Patent Publication Number: US-2021161526-A1

Title: Linear Stapling Device With A Gap Locking Member

Description:
FIELD 
     This disclosure is directed to a surgical stapling device and, more particularly, to a linear surgical stapling device having a tool assembly that defines a tissue gap and includes a locking member to maintain the tissue gap during firing of the stapling device. 
     BACKGROUND 
     Surgical stapling devices are commonly used during a variety of surgical procedures to staple and/or cut tissue. Stapling and cutting of tissue can be accomplished more quickly using surgical stapling devices than can be accomplished using traditional suturing techniques. In addition, endoscopic stapling devices can be used to perform less invasive surgical procedures than possible using traditional suturing techniques. As such, the use of surgical stapling devices to perform certain surgical procedures to reduce patient trauma and improve patient recovery times is desirable. 
     Typically, linear endoscopic surgical stapling devices include a tool assembly that includes a staple cartridge and an anvil assembly that are movable in relation to each other between open and clamped positions. The staple cartridge defines a plurality of staple pockets that receive staples and the anvil assembly defines a plurality of staple deforming pockets. When the tool assembly is in the clamped position, the staple deforming pockets of the anvil assembly are aligned with the staple pockets of the staple cartridge such that legs of the staples are received and deformed within the staple deforming pockets when the stapling device is fired. The staple cartridge and the anvil assembly must be properly aligned to effect proper staple formation. 
     Generally, the staple cartridge and the anvil assembly have proximal ends that are secured to each other by a pivot member such that the staple cartridge and the anvil assembly can be pivoted from the open position in which distal ends of the staple cartridge and the anvil assembly are spaced from each other to the clamped position in which the staple cartridge and the anvil assembly are in juxtaposed alignment. During firing of the staples from the staple cartridge, forces on the staple cartridge and the anvil assembly for firing the staples tend to deflect the staple cartridge and anvil assembly outwardly away from each other. In certain stapling devices, a knife bar is provided that includes upper and lower beams that engage the anvil assembly and staple cartridge to minimize deflection of the anvil and cartridge assemblies during firing. 
     SUMMARY 
     One aspect of this disclosure is directed to a tool assembly including an anvil, a cartridge assembly, a clamping member, and a locking member. The anvil and the cartridge assembly each have a proximal portion and a distal portion. The proximal portion of the cartridge assembly is pivotally coupled to the proximal portion of the anvil. The clamping member is movable in relation to the anvil and the cartridge assembly between retracted and advanced positions to move the tool assembly between an open position and a clamped position. The locking member is supported on one of the anvil or the cartridge assembly and is movable from an unlocked position to a locked position. In the locked position, the locking member is engaged with the distal portion of the other of the anvil or the cartridge assembly to maintain a tissue gap between the distal portion of the anvil and the cartridge assembly. 
     In embodiments, the clamping member is positioned to move the locking member from the unlocked position to the locked position as the clamping member moves in relation to the anvil and the cartridge assembly. 
     In some embodiments, the locking member is supported on the cartridge assembly and includes an elongate member having a proximal portion and a distal portion, wherein the distal portion of the elongate member has an engagement portion that is engaged with the distal portion of the anvil when the locking member is in the locked position. 
     In certain embodiments, a tissue dissector is supported on the distal portion of the anvil and the tissue dissector defines a bore that is positioned to receive the engagement portion of the elongate member when the locking member is in the locked position. 
     In embodiments, the tissue dissector is angled towards the cartridge assembly when the tool assembly is in the clamped position and the engagement portion includes an angled finger that is received in the bore of the tissue dissector. 
     In some embodiments, the proximal portion of the locking member is engaged by the clamping member when the clamping member moves from its retracted position towards its advanced position. 
     In certain embodiments, the cartridge assembly includes a staple cartridge and the tool assembly includes a pusher that extends through a bore in a distal portion of the staple cartridge, wherein the pusher has a proximal portion and a distal portion engaged with the locking member. 
     In embodiments, a spring is positioned within the bore of the staple cartridge to urge the locking member towards its unlocked position and the pusher is movable to move the locking member to its locked position against a bias of the spring. 
     In some embodiments, a tissue dissector is supported on the distal portion of the anvil and defines a bore that is aligned with the locking member when the tool assembly is in the clamped position, wherein the locking member is received within the bore when the locking member is in the locked position. 
     In certain embodiments, the proximal portion of the pusher engages the clamping member as the clamping member moves between its retracted position and its advanced position. 
     In embodiments, the locking member includes a tissue dissector that is supported on the distal portion of the anvil. 
     In some embodiments, the tissue dissector is pivotally supported on the distal portion of the anvil. 
     In certain embodiments, a pusher has a proximal portion and a distal portion aligned with the locking member, wherein the pusher is movable to move the locking member from its unlocked position to its locked position. 
     In embodiments, the proximal portion of the pusher is engaged by the clamping member when the clamping member moves from its retracted position to its advanced position. 
     In some embodiments, a spring is positioned between the tissue dissector and the anvil to urge the locking member to its locked position. 
     Another aspect of this disclosure is directed to a method of maintaining a tissue gap between a cartridge assembly and an anvil, wherein the method includes moving an anvil of a stapling device in relation to a cartridge assembly of the stapling device from an open position to a clamped position; and moving a locking member of the stapling device from an unlocked position to a locked position to connect a distal portion of the anvil to a distal portion of the cartridge. 
     In embodiments, moving the locking member of the stapling device from the unlocked position to the locked position includes advancing the locking member along the cartridge assembly into engagement with the anvil. 
     In some embodiments, moving the locking member of the stapling device from the unlocked position to the locked position includes pivoting the locking about a pivot member supported on the anvil into engagement with a projection supported on the cartridge assembly. 
     In certain embodiments, moving the anvil of the stapling device in relation to the cartridge assembly of the stapling device from the open position to the clamped position includes advancing a clamping member along the anvil and the cartridge assembly. 
     In embodiments, moving the locking member of the stapling device from the unlocked position to the locked position includes engaging the locking member with the clamping member to move the locking member from its unlocked position to its locked position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments of the disclosed linear surgical stapling device including a tool assembly locking member are described herein below with reference to the drawings, wherein: 
         FIG. 1  is a side perspective view of an exemplary embodiment of the disclosed stapling device including a tool assembly having a dissector tip with the tool assembly in an open position; 
         FIG. 2  is an enlarged view of the tool assembly of the stapling device shown in  FIG. 1  in the open position; 
         FIG. 3  is a bottom perspective view of the tool assembly shown in  FIG. 2  with the tool assembly in the open position; 
         FIG. 4  is an exploded perspective view of the tool assembly shown in  FIG. 3 ; 
         FIG. 5  is a cross-sectional view along the longitudinal axis of the tool assembly shown in  FIG. 3  with the tool assembly in the clamped position and the locking member in the unlocked position; 
         FIG. 6  is a cross-sectional view along the longitudinal axis of the tool assembly shown in  FIG. 3  with the tool assembly in the clamped position and the locking member in the locked position; 
         FIG. 7  is a cross-sectional view taken along the longitudinal axis of another embodiment of the tool assembly in accordance with this disclosure with the tool assembly in the clamped position and the locking member in the unlocked position; 
         FIG. 8  is an enlarged view of the indicated area of detail shown in  FIG. 7 ; 
         FIG. 9  is a cross-sectional view of the tool assembly shown in  FIG. 7  with the tool assembly in the clamped position and the locking member in the locked position; 
         FIG. 10  is an enlarged view of the indicated area of detail shown in  FIG. 9 ; 
         FIG. 11  is a side perspective view of a distal portion of another embodiment of a tool assembly in accordance with the disclosure with the tool assembly in the clamped position and the locking member in the unlocked position; 
         FIG. 12  is a side perspective view of the distal portion of the tool assembly shown in  FIG. 11  with the tool assembly in the clamped position, the locking member in the unlocked position, and the dissecting tip shown in phantom; 
         FIG. 13  is a cross-sectional view taken along section lines  13 - 13  of  FIG. 11 ; 
         FIG. 14  is an enlarged view of the indicated area of detail shown in  FIG. 13  with the locking member in the unlocked position; and 
         FIG. 15  is an enlarged view of the indicated area of detail shown in  FIG. 13  with the locking member moved to the locked position. 
     
    
    
     DETAILED DESCRIPTION 
     The disclosed surgical stapling device 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 disclosed embodiments are merely exemplary of the disclosure 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 this description, the term “proximal” is used generally to refer to that portion of the device that is closer to a clinician, while the term “distal” is used generally to refer to that portion of the device that is farther from the clinician. In addition, the term “clinician” is used generally to refer to medical personnel including doctors, nurses, and support personnel. 
     In  FIG. 1 , the surgical stapling device is illustrated generally as stapling device  10  and includes a handle assembly  12 , an elongate body  14 , and a staple reload  16 . The elongate body  14  defines a longitudinal axis “X” and includes a proximal portion that is coupled to the handle assembly  12  and a distal portion that supports the staple reload  16 . The staple reload  16  includes a proximal body portion  18  and a tool assembly  20 . The proximal body portion  18  is releasably coupled to the distal portion of the elongate body  14 . Alternately, the staple reload  16  and the elongate body  14  can be integrally formed such that the tool assembly  20  is fixedly attached to the elongate body  14 . 
     The handle assembly  12  includes a housing  24  that defines a stationary handgrip  26  and supports a movable trigger  28  and a rotation knob  30 . The rotation knob  30  is coupled to a distal portion of the housing  24  for rotation and supports the elongate body  14  such that rotation of the rotation knob  30  causes rotation of the elongate body  14  about the longitudinal axis “X”. The movable trigger  28  is supported by the housing  24  and can be pivoted in relation to the stationary handgrip  26  to actuate the tool assembly  20 . In embodiments, the rotation knob also supports an articulation knob  34  that can pivot or rotate about an axis perpendicular to the longitudinal axis “X” to articulate the tool assembly  20  from a position aligned with the longitudinal axis “X” to a position misaligned with the longitudinal axis “X”. Although illustrated as being a manually operated handle assembly, it is envisioned that the handle assembly may be electrically or pneumatically powered, and may be adapted for use or coupled to a robotic surgical system. 
       FIGS. 2-4  illustrate the tool assembly  20  which includes an anvil  34  and a cartridge assembly  36 . Each of the anvil  34  and the cartridge assembly  36  includes a distal portion and a proximal portion. The proximal portion of the anvil  34  is coupled to the proximal portion of the cartridge assembly  36  by a pivot member  38  such that the tool assembly  20  can pivot between an open position ( FIG. 2 ) and a clamped position ( FIG. 3 ). 
     In embodiments, the cartridge assembly  36  includes a channel  45  that defines a longitudinal slot  45   a  ( FIG. 3 ) and a staple cartridge  46  having a tissue contact surface  47 . The staple cartridge  46  defines a plurality of staple pockets  48  and is received within the channel  45 . In some embodiments, the staple cartridge  46  is adapted to be released from the channel  45  after firing of the stapling device  10  and replaced with a new or loaded staple cartridge  46 . Each of the staple pockets  48  is configured and dimensioned to receive a staple (not shown). In embodiments, the staple cartridge  46  has a tissue guide portion  46   a  that is angled away from the anvil  34  in the distal direction. 
     The anvil  34  defines a tissue engaging surface  34   a  ( FIG. 3 ) and includes a distal end portion that is angled from the tissue engaging surface  34   a  of the anvil  34  towards the cartridge assembly  36  at an acute angle. The angled distal end portion of the anvil  34  forms a dissecting tip  50  that defines an opening  52 . In embodiments, the dissecting tip  50  is spaced from the tissue guide portion  46   a  of the staple cartridge  46  when the tool assembly  20  is in the clamped position and extends along an axis that is substantially parallel to an axis defined by the tissue guide portion  46   a . Alternately, the dissecting tip  50  may have other configurations. 
     The tool assembly  20  also includes a drive assembly  60  ( FIG. 4 ). In embodiments, the drive assembly  60  of the tool assembly  20  includes a firing member  62  and clamping member  64 . The firing member  62  includes spaced cam bars  66  that define an elongate slot  68 . The cam bars  66  are coupled at their distal ends by an actuation sled  70 . As known in the art, the cam bars  66  can be moved from a retracted position to an advanced position to advance the actuation sled  70  through the tool assembly  20  to eject staples (not shown) from the staple cartridge  46 . The clamping member  64  may be coupled to a drive beam  71  that is received within the elongate slot  68  defined by the spaced cam bars  66 . 
     In embodiments, the clamping member  64  is pressed or frictionally retained between the cam bars  66  and includes an upper beam  74 , a lower beam  76 , and a vertical strut  78  that extends between the upper and lower beams  74 ,  76 . The upper beam  74  is positioned within a cutout  80  defined in the anvil  34  and is positioned to engage cam surfaces  82  on the anvil  34  such that distal movement of the clamping member  64  moves the anvil  34  about the pivot member  38  towards the cartridge assembly  36  from the open position ( FIG. 2 ) to the clamped position ( FIG. 5 ). The lower beam  76  is positioned to engage and move along a bottom surface of the cartridge assembly  36  to assist in moving the anvil  34  to the clamped position and to prevent outward movement of the cartridge assembly  36  during firing of the stapling device  10 . 
       FIGS. 4-6  illustrate the tool assembly  20  including a locking member  86 . The locking member  86  is positioned in the longitudinal slot  45   a  of the channel  45  in abutment with a surface of the staple cartridge  46  and includes an elongated member having a proximal end  90  and a distal end  91  that defines an engagement portion  92 . The proximal end  90  of the locking member  86  is positioned adjacent the clamping member  64  when the clamping member  64  is in a retracted position. 
     When the clamping member  64  is moved from its retracted position to its advanced position ( FIG. 6 ), the clamping member  64  moves within the slot  80  in the anvil  34  and engages the proximal end  90  of the locking member  86  to advance the locking member  86  from a retracted position to an advanced position ( FIG. 6 ). The distal end  91  of the locking member  86  is aligned with the opening  52  in the dissecting tip  50  of the anvil  34  such that when the locking member  86  is moved from its retracted position to its advanced position, the engagement portion  92  of the locking member  86  moves through the opening  52  to a locked position in locking engagement with the dissecting tip  50 . Engagement of the locking member  92  with the dissecting tip  50  of the anvil  34  prevents outward movement of the anvil  34  in relation to the cartridge assembly  36  beyond a predetermined distance to set a pre-determined tissue gap “G” between the anvil  34  and cartridge assembly  36  at a distal end of the tool assembly  20 . 
     In embodiments, the engagement portion  92  of the locking member  86  includes an angled finger that engages the distal portion of the staple cartridge  46  and the distal portion of the dissecting tip  50  to minimize outward movement of the anvil  34  in relation to the staple cartridge  46 . 
     When the surgical stapling device  10  is actuated to move the tool assembly  20  from the open position ( FIG. 3 ) to the clamped position ( FIG. 5 ), the drive member  60  is initially moved in the direction indicated by arrow “A” in  FIG. 6  to advance the clamping member  64  within the cutout  80  of the anvil  34  into engagement with the cam surfaces  82  ( FIG. 5 ) of the anvil  34 . Engagement of the clamping member  64  with the cam surfaces  82  on the anvil  34  moves the tool assembly  20  from the open position ( FIG. 3 ) to the clamped position ( FIG. 6 ). Since the clamping member  64  abuts the proximal end  90  of the locking member  86 , movement of the clamping member  64  in the direction of arrow “A” moves the locking member  86  and the firing member  62  in the direction indicated by arrows “B” to advance the engagement portion  92  of the locking member  86  through the opening  52  in the dissecting tip  50  to lock the dissecting tip  50  to the distal portion of the cartridge assembly  36 . Engagement between the engagement portion  92  of the locking member  86  and the dissecting tip  50  on the distal portion of the anvil  34  sets the tissue gap “G” ( FIG. 6 ) defined between the anvil  34  and the staple cartridge  46  of the tool assembly  20 . 
     When the clamping member  64  reaches the distal end of the slot  80  in the anvil  34 , the clamping member  64  abuts a stop surface  80   a  ( FIG. 6 ) on the anvil  34  to prevent further distal movement of the clamping member  64  and the locking member  86 . When the firing member  62  ( FIG. 4 ) is advanced towards its distal-most position from the position shown in FIG.  6 , the firing member  62  moves independently of the clamping member  64  and the locking member  86  to eject staples from the staple cartridge  46 . 
     As shown, the locking member  86  is associated with the clamping member  64  such that movement of the clamping member  64  moves the tool assembly  20  to the clamped position and subsequently moves the locking member  86  to its locked position. It is envisioned that the association between the locking member  86  and the clamping member  64  can be modified to move the locking member  86  to its locked position as the tool assembly  20  moves to its clamped position. 
     As described above, the locking member  86  is moved to the locked position in response to movement of the clamping member  64 . It is envisioned that a separate actuation mechanism can be used to move the locking member  86  to its locked position independently of the clamping member  64 . 
       FIGS. 7-10  illustrate another embodiment of a locking member for setting the tissue gap of a tool assembly  120 . The tool assembly  120  is similar to tool assembly  20  and will only be described in detail to describe differences between the two assemblies. The tool assembly  120  includes an anvil  134 , a cartridge assembly  136 , and a drive assembly  160 . The anvil  134  includes a dissecting tip  150  that defines a bore  152 . The cartridge assembly  136  includes a staple cartridge  146  that that supports a plurality of staples (not shown) and a pusher  186  that extends through the staple cartridge  146 . The pusher  186  includes a proximal portion  190  and a distal portion  191 . 
     The drive assembly  160  includes a firing member  162  and a clamping member  164  that are as described above in regard to the firing member  62  and the clamping member  64 . The clamping member  164  is aligned with the proximal portion  190  of the pusher  186  such that movement of the clamping member  164  from a retracted position towards an advanced position ( FIG. 9 ) moves the pusher  186  from a retracted position to an advanced position. 
     The staple cartridge  146  includes a locking member  192  that extends through a stepped bore  194  ( FIG. 8 ) defined in the staple cartridge  146 . The locking member  192  includes a proximal portion that is engaged with the distal portion of the pusher  186  such that distal movement of the pusher  186  causes distal movement of the locking member  192 . When the tool assembly  120  is in a clamped position ( FIG. 7 ), the locking member  192  is aligned with the bore  152  in the dissecting tip  150 . A spring  196  is positioned within the stepped bore  194  of the staple cartridge  136  to urge the pin  192  to its retracted position in which a distal end of the locking member  192  is spaced from the bore  152  in the dissecting tip  150 . 
     In embodiments, the locking member  192  may be in the form of an elongate pin that includes a flange  197 . In embodiments, the flange  197  is positioned to engage a shoulder  198  that is defined by a wall defining the stepped bore  194  to prevent proximal movement of the locking member  186  through the stepped bore  194  of the staple cartridge  146 . In embodiments, the elongate pin  192  includes a head  199  and the spring  196  is positioned between the shoulder  198  and the head  199  to urge the elongate pin  192  proximally within the stepped bore  194 . 
       FIGS. 9 and 10  illustrate the tool assembly  120  as the clamping member  164  is advanced in the direction indicated by arrows “D” to move the anvil  134  and the cartridge assembly  136  from the open position to the clamped position ( FIG. 9 ). The tool assembly  120  functions in a similar manner to the tool assembly  20 . More specifically, when the clamping member  164  is advanced within the slot  180  defined in the anvil  134 , the clamping member  164  engages cam surfaces  182  to first move the anvil  134  towards the cartridge assembly  136  to move the tool assembly  120  from the open position to the clamped position. As the clamping member  164  advances, the pusher  186  which is engaged with the clamping member  164  is advanced. The distal end of the pusher  186  is engaged with the locking member  192  such that advancement of the pusher  186  advances the locking member  192  against the bias of the spring  196  into the bore  152  in the dissector tip  150  to lock the distal end of the cartridge assembly  136  in relation to the distal end of the anvil  134 . 
     As described above, the locking member  192  is moved to the locked position in response to movement of the clamping member  164 . It is envisioned that a separate actuation mechanism can be used to move the locking member  192  to its locked position independently of the clamping member  164 . 
       FIGS. 11-15  illustrate another embodiment of a locking member for setting the tissue gap of a tool assembly  220 . The tool assembly  220  is similar to tool assemblies  20  and  120  and will only be described in detail to describe differences between the different assemblies. The tool assembly  220  includes an anvil  234 , a cartridge assembly  236 , and a drive assembly  260 . The anvil  234  includes a dissecting tip  250  that defines a bore  252  and is pivotably supported on the distal portion of the anvil  234  about a pivot member  234   a  ( FIG. 12 ). 
     The cartridge assembly  236  includes a staple cartridge  246  that that supports a plurality of staples (not shown). The drive assembly  260  includes a firing member  262  and a clamping member  264  that are as described above in regard to the firing members  62 ,  162  and the clamping members  64 ,  164 . 
     The anvil  234  supports a pusher  286  that has a proximal portion  290  aligned with the clamping member  264  ( FIG. 13 ) and a distal portion  291  that is aligned with a proximal surface of the dissector tip  250  at a position above the pivot member  234   a  as viewed in  FIG. 13 . When the clamping member  264  is moved from its retracted position ( FIG. 13 ) towards its advanced position, the clamping member  264  engages and moves the pusher  286  from a retracted position to an advanced position. As the pusher  286  moves towards its advanced position, the distal portion  291  of the pusher  286  engages and pivots the tissue dissector  250  about the pivot member  234   a  downwardly, as viewed in  FIG. 15 , towards its locked position engaged with a distal portion  296  of the staple cartridge  246 . In embodiments, the distal end  299  ( FIG. 15 ) of the distal portion  291  of the pusher  286  may be tapered to assist movement of the tissue dissector  250  towards its locked position. 
     The distal portion  296  of the staple cartridge  246  includes projection  296  that is received within the bore  252  of the tissue dissector  250  when the tissue dissector  252  is pivoted to its locked position. In embodiments, a spring  298  is positioned between the proximal surface of the tissue dissector  250  and the distal portion of the anvil  234  to urge the tissue dissector  250  towards its unlocked position ( FIG. 14 ). 
     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 embodiments. It is envisioned that the elements and features illustrated or described in connection with one exemplary embodiment may be combined with the elements and features of another without departing from the scope of this disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the above-described embodiments. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.