1. Department of General Surgery, Central South University, Changsha, China.
2. Institute of Medical Sciences, Central South University, Changsha, China.
3. Department of General Surgery, Chenzhou No. 1 People's Hospital, Chenzhou, China.
4. Department of Geriatrics, Xiangya International Medical Center–Surgical Ward, Xiangya Hospital, Central South University, Changsha, China.