Government of the People's Republic of China - Tangdu Hospital, Department of General Surgery, Government of the People's Republic of China - Department of General Surgery, Government of the People's Republic of China - Xijing Hopsital of Digestive Diseases, Department of Liver Disease and Digestive Interventional Radiology, Aeromedicine Identification and Training Centre of Air Force -Department of Drug and Equipment, Government of the People's Republic of China - Tangdu Hospital, Department of General Surgery, Government of the People's Republic of China - Xijing Hopsital of Digestive Diseases, Department of Liver Disease and Digestive Interventional Radiology, Government of the People's Republic of China - Tangdu Hospital, Department of General Surgery, Government of the People's Republic of China - Tangdu Hospital, Department of General Surgery, Government of the People's Republic of China - Tangdu Hospital, Department of Gastroenterology, Government of the People's Republic of China - Tangdu Hospital - Department of General Surgery, Government of the People's Republic of China - Tangdu Hospital - Department of General Surgery and Government of the People's Republic of China - Tangdu Hospital, Department of Gastroenterology