1) Department of Hepato–Biliary–Pancreatic and Transplant Surgery, Fukushima Medical University, Fukushima, Japan
2) Division of Gastrointestinal Surgery, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Japan
3) Department of Surgery, National Defense Medical College, Tokorozawa, Japan
4) Department of Surgery, Keio University School of Medicine, Tokyo, Japan
5) Department of Gastrointestinal Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
6) Department of Digestive/Liver Transplantation Surgery, Yokohama City University, Yokohama, Japan
7) Department of Health Policy and Management, School of Medicine, Keio University, Tokyo, Japan
8) Department of Healthcare Quality Assessment, The University of Tokyo, Tokyo, Japan
9) Hamamatsu University School of Medicine, Hamamatsu, Japan
10) Osaka General Medical Center, Osaka, Japan

Shigeru Marubashi¹⁾, Yoshihiro Kakeji²⁾, Hideki Ueno³⁾, Yuko Kitagawa⁴⁾, Yasuyuki Seto⁵⁾, Itaru Endo⁶⁾, Hiroaki Miyata⁷⁾⁸⁾, Hiroyuki Konno⁹⁾, Mitsukazu Gotoh¹⁰⁾