To assess the safety and efficacy of natural orifice specimen extraction surgery(NOSES) of 3D laparoscopic ultra-low anterior resection for low rectal cancer.

We retrospectively analyzed the clinical and pathological features of 80 patients undergoing 3D laparoscopic ultra-low anterior resection for low rectal cancer during January 2018 to December 2020 in Gastrointestinal and Colorectal Surgery Department of Shanghai East Hospital affiliated to Tongji University. All patients were divided into two groups according to the surgical methods: thirty-four cases were divided into the NOSES group who underwent natural orifice specimen extraction surgery of 3D laparoscopic ultra-low anterior resection. Fourty-six cases were divided into traditional group who underwent traditional approach of 3D laparoscopic ultra-low anterior resection. A comparative, retrospective analysis was performed between the two groups in operative safety index and efficacy.

Age, gender, body mass index, tumor location, diameter of tumor, tumor stage were not significantly different between the two groups(P＞0.05); As compared to the traditional group, there were no significant difference between two groups in terms of blood loss(t=0.192, P=0.848), operation time(t=1.527, P=0.131), postoperative complications(χ²=1.368, P=0.850), first anal exhaust time(t=1.126, P=0.263), postoperative eating liquid time(t=0.863, P=0.391) and postoperative pathology features(χ²=0.224, P=0.894). NOSES group was associated with significantly less estimated mean postoperative hospitalization time [(9.97±2.58) days vs.(12.28±3.80) days, t=3.064; P=0.003]. The VAS score of the incision pain of the first to third day after operation in group NOSES was significantly lower than that in traditional group (postoperative 1d: t=3.586, P=0.001; postoperative 2d: t=2.942, P=0.004; postoperative 3d: t=2.792, P=0.007). According to WIS criteria, there were 76.6% patients whose anal sphincter function was good (WIS≤10), and there was no patient with serious anal incontinence.

By using both two surgical methods, radical resection of tumors could be achieved effectively in accordance with the principles of TME, and the operative effect was comparable. NOSES of 3D laparoscopic ultra-low anterior resection for low rectal cancer has advantages in less estimated postoperative incision pain and postoperative hospitalization time, it is a safe and reliable treatment.