[Choice of working temperatures for cryo-instruments used for local destruction of biological tissue]

When utilizing low temperatures for irreversible destruction of affected biological tissues it is important that one should have a clear idea as to the boundary of necrotic alterations. The correlation between the depth of necrosis and that of freezing, the rate of the tissue congelation, the period of cryogenic action, the temperature of the cryoinstrument and its structural shape, all these factors are analytically interrelated and this enables it to establish optimal performance characteristics in congelation of different tissues. In most cases satisfactory performance characteristics in freezing biological tissues can be achieved by using liquid nitrogen.