This single-center retrospective cohort study was conducted at the Center for Bariatric and Metabolic Surgery, China-Japan Friendship Hospital, Beijing, China, and is reported in accordance with the STROBE guidelines for observational studies [18]. Consecutive eligible patients were enrolled between 28 September 2022 and 29 July 2025; each patient was followed under a standardized 12-month schedule, with the last follow-up visit on 16 July 2026 and data extraction on 17 July 2026. The study protocol was approved by the institutional ethics committee , and the requirement for individual informed consent was waived because of the retrospective design and use of de-identified data. To minimize selection and information bias, consecutive eligible patients were enrolled, all procedures were performed by a single operator, symptoms were assessed with a standardized questionnaire on a fixed follow-up schedule, and data were extracted in de-identified form. All consecutive eligible patients during the study period were included; no a priori sample-size calculation was performed given the exploratory design. There were no missing data for analyzed variables; patients with incomplete baseline or follow-up data were excluded.

Consecutive patients who underwent ECBP for refractory GERD after LSG were screened. Eligible patients met the following inclusion criteria: (i) previous LSG for obesity; (ii) refractory GERD, defined as persistent typical reflux symptoms despite standard-dose PPI therapy for at least 8 consecutive weeks; (iii) age ≥18 years; and (iv) completion of a standardized 12-month postoperative follow-up. Exclusion criteria included: (i) hiatal hernia identified on preoperative endoscopy, because band ligation of the cardia is not expected to correct the anatomical defect associated with a hiatal hernia, and such patients are generally referred for alternative management; (ii) previous gastric or anti-reflux surgery other than LSG; (iii) contraindications to endoscopic intervention; and (iv) incomplete baseline or follow-up data. All patients underwent routine preoperative endoscopic evaluation to confirm the absence of hiatal hernia and to characterize the gastroesophageal junction. A total of 47 patients were included (ECBP alone, n = 38; ECBP plus BTX, n = 9); patients who did not complete the 12-month follow-up were excluded, and all 47 included patients completed the standardized 12-month schedule.