CRYOSURGERY (Cryotherapy)

What is Cryosurgery?

Cryosurgery is sophisticated frostbite. Natural, severe frostbite will affect the blood supply particularly to extremities, such as ears, fingers and toes. This will result in death of the part which is subsequently lost.

Cryosurgery, (cryotherapy) employs the same principal. Cryotherapy is a better description of the procedure since surgery is usually associated with cutting and in this case the treatment (therapy) does not, with a few exceptions, involve actual cutting.

Cryotherapy has been around for about a hundred years. The technique is not new. The principles are that the application of intense cold will result in the death of the target tissue and the numbing of surrounding sensory nerves so that pain and discomfort are reduced. In man this aspect is often employed for the treatment of patients with intractable cancer to reduce pain and discomfort by temporarily numbing sensory nerves. In animals the technique is employed to treat tumors where conventional surgery would be difficult or impossible, e.g. some tumors of the mouth, or where the analgesic/anesthetic properties of the technique would be useful. Examples include the removal of highly irritant tumors or lesions which the animal is constantly biting, licking or scratching, tumors or infected itchy lesions in elderly patients considered unsuitable for general anesthesia and prolonged surgical techniques where a long anesthetic may present unacceptable risks.

Why sophisticated frostbite?

It is sophisticated frostbite because a source of cold (e.g. liquid nitrogen with a boiling point of approximately -180C) or sometimes warmer cryogens, like dry ice (carbon dioxide) or nitrous oxide are used via sophisticated apparatus to deliver the source of cold to the target tissue and at the same time to spare surrounding tissue.

Is the technique painful?

Anyone who has been frost bitten will confirm that the actual freezing insult is painful. You know how painful it is when your fingers get cold in winter, yet snow and ice are relative warm cryogens. After all, it does not usually result in frostbite. With cryotherapy the actual freezing insult, which could be painful, is always carried out under anesthesia This may be either a local anesthetic with sedation or more usually a general anesthetic Because of the inherent analgesic/ anesthetic effect of the procedure, if subsequent freezing sessions are necessary, these can sometimes take place without the use of any further anesthetics and are painless.

The intense cold kills bacteria and other germs. One of the major uses of the technique is for the treatment of anal furunculosis, a condition affecting the anal region of some dogs particularly the German Shepherd Dog.

Once freezing has occurred the tissue slowly dies and falls away. In some moist sites such as the mouth and the anus the tissue may liquefy and look green and gangrenous. Usually all that is necessary is gentle bathing of the area to remove as much of the dead and sloughing tissue as necessary. There is sometimes a smell. However despite the appearance there is no discomfort because of the temporary anesthetic effect on nerve endings. The patient is usually very much happier than before. In cases where there is the need for extensive tissue destruction sometimes more than one session is necessary.

Is it curative?

In many cases it can be curative depending on the condition and the site. Anal furunculosis lesions respond in about 80% of cases.

The technique is also used for the removal of aberrant or extra eyelashes (distichiasis) and in these is almost invariably curative although other lashes may grow.

Small warts and small skin tumors are usually cured with just one cryo session.

Tumors in the mouth often go into remission after one freezing and cause no further trouble.

Is it beneficial?

Because of the anesthetic effect your pet will benefit from the technique if the lesion causes discomfort even if a cure is not possible.

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