Hai Liao1, Tao Wu2. 1. Department of Urology, The First People's Hospital of Suining, Suining, 629000, Sichuan, People's Republic of China. 2. Department of Urology, Affiliated Hospital of North Sichuan Medical College, Wenhua road 57, Shunqing district, Nanchong, 637000, Sichuan, People's Republic of China. alhawking@163.com.