A randomized controlled study of long term nutritional management by elemental diet after pancreaticoduodenectomy for biliary tract and pancreatic cancer

INTERVENTION: Patients administered elemental diet (ELENTAL) from enteral feeding tube for 3 month postoperatively. Patients administered elemental diet (ELENTAL) from enteral feeding tube until beginning of oral intake. CONDITION: Biliary tract cancer, Pancreatic cancer PRIMARY OUTCOME: Neutral fat, Total cholesterol, ALT, AST, GGTP, Total protein, albumin, pre‐albumin, lymphoid count, serum amino acid(Histidine), SF‐36, period to return work, oral intake of baseline, 1, 3 and 6 month after operation ; ; CA19‐9 level, toxicity of chemotherapy SECONDARY OUTCOME: Body weight INCLUSION CRITERIA: Patients received pancreaticoduodenectomy for bile duct cancer or pancreatic cancer