Comparative long-term outcomes of natural orifice specimen extraction surgery and conventional laparoscopic colectomy for left-sided colorectal cancer: a propensity score-matched analysis.

Background: Natural orifice specimen extraction surgery (NOSES) is currently widely used in left-sided colorectal cancer. Some clinical comparative studies have been conducted, providing evidence of its safety and oncological benefits. However, these studies are typically characterized by small sample sizes and short postoperative follow-up periods. Consequently, in this research, the authors adopt the propensity score matching method to undertake a large-scale retrospective comparative study on NOSES colectomy for left-sided colorectal cancer, with the goal of further augmenting the body of evidence-based medical support for NOSES.

Methods: This retrospective study involved patients who underwent NOSES colectomy and conventional laparoscopic (CL) colectomy for left-sided colorectal cancer between January 2014 and April 2021. In the NOSES group, specimens were extracted through the anus with the help of a Cai tube (homemade invention: ZL201410168748.2). The patients were matched at a ratio of 1:1 according to age, sex, BMI, tumor diameter, tumor location (descending and splenic flexure colon/ sigmoid colon/ middle and upper rectum), tumor height from anal verge, ASA grade, previous abdominal surgery, clinical pathologic stage, preoperative CEA. After matching, 132 patients in the NOSES group and 132 patients in the CL group were eligible for analysis.

Results: Compared with CL group, NOSES group was associated with decreased postoperative maximum pain score (2.6±0.7 vs. 4.7±1.7, P=0.000), less additional analgesia required (6.8 vs. 34.8%, P=0.000), faster time to passage of flatus (2.3±0.6 days vs. 3.3±0.7 days, P=0.000), less wound infection (0.0 vs. 6.1%, P=0.007), and longer operative time (212.5±45.8 min vs. 178.0±43.4 min, P=0.000). No significant differences were observed in estimated blood loss, time to resume regular diet, postoperative hospital stay, conversion to open surgery or conventional minilaparotomy, total morbidity, readmission, mortality, pathologic outcomes, and Wexner incontinence score between groups. After a median follow-up of 63.0 months, the 5-year overall survival rates were 88.3 versus 85.0% (P=0.487), disease-free survival rates were 82.9 versus 83.6% (P=0.824), and the local recurrence rates were 4.4 versus 4.0% (P=0.667) in the NOSES and CL groups, respectively.

Conclusions: This study suggests that NOSES colectomy using a Cai tube for left-sided colorectal cancer is a safe and feasible option with better cosmetic results, less pain, faster recovery of gastrointestinal function, and comparable long-term clinical and oncologic outcomes to CL colectomy.