Abstract:
An ultrasonic surgical instrument for dissection and coagulation of tissue is provided. The surgical instrument includes a vibration coupler supported within a housing and operably connected to an ultrasonic generator. An angled blade member is connected to the distal end of the vibration coupler to conduct high frequency vibration from the ultrasonic generator to the blade member. A clamp member is positioned adjacent to the blade member and is movable from a first position to a second approximated position. The clamp member and angled blade member combine to enhance contact between the tissue and the blade member during operation of the instrument to improve the performance of the instrument.

Description:
BACKGROUND  
         [0001]    1. Technical Field  
           [0002]    The present disclosure relates to an ultrasonic instrument for surgical use. More specifically, the present disclosure relates to an ultrasonic instrument having an angled blade member and a clamp member particularly suited for use in performing dissection and coagulation of tissue.  
           [0003]    2. Background of Related Art  
           [0004]    Ultrasonic instruments for surgical use and the benefits associated therewith are well known. For example, the use of an ultrasonic generator in conjunction with a surgical scalpel facilitates faster and easier cutting of organic tissue and accelerates blood vessel clotting in the area of the cut, i.e., accelerated coagulation. Improved cutting results from increased body tissue to scalpel contact caused by the high frequency of vibration of the scalpel blade with respect to body tissue. Improved coagulation results from heat generated by contact between the scalpel blade and the body tissue as the scalpel blade is vibrated at a high frequency. Thus, in order to reap the advantages associated with ultrasonic energy, good blade to tissue contact is important.  
           [0005]    U.S. Pat. No. 3,862,630 (“Balamuth”) discloses an ultrasonic system including an ultrasonic motor, a tool member having a working surface oriented normal to the direction of mechanical vibration generated by the ultrasonic motor, and a clamp member extending parallel to the tool member for compressing tissue against the tool member. U.S. Pat. No. 5,322,055 (“Davison”) discloses an ultrasonic surgical instrument adapted for endoscopic use having a blade and a clamp movable in relation to the blade to capture tissue therebetween. The blade and the clamp define a clamping region having a plane which is parallel to the longitudinal axis of the surgical instrument. During an endoscopic procedure, movement of the instrument is limited to movement along an axis parallel to the plane of the clamping region. Thus, no additional blade force is imposed on the body tissue as a result of movement of the instrument.  
           [0006]    Accordingly, a need exists for an improved ultrasonic surgical instrument which is easy to use and provides fast and easy cutting and improved coagulation.  
         SUMMARY  
         [0007]    In accordance with the present disclosure, an ultrasonic surgical instrument is provided for dissection and coagulation of tissue. The surgical instrument includes a housing and a vibration coupler supported within the housing operably connected to an ultrasonic generator. An angled blade member is connected to the distal end of the vibration coupler to conduct high frequency vibration to the blade member. A clamp member may be positioned adjacent to the blade member and is movable from a first position to a second approximated position to capture tissue therebetween. The clamp member and angled blade member combine to enhance contact between the tissue and the blade member during operation of the instrument to improve the performance of the instrument. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    Various preferred embodiments are described herein with reference to the drawings, wherein:  
         [0009]    [0009]FIG. 1 is a perspective view of one embodiment of the ultrasonic instrument;  
         [0010]    [0010]FIG. 2 is a side partial cross-sectional view of the ultrasonic instrument shown in FIG. 1;  
         [0011]    [0011]FIG. 2A is a side partial cross-sectional view of the proximal end of the ultrasonic instrument shown in FIG. 1 with the actuation rod biased to its distal-most position;  
         [0012]    [0012]FIG. 2B is a side partial cross-sectional view of the proximal end of the ultrasonic instrument shown in FIG. 1 further including a biasing and retaining mechanism wherein the actuation rod is retained in a retracted position;  
         [0013]    [0013]FIG. 2C is a side partial cross-sectional view of the clamp member and blade member of the ultrasonic instrument shown in FIG. 1 in the open position;  
         [0014]    [0014]FIG. 2D is a side partial cross-sectional view of the clamp member and the blade member of the ultrasonic instrument shown in FIG. 1 in the closed position;  
         [0015]    [0015]FIG. 3 is a cross-sectional view taken along section line  3 - 3  of FIG. 2;  
         [0016]    [0016]FIG. 4 is a cross-sectional view taken along section line  4 - 4  of FIG. 2C;  
         [0017]    [0017]FIG. 4A is a cross-sectional view taken along section line  4 A- 4 A of FIG. 2D;  
         [0018]    [0018]FIG. 5 is a side partial cross-sectional view of an alternate embodiment of the ultrasonic instrument;  
         [0019]    [0019]FIG. 6 is a side partial cross-sectional view of the blade member and clamp member shown in FIG. 5 with the clamp member in the open position; and  
         [0020]    [0020]FIG. 6A is a partial side cross-sectional view of the blade member and the clamp member shown in FIG. 5 in the closed position. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]    Preferred embodiments of the presently disclosed ultrasonic dissector will now be described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views.  
         [0022]    FIGS.  1 - 3  illustrate one embodiment of the presently disclosed ultrasonic instrument shown generally as  10 . Briefly, ultrasonic instrument  10  includes a substantially cylindrical outer housing  12 , preferably formed from molded housing half-sections, having an open distal end  14  and a closed proximal end  16 . The housing  12  may be formed with a gripping member  17 . The proximal end  16  of housing  12  is formed with a slot  18  dimensioned to slidably receive an actuation rod  20  which will be discussed in further detail below. A remotely located ultrasonic generator  22  is electrically connected to a transducer  23  via conventional means, such as a power cable  34 . The transducer  23  is supported within the housing and engages a vibrator coupler  24  which extends longitudinally towards the distal end  14  of housing  12 . A blade member  26  having a cutting edge  32  is provided at the distal end of the vibration coupler  24 . The blade member  26  is fixedly connected to the vibration coupler  24  or alternately integral therewith, such that the cutting edge  32  defines a plane oriented at an acute fixed angle, preferably from about 30 degrees to about 70 degrees, with respect to the longitudinal axis of the instrument.  
         [0023]    Ultrasonic generator  22  provides electrical energy having ultrasonic frequency to the transducer  23  to cause oscillation of the transducer  23  in a known manner. The transducer  23 , which may be one of a variety of electromechanical types, e.g., electrodynamic, piezoelectric, magnetostrictive, is connected in end-to-end relation to the vibration coupler  24  to cause oscillation of the vibration coupler and corresponding oscillation of angled blade member  26 .  
         [0024]    Actuation rod  20  is movably supported within housing  12  and extends from the proximal end of housing  12 , via slot  18 , through the open distal end  14  of housing  12 . Preferably, rod  20  is supported by brackets  36  which may be integrally formed with housing  12 , although any conventional support structure which allows for linear movement of the actuation rod may be used. A proximal engagement surface  38  located externally of the housing  12  facilitates selective advancement of the actuation rod  20 . Clamp  28  is connected to the distal end of the actuation rod  20  and includes clamp surface  30  which is substantially parallel to and faces cutting edge  32  of blade member  26 . The clamp  28  is movable with respect to the blade member  26  from an open position to a closed position to capture tissue between the cutting edge  32  and the clamp surface  30 . The clamp  28  may alternately be formed integral with the actuation rod  20  and may have a smooth texture although a knurled or ribbed surface may be provided to facilitate grasping of tissue or to enhance coagulation.  
         [0025]    Referring to FIGS.  2 A- 2 B, a biasing mechanism may be provided to bias the actuation rod  20  to a distal position and thus bias clamp  28  to the closed position. The biasing mechanism includes an annular ring  31  secured to or formed integrally with the is actuation rod  20  and a biasing spring  33 . Biasing spring  33  is positioned about the actuation rod  20  between bracket  36  formed on housing  12  and annular ring  31  to continuously urge the actuation rod  20  distally. (See FIG. 2A.) A retaining member  35  is pivotally secured within a slot  37  formed in the housing and is pivotable into engagement with a rack  39  formed on the actuation rod  20 . The retaining member  35  can be pivoted in the counter-clockwise direction by moving slide member  41  proximally, as viewed in FIG. 2B, to selectively retain the clamp  28  at various locations between the open and closed positions. The slide member  41  may be moved distally to disengage retaining member  35  from rack  37 , as illustrated in FIG. 2A, to clamp tissue  50  between the clamp surface  30  and the cutting edge  32 .  
         [0026]    In use, the ultrasonic instrument  10  is grasped about the proximal end of housing  12  and moved to position the cutting edge  32  adjacent tissue to be dissected and/or coagulated. The actuation rod  20  is retracted against the bias of spring  33  by pulling the engagement surface  38  of actuation rod  20  to retract clamp  28  away from blade  26  and provide access for tissue. In the open position, the clamp  28  is spaced from the blade member  26  a distance to permit easy tissue access. (See FIGS. 2C and 4.) When tissue  50  is positioned between clamp  28  and blade  26 , engagement surface  38  is released to allow biasing spring  33  to move clamp  28  to the closed position and to capture tissue  50  therebetween. (See FIGS. 2D and 4A.) The actuation rod  20  may be retained in the retracted position while the instrument  10  is positioned about tissue by pivoting retaining member  35  counter-clockwise into engagement with rack  39  formed on actuation rod  20 . (See FIG. 2B.) Clearly, other means to retain actuation rod  20  can be utilized. The ultrasonic generator  22  is energized to cause linear oscillation of the blade  26  with respect to the clamp  28  to effect dissection and/or coagulation of tissue  50 . Alternately, the actuation rod  20  may be biased proximally to the open position so the clamp is biased to the open position. In this alternate embodiment, a retaining means can be utilized to retain the clamp in the closed position.  
         [0027]    FIGS.  5 - 6 A illustrate a further embodiment of the presently disclosed ultrasonic dissector shown generally as  100 . Ultrasonic dissector  100  is provided with a pivotable clamp  128 . Briefly, ultrasonic dissector  100  includes a transducer  123  supported within a housing  112  and adapted to be connected to an ultrasonic generator  122  via power cable  134 . The transducer  123  engages a vibration coupler  124  having a blade member  126  rigidly attached, or alternatively integral, to the distal end of the coupler  124  therewith.  
         [0028]    A clamp  128  is pivotably mounted to the distal end of housing  112  about pivot member  119  such that clamp  128  extends through an open distal end  114  of housing  112 . Actuation rod  120  is supported on brackets  136  for linear movement within housing  112 . The distal end  121  of actuation rod  120  is connected to a proximal end of clamp  128  via pin  117  to translate linear advancement of the actuation rod  120  to clockwise rotation of clamp  128 .  
         [0029]    A thumb actuation member  138  is fixedly connected to actuation rod  120  by a link  143 . The link  143  extends through slot  145  formed in housing  112  to facilitate linear advancement of the thumb actuation member  138  and corresponding linear advancement of the actuation rod  120 . A biasing mechanism for biasing the actuation rod to a proximal position and a retaining mechanism to retain the actuation rod  120  in a distal position is shown in FIG. 5. Alternately, as discussed with respect to FIG. 2, the actuation rod  120  may be biased distally to maintain clamp member  128  in the closed position. In this alternate embodiment, a retaining member can be utilized to retain the clamp in the open position.  
         [0030]    More specifically referring to FIGS.  5 - 6 B, clamp member  128  of ultrasonic instrument  100  is biased to the open position by biasing spring  133 , which engages annular ring  131  to urge actuation rod  120  proximally. After the instrument  100  is properly positioned about tissue, actuation rod  120  may be advanced distally against the bias of spring  133 , via actuation member  138 , to pivot the clamp member  128  into substantial alignment with blade member  126  and capture tissue between clamp surface  130  and cutting edge  132 . (See FIG. 6A.) The retaining member  135  may be pivoted clockwise to retain the clamp member  128  and blade member  126  in the closed position. Clearly, other means to retain the clamp member  128  in the closed position can be utilized After tissue is captured between the clamp member and the blade member, the ultrasonic generator  122  may be actuated to effect dissection and/or coagulation of body tissue. As illustrated in FIG. 6A, the instrument may be moved proximally, during operation of the instrument, as indicated by arrow “B”, to increase the force applied by the cutting edge  132  on body tissue  150 .  
         [0031]    It will be understood that various modifications may be made to the embodiments disclosed herein. For example, different handle assemblies may be provided on the proximal end of the instrument to improve gripping of the instrument, e.g., pistol grip. Also, the clamp member may be biased to the open or closed position. Therefore, the above description should not be construed as limiting, but merely as exemplifications of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended thereto.