Patent Publication Number: US-2007102472-A1

Title: Electrosurgical stapling instrument with disposable severing / stapling unit

Description:
FIELD OF THE INVENT 10 N  
      The invention generally relates to surgical instruments. The invention more particularly relates to transmission and application of electrical energy in association with the use of surgical instruments to promote closure and healing of severed and stapled tissue.  
     BACKGROUND  
      Conventional surgical staplers that can be used to simultaneously make incisions in tissue and apply lines of staples on opposing sides of the incisions are known in the art. Such devices commonly include a pair of cooperating jaw members that, when employed in endoscopic or laparoscopic applications, are capable of passing through a cannula passageway. One of the jaw members typically has a staple cartridge having at least two laterally spaced rows of staples. The other jaw member defines an anvil having staple-forming pockets correspondingly aligned with the rows of staples in the staple cartridge. In addition, a knife or other cutting edge is included in the surgical stapler which is designed to cut tissue during a surgical procedure.  
      In operation of the surgical stapler, a clinician can close or clamp the jaw members to position tissue prior to firing or activation of the stapler. Once the clinician has determined that the jaw members are clamping the tissue in a desired position, then the surgical stapler can be fired by the clinician to create an incision in the tissue and at the same time staple tissue surrounding the incision. This simultaneous severing/stapling action avoids complications that often arise when the severing and stapling operations are performed sequentially and/or with different surgical tools (i.e., one device is used to sever the tissue, and then another device is used to staple the tissue).  
      In general, application of various kinds of energy in association with closing a tissue incision can promote healing, reduce the possibility of infection, and/or promote proper sealing of the incision. If assisted by the cauterizing action of electrical energy, for example, many surgical staplers could achieve better surgical results with respect to enhanced healing, improved infection resistance, and improved sealing of tissue incisions. However, the structure of many conventional surgical staplers, and the medical procedures in which they are employed, do not adequately leverage the beneficial effects of applying electrical energy to severed/stapled tissue.  
      In view of the foregoing, there is a need for improved electrosurgical instruments and electrical energy transmission systems than can more effectively and efficiently promote closure, treatment, and healing of tissue incisions created during procedures involving surgical staplers.  
     SUMMARY  
      In various embodiments of the invention, an electrical energy transmission system structured for use with a surgical severing/stapling instrument including a removably connectable disposable severing/stapling unit are provided. The energy transmission system may include an electrical power source; and, at least one electrode positioned on at least one of an anvil assembly or a cartridge assembly of the disposable severing/stapling unit. The assembly electrode may be configured to receive electrical power from the electrical power source when the disposable severing/stapling unit is removably connected to the surgical instrument. In certain embodiments, the electrical power source may include a radio frequency electrical power source providing electrical current to the assembly electrode.  
      In various embodiments of the invention, a surgical severing/stapling instrument may be provided with an electrical energy transmission system. The instrument may include a handle portion including an electrical power source and an implement portion connected to the handle portion. The implement portion may include a shaft structured for removably connecting a disposable severing/stapling unit to the implement portion. The disposable unit may include an anvil assembly and a cartridge assembly. At least one of the anvil assembly or the cartridge assembly may include at least one electrode positioned thereon, such that the assembly electrode can be configured to receive electrical power from the electrical power source when the disposable unit is removably connected to the shaft for use with the surgical instrument. 
    
    
     BRIEF DESCRIPT 10 N OF THE FIGURES  
      The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate embodiments of the invention. Together with the description of the embodiments provided herein, the drawings serve to explain the principles of the invention for those skilled in the art.  
       FIG. 1  includes a three-dimensional view of a surgical instrument provided in accordance with various embodiments of the invention;  
       FIG. 2  includes a disassembled view of portions of a surgical instrument provided in accordance with various embodiments of the invention;  
       FIG. 3  includes a three-dimensional top view of a disposable severing/stapling unit provided in accordance with various embodiments of the invention;  
       FIG. 4  includes a three-dimensional bottom view of a disposable severing/stapling unit provided in accordance with various embodiments of the invention;  
       FIG. 5  includes a top view of a staple cartridge assembly provided in accordance with various embodiments of the invention;  
       FIG. 6  includes a side view of the cartridge assembly of  FIG. 5 ;  
       FIG. 7  includes a bottom view of an anvil assembly provided in accordance with various embodiments of the invention; and,  
       FIG. 8  includes a side view of the anvil assembly of  FIG. 7 . 
    
    
     DESCRIPT 10 N  
      As applied herein, the term “tissue” may include a variety of human or animal tissues, membranes, or other organic substrates. The term “tissue” may also include any substance, substrate, or composition of matter capable of being severed, stapled or otherwise manipulated by the various embodiments of surgical stapling/severing instruments described herein.  
      With general reference to the figures, in association with various embodiments of the invention, a surgical severing/stapling instrument  10  including an electrical energy transmission system may be provided. The instrument  10  may include a handle portion  20  connected to an implement portion  22 . The implement portion  22  includes a shaft  24  which extends distally from the handle portion  20  and which can be removably connected to a disposable severing/stapling unit  26 . The disposable severing/stapling unit  26  may include a distally positioned anvil assembly  28  which is pivotally connected in the disposable unit  26  for opening/closing movement relative to a staple cartridge assembly  30 . It can be seen that the spacing between the anvil assembly  28  and the staple cartridge assembly  30  may be configured to promote effective clamping, stapling and severing of tissue during use of the surgical instrument  10  by a clinician, for example, in a medical procedure.  
      The removable connection between the disposable unit  26  and the shaft  24  may be accomplished by use of one or more push rods  32 ,  34  extending outwardly from the proximal end of the disposable severing/stapling unit  26 . The push rods  32 ,  34  may be normally resiliently biased (e.g., by action of a conventional spring configuration) in the outward position (as shown in  FIG. 2 , for example) after the disposable unit  26  is removed from the shaft  24  of the implement portion  22 . In association with connection of the disposable unit  26  to the shaft  24 , the push rods  32 ,  34  may be received in push rod depressions (such as illustrative depression  38 , shown in  FIG. 1 , for example) to promote locking of the disposable unit  26  in position with respect to the shaft  24  of the implement portion  22 . It can be seen that the push rod  32 ,  34  configuration permits ready removal of the disposable unit  26 , especially for applications wherein a new disposable unit  26  may be desirable for each successive firing of the instrument  10 . The push rod  32 ,  34  configuration also resists unwanted dislodgement of the disposable unit  26  from the shaft  24  during use and operation of the instrument  10 .  
      The handle portion  20  of the instrument  10  may include a grip  42  toward which a closure trigger  44  may be pivotally drawn by manual pressure applied by a clinician, for example, to cause clamping or closing of the anvil assembly  28  toward the cartridge assembly  30  of the disposable unit  26 . In operations involving the surgical instrument  10 , tissue may be clamped by the closing of the anvil assembly  28  toward the cartridge assembly  30 . The handle portion  20  may also include a firing trigger or other functionality that causes the instrument  10 , once the anvil assembly  28  is closed toward the cartridge assembly  30 , to substantially simultaneously staple and sever tissue clamped in the disposable unit  26 .  
      In various embodiments, the disposable unit  26  may include a lower channel  52  and an upper cover  54 . The staple cartridge assembly  30  may be received within a distal end of the lower channel  42 , as shown in  FIG. 2 . In addition, a staple cartridge  56  may be positioned in the staple cartridge assembly  30 . The staple cartridge  56  may have multiple staple holes (such as illustratively representative staple holes  58 ,  60 ,  62 ) formed therein and through which multiple staples (not shown) may be driven to staple severed tissue when the instrument  10  is fired.  
      The staple cartridge assembly  30  may also be configured with a longitudinal slot  64  that permits a knife shaft  66  having a distally positioned severing edge  68  to travel through the cartridge assembly  30 . In operation, when the instrument  10  is fired, the knife shaft  66  and its severing edge  68  are moved along a longitudinal axis of the cartridge assembly  30  through the slot  64  by the action of a firing rod  70  cooperatively associated with the knife shaft  66 . The cooperative interaction of the firing rod  70  with the knife shaft  66  may be achieved through use of an adapter  72  mounted on the distal end of the firing rod  70 . The adapter  72  may be structured for connection to a drive block  74  that is connected to the knife shaft  66  with a locking member  76 . The drive block  74  may be secured to the locking member  76  by use of a retaining clip  78 , as shown in  FIG. 2 . It can be seen that urging the severing edge  68  of the knife shaft  66  through the cartridge assembly  30  with the firing rod  70  functions to sever tissue clamped between the anvil assembly  28  and the cartridge assembly  30 . In addition, a sled  82  may be positioned adjacent to a distal end of the knife shaft  66  to promote movement of the knife shaft  66  through the slot  64  of the cartridge assembly  30  and any tissue clamped between the cartridge assembly  30  and the anvil assembly  28 . A mounting plate  84  may also be attached to a lower portion of the knife shaft  66  to promote stability and movement of the knife shaft  66  as it travels through the lower channel  52 .  
      In various embodiments, the anvil assembly  28  may include at least two component parts: an upper plate  28 A structured for attachment (such as by frictional fit) to a lower plate  28 B. The lower plate  28 B of the anvil assembly  28  may include a plurality of staple receiving depressions (such as illustratively representative depressions  86 ,  88 ,  90  shown in  FIG. 4 , for example) formed therein which are structured for corresponding alignment with the staple holes  58 ,  60 ,  62 . The staple receiving depressions  86 ,  88 ,  90  receive staples from the staple cartridge  56  that are driven through severed tissue by the instrument  10 . A clip spring  92  may be positioned between a proximal portion of the lower plate  28 B of the anvil assembly  28  and a distal portion of the knife shaft  66 . The clip spring  92  may be structured with a resilient bias that promotes positioning of the anvil assembly  28  in a normally open position (i.e., a pre-firing position) relative to the staple cartridge assembly  30 . Also, a pin  94  may be received in a hole  96  formed in a distal portion of the knife shaft  66  that can be structured for operative association with a slot  98  formed along a longitudinal axis of the anvil assembly  28 . In operation of the instrument  10 , the anvil assembly  28  can be moved toward the cartridge assembly  30 , such as to clamp or position tissue therein, by action of the pin  94  as it initiates travel through the slot  98 .  
      Examples of typical surgical severing/stapling instruments that are functionally and structurally analogous to, and that may be provided in association with, embodiments of the present invention are disclosed in a U.S. patent to Yates et al. entitled, “Electrosurgical Device and Method” (U.S. Pat. No. 5,833,690, issued on Nov. 10, 1998), the entirety of which is incorporated herein by reference.  
      In various embodiments, an energy transmission system may be provided in association with the surgical instrument  10  to promote closure and healing of tissue incisions created by the severing/stapling action of the instrument  10 . The handle portion  20  may include an electrical power source  112  powered by a conventional battery or other suitable source of energy. The electrical power source  112  may be configured to generate and supply radio frequency (RF) energy, for example, that can be delivered by an electrical connection (such as wires  114 ,  116 ) to a first set of electrical contacts  118  positioned at the distal end of the shaft  24 . It can be appreciated by those skilled in the art that characteristics of the RF energy such as frequency, current, voltage and other characteristics, may be selected to promote safe and effective application of the RF energy to severed tissue.  
      The disposable severing/stapling unit  26  may include a second set of electrical contacts  122  structured and positioned on the proximal end of the disposable unit  26  to complete an electrical circuit with the first set of contacts  118  when the disposable unit  26  is removably connected to the shaft  24  for use during operation of the instrument  10 . The second set of contacts  122  may be electrically connected (such as by wires  124 ,  126 ) to a first set of electrodes  132 ,  134  positioned generally adjacent to rows of the multiple staple receiving depressions  86 ,  88 ,  90  formed in the anvil assembly  28 . The second set of contacts  122  may also be electrically connected to at least a second set of electrodes  136 ,  138  positioned generally adjacent to rows of the multiple staple holes  58 ,  60 ,  62  formed in the staple cartridge  56  of the cartridge assembly  30 . The electrodes  132 ,  134 ,  136 ,  138  may be comprised of any electrically conductive material such as copper, aluminum, silver, or other compositions of matter suitable for transferring electrical energy from the electrodes  132 ,  134 ,  136 ,  138  to severed tissue. It can be appreciated that conventional insulating structures and techniques may be employed to promote electrical isolation of the conductive components described herein for safe and effective transmission of electrical energy to the severed tissue.  
      Those skilled in the art will appreciate that either set of electrodes  132 ,  134 ,  136 ,  138 , or individual electrodes  132 ,  134 ,  136 ,  138  within each of the sets, may be charged negatively or positively as desired to complete an electrical circuit capable of delivering electrical energy to severed tissue. For example, the first set of electrodes  132 ,  134  in the anvil assembly  28  may be charged positively; and the second set of electrodes  136 ,  138  in the staple cartridge assembly  30  may be charged negatively. In certain embodiments, the electrodes  132 ,  134 ,  136 ,  138 , which are shown as single, continuous components in the figures for convenience of disclosure, may be separated into two or more separate components and appropriately electrically charged and electrically connected for transmission of electrical energy. In another example, one or more of the electrodes  132 ,  134 ,  136 ,  138  may be divided into two separate components: one component of the electrodes  132 ,  134 ,  136 ,  138  may be positively charged and another component of the electrodes  132 ,  134 ,  136 ,  138  may be negatively charged to create a current path in an electrical circuit for transmission of electrical energy between the two components. In certain embodiments, electrodes or electrode components may be positioned in specific predetermined locations on the anvil assembly  28  and/or the cartridge assembly  30  to facilitate focusing electrical energy on only certain portions of severed tissue.  
      In various embodiments, the disposable severing/stapling unit  26  may be provided with one or both of the electrodes  132 ,  134  positioned on the anvil assembly  28 , but with no corresponding electrodes positioned on the cartridge assembly  30 . In such embodiments, the electrodes  132 ,  134  on the anvil assembly  28  may be electrically connected to the electrical power source  112  to receive transmitted electrical current; and, at least a portion of the cartridge assembly  30  (e.g., a portion or portions of the staple cartridge  56 ) may be electrically grounded through a connection with the ground of the electrical power source  112 , for example, or through another suitable ground connection. Thus, one or both of the electrodes  132 ,  134  may be positively charged, and at least a portion of the cartridge assembly  30  may be electrically grounded. It can be seen that these configurations create a circuit that facilitates the flow of electrical current from the electrodes  132 ,  134 , through portions of severed/stapled tissue clamped between the anvil assembly  28  and the cartridge assembly  30 , to the grounded cartridge assembly  30 .  
      In various embodiments, the disposable severing/stapling unit  26  may be provided with one or both of the electrodes  136 ,  138  positioned on the cartridge assembly  30 , but with no corresponding electrodes positioned on the anvil assembly  30 . In such embodiments, the electrodes  136 ,  138  on the cartridge assembly  30  may be electrically connected to the electrical power source  112  to receive transmitted electrical current; and, at least a portion of the anvil assembly  28  may be electrically grounded through a connection with the ground of the electrical power source  112 , for example, or through another suitable ground connection. Thus, one or both of the electrodes  136 ,  138  may be positively charged, and at least a portion of the anvil assembly  28  may be electrically grounded. It can be seen that these configurations create a circuit that facilitates the flow of electrical current from the electrodes  136 ,  138 , through portions of severed/stapled tissue clamped between the anvil assembly  28  and the cartridge assembly  30 , to the grounded anvil assembly  28 .  
      It can be appreciated that electrical energy (e.g., RF electrical energy) may be employed in connection with operation of the surgical instrument  10  to cauterize or otherwise promote closure or sealing of severed tissue. In certain embodiments, the electrical power source  112  may be activated by a button or trigger  142  to manually cause current to flow through the energy transmission system to the electrodes  132 ,  134 ,  136 ,  138 . The electrical power source  112  may also be configured to activate and generate electrical energy automatically in association with firing the instrument  10 . For example, in association with firing the instrument  10  to sever/staple tissue, the electrical power source  112  may be automatically activated to transmit RF energy through one or more of the electrodes  132 ,  134 ,  136 ,  138  of the energy transmission system to cauterize or otherwise promote closure and sealing of tissue severed and stapled by action of the instrument  10 .  
      It will be appreciated that the terms “proximal” and “distal” may be used herein as convenient terms of relative orientation, such as with reference to a clinician gripping a handle of an instrument. For example, the disposable unit  26  may be considered “distal” with respect to the “proximal” handle portion  20  (see, e.g.,  FIG. 1 ). It will be further appreciated that, for convenience and clarity of disclosure, spatially paired terms of relative orientation such as “top” and “bottom”; “upper” and “lower”; or “downward” and “upward” may be used herein with respect to the drawings. Those skilled in the art will appreciate, however, that surgical instruments may be used in many orientations and positions, and such terms are not intended to be limiting and absolute.  
      Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is done so only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in the present disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.  
      The examples presented herein are intended to illustrate potential and specific implementations of the present invention for those skilled in the art. No particular aspect or aspects of the examples included herein are necessarily intended to limit the scope of the present invention.  
      It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for purposes of clarity, other elements. Those of ordinary skill in the art will recognize, however, that these and other elements may be desirable in a typical computer system or database system. However, because such elements are well known in the art and because they do not facilitate a better understanding of the present invention, a discussion of such elements may not be provided herein.  
      Any element expressed herein as a means for performing a specified function is intended to encompass any way of performing that function including, for example, a combination of elements that perform that function. Furthermore the invention, as defined by such means-plus-function claims, resides in the fact that the functionalities provided by the various recited means are combined and brought together in a manner as defined by the appended claims. Therefore, any means that can provide such functionalities may be considered equivalents to the means shown herein.  
      In various embodiments of the present invention disclosed herein, a single component may be replaced by multiple components, and multiple components may be replaced by a single component, to perform a given function or functions. Except where such substitution would not be operative to practice embodiments of the present invention, such substitution is within the scope of the present invention.  
      While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications may readily appear to those skilled in the art. The present invention has been discussed in terms of endoscopic procedures and apparatus. However, use herein of terms such as “endoscopic” should not be construed to limit the present invention to a surgical stapling and severing instrument for use only in conjunction with an endoscopic tube (i.e., trocar). On the contrary, it is believed that surgical instruments structured in accordance with the present invention may find use in many surgical procedures, including but not limited to laparoscopic procedures and open procedures. Moreover, the unique and novel aspects of the embodiments of the present invention may find utility when used in connection with other forms of stapling apparatuses without departing from the spirit and scope of the present invention.