Abstract:
An electrosurgical instrument and system and method for performing electrosurgery therewith is disclosed. The electrosurgical system includes an electrosurgical generator adapted to supply electrosurgical energy to tissue. The electrosurgical system includes an electrosurgical instrument that provides a shaft, such as a laparoscopic shaft, having at the distal end thereof an end effector. The end effector may include without limitation a pair of movable jaws adapted to perform tissue fusion and/or vessel sealing. The electrosurgical instrument includes a movable thumb lever in operable communication with the shaft to enable the surgeon to rotate the shaft in an ergonomic, single-handed manner.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to an electrosurgical forceps and more particularly, the present disclosure relates to an endoscopic bipolar electrosurgical forceps having a shaft rotatable by the selective actuation of a thumb lever. 
         [0003]    2. Background of Related Art 
         [0004]    Electrosurgical forceps utilize both mechanical clamping action and electrical energy to affect hemostasis by heating the tissue and blood vessels to coagulate, cauterize and/or seal tissue. Many surgical procedures require cutting and/or ligating large blood vessels and large tissue structures. Due to the inherent spatial considerations of the surgical cavity, surgeons often have difficulty suturing vessels or performing other traditional methods of controlling bleeding, e.g., clamping and/or tying-off transfected blood vessels or tissue. By utilizing an elongated electrosurgical forceps, a surgeon can either cauterize, coagulate/desiccate and/or simply reduce or slow bleeding simply by controlling the intensity, frequency and duration of the electrosurgical energy applied through the jaw members to the tissue. Most small blood vessels, i.e., in the range below two millimeters in diameter, can often be closed using standard electrosurgical instruments and techniques. However, larger vessels can be more difficult to close using these standard techniques. 
         [0005]    In order to resolve many of the known issues described above and other issues relevant to cauterization and coagulation, a recently developed technology has been developed by Valleylab, Inc. of Boulder, Colo., a division of Covidien, called vessel or tissue sealing. The process of coagulating vessels is fundamentally different than electrosurgical vessel sealing. For the purposes herein, “coagulation” is defined as a process of desiccating tissue wherein the tissue cells are ruptured and dried. “Vessel sealing” or “tissue sealing” is defined as the process of liquefying the collagen in the tissue so that it reforms into a fused mass with limited demarcation between opposing tissue structures. Coagulation of small vessels is sufficient to permanently close them, while larger vessels and tissue need to be sealed to assure permanent closure. 
         [0006]    In order to effectively seal larger vessels (or tissue) two predominant mechanical parameters are accurately controlled—the pressure applied to the vessel (tissue) and the gap distance between the electrodes—both of which are affected by the thickness of the sealed vessel. More particularly, accurate application of pressure is important to oppose the walls of the vessel; to reduce the tissue impedance to a low enough value that allows enough electrosurgical energy through the tissue; to overcome the forces of expansion during tissue heating; and to contribute to the end tissue thickness which is an indication of a good seal. Various force-actuating assemblies have been developed in the past for providing the appropriate closure forces to affect vessel sealing. For example, one such actuating assembly has been developed by Valleylab, Inc. of Boulder, Colo., a division of Covidien, for use with Valleylab&#39;s vessel sealing and dividing instrument for sealing large vessels and tissue structures commonly sold under the trademarks LIGASURE™, LIGASURE 5mm™, LIGASURE ATLAS®. The LIGASURE ATLAS® is presently designed to fit through a 10 mm cannula and includes a bi-lateral jaw closure mechanism and is activated by a foot switch. Co-pending U.S. application Ser. Nos. 10/179,863, 10/116,944, 10/460,926, 10/953,757, and 11/595,194, and PCT Application Serial Nos. PCT/US01/01890 and PCT/7201/11340 describe in detail the operating features of the LIGASURE devices and various methods relating thereto. The contents of each of these applications are hereby incorporated by reference herein. 
         [0007]    During electrosurgical procedures, such as vessel sealing, the particular characteristics of a patient&#39;s anatomy may require the surgeon to employ specific surgical techniques. For example, the angle at which a vessel is to be sealed may be dictated by adjacent anatomical structures, as well as the target vessel itself. Anatomical structures may dictate that a surgeon manipulate an electrosurgical instrument in a precise manner in order, for example, to traverse a path to the surgical site. Such manipulations may include varying the attitude of the instrument jaws in order to achieve the desired operative result. 
       SUMMARY 
       [0008]    The present disclosure is directed to an electrosurgical instrument having a housing that includes a movable thumb handle disposed thereon that is rotatable about a first axis defined by a driveshaft having a first end and a second end. The driveshaft is operably coupled at a first end thereof to the thumb handle and a second handle thereof to a drive assembly. The electrosurgical instrument in accordance with the present disclosure includes a shaft coupled to the housing and rotatable about a second axis defined longitudinally therethrough and having an end effector disposed at a distal end thereof for performing an electrosurgical procedure. In use, a surgeon may rotate the shaft and end effector by manipulating the thumb handle, for example, in a leftward or rightward direction. Advantageously, an instrument in accordance with the present disclosure allows a surgeon to manipulate the instrument, including effectuating the rotation of the shaft, using a single hand. 
         [0009]    The disclosed electrosurgical instrument includes a drive assembly configured to couple the driveshaft and the rotatable shaft, wherein a rotation of the thumb handle and driveshaft is translated into a rotation of the rotatable shaft. In embodiments, the drive assembly includes a driving element operably coupled to a second end of the driveshaft and a driven element operably coupled to a proximal end of the shaft. The driving element and driven element cooperate to translate rotation therebetween. In embodiments, the driving element and/or driven element may be a bevel gear or friction roller configured to cooperate to translate rotational motion therebetween. 
         [0010]    Also disclosed is an electrosurgical system that includes an electrosurgical generator configured to generate electrosurgical energy. The electrosurgical generator may be operatively coupled to the presently disclosed electrosurgical instrument for performing electrosurgical procedures, for example without limitation, cutting, blending, coagulating, ablation, and vessel sealing. In embodiments the electrosurgical generator may supply electrosurgical signals in the radiofrequency range, for example without limitation the 200 kHz-3.3 mHz range, and/or the electrosurgical generator may supply electrosurgical signals in the microwave range, for example without limitation the 900 mHz-2.0 gHz range. 
         [0011]    A method of performing electrosurgery is disclosed herein which includes the steps of providing an electrosurgical module configured to generate electrosurgical energy; providing the electrosurgical instrument described hereinabove; providing a cable assembly configured to operably couple the electrosurgical module and the electrosurgical instrument; actuating the movable thumb handle to rotate the end effector; and applying electrosurgical energy to tissue. In embodiments, the end effector assembly provides two jaw members movable from a first position in spaced relation relative to one another to at least a second position closer to one another for grasping tissue therebetween. In embodiments, the disclosed method includes the step of positioning the jaw members around tissue therebetween and moving the jaw members from a first position in spaced relation relative to one another to at least a second position closer to one another to grasp tissue therebetween. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The above and other aspects, features, and advantages of the present disclosure will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings wherein: 
           [0013]      FIG. 1  is an oblique view of an electrosurgical system in accordance with the present disclosure; 
           [0014]      FIG. 2  is a cutaway view of an exemplary electrosurgical instrument having a thumb lever in accordance with the present disclosure; 
           [0015]      FIG. 3A  is a perspective view of an exemplary electrosurgical instrument in accordance with the present disclosure having a thumb lever in a center position; 
           [0016]      FIG. 3B  is a perspective view of an exemplary electrosurgical instrument in accordance with the present disclosure having a thumb lever in a left position; 
           [0017]      FIG. 3C  is a perspective view of an exemplary electrosurgical instrument in accordance with the present disclosure having a thumb lever in a right position; 
           [0018]      FIG. 4A  is a perspective view of an electrosurgical instrument in accordance with the present disclosure shown with an end effector in a first position to grasp and seal a tubular vessel or bundle through a cannula; 
           [0019]      FIG. 4B  is a perspective view of an electrosurgical instrument in accordance with the present disclosure shown with an end effector in a second position to grasp and seal a tubular vessel or bundle through a cannula; 
           [0020]      FIG. 5A  is a view of thumb lever having a thumb saddle in accordance with the present disclosure; and 
           [0021]      FIG. 5B  is a view of thumb lever having a thumb paddle in accordance with the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    Particular embodiments of the present disclosure will be described hereinbelow with reference to the accompanying drawings; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure. 
         [0023]    In the drawings and in the descriptions which follow, the term “proximal,” as is traditional, shall refer to the end of the instrument which is closer to the user, while the term “distal” shall refer to the end which is farther from the user. Relative terms, such as “left”, “right”, “clockwise”, and “counterclockwise” shall be construed from the perspective of the user, i.e., from a proximal viewpoint facing distally. 
         [0024]    The present disclosure includes an electrosurgical apparatus that is adapted to connect to an electrosurgical generator that includes a control module configured for electrosurgical procedures. 
         [0025]    With reference to  FIG. 1 , an illustrative embodiment of an electrosurgical system  1  is shown. Electrosurgical system  1  includes a generator  200  that is configured to operatively and selectively couple to electrosurgical instrument  10  for performing an electrosurgical procedure. It is to be understood that an electrosurgical procedure may include without limitation seating, cutting, coagulating, desiccating, and fulgurating tissue, all of which may employ RF energy. Electrosurgical instrument  10  may be a bipolar forceps. Generator  200  may be configured for monopolar and/or bipolar modes of operation. 
         [0026]    With particular respect to the prior disclosure, generator  200  includes a control module  300  that is configured and/or programmed to control the operation of generation of  200 , including without limitation the intensity, duration, and waveshape of the generated electrosurgical energy, and/or accepting input, such as without limitation user input and sensor input. Generator  200  generates electrosurgical energy, which may be RF (radio frequency), microwave, ultrasound, infrared, ultraviolet, laser, thermal energy or other electrosurgical energy. An electrosurgical module  220  generates RF energy and includes a power supply  250  for generating energy and an output stage  252  which modulates the energy that is provided to the delivery device(s), such as an end effector  100 , for delivery of the modulated energy to a patient. Power supply  250  may be a high voltage DC or AC power supply for producing electrosurgical current, where control signals generated by the system  300  adjust parameters of the voltage and current output, such as magnitude and frequency. The output stage  252  may modulate the output energy (e.g., via a waveform generator) based on signals generated by control module  300  to adjust waveform parameters, e.g., waveform shape, pulse width, duty cycle, crest factor, and/or repetition rate. Control module  300  may be coupled to the generator module  220  by connections that may include wired and/or wireless connections for providing the control signals to the generator module  220 . 
         [0027]    As shown in  FIG. 1 , electrosurgical instrument  10  also includes an electrosurgical cable  22  which connects the electrosurgical instrument  10  to the generator  200 . Cable  22  is internally divided into cable leads (not explicitly shown) which are designed to transmit electrical potentials through their respective feed paths through the electrosurgical instrument  10  to the end effector  100 . It is contemplated that generators such as those sold by Valleylab, a division of Covidien, located in Boulder, Colo. may be used as a source of electrosurgical energy, e.g., Ligasure™ Generator, FORCE EZ™ Electrosurgical Generator, FORCE FX™ Electrosurgical Generator, FORCE 1C™, FORCE 2™ Generator, SurgiStat™ II or other envisioned generators which may perform different or enhanced functions. One such system is described in commonly-owned U.S. Pat. No. 6,033,399 entitled “ELECTROSURGICAL GENERATOR WITH ADAPTIVE POWER CONTROL”. Other systems have been described in commonly-owned U.S. Pat. No. 6,187,003 entitled “BIPOLAR ELECTROSURGICAL INSTRUMENT FOR SEALING VESSELS”. 
         [0028]    In one embodiment, the generator  200  includes various safety and performance features including isolated output and independent activation of accessories. It is envisioned that the electrosurgical generator includes Valleylab&#39;s Instant Response™ technology features which provides an advanced feedback system to sense changes in tissue 200 times per second and adjust voltage and current to maintain appropriate power. 
         [0029]    Electrosurgical instrument  10  can be any type of electrosurgical apparatus known in the available art, including but not limited to electrosurgical apparatuses that can grasp and/or perform any of the above mentioned electrosurgical procedures. One type of electrosurgical apparatus  10  may include bipolar forceps as disclosed in commonly-owned United States Patent Publication No. 2007/0173814 entitled “Vessel Sealer and Divider For Large Tissue Structures”, which is hereby incorporated by reference in its entirety for all purposes herein. 
         [0030]    With reference now to  FIGS. 1 and 2 , electrosurgical instrument  10  is shown for use with various electrosurgical procedures and includes a housing  52  having a fixed handle assembly  50 , a movable handle assembly  30 , a trigger assembly  70 , a rotating collar  80 , a thumb lever assembly  90 , a shaft  12 , a jaw drive assembly (not explicitly shown), a shaft drive assembly  102 , and an end effector  100 , which mutually cooperate to grasp, seal and divide large tubular vessels and large vascular tissues. Although the majority of the figure drawings depict an electrosurgical instrument  10  for use in connection with endoscopic surgical procedures, the present disclosure may be used for more traditional open surgical procedures. Shaft  12  includes a distal end  16  dimensioned to mechanically engage the end effector  100 , a central portion  14  which mechanically engages the housing  20 , and a proximal end  18  dimensioned to engage lever drive assembly  102  as further described hereinbelow. Shaft  12  is rotatable approximately 180 degrees about the longitudinal axis A-A thereof and is operatively associated with housing  52 . 
         [0031]    Fixed handle assembly  50  may be integrally associated with housing  52 . Movable handle  30  is movable relative to fixed handle  50 . Fixed handle  50  may be oriented about 30 degrees relative to the longitudinal axis of shaft  12 . Fixed handle  50  and/or movable handle  30  may include one or more ergonomic enhancing elements to facilitate handling, e.g., scallops, protuberances, elastomeric material, etc. In embodiments, movable handle  30  has an opening  40  defined therein which may facilitate grasping by permitting the fingers of a user to pass therethrough, as can be appreciated. 
         [0032]    Thumb lever  90  is operatively associated with housing  52  and is rotatable through an arc of about 180 degrees about the rotational axis “B-B” (See  FIG. 1 ). Thumb lever assembly  90 , shaft  12 , and lever drive assembly  102  cooperate to translate the side-to-side motion of thumb lever  90  about the B-B axis thereof into rotational motion of shaft  12  about the A-A axis. Thumb lever  90  includes a hub  93  disposed at the distal end of thumb lever  90  having a driveshaft  94  extending therefrom into housing  52  along axis “B-B”. Driveshaft  94  may be coupled to hub  93  by any suitable means, for example without limitation, by threaded fastener (not explicitly shown), adhesive, or clip. In embodiments, driveshaft  94  may be integrally formed with hub  93  and/or thumb lever  90 . Thumb lever  90  may include a recess  101  configured to improve the rigidity and reduce the material volume thereof. Thumb lever  90  at a proximal end thereof includes a thumb ring  91  defining an opening  92  adapted to accommodate a finger, i.e., thumb, of a user. In other envisioned embodiments best illustrated by  FIGS. 5A and 5B , thumb lever  90  at the proximal end may include a thumb saddle  911  or a thumb paddle  921 . Thumb saddle  911  or thumb paddle  921  may additionally include texturing, protrusions, or ribbing  912 ,  922 . In embodiments, housing  52  includes a contoured region  55  configured to provide clearance for thumb lever  90  and/or thumb ring  91 . 
         [0033]    Driveshaft  94  is supported within housing  52  by driveshaft sleeve  96  which may be integrally formed with housing  52 . Driveshaft sleeve  96  has an inside diameter dimensioned to allow free rotation of driveshaft  94  within driveshaft sleeve  96  while maintaining alignment of driveshaft  94  with lever drive assembly  102 . In embodiments, driveshaft sleeve  96  may include a bearing (not explicitly shown) such as without limitation ball bearing, roller bearing or friction bearing. In embodiments, the clearance between driveshaft  94  and driveshaft sleeve  96  may be dimensioned to achieve a predetermined amount of friction. 
         [0034]    Lever drive assembly  102  includes bevel gear  98  that is disposed upon the lower end  103  of driveshaft  94  and bevel gear  99  that is disposed upon the proximal end  18  of shaft  12 . Bevel gear  99  engages bevel gear  98  to communicate the side-to-side motion of thumb lever  90  about the B-B (i.e., vertical) axis thereof into rotational motion of shaft  12  about the A-A (i.e., longitudinal) axis. In embodiments, bevel gears  98  and  99  have a unity (1:1) gear ratio. In other envisioned embodiments, bevel gears  98  and  99  have a non-unity gear ratio whereby shaft  12  is driven at a rotational rate greater, or alternatively, less than, that of driveshaft  94 . Bevel gears  98  and  99  may be arranged such that a clockwise rotation of driveshaft  94  imparts a clockwise rotation to shaft  12 , or alternatively, a clockwise rotation of driveshaft  94  imparts a counterclockwise rotation to shaft  12 . In yet other embodiments, the relationship between the rotation of driveshaft  94  and the rotation of shaft  12  is switchably selectable. 
         [0035]    The present disclosure is not limited to the use of bevel gears to translate motion between the driveshaft and shaft. Other envisioned embodiments are disclosed wherein friction rollers, pulley and belts configurations, sprocket and chain configurations, and the like perform the function of lever drive assembly  102  and/or bevel gears  98  and  99 . 
         [0036]    Shaft  12  includes a shaft proximal portion  19  thereof that extends into housing  52 . Shaft proximal portion  19  is supported within housing  52  by shaft sleeve  97  and  97 ′ which may be integrally formed with housing  52 . Shaft sleeve  97 ,  97 ′ have an inside diameter dimensioned to allow free rotation of shaft  12  and thus shaft proximal portion  19  within sleeves  97 ,  97 ′ while maintaining alignment of shaft  12  and thus shaft proximal portion  19  with lever drive assembly  102 , i.e., maintaining the engagement of bevel gears  98  and  99 . In embodiments, shaft sleeves  97 ,  97 ′ may include a bearing (not explicitly shown) such as without limitation ball bearing, roller bearing or friction bearing. In embodiments, the clearance between shaft proximal portion  19  and driveshaft sleeves  97 ,  97 ′ may be dimensioned to achieve a predetermined amount of friction. 
         [0037]    In use, electrosurgical instrument  10  may be introduced to the surgical site of patient P through a cannula or trocar port  410  as best illustrated in  FIG. 4A  whereby end effector  100  may be positioned to grasp and/or seal vessel V. As can be seen, thumb lever  90  has been moved into a left position which, in the illustrated embodiment, has caused end effector  100  to advantageously rotate to a clockwise position that is well-suited for grasping vessel V, while permitting housing  52  to remain in substantially fixed position that may remain well-placed, for example, in the hand of the surgeon. Turning now to  FIG. 4B , electrosurgical instrument  10  is positioned to grasp vessel V′ of patient P′, where vessel V′ follows a substantially different path from that of vessel V of  FIG. 4A . Thumb lever  90  has accordingly been moved into a right position to cause end effector  100  to rotate to a counterclockwise position well-suited for grasping vessel V′, while permitting housing  52  to remain in substantially fixed position as described hereinabove. 
         [0038]    While several embodiments of the disclosure have been shown in the drawings and/or discussed herein, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.