1 Division of Colon and Rectal Surgery, Department of Surgery, Korea University Anam Hospital, Korea University College of Medicine, 73 Goryodae-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
2 Division of Colon and Rectal Surgery, Department of Surgery, Korea University Anam Hospital, Korea University College of Medicine, 73 Goryodae-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea. drkimsh@korea.ac.kr.