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Electrosurgery in general practice

Richard Hooker
MB BS DCH
GP Principal
The Holland Park Surgery
London

The most memorable New Year's resolution I can recall is "to make a new friend". I have reinterpreted this in my medical practice as "acquire a new skill or interest". In 2003, having attended an inspirational presentation on skin surgery given by a local GP, I resolved (for 2004) to refine my skills in this area.
The minor surgery incentives following the introduction of the 1990 GP contract favoured the development of cryosurgery (cheap, quick, simple, low risk and tidy) and the contraction of cutting services. As a result, with the exception of cryosurgery, our training practice in West London had become surgically inert and the clinicians deskilled. However, following intensive high-quality training we now host a skin surgery service for practices within Kensington and Chelsea Primary Care Trust. The service is going from strength to strength and has been one the most stimulating and rewarding enterprises that I have been involved in. In addition to the satisfaction one derives from taking on a fresh challenge, there are clear benefits for patients, local clinicians and the practice.
If it is your practice's intention to offer anything more than the most rudimentary service, then some form of electrosurgical equipment is essential. I feel that the single most useful piece of equipment that you can invest in is a hyfrecator (see Figure 1). There is some overlap in the use of a hyfrecator, an electrocautery unit, cryotherapy and laser. The prohibitive cost of laser equipment essentially limits its use to specialist centres. We purchased both a hyfrecator and an electrocautery unit when we developed the practice-based service. The former is used several times each week without fail, whereas the latter has not been used at all after one year of service provision.

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Electrocautery
Electrocautery was first developed in the 1920s. It causes tissue destruction using a hot wire tip. It can be used to cauterise wounds following curettage or shave excision. If a fine tip is employed it can be used to treat spider naevi and telangiectasia. It has the advantages of being relatively cheap and simple to use. The tips, although delicate, are self-sterilising. There is a risk of burning healthy tissue if the tip is allowed to glow red hot (in use it should be hot enough to char gauze but not glowing red/white hot). The operator should handle gauze swabs with care as these can ignite, and alcohol-based skin preparations must be avoided. Local anaesthesia should be used during electrocautery procedures.

The hyfrecator
The hyfrecator has been in use for over 50 years. It is portable, versatile and very easy to use. The apparatus converts domestic alternating current into high-frequency alternating current (low power, 0.1-30 watts). As this current passes through human tissue of high resistance, heat is generated, leading to tissue damage. There are many hyfrecator units on the market. I will discuss the Conmed Hyfrecator 2000 (previously known as the Birtcher) as this unit is simple, in wide use and the one that we have at the surgery. It comes with a comprehensive instruction manual and two useful, albeit rather American, videos. If it is feasible I would recommend shadowing a colleague using a hyfrecator to familiarise yourself with its workings.
Essentially the unit consists of a box, a "pen" attached to the box by an electrical lead, and a metal hyfrecator tip (see Figure 2). The box converts the current, which can be set at high (for cautery or coagulation) or low (to desiccate small vessels such as spider naevi). The pen has buttons to allow the operator to adjust the current and to turn the current on and off. The electrical cable connecting the pen to the unit is delicate and should be handled with care. I use a disposable pen sheath to minimise the risk of contamination of the pen during any cutting procedure. A wide range of electrode/hyfrecator tips is available. I only use two "electrolase" tips: a blunt disposable hyfrecator tip for most procedures and a sharp tip for desiccation of small vascular naevi. Tips can be purchased in boxes of 50.

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Hyfrecator uses
I hold a minor surgery list once a week and will inevitably use the hyfrecator several times, usually for "cold" electrocautery. If the tip of the unit is in contact with tissue as the electric current is applied, tissue damage is caused by electrodesiccation. Fulguration/fulgurisation (destroying tissue using an electric current) occurs when there is a gap between the tip of the electrode and the tissue and a spark jumps between the two. Unsurprisingly this is more likely to char the skin and may cause more scarring. The charred skin forms a protective barrier and, as a result, there is less deep tissue damage with fulguration.
The wound caused by shave excision or curettage can be cauterised in a matter of seconds using a disposable blunt tip, and any ragged tissue remnants can be destroyed. In order to minimise tissue damage, the unit should be set to the lowest output that cauterises the wound effectively. Fine adjustments to the output can be made while operating using the buttons on the pen. A foot control attachment is available but is only really necessary if the operator is going to use bipolar electrodes for coagulation (the disposable monopolar tips will suffice).
Wound cautery is most effective if the wound is relatively dry. The wound can be kept dry by placing a gauze swab between the wound and the hyfrecator tip while using the tip to dab the wound with the gauze frequently between applications of current. A similar approach can be used for coagulation if simple measures have failed to affect haemostasis (eg, during ellipse excision of a mole). Relatively large areas can be cauterised quickly by "scribbling" over the wound with the tip in contact or just above the wound (the latter technique will result in fulguration). Cauterised wounds >1cm diameter are more likely to become infected with organisms such as Staphylococcus aureus. As a rule I will not perform a procedure that will leave a wound of this size. I apply a small film of antibiotic cream (eg, fucidin) over cauterised wounds in order to reduce postoperative infection. Some authorities recommend washing cauterised wounds twice daily and then applying a fine layer of white soft paraffin.
Box 1 lists the dermatological uses of the hyfrecator.

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Treating common skin lesions with the hyfrecator
Occasionally I use the unit to deal with other lesions such as warts and warty lesions, xanthelasmata or vascular lesions such as spider naevi. Using a blunt tip, warts and xanthelasmata can be desiccated, making them relatively simple to curette followed by cautery of the wound. I treat warts only if the patient is very keen to have treatment and cryotherapy has failed.
Skin tags, molluscum, milia and other small cysts can be electrodesiccated in the same way (and left to separate - the underlying tissue should take between one and three weeks to heal).
Spider naevi may respond very well to desiccation. Use either a blunt or fine tip and place this on the feeder arteriole. Apply a very low current for one second (it should blanch the lesion). Review the patient in three weeks and repeat if necessary. Excessive treatment may leave a depressed scar.
A similar approach can be used for facial telangiectasias, the operator working along the line of the lesion in steps. The patient should be aware of the risk of a fine white line remaining at the site of treatment.
 
Local anaesthetic
Local anaesthetic should be used for most procedures. Electrodesiccation of telangiectasias and small lesions

Electrosurgical equipment and pacemakers
Electrocautery apparatus does not affect pacemaker operation. There is a theoretical risk that the hyfrecator might result in pacemaker failure, and its use with the disposable monopolar tips is best avoided. Bipolar diathermy can be used, and the operator should refer to the manufacturer's guidelines and the patient's cardiologist.

Electric burns
There is a theoretical risk of the patient experiencing a high-frequency electric burn when using the hyfrecator with the disposable tips. The operator should be familiar with measures to minimise the risk of this happening.

Conclusion
Electrosurgery is a relatively cheap, simple and flexible technology that has a number of applications in primary care. The hyfrecator is arguably the most versatile apparatus and is very straightforward to use. Once employed, it will seem indispensable to any clinician wishing to offer comprehensive dermatological surgery services.

Further reading
Cautery and electrodesication.
In: Lawrence C, editor. An introduction to dermatological surgery. 2nd ed. London: Churchill Livingstone; 2002