Method and Equipment Selection

Main methods to deliver cryogens include the cryospray and the cryoprobe techniques. A flat cryoprobe applied with pressure can result in a deeper freeze in relation to lateral spread than obtained with the spray method. A pointed cryo probe tip produces an ice ball that is deeper than its radius on the surface whereas a round probe produces a hemisphere-shaped ice ball. Open-ended cryoprobes are devices where a central opening sprays nitrogen on center of a lesion rather than near the enclosed periphery. This is best used with a pyrometer or electrical impedance needle. When selecting a cryosurgical unit find one that is well constructed and has a good safety record. The cryogen of choice is generally LN. Solid carbon dioxide can be used for treatment of benign lesions. Nitrous oxide units are available but have disadvantages and are not recommended for treatment of malignant lesions. Fluorocarbon sprays can be used for treatment of acne pustules and cysts and for peeling of the skin surface, for acne scarring as well as treating plaques of psoriasis, actinic or seborrheic keratoses.