Kyung Hwa Kim1, Jong Bum Choi2, Min Ho Kim2. 1. Department of Cardiothoracic and Vascular Surgery, Chonbuk National University Medical School, Jeonju, Republic of Korea. Electronic address: tcskimgh@gmail.com. 2. Department of Cardiothoracic and Vascular Surgery, Chonbuk National University Medical School, Jeonju, Republic of Korea.