CHAPTER 30 Radiofrequency Surgery (Modern Electrosurgery)

Radiofrequency (RF) surgery—modern electrosurgery—has become a versatile tool for the primary care physician in dermatologic, surgical, and gynecologic applications. It is both time and cost effective, and it provides efficacious treatment for a multitude of lesions. Appropriate selection of waveform and current intensity allows excision (cutting), cutting and coagulation (blend), pure coagulation (hemostasis), or fulguration. Tissue either can be removed delicately with excellent cosmetic results or can be totally ablated. The electrosurgical unit (ESU) can be used for treatment of both benign and malignant lesions.

This chapter is based on the Ellman Surgitron (Ellman International, Inc., Hewlett, NY), a portable generator that creates high-frequency current of 3.8 to 4.0 MHz, which is comparable to the radiowave frequency for broadcasting (Figs. 30-1 and 30-2). ESU wave frequency for different brand models can vary from 500,000 to 4 million cycles (4.0 MHz) per second. All units can be used with a multitude of electrode tips for a large variety of applications. With the advent of the loop electrosurgical excision procedure (LEEP) in the 1990s, many companies introduced units into the market. Unless otherwise noted, discussion here will be in reference to the Ellman Surgitron because it is widely adapted to many dermatologic procedures. The reader can generalize the discussion to most other units quite readily.

Figure 30-1 A, Ellman Surgitron radiofrequency unit with foot pedal, antenna plate, and hand wand tip holder. A variety of electrode tips are lying above the white antenna plate. B, Ellman Dual Frequency IEC II. C, The Wallach Q500 electrosurgical unit with finger control handpiece and a variety of electrodes. D, Typical electrodes (Ellman) for skin electrosurgery (left to right): vari-tip cutting wire; ball electrode and pointed electrode for cautery or fulguration; small and large loops; diamond-shaped electrode.

(A, B, and D, Courtesy of Ellman International, Inc., Hewlett, NY. C, Courtesy of Bruno Ratensberger.)

Figure 30-2 Comparison of uses and effects of various electrical frequencies.

(Courtesy of Ellman International, Inc., Hewlett, NY.)

There is a choice of three waveform outputs plus a fulguration current (four modes). By changing waveforms, practitioners obtain different effects. The settings of the Ellman unit are described as filtered fully rectified, fully rectified, and partially rectified. These correspond with a pure cutting effect (90% cutting, 10% coagulation), a blended current to allow 50% cut and 50% coagulation, and a 90% coagulation (hemostasis) effect, respectively. A separate outlet also provides a spark-gap fulgurating current (referred to as hyfrecation) for very superficial cautery (Fig. 30-3).

Figure 30-3 Common terminology for various modes, waveform characterization, and waveform configuration for the outputs of the radiofrequency unit.

Advantages of using RF technique include rapidity of treatment, a nearly bloodless field, minimal postoperative pain, and rapid healing. Local anesthetic is used except in rare instances. Because the frequency is so high, the current from this unit passes through the body without causing painful muscle contractions or nerve stimulation (Faraday effects). Radiosurgery using the cutting wave cuts without pressure, needing only a feather-like touch, and thus minimizes tissue damage. The tissue damage that does occur is very superficial and comparable with that of proper laser use. This is in contrast to true cautery, which causes damage similar to third-degree burns. In addition, radiosurgery avoids the risk of electrical burns to the patient. Instead of a ground plate, an antenna is used to focus the “radio waves.” In contrast to other electrical units, this antenna does not have to be in contact with a patient’s skin; instead, it only needs to be under the patient near the operating field. (Most ESUs with lower-frequency output, however, do require true grounding pads or plates, so the manufacturer’s recommendations must be followed.)

The high-frequency energy of this unit is concentrated at the tip of each electrode. During each procedure, the electrode itself remains cold; however, the highly concentrated electrical energy creates molecular energy inside each cell it contacts, thereby creating intracellular heat and actually vaporizing the cell, much as a laser does. The amount of heat generated depends on the amount of time the tip is in contact with the tissue, the size of the electrode, the power setting, the type of waveform selected, and the wave frequency. Higher frequency means less contact time, finer wire, less power, a more “cutting” waveform, and less tissue damage.

High-frequency electrosurgery is now replacing many laser applications because of the minimal tissue damage, low cost of equipment, minimal maintenance, ease of treatment, and excellent long-term results. It has replaced most laser applications for the gynecologic treatment of dysplasia (conization) and condylomata. It is now also being used for blepharoplasties, radioassisted uvulopalatoplasty (RAUP) for snoring, spinal procedures, skin tightening (dual-frequency unit), and many more applications.

Indications

Radiofrequency surgery can be used for a variety of skin and mucosal lesions. It is especially helpful when good cosmetic results are essential. It is also very helpful in well-perfused areas like mucosa and the anal area because the “cut and coag” setting can be used to control the bleeding. Common uses and lesions treated are listed in Box 30-1.

Box 30-1 Common Uses of and Lesions Treated with Radiofrequency Surgery

Actinic keratoses

Basal cell cancers

Blepharoplasties

Cauterization of “bleeders”

Cervical biopsies

Cervical conizations (LLETZ, LEEP)*

Chalazions

Condylomata

Curettement and cautery (e.g., warts)

Nail plate ablation ^†

Nevi (benign)

Pyogenic granulomas

Radioassisted uvulopalatoplasties (RAUP)

Rhinophyma

Sebaceous gland hyperplasia

Seborrheic keratoses

Shave removals

Skin tags

Skin tightening (Radiage)

Squamous cell carcinomas

Syringomas

Telangiectases (spider veins) face (not recommended for legs)

Verrucae

Xanthelasma

^* See Chapter 149, Loop Electrosurgical Excision Procedure for Treating Cervical Intraepithelial Neoplasia.

^† See Chapter 29, Ingrown Toenails.

Contraindications

• Cardiac pacemakers (relative contraindication): Do not work near the heart and place the antenna (or grounding) plate well away from the heart. Use the least power possible. Activate the handpiece intermittently rather than continuously. The cutting mode is the most risky, so avoid it if possible. Use another form of treatment if it is an option. The pacers are purportedly “shielded” and the current in the ESUs should not affect them, but all things are not perfect! Therefore caution is needed. Asystole and tachycardia are potential adverse outcomes.

• Uncooperative patient.

Equipment

• Alcohol wipe

• Local anesthetic (e.g., 2% lidocaine with or without epinephrine)

• 1-mL syringe with 30-gauge needle

• ESU

• Electrode tips (depending on procedure performed): reusable or disposable

• No. 15 scalpel blade

• Antenna (or grounding) plate

• Handpiece for tips (unit can be finger-activated from this handpiece if desired)

• Foot pedal to activate handpiece (or use handpiece as above); foot pedal preferred for delicate surgeries

• Smoke evacuator (human immunodeficiency virus [HIV] and human papillomavirus [HPV] have been found in smoke plume)

• Room air purifier or exhaust fan (removes residual odor)

• Moveable cart to hold the ESU, smoker evacuator, tips, and all equipment for the procedures

• Mask

• Nonsterile gloves

• Aluminum chloride for topical control of bleeders (or Monsel’s solution if face is not involved)

• Antibiotic ointment

• Band-Aid

• Patient education handout on moist healing (which is essential to obtain optimal results). (See the sample patient education handout available online at www.expertconsult.com.)

• For LEEP supplies, see Chapter 149, Loop Electrosurgical Excision Procedure for Treating Cervical Intraepithelial Neoplasia.

The most common tips used for removal of skin lesions are the large and small loops. The ball electrode is used frequently for coagulation and for ablation of lesions. Special tips are available for matrixectomy (see later discussion and Chapter 29, Ingrown Toenails) and skin tightening (see Chapter 52, Nonablative Radiowave Skin Tightening with the Ellman S5 Surgitron [The Pelleve Procedure]).

Disposable tips are convenient but can be costly. Reusable tips must be free of carbon buildup and shiny to obtain best results. After cleaning and sterilizing, and before repeat use, the tip must be examined. If it is not shiny, the carbon can be removed in several ways:

• Use a 2 × 2-inch piece of fine sandpaper and, using the index finger to support the back side of the loop, rub it over the sandpaper. Turn it over and do the reverse side. Be sure to clean the entire wire loop.

• Purchase the cleaning “blocks” available.

• Place the units in an ultrasonic cleaner.

• Use a moistened piece of 4 × 4 gauze, insert the tip into the folded material, and activate it on the cutting setting, level 5.

When complete, the wire should be shiny (like new). One of the most common reasons for poor cutting and “stalls” during RF surgery is “dirty” (carbon-covered) reusable loops, which is avoided if disposable tips are used.

Most ESUs have digital readouts for wattage (power intensity). The Ellman simply has an intensity dial labeled 1 to 10. Each unit roughly corresponds to 10 W. For skin surgery a setting of 2 to 4 (20 to 40 W) is usually needed. (As a “default,” remember “pure cutting on level 2.”)

Use of a smoke evacuator is essential. Not only have HPV and HIV been found in smoke plume (no infections have been documented), but the smell of burning flesh is very offensive and the examination room and office can smell for hours afterward.

The dual-frequency unit (Ellman Surgitron DF IEC II; see Fig. 30-1B) is being used with increasing frequency for plastic surgery and neurosurgery applications. Its coagulation potential is much better and it can coagulate in a “wet” (bloody) field using the bipolar modality. This is achieved through the dual frequencies of 4 MHz for cutting but 1.7 MHz for bipolar coagulation. This unit will not interfere with any nearby electronics or electrical circuits. Other benefits include a higher frequency (4.0 vs. 3.8 million cycles per second) than the original equipment. There is still minimal thermal damage when cutting. It meets national safety codes for operating room use, and it is more user friendly because there is a two-pedal foot switch for cutting or coagulation and a three-button finger switch (for each modality). It has a memory for the most recent settings when turned off, digital power settings, and an audible sound when activated. This unit is significantly more expensive, and whether the benefits warrant the extra cost for the average practitioner remains to be seen. The dual-frequency unit with the special electrodes must be used for skin-tightening procedures. Those considering offering aesthetic procedures in their practice may want to consider this unit.

Technique

Proper technique is accomplished when the loop electrodes pass through the tissue smoothly, like cutting through soft butter. Generally, a motion of 5 to 8 mm/sec is appropriate. If there is excess sparking and smoke, the power setting is too high. If the flow is not smooth, the operator is going too fast, the power setting is too low, the skin is too dry or hyperkeratotic, or the electrode is dirty (debris or carbon buildup). It is important to remember that the least tissue damage occurs with the pure cutting setting. Coagulation causes the most tissue destruction. If cosmetic results are desirable, judicious use of the coagulation setting and using as little power (watts) as possible is important.

The most common use for the RF unit in primary care is removal of elevated skin lesions such as nevi and seborrheic lesions. Commonly, when using a blade to shave off a benign nevus, two things result: bleeding and an irregular surface. As the surgeon tries to smooth out the “highs” in the base of the wound, blood obscures the area. Then, as the blade is used to shave off these highs, too much tissue is removed, leaving “dips.” The “lows” (too much tissue removed) and the “highs” (too little) result in adverse outcomes with undesirable scarring. Using the RF technique, both bleeding and an uneven wound base can be avoided. In addition, any focal areas of undesirable residual tissue are removed and the edges can be smoothed for a more pleasing cosmetic result. Because the tissue left behind has minimal thermal damage, healing is quick and scarring is minimized.

The most successful technique for removing lesions appears to be first to “debulk” the majority of the lesion with a no. 15 blade in a shave fashion (see Chapter 32, Skin Biopsy). Then, use the loop electrode on a pure cutting setting of 2 (20 W) to smooth out or vaporize the base of the wound. Pinch the skin around the area to control bleeding, activate the loop, and very superficially pass the tip over/through the tissue, gradually going down until the lesion is smoothed out adequately (Fig. 30-4). This “smoothing out” of the base provides an excellent outcome with rapid healing. The “cutting” setting has 10% coagulation so bleeding is nicely controlled. The tissue is literally vaporized cell layer by cell layer. Healing results are excellent. Another advantage with the method described is that the tissue sent to pathology has no burn artifact.