Abstract:Objective To explore the risk factors of positive lateral margins after endoscopic submucosal dissection (ESD) for superficial esophageal cancer and precancerous lesions and to follow up with local recurrence.Methods Clinical data of patients who underwent ESD of esophagus, from January 2012 to December 2017, were collected. All these lesions were divided into positive lateral margin group or negative lateral margin group according to histopathology of lateral margin after ESD. Clinicopathological features of the lesions and the risk factors related to positive lateral margin were analyzed. The incidence of residual or local recurrence was followed up postoperatively and compared between the two groups.Results 194 lesions from 186 patients were included, and 37 and 157 lesions were divided into positive lateral margin group and negative lateral margin group, respectively. In the positive lateral margin group, there were 25 lesions of lateral margin diagnosed LGIN, 10 lesions of lateral margin diagnosed HGIN, 2 lesions of lateral margin diagnosed carcinoma. In the negative lateral margin group, there were 157 lesions. Univariate and multivariate analysis show significant association between iodine staining before marking the boundaries in esophageal ESD or not and area of sample. Late follow-up results showed that the rate of residual or local recurrence was 13.3% (4/30) in the positive lateral margin group, which was higher than 5.2% (7/134) in the negative lateral margin group, but it was not statistically significant.Conclusion No iodine staining before marking the boundaries in esophageal ESD and larger area of sample were associated with increasing incidence of positive lateral margins. In the case of positive lateral margins after ESD, especially when the histopathology of lateral margin indicated precancerous lesions, the patients could be followed up closely with endoscopy and further treatment was not required immediately.