1 Department of Thoracic Surgery, The Second Affiliated Hospital of Soochow University, Suzhou, People's Republic of China.
2 Department of Thoracic Surgery, Suzhou Kowloon Hospital Shanghai, Jiaotong University School of Medicine, Suzhou, People's Republic of China.
3 Department of Thoracic Surgery, The Second Affiliated Hospital of Soochow University, Suzhou, People's Republic of China. Electronic address: chentongt@sina.com.