The cryobiological basis for cryosurgery.

This paper discusses two important biological factors contributing to the death of cells within any region that is frozen cryosurgically. The first factor is the relationship between cell death and the thermal history experienced by each cell. Freezing with a single probe as usually done cannot provide sufficiently uniform conditions of cooling and warming to ensure widespread cell death. This situation can be improved by cycling a single probe at subzero temperatures or by the use of a multiple probe. The second factor is that of possible immunological responses induced by cryosurgical freezing. Improvements in understanding of biological implications of low temperatures in cryosurgery will aid the practical usefulness of these techniques.