Bipolar cutting and coagulation instrument

Abstract: A bipolar electrosurgical instrument (10) comprising a handle (12), an end effector (14) and an elongated hollow tube (16). The handle includes first (18) and second grip members (20). The end effector includes first, second and third electrodes. The first electrode (36) is substantially triangular in shape. The first electrode is adapted to pivot between an open position and a closed position. The first electrode also pivots around its proximal to distal axis and includes a coagulating surface (46) and a cutting edge (48). The second and third electrodes (38,40) are arranged substantially parallel to the first electrode when the first electrode is in the closed position. The elongated hollow tube includes a mechanism connecting the handle to the end effector such that movement of the first and second grip members relative to one another causes the first electrode to move relative to the second and third electrodes.

Description: FIELD OF THE INVENTION The present invention relates, in general, to a bipolar electrosurgical instrument for grasping, manipulating and cutting tissue and, more particularly, to a bipolar electrosurgical instrument including an end effector with a rotatable electrode. BACKGROUND OF THE INVENTION Bipolar electrosurgical instruments include bipolar shears, bipolar forceps and bipolar cutting forceps. Bipolar shears are generally used to cut tissue and are not generally useful for grasping or manipulating tissue. In bipolar-shears, wherein the tissue between the blades and distal to the cutting point is cauterized as the blades are closed. Bipolar forceps are generally used to grasp, manipulate and cauterize tissue. However, bipolar forceps are not generally useful for cutting tissue. Bipolar forceps are generally used for grasping, manipulating, cutting and coagulating tissue. In most bipolar forceps, a knife or cutting element is disposed between two opposing jaws which grasp tissue and act as electrodes. In conventional bipolar forceps the operator may cauterize the tissue between the jaws prior to cutting the tissue with a knife or other cutting element. Thus, in such bipolar forceps, the region cauterized is generally larger than the region cauterized using bipolar shears. It would, therefore, be advantageous to design a bipolar electrosurgical instrument wherein the region of cauterization may be limited as in bipolar shears or enlarged as in bipolar forceps. It would further be advantageous to design such an instrument wherein the end effector is adapted to cut tissue either before, during or after cauterizing the tissue. It would further be advantageous to design such and instrument wherein the instrument may be used to grasp and manipulate tissue. Finally, it would be advantageous to design such an instrument for use in endoscopic and other minimally invasive surgical procedures. In US-A-5,322,055 an end effector is disclosed, which comprises a clamping surface which is pivotable around a transverse axis of the instrument, and a cutting surface which is rotatable around a longitudinal axis. The effector is for use in an ultrasonic surgical instrument. SUMMARY OF THE INVENTION According to the present invention there is provided an end effector as defined in claim 1. A bipolar electrosurgical instrument incorporating the present invention may comprise a handle, an end effector and an elongated hollow tube. The handle includes first and second grip members. The end effector includes first, second and third electrodes. The first electrode may be substantially triangular in shape. The first electrode is adapted to pivot relative to the second and third electrodes about a pivot pin at the proximal end of the end effector. The first electrode pivots between an open position and a closed position. The first electrode also pivots around its proximal to distal axis. The first electrode includes at least one coagulating surface and at least one cutting edge. The second and third electrodes are arranged substantially parallel to the first electrode when the first electrode is in the closed position. The elongated hollow tube includes a mechanism connecting the handle to the end effector such that movement of the first and second grip members relative to one another causes the first electrode to move relative to the second and third electrodes. Further, according to the present invention, the coagulating surface may be one side of the triangular first electrode and the cutting edge may be formed at the intersection of the remaining two sides of the triangular electrode. The coagulating surface may be convex and may include indentations or serrations for grasping tissue. The two sides of the triangular electrode which meet to form the cutting edge may be concave in shape and form additional coagulating surfaces for coagulating tissue after it has been cut. The second and third electrodes may be electrically isolated from the first electrode and may further be electrically isolated from each other or may be electrically connected at, for example, the proximal end of the end effector. The second and third electrodes may be physically isolated from each other or they may be joined by a central region. The second and third electrodes are arranged such that the cutting edge on the first electro fits between the first and second electrodes when the end effector is in the closed position. The second and third electrodes may include indentations or serrations for griping tissue. The central region between the second and third electrodes may comprise an electrically insulating material or an electrically conductive material. The central region may include a channel adapted to receive the cutting edge of the first electrode. BRIEF DESCRIPTION OF THE DRAWINGS The novel features of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to organization and methods of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings in which: Figure 1 is a perspective view of a bipolar electrosurgical instrument according to the present invention. Figure 2 is a perspective view of an end effector for a bipolar electrosurgical instrument according to the present invention. Figure 3 is a perspective view of an end effector for a bipolar electrosurgical instrument according to the present invention wherein the end effector is in the closed position and the triangular electrode is arranged to coagulate tissue. Figure 4 is a perspective view of an end effector for a bipolar electrosurgical instrument according to the present invention wherein the end effector is in the closed position and the triangular electrode is arranged to cut tissue. Figure 5 is a top view of a rotatable attachment mechanism for an end effector for a bipolar electrosurgical instrument according to the present invention. Figure 6 is a cutaway view along line 6-6 of the end effector illustrated in Figure 5. Figure 7 is an end view of an end effector for a bipolar electrosurgical instrument according to the present invention wherein the end effector is in the closed position and the triangular electrode is arranged to coagulate tissue. Figure 8 is an end view of an end effector for a bipolar electrosurgical instrument according to the present invention wherein the end effector is in the partially closed position and the triangular electrode is arranged to cut tissue. Figure 9 illustrates an end effector for a bipolar electrosurgical instrument according to the present invention wherein the end effector is in the closed position and the triangular electrode is arranged to cut tissue. Figure 10 illustrates an end effector for a bipolar electrosurgical instrument according to the present invention wherein a central supportive region is included between two of the electrodes. DETAILED DESCRIPTION OF THE INVENTION Figure 1 illustrates a bipolar electrosurgical instrument 10 according to the present invention. In Figure 1, bipolar electrosurgical instrument 10 comprises a handle 12, an end effector 14 and an elongated hollow tube 16. Handle 12 includes first grip member 18 and second grip member 20. Electrosurgical energy is supplied to instrument 10 through electrical cord 22. Electrical cord 22 includes first wire 24, second wire 26 and bipolar plug 28 which may be connected to a conventional electrosurgical generator (not shown). Electrical cord 22 is connected to electrical connector 30 which is connected to the electrodes in end effector 14 through hollow tube 16 by wires or the like. End effector 14 includes a first jaw member 32 and a second jaw member 34. Movement of grip member 18 in direction A results in closure of end effector 14 by, for example, moving jaw 32 in direction B toward jaw 34. Figure 2 illustrates an end effector 14 for a bipolar electrosurgical instrument 10 according to the present invention. Jaw 32 includes electrode 36 which may be, for example, a triangular electrode. Jaw 34 includes electrodes 38 and 40 which may be separate as illustrated in Figure 2 or joined together as illustrated in Figure 10. Electrode 36 includes coagulating surface 46 and cutting edge 48. In the embodiment of the invention illustrated in Figure 2, electrode 36 is substantially triangular in shape when viewed from either end. Elongated hollow tube 16 includes a mechanism connecting handle 12 to jaw 32 such that movement of first grip member 18 relative to second grip member 20 causes jaw 32 to move relative to jaw 34. Electrode 36 is adapted to pivot about around its proximal to distal axis and to pivot about insulating pivot pin 44 between a open position as illustrated in Figure 2 and a closed position as illustrated in Figure 3. Electrode 32 is connected to electrical connector 30 by a wire 56 or other suitable conductor. Electrodes 38 and 40 are connected to electrical connector 30 by a wire 58 or other suitable connector. Energy from bipolar plug 28 may be applied to end effector 14 through wires 56 and 58. The application of energy to bipolar plug 28 and, thus, to end effector 14 may be controlled by, for example, using a footswitch (not shown) or other such device. End effector 14 may be opened and closed by movement of connecting rod 50. Connecting rod 50 is connected to grip member 18 at its proximal end and to lever 52 at its distal end. Movement of connecting rod 50 pivots lever 52 around insulated pivot pin 44. Lever 52 may be insulated to prevent lever 52 from shorting against tube 16. Alternately, hollow tube 16 may be constructed of an insulating material to prevent electrical shorts. Figure 3 illustrates an end effector for a bipolar electrosurgical instrument 10 according to the present invention wherein jaws 32 and 34 of end effector 14 are in the closed position and Electrode 36 is arranged to coagulate tissue. Electrodes 38 and 40 are substantially parallel to the proximal to distal axis of electrode 36 when electrode 36 is in the closed position as illustrated in Figure 3. As electrode 36 is closed along B, tissue 58 is grasped between jaw 32 and jaw 34. Tissue 58 grasped between jaws 32 and 34 may be treated by, for example, applying electrosurgical energy between jaw 32 and jaw 34. Figure 4 illustrates an end effector 14 for a bipolar electrosurgical instrument 10 according to the present invention wherein end effector 14 is in the closed position and electrode 36 is arranged to cut tissue. In the embodiment of Figure 4, electrode 36 is mounted to connector 52 by means of pivot pin 60. Electrode 36 is held in place by set screw 62. As illustrated in Figure 4, coagulation surface 46 of electrode 36 may include indentations or serrations 47 which assist in grasping and holding tissue. Serrations 47 may also be included on electrodes 38 and 40 to assist in grasping and holding tissue. Figure 5 illustrates a rotatable attachment mechanism for an end effector for a bipolar electrosurgical instrument according to the present invention. Figure 6 is a cutaway view along 6-6 of the end effector illustrated in Figure 5. In Figure 6, set screw 62 rides in channel 64, allowing electrode 36 to pivot 360° around pivot pin 60. Figure 7 is an end view of an end effector 14 for a bipolar electrosurgical instrument 10 according to the present invention wherein end effector 14 is in the closed position and electrode 36 is arranged to coagulate tissue 58. In Figure 7, coagulation surface 46 of electrode 36 holds tissue 58 in place against electrodes 38 and 40. Since tissue 58 acts as an electrical conductor, the application of electrosurgical energy to end effector 14 will result in electrical current 66 flowing from electrode 36 to electrodes 38 and 40. The electrical current will act to heat tissue 58, resulting in cauterization and/or desiccation of tissue 58. Thus, in the arrangement illustrated in Figure 7, end effector 14 may be used to cauterize tissue. End effector 14 may also be used, in the arrangement illustrated in Figure 4, to grasp and manipulate tissue without applying electrosurgical energy. In the embodiment of Figure 7, coagulating surface 46 is concave to increase the amount of tissue between coagulating surface 46 and electrodes 38 and 40 increasing the amount of tissue coagulated and enhancing the grasping characteristics of the instrument. Figure 8 is an end view of an end effector 14 for a bipolar electrosurgical instrument 10 according to the present invention wherein electrode 36 of end effector 14 is arranged to cut tissue. In Figure 8, electrosurgical energy is applied to electrode 36 such that, when electrode 36 contacts electrically conductive tissue 58, electrical current 66 will flow from electrode 36 to electrodes 38 and 40. Electrodes 38 and 40 provide a return path for the electrical current from electrode 36. Thus, tissue 58 in the region between electrodes 38 and 40 is cauterized as the end effector is closed and the tissue is cut by cutting edge 48 of electrode 36. Figure 9 illustrates an end effector 14 for a bipolar electrosurgical instrument according to the present invention wherein electrode 36 of end effector 14 has cut through tissue 58. As illustrated in Figure 9, electrical current 66 from electrode 36 continues to flow through tissue 58 for so long as electrosurgical energy is applied and tissue is positioned between electrode 36 and either of electrodes 38 or 40. Thus, even after tissue 58 is cut, the tissue in the region immediately adjacent the cut may be cauterized. Further, as end effector 14 is closed, tissue grasped by end effector 14 will be compressed between jaws 32 and 34, enhancing coagulation of the grasped tissue. In the embodiment of Figure 9, coagulating surfaces 68 are concave to facilitate the positioning and grasping of tissue between electrode 36 and electrodes 38 and 40. The inclusion of concave coagulating surfaces 68 is also advantageous in that such an arrangement increases the tissue area in contact with the electrodes. Further, the concave sides 68 of electrode 36 provide clearance to facilitate cutting by allowing cutting edge 48 to penetrate well past electrodes 38 and 40. In the present invention, electrodes 38 and 40 are electrically isolated from electrode 36 and may further be electrically isolated from each other or may be electrically connected at, for example, the proximal end of the end effector. In addition, electrodes 38 and 40 may be physically isolated from each other or they may be joined by a central region as illustrated in Figure 10. Central region 72 in Figure 10 may be a nonconductive supporting material, an insulated region of conductive material or an uninsulated region of conductive material. Central region 72 may further include a channel 74 which is adapted to receive cutting edge 48 of electrode 36. While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. Accordingly, it is intended that the invention be limited only by the scope of the appended claims.

Claims: An end effector (14) for an electrosurgical instrument (10), said end effector (14) comprising: a first electrode (36) rotatable around a first axis between a first position for performing a first function and a second position for performing a second function, said first electrode (36) being further rotatable around a second axis which is substantially perpendicular to said first axis; second and third electrodes (38, 40) wherein said second and third electrodes (38, 40) are electrically isolated from said first electrode (36), said second and third electrodes (38, 40) being arranged substantially perpendicular to said second axis, wherein said first electrode (36) is rotatable by said rotation around said second axis from an open position to a closed position in which said second and third electrodes (38, 40) are substantially parallel to said first axis. An end effector (14) according to claim 1 wherein said first electrode (36) includes a first treatment surface (46) which is substantially flat and a second treatment surface (48) which is substantially pointed. An end effector (14) according to claim 2 wherein said first electrode (36) is substantially triangular in shape. An end effector (14) according to claim 3 wherein said first treatment surface (46) is substantially convex. An end effector (14) according to claim 3 wherein said first treatment surface (46) forms a first side of said triangle and said second treatment surface (48) is positioned opposite said first surface (46) at an interface between second and third sides of said triangle. An end effector (14) according to claim 5 wherein said second and third sides are concave in shape. An end effector (14) according to claim 6 wherein said first electrode (36) is adapted to cut tissue positioned over said second and third electrodes (38, 40) when said first electrode (36) is in said first position. An end effector (14) according to claim 6 wherein said first electrode (36) is adapted to cauterize tissue positioned over said second and third electrodes (38, 40) when said first electrode (36) is in said second position. A bipolar electrosurgical instrument (10) wherein said instrument (10) comprises: a handle (12) including first and second grip members (18,20); and an end effector (14) according to any one of the preceding claims, the end effector (14) comprising: a first triangular shaped electrode (36); a coagulating surface (46) on a first side of said first electrode (36); and a cutting edge (48) on a second side of said first electrode (36); the instrument (10) further comprising an elongated hollow tub (16) including a mechanism connecting said first grip member (18) to said first electrode (36).

Inventors: AUSTIN CHARLES E, DAFFORN KENNETH R, MCELHENNEY JAY J, AUSTIN, CHARLES E., DAFFORN, KENNETH R., MCELHENNEY, JAY J.
Applicants: ETHICON ENDO SURGERY INC, ETHICON ENDO-SURGERY, INC.
Application year: 1997
Main classification: A61B18
IPC codes: A61B17, A61B18