1 Department of Gastrointestinal Surgery, The Second Hospital, Cheeloo College of Medicine, Shandong University, No. 247 Beiyuan Street, Jinan, 250033, China.
2 Department of General Surgery, Shanghai General Hospital, School of Medicine, Shanghai Jiaotong University, 85 Wujin Road, Shanghai, 200080, China.
3 Department of Gastrointestinal Surgery, The Second Hospital, Cheeloo College of Medicine, Shandong University, No. 247 Beiyuan Street, Jinan, 250033, China. dingyinlu@126.com.