[Surgical risk: some problems and methods of analysis]

A decision made by a surgeon in a risk situation differs basically from his action under condition of a necessity (extreme necessity). If the former situation is characterized by the existence of an alternative and a choice (the possibility of avoiding the infliction of harm to the patient), in the latter situation of extreme necessity (when there is no choice), in contrast, such a possibility is absent--the harm is inevitable. The property of the risk--the discrepancy between the objectively existing risk situation and its subjective evaluation--compels the surgeons to evaluate it mainly on the basis of their own experience--on the level of opinion. At present attempts are made to determine the value of the operative risk in the form of a matrix, estimation expressions, "tree of decisions", score counting and mathematical-statistical methods. An effective, sufficiently simple classification of operative risk criteria may promote the solution of an adequate scientific evaluation of the degree of the operative risk. The problem of the operative risk may be solved only on the basis of an interdisciplinary approach.