Key Insights On The Surgical Efficacy Of Radiowave Technology

This author presents a guide to using radiosurgery, an advanced form of electrosurgery, to minimize tissue damage and improve the efficiency of common surgical procedures.

During the past several years, there have been many significant developments involving instrumentation used in podiatric surgery. High frequency radiowave surgery is one of the newer tools in our surgical toolbox.

Radiosurgery is an advanced form of electrosurgery. Traditional electrosurgery machines operate at much lower frequencies of 500 Khz (500,000 cycles per second) to 1.0 Mhz. Older electrosurgical machines produce more lateral heat to the surrounding tissues and surgeons rarely use them to cut soft tissue. With the older technology, wound edges are often charred and unable to be sutured. Radiosurgery’s electromagnetic energy operates at between 3.0 and 4.0 Mhz (3 and 4 million cycles per second).

There is potential for misuse and patient injury by mistakenly using low frequency electrosurgical machines for delicate cutting, incisions and excisions. It is recommended that one has an adequate understanding of radiowave or radiosurgery terminology in order to differentiate between low frequency and high frequency technologies.

Radiosurgery has many practical uses in podiatric surgery. The radiofrequency generator instrument has the ability to control bleeding via coagulation, which one can limit to just the surface area where it is needed without heavy lateral or deep tissue destruction. This conserves tissue, reduces trauma and makes the use of escharotics like silver nitrate, potassium permanganate and iodine crystals seem barbaric.

What You Should Know About The Types Of Waveforms

Approximately 75 percent of all clinical radiosurgery procedures occur with the cutting waveforms:

1. Continuous wave (fully rectified/filtered)

2. Modulated wave (fully rectified)

The fully rectified and rectified/filtered waveforms are a pure, continuous flow of high frequency waves. This filtration results in a continuous non-pulsating flow of radiowaves that provides a micro-smooth cutting flow. This feature is most advantageous for many clinical conditions. This wave produces the least amount of lateral heat and tissue destruction.

The fully rectified waveform produces a minute but perceptible pulsating effect that can, under certain conditions, slightly reduce the efficiency of the cutting effect. In addition to a smooth cut, the fully rectified waveform accompanies a very slight superficial coagulation on the tissue surfaces. This coagulation is imperceptible clinically and microscopically, but it still provides effective hemostasis.

When the tissue is areolar, a perceptible film of coagulum forms along the surface of the coated margins as the tissue heals. The coagulum does not interfere with normal healing by primary intention and peels off spontaneously when the healing is complete.

The partially rectified waveform is an intermittent flow of the high frequency waves producing hemostasis and is highly effective in sealing off bleeders up to 1/16-inch in diameter, eliminating the need to tie the bleeders off. I recommend the partially rectified wave for the indirect technique by which one can coagulate blood vessels by grasping them with a hemostat and lifting them free of surrounding tissues. The clinician then brings electrode into contact with the hemostat, 1 or 2 inches from its tips. When the partially rectified waveform is on, one can seal the walls of the vessel, making ligation unnecessary in most cases.

How The Radiowave Device Facilitates Surgical Advantages

The radiowave surgical device uses a vacuum tube and circuit within the unit to produce the higher frequencies and the purer waveforms. There are two dials on the front of the unit. One controls the dosage power and the other controls the choice of waveforms. There is a surgical handpiece and selection of surgical electrodes. The operator controls a foot pedal that sends the radiofrequency energy to the electrodes. The surgeon also uses an antenna plate on the leg of the patient.

The atraumatic nature of radiowaves provides a noteworthy advantage. The lack of trauma results in tissue healing without fibrous, contractile scar tissue, which characterizes healing of wounds created by manual cutting. As a result of these advantages, radiosurgery facilitates, accelerates and improves surgical procedures tremendously. It also helps to eliminate the unfavorable postoperative sequelae such as pain, swelling and/or infection that patients so often experience after the use of “traditional” instrumentation for comparable surgery.

Since radiosurgery requires virtually no pressure to effect a cutting action, one should rest the hand on some support in order to retain better control over the instrument. The ingredients for efficient radiosurgery are a gentle touch, digital dexterity, a fluid wrist action and a feather light touch. The tissue to be cut should be moist. If it is too dry, surface charring will occur. One can most easily moisten excessively dry tissue with wet gauze. Prior to performing an operative procedure, study the area in order to select the correct electrode, waveform and power. I recommend several practice strokes without activating the instrument to determine the correct length, depth and direction of cut.

Electrodes are made of noble alloys, come in various sizes and shapes, and vary in their clinical application. Fine-wire or needle-shape electrodes will be in most common use for cutaneous surgery. The larger the electrode, the greater the power required to affect the tissue. Fine-wire electrodes require minimal power and work nicely for incisions. One can ellipse around a skin lesion and lift up the corner with a forceps. The same needle electrode can then separate the undersurface from the dermis. Fine wire loop electrodes can plane and layer tissue. This is a procedure unique to radiowave surgery.

Podiatric surgeons will find that the most frequent application of radiowave is the treatment of cutaneous lesions. One can easily excise a lesion in this manner and send it for pathologic evaluation. Podiatric surgeons often ignore pigmented lesions on the foot and using this device would allow biopsy in the office. Biopsies can be excisional or incisional. Using the radiofrequency technique provides effective hemostasis, which lessens the risk of metastasis. Other clinical applications of radiowave surgery are matrixectomies, verrucae excision, porokeratosis excision and deeper surgery such as ganglion removal, neuroma removal, etc.

The major advantage, in comparison with other methods of surgical incision or excision, is that radiowave surgery takes little time. The equipment is simple to set up, the procedure takes little time and the control of bleeding is rapid. In comparison to the CO₂ laser, the tissue effects are similar. However, the equipment used in electrosurgery is much less expensive and has fewer hazards in comparison to lasers given that clinicians can often misdirect the laser beam outside the surgical area, creating inadvertent tissue damage and/or fire hazards.

Final Thoughts

Radiowave surgery is a procedure that clinicians can readily master and is applicable for office-based care. Radiosurgical procedures are rapid, efficient and produce excellent postoperative results. Knowledge of these techniques and their clinical applications add to the podiatrist’s range of choices for treating a variety of problems.

Dr. Davidson is in private practice with Podiatry Affiliates, PC in New York State. He is a Diplomate of the American Board of Podiatric Surgery, a Diplomate of the American Board of Podiatric Medicine, and a Fellow of the American Academy of Podiatric Sports Medicine.

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