Electrosurgical device and method

1. Field of the Invention

The present invention relates generally to the structure and use of surgical instruments. More particularly, the present invention relates to an electrosurgical device which 15 combines a hook electrode and a reciprocatable paddle electrode intended for use in least invasive surgical procedures.

Medical treatment modalities which use electrical energy to change the structure or function of tissue or body organs 20 is referred to generally as "electrosurgery." Electrosurgical procedures most often rely on the application of very high frequency currents to excise tissue and/or close small bleeding blood vessels by electrocauterization. Of particular interest to the present invention are monopolar electrosurgical 25 devices where the patient is grounded and the very high frequency electrical current is applied to desired area of tissue or body organ using a specialized electrode. Electrosurgical procedures are particularly advantageous since they reduce bleeding from small blood vessels, facilitating the 30 handling of highly vascularized tissues while minimizing exposure of the patient to shock and pain.

Least invasive surgical (LIS) techniques, such as laparoscopic, endoscopic, and arthroscopic surgery, are generally performed through small incisions using specialized instru- 35 ments to perform desired surgical procedures. Usually, the instruments are introduced through a tube, such as a cannula, while the physician observes manipulation of the instruments through specialized imaging equipment, such as laparoscopes, endoscopes, and arthroscopes. Such LIS techniques offer significant advantages over conventional "open" surgical procedures. In particular, the LIS techniques are usually less traumatic, require a shorter recovery time, and are less costly than the corresponding conventional surgical techniques.

The combination of LIS and electrosurgical methodologies promises substantial advantages to both the patient and the treating physician. As described above, LIS reduces patient trauma resulting from the surgical incisions neces- SQ sary to access the area of the body being treated, while the use of electrosurgical techniques reduces the trauma resulting from the interventional procedure itself.

The adaption of electrosurgical instruments for use in LIS, however, can be problematic. In particular, the incorporation 55 of only a single, limited function in the electrosurgical instrument necessitates frequent exchange and replacement of instruments through the cannula. Such exchange can be time consuming and inefficient. Moreover, electrosurgical instruments frequently produce charred tissue which can §q adhere to the working surface of the instrument. Usually, such adherent debris requires that the instrument be withdrawn through the cannula and cleaned prior to reintroduction and further use. The need to repeatedly perform such cleaning is also inefficient and time consuming. 65

For these reasons, it would be desirable to provide improved electrosurgical instruments for use in LIS proce

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dures where the instruments are versatile, capable of selfcleaning, and efficient in achieving their intended purpose. It would be particularly desirable to provide electrosurgical instruments capable of combining a wide variety of different electrode surfaces, such as cylinders, cones, spatulas, balls, needles, blades, hooks, loops, and the like, in a single instrument, where the different electrode surfaces are simultaneously connected to a power source in an efficient manner.

2. Description of the Background Art

French Patent Application No. 2 265 344 describes an electrosurgical hook that can be used for gynecological, ear, nose, and throat surgery. U.S. Pat. Nos. 1,798,902; 1,881, 250; and 1,978,495, describe electrosurgical instruments including blades which reciprocate within a frame, which instruments are intended primarily for removing tonsils. U.S. Pat. No. 4,919,129, describes an electrocautery instrument having a self-cleaning reciprocatable electrode/blade. Other electrosurgical instruments are described in U.S. Pat. Nos. 1,683,708; 1,731,069; and 1,741,461.

SUMMARY OF THE INVENTION

The present invention is an electrosurgical probe which combines a pair of separate electrode surfaces which can be used alternatively or in combination for performing electrosurgical procedures. The probe is constructed to permit relative reciprocation of the two electrode surfaces so that either surface can be selectively extended relative to the other to permit its use in a laparoscopic or other surgical procedure. Exemplary electrode surfaces include cylinders, cones, spatulas, balls, needles, blades, hooks, loops, and the like.

The electrosurgical probe comprises an outer elongate body having a proximal end, a distal end, and a lumen extending between said ends. An inner elongate member is reciprocatably mounted within the lumen of the body, and both the outer elongate body and the inner elongate member define exposed electrode surfaces near their distal ends. Moreover, portions of both the outer elongate body and the inner elongate member are electrically conductive and may be coupled to a power supply through an electrical conductor located on a handle which is disposed at the proximal ends of both the body and the member. A mechanism, such as a trigger or pull bar, is provided on the handle for reciprocating the body relative to the member so that either electrode surface can be selectively extended. In this way, the electrosurgical probe can be connected to a power source and either of the electrode surfaces can be selectively utilized by simply extending the surface using the reciprocating mechanism on the handle.

An exemplary embodiment of the present invention is an electrosurgical probe which can be used in either a "hook mode" or a "spatula mode," where the respective hook and spatula components are uniquely arranged to provide both enhanced tissue dissection and cauterization as well as the ability to clean the probe in situ, i.e., without removal from the area of the body being treated. These features are particularly advantageous when the probe is used in least invasive surgical (LIS) procedures, such as laparoscopic, endoscopic, and arthroscopic procedures. In a particularly preferred construction, the electrosurgical probe can also provide for irrigation and/or aspiration of the body region being treated.

The exemplary embodiment of the electrosurgical probe comprises an elongate, usually rigid, probe body having a 20

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proximal end and a distal end. The elongate body is connected to both a surgical hook and a paddle element (which acts as the "spatula") at its distal end, and the body is electrically conductive so that power may be supplied to both the surgical hook and the paddle element through an 5 electrical connector located near the proximal end of the body. A means is provided for reciprocating the surgical hook and the paddle element relative to each other so that either the hook or the paddle element can be selectively exposed at the distal tip of the elongate probe body. Preferably, the surgical hook will be fixed to the elongate body, and the paddle element will be mounted at the distal end of a shaft which is slidably received in an axial lumen of the elongate body. Other configurations, however, would be possible so long as they allow for selective exposure of both the surgical hook and paddle element as well as allowing for 15 electrical conduction to the hook and paddle.

In a preferred aspect of the present invention, the elongate body of the probe includes an electrically-conductive tubular sleeve having a lumen which slidably receives the shaft carrying the paddle element. The surgical hook is fixedly attached to the forward end of the sleeve, and both the sleeve and the shaft are electrically conductive, typically being composed at least partly of metal. The electrical connector is attached to the proximal end of the shaft, and contact between the shaft and the sleeve assures that the electric power will be fed to both the surgical hook and the paddle element. The outer surface of the sleeve will be covered with an insulating material in order to prevent unintended electrical contact.

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While the construction just described provides a monopolar instrument, where the patient's body acts as the second pole to complete the circuit, the present invention is also suitable for bipolar designs, i.e., where the device itself provides a pair of electrodes for electrotherapy. For 35 example, the surgical hook, paddle element, or both, can be formed as laminated structures including at least two metal (electrically conductive) layers separated by an insulating layer. Such metal layers can thus provide the two electrodes necessary for the bipolar design. 40

In a second preferred aspect of the present invention, the surgical hook includes at least one, and usually two, planar faces. The paddle element includes a planar surface (or two planar surfaces) that is (are) disposed to slide past and cause a shearing action with the planar face(s) of the surgical hook. 45 Such a shearing action enhances the ability of the surgical hook to dissect tissue and other body structures as well as providing an in situ cleaning capability to remove char and other debris which might otherwise collect on the surgical hook during use. In a particularly preferred configuration, 50 the paddle element has a forked construction which provides for a pair of parallel planar surfaces which engage planar faces on opposite sides of the surgical hook.

According to the method of the present invention, the electrosurgical probe is introduced into an internal body 55 location through an access tube, such as a cannula. One of the electrode surfaces, for example, the surgical hook or the paddle element, on the probe is then selectively engaged against tissue or other body structure, while current is applied to effect dissection or cauterization. The method 60 further comprises selectively retracting the extended electrode surface to expose the other electrode surface when it is desired to use said other surface in an electrosurgical procedure. In this way, the treating physician has ready access to two different electrosurgical capabilities without 65 the need to exchange instruments, for example, by removing a first instrument from a cannula and reconnecting a new

instrument to the power source and inserting the new instrument back into the cannula. The method of the present invention further comprises cleaning of the electrode surfaces by relative reciprocation of one surface past the other. This is a particular advantage with the hook and spatula embodiment where cleaning may be accomplished by reciprocating the paddle element past the planar face(s) of the hook. Preferred use of the electrosurgical method is for dissecting the cystic duct from its surrounding or enclosing tissue and the gallbladder from its attachment to the liver.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an electrosurgical probe constructed in accordance with the principles of the present invention.

FIG. 2 is a detailed view of the distal end of the electrosurgical probe of FIG. 1, with portions broken away, shown with its paddle element in a retracted configuration.

FIG. 3 is a detailed view of the distal end of the electrosurgical probe of FIG. 1, shown with the paddle element in its extended configuration.

FIG. 4 is a cross sectional view of the electrosurgical probe of FIG. 1.

FIGS. 5 and 6 are top plan views of the distal end of the electrosurgical probe, shown in cross-section, with the paddle element illustrated in the extended and retracted configurations, respectively.

FIGS. 7 and 8 are side elevational views of the distal end of the electrosurgical probe, shown in cross-section, with the paddle element illustrated in the extended and retracted configurations, respectively.

FIG. 9 illustrates an alternate configuration of the electrosurgical probe of the present invention where a first electrode surface is a cone and a second electrode surface is a needle.

FIGS. 10A-10C illustrate another alternate embodiment of the electrosurgical probe of the present invention where the electrode surfaces are a cylinder and needle, respectively.

FIGS. 11A-11C illustrate yet another alternate embodiment of the electrosurgical probe of the present invention where the electrode surfaces are a spatula and needle, respectively.

FIGS. 12A-12D illustrate yet another alternate embodiment of the electrosurgical probe of the present invention where the electrode surfaces are a ball and needle, respectively.

FIGS. 13A-13C and 14A-14C illustrate two additional alternate embodiments of the electrosurgical probe of the present invention where the electrode surfaces are a hook and a spatula, respectively.

FIGS. 15A-15C and 16A-16C illustrate two more alternate embodiments of the electrosurgical probe of the present invention where the electrode surfaces are a ball and a hook, respectively.

FIGS. 17A-17C and 18A-18C illustrate yet two more embodiments of the electrosurgical probe of the present invention where the electrode surfaces are a loop and a spatula, respectively.

FIGS. 19A-19C illustrate an additional embodiment of the electrosurgical probe of the present invention where the electrode surfaces are a ball and a spatula, respectively.

FIGS. 20A-20C illustrate a further alternate embodiment