1. Department of Hepatobiliary Surgery, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China
2. Medical School , Ankang Vocational and Technical College, Ankang, Shaanxi, People’s Republic of China
3. Department of General Surgery, Air Force 986th Hospital, Xi’an, Shaanxi, People’s Republic of China
4. Department of Oncology Surgery, Shaanxi Provincial People’s Hospital, Xi’an, Shaanxi, People’s Republic of China
5. Department of Hepatobiliary Surgery, Shenmu Hospital, Shenmu, Shaanxi, People’s Republic of China