Effects of preservation of celiac branch of the vagus nerve after distal gastrectomy for gastric cancer. A prospective randomized controlled phase II study

INTERVENTION: distal gastrectomy with preservation of celiac branch of vagus nerve distal gastrectomy without preservation of celiac branch of vagus nerve CONDITION: gastric cancer PRIMARY OUTCOME: Primary outcome is the rate of gallstone two years after operation. INCLUSION CRITERIA: 1.gastric cancer with T1 invasion (lesion confined to the mucosa or the submucosa) and the tumors found to have submucosal invasion after EMR or ESD. 2.require distal gastrectomy 3.resectable lymph‐nodes with preservation of hepatic and celiac branch of vagus nerve 4.Age; 20‐90 years 5.Performance status 0‐1 6.resectable D1 lymph‐nodes with curability A or B 7.no abnormity in gallbladder or bile passage 8.informed consent is obtained