Bacteriological and oncological safety of complete laparoscopic radical resection of colorectal cancer without incision anastomosis based on propensity-matched scores

Introduction
Complete laparoscopic radical resection of colorectal cancer without incision anastomosis is performed by means of natural orifice specimen extraction (NOSE), which avoids a large abdominal wall incision. Although this procedure is increasingly practiced, it is still underdeveloped, one reason being that controversy still exists regarding bacteriological and oncological safety.

Aim
To demonstrate the safety of complete laparoscopic radical resection of colorectal cancer without incision anastomosis in bacteriology and oncology.

Material and methods
This study was a retrospective study with prospectively collected data. This study continuously collected 420 patients who underwent colorectal cancer surgery in our hospital from January 2018 to March 2022. According to the different surgical methods, they were divided into the NOSE group (the natural orifice specimen extraction group) and the N-NOSE group (specimen removed through abdominal wall auxiliary incision). The two groups were matched 1 : 1 using the propensity score matching (PSM) method to balance at baseline. Bacteriological and oncological outcomes, short-term complications, and long-term prognosis were compared between the two groups.

Results
One hundred and eighty-four of the 420 included patients were successfully matched. The differences in gender, body mass index, T stage, N stage, and diabetes status between the two groups after matching were not statistically significant. There were no significant differences in oncological outcomes, short-term complications, and 2-year postoperative disease-free survival between the two groups. There was no significant correlation between positive bacterial culture results and intra-abdominal infection.

Conclusions
Compared with traditional laparoscopic surgery, complete laparoscopic radical resection of colorectal cancer without incision anastomosis has satisfactory bacteriological and oncological effects and is worthy of further clinical promotion.