Jeong Su Cho1, Up Huh2, Jonggeun Lee3, Hyo Young Ahn1. 1. Department of Thoracic and Cardiovascular Surgery, Pusan National University School of Medicine, Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea. 2. Department of Thoracic and Cardiovascular Surgery, Pusan National University School of Medicine, Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea. Electronic address: tymfoo82@gmail.com. 3. Department of Thoracic and Cardiovascular Surgery, School of Medicine Jeju National University Hospital, Jeju National University, Jeju, Republic of Korea.