Technique of cryotherapy

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Technique of Cryotherapy

Elisabeth Dachow-Siwiec, MD

From the Department of Dermatology, Warsaw School of Meditine, Warsaw, Poland

Cryotherapy is currently one of the most frequently used methods in the treatment of warts. Among the cryogenic materials used in medicine at present (solid COz -78.5”C, liquid nitrous oxide -89.5%, etc.), liquid nitrogen proved to be the most useful because of its low temperature (-195.6%), easy availability from medical and commercial sources, low cost, and safety in use-it is not flammable and is inactive chemically.

Techniaue Liquid nitrogen evaporates very quickly; therefore, it is stored in special metal Dewar containers with small openings. Its durability period is limited to a few days. Usually, a number of patients may be treated with the contents of a one-liter container of liquid nitrogen. Specially constructed apparatus is used for treating patients, with changeable nozzles adapted to the shape and diameter of the skin lesion. This apparatus is currently widely employed in the treatment of skin cancers. It is also possible to use a more simple method, using a wooden stick with cotton wound around the tip. The cotton tip is formed in a thin or thick shape, depending on the size of the skin lesion. The prepared cotton tip is dipped in liquid nitrogen, which is kept in a Thermos bottle or in a Styrofoam container. The tip is then applied directly to the lesion. The diameter of the metal or cotton tip cryoapplicator should be, more or less, the same as the diameter of the lesion. The entire lesion and a surrounding area of 2-3 cm should be frozen. The time of freezing varies. It depends on the type of wart, diameter, depth, and location of the lesion. It may vary from a few seconds (for example, verrucae planae) to about one minute (for example, verrucae plantares). I have found that, during treatment, the patient may feel no pain or, at the most, a burning and pricking sensation. Directly after the treatment, during the period of thawing, the patient usually feels a more intensive burning sensation or a light pain, lasting from several seconds to one or two minutes. Because of this, I recommend cryotherapy especially for children 185

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who, in my experience, endure the operation quietly, feeling the discomfort or pain only after treatment. The pain, however, varies in intensity with individual patients and is related to the pain threshold and to the type of wart. For exam pie, the freezing of periungual verrucae and subungual verrucae is more painful than the freezing of common warts in other places. Usually. directly after the operation, the treated area first becomes pale and then turns red. After a few minutes, a swelling occurs ahich may last several hours. Later, serous or blood-filled blisters will form. We have observed a correlation between the forming of the blister and the success of the treatment, whereas Bunney’ believes that warts should be frozen without blistering. We freeze the base of the warts solidly (Fig. 1). with a margin of several millimeters, similar to the procedure used b> Lubritz.‘since we have noticed that without blistering the treatment had to be repeated. The blister should cover the whole lesion. with a several-millimeter margin around it: however, it should not extend significantl! beyond the frozen area. Should a rapid increase in effusion occur. the skin should be pierced with a sterile needle to permit the serous matter to escape. The roof of the blister should not be removed. since this may lead to infection of the uncovered area. The blister covering serves as isolation against such an eventuality and eliminates the need for a bandage. If the above procedure is followed, infection after cryosurgery is rare. After a few or more days, the blister dries up and a scab forms, which lasts one or two weeks. By this method the lesion is healed, on an average, within three weeks. The period of healing, however, depends to a great degree on the type of lesion since, for example. condylomata acuminata of small diameter or plane warts may be healed after one week. Common Warts These warts by cryotherapy.

Clinics in Dermatology

may be treated It is necessary

successfully to freeze the

Lrhole lesion and a small, up to 2-mm, rim around it. In most cases, the lesions (Fig. 2) are healed after a single freezing (Fig. 3). If there is a very important hyperkeratosis. 10% salicylic ointment or a leukoplast should be applied for several days before treatment to the wart. A wart, prepared in this manner, easily absorbs the liquid nitrogen and one treatment usually removes it. Warts under and around fingernails are more resistant to freezing, especially so, if they are long-standing, deep, and hyperkeratotic. Several days before treatment they should be softened, as described above. Usually. these warts are frozen with cottontipped sticks. The use of contact cryoprobes is not recommended since it is impossible to maintain an even contact of the applicator with the surface of these warts. Sometimes it is necessary to repeat the freezing several times to achieve complete removal of the lesion. This is due to the pain suffered by the patients during and after freezing, which makes it necessary to stop the treatment prematurely, thereby reducing its effectiveness. It is our experience that quicker treatment is achieved by anesthetizing the fingers by the Obersta method through the use of a lidoCaine solution. Within a few minutes after the anesthetizing, it is possible to freeze the warts sufficiently deep, without interrupting the treatment. With such a solid freezing, the warts disappear after one treatment. The fingernail usually remains undamaged.

Plantar Warts of Myrmecia Type Attention should begiven to the removal of the hyperkeratosis before treatment, previously softening it with the salicylic ointment. The recurrence of the lesion is most often due to the incomplete removal of the horny layer, which makes it necessary to refreeze the same place several times. Plantar warts should be frozen within the involved skin (about 5 mm in diameter, especially for some long-standing warts). In the case of unusually resistant warts, a cycle of

October-December Volume 3 Number 4

1985 Cryotherapy

FIG. 1. (right). Periungual of liquid nitrogen.

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warts frozen with the use

FIG. 2. Warts before treatment with liquid nitrogen: A (left, below). Common warts. B (left, far below). Periungual warts. FIG. 3.The same patient as in Fig. 2: A (right, below). Two months after treatment with liquid nitrogen. B (right, far below). Three months after treatment.

freezing-thawing-freezing should be followed during a single treatment.3 Care should be taken in treating elderly people. Cryotherapy in those patients may produce ulceration with a long period of healing. Single plantar warts may be frozen with a cryoprobe, or with a stick having a tightly wound cotton tip, both with the application of pressure. Mosaic Watts All of the warts

should

be spray-frozen

superficially; however, sufficiently to produce blisters. Widely spread-out lesions should be frozen by areas every three weeks. Plane (Flat) Warts Plane warts should be frozen by the spray method, for a few seconds, very superficially, in order to bring out only an inflammatory reaction but not to produce blisters. and subsequent scars. Such a procedure is particularly indicated for plane warts on the face. In our experience, in 20% of the patients, heal-

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ing is achieved after the first treatment. Terre” maintains that plane warts may be treated by using a broad, rounded applicator which is moved over the warts area. Our experience shows that the best cosmetic results are obtained by the spray method. Condylomata Acuminata This type of wart is very responsive to cryotherapy. Numerous lesions on the male foreskin should be spray-frozen progressively, freezing a limited surface every few days. Avoid attempting to spray all lesions during a single procedure, since this leads to swelling and phimosis. The best results were obtained in the area of the anus. Warts in this localization disappeared quickly without any recurrence. The period of freezing lasts from a few seconds for small lesions to 20-30 seconds for the large ones. Condylomata acuminata, especially if small, disappear more rapidly than ordinary warts. Therefore, the patient should be reexamined after 7 to 14 days. Complications of Treatment In occasional patients, there may be a fever lasting two to three days. We observed, from

time to time, a slight discoloring after several weeks. Hypertrophic scars appeared very rarely and only in persons with a tendency to keloids. Nix’ reported two cases of neuropathy after cryotherapy of warts located on the lateral aspect of the fingers. In several cases, we noticed some disturbance of sensitivity after the removal of the warts on the lateral side of the fingers. All cases of neuropathy. however, were reversible within a period of several weeks to several months. As stated above, care should be taken in treating warts in elderly people, especially those located on the lower limbs, since the period of healing may be prolonged by several weeks. Similarly, care should also be taken in treating young people with vascular disturbances in the extremities. References 1. RunneyMH. Viral warts: their biology and treatment. Oxford: Oxford University

Press, 1982:47-55.

2. Lubritz RI,. Cryosurgery of benign and premalignant cutaneous lesions. In: Zacarian SA. ed. Cryosurgical advances in dermatology and tumors of the head and neck. Springfield, IL: Charles C Thomas, 1977:500-529. 3. Zacarian SA. The observation of freeze-thaw cycles upon cancer-cell suspension. J Dermatol Surg Oncol. 19773: 173-174. 4. Torre D. Cryosurgery in dermatology. In: Von Loden H, Cahan WG, eds. Cryogenics in surgery. Flushing, NY: Medical Examination Publishers, 1971:500-529. 6. Nix TW .Jr. Liquid nitrogen neuropathy. 1965;92:185-188.

Address for correspondence: Elisabeth Dachow-Siwiec, Koszykowa 82a, 02-008 Warsaw, Poland.

MD, Klinika Dermatologiczna

Arch Dermatol.

A.M., ul.