1. Department of Hepatobiliary and Splenic Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, China
2. Department of Hepatobiliary Surgery, Weihai Central Hospital, Weihai, Shandong 264400, China
3. Department of Breast and Thyroid Surgery, Affiliated Zhongshan Hospital of Dalian University, Dalian, Liaoning 116001, China
4. Department of Anal Disease, Shenyang Coloproctology Hospital, Shenyang, Liaoning 110000, China