Patent Publication Number: US-2022211381-A1

Title: Circular stapling device

Description:
BACKGROUND 
     1. Technical Description 
     The present disclosure is directed to stapling devices and, more particularly, to circular stapling devices that delay cutting of tissue until after staple formation. 
     2. Background of Related Art 
     Conventional manually operated circular stapling devices include an elongate body, a shell assembly that is supported on a distal portion of the elongate body, and an anvil assembly that is movably supported on the distal portion of the elongate body adjacent to the shell assembly. The shell assembly includes a shell housing, a staple cartridge supported on the shell housing, a pusher assembly, and a knife supported on the pusher assembly. The staple cartridge supports a plurality of staples. The pusher assembly includes a staple pushing member that is movable through the staple cartridge to eject the plurality of staples from the staple cartridge through tissue and form the staples against the anvil assembly. The knife is coupled to and movable with the staple pushing member to dissect the tissue clamped between the shell assembly and the anvil assembly during staple formation. 
     SUMMARY 
     One aspect of the disclosure is directed to a circular stapling device including a handle assembly, an elongate body, and a shell assembly. The handle assembly includes a firing trigger. The elongate body is supported by the handle assembly and includes a proximal portion and a distal portion. The shell assembly is supported on the distal portion of the elongate body and includes a shell housing defining a cavity, a staple cartridge, a pusher defining a longitudinal bore, a knife carrier, and a knife. The staple cartridge is supported on the shell housing and supports a plurality of staples. The knife carrier is movable within the longitudinal bore of the pusher and the knife is supported on the knife carrier. The pusher is movable within the cavity of the shell housing from a retracted position to an advanced position to eject the plurality of staples from the staple cartridge. The anvil assembly is supported on the distal portion of the elongate body and is movable in relation to the shell assembly between open and clamped positions. The knife carrier is adapted to releasably engage the pusher and is movable between a retracted position and an intermediate position to move the pusher from its retracted position to its advanced position and subsequently movable from its intermediate position to an advanced position independently of the pusher to advance the knife to cut tissue. 
     In embodiments, the firing trigger is coupled to the knife carrier such that movement of the firing trigger through an actuation stroke moves the knife carrier from its retracted position to its advanced position. 
     In some embodiments, the firing trigger is manually movable through the actuation stroke. 
     In certain embodiments, the knife carrier includes at least one tab that is movable from a first position engaged with the pusher to translate distal movement of the knife carrier to distal movement of the pusher to a second position to allow distal advancement of the knife carrier independently of the pusher. 
     In embodiments, each of the at least one tabs is supported on a resilient arm. 
     In some embodiments, the resilient arm supporting each of the at least one tabs is supported in cantilevered fashion to the knife carrier. 
     In certain embodiments, the shell assembly includes a housing that includes at least one longitudinal rib that is positioned to engage the resilient arm supporting each of the at least one tabs to retain each of the at least one tabs in the first position as the pusher is moved towards its advanced position. 
     In embodiments, one of the pusher and the knife carrier includes a breakable ring and the other of the pusher and the knife carrier includes an annular projection that is positioned to engage the breakable ring. 
     In some embodiments, the breakable ring is adapted to fracture when the pusher nears its advanced position to facilitate movement of the knife carrier independently of the pusher. 
     Another aspect of the disclosure is directed to a shell assembly including a shell housing defining a cavity, a staple cartridge, a pusher defining a longitudinal bore, a knife carrier, and a knife. The staple cartridge is supported on the shell housing and supports a plurality of staples. The knife carrier is movable within the longitudinal bore of the pusher and the knife is supported on the knife carrier. The pusher is movable within the cavity of the shell housing from a retracted position to an advanced position to eject the plurality of staples from the staple cartridge. The knife carrier is adapted to engage the pusher and is movable between a retracted position and an intermediate position to move the pusher from its retracted position to its advanced position and subsequently movable from its intermediate position to an advanced position independently of the pusher to advance the knife to cut tissue. 
     Another aspect of the disclosure is directed to a shell assembly including a shell housing defining a cavity, a staple cartridge, a pusher defining a longitudinal bore, a knife carrier, and a knife. The staple cartridge is supported on the shell housing and supports a plurality of staples. The pusher defines a longitudinal bore and is movable within the cavity of the shell housing from a retracted position to an advanced position to eject the plurality of staples from the staple cartridge. The knife carrier is movable within the longitudinal bore of the pusher and supports the knife, wherein the knife carrier is releasably coupled to the pusher and movable independently of the pusher to cut tissue after staple formation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments of the disclosed stapling device are described herein below with reference to the drawings, wherein: 
         FIG. 1  is a side perspective view of an exemplary embodiment of the disclosed surgical stapling device with an anvil assembly of the stapling device in an open or unclamped position; 
         FIG. 2  is a side perspective exploded view of a distal portion of the surgical stapling device shown in  FIG. 1 ; 
         FIG. 3  is a perspective view from the distal end of the shell housing of the distal portion of the stapling device shown in  FIG. 2 ; 
         FIG. 4  is a side perspective view of a knife carrier of the distal portion of the stapling device shown in  FIG. 2 ; 
         FIG. 5  is a side perspective view of the distal portion of the stapling device shown in  FIG. 1  with a shell housing removed and the anvil assembly in a clamped position; 
         FIG. 6  is a side perspective view of a distal portion of the stapling device shown in  FIG. 1  with the anvil assembly in a clamped position; 
         FIG. 7  is a cross-sectional view taken along section line  7 - 7  of  FIG. 3 ; 
         FIG. 8  is a cross-sectional view taken along section line  8 - 8  of  FIG. 7 ; 
         FIG. 9  is a side cross-sectional view through the distal portion of the stapling device shown in  FIG. 1  with the anvil assembly in the clamped position and the knife carrier advanced to an intermediate position to form staples; 
         FIG. 10  is a side cross-sectional view through the distal portion of the stapling device shown in  FIG. 1  with the anvil assembly in the clamped position and the knife carrier in an advanced position to cut tissue; 
         FIG. 11  is a side perspective cross-sectional view an alternate embodiment of the staple pusher of the stapling device shown in  FIG. 1 ; 
         FIG. 12  is a side perspective view of the knife carrier of the stapling device shown in  FIG. 1 ; 
         FIG. 13  is a side cross-sectional view through a distal portion of the stapling device shown in  FIG. 1  including the pusher of  FIG. 11  and the knife carrier of  FIG. 12  in the clamped position and the knife carrier in the retracted position; 
         FIG. 14  is an enlarged view of the indicated area of detail shown in  FIG. 13 ; 
         FIG. 15  is a side cross-sectional view through a distal portion of the stapling device shown in  FIG. 1  with the anvil assembly in the clamped position and the knife carrier advanced to a position in which the staples are formed and tissue begins to be cut; and 
         FIG. 16  is an enlarged view of the indicated area of detail shown in  FIG. 15 . 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The disclosed 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 present 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 present 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. 
     The disclosed circular stapling device is a manually operated stapling device that includes a manually operated trigger that is adapted to allow staple formation to occur prior to cutting of tissue during a single actuation of the firing trigger. The stapling device minimizes stretching and movement of tissue during staple formation to improve staple formation. The stapling device also reduces the amount of force required to move the firing trigger through a firing stroke by separating the staple formation and tissue cutting functions of the stapling device to reduce stress on a clinician&#39;s hand during actuation of the stapling device. 
       FIG. 1  illustrates an exemplary embodiment of the disclosed circular stapling device shown generally as stapling device  10 . The stapling device  10  includes a handle assembly  12 , an elongate body  14 , a shell assembly  16 , and an anvil assembly  18  that is supported for movement in relation to the shell assembly  16  between spaced and approximated positions as described below. The anvil assembly  18  has an anvil shaft  19  that is adapted to be releasably coupled to an approximation mechanism (not shown) of the stapling device  10  as is known in the art. The elongate body  14  has a distal portion  14   a  and a proximal portion  14   b . In embodiments, the shell assembly  16  includes a proximal portion  20  that is releasably coupled to the distal portion  14   a  of the elongate body  14 . Alternately, the shell assembly  16  can be fixedly secured to the elongate body portion  14 . 
     The handle assembly  12  includes a stationary grip  22  that supports a firing trigger  24  and an approximation knob  25 . The approximation knob  25  is actuable to move the anvil assembly  18  in relation to the shell assembly  16  between open and clamped positions. The firing trigger  24  is movable through an actuation stroke to control operation of various functions of the stapling device  10  including firing of staples from the shell assembly  16  and cutting or coring of tissue. 
       FIG. 2  illustrates the shell assembly  16  of the stapling device  10  shown in  FIG. 1 . The shell assembly  16  includes a shell housing  30 , a pusher  32 , a knife carrier  34 , an annular knife  36  supported on the knife carrier  34 , a staple cartridge  38 , and a plurality of staples  40  supported within the staple cartridge  38 . The staple cartridge  38  is annular and defines annular rows of staple pockets  42 . Each of the staple pockets  42  supports one of the plurality of staples  40 . The pusher  32  includes a body  44  that defines a longitudinal bore  44   a  and includes a distal portion having a plurality of fingers  46 . Each of the plurality of fingers  46  is received within and movable through a respective one of the staple pockets  42  of the staple cartridge  38  to eject the staples  40  from the staple pockets  38  when the pusher  32  is moved within the shell housing  30  from a retracted position to an advanced position. 
       FIG. 3  illustrates the shell housing  30  of the shell assembly  16 . The shell housing  16  includes an outer housing portion  50  and an inner housing portion  52  that are spaced from each other to define an annular cavity  54 . The inner housing portion  52  of the shell housing  30  defines a through bore  56  that receives the anvil shaft  19  ( FIG. 1 ) of the anvil assembly  18  when the anvil assembly  18  is moved to the clamped position to align the anvil assembly  18  with the staple cartridge  38  of the shell assembly  16 . The inner housing portion  52  includes an outer surface supporting longitudinal ribs  58  that are positioned within the annular cavity  54  of the shell housing  16 . The shell housing  30  also includes struts  59  that extend between the inner housing portion  52  and the outer housing portion  50 . The struts  59  confine the knife carrier  34  to longitudinal movement within the shell housing  30  as described in detail below. 
     The knife carrier  34  is received within the annular cavity  54  of the shell housing  30  and within the pusher  32  and includes an annular body  60 . The annular body  60  defines a longitudinal through bore  60   a  and has a distal portion  62  and a proximal portion  64 . In embodiments, the distal portion  62  defines an annular recess  66  that receives the proximal end of the annular knife  36  to secure the knife  36  to the knife carrier  34 . The knife  36  may also have tabs  70  ( FIG. 2 ) that engage the knife carrier  34  to further secure the knife  36  to the knife carrier  34 . Alternately other securement techniques can be used to secure the knife  36  to the knife carrier  34 . 
     The proximal portion  64  of the annular body  60  of the knife carrier  36  is defined by spaced legs  74  that are separated by longitudinal slots  76 . When the knife carrier  34  is received in the annular cavity  54  of the shell housing  30 , the longitudinal slots  76  receive the struts  59  of the shell housing  30  to confine the knife carrier  34  to longitudinal movement within the shell housing  30 . A proximal portion of the annular body  60  of the knife carrier  34  supports coupling members  86 . The coupling members  86  are adapted to engage a drive member (not shown) supported within the elongate body  14  to couple the knife carrier  34  to the firing trigger ( FIG. 1 ). 
       FIG. 5  illustrates the distal portion of the knife carrier  34  with the knife carrier received within longitudinal bore  44   a  of the pusher  32 . As illustrated, the annular body  60  of the knife carrier  34  supports one or more resilient cantilevered arms  80 . In embodiments, each of the arms  80  has a distal end supported by the annular body  60  and a distal end that supports a tab  82 . The tabs  82  extend radially outward from the arms  80  and are positioned to engage a proximal portion of the pusher  32  such that movement of the knife carrier  34  effects distal movement of the pusher  32  within the annular cavity  54  of the shell housing  30  between a retracted position and an advanced position as described in further detail below. The cantilevered arms  80  of the knife carrier  34  are resilient and can flex inwardly into the longitudinal through bore  60   a  of the knife carrier  34  when the pusher  32  has reached its advanced position to allow the knife carrier  34  to move distally independently of the pusher  32  after staple formation to cut tissue. The tabs  82  may be positioned to engage the proximal end of the pusher  32 . Alternately, other configurations are envisioned. As shown in  FIG. 5 , the proximal portion of the pusher  32  may include elongated slots or notches  84 . The notches  84  receive the struts  59  ( FIG. 3 ) of the shell housing  30  to properly align the pusher  32  within the shell housing  30 . 
       FIGS. 5-8  illustrate the distal portion of the stapling device  10  with the anvil assembly  18  in the clamped position about tissue “T” prior to actuation of the firing trigger  24  ( FIG. 1 ). In this position, the knife carrier  34  and the pusher  32  are in their retracted positions within the shell housing  30 . The cantilevered arms  80  of the knife carrier  32  are supported on the longitudinal ribs  58  of the inner housing portion  52  of the shell housing  30 . When the cantilevered arms  80  are supported on the longitudinal ribs  58 , the arms  80  are deformed outwardly from the knife carrier  34  to urge the tabs  82  outwardly into longitudinal alignment and/or engagement with the pusher  32 . 
       FIG. 9  illustrates the stapling device  10  with the anvil assembly  18  in the clamped position about the tissue “T” as the firing trigger  24  ( FIG. 1 ) is moved through an actuation stroke and the staples  40  are formed in the tissue “T”. Initially, when the firing trigger  24  is actuated, the knife carrier  34  is advanced in the direction indicated by arrows “A”. As the knife carrier  34  is advanced, the tabs  82  on the cantilevered arms  80  engage the pusher  32  to advance the pusher  32  with the knife carrier  34  in the direction indicated by arrows “B”. As the pusher  32  moves distally within the shell housing  30 , the fingers  46  of the pusher  32  pass through the staple pockets  42  of the staple cartridge  38  to advance and form the staples  40  against the anvil assembly  18 . In this position, the knife  36  has yet to engage the tissue “T”. Alternately, the knife  36  may be in contact with the tissue “T” as staple formation is completed. 
     As illustrated in  FIG. 10 , when the knife carrier  34  advances in the direction indicated by arrows “A” to a position in which the cantilevered arms  80  of the knife carrier  34  pass off of distal ends  96  of the longitudinal ribs  58  on the inner housing portion  52  of the shell housing  30 , the cantilevered arms  80  move inwardly due to the resilience of the arms  80  such that the tabs  82  disengage from the pusher  32 . When this occurs, the knife carrier  34  will advance or move distally independently of the pusher  32  to advance the knife  36  in the direction of arrows “C” to cut the tissue “T”. The distal ends of the tabs  82  may include a chamfer  98  to allow engagement between the tabs  82  and the pusher  32  to assist in moving the arms  80  inwardly to facilitate separation of the tabs  82  and the pusher  32 . 
     As discussed briefly above, separating the two functions of the stapling device  10 , i.e., staple formation and cutting, allows the forces required to actuate the firing trigger  24  of the stapling device  10  to be reduced and minimizes pulling or stretching of tissue during staple formation to improve staple formation. 
       FIGS. 12-16  illustrate another exemplary embodiment of the disclosed stapling device  10  ( FIG. 1 ) which is similar to the embodiment described above with the exception of modifications to the pusher  132  and the knife carrier  134  which are described in further detail below. 
     The pusher  132  is substantially identical to the pusher  32  ( FIG. 2 ) except that the inner wall of the pusher  32  includes a frangible or breakable ring  132   a  ( FIG. 11 ) that projects into the longitudinal bore  144   a  of the pusher  132 . In addition, the knife carrier  134  is substantially similar to the knife carrier  34  except that the cantilevered arms  80  are eliminated and a projection, such as an annular ring  180  ( FIG. 12 ), is formed on the distal portion  162  of the knife carrier  134 . 
       FIG. 13  illustrates the distal portion of the stapling device  10  ( FIG. 1 ) with the anvil assembly  18  in the clamped position about tissue “T” prior to actuation of the firing trigger  24  ( FIG. 1 ). In this position, the knife carrier  134  and the pusher  132  are in their retracted positions within the shell housing  30 . The projection on the knife carrier  134 , e.g., annular ring  180 , is positioned immediately proximal to and in alignment with the breakable ring  132   a  of the pusher  132 . Although the annular ring  180  of the knife carrier  134  is shown engaged with the breakable ring  132   a , the two components need only be aligned with each other prior to actuation of the firing trigger  24  ( FIG. 1 ). 
       FIGS. 15 and 16  illustrate the stapling device  10  with the anvil assembly  18  in the clamped position about the tissue “T” as the firing trigger  24  ( FIG. 1 ) is moved through an actuation stroke. Initially, when the firing trigger  24  ( FIG. 1 ) is actuated the knife carrier  134  is advanced in the direction indicated by arrows “D”. As the knife carrier  134  is advanced, the annular ring  180  on the knife carrier  134  engages the breakable ring  132   a  on the pusher  132  to advance the pusher  132  with the knife carrier  34  in the direction indicated by arrows “D”. As the pusher  132  moves distally within the shell housing  30 , the fingers  146  of the pusher  132  passes through the staple pockets  42  of the staple cartridge  38  to advance and form the staples  40  against the anvil assembly  18 . In this position, the knife  136  has yet to engage the tissue “T”. Alternately, the knife  136  may be in contact with the tissue “T” as staple formation is completed. 
     When the staple formation is completed, advancement of the pusher  132  is obstructed via engagement between the staple cartridge  38  and the pusher  132 . When this occurs, the force applied to the breakable ring  132   a  of the pusher  132  by the annular ring  180  of the knife carrier  132  increase beyond a threshold force and the breakable ring  132   a  is sheared from the inner wall of the pusher  132  to allow the knife carrier  132  to move distally independently of the pusher  132  in the direction indicate by arrows “E” to cut the tissue “T”. 
     As discussed briefly above, separating the two functions of the stapling device  10 , i.e., staple formation and cutting, allows the forces required to actuate the firing trigger  24  of the stapling device  10  to be reduced and minimizes pulling or stretching of tissue during staple formation to improve staple formation. 
     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 the present 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.