Abstract:
A surgical instrument is provided. The surgical instrument includes an end effector assembly including first and second jaw members moveable relative to one another between a first, spaced-apart position and a second position proximate tissue, wherein, in the second position, the jaw members cooperate to define a cavity that is configured to receive tissue between the jaw members and a resilient electrically conductive sealing surface operably coupled to at least one jaw member, the resilient electrically conductive sealing surface selectively positionable from a first unflexed position to a second flexed position.

Description:
BACKGROUND 
     The present disclosure relates to surgical instruments and, more particularly, to a surgical tissue sealing for grasping, sealing and/or dividing tissue. 
     TECHNICAL FIELD 
     A forceps is a pliers-like instrument which relies on mechanical action between its jaws to grasp, clamp and constrict vessels or tissue. Electrosurgical forceps utilize both mechanical clamping action and electrical energy to affect hemostasis by heating tissue and blood vessels to coagulate and/or cauterize tissue. Certain surgical procedures require more than simply cauterizing tissue and rely on the unique combination of clamping pressure, precise electrosurgical energy control and gap distance (i.e., distance between opposing jaw members when closed about tissue) to “seal” tissue, vessels and certain vascular bundles. Typically, once a vessel is sealed, the surgeon has to accurately sever the vessel along the newly formed tissue seal. Accordingly, many vessel sealing instruments have been designed which incorporate a knife or blade member that effectively severs the tissue after forming a tissue seal. 
     SUMMARY 
     In accordance with one embodiment of the present disclosure, a surgical instrument is provided. The surgical instrument includes an end effector assembly including first and second jaw members moveable relative to one another between a first, spaced-apart position and a second position proximate tissue, wherein, in the second position, the jaw members cooperate to define a cavity that is configured to receive tissue between the jaw members and a resilient electrically conductive sealing surface operably coupled to at least one jaw member, the resilient electrically conductive sealing surface selectively positionable from a first unflexed position to a second flexed position. 
     The present disclosure also provides an end effector assembly including first and second jaw members moveable relative to one another between a first, spaced-apart position and a second position proximate tissue, wherein, in the second position, the jaw members cooperate to define a cavity that is configured to receive tissue between the jaw members, wherein at least one of the jaw members includes a resilient electrically conductive sealing surface that is selectively flexible toward tissue grasped between the jaw members to apply a pressure to the tissue from about 3 kg/cm 2  to about 16 kg/cm 2 . 
     A method for sealing tissue is also contemplated by the present disclosure. The method includes grasping tissue between first and second jaw members moveable relative to one another between a spaced-apart position and a second position proximate tissue, wherein, in the approximated position, the jaw members cooperate to define a cavity that is configured to receive tissue grasped between the jaw members; and flexing toward the grasped tissue a resilient electrically conductive sealing surface disposed within at least one of the jaw members. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments of the present disclosure are described herein with reference to the drawings wherein: 
         FIG. 1  is a front, perspective view of an endoscopic surgical instrument configured for use in accordance with the present disclosure; 
         FIG. 2  is a front, perspective view of an open surgical instrument configured for use in accordance with the present disclosure; 
         FIG. 3A  is an enlarged, side, cross-sectional view of one embodiment of an end effector assembly configured for use with the surgical instrument of  FIG. 1  or  2  wherein jaw members of the end effector assembly are positioned about tissue; 
         FIG. 3B  is an enlarged, side, perspective view of the end effector assembly of  FIG. 3A  wherein the jaw members are shown approximating tissue under a specified tissue pressure; 
         FIG. 4A  is an enlarged, side, cross-sectional view of one embodiment of an end effector assembly configured for use with the surgical instrument of  FIG. 1  or  2  wherein jaw members of the end effector assembly are positioned about tissue; 
         FIG. 4B  is an enlarged, side, perspective view of the end effector assembly of  FIG. 4A  wherein the jaw members are shown approximating tissue under a specified tissue pressure; 
         FIG. 5A  is an enlarged, side, cross-sectional view of one embodiment of an end effector assembly configured for use with the surgical instrument of  FIG. 1  or  2  wherein jaw members of the end effector assembly are positioned about tissue; and 
         FIG. 5B  is an enlarged, side, perspective view of the end effector assembly of  FIG. 5A  wherein the jaw members are shown approximating tissue under a specified tissue pressure. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure are described in detail with reference to the drawing figures wherein like reference numerals identify similar or identical elements. As used herein, the term “distal” refers to the portion that is being described which is further from a user, while the term “proximal” refers to the portion that is being described which is closer to a user. 
     Referring now to  FIGS. 1 and 2 ,  FIG. 1  depicts a forceps  10  for use in connection with endoscopic surgical procedures and  FIG. 2  depicts an open forceps  10 ′ contemplated for use in connection with traditional open surgical procedures. For the purposes herein, either an endoscopic instrument, e.g., forceps  10 , or an open instrument, e.g., forceps  10 ′, may be utilized in accordance with the present disclosure. Obviously, different electrical and mechanical connections and considerations apply to each particular type of instrument; however, the novel aspects with respect to the end effector assembly and its operating characteristics remain generally consistent with respect to both the open and endoscopic configurations. 
     Turning now to  FIG. 1 , an endoscopic forceps  10  is provided defining a longitudinal axis “X-X” and including a housing  20 , a handle assembly  30 , a rotating assembly  70 , a trigger assembly  80  and an end effector assembly  100 . Forceps  10  further includes a shaft  12  having a distal end  14  configured to mechanically engage end effector assembly  100  and a proximal end  16  that mechanically engages housing  20 . Forceps  10  also includes electrosurgical cable  610  that connects forceps  10  to a generator (not explicitly shown) or other suitable power source, although forceps  10  may alternatively be configured as a battery powered instrument. Cable  610  includes a wire (or wires) (not explicitly shown) extending therethrough that has sufficient length to extend through shaft  12  in order to provide electrical energy to at least one of the jaw members  110  and  120  of end effector assembly  100 . 
     With continued reference to  FIG. 1 , handle assembly  30  includes fixed handle  50  and a moveable handle  40 . Fixed handle  50  is integrally associated with housing  20  and handle  40  is moveable relative to fixed handle  50 . Rotating assembly  70  is rotatable in either direction about a longitudinal axis “X-X” to rotate end effector  100  about longitudinal axis “X-X.” Housing  20  houses the internal working components of forceps  10 . 
     End effector assembly  100  is shown attached at a distal end  14  of shaft  12  and includes a pair of opposing jaw members  110  and  120 . Each of jaw members  110  and  120  includes an electrically conductive tissue sealing surface  112 ,  122 , respectively. End effector assembly  100  is designed as a unilateral assembly, i.e., where jaw member  120  is fixed relative to shaft  12  and jaw member  110  is moveable about pivot  103  relative to shaft  12  and fixed jaw member  120 . However, end effector assembly  100  may alternatively be configured as a bilateral assembly, i.e., where both jaw member  110  and jaw member  120  are moveable about a pivot  103  relative to one another and to shaft  12 . In some embodiments, a knife assembly (not explicitly shown) is disposed within shaft  12  and a knife channel (not explicitly shown) is defined within one or both jaw members  110 ,  120  to permit reciprocation of a knife blade (not explicitly shown) therethrough, e.g., via activation of trigger  82  of trigger assembly  80 . The particular features of end effector assembly  100  will be described in greater detail hereinbelow. 
     Continuing with reference to  FIG. 1 , moveable handle  40  of handle assembly  30  is ultimately connected to a drive assembly (not explicitly shown) that, together, mechanically cooperate to impart movement of jaw members  110  and  120  between a spaced-apart position and an approximated position to grasp tissue disposed between sealing surfaces  112  and  122  of jaw members  110 ,  120 , respectively. As shown in  FIG. 1 , moveable handle  40  is initially spaced-apart from fixed handle  50  and, correspondingly, jaw members  110 ,  120  are in the spaced-apart position. Moveable handle  40  is depressible from this initial position to a depressed position corresponding to the approximated position of jaw members  110 ,  120 . 
     Referring now to  FIG. 2 , an open forceps  10 ′ is shown including two elongated shafts  12   a  and  12   b , each having a proximal end  16   a  and  16   b , and a distal end  14   a  and  14   b , respectively. Similar to forceps  10  ( FIG. 1 ), forceps  10 ′ is configured for use with end effector assembly  100 . More specifically, end effector assembly  100  is attached to distal ends  14   a  and  14   b  of shafts  12   a  and  12   b , respectively. As mentioned above, end effector assembly  100  includes a pair of opposing jaw members  110  and  120  that are pivotably connected about a pivot  103 . Each shaft  12   a  and  12   b  includes a handle  17   a  and  17   b  disposed at the proximal end  16   a  and  16   b  thereof. Each handle  17   a  and  17   b  defines a finger hole  18   a  and  18   b  therethrough for receiving a finger of the user. As can be appreciated, finger holes  18   a  and  18   b  facilitate movement of the shafts  12   a  and  12   b  relative to one another that, in turn, pivots jaw members  110  and  120  from an open position, wherein the jaw members  110  and  120  are disposed in spaced-apart relation relative to one another, to a closed position, wherein the jaw members  110  and  120  cooperate to grasp tissue therebetween. 
     A ratchet  30 ′ may be included for selectively locking the jaw members  110  and  120  relative to one another at various positions during pivoting. The ratchet  30 ′ may include graduations or other visual markings that enable the user to easily and quickly ascertain and control the amount of closure force desired between the jaw members  110  and  120 . 
     With continued reference to  FIG. 2 , one of the shafts, e.g., shaft  12   b , includes a proximal shaft connector  19  which is designed to connect the forceps  10 ′ to a source of energy such as an electrosurgical generator (not explicitly shown). Proximal shaft connector  19  secures an electrosurgical cable  610 ′ to forceps  10 ′ such that the user may selectively apply electrosurgical energy to the electrically conductive sealing surfaces  112  and  122  ( FIG. 1 ) of jaw members  110  and  120 , respectively, as needed. 
     Forceps  10 ′ may further include a knife assembly (not explicitly shown) disposed within either of shafts  12   a ,  12   b  and a knife channel (not explicitly shown) defined within one or both jaw members  110 ,  120  to permit reciprocation of a knife blade (not explicitly shown) therethrough. 
     Turning now to  FIGS. 3A and 3B , jaw members  110  and  120  include jaw housings  111  and  121 , respectively. The end effector assembly  100 , including jaw members  110  and  120  is configured for use with either instrument  10  or instrument  10 ′, discussed above, or any other suitable surgical instrument. However, for purposes of simplicity and consistency, end effector assembly  100  will be described hereinbelow with reference to instrument  10  only. 
     As shown in  FIGS. 3A-3B , the jaw member  110  includes a resilient electrically conductive sealing surface  212 . In some embodiments, both of the jaw members  110  and  120  may include a resilient conductive sealing surface. The sealing surface  212  may be formed as a conductive plate electrode having a freely movable proximal end  214  and a distal end  216 . The sealing surface  212  is coupled to a distal end  113  of the jaw housing  111  at its distal end  216 . The sealing surface  212  is supported within the jaw housing  111  of the jaw member  110  by a support member  218 , which is not coupled thereto and prevents the sealing surface  212  from flexing inwardly. 
     The sealing surface  212  may be formed from any suitable reversibly resilient conductive material including, but not limited to, medical grade metals and plating materials, such as stainless steel, titanium, aluminum, nickel, alloys and combinations thereof. In some embodiments, the sealing surface  212  may be formed from a non-conductive material that includes a layer of a resilient, electrically conductive material formed from the metals described above. Suitable non-conductive materials include, but not limited to, plastic, carbon fiber, and combinations thereof. The non-conductive material also includes a layer of an elastic, electrically conductive material formed from the metals described above. The term “reversibly resilient” as used herein denotes that the material retains its shape after application of force below the elasticity limit (e.g., amount of pressure that irreversibly deforms the material) that is sufficient to bend the material. The term “medical grade” as used herein denotes a material that is chemically unreactive when brought in physical contact with tissue. 
     During operation, the jaw members  110  and  120  are brought into the approximated position to proximate tissue T disposed between sealing surfaces  212  and  122  of jaw members  110 ,  120 , respectively. Thereafter, the sealing surface  212  is brought into further contact with the tissue T to apply pressure thereto. More particularly, forceps  10  (or  10 ′) includes an actuation member  130  that is longitudinally movable (e.g., by actuating the movable handle  40  and/or the trigger  80 ) within the jaw member  110 . The actuation member  130  includes an abutment surface  132  disposed at a distal end thereof that comes in contact with the proximal end  214  of the sealing surface  212 , thereby causing the sealing surface  212  to flex downward toward the tissue T. As described above, the sealing surface  212  is prevented from flexing upwardly (e.g., into the jaw housing  111 ) by the support member  218 . The longitudinal travel distance of the actuation member  130  in the distal direction may be limited to achieve a desired compression of the sealing surface  212 . 
     The longitudinal travel distance of the actuation member  130  in the distal direction is proportional to the pressure applied by the sealing surface  212 . In particular, the pressure applied may be adjusted as a function of the travel distance of the actuation member  130  and the elasticity of the sealing plate  212 . In one embodiment, the sealing surface  212  is configured to apply a predetermined amount of pressure to the tissue T from about 3 kilograms per centimeter (kg/cm 2 ) to about 16 kg/cm 2 . In other embodiments, from about 7 kg/cm 2  to about 12 kg/cm 2 . This may be controlled by adjusting one or more of the following parameters including, but not limited to, dimensions of the sealing surface  212 , material (e.g., tensile) properties of the sealing surface  212 , and/or the travel distance of the actuation member  130 . The sealing surface  212  may include a width of from about 0.25 millimeters (mm) to about 25 mm, a length of from about 1 mm to about 100 mm, and a thickness of from about 0.002 mm to about 2.5 mm. The sealing surface  212  may have an elasticity expressed as a tensile or Young&#39;s modulus from about 69 GPa (gigapascals) to about 300 GPa. 
     In some embodiments, the sealing surface  212  may be configured to snap into engagements with the tissue T when pressure is applied to the proximal end  214 . In this instance, the sealing surface  212  is configured to apply a specific pressure against the tissue T from about 3 kg/cm 2  to about 16 kg/cm 2 . In other embodiments from about 7 kg/cm 2  to about 12 kg/cm 2 . 
     With reference to  FIGS. 4A and 4B , another embodiment of the end effector assembly  300  is shown. The end effector  300  is substantially similar to the end effector  100  and is configured for use with either instrument  10  or instrument  10 ′, discussed above, or any other suitable surgical instrument. However, for purposes of simplicity and consistency, end effector assembly  300  will be described hereinbelow with reference to instrument  10  only. 
     The end effector  300  includes jaw members  310  and  320  having jaw housings  311  and  321 , respectively. The jaw member  310  includes a resilient electrically conductive sealing surface  312 . In some embodiments, both of the jaw members  310  and  320  may include a resilient conductive sealing surface. The sealing surface  312  may be formed as a conductive plate electrode having a freely movable proximal end  314  and a distal end  316 . The sealing surface  312  is coupled to a distal end  313  of the jaw housing  311  at its distal end  316 . The sealing surface  312  is supported within the jaw housing  311  of the jaw member  310  by a support member  318 , which is not coupled thereto and prevents the sealing surface  312  from flexing inwardly. The sealing surfaces  312  and  322  may be formed from the same reversibly resilient materials as the sealing surfaces  212  and  122  of  FIGS. 3A and 3B . 
     During operation, the jaw members  310  and  320  are brought into the approximated position to proximate tissue T disposed between sealing surfaces  312  and  322  of jaw members  310 ,  320 , respectively. Thereafter, the sealing surface  312  is brought into further contact with the tissue T to apply pressure thereto via the actuation member  330  that is longitudinally movable (e.g., by actuating the movable handle  40  and/or the trigger  80 ) within the jaw member  310 . The actuation member  330  includes an abutment surface  332  disposed at a distal end thereof that comes in contact with the proximal end  314  of the sealing surface  312 , thereby causing the sealing surface  312  to flex downward toward the tissue T. As described above, the sealing surface  312  is prevented from flexing upwardly (e.g., into the jaw housing  311 ) by the support member  318 . The longitudinal travel distance of the actuation member  330  in the distal direction may be limited to achieve a desired compression of the sealing surface  312 . 
     The sealing surfaces  312  and  322  are precurved to allow for smaller actuation forces for flexing the sealing surface  312  downward. In particular, since the sealing surface  312  is precurved, the sealing surface  312  is more inclined to flex toward the tissue upon engagement by the actuation member  330 . The sealing surface  312  is concave with respect to the tissue T, whereas the sealing surface  322  is convex, thus, maintaining a substantially uniform gap distance between the sealing surfaces  312  and  322 . Curvature of the sealing surface  322  may be of substantially similar shape as the sealing surface  312  to allow for the tissue “T” to be evenly spread as the jaw members  310  and  320  are approximated thereabout. 
     The longitudinal travel distance of the actuation member  330  in the distal direction is proportional to the pressure applied by the sealing surface  312 . In particular, the pressure applied may be adjusted as a function of the travel distance of the actuation member  330  and the elasticity of the sealing plate  312 . In one embodiment, the sealing surface  312  is configured to apply a predetermined amount of pressure to the tissue T from about 3 kilograms per centimeter (kg/cm 2 ) to about 16 kg/cm 2 . In other embodiments, from about 7 kg/cm 2  to about 12 kg/cm 2 . This may be controlled by adjusting one or more of the following parameters including, but not limited to, dimensions of the sealing surface  312 , material (e.g., tensile) properties of the sealing surface  312 , and/or the travel distance of the actuation member  330 . The sealing surface  312  may include a width of from about 0.25 millimeters (mm) to about 25 mm, a length of from about 1 mm to about 100 mm, and a thickness of from about 0.002 mm to about 2.5 mm. The sealing surface  312  may have an elasticity expressed as a tensile or Young&#39;s modulus from about 69 GPa (gigapascals) to about 300 GPa. 
     With reference to  FIGS. 5A and 5B , another embodiment of the end effector assembly  400  is shown. The end effector  400  is substantially similar to the end effector  100  and is configured for use with either instrument  10  or instrument  10 ′, discussed above, or any other suitable surgical instrument. However, for purposes of simplicity and consistency, end effector assembly  400  will be described hereinbelow with reference to instrument  10  only. 
     The end effector  400  includes jaw members  410  and  420  having jaw housings  411  and  421 , respectively. The jaw member  410  includes a resilient electrically conductive sealing surface  412 . In some embodiments, both of the jaw members  410  and  420  may include a resilient conductive sealing surface. The sealing surface  412  may be formed as a conductive plate electrode having a proximal end  414  and a distal end  416 . The sealing surface  412  is coupled at its proximal end  414  to a proximal end  415  of the jaw housing  411  and at its distal end  416  to a distal end  413  of the jaw housing  411 . The sealing surface  412  may be supported within the jaw housing  411  of the jaw member  410  by a support member  418 , which is not coupled thereto and prevents the sealing surface  412  from flexing inwardly. The sealing surfaces  412  and  422  may be formed from the same reversibly resilient materials as the sealing surfaces  212  and  122  of  FIG. 3A and 3B . 
     The sealing surface  412  is precurved (e.g., concave) thereby putting the sealing surface  412  under a predetermined amount of strain. In embodiments, the sealing surface  422  may also be curved either in concave or convex manner with respect to the tissue T. In a convex configuration, curvature of the sealing surface  422  may be of substantially similar shape as the sealing surface  412  to allow for the tissue “T” to be evenly spread as the jaw members  410  and  420  are approximated thereabout. A concave configuration would allow the sealing surface  422  to distribute pressure exerted on the tissue similarly to the sealing surface  412 . 
     During operation, the jaw members  410  and  420  are brought into the approximated position to proximate tissue T disposed between sealing surfaces  412  and  422  of jaw members  410 ,  420 , respectively. Preloading of the sealing surface  412  allows for gradual increase in the pressure exerted on the tissue T as the pressure exerted by the jaw members  410  and  420  is partially absorbed by the sealing surface  412 . In further embodiments, the sealing surface  412  may be formed as a leaf spring. 
     In one embodiment, the sealing surface  412  is configured to apply a predetermined amount of pressure to the tissue T from about 3 kilograms per centimeter (kg/cm 2 ) to about 16 kg/cm 2 , in embodiments, from about 7 kg/cm 2  to about 12 kg/cm 2 . This may be controlled by adjusting one or more of the following parameters including, but not limited to, dimensions of the sealing surface  412 , material (e.g., tensile) properties of the sealing surface  412 , and combinations thereof. The sealing surface  412  may include a width of from about 0.25 millimeters (mm) to about 25 mm, a length of from about 1 mm to about 100 mm, and a thickness of from about 0.002 mm to about 2.5 mm. The sealing surface  412  may have an elasticity expressed as a tensile or Young&#39;s modulus from about 69 GPa (gigapascals) to about 300 GPa. 
     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. 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.