1 Department of Thoracic and Cardiovascular Surgery, Chonbuk National University Medical School, 20 Geonji-Ro, Deokjin-Gu, Jeonju, Chonbuk, 561-712, Republic of Korea.
2 Department of Thoracic and Cardiovascular Surgery, Chonbuk National University Medical School, 20 Geonji-Ro, Deokjin-Gu, Jeonju, Chonbuk, 561-712, Republic of Korea. Electronic address: jobchoi@jbnu.ac.kr.