Short-term and long-term outcomes of natural orifice specimen extraction surgeries (NOSES) in rectal cancer: a comparison study of NOSES and non-NOSES

BACKGROUND: Natural orifice specimen extraction surgeries (NOSES) have been applied to colorectal cancer (CRC). Different types of NOSES have been proposed. Traditional laparoscopic CRC surgeries (non-NOSES) have been widely adopted in clinical practice. Therefore, the safety and feasibility of NOSES could be clarified by comparing with non-NOSES. METHODS: Consecutive cases who underwent NOSE or non-NOSE rectal surgeries were retrospectively collected at the Second Affiliated Hospital of Harbin Medical University between 1 January 2013 and 31 December 2018. Other inclusion criteria included patients with adenocarcinoma of the rectum within 15 cm of the anal verge, over the age of 18 and undergoing primary laparoscopic rectal resection. Patients who were lost to follow-up or had incomplete information were excluded. Basic characteristics including gender, tumor location, age, staging, treatment, and Body Mass Index (BMI) were analyzed. Short-term outcomes including comorbidities, intra-operative blood loss, hospital stay, gas exhaust time were compared between different NOSES and non-NOSES groups. Long-term outcomes including overall survival (OS) and disease-free survival (DFS) were also analyzed. Patients were followed-up during the inpatient period, at an outpatient clinic, or by phone call. RESULTS: A total of 196 NOSES cases and 243 non-NOSES cases were included. There was a sex difference between the two groups and other factors were comparable. Cases were divided into NOSES groups [including extra-abdominal resection (EVER), specimen extraction and extra-abdominal resection (EXER), and intra-abdominal resection and specimen extraction (IREX)] and non-NOSES groups. Differences in sex (P=0.016), BMI (with mean of 22.08, 22.00, 22.53, and 23.26 kg/m2, P=0.003), and staging (P=0.008) were observed between the four groups. There was a difference in the intra-operative blood loss between NOSES and non-NOSES groups (57.05±62.78, 52.65±68.19, 36.52±43.99 vs. 76.12±90.11 mL, P=0.002), in which NOSES groups had less blood loss. Furthermore, NOSES groups showed a better post-operative gas exhaust time (54.68±37.80, 45.06±24.69, 47.91±28.93 vs. 56.94±27.69 hours, P=0.012). NOSES groups also had fewer ileostomies (17 vs. 37, P=0.003). There was no difference in the long-term DFS and OS between the two groups. CONCLUSIONS: NOSES in rectal cancer showed better short-term outcomes and had comparable long-term outcomes compared with non-NOSE surgeries.