1 Graduate College, Tianjin Medical University, Tianjin, China.
2 Department of General Surgery, Tianjin Children's Hospital, Tianjin, China.
3 Department of General Surgery, Xiangyang Central Hospital, Xiangyang, Hubei, China.
4 Department of General Surgery, People's Hospital of Jiaozuo City, Jiaozuo, Henan, China.
5 Department of General Surgery, Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.