Ding Yuan1, Jichun Zhao2, Bin Huang1, Yi Yang1. 1. Department Vascular Surgery of West China Hospital, Sichuan University, Chengdu, Sichuan, China. 2. Department Vascular Surgery of West China Hospital, Sichuan University, Chengdu, Sichuan, China. Electronic address: zhaojc3@163.com.