Dechao Feng1, Zhenghao Wang1, Yubo Yang1, Ao Li1, Wuran Wei2. 1. Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Chengdu, China. 2. Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Chengdu, China - weiwuran@126.com.