Cryosurgery

Cryosurgery is a therapeutic technique that involves the localized application of extreme cold to destroy abnormal or diseased tissue. Its name derives from the Greek word cryo, meaning “icy cold.” The main diseases and disorders that are treated by cryosurgery are often connected with skin. Cryosurgery can be used to treat warts, moles, skin tags, solar keratoses, and small skin cancers. In recent years, cryosurgery has also been used for treating some internal disorders, including cancers such as liver cancer, prostate cancer, and some cervical cancers, as well as for the control of gynecologic and urologic tumors, the elimination of hemorrhoids, and other conditions that involve diseased tissues. Although it has been found to be effective in some circumstances, it can only be used against localized diseases; that is, when the cancer has not spread.

From the 1950s, developments were made in cryopreservation, which was used to store specific cells and tissues at very low temperatures. Soon, it was realized that particular cells and tissues could also be destroyed or permanently damaged owing to the method of freezing or the destructive forces on cells of the freezing temperature. Although this was originally concerned with tissue or cells away from the human body, it was only a matter of time when methods were developed to treat people with cryosurgery.

It has also been found that freezing can destroy cells and tissue by triggering an immune response, which can lead to the release of intercellular proteins that can attract natural antibodies, which in turn can be used to destroy diseased cells. These techniques were developed and improved on in 1961 by the U.S. neurosurgeon Irving Cooper, who used liquid nitrogen to destroy brain tumors in the first efficient cryosurgical system applied to internal tissues.

[Page 462]At its most basic, cryosurgery involves damaging blood vessels that supply diseased tissue by freezing them. This then allows parts of the body to be treated. The main technique involves the use of liquid nitrogen, which can be sprayed in very small amounts onto the diseased tissue using a tube called a cryoprobe or simply dabbed on with a cotton swab. For less severe problems, some doctors have used carbon dioxide rather than nitrogen. As cryosurgery on the skin is minimally invasive, involves minimal pain and/or scarring, and is cheap, it is being used more and more; however, there has been new research into the possibility of damage to nerve tissue.