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

2.  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

3. Fitz patric’s dermatology edition 8 th p.2968

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

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

6.  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

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

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

9. Fitz patric’s dermatology edition 8 th p.2969

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

11. Bolognia edition 3 rd p.2284

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

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

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

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

16. Bolognia edition 3 rd p.2284

17. Bolognia edition 3 rd p.2285

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

19.  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

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

21.  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

22.  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)

23. Bolognia edition 3 rd p.2284

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

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

26.  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

27. Bolognia edition 3 rd p.2284

28.  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

29.  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

30.  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

31.  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

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

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