Patent Publication Number: US-2023157688-A1

Title: Anvil assembly with cutting plate

Description:
FIELD 
     The present technology is generally related to surgical stapling devices and, more particularly, to surgical stapling devices that have a cutting knife and an anvil cutting plate to receive the cutting knife. 
     BACKGROUND 
     Surgical stapling devices are commonly used during a variety of surgical procedures to expedite dissection and suturing of tissue and minimize trauma to a patient. Typically, the stapling devices include an end effector that includes a cartridge assembly and an anvil assembly. The cartridge assembly includes a knife assembly for cutting tissue and the anvil assembly supports a cutting plate which is engaged by the knife assembly to provide a more effective cutting process. The knife assembly includes a knife blade that has a sharpened cutting edge which is driven through tissue and into the cutting plate to transect or resect the tissue. 
     Surgical stapling devices are available in a variety of types for performing a variety of different surgical procedures. One type of stapling device includes a U-shaped end effector that has a first transverse portion, a second transverse portion, and a longitudinal portion interconnecting the first transverse portion and the second transverse portion. Each of the first and second end portions has a first end coupled to the longitudinal portion and a second free end. The anvil assembly is supported on the first transverse portion and the cartridge assembly is supported adjacent the second transverse portion and is movable towards the first transverse portion to move the anvil and cartridge assemblies into juxtaposed alignment. 
     During a surgical procedure, when the knife assembly is advanced into engagement the cutting plate of the anvil assembly, the free end of the first transverse portion supporting the anvil assembly tends to bend distally when the force of the knife assembly is applied to the anvil assembly. This causes the anvil assembly to bend distally such that the knife assembly applies a greater force on tissue nearer to the first end of the anvil assembly than to tissue nearer to the free end of the anvil assembly. This may result in ineffective cutting of tissue near the free end of the anvil assembly. 
     A continuing need exists in the art for an end effector that can compensate for distal deflection of the free end of the anvil assembly during cutting of tissue. 
     SUMMARY 
     Aspects of this disclosure are directed to an end effector for a transverse type surgical stapling device that includes an end effector including a U-shaped frame, an anvil assembly, and a cartridge assembly. The U-shaped frame includes a first transverse portion, a second transverse portion, and a longitudinal portion that interconnects the first and second transverse portions. The first transverse portion includes a first end that is coupled to the longitudinal portion and a second free end. The anvil assembly is supported on the first transverse portion and includes a cutting plate and an anvil plate that is secured to the first transverse portion such that the cutting plate is sandwiched between the first transverse portion and the anvil plate. The cutting plate has a thickness that changes between its first and second ends to compensate for deformation of the first transverse portion of the frame during firing of the stapling device. 
     One aspect of the disclosure is directed to an end effector that includes a frame and an anvil assembly. The frame has a U-shaped configuration and includes a first transverse portion, a second transverse portion, and a longitudinal portion that interconnects the first transverse portion and the second transverse portion. The first transverse portion is spaced from the second transverse portion to define a gap. The first transverse portion of the frame has a first end coupled to the longitudinal portion of the frame and a second free end. The anvil assembly is supported on the first transverse portion of the frame and includes a cutting plate and an anvil plate. The cutting plate has a first end positioned adjacent the first end of the first transverse portion of the frame and a second end positioned adjacent the second free end of the first transverse portion of the frame. The anvil plate is secured to the first transverse portion of the frame proximally of the cutting plate such that the cutting plate is sandwiched between the anvil plate and the first transverse portion. The thickness of the cutting plate increases from the first end of the cutting plate to the second end of the cutting plate. 
     In aspects of the disclosure, the cutting plate is formed from a material selected from a polyether ether ketone, a polyoxymethylene, a polyphenylsulfone, a metal, polypropylene, polyethylene, a thermoplastic elastomer, polyurethane, thermoplastic polyurethanes or combinations thereof. 
     In some aspects of the disclosure, the cutting plate includes a proximally extending central rib and the anvil plate defines a knife slot that is aligned with the central rib. 
     In certain aspects of the disclosure, the cutting plate includes a body having a proximally facing surface, and the central rib extends proximally from the proximally facing surface. 
     In aspects of the disclosure, the proximally facing surface of the cutting plate includes first relief grooves that extend along opposite sides of the central rib of the cutting plate. 
     In some aspects of the disclosure, the cutting plate includes a distally facing surface that defines a second relief groove that is aligned with the central rib. 
     In certain aspects of the disclosure, the second relief groove has a width that extends across the central rib and the first relief grooves. 
     In aspects of the disclosure, the cutting plate has a side wall that extends about the body and extends proximally of the body to define a proximal recess and distally of the body to define a distal recess. 
     In some aspects of the disclosure, the first transverse portion of the frame is received within the distal recess and the anvil plate is received within the proximal recess. 
     In certain aspects of the disclosure, the anvil assembly is curved. 
     Another aspect of this discourse is directed to a surgical stapling device that includes a handle assembly, a frame, a clamp slide assembly, a cartridge assembly, and an anvil assembly. The frame defines a longitudinal axis and includes a distal frame portion having a U-shaped configuration. The distal frame portion includes a first transverse portion, a second transverse portion, and a longitudinal portion interconnecting the first transverse portion and the second transverse portion. The first transverse portion is spaced from the second transverse portion to define a gap. The first transverse portion of the distal frame portion has a first end coupled to the longitudinal portion of the distal frame portion and a second free end. The clamp slide assembly has a distal portion supported within the gap that includes a cartridge receiving portion. The cartridge assembly is supported on the cartridge receiving portion of the clamp slide assembly. The anvil assembly is supported on the first transverse portion of the distal frame portion and a cutting plate and an anvil plate. The cutting plate has a first end positioned adjacent the first end of the first transverse portion of the distal frame portion and a second end positioned adjacent the second free end of the first transverse portion of the distal frame portion. The anvil plate is secured to the first transverse portion of the distal frame portion proximally of the cutting plate such that the cutting plate is sandwiched between the anvil plate and the first transverse portion of the distal frame portion. The thickness of the cutting plate increases from the first end of the cutting plate to the second end of the cutting plate. 
     Another aspect of this disclosure is directed to an anvil assembly including a cutting plate and an anvil plate. The cutting plate has a first end and a second end. The anvil plate is positioned in juxtaposed alignment with the cutting plate. The thickness of the cutting plate increases from the first end of the cutting plate to the second end of the cutting plate. 
     Other features of the disclosure will be appreciated from the following description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various aspects of the disclosure are described herein below with reference to the drawings, wherein: 
         FIG.  1    is a side perspective view of a surgical stapling device including aspects of the disclosure; 
         FIG.  2    is a side perspective cutaway view of a distal portion of end effector of the surgical stapling device shown in  FIG.  1    with parts separated; 
         FIG.  3    is a side perspective view of a cutting plate of an anvil assembly of the surgical stapling device shown in  FIG.  1   ; 
         FIG.  4    is a cross-sectional view taken along section line  4 - 4  of  FIG.  3   ; 
         FIG.  5    is a cross-sectional view taken along section line  5 - 5  of  FIG.  3   ; 
         FIG.  6    is a cross-sectional view taken along section line  6 - 6  of  FIG.  1   ; 
         FIG.  7    is an enlarged view of the indicated area of detail shown in  FIG.  6   ; 
         FIG.  8    is a schematical cross-sectional view taken along section line  8 - 8  of  FIG.  1   ; 
         FIG.  9    is a side perspective view of the end effector of the surgical stapling device shown in  FIG.  1    in a clamped and fired position; 
         FIG.  10    is a cross-sectional view taken along section line  10 - 10  of  FIG.  9   ; 
         FIG.  11    is an enlarged view of the indicated area of detail shown in  FIG.  10   ; and 
         FIG.  12    is a side cutaway view of the end effector of the shown in  FIG.  9    in the clamped and fired position with a knife assembly of a cartridge assembly and a thrust bar shown in phantom. 
     
    
    
     DETAILED DESCRIPTION 
     The disclosed surgical stapling devices will now be described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. However, it is to be understood that the aspects of the disclosure are merely exemplary and may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the disclosure in virtually any appropriately detailed structure. In addition, directional terms such as front, rear, upper, lower, top, bottom, distal, proximal, and similar terms are used to assist in understanding the description and are not intended to limit the disclosure. 
     In this description, the term “proximal” is used generally to refer to that portion of the device that is closer to a clinician during use of the device in its customary manner, while the term “distal” is used generally to refer to that portion of the device that is farther from the clinician during use of the device in its customary manner. In addition, the term “clinician” is used generally to refer to medical personnel including doctors, nurses, and support personnel. “About” or “approximately” or “substantially” as used herein may be inclusive of the stated value and means within an acceptable range of variation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (e.g., the limitations of the measurement system). For example, “about” may mean within one or more standard variations, or within ±10% of the stated value. 
       FIG.  1    illustrates the disclosed surgical stapling device shown generally as stapling device  10 . The stapling device  10  includes a handle assembly  12 , an elongate body  14  that extends distally from the handle assembly  12 , and an end effector  16  that is supported on a distal portion of the elongate body  14 . The elongate body  14  defines a longitudinal axis “X”. The handle assembly  12  includes a housing  18  that defines a stationary handle  20  and supports a movable trigger  22 . In aspects of the disclosure, the movable trigger  22  is supported by the housing  18  to pivot towards the stationary handle  20  between non-actuated and actuated positions to operate the end effector  16 . The handle assembly  12  also supports buttons  26  (only one is shown) that are positioned on each side of the housing  18  and are movable along the housing  18  to advance and retract an alignment pin pusher  27 . The alignment pin pusher  27  is positioned and configured to engage an alignment pin (not shown) within the end effector to move the alignment pin between retracted position and advanced positions. The handle assembly  12  also includes a release button  28  that can be depressed to move the end effector  16  from a clamped position to an unclamped position. For a more detailed description of a suitable handle assembly  12 , see, e.g., U.S. Pat. No. 6,817,508 (“the &#39;508 Patent”). 
     The stapling device  10  includes a frame  32  that extends from the handle assembly  12  to the end effector  16 . The frame  32  includes a distal frame portion  34  that has a U-shaped configuration that forms a portion of the end effector  16 . The distal frame portion  34  ( FIG.  3   ) has a first transverse portion  36 , a second transverse portion  38 , and a longitudinal portion  39  that interconnects the first transverse portion  36  and the second transverse portion  38 . The first and second transverse portions  36  and  38  are spaced from each other to define a gap  40  that extends between the first and second transverse portions  36  and  38 . In some aspects of the disclosure, the first and second transverse portion  36  and  38  are curved along axes transverse to the longitudinal axis “X” of the elongate body  14  of the stapling device  10 . Alternately, the first and second transverse portions may be linear or comprised of a plurality of linear portions that are positioned at angles in relation to each other. Each of the first and second transverse portions  36  and  38  has a first end coupled to (e.g., formed with) the longitudinal portion  39  of the distal frame portion  34  and a second free end  36   a  and  38   a.  The first transverse portion  36  has a substantially flat or planar proximal surface  41  ( FIG.  2   ). 
     The end effector  16  includes an anvil assembly  42  and a cartridge assembly  44 . The cartridge assembly  44  is removably supported on a clamp slide assembly  46  of the stapling device  10  and includes a body  47  that supports a plurality of staples  110  ( FIG.  6   ). The clamp slide assembly  46  includes a distal portion  46   a  that is configured to releasably support the cartridge assembly  44 . The distal portion  46   a  is positioned in the gap  40  and is movable between retracted and advanced positions to move the cartridge assembly  44  in relation to the anvil assembly  42  through the gap  40  between an unclamped position ( FIG.  1   ) located adjacent to the second transverse portion  38  of the distal frame portion  34  and a clamped position ( FIG.  9   ) located adjacent to the first transverse portion  36  of the distal frame portion  34 . For a detailed description of exemplary aspects of the operation and construction of a clamp slide assembly, see the &#39;508 Patent. 
       FIGS.  2 - 8    illustrate the anvil assembly  42  of the end effector  16  of the stapling device  10 . The anvil assembly  42  is supported on the first transverse portion  36  of the distal frame portion  34  and includes a cutting plate  52  and an anvil plate  54 . The cutting plate  52  and the anvil plate  54  have configurations that correspond to the configuration of the first transverse portion  36  of the distal frame portion  34 . The cutting plate  52  includes a body portion  60  and a side wall  62  that extends about a periphery of the body portion  60  to define proximal and distal recesses  64  and  66  ( FIG.  5   ) on the proximal and distal sides of the cutting plate  52 . The side wall  62  defines opposed cutouts  62   a.  The body portion  60  includes a first end  60   a  positioned adjacent to the longitudinal portion  39  of the distal frame portion  34  and a second end  60   b  that is positioned adjacent to the free end  36   a  ( FIG.  2   ) of the first transverse portion  36  of the distal frame portion  34 . The distal recess  66  receives the first transverse portion  36  of the distal frame portion  34 . When the cutting plate  52  is supported on the first transverse portion  36  of the distal frame portion  34 , the side wall  62  of the cutting plate  52  is received within a recess  68  ( FIG.  2   ) that is formed about the periphery of the first transverse portion  36  of the distal frame portion  34  to securely position the cutting plate  52  on the distal frame portion  34  of the stapling device  10 . 
     The body portion  60  of the cutting plate  52  includes a central rib  70  that extends along most of the length of the cutting plate  52  within the proximal recess  64 . A first relief groove  72  ( FIG.  5   ) is formed into a proximal surface of the body portion  60  of the cutting plate  52  on each side of the central rib  70 . In some aspects of the disclosure, a second relief groove  74  ( FIG.  5   ) is formed in a distal surface of the body portion  60  of the cutting plate  52  beneath the central rib  70 . The second relief groove  74  can have a width that extends across the central rib  70  and the first relief grooves  72 . The body portion  60  of the cutting plate  52  also defines an alignment pin opening  76  that is positioned to receive the alignment pin (not shown) of the cartridge assembly  44  when the alignment pin is moved from its retracted to its advanced position. The &#39;508 Patent describes the operation and construction of an exemplary alignment pin. 
     In aspects of the disclosure, the body portion  60  of the cutting plate  52  has a thickness that increases from first end  60   a  of the body portion  60  towards the second end  60   b  of the cutting plate  60 . The change in thickness may be uniform along the length of the body portion  60  of the cutting plate  52  or, alternately may be non-uniform and selected to achieve uniform cutting of tissue as described below. In aspects of the disclosure, the first end  60   a  of the cutting plate  52  can have a thickness of from about 0.020 inches to about 0.040 inches and the second end  60   b  of the body portion  60  can have a thickness of from about 0.065 inches to about 0.090 inches. In certain aspects of the disclosure, the first end  60   a  of the body portion  60  of the cutting plate  52  has a thickness of about 0.029 inches and the second  60   b  of the body portion  60  has a thickness of about 0.077 inches. 
     In aspects of the disclosure, the cutting plate  52  is formed from a plastic material such as a polyether ether ketone (PEEK) material, a polyoxymethylene (POM) material, or a polyphenylsulfone material (PPSU)polypropylene, polyethylene, a thermoplastic elastomer, polyurethane, thermoplastic polyurethanes or combinations thereof. In other aspects of the disclosure, the cutting plate  76  is formed by injection molding although other methods of manufacture are envisioned. The cutting plate  76  should be formed of a material that will deform locally and structurally upon engagement with the knife  102 . Local deformation of the cutting plate  76  ensures that no gap exists between the knife  102  and the surface of the cutting plate  76  to facilitate a clean cut through tissue. The structural deformation limits the firing force required to fire the stapling device  10 . 
       FIG.  4    illustrates the anvil plate  54  of the anvil assembly  42  which includes a body  54   a  that defines a knife slot  80  and an alignment pin bore  82  that receives the alignment pin (not shown). The anvil plate  54  includes a first end  55   a  and a second end  55   b  and is positioned on top of the cutting plate  52  within the proximal recess  64  to sandwich the cutting plate  52  between the anvil plate  54  and the first transverse portion  36  of the distal frame portion  34 . In aspects of the disclosure, the anvil plate  54  includes flanges  84  ( FIG.  2   ) and the first transverse portion  36  of the distal frame portion  34  defines cutouts  86  ( FIG.  2   ). The flanges  84  extend through the cutouts  62   a  of the cutting plate  52  and are secured within the cutouts  86  of the first transverse portion  36  of the distal frame portion  34  to secure the anvil assembly  42  to the first transverse portion  36  of the distal frame portion  34 . In certain aspects of the disclosure, the flanges  84  define openings  88  that receives a rivet or pin  90  to secure the anvil plate  54  and the cutting plate  52  to the first transverse portion  36  of the distal frame portion  34 . The anvil plate  54  includes a proximal staple forming surface  92  which defines staple forming pockets  94  on each side of the knife slot  80 . 
       FIGS.  6  and  7    illustrate the end effector  16  of the stapling device  10  with the anvil assembly  42  secured to the distal transverse portion  36  of the of the distal frame portion  34  and the cartridge assembly  44  supported within the clamp slide assembly  46 . In this position, the cutting plate  52  is sandwiched between the distal transverse portion  36  of the central rib  72  of the cutting plate  52  is aligned and projects partially through the knife slot  80  of the anvil plate  54 . It is envisioned that the central rib  70  of the cutting plate  52  can extend entirely through the knife slot  80  of the anvil plate  54  or, in the alternative, can be recessed slightly beneath the knife slot  80  of the anvil plate  54 . 
       FIG.  6    illustrates the cartridge assembly  44  supported within the clamp slide assembly  46  of the stapling device  10 . As illustrated, the cartridge assembly  44  includes a knife assembly  100  that is supported within the body  47  of the cartridge assembly  44 . The cartridge body  47  defines a knife slot  102 . The knife assembly  100  includes a knife carrier  104  and a knife  106 . The knife  106  includes a cutting edge  106   a  that is aligned with the central rib  70  of the cutting plate  52 . The cartridge assembly  44  also includes a staple pusher  108  that is moved from a retracted position to an advanced position within the cartridge body  44  to eject staples  110  from the cartridge body  47  into the anvil assembly  44 . When the staples  110  are driven into the anvil assembly  42 , the force applied to the anvil assembly  42  causes the free end  36   a  of the first transverse portion of the distal frame portion  34  to bend distally in relation to the first end of the first transverse portion  36 . This causes the second end  55   b  of the anvil plate  55  to move distally in relation to the first end of the anvil plate  54 . The clamp slide assembly  46  is movable from a retracted position to an advanced position to move the cartridge assembly  44  towards the anvil assembly  42  from an open position to a clamped position. 
       FIG.  8    illustrates a schematic side view of the distal frame portion  34  of the stapling device  10  ( FIG.  1   ) with the knife assembly  100  shown in phantom in a retracted position. As illustrated, the planar proximal surface  41  of the first transverse portion  36  of the distal frame portion  34  defines a plane “Y” that defines an angle Ω with the longitudinal axis “X” of the elongate body  14 . The angle Ω may be substantially 90 degrees. The distal surface of the cutting plate  52  rests upon the proximal surface  41  of the first transverse portion  36 . Since the thickness of the cutting plate  52  increases from the first end  60   a  of the body portion  60  of the cutting plate  52  to the second end  60   b  of the cutting plate  52 , the proximal surface of the body  60  of the cutting plate  52  defines an angle β with the plane “Y”. In aspects of the disclosure, β is from about 1 degree to about 3 degrees. In some aspects of the disclosure, β is about 1.70 degrees. Since the anvil plate  54  is supported atop the proximal surface of the cutting plate  52 , the body  54   a  of the anvil plate  54  also defines angle β with the plane “Y”. As such, the second end  55   b  of the anvil plate  54  is angled towards the cartridge assembly  44  and is positioned proximally of the first end  55   a  of the anvil plate  54 . 
       FIGS.  9 - 12    illustrate the end effector  16  of the stapling device  10  after the stapling device  10  ( FIG.  1   ) is fired. Prior to firing of the stapling device  10 , the clamp slide assembly  46  is moved from a retracted position to an advanced position to move the cartridge assembly  44  in relation to the anvil assembly  42  from the open position ( FIG.  1   ) to the clamped position ( FIG.  9   ). The &#39;508 Patent discloses operation of an exemplary clamp slide assembly for moving a cartridge assembly of a stapling device towards an anvil assembly from the open position to a clamped position. 
     When the stapling device  10  ( FIG.  1   ) is fired, the staple pusher  108  ( FIG.  10   ) is advanced in the direction of arrows “A” in  FIG.  12    to drive the staples  110  ( FIG.  6   ) from the cartridge assembly  44  into the anvil assembly  52  and the knife assembly  100  ( FIG.  9   ) is advanced in the direction of arrows “A” in  FIG.  12    to advance the knife  106  through the knife slot  80  ( FIG.  11   ) in the anvil plate  54  into the central rib  70  of the cutting plate  52  of the anvil assembly  42 . Prior to firing of the stapling device  10 , the anvil plate  54  is positioned as shown in  FIG.  8    with the second end  55   b  of the anvil plate  54  angled distally towards (positioned closer to) the cartridge assembly  44 . When the stapling device  10  is fired and forces are applied to the anvil assembly  42  by the staples  110  as the staples  110  are formed on the anvil plate  54 , the free end  36   a  ( FIG.  12   ) of the first transverse portion  36  of the distal frame portion  34  is deformed distally in the direction of arrow “B” in  FIG.  12    to a position in which the first and second ends  55   a  and  55   b  of the anvil plate  54  are substantially aligned along an transverse axis to the longitudinal axis “X” of the elongate body  14  ( FIG.  1   ) of the stapling device  10 . This allows for the knife  106  to apply a cutting force that is evenly distributed along the central rib  70  of the cutting plate  52  to effect complete transection or resection of tissue (not shown) that is clamped between the anvil assembly  42  and the cartridge assembly  44 . 
     When the knife  106  is advanced from its retracted position to its advanced position in the direction indicated by arrows “A” in  FIG.  12   , the cutting edge  106   a  of the knife  106  of the knife assembly  100  engages the central rib  70  of the cutting plate  52  and applies a force in the distal direction to the central rib  70 . As described above, first and second relief grooves  72  and  74  are positioned on proximal and distal surfaces of the cutting plate  52  adjacent the central rib  70 . The relief grooves allow the central rib  70  to be deformed distally into the second relief groove  74  ( FIG.  11   ). This allows the knife  106  to move in relation to tissue (not shown) that is clamped between the anvil and cartridge assemblies  42  and  44  to ensure that the tissue (not shown) clamped between the anvil and cartridge assemblies  42  and  44  is cleanly and completely transected or resected. As noted above, the thickness of the cutting plate  52  varies from the first end  60   a  of the cutting plate  52  to the second end  60   b  of the cutting plate  52 . This change in thickness of the cutting plate  52  is provided to compensate for deformation of the free end  36   a  of the first transverse portion  36  in the direction of arrow “B” in  FIG.  12    as the stapling device  10  ( FIG.  1   ) is fired. More specifically, the change in the thickness of the cutting plate  52  allows central rib  70  of the cutting plate to move to a position that is substantially parallel to the cutting edge  106   a  of the knife  106  as the stapling device  10  ( FIG.  1   ) is fired to evenly distribute the cutting forces of the knife  106  along the central rib  70  of the cutting plate  52  as the first transverse portion  36  of the distal frame portion  34  deforms distally during firing of the stapling device  10  ( FIG.  1   ). 
     Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary aspects of the disclosure. It is envisioned that the elements and features illustrated or described in connection with one exemplary aspect of the disclosure may be combined with the elements and features of another without departing from the scope of the disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the above-described aspects of the disclosure. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.