Abstract:
A surgical stapler is provided having a cartridge arm for holding staples, an anvil pivotally connected thereto to deform fired staples from the cartridge arm, and a support for substantially preventing anvil deflection during staple firing to help insure proper staple formation. Some supports allow pivoting between the anvil and cartridge arm when in a first position, but prevent or hinder the pivoting action when in a second position. Supports can also be adapted to contact the anvil at a distal position relative to the pivot point between the anvil and cartridge arm. Exemplary structures of supports embodied as one or more links or as a sleeve are described. Methods of use are also discussed.

Description:
FIELD OF THE INVENTION 
     The present invention relates broadly to surgical devices, and in particular to a surgical stapler and/or cutter having a support for an end effector. 
     BACKGROUND OF THE INVENTION 
     Endoscopic and laparoscopic surgical instruments are often preferred over traditional open surgical devices since the use of natural orifices (endoscopic) or smaller incisions (laparoscopic) tends to reduce the post-operative recovery time and complications. Consequently, significant development has gone into a range of endoscopic and laparoscopic surgical instruments that are suitable for precise placement of a distal end effector at a desired surgical site. These distal end effectors engage the tissue in a number of ways to achieve a diagnostic or therapeutic effect (e.g., endocutter, grasper, cutter, staplers, clip applier, access device, drug/gene therapy delivery device, and energy device using ultrasound, RF, laser, etc.). 
     Typically, endoscopic and laparoscopic surgical staplers have a stapling mechanism, the end effector, which is adapted to fit through a cannula to position the end effector relative to tissue to be stapled. The end effector has a cartridge arm containing a cartridge with staples, and an anvil that is pivotally connected to the cartridge arm. The cartridge arm and anvil each act as a separate jaw to close and hold together the tissue to be stapled. Upon cartridge actuation, staples are driven from the cartridge arm, through the tissue, and against staple-forming grooves formed in the anvil and aligned with the staples of the cartridge arm, thus forming the staples that hold the tissue together. 
     When a stapler simultaneously fires multiple staples in a linear arrangement, deflection of the anvil can occur. In particular, the force required to drive the staples along with relatively long unsupported length of the anvil can create substantial torque at the anvil&#39;s distal end, resulting in deflection. This can result in malformed staples, especially toward the distal end of relatively long end effectors. Since endoscopic or laparoscopic procedures utilize small orifices or access ports, the thickness or outer diameter of the end effector is necessarily limited. Even with the use of very stiff materials for the anvil (e.g., steel or titanium), deflection is still noticeable upon stapler actuation. 
     Accordingly, a need exists for improved devices and methods for stapling and/or cutting tissue. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention generally provides methods and devices for supporting an anvil on a surgical stapler and/or cutter. In one embodiment the surgical stapler can include an end effector having a cartridge arm to hold one or more staples, and an anvil pivotally coupled to the cartridge arm and effective to deform staples. The device can also include a support adapted to contact the end effector and reduce deflection of the anvil when one or more staples are driven from the cartridge arm and deformed against the anvil. In an exemplary embodiment, the cartridge arm can be adapted to hold a plurality of staples in at least one linear row. The end effector and support can also, in other embodiments, have a maximum outer diameter that is less than about 16 mm when the support is in a collapsed position to allow the end effector to fit within small orifices or cannulas. 
     The support can have a variety of configurations, but in one embodiment it can be adapted to contact the anvil at a location distal to the pivot point. For example, the support can be slidably coupled to the anvil, and movable between a proximal position in which the anvil can move about the pivot point, and a distal position in which the support prevents the anvil from moving about the pivot point. In an exemplary embodiment, the support can include at least two linkages pivotally coupled to one another, with one of the linkages being slidably coupled to the anvil. In particular, the support can include a distal linkage slidably coupled to the anvil, a proximal linkage pivotally coupled at one end to the distal linkage and at an opposite end to an elongate shaft extending proximally from the cartridge arm, and a middle-linkage pivotally coupled at one end to the elongate shaft and pivotally coupled at an opposite end to the distal linkage and the proximal linkage. In another embodiment, the support can be in the form of a sleeve that is movable between a first position in which the anvil is pivotable relative to the cartridge arm and a second position in which the anvil is prevented from pivoting relative to the cartridge arm. In other embodiments, the device can include a stop member for limiting distal movement of the support. For example, the anvil can include at least one elongate slot for slidably receiving at least one pin member formed on the support. The slot can terminate at a substantial mid-portion of the anvil to limit distal movement of the support. 
     Exemplary methods for stapling tissue are also provided. In one embodiment, the method can include positioning tissue between a cartridge arm and an anvil of a surgical stapler, and advancing a support relative to the anvil to prevent deflection of the anvil relative to the cartridge arm when one or more staples are driven from the cartridge, through tissue positioned between the anvil and the cartridge arm, and are deformed against the anvil to staple the tissue. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a side view of a surgical stapler according to one embodiment of the invention; 
         FIG. 2A  is a perspective view of the end effector of the surgical stapler of  FIG. 1 , showing one embodiment of a support in a collapsed position, and the anvil pivoted away from the cartridge arm; 
         FIG. 2B  is a perspective view of the end effector of  FIG. 2A , showing the support in a collapsed position, and the anvil and cartridge arm pivoted together; 
         FIG. 2C  is a perspective view of an end effector of  FIG. 2A , showing the support in a partially extended position relative to the anvil; 
         FIG. 2D  is a perspective view of the end effector of  FIG. 2A , showing the support in a fully extended position to prevent deflection of the anvil; 
         FIG. 3A  is a perspective view of another embodiment of an end effector of a surgical stapler, having an anvil pivotally coupled to a cartridge arm, and a support sleeve in a proximal position to allow the anvil to pivot away from the cartridge arm; 
         FIG. 3B  is a perspective view of the end effector of  FIG. 3A , showing the anvil and cartridge arm pivoted toward one another, and the support sleeve advanced toward a distal position to hinder movement of the anvil; and 
         FIG. 3C  is a perspective view of a handle portion of the surgical stapler shown in  FIG. 3A , showing a lever for moving the support sleeve between the proximal and distal positions. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In general, a surgical stapler and/or cutter is provided having an end effector for delivering staples to tissue, and a support for preventing deflection of the end effector. In particular, the end effector can include a cartridge arm adapted to hold staples, and an anvil pivotally coupled to the cartridge arm and adapted to deform staples driven from the cartridge arm. The support can be coupled to the end effector and it can be movable between a first, collapsed position in which the anvil arm can pivot relative to the cartridge arm, and a second, extended position in which the support engages the anvil to substantially limit deflection of the anvil when one or more staples are driven from the cartridge arm and deformed against the anvil. The support is particularly effective for use with linear surgical staplers and/or cutters having a relatively long end effector for delivering one or more linear rows or lines of staples, as the support can substantially prevent deflection of a distal end of the anvil during application of long lines of staples. For example, the surgical stapler can have an end effector that has a length that is in the range of about 60 mm to 90 mm. The support is also particularly effective for use in endoscopic and laparoscopic procedures, as the support can be capable of collapsing to allow the end effector and support to be introduced through natural orifices (e.g., the throat) or through small access ports, such as cannulas or other small pathways. For example, in an exemplary embodiment the end effector and support can have a maximum outer diameter that is less than about 16 mm when the support is in a collapsed position to allow the support to be inserted through pathways having a diameter of about 16 mm or less. A person skilled in the art will appreciate that the support can be used with a variety of fastener delivery devices, and that the linear stapler disclosed herein is merely shown for reference purposes. 
       FIG. 1  illustrates one exemplary embodiment of a surgical stapler  10  having a support  30  for limiting or preventing deflection of an anvil. As shown, the device  10  generally includes a handle  14  having an elongate shaft  12  extending therefrom, and including proximal and distal ends  12   a ,  12   b . A shaft housing  13  is shown disposed over a portion of the elongate shaft  12 . A staple applying assembly or end effector  20  is formed on the distal end  12   b  of the elongate shaft  12 . The end effector  20  includes opposed arms, referred to as a cartridge arm  24  and an anvil  22 , that are pivotally coupled to one another at their proximal ends by a pivot point  26 , and that are adapted to receive tissue therebetween. The cartridge arm  24  is adapted to contain a staple cartridge having multiple staples disposed therein and configured to be driven into tissue, and the anvil  22  includes a plurality of grooves formed therein for deforming the staples. The device  10  can also include one or more triggers coupled thereto for actuating the end effector  20 , e.g., opening and closing opposed jaws of the end effector, and/or driving a cutting blade through the end effector  20 .  FIG. 1  illustrates a first trigger  14   a  movably coupled to the handle  14  for closing the opposed jaws of the end effector  20 . The handle  14  also includes a second trigger  14   b  movably coupled thereto for firing the staple cartridge to deliver one or more staples into tissue. The second trigger  14   b  can also be effective to advance a blade distally through the staple cartridge to cut stapled tissue. While two triggers  14   a ,  14   b  are shown, the handle  14  can additionally or alternatively include other actuation mechanisms, such as a rotatable knob, lever, sliding knob, etc. for actuating the end effector  20 . A person skilled in the art will appreciate that the device can include a variety of other features not disclosed herein. For example, the device can include an articulation joint formed between the elongate shaft  12  and the end effector  20  for allowing angular movement of the end effector  20  relative to the elongate shaft  12 . A trigger or other mechanism can be provided on the handle for angularly adjusting the end effector  20 . 
     The support  30  is shown in more detail in  FIGS. 2A-2D . As shown, the support  30  is in the form of a linkage assembly that is movably coupled between the elongate shaft  12  and the anvil  22 . In particular, the support  30  includes a proximal linkage  32 , a distal linkage  34 , and a middle linkage  36  which are pivotally coupled to one another and which are movable relative to the elongate shaft  12  and end effector  20 . The proximal linkage  32  has a proximal end  32   a  ( FIG. 2D ) that is pivotally and slidably coupled to a portion of the elongate shaft  12 , and a distal end  32   b  that is pivotally coupled to a proximal end  34   a  of the distal linkage  34 . The distal linkage  34  extends distally from the distal end  32   b  of the proximal linkage  32 , and it includes a distal end  34   b  that is pivotally and slidably coupled to the anvil  22 . The sliding and pivoting connection between the proximal end  32   a  of the proximal linkage  32  and the elongate shaft  12   b , and between the distal end  34   b  of the distal linkage  34  and the anvil  22 , can be formed using a variety of techniques. For example, the proximal linkage  32  can be coupled to a portion of the elongate shaft  12  that slides, e.g., a sliding push rod  50  ( FIG. 2D ), and that allows pivotal movement of the proximal linkage  32  relative thereto. The distal linkage  34  can include a pin member that slides within a slot  22   c  formed in the anvil, and that allows pivotal movement of the distal linkage  34  relative to the anvil  22 . As indicated above, the support  30  can also include a middle linkage  36 . As shown in  FIGS. 2C and 2D , the middle linkage  36  is pivotally coupled at a first end  36   a  to the distal end  32   b  of the proximal linkage  32  and to the proximal end  34   a  of the distal linkage  34 , such that all three links  32 ,  34 ,  36  are pivotally coupled to one another at a mid-portion of the support  30 . The second end  36   b  of the middle linkage  36  is pivotally coupled to the elongate shaft  12  at a fixed pivot point  36   c , such that the middle linkage  36  cannot slide relative to the elongate shaft  12 . 
     In use, the connection between linkages  32 ,  34 ,  36  allow the support  30  to move between a proximal, collapsed position in which the anvil  22  can pivot relative to the cartridge arm  24 , and a distal, extended position in which the support  30  is effective to limit or prevent deflection of the anvil  22  when one or more staples are driven from the cartridge arm  24  and deformed against the anvil  22 . The proximal, collapsed position in shown in  FIGS. 2A and 2B , and as shown the linkages  32 ,  34 ,  36  are substantially axially aligned with the end effector  20  such that the maximum outer diameter of the elongate shaft  12 , end effector  20 , and support  30  is substantially constant along a length thereof to allow the distal portion of the device  10  to be introduced through a small pathway, e.g., 16 mm or less in diameter. In particular, the proximal linkage  32  is fully retracted in a proximal direction, e.g., using a trigger or other mechanism formed on the handle of the stapler as will be discussed in more detail below, to pull the distal linkage  34  in a proximal direction such that the distal end  34   b  of the distal linkage  34  is in a proximal-most position relative to the anvil  22 . Proximal retraction of the proximal linkage  32  also pivots the first end  36   a  of the middle linkage  36  (not shown in  FIGS. 2A and 2B ) in a proximal direction, such that the middle linkage  36  is received within an opening formed in the elongate shaft  12 . In this position, the anvil  22  is free to open and close relative to the cartridge arm  24 .  FIG. 2A  illustrates the anvil  22  in an open position for receiving tissue therebetween, and  FIG. 2B  illustrates the anvil  22  in a closed position for engaging tissue therebetween. A separate closure mechanism can be used to move the anvil  22  to the closed position, shown in  FIG. 2B , or alternatively the support  30  can be used to urge the anvil  22  toward the cartridge arm  24  when the support  30  is moved to the distal, extended position. 
     The support  30  is shown in the distal, extended position in  FIGS. 2C and 2D . As shown, the proximal linkage  32  is advanced, e.g., using a trigger or other mechanism formed on the handle of the stapler as will be discussed in more detail below, in a distal direction toward the end effector  20 . The distal movement of the proximal linkage  32  will cause the first end  36   a  of the middle linkage  36  to pivot about the fixed pivot point  36   c  formed between the second end  36   b  of the middle linkage  36  and the elongate shaft  12 . As the first end  36   a  of the middle linkage  36  moves away from the elongate shaft  12  and pivots about the fixed pivot point  36   c , the proximal end  34   a  of the distal linkage  34  will likewise move away from, i.e., rotate relative to, the elongate shaft  12 , and the distal end  34   b  of the distal linkage  34  will slide distally within the elongate slot  22   c  formed in the anvil  22 . When the distal linkage  34  reaches a distal-most position, the force imparted to the proximal linkage  32  no longer advances the distal linkage  34  but rather results in a downward force applied by the distal linkage  34  to the anvil  22  to limit or prevent deflection of the anvil  22  relative to the cartridge arm  24  when staples are being driven from the cartridge arm  24  against the anvil  22 . 
     While the support  30  can engage any portion of the anvil  22 , in an exemplary embodiment, the support  30  can be adapted to engage a substantial mid-portion of the anvil  22 . Such a configuration can ensure that the distal linkage  34  applies a downward force on the anvil  22 , which can optionally be effective to move the anvil to the closed position. Engagement of the mid-portion of the anvil  22  can be achieved using, for example, a stop member to limit distal movement of the support  30  relative to the anvil  22 . In the embodiment shown in  FIGS. 2C and 2D , an endpoint  22   d  of the elongate slot  22   c  formed in the anvil  22  functions as a stop member, as the slot  22   c  terminates proximal to the distal-most end of the anvil  22 . Thus, the endpoint  22   d  will prevent the distal linkage  34  from sliding distally beyond the distal-most end of the slot  22   c , thereby causing the distal linkage  34  to engage the mid-portion of the anvil  22 . The endpoint of the slot can also be adjustable using a movable stop pin. The slot can include a number of positions in which a stop pin can be inserted, and the position of the stop pin can determine the extent to which the distal linkage can slide toward the distal end of the anvil before no further sliding can occur. A person skilled in the art will appreciate that a variety of other techniques can be used to create stops or other mechanisms that limit distal movement of the support. 
     As previously indicated, a variety of techniques can be used to move the support  30  between the proximal and distal positions. For example, in one embodiment the proximal linkage can be pivotally coupled to a push rod  50  ( FIG. 2D ) extending through the elongate shaft  12  and adapted to slidably move relative to the elongate shaft  12  to advance and retract the proximal linkage  32 , thereby moving the support  30  between the proximal and distal positions. A lever, trigger, or other mechanism formed on the handle of the device can be provided for effecting movement of the pusher rod  50 . A person skilled in the art will appreciate that movement of the support and/or the pivoting of the anvil and cartridge arm can be accomplished simultaneously or independent of one another, and independent of firing the staples from the cartridge arm  34 . 
     The support can also have a variety of other configurations to prevent deflection of an anvil on a surgical stapler. In another embodiment, as shown in  FIGS. 3A-3C , the support can be in the form of a sleeve that is moveable between a first position and a second position relative to an end effector. As shown, the surgical stapler  300  generally includes an elongate shaft  310  having an end effector formed on a distal end thereof and including an anvil  320  and a cartridge arm  330  pivotally coupled thereto. A sleeve  340  is slidably disposed within the outer housing of the elongate shaft  310 , and it is movable between a proximal, retracted position (shown in  FIG. 3A ) and a distal, extended position (shown in  FIG. 3B ). The sleeve  340  can have a variety of shapes and sizes, and it can be substantially tubular or, as shown in  FIGS. 3A and 3B , it can have a generally elongate shape with a substantially semi-circular cross-section. When the sleeve  340  is in the proximal position, as shown in  FIG. 3A , the sleeve  340  is fully retracted relative to the anvil  320  such that it allows the anvil  320  to pivot relative to the cartridge arm  330 . When the sleeve  340  is advanced to distal position, the sleeve  340  slides over and contacts the anvil  320  at a location distal to the pivot point  350 , thereby hindering or preventing pivotal movement between the anvil  320  relative to the cartridge arm  330 . Accordingly, when a staple is fired, the sleeve  340  limits or prevents deflection of the anvil  320 . 
     As with the embodiment shown in  FIGS. 2A-2D , movement of the support sleeve  340  can be achieved in a variety of manners. In one embodiment, as shown in  FIG. 3C , the handle  370  of the device  300  includes a slide button  360  formed thereon and coupled to a proximal end of the sleeve  340 . Thus, movement of the slide button  360  between proximal and distal positions is effective to move the sleeve  340  between proximal and distal positions. 
     A person skilled in the art will appreciate that the sleeve can have a variety of other configurations, and it does not need to move between a retracted and extended position. For example, a sleeve can be rotatable between a first position in which the sleeve is adjacent to the cartridge arm and allows pivoting of the anvil and cartridge arm, and a second position in which the sleeve is adjacent to the anvil and limits or prevents anvil pivoting with respect to the cartridge arm. 
     Exemplary methods for stapling tissue are also provided. In one exemplary embodiment, the method can include introducing an end effector of a surgical stapler into a surgical site. The end effector can be inserted endoscopically through a natural orifice, or it can be introduced laparoscopically through a small incision or access port, such as a cannula. The end effector is preferably introduced with the support in a retracted position in which the outer diameter of the elongate shaft of the device is at its smallest or kept to a minimum. For example, with regard to the device  10  shown in  FIGS. 2A-2D , the support  30  is preferably introduced in a proximal, collapsed position. With regard to the embodiment shown in  FIGS. 3A-3C , the support sleeve  340  can be introduced in either position, as the sleeve  340  does not increase an outer diameter of the device. 
     Once the end effector is positioned adjacent to tissue to be stapled, anvil and cartridge arm are manipulated to position the tissue therebetween. The anvil is then pivoted toward the cartridge arm, e.g., using the support or using a separate closure mechanism, to engage the tissue between the anvil and cartridge arm. If the support is not used to close the anvil, the support can then be advanced to hinder or prevent movement of the anvil relative to the cartridge arm. The tissue can optionally be squeezed for a period of time to induce “milking” of the tissue, and then the end effector can be actuated to drive staples from the cartridge arm, through the tissue between the anvil and cartridge arm, and against the anvil. The staples will deform against the anvil, and the support will prevent deflection of the anvil. 
     One skilled in the art will appreciate further features and advantages of the invention based on the above-described embodiments. Accordingly, the invention is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.