1. Department of Surgery, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China
2. Department of Surgery, Guangxi Traditional Chinese Medical University Affiliated First Hospital, Nanning, Guangxi Zhuang Autonomous Region 530023, P.R. China
3. Department of Gastrointestinal and Peripheral Vascular Surgery, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China