To assess the comparative efficacy of laparoscopic natural orifice specimen extraction surgery (NOSES Ⅱ) and laparoscopic radical resection (LAP) for middle rectal cancer.

In this retrospective analysis conducted from August 2013 to November 2018 at the Department of Colorectal Cancer Surgery, the Second Affiliated Hospital of Harbin Medical University, 141 patients with rectal cancer were enrolled and divided into 2 groups by treated with NOSES or conventional LAP. The NOSES Ⅱ group included 55 cases and the LAP group included 86 cases. The operative time, intraoperative blood loss, postoperative exhaust time, feeding time, length of hospital stay, complications, prognosis and other differences between the two groups were compared.

Forty-seven pairs of cases were successfully matched and evaluated. The operative and postoperative information of the two groups was analyzed and compared, among which, there were no statistically significant differences in the operative duration intraoperative blood loss, lymph node dissection, postoperative follow-up and postoperative anal function evaluation (P＞0.05). The NOSES Ⅱ group had lower incidences of total postoperative complications (6.4% vs.21.3%, χ²=6.085, P=0.036), shorter postoperative exhaust time (38 h vs.48 h, t=-2.639, P=0.008),shorter postoperative feeding time (59 h vs.84 h, t=-3.330, P=0.001) and shorter total length of postoperative hospital stay [12 (6~18) vs.12 (9~30), t=-1.460, P=0.004] than the LAP group. Lower pain scores and the use of analgesics in the first, third and fifth postoperative days were recorded in the NOSESⅡgroup as compared to the LAP group (t=-4.463, P＜0.001), (t=-4.975, P＜0.001), (t=-5.706, P＜0.001). In addition, in terms of survival analysis, two groups of patients with postoperative DFS and OS were not statistically difference (P＞0.05).

The results indicate that NOSES Ⅱ is a relatively safe and effective way for middle rectal cancer radical resection, with ensured efficacy of the operation not increasing risk of surgery, potential to reduce the total complications after surgery, shortened postoperative hospitalization duration, shortened postoperative exhaust time, shortened eating time, shortened postoperative time, improved pain relief. This article should ensure that NOSES has obvious advantages over the conventional laparoscopic surgery.