Topic

• Introduction
• Indications
• Contraindications
• Procedure
• Coding Information

Figure(s)

• Selecting a Cryosurgical Tip
• Ring Wart
• The Duration of the Freeze
• Disengaging the Tip from the Target Tissue

• Cryosurgery is a frequently performed ablative procedure that is used in the treatment of benign, premalignant, and malignant skin growths.
• Cryosurgery produces controlled destruction of skin lesions by withdrawing heat from the target tissue. Historically, physicians have used liquid nitrogen applied with cotton-tipped swabs, although modern applications generally use a probe tip containing refrigerant liquid.
• Human tissue freezes at –2.2°C, with tissue destruction occurring between –10 and –20°C. Closed probe systems using nitrous oxide can produce probe tip temperatures of –65 to –89°C.
• Cryosurgery produces an ice ball in target tissue. The edge of the ice ball only achieves a temperature of 0°C, and this area usually recovers. Cryosurgery should be performed so that the ice ball extends at least 2–5 mm beyond the edge of the lesion being destroyed. Because ice ball formation is geometric in all directions, lateral extension of the ice ball from the applicator tip gives a good estimation of the depth of ice penetration into the tissue.
• Many clinicians advocate performance of multiple freezes when cryosurgery is performed. The main advantage of the freeze-thaw-freeze technique is that greater cell death is achieved in tissue that has been previously frozen (but would otherwise recover). This advantage can be significant when treating premalignant or malignant lesions or lesions that resist freezing. Exert caution during the thaw phase, because vascular lesions may bleed on thawing.
• Cryosurgery generally produces a burning sensation during treatment, although the discomfort of injected anesthetic often exceeds the discomfort of the procedure. After the procedure, cryosurgery produces anesthesia in treated tissues.
• Frozen tissue reacts with peripheral edema immediately after thawing. Subsequent bulla formation and exudation occur before the area heals in a fine atrophic scar within 4 wks. The technique produces high cure rates with good cosmetic results.
• Certain medical conditions can produce an exaggerated tissue response to freezing of skin (listed in Relative Contraindications section). Patients with conditions that produce serum cold-induced antibodies (i.e., cryoglobulins) are at greatest risk for marked skin necrosis.

• Actinic keratosis
• Leukoplakia
• Milia
• Mucocele of lip
• Pyogenic granuloma
• Seborrheic keratosis
• Sebaceous hyperplasia
• Superficial basal cell carcinoma
• Simple lentigo
• Cherry angioma
• Verrucae vulgaris
• Hypertrophic scars
• Molluscum contagiosum
• Capillary hemangioma of newborn
• Granuloma annulare
• Solar-induced pigmentation and wrinkling
• Flat warts

Relative Contraindications

• Active, severe collagen vascular disease
• Active, severe subacute bacterial endocarditis
• Active, severe ulcerative colitis
• Active syphilis infection
• Active, severe Epstein-Barr virus infection
• Active, severe cytomegalovirus infection
• High serum level of circulating cryoglobulins
• Macroglobulinemia
• Immunoproliferative neoplasms, myelomas, lymphomas
• High-dose steroid treatment
• Acute poststreptococcal glomerulonephritis
• Chronic, severe hepatitis B infection
• Cold-induced urticaria
• Raynaud's disease (especially for procedures on digits)
• Lesions on darkly pigmented individuals (due to depigmentation from procedure)

• Pare down thick, hyperkeratotic lesions that resist cryosurgical treatment. Select a cryosurgical tip for the procedure that approximates the size of the lesion being treated (Fig. 19-1).
• Pitfall: Blood at the surface of the skin acts like an insulator against cryosurgical destruction. Do not perform cryosurgery on an actively bleeding lesion.
• Pitfall: Avoid mismatched cryosurgical tips that can result in inadequate or excessive treatment.
• Inadequate treatment of warts using a tip that is too small may result in formation of a ring wart (Fig. 19-2). Formation of a ring wart does not always imply inadequate treatment, because 5% of properly treated warts result in ring wart formation.
• Apply water-soluble gel to cryotip, and place tip on target tissue at ambient (room) temperature. Activate cryogun, causing gel to turn white. The duration of the freeze depends on the time required to produce a proper-sized ice ball (Fig. 19-3). The edge of the ice ball will recover.
• Pitfall: Use the size of the ice ball to guide the duration of the procedure. Physicians often desire to use freeze times to guide therapy. Freeze times vary substantially because of factors such as pressure, (amount of refrigerant) in tank, skin or lesion temperature, and the thickness of the lesion.
• After an adequate freeze has been obtained, deactivate the cryogun and allow the probe tip to defrost before disengaging the tip from the target tissue (Fig. 19-4). Allow adequate time for the lesion to thaw before reapplying cryotherapy. As tissue thaws, the white ice ball becomes red. Adequate thaw permits fluid and electrolyte shifts in the lesional tissue that enhance subsequent applications of cryotherapy.
• Pitfall: Do not pull the cryotip off target tissue before it has defrosted or pull cotton swab with liquid nitrogen off mucosal surface before it has thawed. Withdrawal of applicator tips before defrosting often results in removal or denuding of tissue surface.
• Pitfall: Thawing of vascular lesions—e.g., cherry angiomas or pyogenic granulomas—may bleed extensively on thawing. Be prepared for this potential bleeding; gauze can be applied using direct pressure, or Monsel's solution can be applied to control bleeding.

• Destruction performed in certain locations—e.g., penis and vulva—can be billed using a specific site destruction code.
• Specific site codes generally reimburse more than the general codes. Malignant lesion destruction (17260–17286) provides additional reimbursement when cancerous lesions are ablated.

CPT code	Description	2002 average 50th percentile fee (US$)
17000	Destruction by any method, first lesion	96
17003	Second through fourteenth lesion, each	38
17004	15 lesions	429
17110	Flat warts, molluscum, milia 14 lesions	98
17111	Flat warts, molluscum, milia 15 lesions	145

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