1. Department of Urology, Hexi University Affiliated Zhangye People's Hospital, Zhangye, Gansu 734000, P.R. China
2. Endoscopy Center, Hexi University Affiliated Zhangye People's Hospital, Zhangye, Gansu 734000, P.R. China
3. Department of General Surgery, Gaotai Silk Road Ciren Hospital, Zhangye, Gansu 734000, P.R. China
4. Institute of Urology, Hexi University, Zhangye, Gansu 734000, P.R. China