1. Department of General Surgery, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210000, P.R. China
2. Department of Minimally Invasive Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China
3. Department of General Surgery, Gaochun People's Hospital, Nanjing, Jiangsu 211300, P.R. China