The Anti-reflux Effect of Double-flap Technique in Laparoscopic Proximal Gastrectomy.

Inclusion Criteria: 1. Age between 20 and 80 years, regardless of gender; 2. Patients diagnosed with gastric cancer through tissue biopsy; 3. Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1; 4. American Society of Anesthesiologists (ASA) classification of I to III; 5. Acceptable for laparoscopic proximal gastrectomy with preoperative examinations (based on endoscopic ultrasound and/or contrast-enhanced computed tomography of the thorax and abdomen) confirming the following oncological features: Primary tumor located in the upper part of the stomach (proximal 1/3 of the stomach) or gastroesophageal junction; Length of esophageal invasion ≤ 1 cm, tumor maximum diameter ≤ 4 cm; Preoperative staging T1-3N0M0 (based on AJCC 8th edition TNM clinical staging); 6. Voluntary signing of informed consent. Exclusion Criteria: 1. Received preoperative chemotherapy, radiotherapy, targeted therapy, or immunotherapy; 2. Presence of contraindications to surgery; 3. Multiple malignant lesions in the stomach; 4. Presence of other malignancies that may affect the preservation of stomach function; 5. Previous upper abdominal surgery (excluding cholecystectomy); 6. Preoperative examination reveals active peptic ulcer; 7. Patients who have received or are currently receiving treatment for systemic inflammatory diseases; 8. Pregnant or breastfeeding women; 9. Conditions deemed unsuitable for participation in this study by the investigator.