[Guidelines in surgery of the liver and bile ducts]

The surgery of biliary ducts and malignant liver tumors is formulated illustratively in guidelines in order to assist the physician as well as the uninformed patient in their orientation concerning diagnostic, therapeutic and prognostic questions. Special attention is paid to diagnostics, which is based on both rational and empirical verified arguments. Moreover, the examples presented in this study show that guidelines can only be formulated if extensive verified knowledge exists; for rare diseases and those about which little is yet known guidelines cannot (yet) be formulated.