[The minimal freezing temperature for a necrosis of the epidermis and the influence of cryoprotective agents (author's transl)].

The sensitiveness to cold of the epidermis (cold threshold) is determined on the auricular skin of 24 rabbits, using freezing temperatures of -10, -15, -20, -25, -30, and -40 degrees C and a freezing time of 30 sec. The experiments are performed with and without application of cryoprotective agents (DMSO, glycerol and aethanol in a 10% solution) before cryosurgery. Only at -20 degrees C a necrosis of the epidermis is seen whereas after application of cryoprotective agents before freezing a necrosis of the epidermis first appears at -30 degrees C. Following these experiments clinically it might be possible to protect the epidermis in the periphery of the freezing area up to a certain degree with the use of cryoprotective agents, so that a topographically more concentrated epidermis-necrosis and therefore a limitation of the cryoeffect to the epidermis to a certain degree could be possible.