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    CURRENT THERAPY

    J Oral Maxillofac Surg65:1785-1792, 2007

    Cutaneous Cryotherapy inMaxillofacial Surgery

    Phillip J. Ameerally, BDS, MBBS (HONS), FDSRCS, FRCS (Maxillofacial),*and Graham B. Colver, DM, FRCP, FRCPE

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    good doctor should be aware of all available ap-roaches to therapy. This applies equally to surgeonsnd physicians. Cryotherapy is frequently used byermatologists to treat mucocutaneous disease butany head and neck surgeons, while seeing some of

    he same diseases, do not have confidence in the usef this technique. This review is intended to re-waken interest in cryosurgery and show that it cane the most appropriate treatment for some condi-ions. The modern consent form demands that alter-ative methods of treatment have been discussed.his is another factor that should persuade maxillofa-ial surgeons to be aware of cryosurgery as a treat-ent option.

    istory of Cryotherapy

    Cryotherapy has long been noted as a good tech-ique that, when used correctly, can reduce pain andwelling and destroy lesions with little scarring. Thencient Egyptians, over 4,000 years ago, noticed thatooling reduced both pain and inflammation.1 Hip-ocrates recommended the use of cold to reducewelling, hemorrhage, and pain, while John Hunter in777 stated that the local tissue response to freezing

    ncludes local tissue necrosis, vascular stasis and ex-ellent healing.1 In 1899, White was the first persono use extremely cold refrigerants for medical condi-ions. He used liquefied air to treat warts, naevi, andther dermatologic conditions.1 Many refrigerantsere tried (Table 1) but liquid nitrogen, the mostopular and effective cryogen used today, only be-ame readily available after 1945. Initially, liquid ni-

    eceived from Chesterfield Royal Hospital, Calow, Chesterfield,

    K.

    *Specialist Registrar, Department of Maxillofacial Surgery.

    Consultant, Department of Dermatology.

    Address correspondence and reprint requests to Dr Ameerally:

    0 Clickers Mews, Upton one, Northampton NN5 4EE, UK; e-mail:

    [email protected]

    2007 American Association of Oral and Maxillofacial Surgeons

    278-2391/07/6509-0019$32.00/0oi:10.1016/j.joms.2006.11.016

    1785rogen was applied via cotton tips, but with improve-ent in refrigeration technology by the 1960s, open

    prays and probes became available for more success-ul cryotherapy.

    iology of Cryotherapy

    When a tissue is cooled the rate of the heat ex-hange is very complex. It depends on several factorsncluding water content, blood supply, thermal con-uctivity of the tissue, rate of freeze, and the temper-ture of the refrigerant.

    In modern cryosurgery:

    The 2 principal methods of application arethrough closed probes or by spraying liquid ni-trogen directly onto the tissues. Probes supportmore controlled conditions and may freeze deeperbecause it is possible to apply pressure on thetissues. Spray methods are more versatile but the2 methods overlap if spray cones are used toconcentrate the spray.

    The contour of the cryolesion is approximatelydome shaped down to a depth of approximately6 mm, but becomes more pyramidal at greaterdepths.2 The lateral spread of ice from the edgeof the probe or cone is approximately equal tothe depth of freeze (Fig 1).3

    The isotherms lie closer together when the rateof freezing is rapid. This implies that lethal tem-peratures are found near the base and lateralmargins of the iceball after rapid freezing.3

    Temperatures down to 50C are needed to killmalignant cells,4 and these can be obtained up to5 mm below the surface when liquid nitrogen isused.

    The mechanism of cell death includes5:

    Immediately after cryotherapy ice crystals areseen directly intra- and extracellularly.

    Extracellular ice reduces extracellular water andtherefore increases solute concentration and os-

    molality. This causes fluid shift and disrupts the

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    1786 CUTANEOUS CRYOTHERAPY IN MAXILLOFACIAL SURGERYcell membrane. Further damage is produced dur-ing the thawing process.

    Intracellular ice damages mitochondria and endo-plasmic reticulum.

    Large ice crystals are more damaging than smallones.

    Slow thawing is associated with recrystalizationof ice and is more destructive than rapid thawing.

    ryotherapy Spray Technique

    Treatment schedules can only be repeated or re-roduced if there is a standard nomenclature. Thene advocated is the freeze thaw cycle (FTC). Thepray or probe is applied continuously until the re-uired ice field has been created and only then does

    Table 1. SURFACE TISSUE TEMPERATURESATTAINABLE USING VARIOUS CRYOGENS

    Cryogen Temperature (C)

    ce 0alt ice 20O2 snow 79O2 slush 20itrous oxide 75iquid nitrogen 196

    Data from Jackson et al.1

    meerally and Clover. Cutaneous Cryotherapy in Maxillofacialurgery. J Oral Maxillofac Surg 2007.

    IGURE 1. Shape of the ice field and relationship of lateral spread tohe depth of the cryolesion.meerally and Clover. Cutaneous Cryotherapy in Maxillofacialurgery. J Oral Maxillofac Surg 2007.

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    iming begin. Thus, a 5 second FTC denotes maintain-ng a given ice field for 5 seconds. It may not beecessary to freeze continuously after establishing the

    ce field as this may create more cold injury thanequired. Intermittent spraying will usually maintainhe ice field at the required diameter.

    The lesion to be treated is outlined with a markeren. The margin for a benign lesion is usually 1 to 2m and 5 mm to 1 cm for malignant lesions. The

    iquid nitrogen spray tip is held approximately 1 cmrom the skin over the center of the area to be treatedFig 2). Spraying is commenced and the ice spreadsutward, forming a circular ice field. Once the re-uired area is frozen, the spraying is continued atufficient pressure to maintain the ice field. Neopreneones can be used to concentrate the liquid nitrogenpray and limit lateral spread of the ice field (Fig 3).lternatively, an auroscope earpiece or adhesiveutty may be used to produce an accurate ice field,educing damage to adjacent normal tissue. For peri-

    FIGURE 2. The cryotherapy spray technique.

    meerally and Clover. Cutaneous Cryotherapy in Maxillofacialurgery. J Oral Maxillofac Surg 2007.

    IGURE 3. Neoprene cones used to produce an accurate ice fieldnd protect adjacent normal tissue.meerally and Clover. Cutaneous Cryotherapy in Maxillofacialurgery. J Oral Maxillofac Surg 2007.

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    AMEERALLY AND CLOVER 1787rbital lesions, a plastic eye protector or a Jaegeryelid retractor may be used.Treatment is usually from 5 to 30 seconds depend-

    IGURE 4. Seborrhoeic keratosis treated with cryosurgery. A, Seborrhesult.

    meerally and Clover. Cutaneous Cryotherapy in Maxillofacial Sng on the pathology of the lesion. Times greater than t0 seconds may be required, but this can inducecarring.6 This technique is suitable for treatment ofiameters up to 2 cm; beyond this size the tempera-

    ratosis pretreatment. B, Post-treatment view showing excellent cosmetic

    . J Oral Maxillofac Surg 2007.oeic keure at the periphery would be insufficient for reliable

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    1788 CUTANEOUS CRYOTHERAPY IN MAXILLOFACIAL SURGERYell killing. In this case, the area can be treated as aeries of overlapping circles.

    Reproducibility of this technique can bechieved using the FTC concept. However, whenreating larger benign lesions it is acceptable to use aandom spray pattern over the surface.7

    robe Technique

    Most surgeons performing cryotherapy are familiarith the use of cryoprobes. Probe diameters range

    rom 1 mm to several centimeters depending on theize of the lesions being treated. The probe may bepplied directly to the lesion or a lubricant jelly maye used as an interface.

    orceps Technique

    Forceps technique is limited to the treatment ofkin tags. The forceps are dipped in liquid nitrogenefore grasping the stalk of the tag for 10 seconds.Regardless of the technique used, if 2 or more

    FIGURE 5. Melanotic macules of the lower lip treated

    meerally and Clover. Cutaneous Cryotherapy in Maxillofacial Sycles are required, it is important that thawing is lomplete after the initial freeze. This can be judged ashe time at which the ice has disappeared and can noonger be felt on palpation. This stage may be 3 to 4imes the duration of the freeze time. Significant cel-ular injury occurs during the thaw phase and com-lete thawing decreases cell survival.8

    linical Application of Cryotherapy

    Cryotherapy does not provide a tissue sample andndeed it may temporarily improve the appearance of

    alignant lesions, thus giving the false impression ofure. However, when dealing with clinically benignesions and most solar keratoses it is not necessary toake a pretreatment biopsy. Experienced clinicians mayhoose to treat low risk Bowens and basal cell carcino-as on the trunk and limbs without biopsy, but in all

    ther cases a pretreatment biopsy is the wisest choice.

    enign Lesions

    Cryotherapy can effectively treat numerous benign

    osurgery. A, Preoperative view. B, Postoperative view.

    . J Oral Maxillofac Surg 2007.with cryesions of the skin. Discussion of the treatment of all

  • AMEERALLY AND CLOVER 1789FIGURE 6. Auricular basal cell carcinoma treated with cryotherapy.A, Preoperative view of basal cell carcinoma of the ear. B, Basal cellcarcinoma of the ear 1 week post-treatment with