Abstract: Objective To explore the clinical causes of unplanned reoperations after radical resection of esophageal cancer, in order to gain a deeper understanding of reducing the occurrence of unplanned reoperation after radical resection of esophageal cancer. 
Methods The clinical data of 1 395 patients who underwent radical resection for esophageal cancer in thoracic surgery group of the Fourth Hospital of Hebei Medical University were retrospectively analyzed, including 1 012 males and 383 females, with an average age of (64.21±7.27) years. The tumors were located in the cervical esophagus in 1 case, the upper thoracic esophagus in 154 cases, the middle thoracic esophagus in 589 cases, and the lower thoracic esophagus in 651 cases. Pathological stage included 782 cases (56.06%) in stage Ⅰ to Ⅱ, 613 cases (43.94%) in stage Ⅲ to Ⅳ A. 
Results In total, 25 cases (1.79%) of 1 395 patients who underwent radical resection for esophageal cancer had unplanned reoperation for different reasons. Univariate analysis of clinical data of included patients showed that age ≥65 years, body mass index (BMI)＜18, pathological stage Ⅲ-ⅣA and smoking rate in the non-planned operation group were higher than those in the normal operation group, and the difference was statistically significant (P＜0.05). The above factors were included in multivariate Logistic regression analysis, and the results showed that age ≥65 years (OR=0.38，95%CI： 0.161-0.896， P=0.027), BMI＜18(OR=0.176， 95%CI： 0.062-0.498， P=0.001) and smoking (OR=0.314， 95%CI： 0.128-0.771， P=0.011) were independent influencing factors for patients undergoing unplanned reoperation after radical resection of esophageal cancer. Anastomotic fistula (7/25, 28%), severe pulmonary complications (7/25, 28%), and postoperative bleeding (6/25, 24%) were the main causes of unplanned reoperation. 
Conclusion Advanced age, low BMI and smoking are high risk factors for unplanned reoperation after radical resection of esophageal cancer, and the main causes include anastomotic fistula, severe pulmonary complications and postoperative bleeding. For preoperative assessment of high-risk patients, the key to reducing the probability of unplanned reoperation is to improve perioperative management, reduce preoperative nutritional risks, and ensure prevention and supervision.

Key words: esophageal neoplasms, reoperation, influencing factor analysis