The molecular basis of cryosurgery

generally defined as arising from two major mechanisms. These are the direct injury to cells caused by ice crystal formation and the microcirculatory failure which occurs in the thawing period [2]. The relative importance of these two mechanisms has long been debated, but both are clearly major effects. Ice-crystal formation removes water from the biological system, which produces a host of deleterious effects. Intracellular ice is particularly lethal for cells. Cells closely packed in a tissue may sustain damage from ice crystals by purely mechanical means, as from the shearing forces of the crystals. The vascular effect, i.e. the microcirculatory failure that follows thawing, is evident in any experiments in vivo . The loss of blood supply deprives the cells of any chance of survival. The importance of this mechanism of injury, featuring vascular stasis in the thawed tissue, has long been stressed, including in recent investigations [3]. Nevertheless, from the molecular perspective, the most important advance in basic research related to cryosurgery is the recognition that apoptosis is a mechanism of cell death after cold injury [4].