1 Department of Cardiology, The Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, People's Republic of China.
2 Department of General Surgery, The Second Xiangya Hospital, Central South University, No. 139, Mid Renmin Road, Furong, Changsha, 410011, Hunan, People's Republic of China.
3 Department of General Surgery, The Second Xiangya Hospital, Central South University, No. 139, Mid Renmin Road, Furong, Changsha, 410011, Hunan, People's Republic of China. zhangdanhua@csu.edu.cn.