1. Department of Gastrointestinal Surgery, Hunan Provincial People’s Hospital (The First Affiliated Hospital of Hunan Normal University), Changsha 410005, Hunan, China
2. Department of Anesthesiology, Third Xiangya Hospital of Central South University, Changsha 410008, Hunan, China
3. Department of Pathology, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
4. National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
5. Department of Hepatobiliary Surgery, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China