[1] Seoul Natl Univ, Dept Surg, Bundang Hosp, Coll Med, Songnam 463707, South Korea
[2] Yonsei Univ, Coll Med, Dept Surg, Gangnam Severance Hosp, Seoul, South Korea
[3] Chonnam Natl Univ, Sch Med, Dept Surg, Kwangju, South Korea
[4] Sungkyunkwan Univ, Sch Med, Samsung Med Ctr, Dept Surg, Seoul, South Korea
[5] Korea Inst Radiol & Med Sci, Korea Canc Ctr Hosp, Dept Surg, Seoul, South Korea
[6] Dong A Univ, Coll Med, Dept Surg, Pusan, South Korea
[7] Soonchunhyang Univ, Bucheon Hosp, Coll Med, Dept Surg, Puchon, South Korea
[8] Yeung Nam Univ, Coll Med, Dept Surg, Taegu, South Korea
[9] Natl Canc Ctr, Ctr Liver Canc, Dept Surg, Goyang, South Korea
[10] Korea Univ, Ansan Hosp, Coll Med, Dept Surg, Ansan, South Korea
[11] Seoul Metropolitan Govt Seoul Natl Univ, Boramae Med Ctr, Dept Surg, Seoul, South Korea
[12] Catholic Univ Korea, Seoul St Marys Hosp, Coll Med, Dept Surg, Seoul, South Korea
[13] Chonbuk Natl Univ Hosp & Med Sch, Dept Surg, Jeonju, South Korea
[14] Eulji Univ, Coll Med, Dept Surg, Taejon, South Korea
[15] Ewha Womans Univ, Mokdong Hosp, Sch Med, Dept Surg, Seoul, South Korea
[16] Gyeongsang Natl Univ, Gyeongsang Natl Univ Hosp, Gyeongnam Reg Canc Ctr, Inst Hlth Sci,Dept Surg, Jinju, South Korea
[17] Konyang Univ, Konyang Univ Hosp, Coll Med, Dept Surg, Taejon, South Korea
[18] Soonchunhyang Univ, Coll Med, Dept Surg, Seoul, South Korea