1. Kyusyu Study Group of Liver Surgery Fukuoka Japan
2. Department of Gastroenterological, Breast and Endocrine Surgery Yamaguchi University Graduate School of Medicine Ube Japan
3. Department of Gastroenterological Surgery Graduate School of Life Sciences Kumamoto University Kumamoto Japan
4. Department of Surgery and Science Graduate School of Medical Sciences Kyushu University Fukuoka Japan
5. Division of Hepatobiliary and Pancreatic Surgery Department of Surgery Kurume University Kurume Japan
6. Division of Hepato‐Biliary‐Pancreas Surgery Department of Surgery University of Miyazaki Faculty of Medicine Miyazaki Japan
7. Clinical Research Center and Department of Surgery National Hospital Organization Nagasaki Medical Center Nagasaki Japan
8. Department of Surgery Saga University Faculty of Medicine Saga Japan
9. Department of Gastroenterological and Pediatric Surgery Oita University Faculty of Medicine Graduate School of Medicine Oita Japan
10. Department of Surgery Oita Prefectural Hospital Oita Japan
11. Department of Surgery Saga‐Ken Medical Centre Koseikan Saga Japan
12. Department of Digestive Surgery, Breast and Thyroid Surgery Graduate School of Medicine Kagoshima University Kagoshima Japan
13. Department of Surgery Kagoshima Kouseiren Hospital Kagoshima Japan
14. Department of Surgery Gastroenterology and Hepatology Center Kitakyushu City Yahata Hospital Kitakyushu Japan
15. Department of Hepato‐Biliary‐Pancreatic Surgery Clinical Research Institute National Hospital Organization Kyushu Medical Center Fukuoka Japan
16. Department of Gastroenterological Surgery Faculty of Medicine Fukuoka University Fukuoka Japan
17. Department of Digestive and General Surgery Graduate School of Medicine University of the Ryukyus Nishihara Japan
18. Department of Surgery Yamaga City Medical Center Yamaga Japan
19. Department of Surgery Nagasaki University Graduate School of Biomedical Sciences Nagasaki Japan