Yu-Shang Yang1, Qi-Xin Shang1, Yong Yuan2, Long-Qi Chen3. 1. Department of Thoracic Surgery, West China Hospital of Sichuan University, Chengdu, Sichuan, China. 2. Department of Thoracic Surgery, West China Hospital of Sichuan University, Chengdu, Sichuan, China. yongyuan@scu.edu.cn. 3. Department of Thoracic Surgery, West China Hospital of Sichuan University, Chengdu, Sichuan, China. drchenlq@scu.edu.cn.