This invention relates to an electrosurgical instrument useful for tissue modulation, skin resurfacing, coagulation, hemostasis and other electrosurgical procedures. It also relates to an attachment for a standard electrosurgical handpiece that will cause the electrosurgical electrode to vibrate when activated.
Ultrasonic-ultrasound technology used in conjunction with a standard surgical scalpel is a known surgical procedure. It typically has the following disadvantages:
The surgical blades must be sharp, similar to scalpel blades.
The cutting speed and coagulation effect are inversely related. With ultrasound/ultrasonic technology, it is important to control or balance a number of factors for good surgical results, including (a) power (b) blade sharpness (c) tissue tension (d) grip force/pressure.
(a) Power-increasing power increases cutting speed but decreases coagulation; less power decreases cutting speed and increases coagulation. The ultrasonic vibration is typically 55,500 Hz and remains the same at all power levels.
(b) Blade Sharpness-Blades must be sharp to get cutting results.
(c) Tissue Tension-More coagulation is achieved with slower cutting when tissue tension is reduced. Faster cutting results in less coagulation by increasing tissue tension.
(d) Grip Force/Pressurexe2x80x94Gentle force or light pressure achieves more coagulation with slower cutting. A firmer grip force achieves less coagulation and faster cutting. The balance is often difficult for the surgeon to control. Dissection cutting uses force directed energy. Cavitational bubbles can result from pressure differentials at the ultrasonic blade tip.
The typical components of an ultrasonic scalpel are:
Generatorxe2x80x94Microprocessor-controlled high frequency switching power supply that drives the acoustic system in the handpiece.
Handpiecexe2x80x94Contains a transducer that consists of a piezoelectric ceramic that expands and contracts to convert the electrical energy from the generator into mechanical vibration. The ultrasonic vibration is transmitted from the transducer through an extending rod to the attached scalpel blade. The blade extender is supported by silicone rings positioned at nodes to direct the flow of energy in a longitudinal direction and to prevent energy from being dissipated on the sheath.
While it is believed that others may have attempted to convert the ultrasonic scalpel to electrosurgery, to our knowledge, such attempts have not proven satisfactory, mainly because the use of the standard ceramic transducer imposed unreasonable demands of size and power in order to produce sufficient ultrasonic wave generation within the handpiece.
An object of the invention is an improved electrosurgical instrument for applying electrosurgical currents to the tissue of a patient in a more effective and controlled manner.
Another object of the invention is a procedure for more evenly distributing electrosurgical currents to the tissue of a patient being treated.
The essence of the invention is to vibrate the active electrosurgical electrode that modulates the patient""s tissue. We have found that vibrating the electrode causes a more even distribution of the RF electrosurgical currents to the tissue site being treated. In addition, another advantage of the vibration is that it enhances the effectiveness of the radiofrequency energy because it allows minimal tissue contact and a superficial light touch. The normal reaction is for the surgeon to use pressure during surgical procedures that actually reduces the effect of the radiofrequency energy on the tissue. With RF electrosurgical currents, the lighter the touch or contact, the greater the effect of the radiofrequency energy on the water molecules of the tissue in contact. The enhancement of the vibration reduces the normal reaction of pressure and enhances the radio frequency performance by allowing a light touch to the tissue thereby creating maximum performance out of the radiofrequency device. Less tissue contact equals better performance.
In accordance with a preferred embodiment of the invention, simultaneous transmission of radiofrequency energy and vibratory ultrasonic energy via a simple efficient handpiece attachment enables a surgeon to modulate all types of tissues with different degrees of effectiveness. The combination of the invention enhances the proven effectiveness of both radiofrequency and ultrasonic technology.
The invention is of especial value when applied to skin resurfacing, but will also be of value for tissue modulation, coagulation, hemostasis and other electrosurgical procedures. In an electrosurgical skin planing procedure, it enables physicians to offer to patients a dermatologic treatment that is efficiently performed, easily learned and thus performed at a significantly reduced cost, with less tissue damage compared to procedures done heretofore, and, most important, with better control over the depth of skin treatment. Other disciplines that can use this technology include neurosurgery, laparoscopy, gynecology, urology, and head and neck surgery.
Vibration of the electrode can be achieved by vibrating the entire handpiece that holds the electrode or by transferring the effect of the vibration to the active part of the electrode. It will prove of benefit with various known electrode shapes and sizes, including the electrode described in U.S. Pat. No. 5,746,746.
In accordance with another preferred embodiment of the invention, we have found an improved surgical effect by adding to a standard radiofrequency (RF) electrosurgical handpiece a vibrator device capable of vibrating at a speed of the order of 8,000-12,000 revolutions per minute (8K-12K rpm).
In accordance with another preferred embodiment of the invention, experiments have demonstrated that when a vibrational effect at approximately 10K rpm is combined radiofrequency energy such as produced with the ellman Surgitron Dual Frequency electrosurgical unit by attaching a vibrator device onto the RF handpiece, improved performance is achieved when the vibrational radiofrequency is realized and simultaneously applied by applying RF energy and switching on the vibrator to vibrate the electrosurgical electrode mounted in the standard handpiece or any electrosurgical device. Among other things, it is highly effective in rapidly moving through all tissue thickness for a complete cutting effect with little to no adjacent tissue charring. The effect of the vibration offers the advantage of even distribution of the RF energy to the skin surface. This even distributon of radiofreqency has the advantage that it cannot be ordinarily obtained by the use merely of manual light touch of the surgeon. Since the RF energy effect is increased by the lighter touch or minimal contact with the skin surface or tissue, the combination of the ultrasonic effect added to the RF electrode produces maximum effect of the RF energy.
Further, each waveform mode of the RF energy is greatly enhanced by the simultaneous application of the vibratory activity. Cutting alone with the RF current and vibration becomes much faster, and movement through the tissue meets much less resistance. In the cut and coagulation mode, a fast movement through tissue is realized while simultaneously creating a more aggressive coagulation of blood vessels. The hemostatic effect while quickly and smoothly cutting is quite controlled while reducing the margin of burned tissue edges. In the coagulation mode, the simultaneously combing of vibration with RF energy quickly allows a rapid hemostasis and control of bleeding vessels.
Among the procedures for which the invention is especially suitable, but to which it is not limited, are dermal browlift, removing vascular lesions, hair removal, skin resurfacing, and tissue vaporization of skin lesions.
The electrosurgical procedure has the important advantage of being able to remove tissue with minimum surgeon pressure while at the same time coagulating the cut tissue causing minimum bleeding. It is preferred that the electrosurgical currents used be above 2 MHz, and preferably about 4 MHz. At these high frequencies, commonly referred to as radiosurgery, cutting is accomplished by volatilizing intracellular fluids at the point of the transmitting electrode contact which is primarily responsible for only small lateral heat spread and thus less damage to neighboring cell layers.
Although it is preferred that the radiosurgery device be above 2 MHz, and preferably about 4 MHz, it will be realized that the effect of the vibration will enhance even lower frequency electrosurgery instruments.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described the preferred embodiments of the invention, like reference numerals or letters signifying the same or similar components.