1 Department of Gastrointestinal Surgery, Peking University First Hospital, Peking University, 8 Xi ShiKu Street, Beijing, 100034, People's Republic of China.
2 Department of Colorectal Surgery, Jiangsu Province Hospital of Chinese Medicine, The Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, 210029, People's Republic of China.
3 Department of Gastrointestinal Surgery, Peking University First Hospital, Peking University, 8 Xi ShiKu Street, Beijing, 100034, People's Republic of China. Electronic address: chenzeyang_pku@163.com.