cryosurgery, bloodless surgical technique using a supercooled probe to destroy diseased or superfluous tissue. Liquid nitrogen circulating through the instrument cools it to temperatures as low as -196°C; (-321°F;). Tissue destroyed on contact with the probe is removed by phagocytic white blood corpuscles in a natural bodily process. The method has proved successful in removing warts, tumors, hemorrhoids, and in treating certain brain disorders. It is especially useful in ophthalmology, where it is used to reattach detached retinas and to correct other eye problems.