Warts, actinic keratoses, molluscum contagiosum, small basal cell carcinomas, condyloma acuminata and more, the list of skin conditions that can be easily and successfully treated with cryotherapy is quite extensive. Cryosurgery is a surgical technique that uses controlled freezing to deliberately destroy diseased tissue.
Cryosurgery most often uses liquid nitrogen as the freezing medium, though nitrous oxide may be used as well. The cryotherapy surgical method is a much preferred alternative to surgical excision of skin lesions for many skin conditions for the following reasons.
Benefits of cryosurgery for skin lesions:
-Freezing produces minimal pain
-Results in little to no scar formation
-Takes less time than conventional surgery
-Often allows patients to avoid injections of local anesthetics, so needles can be avoided
-Preoperative skin preparation (sterile technique) is not required
-No significant post-procedure care is required
-Postoperative infection is rare
-No significant change in activity is required after freezing, patients may bathe, swim, etc.
-Cryosurgery is cost effective
-Multiple lesions can be done in one office visit
However, there are a few disadvantages to cryosurgery of skin conditions. These disadvantages may limit the use of cryosurgery in some individuals, particularly darker skinned individuals as described below.
Additionally, there are certain skin lesions which should not be treated with liquid nitrogen or other freezing techniques. Cryosurgery does not allow for the gathering of tissue samples to send for pathological examination. Therefore, there is no way to know whether the entire squamous cell carcinoma or melanoma has been destroyed when treated with cryosurgery. These lesions are best removed with surgical excision or Mohs surgery.
Disadvantages of cryosurgery for skin lesions:
Freezing the skin, even with brief partial-thickness freeze technique, will destroy some pigmented melanocytes. Therefore, when the lesion heals, it will be a bit lighter in color than the surrounding skin.
The lack of pigment producing melanocytes within healed cryosurgical lesions may also make the lesion more susceptible to sunburn. Healed cryolesions that are exposed to the sun may require extra sunscreen protection.
Cryosurgery is also not recommended for use in areas of hair growth. These areas include around eyebrows and eyelashes, as well as the scalp. Even very brief freezing treatments can destroy hair follicles.
Overview of the cryosurgical procdure:
Cryosurgery is a wonderfully simple procedure. For most lesions, there is no required skin preparation. However, lesions that have a thick keratotic layer may respond to cryosurgery better if the keratotic layer is removed. For thick warts, patients may need to apply salicylic acid for a couple weeks to peel off the top layer prior to cryosurgery. An alternative to this is to let the healthcare practitioner scrape off the top layer with a blade.
The freezing session lasts a matter of seconds. The liquid nitrogen is sprayed directly on the skin lesion till the desired size ice ball is achieved in the skin. Some lesions require a freeze, defrost, refreeze technique.
The skin will react to appropriate freezing by becoming red, swelling and occasionally forming a blister. No additional skin care is required afterward. The lesion will slough off with time. Multiple cryotherapy treatments may be required, especially with warts.
Fowler, G., Pfenninger, J. Procedures for Primary Care. 2nd Ed. Mosby Inc. 2003.