1 Department of Gastrointestinal Surgery, The First Affiliated Hospital of Chengdu Medical College, Chengdu, 610500, Sichuan Province, China.
2 Department of Gastrointestinal Surgery, The First Affiliated Hospital of Chengdu Medical College, Chengdu, 610500, Sichuan Province, China. Electronic address: xiaojiangwei2018@163.com.