Patent Publication Number: US-9402679-B2

Title: Surgical instrument and method

Description:
RELATED APPLICATION DATA 
     This application claims priority to, and the benefit of, U.S. Provisional Application Ser. No. 61/056,207, filed on May 27, 2008, the entire disclosure of which is expressly incorporated by reference herein. 
    
    
     FIELD 
     This application relates to a surgical instrument for controlling bleeding at a surgical site, and more particularly, to a vessel harvesting device that includes a bleeding control feature. 
     BACKGROUND 
     In endoscopic vessel harvesting (EVH) surgical procedures, a long slender surgical instrument may be advanced into a tunnel next to the saphenous vein in a patient&#39;s leg, and along the saphenous vein to dissect the vessel away from adjacent tissue, and to sever side-branch vessels along the course of the vessel to be harvested. Similar technique may also be used to harvest a radial artery. 
     During the EVH procedure, vasculature in tunnel will occasionally bleed. This is a challenge for the individual performing the EVH procedure as well as for the patient. This is because blood may impair visualization of the target site during the procedure, and may cause wound complications for the patient. Existing instruments that perform EVH procedure do not provide bleeding control function to control bleeding at the tunnel. This is because the vessel harvesting instrument needs to have a low profile. Thus, providing an additional energy delivery feature in such instrument for controlling bleeding in the tunnel, which will increase the size of the instrument, is generally not desirable. Also, delivery of monopolar RF energy is not desirable for protecting a vessel. Thus, use of monopolar RF energy for bleeding control in a vessel harvesting procedure has been avoided. 
     SUMMARY 
     In accordance with some embodiments, a surgical instrument includes an elongated body having a distal end, a proximal end, and a bore extending between the distal and proximal ends, a surgical device including electrically conductive material mounted on the distal end of the body, a handle coupled to the proximal end of the elongated body, the handle including a manual control moveably mounted thereon, linkage disposed within the bore, wherein the linkage couples the manual control to the surgical device, and is configured for actuating movement of the surgical device in response to manipulation of the manual control, and a contact region of electrically conductive material disposed at the handle, wherein the contact region is electrically connected to the surgical device; wherein in a first mode of operation, the electrically conductive material of the surgical device is configured to provide heat, and in a second mode of operation, the electrically conductive material of the surgical device is configured to provide radiofrequency (RF) energy. The two modes of operation may be performed at different times, or simultaneously. 
     In accordance with other embodiments, a surgical instrument includes an elongated body having a distal end, a proximal end, and a bore extending between the distal and proximal ends, a pair of jaws for severing vessel mounted on the distal end of the body, wherein at least one of the jaws has an electrically conductive material, and a handle coupled to the proximal end of the elongated body, wherein in a first mode of operation, the electrically conductive material is for receiving energy from a direct current (DC) source, and in a second mode of operation, the electrically conductive material is for receiving energy from a RF source. 
     In accordance with other embodiments, a method for controlling bleeding at a surgical site in a patient includes inserting a surgical device into the patient, the surgical device having an electrically conductive material, supplying energy from a DC source to the electrically conductive material for performing a medical procedure, and supplying energy from a RF source to the electrically conductive material for controlling bleeding at the surgical site. By means of non-limiting examples, such medical procedure may include cutting a tissue, sealing a tissue, and/or cauterizing a tissue. In some embodiments, the medical procedure includes controlling bleeding. 
     In accordance with other embodiments, a surgical instrument includes an elongated body having a distal end, a proximal end, and a bore extending between the distal and proximal ends, and a jaw assembly located at the distal end of the elongated body, the jaw assembly having an operative element for cutting a target tissue, wherein the jaw assembly has a protrusion for abutment against a critical tissue, and the protrusion is sized so that when the protrusion is abutted against the critical tissue, the operative element is automatically placed at a desired position relative to the target tissue. In some embodiments, the target tissue includes tissue at a side branch vessel. Also, in some embodiments, the critical tissue includes tissue at a main branch vessel. 
     In accordance with other embodiments, a surgical instrument includes an elongated body having a distal end, a proximal end, and a bore extending between the distal and proximal ends, and a jaw assembly located at the distal end of the elongated body, the jaw assembly configured for cutting a side branch vessel, wherein the jaw assembly has a first jaw, a second jaw, and an electrode secured to the first jaw, wherein the second jaw has a raised portion that faces towards the first jaw, and the electrode has two side electrode portions and a middle electrode portion that is between the two side electrode portions, the raised portion of the second jaw being in alignment with the middle electrode portion. In other embodiments, instead of cutting a side branch vessel, the jaw assembly may be used to cut other tissue, such as tissue at a main branch vessel, etc. 
     In accordance with other embodiments, a surgical instrument includes an elongated body having a distal end, a proximal end, and a bore extending between the distal and proximal ends, and a jaw assembly located at the distal end of the elongated body, the jaw assembly configured for cutting tissue, wherein the jaw assembly has a first jaw, a second jaw, and an electrode secured to the first jaw, wherein the electrode has two side electrode portions and a middle electrode portion that is between the two side electrode portions, the electrode is planar and extends beyond an edge of the first jaw, and the electrode is insulated by a non-conductive portion of the first jaw. 
     Other and further aspects and features will be evident from reading the following detailed description of the embodiments, which are intended to illustrate, not limit, the invention. 
    
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
       The drawings illustrate the design and utility of embodiments, in which similar elements are referred to by common reference numerals. These drawings are not necessarily drawn to scale. In order to better appreciate how the above-recited and other advantages and objects are obtained, a more particular description of the embodiments will be rendered, which are illustrated in the accompanying drawings. These drawings depict only typical embodiments and are not therefore to be considered limiting of its scope. 
         FIG. 1  illustrates a surgical instrument in accordance with some embodiments; 
         FIGS. 2-4  are partial perspective views of a contact ring on a handle, particularly showing the contact ring being engaged at various angular orientations with an electrode of an RF source of energy to provide cauterization at the distal end of the instrument; 
         FIG. 5  is a partial perspective view of a surgical instrument that includes a thumb switch for delivering RF energy in accordance with other embodiments; 
         FIGS. 6 and 7  are partial perspective views of another surgical instrument that includes a port for receiving RF energy supplied by another instrument in accordance with some embodiments; 
         FIG. 8  is a partial perspective view of a pair of jaws at a distal end of a surgical instrument, wherein the jaws are being operated as a monopolar electrode in accordance with some embodiments; 
         FIG. 9A  is a partial perspective view of a pair of jaws in accordance with some embodiments; 
         FIG. 9B  shows the device of  FIG. 9A , showing that part of the device is covered by an insulative layer; 
         FIG. 10A  is a cross sectional view of the pair of jaws of  FIG. 9A  in accordance with some embodiments; 
         FIG. 10B  is a cross sectional view of the pair of jaws of  FIG. 9A , showing the jaws being used to cut a side branch vessel; 
         FIGS. 11 a    and  11 B are partial views of a handle showing its internal operational mechanisms at a proximal end of a surgical instrument in accordance with some embodiments; 
         FIG. 12  is a partial exploded view of the components of a surgical instrument in accordance with some embodiments; 
         FIG. 13  illustrates a surgical instrument coupled to a DC source and a RF source in accordance with other embodiments; and 
         FIG. 14  illustrates a surgical instrument coupled to a DC source and a RF source in accordance with other embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments are described hereinafter with reference to the figures. It should be noted that the figures are not drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the embodiments. They are not intended as an exhaustive description of the invention or as a limitation on the scope of the invention. In addition, an illustrated embodiment needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated. 
       FIG. 1  illustrates a surgical instrument  9  in accordance with some embodiments. The surgical instrument  9  includes a handle  11 , an elongated body  13  having a proximal end  10  and a distal end  12 , and a surgical device  14  located at the distal end  12  of the body  13 . The proximal end  10  of the elongated body  13  is coupled to a distal end  16  of the handle  11 . As used in this specification, the term “surgical device” refers to any device or component that may be used to operate on tissue (e.g., to treat, manipulate, handle, hold, cut, heat, or energize, etc., tissue). The elongated body  14  may be rigid, or alternatively, flexible. The handle  11  includes a manual actuator  15  (e.g., a button) that is coupled to the surgical device  14  through linkage (not shown) within a bore of the body  13  for manually controlling an operation of the surgical device  14 . The handle  11  and the actuator  15  may be made from insulative material(s) such as plastic. 
     In the illustrated embodiments, the surgical device  14  includes a pair of jaws  21 ,  23  for clamping, cutting, and sealing a vessel. The jaw  21  includes an electrically conductive material  25  which faces towards the opposing jaw  23 . Alternatively, or additionally, the jaw  23  may include an electrically conductive material which faces towards jaw  21 . The electrically conductive material  25  is in a form of an electrode, and is configured to selectively provide heat or RF energy during use. As used in this specification, the term “electrode” refers to a component that is for delivering energy, such as heat energy, RF energy, etc., and thus, should not be limited to a component that delivers any particular form of energy. The electrically conductive material  25  may be Ni-chrome, stainless steel, or other metals or alloys in different embodiments. The jaws  21 ,  23  are configured to close in response to actuation (e.g., pressing, pulling, or pushing, etc.) of the button  15 , thereby clamping a vessel during use. In the illustrated embodiments, the button  15  may be further actuated (e.g., further pressed, further pulled, or further pushed, etc.) to cause the electrically conductive material  25  to provide heat, thereby cutting and sealing the clamped vessel. In particular, when the button is further actuated, the electrically conductive material  25  is electrically coupled to a DC source  30 , which provides a current to the electrically conductive material (electrode)  25 , thereby heating the electrode  25 . After the vessel is cut and sealed, the button  15  may be de-actuated to open the jaws  21 ,  23 , thereby stopping the delivery of heat. The mechanical linkage for translating operation of the button  15  into closing and opening of the jaws  21 ,  23  may be implemented using cables, shafts, gears, or any of other mechanical devices that are known in the art. 
     In the illustrated embodiments, the handle  11  also includes an electrical contact region  17  that is in a form of a ring located near the distal end  16  of the handle  11 . The contact region  17  is electrically coupled to the electrically conductive material  25  at the surgical device  14 , and is configured (e.g., shaped, sized, and positioned) for receiving RF energy from a RF source. In some embodiments, the contact region  17  is electrically connected to the electrode  25  via electrical line that may be housed within a wall of the elongated body  13 , or that may be in a form of a cable that is housed within the bore of the elongated body  13 . In some embodiments, the elongated body  13  may include an outer layer of bioinert electrically insulative material. In other embodiments, instead of being in a form of a ring, the contact region  17  may be in a form of a small pad or other contact(s) located near the distal end  16  of the handle  11 . 
     The linkage that mechanically couples the jaws  21 ,  23  to the actuator  15  may be electrically insulated, for example, by silicone rubber, ceramic or other suitable non-electrically conductive material. This assures that high frequency energy supplied to the contact region  17  is conducted along the electric line housed by the body  13  to the electrically conductive material (electrode)  25  at jaw  21  (and/or electrode at jaw  23 ). In other embodiments, the body  13  may not include an electric line for coupling the contact region  17  to the electrode  25 . Instead, the linkage that mechanically couples the jaws  21 ,  23  to the actuator  15  may be electrically conductive, and is used to couple RF energy received at the contact region  17  to the electrode  25  at jaw  21  (and/or electrode at jaw  23 ). For example, the linkage may be slidably coupled to the contact region  17 . 
     In operation, as illustrated in the partial perspective views of  FIGS. 2-4 , the contact region  17  on the handle  11  of the surgical instrument  9  is contacted by the electrode  27  of an electrosurgical RF probe (e.g., a conventional BOVIE pencil), which is electrically coupled to a high frequency energy source (e.g., electrosurgical RF generator). The manual contact of the contact region  17  by the electrode  27  may be effected from any convenient angle of the electrosurgical RF probe relative to the longitudinal axis of the body  13 , and at any angular orientation of the body  13  (about its longitudinal axis). This is one advantage of using a ring configuration for the contact region  17 . As illustrated in the figure, the contact region  17  allows delivering of high frequency energy from the electrosurgical RF generator to the electrosurgical RF probe, and to the electrode  25  of the surgical device  14 . A return monopolar RF electrode that may be in a form of a pad (not shown) is coupled to the skin of the patient, and is electrically connected to a terminal of the RF generator. Thus, RF energy is delivered at the electrode  25 , and is returned to the RF generator via the return monopolar RF electrode. 
       FIG. 5  illustrates a variation of the surgical instrument  9  in accordance with other embodiments. In the illustrated embodiments, instead of having a contact region that is for contact with the electrosurgical RF probe, the surgical instrument  9  includes an additional button  31  located at the handle  11 . The button  31  is thumb-actuated, and is configured to electrically couple the electrically conductive material at the surgical device  14  to a RF source, wherein the RF source is configured to provide high frequency energy to the surgical instrument  9  (i.e., to the electrically conductive material  25  at the surgical device  14 ) via cable  29 . In some embodiments, the surgical instrument  9  provides two modes of operation. In a first mode of operation, when the button  31  is actuated, the electrically conductive material  25  is electrically coupled to the RF source, which supplies RF energy to the electrically conductive material for bleeding control. Also, in the first mode of operation, when the button  31  is actuated, the electrically conductive material  25  is electrically decoupled from the DC source  30  so that current cannot be provided to the electrically conductive material from the DC source  30  for heating the electrically conductive material  25  (e.g., even if the first button  15  is actuated). In a second mode of operation, when the button  31  is de-actuated, the electrically conductive material  25  is electrically coupled to the DC source  30 , so that the DC source  30  can supply a current to the electrically conductive material  25  for heating the electrically conductive material  25 . In other embodiments, when the button  31  is de-actuated, the electrically conductive material  25  is allowed to be electrically coupled to the DC source  30  by activation of the first button  15 . 
     It should be noted that the term “first mode” does not need to be associated with supplying RF energy, and that the term “second mode” does not need to be associated with supplying heat energy. As used in this specification, the terms “first mode” and “second mode” refer to different modes. Thus, in other embodiments, the first mode of operation may be achieved by supplying heat energy, and the second mode of operation may be achieved by supplying RF energy. Also, it should be noted that the operation of the button  31  may be reversed in other embodiments. In particular, in other embodiments, actuating the button  31  would enable delivery of heat energy (and disallow delivery of RF energy), and de-actuating the button  31  would enable delivery of RF energy (and disallow delivery of heat energy). 
       FIGS. 6 and 7  illustrate another variation of the surgical instrument  9  in accordance with other embodiments. In the illustrated embodiments, instead of having a contact region that is in a form of an outer ring at/near the handle  11 , the surgical instrument  9  includes one or more connection ports  34  disposed about the periphery of the handle  11  near its distal end  16 . Each such connection port  34  includes a contact terminal configured to receive the tip of an electrosurgical RF probe  27 , and to electrically connect such probe  27  through the electrical line housed in the body  13  (or through the mechanical linkage, e.g., the actuating rod  36 , within the body  13  if the linkage is electrically conductive) to the electrically conductive material  25  at the distal end. If a plurality of ports  34  are provided circumferentially about the distal portion of the handle  11 , then the surgical instrument  9  has the advantage of allowing the RF probe  27  to make contact with a terminal no matter how the body  13  is oriented about is longitudinal axis. In the illustrated embodiments, the actuating rod  36  is mechanically linked to the manual actuator  15  in conventional manner to slidably translate within the body  13  in response to fore and aft movements of the manual actuator  15 . Translational movement of the rod  36  is linked to the jaws  21 ,  23  in conventional manner to open and close the jaws in response to movement of the manual actuator  15 . As illustrated in the embodiments, providing port(s)  34  and contact terminal(s) in the port(s)  34  is advantageous in that such configuration may prevent unintentional contact of the contact terminal(s) by the patient during use. In other embodiments, instead of providing port(s)  34  at the handle  11 , the port(s)  34  may be provided at the body  13 . 
     In the illustrated embodiments, operation of the manual actuator  15  allows selective delivery of heat energy or RF energy in different modes of operation. In some embodiments, activating the manual actuator  15  will result in closing of the jaw assembly. The activating of the manual actuator  15  will also configure an internal switch, which allows a current to be delivered to the conductive material  25  for providing heat, and prevents energy from the RF source from being delivered to the conductive material  25 . When the manual actuator  15  is de-activated, the internal switch is configured in a different way, which allows RF energy to be delivered to the conductive material  25 , and prevents energy from the DC source from being delivered to the conductive material  25 . The internal switch will be described in further details below with reference to  FIG. 11B . 
       FIG. 9A  illustrates the pair of jaws  21 ,  23  in accordance with some embodiments. As shown in the figure, the electrically conductive material  25  forms a heating element (electrode)  40  that is disposed on a surface of the jaw  21 . The heater element  40  includes two outer portions  50 ,  52 , and an inner (middle) portion  48 . The outer portions  50 ,  52  have respective outer terminals  44 ,  46  at their ends, and the middle portion  48  has an inner terminal  42  at its end. Thus, the portions  48 ,  50 ,  52  form an electrical heater circuit between the center terminal  42  and outer terminals  44 ,  46 . In the illustrated embodiments, the outer portions  50 ,  52  and the inner portion  48  function as an electrode that is configured to deliver heat in one mode of operation, and deliver RF energy in another mode of operation. In particular, in one mode of operation, the terminal  42  of the electrode  40  is electrically coupled to a first terminal of the DC source  30 , and terminals  44 ,  46  of the electrode  40  are electrically coupled to a second terminal of the DC source  30 , thereby allowing the electrode  40  to receive DC energy (e.g., for cutting and/or welding tissue). In another mode of operation, the electrode  40  is electrically coupled to a RF source for receiving RF energy (e.g., for bleeding control). The heating element  40  may be formed using a single, flat sheet of electrically conductive material (e.g., Ni-chrome alloy, such as stainless steel at an outer layer, and Ni-chrome at an inner layer). This has reliability, manufacturing and cost advantages. It also reduces the likelihood of tissue build up and entrapment during use by not creating crevices into which the tissue can migrate. Optionally, a distal end  41  of the heater element  40  may be disposed beyond the distal end of the jaw  21  (at the distal tip) to serve as an exposed RF monopolar electrode. This allows cauterization of tissue by RF energy to be performed using the distal tip of the jaw  21   
     As shown in  FIG. 9A , the jaw-operating mechanism and linkage thereof to the actuating rod  36  may be supported in a metal housing  68  that includes metal sliding pin  70  and attachment pin  72 , all covered with an insulating layer  100  ( FIG. 9B ) of flexible material such as silicone rubber, or the like, to restrict energy discharges and to isolate tissue from moving parts. Also, such insulating cover retains the sliding and attachment pins  70 ,  72  in place to obviate the need for more expensive fasteners and mechanisms. 
     During use, in the first mode of operation, current from the DC source  30  is conducted through the center terminal  42 , and flows in the middle portion  48  of the heater element  40  and in parallel through the dual outer portions  50 ,  52  of the heating element  40  to the common terminals  44 ,  46 . Thus, for heater portions  48 ,  50 ,  52  of equal thicknesses and equal widths, current density in the middle portion  48  is twice as high as the current density in each of the outer portions  50 ,  52  in response to electrical heater signal applied between terminal  42  and the common terminals  44 ,  46 . Of course, current densities in the center and outer portions  48 ,  50 ,  52  may be altered (for example, by altering the relative widths of the heater portions, by altering resistances through selection of different materials, by altering both the widths and resistances, etc.) to alter the operating temperatures thereof in response to applied electrical heater signals. In operation, the outer heater portions  50 ,  52  may operate at a temperature sufficient to weld a tissue structure (e.g., a blood vessel) grasped between the jaws  21 ,  23 , and the center heater portion  48  may operate at a higher temperature sufficient to sever the grasped tissue structure intermediate the welded segments. In the second mode of operation, the heater element  40  does not receive current from the DC source  30 . Instead, the heater element  40  operates as a RF electrode (e.g., a monopolar electrode) and delivers RF energy that is provided from the RF generator, and that is transmitted to the heater element  40  via the contact region  17 . The application of the RF energy may be used to control bleeding at tissue that is at the surgical site, e.g., tissue that is next to the vessel being harvested, or tissue next to a side branch vessel, etc. 
     Referring now to  FIG. 10A , there is shown a partial cross sectional view of the jaws  21 ,  23  that illustrates the placement of heater portions  48 ,  50 ,  52 . The jaw  21  includes a structural support  64 , and the jaw  23  includes a structural support  66 . In some embodiments, the structural supports  64 ,  66  may be made from electrically conductive material that allows the supports  64 ,  66  to function as electrical lines (e.g., for transmitting current, RF signal, etc.). The structural supports  64 ,  66  are covered by respective layers of electrically insulating material, such as rubber, polymers, silicone, polycarbonate, ceramic or other suitable insulating material. The layers may be molded separately and bonded onto the respective structural supports  64 ,  66 . Alternatively, the layers may be over-molded onto the structural supports  64 ,  66 . As shown in the figure, the jaw  23  includes a surface elevation (protrusion)  54  substantially in alignment with the middle portion  48  in order to increase the compression force applied to a tissue structure grasped by the jaws  21 ,  23  and in contact with the middle portion  48 . This promotes more efficient tissue severance, while adjacent regions  56 ,  58  of lower surface elevations on jaw  23  in alignment with the outer portions  50 ,  52  of the heater element introduce less compression force suitable for welding grasped tissue. 
     In the illustrated embodiments, the cross sections of the respective jaws  21 ,  23  are not symmetrical. Instead, jaw  21  has a protrusion  60 , and jaw  23  has a protrusion  62 . Each of the protrusions  60 ,  62  has a length so that when the protrusions  60 ,  62  abut against a main branch vessel MB, the cutting point of the side branch vessel SB is at a prescribed distance D that is spaced away from the main branch vessel MB ( FIG. 10B ). In the illustrated embodiments, the distance D is at least 1 mm, and more preferably, at least 1.5 mm. In other embodiments, the distance D may have other values, such as that which is sufficient to prevent or minimize thermal spread from electrode  40  to the main branch vessel MB being harvested. As illustrated in the embodiments, the protrusions  60 ,  62  are advantageous in that they help reduce thermal spread resulting from the cutting and sealing of the side branch vessel SB, thereby preserving the integrity of the main branch vessel MB that is being harvested. Also, the protrusions  60 ,  62  obviate the need for an operator to guess whether the cutting of the side branch vessel SB is sufficiently far (e.g., beyond a minimum prescribed spacing) from the main branch vessel MB. Instead, the operator merely abuts the protrusions  60 ,  62  of the jaw assembly against the main branch vessel MB, and the protrusions  60 ,  62  will automatically place the jaw assembly relative to the side branch vessel SB so that the side branch vessel SB is cut at a minimum prescribed distance D from the main branch vessel MB. In some cases, if the surgical instrument  9  is used to cut other types of tissue, such as nerves, organs, tendons, etc., the protrusions  60 ,  62  also provide the same benefits of preserving the integrity of tissue that is being cut, and obviating the need for a user to guess what is the appropriate margin. As shown in the figure, the protrusions  60 ,  62  diverge away from part of the side branch vessel SB. Such configuration allows part of the side branch vessel SB that is immediately next to the main branch vessel MB not to be clamped by the jaws. As a result, the end of the side branch vessel SB will fall away once it is cut. In other embodiments, the surgical instrument  9  does not need to include both protrusions  60 ,  62 . Instead, the surgical instrument  9  may include either protrusion  60  or protrusion  62 . Such configuration allows the device at the distal end of the instrument  9  to have a smaller profile, thereby allowing a user to effectively maneuver the distal device in tight tissue conditions. As shown in the figure, the heater portion  52  may protrude laterally along an outer edge of the closed jaws  21 ,  23  to serve as an RF electrode on RF signal applied thereto in a manner described herein, while the heater portion  50  is shrouded or recessed within the lateral protrusions  60 ,  62  on the jaws  21 ,  23  for more controlled emission of applied RF signal from along mainly (or only) the exposed edge of the heater portion  52 . 
     As shown in  FIG. 8 , the jaw assembly has a concave side and a convex side. In one method of use, while the jaw assembly is used to cut a side branch vessel SB, the jaw assembly is oriented so that its concave side faces towards the main branch vessel MB. The endoscope or viewing device may be placed next to the jaw assembly with the endoscope or viewing device viewing the concave side of the jaw assembly. This allows the user to better visualize the tip of the jaw assembly. Such configuration also provides a safety feature by allowing the user to know where the tips are during the vessel cutting procedure. Also as shown in  FIG. 8 , the exposed electrode portion  52  is on the convex side of the jaw assembly while the protrusions  60 ,  62  are on the concave side of the jaw assembly. The concavity provides extra spacing to protect the main branch vessel MB by keeping the distance along the side branch vessel SB even greater when it is grasped. Furthermore, having the exposed electrode  52  on the convex side creates an apex point that makes it easier to contact the side wall of the tunnel to address bleeding. In other embodiments, the protrusions  60 ,  62  may be on the convex side of the jaw assembly. In such cases, during use, the convex side of the jaw assembly would be oriented towards the main branch vessel MB, thereby ensuring that the tips of the jaw assembly are away from the main branch vessel MB to enhance protection (e.g., preventing the tip of the jaw assembly from touching or injuring the main branch vessel MB). 
     Referring now to the partial cutaway view of  FIG. 11A  and the partial view of  FIG. 11B , which shows interior components of the handle  11 . A resilient electrical contacting device  74  is disposed within the handle  11 . The contacting device  74  includes a plurality of resilient contact terminals  75  (each of which may be considered a contact region) that are aligned with respective connection ports  34 . Each port  34  allows access by a RF probe, such as a conventional BOVIE pencil, to make contact with the corresponding contact terminal  75  therein, as illustrated in  FIG. 6 . A smoke filter  76  is positioned in the forward end of the handle  11 . The filter  76  is for filtering steam/smoke generated during operation of the device (e.g., steam/smoke resulted from cutting tissue, welding tissue, and/or bleeding control) so that the steam/smoke would not interfere with the user of the surgical instrument  9 , and help improve visualization in the working site. During use, the working tunnel has a pressure differential caused by pressurized gas (e.g., CO2) such the smoke is forced out of the tunnel, into the device tip, down the shaft, and into the filter  76  of the handle  11 . The actuator rod  36  is mechanically linked in conventional manner to the manual actuator  38  (not shown in the figure for clarity) to slidably translate the rod  36  within the outer body  13  for remotely operating the jaws  21 ,  23  between open and closed positions. An electrical switch  78  is mounted in the handle  11  to be operated in conjunction with the manual actuator  38  for controlling electrical power supplied to the heater element  48 ,  50 ,  52 . In particular, the actuator  38  has a portion  92  for engagement with a lever  94  of the switch  78 . The switch  78  has a first contact (common contact)  95 , a second contact (normally-open contact)  96 , and a third contact (normally-closed contact)  97 . The first contact  95  is electrically connected to a terminal of the heating element (electrode)  40  (e.g., via a wire), and the second contact  96  is electrically connected to a first terminal of the DC source  30 . Another terminal of the heating element (electrode)  40  is electrically connected to a second terminal of the DC source  30  (e.g., via a wire). As shown in  FIG. 11B , the contact  74  is electrically connected to the third contact  97  of the electric switch  78 . Electrical switches that may be used with the handle  11  are commercially available from E-Switch, at Brooklyn Park, Minn. The handle assembly  11  is completed with a complementary half section (not shown) that snaps together with, or is otherwise attached to the illustrated half section. The handle  11  is formed of plastic material that also provides electrical insulation from RF emissions while the device  9  is connected with the RF generator in the manner as previously describe herein. In some cases, the material for construction of the handle  11  is selected so that it provides adequate strength for the handle  11  to withstand forces of the mechanisms and forces of the user interacting with the device during a procedure. 
     During use, when the actuator  38  is pushed forward (by rotating about axis  90 ) to push rod  36 , the translation motion of the rod  36  causes the jaws  21 ,  23  to open. The opened jaws  21 ,  23  can then be used to grasp tissue (e.g., side branch vessel). When the jaws  21 ,  23  are placed around target tissue, the actuator  38  may be pulled backward to pull rod  36 . The translation motion of the rod  36  causes the jaws  21 ,  23  to close, thereby gripping the target tissue. If desired, the actuator  38  may be further pulled backward to cause the portion  92  of the actuator  38  to engage the lever  94  of the electrical switch  78 . This in turn causes the first contact  95  to be electrically connected to the second contact  96  within the switch  78 , thereby supplying DC power from the DC source to the heater element (electrode)  40 . Inside the switch  78 , when the second contact  96  is electrically connected to the first contact  95 , the third contact  97  is electrically de-coupled from the first contact  95 . Thus, while DC energy is being delivered to the electrode  40  (e.g., for providing heat to cut and/or weld tissue), the contact  74  will not be able to transmit RF energy (e.g., from an electrosurgical RF probe) to the electrode  40 . The delivery of DC energy may be stopped by pushing the actuator  38  forward so that the portion  92  is disengaged from the lever  94 . When this happens, the second contact  96  is electrically disconnected from the first contact  95  inside the switch  78 , and the third contact  97  is electrically connected to the first contact  95  inside the switch  78 . Such configuration allows RF energy (from the electrosurgical RF probe delivered at the contact  74  and transmitted to the third contact  97 ) to be transmitted to the electrode  40  (e.g., for bleeding control). Note that in this mode of operation, DC energy cannot be delivered to the electrode  40  because the first and second contacts of the switch  78  is not electrically connected. 
     Referring now to  FIG. 12 , there is illustrated an exploded view of the components forming the surgical device  14 , and its attachment to the distal end of the body  13 . Specifically, the heater elements  48 ,  50 ,  52  (conductive material  25 ) are attached to jaw  21 . Both jaws  21 ,  23  are pivotally attached via pin  77  to the metal housing  68 . Pin  70  is disposed to slide within the aligned slots  79 , and within the mating angled slots  81 ,  83  in the frame-mounts of the associated jaws to effect scissor-like jaw movement between open and closed positions as the slide pin  70  is moved relative to the pivot pin  77 . Actuator rod  36  is linked to the slide pin  70 , for example, via mating elements  85 ,  87 . Axial movement of the rod  36  in one direction will cause the slide pin  70  to move towards the pin  77 , thereby opening the jaws  21 ,  23 . Axial movement of the rod  36  in the opposite direction will cause the slide pin  70  to move away from the pin  77 , thereby closing the jaws  21 ,  23 . An electrical conductor  89  connects to the inner terminal  42  of the heating element  48 ,  50 ,  52 , and the outer terminals  44 ,  46  are electrically connected in common to conductor  91 . In some embodiments, either conductor  89  or  91  may be housed within the wall or the bore of the elongated body  13 . In other embodiments, if the rod  36  is electrically conductive, either conductor  89  or  91  may be coupled to the rod  36 . In such cases, the rod  36  will be electrically coupled to one terminal of the DC source  30 , or to the contact  95  of the switch  78 , during use. During use, the conductors  89 ,  91  may be electrically coupled to terminals of the DC source  30 , which provides a current to thereby heat up the heater elements  48 ,  50 ,  52 . The center heater element  48  is configured to cut a vessel (e.g., a side branch vessel) while the outer heater elements  50 ,  52  are configured to weld (seal) the vessel. In some embodiments, parts of the surgical device  14  may be insulated via an outer insulating layer for restricting RF emissions (when the bleeding control function is used) and for isolating certain components from biologic tissue and fluids. In the illustrated embodiments, the surgical instrument  9  includes an insulative cover  100 . 
     During use of the surgical instrument  9 , the body  13  is advanced along a vessel to be harvested. In some cases, the instrument  9  may be placed into an instrument channel of a cannula, which includes a viewing device, such as an endoscope, for allowing an operator to see the distal end of the instrument  9  inside the patient. When a side branch vessel (or other target tissue) is encountered, the jaws  21 ,  23  may be used to grasp and compress the side-branch vessel in response to manual manipulation of the actuator  38 . Power is then supplied using the DC source  30  to the heater elements  48 ,  50 ,  52  (which function as resistive element that heats up in response to the delivered direct current) to effect tissue welds at tissues that are in contact with outer segments  50 ,  52 , and to effect tissue cutting at tissue that is in contact with segment  48 . 
     During the vessel harvesting procedure, if the operator notices that there is bleeding next to the vessel being harvested (e.g., at peripheral vasculature), the operator may position the electrosurgical RF probe  27  so that it is in contact with the contact region  17 / 74  at the handle  11 . This results in RF energy being supplied (or allowed to be supplied) from the attached electrosurgical RF generator. In some cases, a foot-actuated switch may be provided that allows the operator to direct RF energy from the RF generator to the RF probe  27 . The supplied RF energy from the RF generator is conducted to the electrically conductive material  25  at the distal surgical device  14 , and the energy is returned via a return electrode pad that is coupled to a skin of the patient. The electrically conductive material  25  serves as a monopole RF electrode to electrocauterize any tissue (e.g., vessel tissue or surrounding tissue) that is grasped between the jaws  21 ,  23 . Alternatively, the lateral edge of the heater element  52  that protrudes from a side of the jaw  21  may be used to cauterize bleeding area. In such cases, the jaws  21 ,  23  may or may not be closed, and may or may not be grasping any tissue. For example, in some embodiments, the operator may not be using the jaws  21 ,  23  to grasp or cut tissue. However, if the operator notices that there is bleeding at or near the surgical site, the operator may use the element  52  protruding from a side of the jaw  21  to cauterize the bleeding area (e.g., such as that shown in  FIG. 8 ). In particular, the element  52  serves as an RF monopole electrode for electrocauterizing the tissue. 
     In some embodiments, the exposed portion of the element  52  may also be used as a DC electrode for controlling bleeding. For example, the side or the tip of the element  52  that extends beyond the profile of the jaw assembly may be used to perform thermal spot cauterization by direct thermal conduction. In such cases, the element  52  may be heated up, and its exposed edge (or tip) may be used to touch tissue that is desired to be cauterized. 
     In the above embodiments, the surgical instrument  9  has been described as having contact region(s) for allowing a RF probe to make contact, thereby causing the surgical instrument  9  to deliver RF energy at its distal end. However, in other embodiments, the surgical instrument  9  may be configured to deliver RF energy without using any RF probe to make contact with it. For example, in other embodiments, the surgical instrument  9  may be coupled to the DC source  30  via a cable  200 , wherein the cable  200  is for delivering DC energy from the DC source  30  to the surgical instrument  9  ( FIG. 13 ). The cable  200  also includes circuitry for receiving RF energy from a RF source  220  that is coupled to the DC source, as shown in the figure. In one mode of operation, the DC source  30  is configured to transmit DC energy to the surgical instrument  9 . In another mode of operation, the DC source  30  is configured to allow RF source  220  to transmit RF energy to the surgical instrument  9 . The DC source  30  may include a switch for switching between two modes of operation. Alternatively, the switch may be implemented at any point along the length of the cable  200  or at the handle  11 . In some cases, a RF control, such as a button, a foot pedal, etc., may be provided, for allowing a user to direct RF energy to the surgical instrument  9 . In such cases, after the mode-switch control is activated for allowing delivery of RF energy, RF energy will not be delivered unless the RF control is actuated by the user. This provides a safety feature for preventing accidental delivery of RF energy from the RF source  220 . The RF control may be coupled to the RF source  220 , to the DC source  30 , or at any point along the RF line. In other embodiments, the RF control may also be implemented as a component at the RF source  220 , at the DC source  30 , or at the cable  200 . 
     In other embodiments, the cable  200  may be coupled to a switch box  210 . The switch box  210  is configured to receive energy from the DC source  30  and transmit it to the surgical instrument  9  in one mode of operation ( FIG. 14 ). In another mode of operation, the switch box  210  is configured to receive RF energy from a RF source  220 , and transmit the RF energy to the surgical instrument  9 . The switch box  210  may include a control for allowing a user to switch between the first and second modes of operation. Alternatively, the control for switching between modes of operation may be implemented at any point along the length of the cable  200  or at the handle  11 . In some cases, a RF control, such as a button, a foot pedal, etc., may be provided, for allowing a user to direct RF energy to the surgical instrument  9 . In such cases, after the switch box  210  is configured to deliver RF energy, RF energy will not be delivered unless the RF control is actuated by the user. This provides a safety feature for preventing accidental delivery of RF energy from the RF source  220 . The RF control may be coupled to the RF source  220 , the switch box  210 , or to any point along the length of the cable  200 . In other embodiments, the RF control may also be implemented as a component at the RF source  220 , at the switch box  210 , or at the cable  200 . 
     As illustrated in the above embodiments, the surgical instrument  9  allows delivering of heat to a remote surgical site for welding and severing vessel, and allows delivering of RF energy for cauterizing tissue to control bleeding. Such instrument is advantageous since combining heat delivery function with RF delivery function would allow a user to address two very different situations (e.g., tissue welding and bleeding control) using a single tool. Also, because many of the components in the instrument  9  that are for providing DC heating are also used for delivering RF energy, the instrument  9  maintains a low profile without any substantial increase in its size. Furthermore, the instrument  9  allows delivery of RF energy in a controlled manner, thereby protecting the vessel being harvested while allowing bleeding to be controlled. Embodiments of the instrument  9  is also advantageous in that it obviates the need for repeatedly inserting a separate bleeding control device inside the patient to control bleeding, and removing such bleeding control device from the patient, during a vessel harvesting procedure. Thus, embodiments of the surgical instrument  9  described herein allows delivery of RF energy in a way that makes it much easier to address bleeding. 
     Although the above embodiments have been described with reference to the surgical device  14  being a pair of jaws for clamping, cutting, and sealing vessel (e.g., saphenous vein, an artery, or any other vessel), in other embodiments, the surgical device  14  may have different configurations, and different functionalities. For example, in other embodiments, the surgical device  14  may be clip appliers or grasping jaws with no heating functionality, but still include one or more high frequency electrodes for delivering RF energy from RF source to control bleeding. In further embodiments, the bleeding control feature (e.g., the components for allowing RF to be delivered to the distal end of the surgical instrument) may be incorporated in any type of laparoscopic/endoscopic surgical tool. Also, in any of the embodiments described herein, the surgical instrument  9  may be used in any endoscopic procedure that requires transection of tissue with bleeding control. 
     In addition, although the above embodiments have been described with reference to delivering heat energy and RF energy in different times, in other embodiments, the surgical instrument  9  may be configured to deliver heat energy and RF energy simultaneously. For example, in other embodiments, the surgical instrument  9  may include an electrode for delivering heat energy to cut and/or seal tissue, and another electrode for delivering RF energy for bleeding control. In other embodiments, the surgical instrument  9  may include an operative element for simultaneously delivering heat and RF energy. 
     Also, although the above embodiments have been described with reference to a surgical instrument that has a bleeding control feature, in other embodiments, such bleeding control feature is optional. Thus, in any of the embodiments described herein, the surgical instrument  9  may not include the port(s)  34 , the contact region  17 /contact device  74 , and the electrical switch  78 . In addition, in any of the embodiments described herein, the jaw assembly at the distal end of the surgical instrument  9  does not need to include all of the features described herein. For example, in some embodiments, the jaw assembly does not include outer electrode portions  50 ,  52 . Instead, the jaw assembly includes one electrode strip (like the middle electrode portion  48  described above) for cutting or sealing tissue. Furthermore, in other embodiments, the jaw  23  may not have the raised portion  54 . Instead, the jaw  23  may have a flat surface that is for contacting the electrode portions  48 ,  50 ,  52 . In addition, in further embodiments, the jaws  21 ,  23  may not include the respective protrusions  60 ,  62 . Instead, the cross section of the jaw  21 / 23  may have a symmetrical configuration. In other embodiments, protrusion(s) may be provided on both sides of the jaw assembly (e.g., one or more protrusions at the concave side of the jaw assembly, and one or more protrusions at the convex side of the jaw assembly). Such configuration provides buffering on both sides of the jaw assembly, and allows for correct placement of the jaw assembly regardless of which side (the concave or convex side) of the jaw assembly is oriented towards the main branch vessel MB during use. In further embodiments, instead of the curved configuration, the jaws could be straight. Also, in any of the embodiments described herein, instead of, or in addition to, using the electrode  40  for controlling bleeding, the electrode  40  may be used for dissection or transection of tissue, such as fatty and connective tissue encountered during a vessel harvesting procedure. 
     Although particular embodiments have been shown and described, it will be understood that they are not intended to limit the present inventions, and it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present inventions. The specification and drawings are, accordingly, to be regarded in an illustrative rather than restrictive sense. The present inventions are intended to cover alternatives, modifications, and equivalents, which may be included within the spirit and scope of the present inventions as defined by the claims.