1. Department of Hepatopancreatobiliary Surgery, Tianjin Medical University NanKai Hospital, Tianjin, China;
2. Tianjin Medical University, Tianjin, China;
3. Endoscopy Center, Integrated Chinese and Western Medicine Hospital, Tianjin University, Tianjin, China;
4. Department of Hepatopancreatobiliary Surgery, Integrated Chinese and Western Medicine Hospital, Tianjin University, Tianjin, China