Cryosurgery consists of the destruction of biological tissue by freezing. It is a technique widely used in our daily medical practice in the consultation, simple to perform, effective and with good cosmetic results if done properly. The therapeutic effect of col don human tissue has been known since the 19th century, with liquid nitrogen being the most widely used agent in dermatological consultations to carry out this technique. Because it evaporates when exposed to air, liquid nitrogen needs to be stored in cylinders or bottles.
Whats is the mechanism of action of cryosurgery?
When cold is applied, tissue is damaged due to intracellular and extracellular ice formation, with destruction of cell membranes, in addition to causing changes in circulation caused b freeze/ thaw cycles.
In practice, we apply the liquid nitrogen in spray (with different caliber applicators) and the frostbite on the skin begins immediately, observing a whitish discoloration that spreads peripherally from the point of contact.
The Depth of frostbite can be increased by applying pressure to the skin or by prolonging the duration of the procedure.
What injuries can be treated by cryosurgery?
Superficial skin injuries, whether benign or malignant, are usually treated. On many occasions, we use cryotherapy as a step prior to shaving the injury, since on the one hand, it provides light instant local anesthesia and, on the other hand, the fact of freezing the tissue facilitates the cutting of it.
Some skin injuries tributary to cryotherapy treatment are the following:
- Benign injuries: Seborrheic keratosis, fibroids, viral vulgar warts, flat warts, solar lentigos, condylomas, molluscum contagiosum, among others.
- Malignant injuries: actinic keratosis, superficial carcinomas.
What cures have to be done after the procedure?
Generally, the patient is recommended to do normal hygiene of the treated area on the same day after the procedure and to apply a topical antiseptic (iodine or alcohol) daily to disinfect and help keep the wound dry and scab formation. The scab will take 2-3 weeks to fall, leaving a more vulnerable area of skin, so it is very important to apply sun protection during the days and months after the technique is performed to avoid the development of little cosmetic spots (hyperpigmentation).
What complications can be expected?
Although it is a fairly safe technique, there are a number of risks, or complications that should be known, as well as how to avoid them.
Treatment safety begins with careful selection of the patient and the injury to be treated.
The appearance of possible is mainly related to the duration of the procedure and the patients skin type.
In general, the dermal collagen network is not significantly altered if the total duration of the freeze pulses lasts less than 30 seconds; if the duration is longer, there is a risk of developing scars (anthropic and hypertrophic).
The most common complications that can occur after cryotheraphy are:
- Pain: The patient usually reports mild-moderate pain during frostbite and a few minutes later. It is generally transient and does not require analgesia.
- Imflammation and Edema: Immediately after frostbite there is a swelling and redness (erythema) of the treated área that can last several hours (up to 1-2 days). It is generally transitory drying or astringent solutions can be applied to reduce inflammation and associated local discomfort.
- Formation of vesicles/blisters: they can appear within a few hours and, in the case of large, tense blisters with a large amount of liquid, they can be punctured to extract the liquid and thus facilitate its drying and alleviate the local nuisance.
- Hypo or hyperpigmentation: it is recommended to use adequate sun protection to avoid hyperpigmentaion above all.
Most severe reactions are more common in thinner skin areas (eyelids, back hands, temple), or those that have cumulative sun damage.
Blistering after cryotherapy
- Cranwell WC, Sinclair R. Optimising cryosurgery technique. Aust Fam Physician 2017;46(5):270-274.
- B Rubinsky. Cryosurgery. Annu Rev Biomed Eng 2000;2:157-87.
- Michael E Farhangian, Alyson Snyder, Karen E Huang, Laura Doerfler, William W Huang, Steven R Feldman. Cutaneous cryosurgery in the United States. J Dermatolog Treat 2016;27(1):91-4.