Demonstrated the short- and long-term efficacy of NOSES by comparing abdominal incision for specimen extraction and natural orifice specimen extraction surgery (NOSES) in the treatment of rectal cancer.

We retrospectively analyzed the clinical data of 217 patients who underwent NOSES or conventional minimally invasive surgery in the department of gastrointestinal surgery of the Second Affiliated Hospital of Dalian Medical University from January 2018 to December 2020. According to the different methods of the removal of surgical specimen, all patients were divided into the following groups: NOSES group (experimental group) and the auxiliary incision group (control group). PSM was used to balance the baseline data, there were 63 patients in the NOSES group and 63 patients in the auxiliary incision group, respectively; perioperative data, pathological data and the long-term efficacy were analyzed among two groups.

Compared to the auxiliary incision group, patients in the NOSES group had shorter incision lengths (t=-19.791, P＜0.001), earlier out-of-bed time (t=-5.978, P＜0.001), shorter postoperative gastrointestinal recovery time (t=-7.656, P＜0.001) and lower VAS score of the incision pain (postoperative 12 h: t=-4.372, P＜0.001; postoperative 24 h: t=-5.835, P＜0.001), these differences were statistically significant. The incidence of incision complications in the NOSES group was significantly lower than that in the auxiliary incision group(0 vs. 9.5%, χ²=4.375; P=0.028). Postoperative complications were graded by Clavien-Dindo classification, postoperative complications occurred in 8 patients in the NOSES group (12.7%), the amounts of Clavien-Dindo grade Ⅰ, Ⅱ and Ⅲ complications were 3 (4.8%), 2 (3.2%) and 3 (4.8%); compared to the auxiliary incision group, the NOSES group had lower rate of postoperative complications, but no difference was statistically significant (12.7% vs. 22.2%, χ²=1.983; P=0.159). Compared the pathological data and the long-term efficacy of two groups, there were all no significant differences in the number of dissected lymph nodes (t=0.603, P=0.548), the length of proximal margin (t=-0.110, P=0.912) and distal resection margin (t=-0.126, P=0.900), overall survival (χ²=0.002, P=0.962) and disease-free survival (χ²=0.625, P=0.429).

NOSES has obviously advantages of less postoperative pain, smaller damage and earlier postoperative recovery, provides satisfactory efficacy and acceptable safety, and similar long-term oncologic outcomes compared with conventional minimally invasive surgery.