Sung, Kim, Wook; Ryul, Lee, Jeong; Bong, Kim, Ki; Whan, Sung, Sook; Hyuk, Ahn; Jin, Kim, Yong; Hurn, Chae; Hyun, Kim, Joo; Ryang, Rho, Joon; Whan, Kim, Chong; Phill, Suh, Kyung; Kyun, Lee, Young; Sung, Kim, Wook, Department of Thoracic and Cardiovascular Surgery, College of Medicine, Seoul National University; Ryul, Lee, Jeong, Department of Thoracic and Cardiovascular Surgery, College of Medicine, Seoul National University; Bong, Kim, Ki, Department of Thoracic and Cardiovascular Surgery, College of Medicine, Seoul National University; Whan, Sung, Sook, Department of Thoracic and Cardiovascular Surgery, College of Medicine, Seoul National University; Hyuk, Ahn, Department of Thoracic and Cardiovascular Surgery, College of Medicine, Seoul National University; Jin, Kim, Yong, Department of Thoracic and Cardiovascular Surgery, College of Medicine, Seoul National University; Hurn, Chae, Department of Thoracic and Cardiovascular Surgery, College of Medicine, Seoul National University; Hyun, Kim, Joo, Department of Thoracic and Cardiovascular Surgery, College of Medicine, Seoul National University; Ryang, Rho, Joon, Department of Thoracic and Cardiovascular Surgery, College of Medicine, Seoul National University; Whan, Kim, Chong, Department of Thoracic and Cardiovascular Surgery, College of Medicine, Seoul National University; Phill, Suh, Kyung, Department of Thoracic and Cardiovascular Surgery, College of Medicine, Seoul National University; Kyun, Lee, Young, Department of Cardiovascular Surgery, Sejong General Hospital Supported by grants from 1990 SNUH Clinical Research Fund (SAGE Publications, 1993)