How does cryosurgery cause injury?

Freezing causes intracellular and extracellular ice crystals to form, and the subsequent vascular stasis causes tissue anoxia and necrosis. The most efficient technique employs a rapid freeze and slow thawing. Multiple short freezes produce more damage than a long freeze. Different cell types have variable susceptibility to the effects of freezing, with melanocytes being damaged at a much higher temperature than keratinocytes (−5° C versus −50° C). This differential freezing has implications for the treatment of melanocytic lesions, as well as the use of cryosurgery in patients with darkly pigmented skin.

Gage AA, Baust J: Mechanisms of tissue injury in cryosurgery, Cryobiology 37:171–186, 1998.