[1] Yonsei University College of Medicine,Department of Surgery, Yonsei University Health System
[2] Brain Korea 21 PLUS Project for Medical Science,Department of Medical Humanities & Social Medicine, Office of Biostatistics
[3] Ajou University School of Medicine,Department of Surgery
[4] Catholic Kwandong University College of Medicine,Department of Surgery
[5] International St. Mary’s Hospital,undefined
[6] Keimyung University School of Medicine,undefined