Clinical analysis of anastomotic fistula after anal preservation in 358 cases of rectal cancer and construction of risk prediction model: a single-center retrospective study.

ABSTRACT

OBJECTIVE: To develop and validate a simple prediction model for postoperative anastomotic leakage (AL) in patients with rectal cancer who underwent Dixon surgery by combining preoperative and intraoperative risk factors. METHODS: We conducted a retrospective study on 358 patients who underwent Dixon surgery for rectal cancer in the Affiliated Hospital of Youjiang Medical University for Nationalities (Guangxi Zhuang Autonomous Region, China). Based on logistic regression, the prediction model of AL after Dixon surgery was established and verified. RESULTS: The incidence of postoperative AL in these patients was 9.2% (33/358). The results of logistic regression analysis showed that age ≥60 years, male, Tumor-Node-Metastasis (TNM) stage ≥IIIa, preoperative obstruction, and the distance from the tumor to the anus ≤7 cm were the risk factors for AL after Dixon surgery, and intraoperative defunctioning stoma was the protective factor for AL after rectal Dixon surgery (all P<0.05). The prediction model construction Risk score =-4.275 + 0.851 × age + 1.047 × sex + 0.851 × distance + 0.934 × stage + 0.983 × obstruction. The area under receiver operating characteristic curve (ROC-AUC) was 0.762 (95% CI 0.667-0.856). The best cutoff, sensitivity and specificity were 0.14, 79.60%, and 83.10%, respectively. Hosmer-Lemeshow X2=6.876, P=0.550. Clinical validation results: the sensitivity, specificity, and accuracy of the model were 82.05%, 80.06%, and 80.25%, respectively. CONCLUSIONS: Both preoperative and intraoperative risk factors were used in the prognostic model. The prediction model established on this basis was well differentiated and highly calibrated, providing a good reference for the clinical prediction model of postoperative AL in rectal cancer patients undergoing Dixon surgery.