What is Cryosurgery?
Cryosurgery or cryotherapy is the application of extreme cold to destroy abnormal, disease, or unwanted living tissue like a wart or a cyst. Cryosurgery is used to treat a number of diseases and disorders, especially skin conditions. This treatment allows growths to be removed without actual cutting. The application of intense cold will result in the death of the targeted tissue and the numbing of the surrounding sensory nerves, reducing pain and discomfort.
In animals, the technique particularly helpful to treat tumors and growths in locations where conventional surgery would be difficult or impossible, such as certain tumors of the mouth. Examples include the removal of highly irritant tumors or lesions which the animal is constantly biting, licking or scratching. The technique is sometimes also used for the removal of aberrant or extra eyelashes (distichiasis). It also provides a solution for tumors or infected itchy lesions in elderly patients considered high risk for general anesthesia and prolonged surgical procedures.
How is cryotherapy performed?
Cryotherapy uses freezing temperatures to destroy cells in the target tissues. Most of the body’s cells are comprised of about 70% water. When applied to tissue ice crystals form inside the cells, causing them to tear and rupture. Additional cellular and tissue damage occurs when blood vessels supplying the diseased tissue freeze.
The most common method of performing cryosurgery is with liquid nitrogen. The newer technology allows doctors excellent control of the amount of tissue that is frozen and helps minimize complications. Hair needs to be clipped from around the lesion, but surgical sterility is not necessary. The surgeon is most likely to use liquid nitrogen contained in a special device with a probe attached to the end. The probe is placed against the lesion and a trigger pulled, which super chills the tip of the probe and anything it is in contact with. The tip is held in place until a freeze halo a few millimeters wide develops around the lump. Then the trigger is released and the surgeon waits for the tip to thaw to release it from the tissue. This freeze-thaw cycle is repeated two to three times.
Is the technique painful?
With cryotherapy, the treatment is almost always carried out with local anesthesia. This may be either simply ice, local anesthetic with sedation, or if needed like on an eye, a general anesthetic. Because of the inherent analgesic/anesthetic effect of the procedure, if future cryotherapy is necessary at the same location, it may be possible to perform it without the use of any further anesthetics. The intense cold also kills bacteria and other germs. This is particularly advantageous when dealing with infected tissues
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 foul odor from the affected tissues. Despite the unpleasant appearance, there is no discomfort because of the temporary anesthetic effect on nerve endings. The patient is usually much happier than before. In more advanced or serious conditions, multiple cryotherapy treatments may be required
How effective is cryosurgery?
In many cases, it can be curative depending on the condition and the site. This procedure has a high success rate. Small warts and small skin tumors are usually cured with just one cryotherapy session. Tumors in the mouth often go into remission after one treatment and cause no further trouble. It should be appreciated that the lesions often take around 2 weeks to die and drop off. During this time the lump is liable to swell, and can often look infected and sore. This is nothing to worry about, but a natural process in which the body sloughs off dead tissue. Occasionally, a single cycle of three freeze-thaws is not sufficient to get rid of a lesion, in which case it might need to be repeated two to three weeks after the original cycle. During the recovery period, the area must be protected from licking or chewing but is best left open to the air. Therefore expect the dog to wear an E-collar.
The success of cryosurgery depends on choosing the correct type of lump to use it on. It is unlikely to be effective for large lumps (above 11 cm) because freezing cannot penetrate right to the base of the lump. However, for skin tags, warts, or small superficial tumors it is a good choice. Another plus of cryosurgery is that the frozen lesion eventually dies off and ‘shells out’, meaning it falls off. This means there are no painful incisions to be cared for or sutures where there is a risk of the dog pulling them out with the associated wound breakdown.
Dog Cryosurgery Considerations
Cryosurgery is a relatively safe procedure which is used in high-risk patients, because of its lack of complications. One of the biggest considerations is that the procedure may need to be repeated if it wasn’t successful after one cycle. In addition, the dead tissue can look and smell unpleasant. Many of the conditions for which the use of cryosurgery is appropriate do not have a direct cause, therefore, it is impossible to prevent them. For the dog that has had one skin lump removed, it can’t be ruled out that he won’t grow a new one at a different site in the future.
For more information on Cryotherapy or to book an appointment at Meadowlands Veterinary Hospital to have your dog, cat or exotic pet examined for cryotherapy call us at 201-646-2008 or visit us at http://www.meadowlandsvethospital.com