Cryosurgery

Advantages

Cryosurgery is an inexpensive, rapid, and simple technique that does not require complicated apparatus.
Anesthesia is usually not necessary.
Postoperative pain is minimal.
Bleeding is not a problem during or after treatment.
Sutures are not necessary, and scarring is generally minimal or absent.
It is a relatively risk-free treatment for the cryosurgeon who treats some skin conditions in patients who are infected with human immunodeficiency virus. These include patients with molluscum contagiosum, condylomata acuminatum, Kaposi sarcoma, and warts.

Disadvantages

Young children do not tolerate cryosurgery well.
Scarring may occur, particularly if lesions are overzealously frozen or if the patient tends to heal with hypertrophic scars or keloids.
Postinflammatory pigmentary alterations may occur; more often, hypopigmentation results because of the destruction of melanocytes.

Technique

Cotton Tip Applicator Technique

Place LN₂ in a Styrofoam cup.
Dip a cotton swab into the cup.
Touch the lesion with the saturated cotton-tipped applicator, with a minimal amount of pressure, and create a 2- to 3-mm zone of freeze around the lesion for a total of 4 to 5 seconds (Fig. 35.19).
The skin turns white. Care must be taken to avoid dripping onto surrounding, normal skin.

Cryospray Technique

The standard instrument used is a handheld Cryogun, which operates under a working pressure of approximately 6 psi (Figs. 35.20 to 35.23).
Nozzle attachments with apertures of varying diameter for spray application are available (the “A” nozzle applies the greatest amount of spray; the “D” has the least amount for delicate work).
Generally, no local anesthesia is necessary.
For smaller lesions, this procedure involves treating the center of the lesion and allowing the freeze to spread laterally.
The time of application varies, depending on the thickness of the lesion.
Standardization of freeze times is difficult to categorize for the treatment of benign and premalignant lesions. The goal is to produce, with either the swab or spray technique, a solid ice ball that extends 2 mm onto the surrounding normal skin.

Postoperative Course and Wound Care

Mild to moderate swelling may occur at the lesion site.
A blister or blood blister may form within 24 hours and resolves in 2 to 7 days.
The lesion site may be cleansed with soap and water during the exudative stage.
The lesion site starts to dry at the end of the exudative stage and then sloughs.
A crust, which loosens spontaneously, commonly occurs.

Helpful Hints

It is best to underfreeze lesions; they can be retreated at a later date.
For anxious children, a topical anesthetic such as EMLA cream (eutectic mixture of local anesthetics) can be applied under occlusion 1 hour before cryosurgery to decrease the discomfort associated with the procedure.
Alternative delivery methods that can help minimize pain are shown in Figs. 35.23 and 35.24.

Outline
Advantages
Disadvantages
Technique
Postoperative Course and Wound Care