CRYOSURGERY Pattippa Sumalai, M.D. Jutamas Tankunakorn, M.D. 23/09/2014

 Use of extreme cold to destroy cells of abnormal or diseased tissue  Recommended for patients considered to be poor surgical candidates  Objective : to cause necrosis of tissue

Fitz patric’s dermatology edition 8 th p.2968

 Tissue destruction from cryotherapy results from - Direct cell injury - Vascular stasis - The local inflammatory response

 Freezing cells convert water to ice (crystallization) - Rapid freezing causes intracellular ice crystal formation - Slow freezing cause extracellular ice formation (less cell damage)

 During thawing, recrystallization occurs when ice crystals fuse to form large crystals that disrupt cell membranes  As the ice melts further, the extracellular environment becomes hypotonic, causing water to infuse into cells and cause cell lysis  Fast freeze and slow thaw

 After freezing stasis within the vasculature occurs  Loss of circulation ->anoxia is a major mechanism of injury from cryosurgery

 As the tissue thaws over 0 o C ( 32 o F ) - Brief hyperemic response ensues, with resultant edema and inflammation

Fitz patric’s dermatology edition 8 th p.2969

 Benign lesions : -20 to – 30 o C  Malignant tissue : -50 to – 60 o C

Bolognia edition 3 rd p.2284

LesionFreeze times ( seconds ) Verruca plana5 Solar lentigo3-5 Actinic keratosis8-10 Seborrheic keratosis10-15 Sebaceous hyperplasia5-10 Verruca vulgaris15-20 Keloid30

LesionFreeze times ( seconds ) Dermatofibroma60 Acne cysts5-15 Myxoid cysts15-20 Actinic cheilitis10-20 Bowen’s disease20

 Lateral spread of freezes - Wart 2-3 mm - BCC at least 3-5 mm or more

 Freeze-thaw cycle - Single cycle – benign and premalignant conditions - Double cycle – malignant lesions

Bolognia edition 3 rd p.2284

Bolognia edition 3 rd p.2285

 Viral contamination of liquid nitrogen may occur when treating warts or other infectious lesions if a dipstick method is used

 The most frequently used technique  Solid central : used on lesions smaller than 0.5cm  Circular intermittent pattern : 1-2 cm lesions  Paintbrush pattern : greater than 2 cm

 Contact therapy  Consist of a flat, precooled metal tip placed firmly onto lesion  Round lesions, flat surfaces

 Indication - Patient taking coagulations - Previous history of poor wound healing after standard surgical procedures - Fair skin - Multiple large lesions - Wart and molluscum contagiosum in HIV infected patients - Very extensive, recalcitrant to therapy - Patients with adverse reaction to anesthesia

 Lesions overlying nerves (postauricular nerve on the neck, digital nerves on medial and lateral fingers and toes)  Sites prone to scarring with retraction (eyelids, mucosa, nasal ala, auditory canal)  Patient with darkly pigmented skin (hypopigmentation)

Bolognia edition 3 rd p.2284

 Absolute contraindications - Lesions that require histopathology for diagnosis - Recurrent non-melanoma skin cancers

 Relative contraindications - Cold urticaria - Abnormal cold intolerance - Cryoglobulinemia or cryofibrogenemia - Tumors with indistinct borders or darkly pigmented features

 Indications - Type of skin cancer : superficial BCC, nodular or ulcerated BCC, small well-diff. SCC arising in Aks  Selection of tumors - Tumors under 2 cm in diameter - Tumors with definable margins - Infected tumors

Bolognia edition 3 rd p.2284

 Tumor over 2 cm in diameter  Recurrent tumors (exception of postradiotherapy)  Tumor with a high-recurrence rate  Tumor on the feet and lower legs, where the time of healing can be protracted up to several months  Tumor with the histological diagnosis of morpheaform or sclerotic, metatypical, or mixed type

 Single cycle of freezing is sufficient for most superficial tumors  Double cycle of freezing is used for tumors that are 3 mm or more in depth  An edematous, weeping reaction develops, follow by eschar formation  About 1 month heal by second intention, leaving a hypopigmented soft scar

 5-15 minutes after freezing : erythema, edema  Several hours : vesicle, bullae  After drying of the bullae : eschar form  Simple cleansing with soap and water  Benign and premalignant lesions heal in 1-2 weeks, malignant lesion requiring 3-4 weeks  Healing may be slower on the helix of the ear, scalp, dorsum of the hand and the lower leg  Final apperance : soft hypopigmented macular with slight textural change

 Incidence : low  May arise in several ways - Unexpected event e.g. infection - Unsatisfactory cosmetic result e.g. hypertrophic scarring - More pronounced response of the tissue to freezing than that been anticipated e.g. residual hypopigmentation

 Generally resolve spontaneously - Edema - Hypertrophic scar ( resolve within monts ) - Uncommon reactions : delayed bleeding, headache, paresthesias, neuropathy, secondary infection, syncope, nitrogen gas insufflation, milia, hyperpigmentation

 Retraction of tissue (e.g. lip, eye brows, ala nasi), tissue defect, depigmentation, notching, ectropion, alopecia, and contour defects