Curettage, cauterisation or cryocautery

Warts, verrucae, and some other skin lesions (e.g. small circumscribed tumours) can be removed with a curette, even without local anaesthesia, with a good cosmetic outcome. There is less bleeding if electrocauterisation is performed first. Cryotherapy (i.e. freezing with liquid nitrogen) also yields good results and is much less expensive than, for instance, laser treatment.

In case of warts, however, conservative treatment gives the best cosmetic result. Since warts are epidermal viral tumours, their treatment should not destroy the dermis. Therefore operations leading to scar formation should be avoided (Kunnamo I (ed), 2005) . Over-the-counter preparations and 40% salicylic acid tapes are the first choice [Evidence level B] (Gibbs S, Harvey I, Sterling J, et al., 2002) .

Curretage and cauterisation

Curettage is performed by scraping the lesion with a curette and usually precedes the scraping of vesiculobullous lesions; it can also be used to treat superficial nonmelanocytic skin cancers (Chuh AAT, Wong WCW, Wong SYS, Lee A, 2005) . Haemostasis is achieved by compression, cauterisation, or laser.

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Fig. 1. Curette

Cauterisation is the destruction of tissues by heat, electricity, laser, freze, or chemicals (Chuh AAT, Wong WCW, Wong SYS, Lee A, 2005) . Electrocauterisation involves the cauterisation (electrodesiccation) commonly used to removeunwanted tissue (e.g. skin tumour, usually with a surrounding margin of clinically unaffected tissue) or to achieve haemostasis.
NOTE: With electrocauterisation, no specimen is available for histopathological examination. Therefore, the diagnosis must be well established before considering the use of this technique.

Common indications include: viral warts, cherry angiomas, and sebaceous hyperplasia (Chuh AAT, Wong WCW, Wong SYS, Lee A, 2005) . Electrocauterisation is also considered effective for low-risk tumours (i.e. with a low risk of metastasis – small, well defined, located on flat skin surfaces). Hair-bearing sites carry the risk that a tumour extending down follicular structures may not be adequately removed.
NOTE: If the tumour extends down to the subcutaneous layer, surgical excision is preferred over curettage and cauterization.

Technical aspects (Chuh AAT, Wong WCW, Wong SYS, Lee A, 2005)

1. A grounding pad should be applied to the patient’s thigh for protection.
2. After local anaesthesia, a small electrode is applied to the skin. The electrode has high frequency electricity current at its tip.
3. Each cauterising cycle does not usually last for more than a few seconds.
4. Lesions such as viral warts or seborrhoeic keratoses may be pared away by curettage first, and the base then cauterised.
5. Healing is always by secondary intention.
6. The use of a fine tip for diathermy and the lowest effective energies to treat lesions may minimise scarring.
   

Contraindications (Chuh AAT, Wong WCW, Wong SYS, Lee A, 2005) , (Martinez JC, Otley CC, 2001) , (Naylor M, Hitt E)

A. History of anaemia, diabetes mellitus, cardiac disease, cardiac pacing, hypertrophic scars and keloids.
B. Relative contraindications to curettage and cauterization:

• the use of a hearing aid,
• basal cell carcinoma (BCC) of 2 cm or more with extension into the subcutaneous fat,
• recurrent lesions,
• aggressive subtypes of BCC or squamous cell carcinoma (SCC),
• tumours in high-risk anatomic locations (e.g. face, ears, vertex of scalp),
• tumours in areas where cosmetically unacceptable scars may result.
  

Complications of electrocautery (Chuh AAT, Wong WCW, Wong SYS, Lee A, 2005)

1. Injury to the neighbouring tissues
2. Injury to blood vessels and nerves
3. Scarring
4. Interference with pacemakers and implantable cardioversion defibrillators
   

Relative contraindications to curettage and cauterization include (Martinez JC, Otley CC, 2001) , (Naylor M, Hitt E) :

• basal cell carcinoma (BCC) of 2 cm or more with extension into the subcutaneous fat,
• recurrent lesions,
• aggressive subtypes of BCC or squamous cell carcinoma (SCC),
• tumours in high-risk anatomic locations (e.g. face, ears, vertex of scalp),
• tumours in areas where cosmetically unacceptable scars may result.

Cryotherapy

The procedure involves the application of liquid nitrogen in order to destroy the tumour cells. Commonly it is used for the treatment of warts and verrucas. It does not actually kill the viruses that cause these lesions but kills the cells that they are living in. Cryotherapy is usually reserved for smaller, clearly demarcated lesions, but it may also be appropriate for patients with large superficial tumours, multiple tumours, tumours within scars in low-risk sites, and for patients with bleeding disorders or those who cannot tolerate surgery (Naylor M, Hitt E) , (Kuflik EG, 1997) .

Liquid nitrogen should be kept at the surgery in a specially designed container since it is very cold at a temperature of –196 degrees Celsius. It will therefore freeze any tissue that it comes into contact with, similar to a thermal burn. It is applied to skin conditions via a specially designed pressurised flask with a spray effect. A variety of nozzles are available depending upon the type of condition being frozen.

A.

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B.

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Fig. 2. Cryotherapy unit (A) and cryoprobes (B)

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B.

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Fig. 3. Cryotherapy for haemorrhoids: liquid nitrogen application (A) and post-treatment effect (B). NOTE: The technique of destroying haemorrhoidal tissues with a frozen tip of a cryoprobe is rarely used nowadays due to its side effects.

Indications for cryotherapy

Typical skin lesions that are suitable for treatment with cryotherapy include:

• warts
• verrucas
• solar keratosis (sun damaged skin)
• seborrhoeic keratosis (changes of the skin with age)

Contraindications to cryotherapy include (Naylor M, Hitt E) :

• tumours with poorly defined borders,
• invasive SCC,
• aggressive subtypes of BCC,
• recurrent skin cancers,
• tumours in hair-bearing skin (to avoid a cryotherapy-induced alopecia).

Technique

The spray is applied from 10 to 30 seconds. Occasionally this may be repeated depending upon the lesion, but it can be rather uncomfortable. The number of treatments will vary depending upon a number of factors such as size and type of lesion. Following cryotherapy the lesion may gradually discolour and hopefully fall off or at least shrink.

Compared to other treatments cryotherapy is usually an effective and least time consuming way of removing skin lesions.

Glossary

HES

Hemalun Eosine Safran (histology, French: Cell components revelation method)