A comparison of extraperitoneal versus transperitoneal laparoscopic or robotic para-aortic lymphadenectomy for staging of endometrial carcinoma

Objective The optimal surgical approach for complete lymphadenectomy in patients with endometrial cancer is controversial. The objective of our study was to compare the surgical outcomes of extraperitoneal laparoscopic, transperitoneal laparoscopic, and robotic transperitoneal para-aortic lymphadenectomy in endometrial cancer staging. Methods A retrospective review was performed on patients who underwent extraperitoneal or transperitoneal para-aortic lymphadenectomy for endometrial cancer staging from January 2007 to November 2012. Three patient groups were compared: extraperitoneal laparoscopic para-aortic lymphadenectomy, robotic hysterectomy and pelvic lymphadenectomy ("extraperitoneal group"; N = 34); laparoscopic hysterectomy and transperitoneal pelvic and para-aortic lymphadenectomy ("transperitoneal laparoscopic group"; N = 108); and robotic hysterectomy and transperitoneal pelvic and para-aortic lymphadenectomy ("transperitoneal robotic group"; N = 52). Fisher's exact test and Kruskal-Wallis test were used for statistical analysis, and statistical significance was defined as P < 0.05. Results The median number of para-aortic lymph nodes obtained was higher in the extraperitoneal group than in the transperitoneal laparoscopic and robotic groups (10, 5, and 4.5 nodes, respectively; P < 0.001). BMI was higher in the extraperitoneal group (median, 35.1 kg/m²) than in the transperitoneal groups but did not differ between the transperitoneal laparoscopic group (median, 28.4 kg/m²) and the transperitoneal robotic group (median, 30.2 kg/m²). Among patients with a BMI < 35 kg/m², the median number of para-aortic nodes harvested was higher in the extraperitoneal group than in the transperitoneal laparoscopic and robotic groups (9, 4, and 5 nodes, respectively; P < 0.01). The same pattern was observed among patients with a BMI ≥ 35 kg/m² (10, 6, and 3 nodes, respectively), but only the extraperitoneal group and the transperitoneal robotic group were significantly different (P = 0.001). There was no significant difference in median estimated blood loss between the extraperitoneal group and either the transperitoneal laparoscopic group (100 vs. 112.5 mL; P = 0.06) or the transperitoneal robotic group (100 vs. 67.5 mL; P = 0.23). The median operative time was longer in the extraperitoneal group (339.5 min; range, 242-453 min) than in the transperitoneal laparoscopic group (286 min; range, 101-480 min) and the transperitoneal robotic group (297.5 min, range 182-633 min) (P < 0.01). Conclusion Extraperitoneal laparoscopic para-aortic lymphadenectomy resulted in a higher number of para-aortic lymph nodes removed than transperitoneal laparoscopic or robotic lymphadenectomy. The extraperitoneal approach should be considered for endometrial cancer staging.