Patent Application
20080294160
This invention relates to an electrosurgical probe for medically treating tissue lesions by minimally invasive surgery (MIS) or similar procedures.
Our prior patent, No. 7,160,295, whose contents are incorporated herein by reference, describes an improved electrosurgical probe for endoscopic endonasal and other procedures using a standard operating room working channel fiberoptic scope or endoscope. It employs a very long, thin, flexible, insulated, monopolar wire electrode, so thin and flexible that it can be used with a miniature or micro-sized endoscope combining imaging optics and an instrument. The endoscope may be sufficiently flexible so as to follow the contours of the patient's anatomy, and the wire electrode is sufficiently flexible so as to follow the contours of the working channel of the endoscope. A particular application of importance is the treatment of benign lesions of the larynx, especially of the vocal cords, through flexible endoscopy.
There is also a need in the art for rigid devices to simplify the treatment by MIS of tissues which cannot be easily reached by many instruments, such as epidural scar tissue, adhesions and other pathology, and spinal diseases such as intradiscal shrinkage or ablation.
An object of the invention is an improved electrosurgical probe for treating tissue.
Another object of the invention is an improved electrosurgical probe for treating tissue that can use a standard operating room working channel fiberoptic scope or endoscope.
Still another object of the invention is an improved electrosurgical probe that can be used with flexible steerable or with rigid endoscopes.
Still another object of the invention is an improved radio-frequency (RF) electrosurgical forceps for treating tissue that has in the past been treatable with difficulty and with troublesome bleeding on occasions.
In accordance with a feature of the invention, an electrosurgical probe comprises an elongated tubular member having at a proximal end a handle and at a distal end a pair of electrically-conductive jaws that can be closed under control of a surgeon operating the handle to grasp tissue. The elongated tubular member can be made sufficiently flexible that it can be used with a miniature or micro-sized endoscope combining imaging optics and an instrument channel with an overall diameter below about 3 mm or with a flexible steerable endoscope. It can also be made sufficiently stiff that it can be used with a rigid endoscope. Because of its capability of use with a miniature or micro-sized endoscope in a standard operating environment, hospital or office, it allows a surgeon to conduct a surgical procedure with improved visualization of the surgical site.
In a preferred embodiment, the probe is monopolar with both jaws connected to the electrosurgical source of electrosurgical currents. The jaws when closed form a kind of clam-shaped or boat-shaped body with the facing peripheral edges having a relatively sharp edge for tissue cutting and to focus the RF currents at the edges when they grip tissue to be removed. Preferably, one of the jaws has a sharp tooth facing the other jaw. The tooth functions to grasp tissue, and/or to hold the tissue in case of movements, and/or to tightly hold the tissue to be excised to prevent its being inadvertently dropped when excised during the procedure.
By “proximal” is meant the end closest to the connector, and by “distal” is meant the end furthest from the connector.
The construction of the invention will provide important benefits for all MIS arthroscopic or endoscopic procedures and in many cases enables the efficient delivery of radiofrequency (RF) energy technology for controlled precise tissue cutting, absorption and other tissue effects and in a safe manner. It is cost effective and considerably less expensive than other surgical modalities such as lasers where the novel electrode configuration may be of importance, as well as for general electrosurgical procedures where the volumetric reduction of tissue or ablation of tissue that is hard to reach with the known electrodes is desirable. Examples of particular procedures for which the electrosurgical electrode of the invention is particularly suitable are spinal disc ablation surgery through a cannula for treatment of herniated or bulging discs or during spinal fixation surgery, endoscopic gastroenterological surgery, and endoscopic surgery.
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 designating the same or similar elements.
In the drawings:
The reader is directed to the referenced prior patent for a more detailed description of electrosurgical procedures and principles of operation which will assist in understanding the invention described in the present application.
In the present application,
As is evident from
The jaws 22 in this example are spring loaded 24 to a closed position, which position they occupy when they are extended through the instrument channel. The surgeon holds the handle with two fingers at a cross piece 26, and with his thumb on the handle end 28. When the surgeon squeezes the handle end, the jaws assume their open position (shown in
A typical application is a procedure for the removal of polyps or the excision of benign lesions of the larynx, and especially of the vocal cords. As one preferred procedure, a flexible endoscope is introduced through the nose. When it reaches the vestibule of the larynx, the electrosurgical probe of the invention with the dimensions of a microfiber is placed into the working channel, which may be for example of 4.8 mm outside diameter and 2.2 mm inside diameter. A typical length of the tubular member 20 is about 7-10 inches with a diameter of about 2 mm. Advancing, withdrawing, and rotating the endoscope 5 permits manipulation of the active electrode end 12 in three dimensions. For large lesions, the jaws 22 are applied to the pedicle while applying cut- or cut-coagulation waveform RF electrosurgical currents from the electrosurgical apparatus 18. A power of 5 (as displayed on the instrument) can be used and varied according to the tissue response. The pedicle is cut gradually as the instrument is advanced through the endoscope until a slim pedicle remains, which can be removed while held by the jaw tooth 44 or by using conventional flexible forceps. The jaws 22 provide tactile grabbing of polyps, nodules and granulomas on the tissue. The small tooth 44 on the tip of the instrument will catch or grab the tissue which is often moving due to airway breathing. Additionally the tooth holds the tissue in place and avoids movement during the extirpation or cutting-coagulation. The jaw's configuration of straight and lengthened design with sharpened edges allows a precise cut as the RF energy flows to the metal jaws. The cut-coag RF waveforms then provide a sealing of any bleeders with minimal heat spread. The jaw tooth is important to prevent the excised tissue from falling into the lower airway.
The electrosurgical instrument of the invention is important especially for nodules of the volcal cords, polyps, and granulomas. It has the important advantages of providing a clean cut and hemostasis simultaneously. Moreover, the jaws with its tooth are important because they can grip a vocal cord tumor for excision despite abnormal movement or spasm of the cords.
The application of a 4 MHz RF in surgical procedures of the larynx causes minimal dispersion of heat beyond the tip of the electrode, allowing precise cutting and coagulation thus minimizing bleeding.
The tubular member 20 and the jaws 22 are preferably made of stainless steel though other electrically conductive metals can be used such as brass. The exposed surface of the tubular member is coated with an electrically-insulated coating. Only the jaws are bare.
A further advantage is obtained when the electrode of the invention is used with electrosurgical apparatus capable of generating RF electrosurgical currents at frequencies of about 4 MHz. The monopolar electrode jaws enables the efficient delivery of RF energy and is uniquely suited for procedures requiring controlled precise tissue excision. It offers the further advantage that it delivers lower tissue temperature profiles. Moreover, it allows more easily the extension of RF electrosurgical currents to minimal and micro invasive surgical procedures. Minimal and micro surgical procedures typically result in reduced pain and scarring, shorter recovery time and increased effectiveness compared to traditional surgical procedures. An example of suitable electrosurgical apparatus is the Model SURGITRON Dual-Frequency electrosurgical unit manufactured by and available from Ellman International, Inc. of Oceanside, N.Y.
Once the surgeon has positioned the working end 12 of the electrode with respect to the tissue to be operated on, he or she then activates the electrosurgical apparatus 18 causing a discharge of unipolar currents between a ground plate (not shown) and the bare jaws 22 capable of causing excision or ablation or shrinkage of tissue or cauterization of a blood vessel in the usual way. As with the embodiments of the prior patents, the insulating coating on the tubular member 20 will prevent accidental touching of any conductive members or patient tissue by the electrode sides, so that the unipolar discharge is localized to the region surrounding the working end 12.
The electrosurgical probe of the invention, because it combines grasping, cutting, coagulation, and soft tissue ablation, in the form of a flexible tubular member has, apart from larynx procedures, many other applications in the following endoscopic minimally invasive surgical procedures: endonasal; skull base; endosinus and transphenoidal surgery; tracheobronchial procedures; subglottic or tracheal stenosis and lesions; quick radial incisions with low tracheal perforation risk; transoral, laryngeal and orapharyngeal surgery. It can be configured to easily reach the sublaottis and the trachea, and cut and ablate airway lesions. It can be used in either flexible or rigid tip delivery.
In the embodiment of
In this description, by “elongated” or “longitudinal” is meant parallel to the long axis of the electrode (horizontal in
While the invention has been described in connection with preferred embodiments, it will be understood that modifications thereof within the principles outlined above will be evident to those skilled in the art and thus the invention is not limited to the preferred embodiments but is intended to encompass such modifications.
