1. Department of Thoracic and Cardiovascular Surgery, Inje University Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea
2. Department of Thoracic and Cardiovascular Surgery, Hanyang University Seoul Hospital, Seoul, Korea
3. Department of Thoracic and Cardiovascular Surgery, Hanyang University College of Medicine, Seoul, Korea
4. Department of Thoracic and Cardiovascular Surgery, Hanyang University Guri Hospital, Guri, Korea