Patent Publication Number: US-2011054468-A1

Title: Apparatus for Performing an Electrosurgical Procedure

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to an apparatus for performing an electrosurgical procedure. More particularly, the present disclosure relates to an electrosurgical apparatus that includes a cutting element including a stationary blade and a pivoting blade. 
     2. Description of Related Art 
     Electrosurgical instruments (e.g., opened and closed type electrosurgical forceps) are well known in the medical arts and typically include a housing, a handle, one or more shafts and an end effector assembly, which includes jaw members operatively coupled to a distal end of the shaft, that is configured to manipulate tissue (e.g., grasp and seal tissue). Electrosurgical forceps utilize both mechanical clamping action and electrical energy to effect hemostasis by heating the tissue and blood vessels to coagulate, cauterize, seal, cut, desiccate, and/or fulgurate tissue. 
     Many electrosurgical instruments have been designed to incorporate a cutting or blade element which effectively severs tissue. For example, commonly-owned U.S. application Ser. Nos. 10/116,944 and 10/179,863 describe one such endoscopic instrument which effectively seals and cuts tissue along the tissue seal. Typically, the cutting element is operably associated with the jaw members of the end effector assembly of the electrosurgical forceps. 
     In some instances, the jaw members may narrow or taper near a distal tip of the jaw members, especially in those instances where the jaw members are configured for small dissection surgical procedures. Due to design constraints associated with end effector assemblies and/or jaw members, the cutting element in certain instances is prevented or impeded from cutting to the distal end of the jaw members. 
     SUMMARY 
     The present disclosure provides a forceps. The forceps includes an end effector assembly having a pair of first and second jaw members. One or both of the first and second jaw members are moveable from an open position wherein the jaw members are disposed in spaced relation relative to one another, to a clamping position wherein the first and second jaw members cooperate to grasp tissue therebetween. In embodiments, each of the first and second jaw members includes a cutting channel defined therein that extends therethrough. A cutting element is movable within the cutting channel, and includes a stationary blade and a pivoting blade, the pivoting blade configured to pivot with respect to the stationary blade when the first and second jaw members are in the clamped position and the cutting element is advanced through the cutting channel. An actuator configured to impart reciprocating movement of the cutting element. 
     The present disclosure also provides a surgical instrument configured to manipulate tissue. The surgical instrument includes a housing having a shaft that extends therefrom that defines a longitudinal axis therethrough. An end effector assembly is operatively connected to a distal end of the shaft and includes a pair of first and second jaw members. The first and second jaw members are moveable from an open position wherein the jaw members are disposed in spaced relation relative to one another, to a clamping position wherein the first and second jaw members cooperate to grasp tissue therebetween. In embodiments, each of the first and second jaw members includes a cutting channel defined therein that extends therethrough. A handle assembly operatively connects to the housing and includes a movable handle movable relative to a fixed handle operably connected to impart movement of the jaw members relative to each other. A cutting element is movable within the cutting channel, and includes a stationary blade and a pivoting blade, the pivoting blade configured to pivot with respect to the stationary blade when first and second jaw members are in the clamped position and the cutting element is advanced through the cutting channel. An actuator operably connects to the housing and is configured to impart reciprocating movement of the cutting element. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       Various embodiments of the present disclosure are described hereinbelow with references to the drawings, wherein: 
         FIG. 1  is a right, front perspective view of an endoscopic bipolar forceps suitable for use with a cutting element according to an embodiment of the present disclosure; 
         FIG. 2  is a left, front perspective view of an open bipolar forceps suitable for use with a cutting element according to an embodiment of the present disclosure; 
         FIG. 3  is an enlarged view of the area of detail illustrated in  FIG. 1  with the cutting element in a retracted position and shown within a shaft associated with the bipolar forceps illustrated in  FIG. 1 ; 
         FIG. 4  is a side view of the cutting element illustrated in  FIG. 3  in an advanced position within a pair of jaw members of the end effector assembly associated with the bipolar forceps illustrated in  FIG. 1 ; and 
         FIG. 5  is a front view of a stationary blade and a pivoting blade of the cutting element illustrated in  FIG. 3  with the stationary blade and pivoting blade shown in an initial position. 
     
    
    
     DETAILED DESCRIPTION 
     Detailed embodiments of the present disclosure are disclosed herein; however, the disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms. 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. 
     In the drawings and in the descriptions that follow, the term “proximal,” as is traditional, will refer to an end of a surgical instrument which is closer to a user, while the term “distal” will refer to an end that is farther from the user. As used herein, the term forceps is meant to include surgical instruments that are intended for use in open or closed surgical procedures including those surgical instruments that are configured for use in bipolar and monopolar modes of operation. 
     With reference to  FIG. 1 , an illustrative embodiment of an electrosurgical apparatus (e.g., endoscopic bipolar forceps  10 ) configured for use with the cutting element  200  according to an embodiment of the present disclosure is shown. Bipolar forceps  10  is shown for use with various electrosurgical procedures and generally includes a housing  20 , an electrosurgical cable  310  that connects the forceps  10  to a source of electrosurgical energy (e.g., electrosurgical generator not shown), a handle assembly  30  including a fixed handle  50  and a movable handle  40 , a rotating assembly  80 , a drive assembly (not shown), an end effector assembly  100  that operatively connects to the drive assembly. The drive assembly may be in operative communication with handle assembly  30  for imparting movement of one or both of a pair of jaw members  110 ,  120  of end effector assembly  100 . End effector assembly  100  includes opposing jaw members  110  and  120  that are operatively and pivotably coupled to each other and fixedly attached to a distal end  16  of a shaft  12  ( FIG. 1 ). In certain embodiments, each of the jaw members  110  and  120  are pivotable with respect to each other (i.e., a bilateral jaw configuration). In certain embodiments, one of the jaw members, e.g., jaw member  110 , is pivotable with respect to the other jaw member, which is stationary, e.g., jaw member  120  (i.e., a unilateral jaw configuration). Jaw members  110 ,  120  mutually cooperate to grasp, seal and, in some cases, divide large tubular vessels and large vascular tissues. Each of the first and second jaw members  110  and  120 , respectively, includes a tapered distal end, the two tapered distal ends forming a tapered height when the jaw members are clamped in the closed position ( FIG. 4 ). Forceps  10  includes an actuator or a trigger assembly  70  operably coupled to the housing  20  and configured to impart reciprocating movement of the cutting element  200  through a channel  130  defined within the jaw members  10  and  120 . A proximal end  14  of the shaft  12  is configured to mechanically engage the housing  20 . 
     Jaw member  110  includes an insulative jaw housing  117  and an electrically conductive seal plate  118 . The insulative housing  117  is configured to securely engage the electrically conductive seal plate  118 . This may be accomplished by stamping, by overmolding, by overmolding a stamped electrically conductive sealing plate and/or by overmolding a metal injection molded seal plate. All of these manufacturing techniques produce an electrode having a seal plate  118  that is substantially surrounded by the insulating substrate. Within the purview of the present disclosure, jaw member  110  may include a jaw housing  117  that is integrally formed with a seal plate  118 . 
     Jaw member  120  includes a similar structure having an outer insulative housing  127  that may be overmolded to capture seal plate  128 . 
     For a more detailed description of the bipolar forceps  10  including end effector assembly  100 , handle assembly  30  including movable handle  40 , trigger assembly  70 , electrosurgical cable  310  (including line-feed configurations and/or connections) and other operative components associated with the forceps  10 , reference is made to commonly owned United States Patent Publication No. 2003/0229344 and U.S. Pat. No. 7,150,749. 
     With reference to  FIG. 2 , an illustrative embodiment of an electrosurgical apparatus (e.g., open bipolar forceps  400 ) configured for use with the cutting element  200  is shown. Forceps  400  is configured for use with open surgical procedures and includes elongated shaft portions  412   a  and  412   b  each having a proximal end  414   a,    414   b  and a distal end  416   a  and  416   b,  respectively. Forceps  400  includes an end effector assembly  500  that attaches to the distal ends  416   a  and  416   b  of shafts  412   a  and  412   b,  respectively. Shaft  412   b  may be generally hollow to house a handswitch  450  (and the electrical components associated therewith). A proximal shaft connector  477  electromechanically engages an electrosurgical cable  470  such that a user may selectively apply electrosurgical energy as needed. More particularly, a handswitch  450  is configured to permit a user to selectively apply electrosurgical energy as needed to seal tissue grasped between jaw members  510  and  520 . 
     A ratchet mechanism  430  is disposed at the proximal ends  414   a,    414   b  of shafts  412   a,    412   b,  respectively, for selectively locking the jaw members  510  and  520  relative to one another in one or more positions during pivoting. The end effector assembly  500  includes pair of opposing jaw members  510  and  520  that are pivotably connected about a pivot assembly  465  and which are movable relative to one another to grasp tissue. Forceps  400  includes an actuating mechanism  440  to advance the cutting element  200 . More particularly, the actuating mechanism  440  includes a trigger or finger tab  443  that is operatively associated with a first gear rack (not shown) such that movement of the trigger or finger tab  43  moves the first rack in a corresponding direction. The actuating mechanism  440  mechanically cooperates with a second gear rack (not shown) that is operatively associated with a drive rod (not shown) and which advances the entire cutting mechanism  200 . 
     For a more detailed description of the forceps  400  including end effector  500 , actuation member  440  and other operative components associated with the forceps  400 , reference is made to commonly owned United States Patent Publication No. 2005/0154387. 
     With reference to now to  FIGS. 3-5 , and initially with reference to  FIG. 3 , an embodiment of a cutting element  200  configured for use with either forceps  10  or  400  is shown. For the purposes of brevity, hereinafter the cutting element  200  and operative components associated therewith will be described in terms of use with forceps  10 . 
     Cutting element  200  and operative components associated therewith may be formed from any suitable material, e.g., biocompatible grade steel. Cutting element  200  may be formed by any known methods including but not limited to stamping, machining, spot welding, and the like. Cutting element  200  is operably connected to and in mechanical communication with trigger  70 . Trigger  70  and operative components associated therewith are configured to impart reciprocating movement of the cutting element  200  through a channel  130  ( FIG. 1 ). In the embodiment illustrated in  FIG. 1 , each of the first and second jaw members define the channel  130 . Cutting element  200  includes a proximal end  206  that operably couples to a connector  208  (as best seen in  FIG. 4 ) or other suitable device that is in operative communication with the trigger  70 . In an embodiment, the proximal end  206  may operably couple to a push rod (not shown) that couples to an actuator that is movable from a proximal to distal position, such as, for example, the actuator mechanism  440  illustrated in  FIG. 2 , or other suitable actuating mechanisms, such as, for example a drive wheel that translates the push rod forward when the drive wheel is rotated. Cutting element includes a distal end  210  that includes a cutting edge  212  that is defined by a stationary blade  202  and a pivoting blade  204 . In the embodiment illustrated in  FIG. 3 , cutting edge  212  includes a generally arcuate or concave configuration. It is within the purview of the present disclosure, that cutting edge  212  may include a generally convex or straight configuration. Cutting element  200  (or portion thereof) includes a first height “H 1 ” when the cutting element  200  is in a retracted position and the stationary blade  202  and pivoting blade  204  are in a “non-folded” configuration ( FIGS. 3 and 5 ). Cutting element (or portion thereof) also includes a second height “H 2 ” when the cutting element  200  is in an advanced position and the stationary blade  202  and pivoting blade  204  are in a “folded” configuration (see  FIG. 4 ). 
     With reference again to  FIG. 3 , cutting element  200  includes stationary blade  202  and pivoting blade  204 . In some embodiments, the stationary blade  202  and pivoting blade  204  are interleaved. Pivoting blade  204  pivots with respect to the stationary blade  202  when the first and second jaw members  110  and  120 , respectively, are in the clamped position and the cutting element  200  is advanced through the channel  130  towards a distal end of the first and second jaw members  110  and  120 , respectively ( FIG. 4 ). 
     Stationary blade  202  is formed at the distal end  210  of cutting element  200 . In the embodiment illustrated in FIGS,  1 - 4 , stationary blade  202  is positioned lower than, and in an offset relation relative to, the pivoting blade  204 , as best seen in  FIG. 5 . 
     As can be appreciated, this blade configuration allows the cutting element  200  to advance through the cutting channel  130  to the distal end of the jaw members  110 ,  120  by virtue of the pivoting blade  204  being cammed to follow the tapered profile of the cutting channel  130 . In other words, as the cutting element  200  advances through the cutting channel  130 , the pivoting blade  204  of the cutting element  200  is cammed to reduce the height (from “H 1 ” to “H 2 ”) thereof to match the profile of the tapered jaw members  110  and  120 , thereby allowing the cutting element  200  to advance further along the cutting path to sever tissue. 
     This configuration of a stationary blade  202  that is positioned lower than and in an offset relation relative to the pivoting blade  204  may also provide a scissor-like cutting action between the stationary blade  202  and pivoting blade  204 , wherein the scissor-like cutting action facilitates severing of tissue when the cutting element  200  is translated through the channel  130 , especially after a tissue sealing procedure. 
     A top leading edge  204   a  of the pivoting blade  204  includes a generally rounded or curved configuration (as best seen in  FIG. 3 ). This configuration of a top leading edge  204   a  that is rounded, as opposed to a leading edge that is straight or flat, facilitates movement and/or pivoting of the pivoting blade  204  as the cutting element  200  is advanced through the cutting channel  130 . More particularly, the rounded configuration of the top leading edge  204   a  minimizes or reduces the chances of the top leading edge  204   a  cutting into an interior wall of the shaft  12  and/or jaw member  120 . Alternatively, a top leading edge  204   a  may be relatively straight of flat (as best seen in  FIG. 4 ). In an embodiment, stationary blade  202  and pivoting blade  204  are offset from each other a distance that is substantially equal to the thickness “T” of the stationary blade  202 , see  FIG. 5  for example. 
     Pivoting blade  204  is pivotably coupled to cutting element  200 . Pivoting element may be pivotably coupled to cutting element  200  by any suitable pivoting means, such as, for example, a living hinge, a pivot pin, etc. In the embodiment illustrated in  FIG. 3 , pivoting blade  204  is pivotably coupled to stationary blade  202  via a pivoting pin  216  operatively disposed adjacent proximal end  206  of cutting element  200 . Pivoting pin  216  is configured to provide a point of pivot for the pivoting blade  204  when the cutting element  200  is moved from the retracted position to the advanced position, and vice-versa. 
     In an embodiment, a spring or other suitable biasing element  218  (e.g., elastic band or the like) is operatively disposed on the cutting element  200  and operatively couples the cutting element  200  to a proximal end  222  of pivoting blade  204 . Spring  218  is configured to bias the pivoting blade  204  in an upright, or non-pivoted or unfolded position when the cutting element  200  is in the retracted position or when the cutting element is being moved from the advanced position to the retracted position. In the embodiment illustrated in  FIG. 3 , spring  218  is operatively disposed at a predetermined position on a top portion  220  of the cutting element  200 . The proximal end  222  may include a generally arcuate portion  224  that extends from a bottom portion  226  of the pivoting blade  204  to a top portion  228  of the pivoting blade  204 . 
     Pivoting blade  204  includes one or more camming structures that may be in the form of one or more protuberances or nibs  230 . Protuberance  230  is configured to contact one or more camming surfaces  232  (to be described in more detail below) such that as cutting element  200  is advanced through the channel  130 , the pivoting blade  230  is caused to pivot or deflect downward toward the stationary blade  202  to reduce the overall height of the cutting element  200  and to promote a scissor-like inter-action between the stationary blade  202  and pivoting blade  204  (as noted above this scissor-like action may facilitate severing tissue). With this purpose in mind, protuberance  230  is located at a predetermined position along a top surface  234  of pivoting blade  204  at a point that is distal the pivot pin  216 . This configuration of a protuberance  230  that is located distal a pivot pin  216  facilitates pivoting the pivoting blade  204  when the protuberance  230  contacts the camming surface  232 . That is, because the protuberance  230  is located distal the pivot pin  216 , the pivoting blade  204  is prevented from pivoting upward or toward a top portion of the shaft  12  and/or jaw member, e.g., jaw member  110 , when the protuberance contacts the camming surface  232 . The dimensions, e.g. the size, of protuberance  230  may depend on a number of factors, such as, for example, the desired rate of deflection of the pivoting blade  204  with respect to the velocity of the cutting element  200  through the channel  130  during actuation the trigger assembly  70 . 
     With continued reference to  FIG. 3 , camming surface  232  is shown. As noted above, camming surface  232  is configured to contact or cam protuberance  230  of the pivoting blade  204  such that pivoting blade  204  is caused to pivot or deflect downward towards the stationary blade  202  when the cutting element  200  is advanced distally through the channel  130 . To this end, camming surface  232  may be operatively disposed along an upper portion of the distal end of the shaft  12  and/or jaw member, e.g., jaw member  110 . 
     In the embodiments illustrated in  FIGS. 1-5 , camming surface  232  is located at each of the distal end  16  of the shaft  12  and a proximal end  238  of the jaw member  120 . More particularly, camming surface  232  extends along a top inner surface  240  of the distal end  16  of shaft  12  ( FIG. 3 ) to a top inner surface  242  of the proximal end of the jaw member  110 . Camming surface  232  includes a continuous, uniform slanted or sloped (e.g., ramp-like) configuration that includes a rate of inclination that, together with the size of protuberance  230 , provides an even, uniform camming of the pivoting blade  204  when the pivoting blade  204  is moved from the retracted to advanced position and vice-versa. 
     Alternatively, camming surface  232  may include a plurality of non-continuous or intermittent, camming surfaces  232   a  (shown phantomly in  FIG. 3 ) that, together with the size of protuberance  230 , may provide a non-uniform camming of the pivoting blade  204  when the pivoting blade  204  is moved from the retracted to advanced position and vice-versa. In either embodiment, after the cutting element  200  has fully advanced through the channel  130 , cutting element  200  or portion thereof will have a height “H 2 ”, as described hereinabove. In the instance, where a non-continuous camming surface  232   a  is implemented, after the cutting element  200  has been advanced, a final camming surface (not shown) of the plurality of camming surfaces  232   a may  be configured to cause the pivoting blade  204  to deflect downward a distance that provides cutting element  200  with a height “H 2 ”. The exact dimension or configuration of either of the camming surfaces  232  and  232   a  will depend on the contemplated uses of a manufacturer. 
     Operatively disposed on along the top inner surface  240  of the distal end  16  of the shaft  12  and/or the jaw member, e.g., jaw member  110 , may be one or more grooves or slots  250  configured to receive cutting element  200  or portion thereof In the embodiment illustrated in  FIG. 3 , slot  250  is located at each of the distal end  16  of the shaft  12  and a proximal end  238  of the jaw member  120 . More particularly, slot  250  extends along the top inner surface  240  of the distal end  216  of shaft  12  ( FIG. 3 ) to the top inner surface  242  of the proximal end of the jaw member  120  within the camming surface  232 . Alternatively, slot  250  may be located adjacent camming surface  232 . 
     Prior to cutting element  200  being actuated, cutting element  200  is in an initial retracted position and has a first height “H 1 ”. After tissue has been properly grasped and electrosurgically treated, e.g., sealed, a user may actuate or squeeze trigger  70 . Actuation of trigger  70  causes cutting element  200  to move from the initial retracted position ( FIG. 3 ) to a final advanced position. During translation of cutting element  200  through channel  130 , camming surface  232  contacts protuberance  230  of pivoting blade  204  and causes pivoting blade  204  to pivot and/or deflect downward toward stationary blade  202  ( FIG. 4 ). In the embodiment where a continuous camming surface  232  is employed, cutting element  200  severs tissue in an even, uniform fashion, i.e. scissor-like manner. In the embodiment where a non-continuous camming surface  232   a  is employed, cutting element  200  severs tissue in generally saw-tooth fashion. During the translation of pivoting blade  204  through channel  130 , the height of cutting element  200  transitions from a height “H 1 ” where the cutting element  200  is in the retracted position to a height “H 2 ” where the cutting element  200  is in the advanced position. Thus, in the instance where a distal end  170  of the jaw members narrow or taper, the cutting element  200  is not impeded or prevented from advancing to the distal end  170  of the jaw members. After tissue has been severed, actuation trigger  70  may be actuated again or released. In an embodiment, releasing trigger  70  causes cutting element to translate proximally through channel  130  and back toward the retracted position. As cutting element  200  translates proximally, pivoting blade  204  is caused to return to the initial position of the pivoting blade  204  under the bias of spring  218 . 
     From the foregoing and with reference to the various figure drawings, those skilled in the art will appreciate that certain modifications can also be made to the present disclosure without departing from the scope of the same. For example, in an embodiment it may prove advantageous to have one of the stationary blade  202  and pivoting blade  204  include one or more serrations  214  (shown phantomly in  FIG. 3 ). In this instance, the serrations  214  are intended facilitate severing tissue when the cutting element  200  is advanced through the channel  130 . Additionally, it may prove advantageous for the stationary blade  202  and pivoting blade  204  to have different dimensions. For example, pivoting blade  204  may include a depth, width, and/or height that is different from that of stationary blade  202 . As can be appreciated by one skilled in the art, the exact dimension and/or configuration of the stationary blade  202  and pivoting blade  204  with respect to each other will depend on the contemplated uses of a manufacturer. 
     In some embodiments, it may prove advantageous to have one or both of the stationary and pivoting blades  202  and  204 , respectively, define a cutting edge  212  that includes a bevel, facet, etc. 
     In some embodiments, a portion of the cutting element  200  may include one or more cam slots or grooves that are configured to receive one or more camming structures operatively disposed on the pivoting blade  204 . More particularly, an inner side surface of the cutting element  200  may include a cam slot that is configured to receive a corresponding camming structure, e.g., a cam pin disposed on an inner side surface of the pivoting blade  204 . In this instance, the cam slot may include a contour commensurate with the cam pin and may be configured to provide a path of motion for the pivoting blade  204 . In this instance, the cam slot may include a generally arcuate configuration with all points equidistant from the center of the cam pin. This combination of cam slot and cam pin may further facilitate severing tissue when the cutting element  200  is advanced through the channel  130 . As can be appreciated by one skilled in the art, the cam pin  216  and/or pivoting blade  204  may be configured to compensate for the path of motion of the cam pin. The cam slot and cam pin may be formed on the respective inner surfaces of the cutting element  200  and pivoting blade  204  may be formed by any suitable means, such as, for example, by known etching techniques. 
     While the above-referenced cutting element of the present disclosure has been described herein in terms of a cutting element  200  that includes a pivoting blade  204  that is disposed offset and above the stationary blade  202 , it is within the purview of the present disclosure to have a pivoting blade  204  that is offset and below the stationary blade  202 . As can be appreciated by one skilled in the art, in this instance certain design modifications will need to be implemented in the manufacturing process of the cutting element  200  and/or bipolar forceps  10  and the pivoting blade  204  will be configured to pivot upwards. 
     While several embodiments of the disclosure have been shown in the drawings, 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.