average time for para-aortic lymphadenectomy was 149.4 min to harvest an average of 65.3 paraaortic lymph nodes. Intra- and postoperative complications were observed in nine cases (6.7%). A switch to the transperitoneal approach was necessary in three cases (2.2%). The number of harvested para-aortic lymph nodes and the procedure time were strongly correlated with the number of procedures the patient underwent (p < 0.01). The CUSUM curve of the number of harvested para-aortic lymph nodes indicated an inflection point at the 51st case. The procedure time for para-aortic lymphadenectomy stabilized after the 59th case. CUSUM analysis of unexpected events, including intra- and postoperative complications and switch to the transperitoneal approach, showed an improved incidence at 60 cases and later. Conclusion: Gaining proficiency in laparoscopic extraperitoneal thorough para-aortic lymphadenectomy is associated with a long learning curve of over 60 procedures. Careful management is required when introducing the procedure.