1. Department of Surgery, Kyungpook National University School of Medicine, Daegu, Korea.
2. Department of Surgery, Yeungnam University College of Medicine, Daegu, Korea.
3. Department of Surgery, Catholic University of Daegu School of Medicine, Daegu, Korea.
4. Department of Surgery, Keimyung University School of Medicine, Daegu, Korea.
5. Biomedical Research Institute, Kyungpook National University School of Medicine, Daegu, Korea.