Hu Liao1, Zhilan Xiao2. 1. Department of Thoracic Surgery, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Wuhou District, Chengdu 610041, Sichuan, China. Electronic address: liaotiger_198653@163.com. 2. West China School of Medicine, Sichuan University, Sichuan, China.