1 Department of General Surgery, Xiangya Hospital, Central South University, Changsha, 410008, China.
2 Department of Thyroid and Breast Surgery, Hunan Provincial People's Hospital, The First Affiliated Hospital of Human Normal University, Changsha, 410008, China.
3 Department of General Surgery, Xiangya Hospital, Central South University, Changsha, 410008, China. zhangzhejia@csu.edu.cn.
4 Department of General Surgery, Xiangya Hospital, Central South University, Changsha, 410008, China. changshi@csu.edu.cn.