Less Invasive Endometrial Cancer Surgery with Extraperitoneal Pelvic and Para-aortic Lymphadenectomy via a Small Midline Abdominal Incision and the Retroperitoneal Approach

[Objective] To achieve less invasive lymphadenectomy in endometrial cancer patients, we performed extraperitoneal pelvic and para-aortic lymphadenectomy via a small midline abdominal incision with retroperitoneal approach. The feasibility and safety of this method were investigated. [Methods] Inclusion criteria were 1) endometrioid adenocarcinoma diagnosed by preoperative biopsy, 2) myometrial invasion by magnetic resonance imaging, and 3) no peritoneal dissemination or distant metastasis by computed tomography. Systematic extraperitoneal dissection of pelvic and para-aortic lymph nodes was performed via an approximately 12-cm midline lower abdominal incision, after which hysterectomy and bilateral salpingo-oophorectomy were done (extraperitoneal group). The historical control group was patients who underwent standard transperitoneal lymphadenectomy followed by hysterectomy and bilateral salpingo-oophorectomy. The two groups were compared for demographic characteristics, perioperative factors, and complications. [Results] A total of 62 patients were enrolled. Demographic and clinicopathological factors showed no differences between the extraperitoneal group (n = 34) and the historical control group (n = 28). The median number of pelvic (30 vs. 28) and para-aortic (14 vs. 17) nodes dissected was also similar. However, median intraoperative blood loss was significantly smaller in the extraperitoneal group than the control group (220 vs. 573 g). Median operating time (265 vs. 323.5 min), median laparotomy time (60 vs. 295 min), and median initial flatus time (8 vs. 32 hours) were all significantly shorter in the extraperitoneal group, while complications and severe postoperative pain were significantly less frequent. [Conclusions] Our new technique was feasible, safe, and less invasive than standard laparotomy. It is an alternative to laparoscope-assisted or robotic procedures.