Abstract:
A bipolar electrosurgical instrument has inner and outer members each having a respective jaw member disposed at a distal end thereof. Each jaw members has right and left side surfaces and seal surface. The seal surfaces are adapted to connect to an electrical energy source such that the seal surfaces are capable of conducting bipolar energy therebetween. The inner and outer members are movable from a first position where the jaw members are disposed in spaced relation relative to one another to a second position where the jaw members are closer to one another for grasping tissue. The instrument further has a first gripping device disposed on at least one of the right and left side surfaces of one of the jaw members. The first gripping device includes tines extending therefrom dimensioned to engage and hold tissue when the jaw members are moved from the first position to the second position.

Description:
BACKGROUND  
       [0001]     1. Technical Field  
         [0002]     The present disclosure relates to an electrosurgical instrument for permanently closing epidermis and/or body tissue sections in a human or animal, and more particularly to a bipolar electrosurgical instrument having an improved gripping device. The gripping device grips, pulls together and seals epidermis and dermis tissue sections by applying a combination of pressure and electrosurgical current, while not disturbing any subcutaneous adipose tissue sections. The gripping device could also be used to oppose and fuse other types of tissue.  
         [0003]     2. Background of the Related Art  
         [0004]     Coagulation instruments are known in the art. Coagulation is defined as a process of desiccating tissue wherein the tissue cells are ruptured and dried. Vessel sealing is also known in the art. Vessel sealing is the process of liquefying the collagen in the tissue so that it crosslinks and reforms into a fused mass. Coagulation of vessels is thus sufficient to permanently close them. Small and large vessels may be sealed to assure a permanent closure.  
         [0005]     Typically, to seal vessels and/or tissue the selected tissue or vessel is placed between a first seal surface and a second seal surface of an instrument. A handle with a first looped member and a second looped member is gripped. The handle controls the seal surfaces to grip and hold the selected tissue or vessel between the first seal surface and the second seal surface. Thereafter, an electrical current is introduced through the instrument. The current is introduced by actuating an actuator to direct the current through the first seal surface through the tissue or vessel and through the second seal surface. This electrical current and the pressure imparted to the selected vessel (or tissue) causes coagulation or a liquefying of the collagen in the tissue so that that the liquefied tissue is cross-linked and the tissue reforms into a fused mass. Thereafter, the seal is completed and the instrument is withdrawn by the surgeon.  
         [0006]     Full depth skin incisions usually involve a laceration or injury where a tissue section having an epidermis section, a dermis section and a subcutaneous adipose section are all cut. Some so called “full depth” cuts or so called “full depth incisions” extend into the skin a predetermined depth. The depth is through the top epidermis section through the intermediate dermis section and also sometimes through the bottom subcutaneous adipose section.  
         [0007]     The outermost epidermis is made from a stratified squamous epithelium. These stratified squamous epithelium cells typically can withstand an amount of stress and are easier to manipulate relative to other layers. The subcutaneous adipose section, however, is made from a loose connective tissue. This loose connective tissue is more difficult to manipulate relative to the previously described stratified squamous epithelium. The cells of this type of loose connective tissue are generally separated by quite some distance relative to the previously described stratified squamous epithelium and are separated by a gel-like or gelatinous substance. The gel-like or gelatinous substance is primarily made up of collagenous and elastic fibers.  
         [0008]     This gelatinous substance is difficult to manipulate and will move and slip around if placed between, for example, the jaws of a bipolar instrument. This does not contribute to treatment of the epidermis of the full depth skin incisions using electrical current and pressure to cause coagulation or a liquefying of the epidermis so that that the liquefied tissue is cross-linked and the tissue reforms into a fused mass. A known problem is that in these applications (if it is even attempted) the subcutaneous adipose section will slide from the jaws and thus drag other tissue sections with it. This gelatinous substance of the subcutaneous adipose section impedes alignment of any lacerated edges of the epidermis and skin sections that are desired to be sealed. Thus, a known problem in the art is that the surgeon has difficultly applying the electrical current successfully to the epidermis section of such a full depth skin incision, and the lacerated edges are difficult to align and maintain in alignment once aligned between the jaws for treatment.  
         [0009]     Accordingly, there is a need for an improved gripping device for a bipolar sealing device for aligning a first lacerated edge of a first tissue component with a second lacerated edge of another tissue component. There is also a need for such a gripping device that holds and prevents the lacerated tissue component from traversing out from any alignment between the first and second tissue components. There is also a further need for such a gripping device for a bipolar sealing device that only grips a preselected optimal amount of the tissue and does not disturb other tissue in order to align the first and the second lacerated edges for coagulation.  
       SUMMARY  
       [0010]     According to a first aspect of the present disclosure, there is provided a bipolar electrosurgical instrument. The bipolar electrosurgical instrument has inner and outer members each having a respective jaw member disposed at a distal end thereof. Each jaw member has right and left side surfaces and seal surface. The seal surfaces are adapted to connect to an electrical energy source such that the seal surfaces are capable of conducting bipolar energy therebetween. The inner and outer members are movable from a first position where the jaw members are disposed in spaced relation relative to one another to a second position where the jaw members are closer to one another for grasping tissue. The instrument further has a first gripping device disposed on at least one of the right and left side surfaces of one of the jaw members. The first gripping device includes tines extending therefrom dimensioned to engage and hold tissue when the jaw members are moved from the first position to the second position.  
         [0011]     According to another aspect of the present disclosure, there is provided a bipolar electrosurgical instrument having inner and outer members. Each has a respective jaw member disposed at a distal end thereof. Each jaw member includes right and left side surfaces and seal surface. The seal surfaces are adapted to connect to an electrical energy source such that the seal surfaces are capable of conducting bipolar energy therebetween. The inner and outer members are movable from a first position wherein the jaw members are disposed in spaced relation relative to one another to a second position where the jaw members are closer to one another for grasping tissue. The instrument has a first gripping device disposed on at least one of the right and left side surfaces of one of the jaw members. The first gripping device includes a plurality of tines extending therefrom dimensioned to engage and hold tissue when the jaw members are moved from the first position to the second position. The instrument also has each of the tines with a free gripping end. The free gripping end is suitable to manipulate an epidermis section of tissue but not disturb a subcutaneous adipose tissue layer when the outer and inner members move from the first position to the second position.  
         [0012]     According to a further aspect of the present disclosure, there is provided a bipolar electrosurgical instrument. The bipolar electrosurgical instrument has inner and outer members. Each has a respective jaw member disposed at a distal end thereof. Each jaw members includes right and left side surfaces and seal surface. The seal surfaces are adapted to connect to an electrical energy source such that the seal surfaces are capable of conducting bipolar energy therebetween. The instrument has the inner and outer members movable from a first position where the jaw members are disposed in spaced relation relative to one another to a second position where the jaw members are closer to one another for grasping tissue. The instrument also has a plurality of tines disposed on at least one of the right and left side surfaces of one of the jaw members. The tines are dimensioned to engage and hold tissue when the jaw members are moved from the first position to the second position. The tines form an epidermis gripping zone. The epidermis gripping zone is suitable to grasp and retain an epidermis section of tissue and a dermis section of tissue between the seal surfaces but not contact any subcutaneous adipose tissue layer.  
         [0013]     According to another aspect of the present disclosure, there is provided a method of sealing tissue. The method has the steps of providing a bipolar instrument including inner and outer members each having a respective jaw member disposed at a distal end thereof. Each jaw members include right and left side surfaces and a seal surface. The seal surfaces are adapted to connect to an electrical energy source such that the seal surfaces are capable of conducting bipolar energy therebetween. The instrument has a first gripping device disposed on at least one of the right and left side surfaces of one of the jaw members. The first gripping device includes a plurality of tines extending therefrom dimensioned to engage and hold tissue when the jaw members are moved from the first position to the second position. The method has the steps of moving the inner and outer members from the first to second positions and engaging tissue with the gripping device. The method further has the steps of closing the first and second jaw members about tissue and activating an electrical energy source to seal tissue between the seal surfaces. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  is a view of a first tissue component with a first epidermis section, a first dermis, and a first subcutaneous adipose section adjacent to a second tissue component with a second epidermis section, a second dermis, and a second subcutaneous adipose section;  
         [0015]      FIG. 1A  is a view of a bipolar sealing instrument for tissue fusion of the present disclosure grasping and sealing the first epidermis section with the second epidermis section and not grasping any first and second subcutaneous adipose sections that disturb alignment;  
         [0016]      FIG. 2  is a close up view of the jaws of the bipolar instrument for tissue fusion having a number of tines;  
         [0017]      FIG. 3  is a perspective view of a bipolar instrument for tissue fusion;  
         [0018]      FIG. 3A  is a close up view of a first tine;  
         [0019]      FIG. 3B  is a close up of an alternative embodiment of the first tine of  FIG. 3A ;  
         [0020]      FIG. 3C  is a close up of an alternative embodiment of the first tine of  FIG. 3A ;  
         [0021]      FIG. 3D  is a close up of an alternative embodiment of the first tine of  FIG. 3A ;  
         [0022]      FIG. 3E  is a close up of an alternative embodiment of the first tine of  FIG. 3A ;  
         [0023]      FIG. 3F  is a close up of an alternative embodiment of the first tine of  FIG. 3A ;  
         [0024]      FIG. 4  is a perspective view of the bipolar sealing instrument shown partially exploded;  
         [0025]      FIG. 5  is a front view of the bipolar sealing instrument of  FIG. 3 ;  
         [0026]      FIG. 6  is a first lateral side view of the bipolar sealing instrument of  FIG. 6 .  
         [0027]      FIGS. 7 and 8  are top views of the bipolar sealing instrument of  FIG. 6 ; and  
         [0028]      FIG. 9  shows an alternative embodiment of the bipolar sealing instrument of  FIG. 6  having gripping tines extending from a distal most location of the outer and the inner jaws. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0029]     In the drawings and in the description which follows, the term “proximal”, as is traditional, will refer to the end of the apparatus which is closest to the operator, while the term “distal” will refer to the end of the apparatus which is furthest from the operator. It should be appreciated that these designation form no limitations on the present disclosure whatsoever.  
         [0030]      FIG. 1  shows a cross sectional view of a full depth incision with a first tissue component  10  and a second tissue component  10 ′. The first tissue component  10  has a first epidermis section  12 , a first dermis section  14 , and a first subcutaneous adipose section  16 . Such a full depth incision is defined as a separation of the skin, into two portions, by a sharp object through the application of an acutely directed force that extends at least though the epidermis section  12  and the dermis section  14  of the first tissue component  10 .  
         [0031]     The apparatus of the present disclosure has an improved skin grasping feature. The feature is advantageous over known surgical instruments because the apparatus and method of the present disclosure can grasp and seal or fuse the first tissue component  10  and the second tissue component  10 ′ in an improved manner over the art because the apparatus only grasps at a preselected portion of the skin.  
         [0032]     The second tissue component  10 ′ also shown in cross section in  FIG. 1  has a second epidermis section  12 ′, a second dermis section  14 ′, and a second subcutaneous adipose section  16 ′. As can be understood from the figures, the tissue components  10  and  10 ′ are shown as separated from one another by a distance marked by reference letter “d” for illustration purposes. However, in actuality some tissue components may be separated by a slight difference or gap and other tissue sections may be separated by another or different distance. Further, in another embodiment some of the tissue components (such as the first and second subcutaneous adipose sections  16  and  16 ′) may be still connected to one another while some other tissue components may be fully separated from one another by the distance “d”. Various configurations are possible and are all within the scope of the present disclosure.  
         [0033]      FIG. 1A  shows a cross sectional view of a first tissue component  10  and a second tissue component  10 ′ and bipolar sealing instrument of the present disclosure generally represented by reference number  20 . The bipolar sealing instrument  20  has a jaw member  50  with a first seal surface  24  and a jaw member  60  with a second seal surface  24 ′. The jaw members  50 ,  60  move from an opened position where the jaw members  50 ,  60  are separated relative to one another to a closed position wherein the first seal surface  24  is closer to the second seal surface  24 ′.  
         [0034]     The first and the second jaw members  50 ,  60  are selectively positionable to grasp the tissue (i.e., the first tissue component  10  and the second tissue component  10 ′) along the lateral edges between the jaw members  50 ,  60 . One significant advantage of the present disclosure over other known devices is that bipolar sealing instrument  20  aligns only the desired tissue components between the seal surfaces  24 ,  24 ′ as shown in  FIG. 1A .  
         [0035]     Once aligned, the user selectively activates the bipolar sealing instrument  20  to energize the seal surfaces  24 ,  24 ′ to apply bipolar energy across the seal surfaces  24  and  24 ′. One example of a sealing instrument is disclosed in commonly-owned U.S. Pat. Nos. 6,187,003, 6,726,686 B2, and 6,352,536 to Buysse, et al. which are all herein incorporated by reference in their entirety. Other instruments are disclosed in commonly owned PCT Patent Application Serial No. PCT/US01/11420, U.S. application Ser. No. 09/425,696 and U.S. application Ser. No. 09/178,027, which are all herein incorporated by reference in their entirety.  
         [0036]     It has been observed with a skin sealing application that it is desirable to only grip the first epidermis section  12  with the first dermis section  14  and the second epidermis section  12 ′ with the second dermis section  14 ′. As mentioned above, it has also been observed that it is not desirable to grip any portions of the first subcutaneous adipose section  16  or second subcutaneous adipose section  16 ′ for coagulating since this may affect the success of the tissue seal. More particularly, it has been observed that the first and second subcutaneous adipose sections  16 ,  16 ′ have cells which are typically not disposed close to one another relative to the other dermis sections  12 ,  12 ′,  14 ,  14 ′. Often these cells are separated by a loose gel-like connective tissue which makes the first and/or second subcutaneous adipose sections  16 ,  16 ′ difficult to handle and/or manipulate between the jaw members  50 ,  60 .  
         [0037]     Further, grasping the first and/or second subcutaneous adipose sections  16 ,  16 ′ with the first and/or second epidermis sections  12 ,  12 ′ often disturbs or misaligns the instrument&#39;s orientation which in turn may cause misalignment of the tissue structures.  
         [0038]      FIGS. 1A and 2  show the bipolar sealing instrument  20  of the present disclosure with a gripping device  100 . The gripping device  100  assists gripping the first epidermis section  12  and the first dermis section  14  with the second epidermis section  12 ′ and the second dermis section  14 ′. The gripping device  100  specifically does not grip or otherwise engage the first and second subcutaneous adipose sections  16  and  16 ′.  
         [0039]      FIG. 2  shows the bipolar sealing instrument  20  with the gripping device  100 . The gripping device  100  includes an array of tines  102  or prongs disposed on at least one side  22  of the bipolar sealing instrument  20 . The tines  102  are typically thin, pointed or needle-like projections which extend inwardly (i.e., toward tissue engaging surfaces  24 , and  24 ′) from the bipolar sealing instrument  20  and are configured to grasp epidermis section  12 ,  12 ′ of a deep skin incision. Alternatively, the gripping device  100  may have a series of protrusions, knobs, teeth, branches, connected branches, or members each collectively forming an aligned pattern on one or both sides of the bipolar sealing instrument  20  for gripping.  
         [0040]     The gripping device  100  includes a pair of opposing comb-like gripping members  114  and  114 ′ disposed on jaw members  50  and  60 , respectively. More particularly, each gripping member  114  and  114 ′ is disposed on the respective outer surface or outer side  22  and  22 ′ of each jaw member  50  and  60  such that a series of comb-like or tine elements  102  and  102 ′ common to each of the gripping members  114  and  114 ′, respectively, oppose one another for gripping and holding tissue. As best shown in  FIG. 2 , the plurality of tines  102  disposed on surface  22  is generally offset relative to the corresponding plurality of tines  102 ′ disposed on surface  22 ′ along the length of the jaw members  50  and  60 . It is envisioned that this promotes better grasping of tissue structures. Alternatively, the tines  102  and  102 ′ may register with one another along the length of the jaw members  50  and  60  depending upon a particular purpose or to achieve a particular surgical result.  
         [0041]     The gripping members  114 , and  114 ′ may be dimensioned to extend partially along the entire length of each jaw member, e.g.  50 , or may be dimensioned to extend along the entire length of the same. Alternatively, a series of gripping elements  114  may be staggered across the length of the jaw member  50  with an opposing series of gripping elements  114 ′ staggered along the opposite jaw member  60 .  
         [0042]     The gripping device  100  will contact the relevant epidermis  12 ,  12 ′ and/or dermis  14 ,  14 ′ sections and firmly grasp only the relevant epidermis/dermis  12 ,  12 ′,  14 , and  14 ′ sections while specifically not contacting other tissue sections or components that may disturb the orientation of the relevant epidermis and dermis tissue sections  12 ,  12 ′,  14 , and  14 ′. This is particularly advantageous to assist with the tissue sealing using RF electrosurgical energy. The gripping device  100  thus allows for a more precise operation of the bipolar sealing instrument  20 .  
         [0043]     In one embodiment, each of the tines  102 ,  102 ′ may be substantially “U” shaped and arranged in rows of five; however any number of tines  102  may be used for the bipolar sealing instrument  20  of the present disclosure.  
         [0044]      FIG. 3A  shows an enlarged view of an alternative configuration for the tine  102  (and/or  102 ′). The tine  102  of this particular embodiment is configured in a “U” shape with a base portion  116 . The base portion  116  connects to gripping member  114  and includes two arms  118 ,  120  which extend from the base  116 . Each arm  118  and  120  is spaced relative to one another and includes a point  122  at a distal end thereof for engaging the tissue. However, the end  122  is not limited to this configuration. In other embodiments, the ends  122  may be rectangular (end  126 ), cylindrical (end  128 ) or include a plurality of points (end  130 ) as seen in  FIGS. 3B and 3C . As shown in  FIGS. 3B and 3C , each end  122  is disposed on a single base may have differently-shaped ends  126 ,  128  and  130  respectively. Various configurations of the tines  102  are possible and within the scope of the present disclosure and have been shown in the various  FIGS. 3A through 3F  as  102   a  through  102   f.    
         [0045]     Referring to  FIG. 3A , in one embodiment, the arms  118  and  120  are straight planar members. Alternatively, the arms  118  and  120  may not be straight and instead have a curvature as shown in  FIG. 3D .  
         [0046]     Referring to  FIG. 3E , in one embodiment, the tines  102   e  may extend simply from the side  22  without any gripping member  114 . Moreover, the tines  102   a  may be configured in a longitudinal or “I” shaped configuration. In this embodiment, each of the tines  102  may simply be spaced from one another by a predetermined distance along the side  22  as shown in  FIG. 3E . Again, alternatively as shown the tines  102  in  FIG. 3F , may have a curvature to assist with grasping the relevant tissue sections and to facilitate treatment.  
         [0047]     Turning back to  FIG. 3  which shows a perspective view of one particularly simple bipolar sealing instrument  20  in an assembled state, the bipolar sealing instrument  20  has an inner member  32 ′ and an outer member  32 . The members  32  and  32 ′ are connected through an open lockbox  34  which has a gap  36  between flanges. The terms “inner” and “outer” are used to distinguish the members  32  and  32 ′, and their component parts, according to the members&#39; respective positions with respect to the open lockbox  34 , however the bipolar sealing instrument  20  is not limited to any such orientation and the inner member  32 ′ and the outer member  32  may have other configurations. The inner member  32 ′ is fitted generally within the inner surfaces of the open lockbox  34  and is captured between the flanges. The outer member  32  generally forms the outside surfaces of the open lockbox  34 . Details relating to one envisioned lockbox  34  are disclosed in commonly owned U.S. Pat. No. 6,187,003, the entire contents incorporated by references herein.  
         [0048]     The inner member  32 ′ has an inner shank  38 ′ which is operatively associated with the inner jaw  60  at a distal end thereof and has an inner ring handle  44 ′ at a proximal end thereof. Similarly, the outer member  32  has an outer shank  38  at a distal end thereof which operatively connects to the jaw member  50 , and an outer ring handle  44  at a proximal end thereof. The inner and the outer jaw members  60 , and  50  are designed to grasp tissue between the opposing seal surfaces  24 ,  24 ′.  
         [0049]     Each shank,  38  and  38 ′, has a respective ratchet stub or interlocking member  48  and  48 ′. Ratchet teeth  53  are designed to interlock in a manner that holds the inner and outer shank,  38  and  38 ′, in position. The shanks  38  and  38 ′ are deflected in the manner of a cantilever spring when the jaw members  50 ,  60  are forced together by the surgeon. The deflection of the shanks  38  and  38 ′ may produce a spring restoring force that can be opposed by interlocking the ratchet stubs or interlocking members  48 ,  48 ′.  
         [0050]     The proximal end of the jaw member  50  also includes a rectangular step  52  disposed on an inner facing surface of jaw member  50  proximal sealing surface  24 . The rectangular step  52  may be made from a thermally non-conductive material, or alternatively has a thermally non-conductive material connected thereto. The rectangular step  52  with the thermally non-conductive material does not conduct or interfere with the application of any RF electrosurgical energy to the first seal surface  24 .  
         [0051]     The proximal end of the jaw member  50  also includes rectangular step  62  disposed on an inwardly facing surface of jaw  60  proximal sealing surface  24 ′ and complementary to step  52 . The rectangular step  62  also is likewise made from a thermally non-conductive material, or alternatively has a thermally non-conductive material connected thereto. Rectangular step  62  does not conduct or interfere with the application of any RF electrosurgical energy to the seal surface  24 .  
         [0052]     In operation, the gripping members  114 ,  114 ′ contact the first and the second epidermis section  12 ,  12 ′ and the first and the second dermis sections  14 ,  14 ′ before the sections are grasped by the inner and the outer jaw members  50 ,  60 . The gripping members  114 ,  114 ′ will then contact and move the desired tissue into an alignment so the first epidermis section  12  and the second epidermis section  12 ′ align. Thereafter, the first dermis portion  14  and the second dermis portion  14 ′ align. The first dermis portion  14  and the second dermis portion  14 ′ are forced in a complementary direction between the jaw members  50 ,  60 . The desired tissue sections are introduced between the first sealing surface  24  and the second sealing surface  24 ′ for sealing by the RF electrosurgical energy.  
         [0053]      FIG. 4  shows the inner and outer member  32 ′, and  32 . Each is connected to a pole of a bipolar electrosurgical generator (not shown). Electrical connectors  51 ,  51 ′ and are located on the ring handles  44  and  44 ′ to provide a convenient point of connection with a suitable coupling. The inner and the outer members  32 ′ and  32  are formed of an electrically conductive material, such as a stainless steel. The exposed surfaces of the members  32 ′,  32 , except for the connectors  51 , and  51 ′ and the seal surfaces  24  and  24 ′, are spray coated with an insulating material. The characteristics of the bipolar electrosurgical current are determined by the design of the electrosurgical generator. Moreover, it is envisioned that other open forceps designs are also contemplated wherein the electrical connections are disposed through a single shank member and the different bipolar portions are electrically communicated through the pivot assembly. For example, commonly owned U.S. Pat. No. 6,277,117 and U.S. patent application Ser. Nos. 10/996,971 and 10/284,562 disclose different configurations or forceps which may be designed for use with the present disclosure. All of these patents and applications are herein incorporated by reference in their entirety.  
         [0054]     The generator (not shown) has an output wherein the peak-to-peak voltage will not exceed 130 Volts. This is because higher voltages can cause sparking. This sparking results in localized burning of tissue which may result in a failure of the tissue weld. The generator capable of producing high frequency output current of at least two amps (RMS). High electrical current is one aspect of the present disclosure because it heats the tissue sufficiently to melt the collagen and thus fuse the first and second epidermis sections  12 ,  12 ′. Notably, lower electrical currents will often produce weak tissue welds with low bursting strength. During operation, the bipolar sealing instrument  20  is used to grasp tissue between the seal surfaces  24  and  24 ′ using the array of tines  102 ,  102 ′. The surgeon squeezes the ring handles  44  and  44 ′ together, causing pressure to be applied to the tissue. The shanks  38  and  38 ′ are designed to maintain closure force of about 3 kg/cm 2  to about 16 kg/cm 2  between jaw members  50  and  60 .  
         [0055]     The magnitude of pressure exerted on the tissue by the seal surfaces  24 ,  24 ′ is one aspect in assuring a proper surgical outcome. Tissue pressures within a working range of about of 3 kg/cm 2  to about of 16 kg/cm 2  and, within a working range of 7 to 13 kg/cm 2  have been shown to be effective for sealing the desired first epidermis section  12  and the second epidermis section  12 ′. Tissue pressures within the range of about 4 kg/cm 2  to about 6.5 kg/cm 2  have proven to be particularly effective in sealing tissue bundles.  
         [0056]     The ratchet teeth  53  are interlocked at the appropriate ratchet setting, depending on the skin type and skin thickness. Bipolar electrosurgical current is applied through the instrument and the first and the second epidermis sections  12 ,  12 ′ are sealed. Preferably, the jaw members  50 ,  60  include one or more stop members (not shown) which provide a tissue gap of about 0.001 inches to about 0.006 inches between the vessel sealing surfaces  24 ,  24 ′ when the jaw members  50 ,  60  are closed about tissue. This is an important mechanical factor to promote tissue sealing.  
         [0057]     The jaw members  50 ,  60  have a structure and cross-section that resist bending under load. Thus the inner and the outer shanks  38 ′,  38  act as a cantilever supported beam once the seal surfaces  24 ,  24 ′ are closed. The length of this idealized cantilever beam extends from a lockbox screw  31  to the location of the respective interlocking members  48 ,  48 ′. It is possible to model each shank  38 ′,  38  as a cantilever spring having a spring constant such that each ratchet position on the teeth  53  is designed to transmit a particular closure force to the jaw members  50  and  60  against the action of the restoring force of the cantilever spring. Preferably, the closure force is produced and maintained within the above working range of 3 kg/cm 2  to 16 kg/cm 2 .  
         [0058]     The open lockbox  34  has the function of providing a pivoting joint for the inner and the outer shanks  38 ′ and  38 . In addition, the flanges provide lateral support to help maintain alignment of the jaw members  50  and  60 . Closed lockbox designs are typically used and the outer member  32  is completely captured through a slot in the inner member  32 ′.  
         [0059]     The electrically insulated pivot in the present disclosure has a shoulder washer  29  supporting the lockbox screw  31 . The shoulder washer  29  is composed of an electrically insulating material that prevents a short circuit between the members  32  and  32 ′.  
         [0060]     Referring now to a distal portion of the bipolar sealing instrument  20 , each sealing surface  24 ,  24 ′ has a radiused edge. In addition, a taper on the seal surface  24 ,  24 ′ permits a relatively constant pressure on the tissue along the length of the seal surfaces  24 ,  24 ′. The width of the seal surfaces  24  and  24 ′ is adjusted, in certain embodiments, wherein the closure force divided by the width is approximately constant along the length.  
         [0061]     In one embodiment, the seal surfaces may have a stop member  55 , made from insulating material with the stop maintaining a minimum separation of at least about 0.001 inches between the seal surfaces  24  and  24 ′, as shown in  FIG. 4 . The stop member  55  reduces the possibility of short circuits between the seal surfaces  24  and  24 ′ as well as promotes tissue sealing.  
         [0062]     In use the surgeon positions the forceps to engage the first epidermis section  12  with the first dermis section  14  and the second epidermis section  12 ′ with the second dermis section  14 ′ and they are compressed between the opposable seal surfaces  24  and  24 ′. The opposable seal surfaces  24 ,  24 ′ come together in aligned opposition due to the alignment action of the open lockbox  34 . The surgeon further deflects the shanks  38 ,  38 ′ of the members  32 ,  32 ′ to engage the ratchet stubs  48  and  48 ′. The engagement of the ratchet stubs  48 ,  48 ′ hold the shanks  38 ,  38 ′ in their deflected positions to provide a constant spring force that is transmitted as a closure force to the jaw members  50  and  60 .  
         [0063]     An electrosurgical generator (not shown) is connected to the bipolar sealing instrument  20  through connectors  51 ,  51 ′ ( FIG. 4 ) on the ring handles  44 ,  44 ′. An electrical switch is used to close a circuit between the generator and the bipolar sealing instrument  20 . Alternatively, both connectors  51 ,  51 ′ may be operatively connected to extend through ring handle  44  as shown.  
         [0064]     The switch may be a footswitch such as Valleylab&#39;s catalog number E6009, available from Valleylab Inc., Boulder Colo. The electrosurgical current flows through an electrically conductive path on each of the inner and outer members  32 ,  32 ′ between its respective electrical connector,  51 ′ or  51 , and the respective seal surfaces,  24 ,  24 ′. An electrically insulating coating substantially covers each member  32 ,  32 ′ to protect the surgeon against electrical arcs. An insulating sheath  58  may also be used to cover the members or the component parts thereof, i.e., the handles, the shanks and the outer surfaces (non-opposing surfaces) of the jaw members  50 ,  60 .  
         [0065]     It is envisioned that the outer surface of the jaw members  50 ,  60  may include a nickel-based material, a coating, a stamping, or a metal injection molding which is designed to reduce adhesion between the jaw members  50 ,  60  (or components thereof) with the surrounding tissue during activation and sealing. Other components such as the shanks  38 ,  38 ′ and the ring handles  44 ,  44 ′ are coated with the same or a different “non-stick” material. The materials are of a class of materials that provide a smooth surface to prevent mechanical tooth adhesions.  
         [0066]     It is also contemplated that the sealing surfaces  24 ,  24 ′ of the jaw members  50 ,  60 , respectively, may be manufactured from such “non-stick” materials as a nickel-chrome, a chromium nitride, a Med Coat 2000 manufactured by Electrolizing Corporation of Ohio, Inconel 600, tin-nickel, or any alloys thereof. High nickel chrome alloys and Ni200, Ni201 (about 100% Ni) may be made into electrodes or sealing surfaces by metal injection molding, stamping, machining or any like process.  
         [0067]     These materials have an optimal surface energy for eliminating sticking due in part to surface texture and susceptibility to surface breakdown due electrical effects and corrosion in the presence of biologic tissues. These materials exhibit superior non-stick qualities over stainless steel and should be used on the sealing instrument  20  in areas where the exposure to pressure and RF energy can create localized “hot spots” more susceptible to epidermis adhesion. Reducing the amount of skin that “sticks” during sealing improves the overall efficacy of the instrument. The sealing surfaces  24 ,  24 ′ may also be “coated” with one or more of the above materials to achieve the same result, i.e., a “non-stick surface”. For example, Nitride coatings (or one or more of the other above-identified materials) may be deposited as a coating on another base material (metal or nonmetal) using a vapor deposition manufacturing technique.  
         [0068]     One particular class of materials disclosed herein has demonstrated superior non-stick properties and, in some instances, superior seal quality. For example, nitride coatings which include, but not are not limited to: TiN, ZrN, TiAlN, and CrN are some materials used for non-stick purposes. One is disclosed in commonly owned U.S. patent application Ser. No. 10/284,562 which is herein incorporated by reference in its entirety.  
         [0069]     CrN has been found to be useful for non-stick purposes due to its overall surface properties and performance. Other classes of materials have also been found to reduce overall sticking. High nickel/chrome alloys with a Ni/Cr ratio of approximately 5:1 significantly reduce sticking in bipolar instrumentation. A non-stick material in this class is Inconel 600. Bipolar instrumentation having electrodes made from or coated with Ni200, Ni201 (about 100% Ni) also showed improved non-stick performance over other bipolar stainless steel electrodes.  
         [0070]     Referring now to  FIG. 9 , there is shown an alternative embodiment of the bipolar sealing instrument  20 . In this embodiment, the bipolar sealing instrument  20  has the gripping tines  102 ,  102 ′ extending longitudinally from the distal most portion of the inner and the outer jaws  50 ,  60 . Preferably, the gripping tines  102 ,  102 ′ extend from this distal most location of the inner and the outer jaws  50 ,  60  to assist with dissection of tissue. Alternatively, the gripping tines  102 ,  102 ′ may also assist with the manipulation and gripping of thin tissue for sealing by the bipolar sealing instrument  20 . The gripping tines  102 ,  102 ′ at this longitudinal distal most location of the bipolar sealing instrument  20  may have any length conducive to gripping, manipulating and/or dissecting tissue.  
         [0071]     It is to be understood that the above described embodiments are only illustrative of the application of the principles of the present disclosure. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present disclosure. The appended claims are intended to cover such modifications and arrangements.