A Multicenter Randomized Controlled Study of the Effect of Laparoscopic Preservation of the Pylorus

Inclusion Criteria: 1. 18 years old \< age \< 75 years old; 2. primary gastric lesions were diagnosed as gastric adenocarcinoma by biopsy; 3. the preoperative clinical stage was T1N0M0 according to ajcc-7thtnm; 4. it is predicted that R0 can be obtained by pylorogastric gastrectomy and D1 + lymph node dissection; 5. preoperative ECoG physical state score 0 / 1; 6. preoperative ASA score I-III; 7. informed consent of patients. Exclusion Criteria: 1. pregnant or lactating women; suffering from serious mental illness; 2. the history of upper abdominal surgery (except laparoscopic cholecystectomy); 3. history of gastric surgery (including ESD / EMR for gastric cancer); 4. preoperative imaging examination showed regional enlarged lymph nodes; 5. having other malignant diseases within 5 years; 6. patients with gastric cancer who have received new adjuvant therapy or recommended new adjuvant therapy; 7. there was a history of unstable angina or myocardial infarction within 6 months; 8. have a history of cerebral infarction or cerebral hemorrhage within 6 months; 9. there was a history of continuous systemic corticosteroid therapy within 1 month; 10. simultaneous surgical treatment of other diseases is needed; 11. gastric cancer with complications (hemorrhage, perforation, obstruction) requires emergency surgery; 12. FEV1 of pulmonary function examination was less than 50% of the predicted value.