Patent Publication Number: US-9901390-B2

Title: Vessel sealing instrument with cutting mechanism

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation application of U.S. patent application Ser. No. 14/086,399 filed on Nov. 21, 2013, which is a continuation application of U.S. patent application Ser. No. 13/227,220 filed on Sep. 7, 2011, now U.S. Pat. No. 8,591,510, which is a divisional application of U.S. patent application Ser. No. 12/233,157 filed on Sep. 18, 2008, now abandoned, the entire contents of each of which are hereby incorporated by reference. 
    
    
     BACKGROUND 
     The present disclosure relates to a forceps used for both endoscopic and open surgical procedures that includes a variety of electrode assemblies configured to allows a user to selectively treat and/or cut tissue. More particularly, the present disclosure relates to a forceps that includes a pair of opposing jaw members configured to grasp tissue and allow a user to selectively treat tissue utilizing electrosurgical energy and/or allow a user cut tissue utilizing one or more mechanical or electro-mechanical cutting mechanisms. 
     TECHNICAL FIELD 
     Open or endoscopic electrosurgical forceps utilize both mechanical clamping action and electrical energy to effect hemostasis. The electrode of each opposing jaw member is charged to a different electric potential such that when the jaw members grasp tissue, electrical energy can be selectively transferred through the tissue. A surgeon can either cauterize, coagulate/desiccate and/or simply reduce or slow bleeding, by controlling the intensity, frequency and duration of the electrosurgical energy applied between the electrodes and through the tissue. In order to effectively seal vessels or tissue, two predominant mechanical parameters must be accurately controlled: the pressure applied to the tissue; and the gap distance between the electrodes. 
     Vessel or tissue sealing is more than “cauterization” which involves the use of heat to destroy tissue (also called “diathermy” or “electrodiathermy”). Vessel sealing is also more than “coagulation” which is the process of desiccating tissue wherein the tissue cells are ruptured and dried. “Vessel sealing” is defined as the process of liquefying the collagen, elastin and ground substances in the tissue so that the tissue reforms into a fused mass with significantly-reduced demarcation between the opposing tissue structures. 
     Typically and particularly with respect to endoscopic electrosurgical procedures, once a vessel is sealed, the surgeon has to remove the sealing instrument from the operative site, substitute a new instrument through the cannula and accurately sever the vessel along the newly formed tissue seal. As can be appreciated, this additional step may be both time consuming (particularly when sealing a significant number of vessels) and may contribute to imprecise separation of the tissue along the sealing line due to the misalignment or misplacement of the severing instrument along the center of the tissue seal. 
     SUMMARY 
     The present disclosure relates to an end effector assembly for use with an instrument for sealing and cutting tissue and includes a pair of opposing first and second jaw members movable relative to the other from a first position wherein the jaw members are disposed in spaced relation relative to one another to a second position wherein the jaw members cooperate to grasp tissue therebetween. Each jaw member includes a jaw housing and an electrically conductive surface adapted to connect to a source of electrosurgical energy such that the electrically conductive surfaces are capable of conducting electrosurgical energy through tissue held therebetween to effect a tissue seal. One (or both) of the electrically conductive surfaces includes a channel defined therein that extends along a length thereof that communicates with a nozzle disposed in the jaw housing. The nozzle is configured to direct high pressure fluid from a fluid source into the channel for cutting tissue grasped between the jaw members. 
     In one embodiment, the nozzle communicates with one or more fluid conduits disposed within the jaw housing that are configured to convey high pressure fluid from a fluid source. One or more valves may be included that are configured to regulate the flow of high pressure fluid from the fluid source. 
     In another embodiment, each electrically conductive surface includes a channel defined therein that extends along a length thereof that communicates with a corresponding nozzle disposed within each respective jaw housing. The nozzle(s) may be tapered either longitudinally or transversally depending upon a particular purpose. 
     The present disclosure also relates to an end effector assembly for use with an instrument for sealing and cutting tissue and includes a pair of opposing first and second jaw members movable relative to the other from a first position wherein the jaw members are disposed in spaced relation relative to one another to a second position wherein the jaw members cooperate to grasp tissue therebetween. Each jaw member includes a jaw housing and an electrically conductive surface adapted to connect to a source of electrosurgical energy such that the electrically conductive surfaces are capable of conducting electrosurgical energy through tissue held therebetween to effect a tissue seal. An adhesive strip is disposed along a length of one (or both) of the electrically conductive surfaces. After electrical activation of the electrically conductive surfaces to effect a tissue seal, the adhesive strip is configured to retain a portion of the tissue seal to essentially tear the portion of the tissue seal away from remaining tissue when the tissue is removed from between the jaw members. The adhesive strip may be configured to include a heat-activated adhesive. 
     In one embodiment, the adhesive strip includes a plurality of nozzles disposed in the jaw housing operatively coupled to an adhesive fluid supply. The plurality of nozzles may be configured to communicate with one or more fluid conduits disposed within the jaw housing that convey the adhesive fluid from an adhesive fluid supply. One or more valves may be included that are configured to regulate the flow of adhesive fluid from the adhesive fluid supply. One or more of the plurality of nozzles may be tapered to direct the flow of the adhesive fluid onto the adhesive strip in a uniform and consistent manner to facilitate separation of tissue. The adhesive fluid supply may include a heat-activated adhesive fluid. 
     The present disclosure also relates to an end effector assembly for use with an instrument for sealing and cutting tissue and includes a pair of opposing first and second jaw members movable relative to the other from a first position wherein the jaw members are disposed in spaced relation relative to one another to a second position wherein the jaw members cooperate to grasp tissue therebetween. Each jaw member includes a jaw housing and an electrically conductive surface adapted to connect to a source of electrosurgical energy such that the electrically conductive surfaces are capable of conducting electrosurgical energy through tissue held therebetween to effect a tissue seal. A cutting mechanism with a sharpened leading edge is fixed between the jaw members near a proximal end thereof. The sharpened leading edge of the cutting mechanism is positioned to cut tissue between the jaw members upon forward movement of the jaw members along the tissue seal. A stop member may be disposed at the distal end of one of the jaw members that is dimensioned to maintain a gap distance between the jaw members during electrical activation of the electrically conductive surfaces. 
     In one embodiment, the stop member is operatively affixed to a guide rail-system disposed within one of the jaw housings that allows the jaw members and the cutting mechanism to move forward over the stop member to sever tissue along the tissue seal. 
     The present disclosure also relates to an end effector assembly for use with an instrument for sealing and cutting tissue and includes a pair of opposing first and second jaw members movable relative to the other from a first position wherein the jaw members are disposed in spaced relation relative to one another to a second position wherein the jaw members cooperate to grasp tissue therebetween. Each jaw member includes a jaw housing and an electrically conductive surface adapted to connect to a source of electrosurgical energy such that the electrically conductive surfaces are capable of conducting electrosurgical energy through tissue held therebetween to effect a tissue seal. One or both of the jaw members includes an elongated perforation strip that extends inwardly from the electrically conductive surface thereof. The elongated perforation strip is dimensioned to perforate the tissue upon closure of the jaw members against tissue and activation of the electrically conductive surfaces to effect a tissue seal. The perforation strips on each respective jaw member may be configured to intermesh with one another upon closure of the jaw members against tissue and activation of the electrically conductive surfaces to effect a tissue seal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments of the subject instrument are described herein with reference to the drawings wherein: 
         FIG. 1A  is a right, perspective view of an prior art endoscopic bipolar forceps having a housing, a shaft and an end effector assembly having a pair of opposing jaw members affixed to a distal end thereof; 
         FIG. 1B  is an enlarged, left perspective view of the end effector assembly with the jaw members shown in an open configuration; 
         FIG. 1C  is an enlarged, right side view of the end effector assembly of  FIG. 1B ; 
         FIG. 2  is an enlarged, left perspective view of an alternate embodiment of an end effector assembly according to the present disclosure having a high pressure fluid nozzle disposed therein for cutting tissue; 
         FIG. 3A  is an enlarged, left perspective view of an alternate embodiment of an end effector assembly according to the present disclosure having a centrally disposed adhesive strip for cutting tissue; 
         FIG. 3B  is an enlarged, left, perspective view of an alternate embodiment of an end effector assembly according to the present disclosure having a centrally disposed adhesive strip for cutting tissue that is operably coupled to an adhesive fluid supply; 
         FIG. 4A  is an enlarged, side view of an alternate embodiment of an end effector assembly according to the present disclosure having a centrally disposed fixed cutter; 
         FIG. 4B  is an enlarged, side view of an alternate embodiment of an end effector assembly according to the present disclosure having a centrally disposed fixed cutter that is configured to ride atop an isolated stop member, the jaw members and the cutter being shown in a first retracted position before tissue cutting; 
         FIG. 4C  is an enlarged, side view of an alternate embodiment of an end effector assembly according to the present disclosure having a centrally disposed fixed cutter that is configured to ride atop an isolated stop member, the jaw members and the cutter being shown in a second extended position after tissue cutting; and 
         FIG. 5  is an enlarged, right perspective view of an alternate embodiment of an end effector assembly according to the present disclosure having a pair of opposing centrally disposed perforating strips dimensioned to perforate tissue upon closure of the jaw members against tissue. 
     
    
    
     DETAILED DESCRIPTION 
     Referring initially to  FIGS. 1A-1C , a bipolar forceps for use in connection with endoscopic surgical procedures is depicted. For the purposes herein, either an endoscopic instrument or an open instrument may be utilized with the various electrode assemblies described herein. Obviously, different electrical and mechanical connections and considerations apply to each particular type of instrument, however, the novel aspects with respect to the electrode assembly and the operating characteristics associated therewith remain generally consistent with respect to both the open or endoscopic designs. 
     Generally, the end effector designs depicted herein are used to cut tissue along a vessel seal. However, any one of the various designs may be utilized to cut tissue after electrically treating tissue in a different fashion (e.g., coagulating or cauterizing tissue) or for simply cutting tissue without necessarily electrically treating tissue. 
     Bipolar forceps  10  generally includes a housing  20 , a handle assembly  30 , a rotating assembly  80 , a switch assembly  70  and an electrode assembly  105  having opposing jaw members  110  and  120  that mutually cooperate to grasp, seal and divide tubular vessels and vascular tissue. More particularly, forceps  10  includes a shaft  12  that has a distal end  16  dimensioned to mechanically engage the electrode assembly  100  and a proximal end  14  that mechanically engages the housing  20 . The shaft  12  may include one or more known mechanically engaging components that are designed to securely receive and engage the electrode assembly  100  such that the jaw members  110  and  120  are pivotable relative to one another to engage and grasp tissue therebetween. 
     The proximal end  14  of shaft  12  mechanically engages the rotating assembly  80  to facilitate rotation of the electrode assembly  100 . In the drawings and in the descriptions which follow, the term “proximal”, as is traditional, will refer to the end of the forceps  10  which is closer to the user, while the term “distal” will refer to the end which is further from the user. Details relating to the mechanically cooperating components of the shaft  12  and the rotating assembly  80  are described in commonly-owned U.S. patent application Ser. No. 11/827,297 entitled “VESSEL SEALER AND DIVIDER”. 
     Handle assembly  30  includes a fixed handle  50  and a movable handle  40 . Fixed handle  50  is integrally associated with housing  20  and handle  40  is movable relative to fixed handle  50  to actuate the opposing jaw members  110  and  120  of the electrode assembly  100  as explained in more detail below. 
     As mentioned above, electrode assembly  100  is attached to the distal end  16  of shaft  12  and includes the opposing jaw members  110  and  120 . Movable handle  40  of handle assembly  30  imparts movement of the jaw members  110  and  120  about a pivot  160  from an open position wherein the jaw members  110  and  120  are disposed in spaced relation relative to one another, to a clamping or closed position wherein the jaw members  110  and  120  cooperate to grasp tissue therebetween. 
     Referring now to  FIGS. 1B and 1C , enlarged views of an end effector assembly  100  of a prior device are shown in an open position for approximating tissue. Jaw members  110  and  120  are generally symmetrical and include similar component features which cooperate to permit facile rotation about pivot pin  160  to effect the sealing and dividing of tissue. As a result and unless otherwise noted, only jaw member  110  and the operative features associated therewith are describe in detail herein but as can be appreciated, many of these features apply to jaw member  120  as well. 
     Jaw member  110  also includes a jaw housing  116 , an insulative substrate or insulator  114  and an electrically conducive surface  112 . Insulator  114  is configured to securely engage the electrically conductive sealing surface  112 . 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 an electrically conductive surface  112  that is substantially surrounded by an insulating substrate  114 . 
     As mentioned above, jaw member  120  includes similar elements which include: a jaw housing  126 ; insulator  124 ; and an electrically conducive sealing surface  122  that is dimensioned to securely engage the insulator  124 . Electrically conductive surface  122  and the insulator  124 , when assembled, form a longitudinally-oriented channel  168  defined therethrough for reciprocation of the knife blade  205 . Knife channel  168  facilitates longitudinal reciprocation of the knife blade  205  along a preferred cutting plane to effectively and accurately separate the tissue along the formed tissue seal. Although not shown, jaw member  110  may also include a knife channel that cooperates with knife channel  168  to facilitate translation of the knife through tissue. 
     Jaw members  110  and  120  are electrically isolated from one another such that electrosurgical energy can be effectively transferred through the tissue to form a tissue seal. Electrically conductive sealing surfaces  112  and  122  are also insolated from the remaining operative components of the end effector assembly  100  and shaft  12 . A plurality of stop members  150  may be employed to regulate the gap distance between the sealing surfaces  112  and  122  to insure accurate, consistent and reliable tissue seals. 
       FIGS. 2-7  show various embodiments of different jaw member configurations for selectively cutting tissue disposed between opposing jaw members. Although is some instances only one jaw member, e.g., jaw member  220 ,  320  and  420  is shown for the various envisioned embodiments, it should be understood that a complementary jaw member having similar operating components may be utilized for sealing purposes or to facilitate the cutting process. 
       FIG. 2  shows one embodiment of a jaw member  220  for use with the forceps  10  described above. Jaw member  220  includes an insulative housing  224  having an electrically conductive surface  222  disposed thereon configured for conducting energy to tissue. A longitudinally-oriented channel  225  is defined within the electrically conductive surface  222  and extends from a proximal end of the conductive surface  222  to a distal end thereof. Channel  225  is configured to fluidly communicate with a nozzle  227  disposed in housing  224 , which is, in turn, operatively coupled to a high pressure fluid supply  250  via conduit  235  disposed through jaw member  220 . Nozzle  227  is configured to redirect the flow of fluid  228  from the high pressure fluid supply  250  and conduit  235  into the channel  225 . Nozzle  227  may be geometrically configured, e.g., longitudinally and/or transversally tapered, to increase the fluid pressure and/or mold or shape the fluid  228  exiting the nozzle  227  and channel  225  into a knife-like stream for cutting tissue disposed between the jaw members. 
     Jaw member  220  cooperates with an opposing jaw member (not shown) to approximate and seal tissue disposed therebetween. The opposing jaw member may be configured in a similar manner to direct a knife-like stream of fluid  228  into tissue to cut the tissue from an opposing direction to facilitate the cutting process. Configuring both jaw members in this manner may facilitate the cutting process and enhance the overall cutting effect. The opposing fluid channel (not shown) may be connected to the same or an independent fluid source (via a second conduit (not shown)) depending upon a particular purpose. 
     In use, the user initially energizes the opposing electrically conductive surface  222  and, for example, sealing plate  112  of  FIG. 1 , to effectively seal tissue disposed between the jaw members as described above. Once the tissue is sealed or otherwise treated, a visual or audible warning is typically displayed or otherwise transmitted to the user to indicate completion of the treatment process. If desired, the user then initiates the cutting process to separate the tissue along the tissue seal (or treatment area) by opening one or more valves  255  to induce the high pressure fluid  228  through the conduit  235  to the nozzle  227 . The high pressure fluid  228  is directed into tissue  225  to effectively sever the tissue along the longitudinally-oriented channel in the sealing surface  222 . 
     As mentioned above, the opposing jaw member (not shown) may include a similar configuration to enhance the cutting effect by directing high pressure fluid  228  into tissue from the opposite direction. Alternatively, the tissue may be cut without initially sealing or otherwise treating tissue. 
       FIG. 3A  shows another embodiment of a jaw member  320  for use with the forceps  10  described above. Jaw member  320  includes an insulative housing  324  having an electrically conductive surface  322  disposed thereon configured for conducting energy to tissue. Similar to the embodiment of the jaw member described in  FIG. 2  above, jaw member  320  cooperates with an opposing jaw member (not shown) to approximate and seal tissue disposed therebetween. The opposing jaw member may be configured in a similar manner to tear tissue from an opposing direction to facilitate the cutting process. 
     Jaw member  320  is configured to include a longitudinally-oriented strip of adhesive  325  disposed along sealing surface  322 . Adhesive strip  325  is configured to both facilitate retention of tissue during the initial treatment of tissue (e.g., tissue sealing) and effectively grip the tissue along the center of the tissue seal to induce the tissue to tear therealong when the jaw members  320  (opposing jaw member not shown) are removed. The adhesive strip  325  may be a heat-activated adhesive or a heat-enhanced adhesive to facilitate the tearing, i.e., cutting, process. 
       FIG. 3B  shows a similar embodiment of a jaw member  420  for use with the forceps  10  which also utilizes an adhesive  428  to effective tear tissue along a tissue seal. Jaw member  420  includes an insulative housing  424  having an electrically conductive surface  422  disposed thereon configured for conducting energy to tissue. Similar to the embodiments above, jaw member  420  cooperates with an opposing jaw member (not shown) to approximate and seal tissue disposed therebetween. The opposing jaw member may be configured in a similar manner to tear tissue from an opposing direction to facilitate the cutting process. 
     A longitudinally-oriented strip  425  is defined within the electrically conductive surface  422  and extends from a proximal end of the conductive surface  422  to a distal end thereof. Strip  425  is configured to include a plurality of nozzles  426  disposed in housing  424 , which are, in turn, operatively coupled to a fluid adhesive supply  450  via conduit  435  disposed through jaw member  420 . Nozzles  426  are configured to direct the flow of adhesive fluid  428  from the supply  450  and conduit  435  onto strip  425  through corresponding nozzle ports  427  arranged longitudinally along strip  425 . Nozzle ports  427  may be geometrically configured, e.g., longitudinally and/or transversally tapered, to direct the flow of the adhesive  428  fluid onto the strip in a uniform and consistent manner to facilitate separation of tissue. 
     Adhesive  428  is configured to both facilitate retention of tissue during the initial treatment of tissue (e.g., tissue sealing) and effectively grip the tissue along the center of the tissue seal to induce the tissue to tear therealong when the jaw members  420  (opposing jaw member not shown) are removed. The adhesive  428  may be a heat-activated adhesive or a heat-enhanced adhesive to facilitate the tearing, i.e., cutting, process. Moreover, the adhesive may be simultaneously or sequentially administered during or after the creation of a tissue seal. For example, the surgeon may initially energize the jaw members to seal tissue disposed therebetween and then open a valve to administer the adhesive  428  along the strip  425 . The adhesive  428  then cures and grips the tissue to promote separation thereof when the jaw members are removed. The conduit  435  may also be fluidly connected to a cleaning fluid supply (not shown) which dissolves the adhesive  428  on the strip  425  between uses such that the remaining tissue may be washed away after separation from the tissue seal. 
       FIG. 4A  shows yet another embodiment of a cutting mechanism for forceps  10  and includes end effector assembly  500  having opposing jaw members  510  and  520  that are moveable relative to one another to engage tissue therebetween to effect a tissue seal. Jaw members  510  and  520  include respective jaw housings  516  and  524  that support electrically conductive surface  512  and  522 , respectively. Each electrically conductive surface  512  and  522  is adapted to connect to an electrical energy source such that the electrically conductive surfaces  512  and  522  may conduct energy to tissue disposed therebetween to effectively treat, e.g., seal, tissue upon activation of the electrosurgical generator (not shown). 
     A cutting mechanism  540  is fixed between the jaw members  510  and  520  near a proximal end thereof. The cutting mechanism  540  includes a sharpened edge  545  at a distal end thereof. Once the tissue is treated, e.g., sealed, the surgeon relaxes the closing pressure of the jaw members  510  and  520  against the tissue (e.g., by relaxing the jaw handle  40  (See  FIG. 1 )) and simply moves the jaw members  510  and  520  forward such that the sharpened edge  545  of the knife  540  severs tissue along the tissue seal. A stop member  550  may be disposed at the distal end of one of the jaw members, e.g., jaw member  520 , to maintain a gap distance between the jaw members  510  and  520  during electrical activation to effectively seal tissue. 
     Alternatively and as shown in  FIGS. 4B and 4C , the stop member  550  may operatively couple to a guide rail-system  575  that allows the jaw members  510  and  520  and the knife  540  to move forward over the fixed stop member  550  to sever tissue along the tissue seal. The knife  540  remains fixed relative to the jaw members  510  and  520  during distal movement of the jaw members  510  and  520  over the stop member  550  (see  FIG. 4C ). 
       FIG. 5  shows yet another embodiment of a cutting mechanism for forceps  10  and includes end effector assembly  600  having opposing jaw members  610  and  620  that are moveable relative to one another to engage tissue therebetween to effect a tissue seal. Jaw members  610  and  620  include respective jaw housings  616  and  624  that support electrically conductive surfaces  612  and  622 , respectively, that are each adapted to connect to an electrical energy source to conduct energy to tissue disposed between the jaw members to effectively seal tissue. 
     Each jaw member  610  and  620  includes an elongated perforation strip  645   a  and  645   b , respectively, that extends inwardly from each respective electrically conductive surface  612  and  622 . The perforation strip  645   a  and  645   b  are aligned in general vertical registration relative to one another and each strip  645   a  and  645   b  includes a series of teeth  646   a  and  646   b , respectively, that are configured to intermesh with one another upon closure of the jaw members  610  and  620 . Alternatively, only one jaw member, e.g., jaw member  620 , may be configured to include the perforating strip  645   b.    
     In use, tissue is grasped between jaw members  610  and  620  and closed under a predetermined working pressure to effectively treat tissue, e.g., under a working pressure of about 3 kg/cm 2  to about 16 kg/cm 2  to seal tissue. The perforating strips  645   a  and  645   b  act to both grip the tissue for manipulation purposes and perforate the tissue along the center of the electrically conductive surface  612  and  622 . After electrosurgical activation of the electrically conductive surfaces  612  and  622 , the jaw members  610  and  622  are released revealing a perforated tissue line centrally-disposed between the conductive surfaces  612  and  622 . The surgeon thereafter tears the perforated tissue along the perforation to separate the two tissue halves. 
     The perforation strips  645   a  and  645   b  may be insulative or electrically conductive depending upon a particular purpose or may be made from a reactive material which heats up during electrical activation to facilitate the perforation process. 
     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 present disclosure. For example, it is contemplated that cutting mechanism may be dimensioned as a cutting wire or cutting blade that is selectively activatable by the surgeon to divide the tissue after sealing. More particularly, a wire or cutting blade is mounted within the insulator between the jaw members and is selectively energizable upon activation of a separate switch or simultaneously with the activation of the sealing switch. 
     Although the specification and drawings disclose that the electrically conductive surfaces may be employed to initially seal tissue prior to cutting tissue in one of the many ways described herein, it is also envisioned that the electrically conductive surfaces may be configured and electrically designed to perform any known bipolar or monopolar function such as electrocautery, hemostasis, and/or desiccation utilizing one or both jaw members to treat the tissue. Moreover, the jaw members in their presently described and illustrated formation may be energized or positioned to simply cut tissue without initially treating tissue which may prove beneficial during particular surgical procedures. 
     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.