1 Department of Thoracic and Cardiovascular Surgery, Gachon University Gil Medical Center, 1198, Kuwol-Dong, Namdong-Ku, Incheon, 405-760, Republic of Korea.
2 Department of Thoracic and Cardiovascular Surgery, Gachon University Gil Medical Center, 1198, Kuwol-Dong, Namdong-Ku, Incheon, 405-760, Republic of Korea. Electronic address: pittz@hanmail.net.