Cryoprobe

Cryosurgery (with ''cryo'' from the Ancient Greek ) is the use of extreme cold in surgery to destroy abnormal or diseased tissue; thus, it is the surgical application of cryoablation.

Cryosurgery has been historically used to treat a number of diseases and disorders, especially a variety of benign and malignant skin conditions.

History

In 1841, English physician James Arnott described therapeutic applications of extremely cold temperatures, namely a mixture of crushed ice and salt applied locally (to skin or mucous membrane). He theorized his technique was capable of "arresting the accompanying inflammation, and perhaps destroying the vitality of the cancer cell." His works were the first to hypothesize that extreme cold could be used to selectively damage or destroy harmful tissue.

Uses

Warts, moles, skin tags, solar keratoses, molluscum, Morton's neuroma and small skin cancers are candidates for cryosurgical treatment. Several internal disorders are also treated with cryosurgery, including liver cancer, prostate cancer, lung cancer, oral cancers, cervical disorders and, more commonly in the past, hemorrhoids. Soft tissue conditions such as plantar fasciitis (jogger's heel) and fibroma (benign excrescence of connective tissue) can be treated with cryosurgery.

Cryosurgery works by taking advantage of the destructive force of freezing temperatures on cells. When their temperature sinks beyond a certain level ice crystals begin forming inside the cells and, because of their lower density, eventually tear apart those cells. Further harm to malignant growth will result once the blood vessels supplying the affected tissue begin to freeze.

Cryosurgery is used to treat a variety of benign skin lesions including:
* Acne
* Dermatofibroma
* Hemangioma
* Keloid (hypertrophic scar)
* Molluscum contagiosum
* Myxoid cyst
* Pyogenic granuloma
* Seborrheic keratoses
* Skin tags
* Warts (including anogenital warts)

Cryosurgery may also be used to treat low risk skin cancers such as basal cell carcinoma and squamous cell carcinoma but a biopsy should be obtained first to confirm the diagnosis, determine the depth of invasion and characterize other high risk histologic features.

Method

Liquid nitrogen

A common method of freezing lesions is by using liquid nitrogen as the cryogen. The liquid nitrogen may be applied to lesions using a variety of methods, such as dipping a cotton or synthetic material tipped applicator in liquid nitrogen and then directly applying the cryogen onto the lesion. The liquid nitrogen can also be sprayed onto the lesion using a spray canister. The spray canister may utilize a variety of nozzles for different spray patterns. A cryoprobe, which is a metal applicator that has been cooled using liquid nitrogen, can also be directly applied onto lesions.

Carbon dioxide

Carbon dioxide is also available as a spray and is used to treat a variety of benign spots. Less frequently, doctors use carbon dioxide "snow" formed into a cylinder or mixed with acetone to form a slush that is applied directly to the treated tissue.

Argon

Recent advances in technology have allowed for the use of argon gas to drive ice formation using a principle known as the Joule-Thomson effect. This gives physicians excellent control of the ice and minimizes complications using ultra-thin 17 gauge cryoneedles.

Freeze sprays

A mixture of dimethyl ether and propane is used in some "freeze spray" preparations such as Dr. Scholl's Freeze Away. The mixture is stored in an aerosol spray type container at room temperature and drops to when dispensed. The mixture is often dispensed into a straw with a cotton-tipped swab. Similar products may use tetrafluoroethane