1 Department of Thoracic and Cardiovascular Surgery, Gachon University Gil Medical Center, Gachon University, 21 Namdong-daero 774beon-gi l, Namdong-gu, Incheon 405-760, Korea.
2 Department of Thoracic and Cardiovascular Surgery, Gachon University Gil Medical Center, Gachon University, 21 Namdong-daero 774beon-gi l, Namdong-gu, Incheon 405-760, Korea. Electronic address: kkyypark@gilhospital.com.