1. West China Hospital, Sichuan University; Department of Gastrointestinal Surgery; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041
2. West China Hospital, Sichuan University; Bile Duct Surgery; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041
3. Sichuan University, West China Hospital; Institute of Digestive Surgery; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041
4. West China Hospital, Sichuan University; Institute of Digestive Surgery; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041
5. West China Hospital, Sichuan University; Department of Laboratory Medicine; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041
6. Erasmus Medical Center; Department of Surgery; PO Box 2040 Rotterdam Netherlands 3000 CA
7. Institute for Quality and Efficiency in Health Care (IQWiG); Dillenburger Str. 27 Cologne Germany 51105