1 Department of Thoracic Surgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, 050011, China; Graduate School, Hebei Medical University, Shijiazhuang, Hebei, China.
2 Department of Thoracic Surgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, 050011, China. Electronic address: yuankundu@163.com.