1. Department of Pancreatic and Biliary Surgery, First Affiliated Hospital of Harbin Medical University, 23 Youzheng Street, Nangang District, Harbin 150001, Heilongjiang Province, China
2. Department of Anesthesiology, First Affiliated Hospital of Harbin Medical University, 23 Youzheng Street, Nangang District, Harbin 150001, Heilongjiang Province, China
3. Department of Hepatobiliary and Pancreatic Surgery, Third Affiliated Hospital of Harbin Medical University, 150 Haping Street, Nangang District, Harbin 150001, Heilongjiang Province, China
4. Department of Abdominal Ultrasonography, First Affiliated Hospital of Harbin Medical University, 23 Youzheng Street, Nangang District, Harbin 150001, Heilongjiang Province, China