1. Department of Thoracic Surgery, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
2. Department of Thoracic Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
3. Department of Thoracic Surgery, Guiyang Public Health Clinical Center, Guiyang, Guizhou 550003, P.R. China