Patent Publication Number: US-2011071523-A1

Title: Vessel Sealer with Self-Aligning Jaws

Description:
BACKGROUND 
     The present disclosure relates to a surgical forceps and, more particularly, the present disclosure relates to an electrosurgical forceps that includes self-aligning jaws. 
     TECHNICAL FIELD 
     Electrosurgical forceps utilize both mechanical clamping action and electrical energy to affect hemostasis by heating tissue and blood vessels to coagulate, cauterize and/or seal tissue. As an alternative to open forceps for use with open surgical procedures, many modern surgeons use endoscopes and endoscopic instruments for remotely accessing organs through smaller, puncture-like incisions. As a direct result thereof, patients tend to benefit from less scarring and reduced healing time. 
     Endoscopic instruments are inserted into the patient through a cannula, or port, which has been made with a trocar. Typical sizes for cannulas range from three millimeters to twelve millimeters. Smaller cannulas are usually preferred, which, as can be appreciated, ultimately presents a design challenge to instrument manufacturers who must find ways to make endoscopic instruments that fit through the smaller cannulas. 
     Many endoscopic surgical procedures require cutting or ligating blood vessels or vascular tissue. Due to the inherent spatial considerations of the surgical cavity, surgeons often have difficulty suturing vessels or performing other traditional methods of controlling bleeding, e.g., clamping and/or tying-off transected blood vessels. By utilizing an endoscopic electrosurgical forceps, a surgeon can either cauterize, coagulate/desiccate and/or simply reduce or slow bleeding simply by controlling the intensity, frequency and duration of the electrosurgical energy applied through the jaw members to the tissue. Most small blood vessels, i.e., in the range below two millimeters in diameter, can often be closed using standard electrosurgical instruments and techniques. However, if a larger vessel is ligated, it may be necessary for the surgeon to convert the endoscopic procedure into an open-surgical procedure and thereby abandon the benefits of endoscopic surgery. Alternatively, the surgeon can seal the larger vessel or tissue. Typically, after a vessel or tissue is sealed, the surgeon advances a knife to sever the sealed tissue disposed between the opposing jaw members. 
     SUMMARY 
     In accordance with the present disclosure, an end effector assembly of a surgical forceps is provided. The end effector assembly includes first and second jaw members disposed in opposing relation relative to one another that are moveable from an open position to a closed position for grasping tissue therebetween. The jaw members include opposing sealing surfaces configured to grasp tissue therebetween. Each of the jaw members also includes a knife channel defined therein. Opposing sealing surfaces of the first and second jaw members are shaped complementarily to one another to align the knife channels and sealing surfaces of the first and second jaw members upon movement from the first position to the second position. 
     In another embodiment, the opposing sealing surface of the first jaw member is concave and the opposing sealing surface of the second jaw member is complementarily convex. The concave opposing sealing surface may define a radial portion having a radius from a center point of the concavity and the convex opposing sealing surface may define a radial portion having a radius from a center point of the convexity wherein the radius of the concavity is substantially equal to the radius of the convexity. 
     In yet another embodiment, each opposing sealing surface angles inwardly from opposite longitudinal edges of the opposing sealing surface. The opposing sealing surfaces angle in the same direction with respect to a horizontal axis defined therethrough such that the jaw members are forced into alignment upon movement from the first position to the second position. 
     In another embodiment, the end effector assembly further includes one or more stop member disposed on the sealing surface of at least one of the jaw members. 
     A surgical forceps is also provided in accordance with the present disclosure that embodies a housing having at least one shaft attached thereto and an end effector assembly disposed at a distal end thereof. The end effector assembly includes first and second jaw members disposed in opposing relation relative to one another. One (or both) of the jaw members is moveable from an open position to a closed position for grasping tissue therebetween. The jaw members include opposing sealing surfaces configured to grasp tissue therebetween, each of the opposing sealing surfaces having a knife channel defined therein. A knife assembly is disposed within the shaft having a knife blade configured to translate distally from the shaft at least partially through the knife channels to cut tissue disposed between the jaw members. The opposing sealing surfaces of the first and second jaw members are shaped complementarily to one another to align the first and second jaws members upon movement from the first position to the second position. 
     In another embodiment, the surgical forceps includes at least one handle that moves the jaw members between the first and second positions. 
     In yet another embodiment, at least one of the jaw members is adapted to connect to an electrosurgical energy source to communicate energy to tissue disposed between the jaw members. 
     In still yet another embodiment in accordance with the present disclosure, a surgical forceps is provided. The forceps includes a housing having a shaft attached thereto. The shaft has an end effector assembly disposed at a distal end thereof. The end effector assembly includes first and second jaw members disposed in opposing relation relative to one another. One or both of the jaw members is moveable from an open position to a closed position for grasping tissue therebetween. The jaw members include opposing sealing surfaces configured to grasp tissue therebetween. The opposing sealing surface of the first jaw member is concave and the opposing sealing surface of the second jaw member is complementarily convex. The complementary-shaped sealing surfaces operate to align the first and second jaws members upon movement from the first position to the second position. 
     In another embodiment according to the present disclosure, a surgical forceps is provided. The forceps includes a housing having a shaft attached thereto. The shaft has an end effector assembly disposed at a distal end thereof. The end effector assembly includes first and second jaw members disposed in opposing relation relative to one another. One or both of the jaw members is moveable from an open position to a closed position for grasping tissue therebetween. The jaw members, which define a horizontal axis therethrough, include opposing sealing surfaces configured to grasp tissue therebetween. Each opposing sealing surface angles inwardly from opposite longitudinal edges of the opposing sealing surface in the same direction with respect to the horizontal axis such that the jaw members are forced into alignment upon movement from the first position to the second position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments of the subject instrument are described herein with reference to the drawings wherein: 
         FIG. 1  is a top, perspective view of an endoscopic forceps shown in an open configuration and including a housing, a handle assembly, a shaft and an end effector assembly for use with the present disclosure; 
         FIG. 2  is a top, perspective view of an alternate embodiment of an endoscopic forceps, including a housing, a handle assembly, a shaft and an end effector assembly; 
         FIG. 3  is a top, perspective view of an open surgical forceps, including a handle assembly, first and second shafts and an end effector assembly for use with the present disclosure; 
         FIG. 4  is an enlarged, side, perspective view of the end effector assembly of  FIG. 1 ; 
         FIG. 5A  is a front, cross-sectional view of the jaw members in an open configuration in accordance with one embodiment of the present disclosure; 
         FIG. 5B  is a front, cross-sectional view of the jaw members of  FIG. 5A , disposed in a closed configuration; 
         FIG. 6A  is a front, cross-sectional view of the jaw members in an open configuration in accordance with another embodiment of the present disclosure; 
         FIG. 6B  is a front, cross-sectional view of the jaw members of  FIG. 6A , disposed in a closed configuration; and 
         FIG. 7  is a side, cross-sectional view of the end effector assembly showing a knife extending through the knife channels of the jaw members. 
     
    
    
     DETAILED DESCRIPTION 
     Turning now to  FIG. 1 , an endoscopic surgical forceps  10  is shown for use with various surgical procedures and generally includes a housing  20 , a handle assembly  30 , a rotating assembly  80 , a knife trigger assembly  70  and an end effector assembly  100  which mutually cooperate to grasp, seal and divide tubular vessels and vascular tissue. 
     Forceps  10  includes a shaft  12  that has a distal end  16  dimensioned to mechanically engage the end effector assembly  100  and a proximal end  14  that mechanically engages the housing  20 . The proximal end  14  of shaft  12  is received within the housing  20 . 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. 
     Forceps  10  also includes an electrosurgical cable  310  that connects the forceps  10  to a source of electrosurgical energy, e.g., a generator (not shown). Handle assembly  30  includes two movable handles  30   a  and  30   b  disposed on opposite sides of housing  20 . Handles  30   a  and  30   b  are movable relative to one another to actuate the end effector assembly  100 . 
     Rotating assembly  80  is mechanically coupled to housing  20  and is rotatable approximately 90 degrees in either direction about a longitudinal axis “A.” Rotating assembly  80 , when rotated, rotates shaft  12 , which, in turn, rotates end effector assembly  100 . Such a configuration allows end effector assembly  100  to be rotated approximately 90 degrees in either direction with respect to housing  20 . Details relating to the inner-working components of forces  10  are disclosed in commonly-owned U.S. patent application Ser. No. 11/540,335. 
     Referring now to  FIG. 2 , an alternate embodiment of an endoscopic forceps  10 ′ is shown that includes a housing  20 ′, a handle assembly  30 ′, a rotating assembly  80 ′, a trigger assembly  70 ′ and an end effector assembly  100 ′. Forceps  10 ′ further includes a shaft  12 ′ having a distal end  16 ′ configured to mechanically engage end effector assembly  100 ′ and a proximal end  16 ′ that mechanically engages housing  20 ′. Forceps  10 ′ also includes electrosurgical cable  310 ′ that connects forceps  10 ′ to a generator (not shown). Cable  310 ′ has sufficient length to extend through shaft  12 ′ in order to provide electrical energy to at least one of jaw members  110  and  120  of end effector assembly  100 ′. 
     With continued reference to  FIG. 2 , 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  80 ′ is integrally associated with housing  20 ′ and is rotatable approximately 180 degrees in either direction about a longitudinal axis “A′.” The housing  20 ′ includes two halves that house the internal working components of the forceps  10 ′. 
     Referring now to  FIG. 3 , another alternate embodiment of a forceps  10 ″ for use with open surgical procedures is shown. Forceps  10 ″ includes end effector assembly  100 ″ that attaches to distal ends  16 ″ and  26 ″ of shafts  12 ″ and  20 ″, respectively. The end effector assembly  100 ″ includes a pair of opposing jaw members  110 ″ and  120 ″ which are pivotably connected about a pivot pin  65  and that are movable relative to one another to grasp tissue therebetween. 
     Each shaft  12 ″ and  20 ″ includes a handle  15 ″ and  17 ″, disposed at the proximal end thereof which each define a finger hole  15   a ″ and  17   a ″, respectively, therethrough for receiving a finger of the user. As can be appreciated, finger holes  15   a ″ and  17   a ″ facilitate movement of the shafts  12 ″ and  20 ″ relative to one another which, in turn, pivot the jaw members  110 ″ and  120 ″ 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. End effector assembly  100 ″ is configured in a similar manner to the end effector assembly of  FIGS. 1 and 2  above. 
     Referring now to  FIG. 4 , end effector assembly  100  is described with reference to the end effector assembly  100  show in  FIG. 1 . It is understood that all of the above end effector assemblies and forceps include similar designs and may be configured to accomplish the same purpose. End effector assembly  100  may be configured for mechanical attachment at the distal end  16  of shaft  12  of forceps  10 . End effector assembly  100  includes a pair of opposing jaw members  110  and  120 . Handles  30   a  and  30   b  of forceps  10  (see  FIG. 1 ) ultimately connect to a respective drive assembly (not shown) which, together, mechanically cooperate to impart movement of the jaw members  110  and  120  from a first, open position wherein the jaw members  110  and  120  are disposed in spaced relation relative to one another, to a second, clamping or closed position wherein the jaw members  110  and  120  cooperate to grasp tissue therebetween. Details relating to the working components of the handle assembly and drive assembly of forceps  10  are disclosed in above-mentioned U.S. patent application Ser. No. 11/540,335. 
     With reference to the example embodiment of an end effector assembly  100  shown in  FIG. 4 , opposing jaw members  110  and  120  are pivotably connected about pivot  103 . Jaw members  110  and  120  include electrically conductive sealing surfaces  112  and  122  that are dimensioned to securely engage tissue when clamped therebetween. A longitudinally-oriented knife channel  115  is defined between jaw members  110  and  120  for reciprocation of a knife  185  therethrough (see  FIG. 7 ). Knife channel  115  is defined by channels  115   a  and  115   b  (see, e.g.,  FIGS. 5A-5B ) disposed in the sealing surfaces  112  and  122 , respectively. Alternatively, knife channel  115  may be defined completely within one of the sealing surfaces  112  and  122 . Further, forceps  10  may be provided without the knife assembly (see  FIG. 7 ) and, accordingly, the sealing surfaces  112  and  122  would be configured without the knife channel  115  defined therethrough. At least one of the jaw members  110 ,  120  includes an electrically insulative stop member (or members)  750  configured to control the gap distance between sealing surfaces  112  and  122  of jaw members  110  and  120 , respectively. 
     Features of jaw members  110  and  120  will now be described with reference to  FIGS. 5A-5B  and  6 A- 6 B.  FIG. 5A  shows jaw members  110  and  120  disposed in a first, spaced-apart position. Sealing surface or opposing surface  112  of jaw member  110  has a generally concave shape. Sealing surface or opposing surface  122  of jaw member  120  has a generally convex shape. More specifically, sealing surface  112  defines an inward radial portion from opposite longitudinal sides  118   a  and  118   b  of sealing surface  112  having a radius “r” from a center point  119  of sealing surface  112 . Opposing sealing surface  122  defines an outwardly protruding convex portion extending from opposite longitudinal sides  128   a  and  128   b  of sealing surface  122  and having a radius “r” which is substantially equal to the radius “r” of the radial portion defined within jaw member  110 . Accordingly, opposing surface  112  and opposing surface  122  have complementary and, preferably non-linear shapes such that when the jaw members  110  and  120  are moved into the second, or closed position, the concave radial portion of jaw member  110  and the convex radial portion of jaw member  120  fit together, as shown in  FIG. 5B . 
     These complementary-shaped opposing surfaces  112  and  122  of  FIGS. 5A-5B  align the jaw members  110  and  120  as described hereinbelow. For example, as shown in  FIG. 5A , due to the inherent splay which results when two surfaces connected about a pivot come together, jaw members  110  and  120  may be offset from one another as the jaw members  110  and  120  move to and from open and closed positions. For example, as shown in  FIG. 5A , jaw member  110  is offset relative to jaw member  120 . As jaw members  110  and  120  move to the position shown in  FIG. 5B , jaw member  110  is forced into alignment with jaw member  120 , so that the complementary opposing surfaces  112  and  122  fit together. 
     Further, the self-aligning feature of the above-described complementary-shaped opposing surfaces  112  and  122  ensures alignment of knife channels  115   a  and  115   b  as jaw members  110  and  120  move from an open to a closed position. The alignment of knife channels  115   a  and  115   b , as shown in  FIG. 5B , allows knife blade  184  of knife  185  (see  FIG. 7 ) to more easily translate through knife channel  115  to cut tissue disposed between jaw members  110  and  120 . Additionally, the complementary concave and convex sealing surfaces  112  and  122 , respectively, provide a larger seal width as compared to linear sealing surfaces having the same overall width. On the other hand, the complementary concave and convex sealing surfaces  112  and  122 , respectively, allow jaw members  110  and  120  to be constructed with an overall smaller width, while maintaining an equal seal width as compared to jaw members having linear sealing surfaces. 
     Referring now to  FIGS. 6A-B , another embodiment of the present disclosure is shown wherein opposing surface  112 ′ of jaw member  110 ′ is angled inwardly from opposite longitudinal sides  118   a ′ and  118   b ′ of sealing surface  112 ′ toward centerline “B” of jaw member  110 ′. Opposing surface  122 ′ of jaw member  120 ′ is angled inwardly from opposite longitudinal sides  128   a ′ and  128   b ′ to centerline “C” of jaw member  120 ′. Opposing surfaces  112 ′ and  122 ′ are angled in the same direction with respect to horizontal axis “X” and thus, as in the embodiment of  FIGS. 5A-5B , opposing surfaces  112 ′ and  122 ′ of  FIGS. 6A-6B  are complementarily-shaped relative to one another. Thus, as jaw members  110 ′ and  120 ′ move from the first position to the second position, the jaw members  110 ′ and  120 ′ are forced into alignment as a result of their respective complementary shapes. Likewise, the alignment of knife channels  115   a ′ and  115   b ′ is aided by the shape of opposing surface  112 ′ and complementary opposing surface  122 ′. 
     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.