To analyze the clinical factors affecting the feasibility of natural orifice specimen extraction surgery (NOSES) in overweight patients with rectal cancer.

This research was conducted with the retrospective case-control study. We included overweight (BMI=24~28 kg/m²) rectal cancer patients who successfully performed NOSES and who failed to perform NOSES from January 2017 to December 2019 in Shanghai East Hospital, Department of Colorectal Surgery. Clinical data on age, gender, BMI, tumor size, tumor obstruction, tumor distance from the anal verge, mesorectum width was collected.

A total of 277 overweight patients with rectal cancer were enrolled (63 patients with NOSES). Univariate analysis showed that females (χ²=4.332, P=0.037), no tumor obstruction (χ²=9.421, P=0.002), distance from anal verge ＜5.0 cm (χ²=23.099, P＜0.001), maximum tumor diameter ≤5.0 cm (χ²=20.299, P＜0.001), mesorectum width in the anteroposterior dimension (AP)≤6.0 cm (χ²=31.359, P＜0.001) and mesorectum width from the left to right direction (LR)≤7.0 cm (χ²=5.754, P=0.016) were associated with successful NOSES, however, age (χ²=0.392, P=0.531) or abdominal surgery history (χ²=1.041, P=0.308) was not associated with the feasibility of NOSES. Multivariate logistics regression analysis suggested that the maximum tumor diameter ≤5.0 cm (OR=13.73, 95% CI: 1.81~104.18, P=0.011), distance from anal verge＜5.0 cm (OR=8.23, 95% CI: 2.20~30.81, P=0.002) and AP ≤6.0 cm (OR=3.79, 95% CI: 1.87~7.66, P＜0.001) were independent predictive factors of successful NOSES.

The maximum tumor diameter, distance from anal verge and AP were independent predictive factors of the feasibility of NOSES. Preoperative evaluation of these factors will help identify overweight rectal cancer patients suitable for NOSES.