1. Department of Vascular Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
2. Department of Gynecology, Jialing Branch of Nanchong Central Hospital, Nanchong, Sichuan 637919, P.R. China
3. Department of Anorectal, Nanchong Central Hospital, Nanchong, Sichuan 637000, P.R. China