The primary endpoint was defined as incidence of delayed gastric emptying by ISGPS criteria. The secondary endpoint was defined as incidence of other postoperative morbidity. Patients were recruited into this study before surgery, on the basis of whether pancreatic head resection was anticipated for pancreatic head and periampullary disease, and an appropriate informed consent was obtained. Exclusion criteria was 1) patients who have the history of gastrectomy, 2) patients who have severe cardiorespiratory dysfunction, 3) patients who have liver cirrhosis or are receiving dialysis, and 4) patients who were diagnosed inadequate for this study by a physician.