Cryosurgery

Cryogenic chamber, cryosurgery, ice pack, therapeutic hypothermia.

Cryotherapy is the application of cold temperatures to part or all of the body. The term encompasses a broad variety of practices.

Cryotherapy, referring to the ablation of tissue by local induction of extremely cold temperatures, has its earliest roots in 19th Century London, where a physician applied ice-salt mixtures to cancers of the breast and cervix. The 1966 invention of probes cooled by liquid nitrogen in closed circulation was the beginning of modern cryotherapy. One of the first applications of this new technology was the ablation (elimination or removal) of benign prostatic hyperplastic tissue through the urethra, followed shortly by the treatment of prostate cancer via an open perineal approach.

There are several types cryotherapy, each with varying techniques for various treatments. Cryotherapy is often used in sports medicine as the application of ice packs to sore muscles or bruised areas. Cryosurgery, or the use of very localized and targeted application of cold temperatures to destroy diseased tissues, is most often used to remove warts and a variety of cancers.

Therapeutic hypothermia is often used after an adverse medical event, where the affected area of the body is submerged in cold but not freezing temperatures. The technique is under investigation as a means of preventing damage to heart and brain tissue after oxygen deprivation. A fourth treatment, cryogenic chamber therapy, involves spending two or three minutes in what is known as a cryogenic chamber; this extreme technique is used by individuals experiencing chronic pain - often due to rheumatic complaints.

The mechanism of action of cryotherapy can be divided into three phases, heat transfer, cell injury, and inflammation. The mechanism by which cryotherapy destroys the targeted cells is the quick transfer of heat from the skin. Cell injury occurs during the thaw, after the cell is frozen. Because of the hyperosmotic intracellular conditions, ice crystals do not form until -5?C to -10?C. The transformation of water to ice concentrates the extracellular solutes and results in an osmotic gradient across the cell membrane, causing further damage. Rapid freezing and slow thawing maximize tissue damage. The last response to cryotherapy is inflammation, which is usually observed as erythema and edema. Inflammation is the response to cell death and helps in local cell destruction. A thorough cryotherapy treatment causes basement membrane separation, which may result in blister formation.

Cryotherapy is an accepted and commonly used practice in sports medicine because it has been shown to reduce the inflammation associated with many athletic injuries. The use of cryotherapy in sports medicine can be as simple as applying an ice pack to a swollen area of the body. It can also be administered with ice massages or cold whirlpools. The cooling of the affected area slows the release of chemicals that cause inflammation and swelling. The cold temperatures also reduce the ability of nerve endings to conduct pain signals.

Cryosurgery is a common in-office medical procedure used to treat a wide variety of conditions, ranging from a sprained ankle to prostate cancer, and including a variety of benign or malignant lesions. It can usually be performed in the office because it is minimally invasive and can be as simple as the application of an ice pack. The American Medical Association approves of cryosurgery, so long as a qualified, licensed, and trained practitioner is consulted.

The medical community has taken increasing interest in the use of therapeutic hypothermia after significant medical emergencies. Research has included studies on newborns experiencing asphyxia at birth and in adults with cardiac arrest. This research has concluded that only a particular subset of individuals benefit from therapeutic hypothermia. For example, there seems to be good evidence to recommend the use of induced mild hypothermia in comatose survivors of out of hospital cardiac arrest caused by ventricular fibrillation. This subset of patients had the best level of evidence regarding the efficacy of this treatment. Many in-hospital cardiac arrests have noncardiac causes, andbecause the use of therapeutic hypothermia has not been studiedto a significant extent in this population, its relative risksand benefits are unknown. It is possible, however, that patientswho remain comatose after an in-hospital arrest of cardiac etiologywill also benefit from therapeutic hypothermia. The medical community is as of yet unable to determine why some patients benefit more than others. Until further data are available, therapeutic hypothermia shouldnot be used for patients with severe cardiogenic shock or life-threateningarrhythmias, pregnant patients, or patients with primary coagulopathy.

Cryogenic chamber therapy is a controversial treatment. Patients report a significant decrease in their pain for up to six hours after treatment. However, exposing the body to such temperatures carries certain risks, and more research is needed in this area.

This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

American Medical Association. 30 May 2006.

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Metzger D, Zwingmann C, Protz W, et al. Whole-body cryotherapy in rehabilitation of patients with rheumatoid diseases--pilot study. Rehabilitation (Stuttg). 2000 Apr;39(2):93-100.

Nolan JP, Morley PT, Vanden Hoek TL, et al. Therapeutic hypothermia after cardiac arrest: an advisory statement by the advanced life support task force of the International Liaison Committee on Resuscitation. Circulation. 2003 Jul 8;108(1):118-21.

Wilk K, Macrina L, Reinhold M, et al. Rehabilitation following thermal-assisted capsular shrinkage of the glenohumeral joint: current concepts. J Orthop Sports Phys Ther. 2002 Jun;32(6):268-92.

Cryotherapy in sports medicine: This type of cryotherapy is often the simplest, involving the application of an ice pack to a swollen injury. It is often done at home, and should be started within 48 hours of the injury. Most experts recommend applying the ice pack for a maximum of twenty minutes at a time.

Cryosurgery: Cryosurgery can be used to treat warts, hemorrhoids, skin lesions, and a variety of cancers, by ablating the affected tissue. The patient usually does not have to prepare for the surgery in any way; this in-office procedure is usually minimally invasive. The healthcare provider applies the cold temperature to the affected area by using a probe like tool. The probe contains a very cold gas, like nitrous oxide, which makes the tip of the probe very cold. Depending on the area being treated, the patient may or may not feel a cold sensation. The amount of time the probe needs to touch the affected area depends on the size and type of lesion and the type of gas being used. After the procedure, a blister may form which will later turn into a scab.

Therapeutic hypothermia: This type of therapy is used for an unconscious patient who has spontaneous circulation after suffering an out of hospital heart attack. In the hospital, the patient is cooledto 32?C to 34?C for 12 to 24 hours in hopes to minimize damage to brain tissue and improve functional recovery.

Cryogenic chamber therapy: The cryogenic chamber is cooled to -110?C. The patient wears no more than a small bathing suit, in addition to thick socks, gloves, and mouth and ear protection. Generally there is a pre-chamber, which is cooled to -60?C . The patient spends 30 seconds here before moving into the main chamber for two to three minutes. There is a window between the chamber and the outside operator, allowing visual contact to be maintained at all times. There is a two-way intercom as well. During treatment the average skin temperature drops 12?C, while the coldest temperature can be 5?C. The core body temperature remains unchanged during the treatment, while after it, it may drop slightly.

After emerging from the chamber patients report a pleasant warm feeling throughout the whole body. All joints move more fluidly, they feel happy, strong, and full of energy; this initial positive effect may last up to six hours. The immediate effect of skin cooling and analgesia lasts for five minutes, but the release of endorphins can have a lasting effect, where the pains and signs of inflammation as found in blood tests remain suppressed for weeks. Advocates claim that it takes 20 to 50 sessions to create long-term benefits. This type of cryotherapy is used to treat fibromyalgia, amongst other disorders. It is also used as an ergogenic aid by athletes, as it is claimed to give them power.