[Results and prognosis after highly selective vagotomy in the light of the mathematical theory of approximate sets].

Information system for 122 patients with peptic ulcer, who underwent highly selective vagotomy within 5 and 13 years earlier has been analysed with the use of technique based on the approximate sets theory. Cause-effect relationship between data describing the analysed patients before surgery and remote result of therapy (expressed in a 4-score Visick's scale) have been sought. Using a technique of the approximate sets, information system has been described from 11 to 5 significant and necessary preoperative data most closely related with the result of therapy. Models of the typical representatives of results classes have been constructed with the use of a/m data. Then, a decision algorithm has been made. Such an algorithm represents cause-effect relationship between significant data and the result of treatment. Models and decision algorithm for the favourable results of the treatment (I and II class in Visick's scale) constituted a base for the verification of indications to the highly selective vagotomy and construction of data base for computer-assisted system of the treatment of peptic ulcers with the highly selective vagotomy.