Impacts of trans-anal tube placement in patients with sigmoid colon cancer: Risk verification analysis using inverse probability weighting analysis

Purpose Anastomotic leakage (AL) is a serious postoperative complication that affects short- and long-term outcomes. The use of a trans-anal drainage tube (TDT) is reported to prevent AL in rectal cancer patients, but its value in sigmoid colon cancer patients is unknown. Methods Admitted to the study were 379 patients who underwent surgery for sigmoid colon cancer between 2016 and 2020. Patients were divided into two groups according to the placement (n = 197) or nonplacement of a TDT (n = 182). To determine the factors affecting the association between TDT placement and AL, we estimated average treatment effects by stratifying each factor using the inverse probability of treatment weighting method. The association between prognosis and AL was evaluated in each identified factor. Results Factors associated with postsurgical insertion of a TDT were advanced age, male sex, high body mass index (BMI), poor performance status, and presence of comorbidities. TDT placement was associated with a significantly lower AL in male patients (odds ratio [OR], 0.22; 95% confidence interval [CI], 0.07-0.73; P = .013) and for BMI >= 25 kg/m(2) (OR, 0.13; 95% CI, 0.02-0.65; P = .013). In addition, there was a significant association of AL with poor prognosis in patients with BMI >= 25 kg/m(2) (P = .043), age > 75 y (P = .021), and pathological node-positive disease (P = .015). Conclusion Sigmoid colon cancer patients with BMI >= 25 kg/m(2) are the most appropriate candidates for postoperative TDT insertion, in terms of reduced incidence of AL and improved prognosis.