Abstract:
One example of a surgical apparatus may include a feeder belt, a plurality of staples frangibly connected to the feeder belt, and at least one pull tab extending laterally from the feeder belt. An example of a surgical method of treating tissue within the body of a patient may include providing at least one feeder belt and staples frangibly connected thereto, and at least one wedge movable relative to the feeder belt; moving at least one wedge in a first direction to contact and thereby form and shear at least one staple from at least one feeder belt; and moving at least one wedge in a second direction to engage and advance the feeder belt.

Description:
FIELD OF THE INVENTION 
     The invention generally relates to surgical staples and stapling. 
     BACKGROUND 
     An endocutter is a surgical tool that staples and cuts tissue to transect that tissue while leaving the cut ends hemostatic. An endocutter is small enough in diameter for use in minimally invasive surgery, where access to a surgical site is obtained through a trocar, port, or small incision in the body. A linear cutter is a larger version of an endocutter, and is used to transect portions of the gastrointestinal tract. A typical endocutter receives at its distal end a disposable single-use cartridge with several rows of staples, and includes an anvil opposed to the cartridge. The surgeon inserts the endocutter through a trocar or other port or incision in the body, orients the end of the endocutter around the tissue to be transected, and compresses the anvil and cartridge together to clamp the tissue. Then, a row or rows of staples are deployed on either side of the transection line, and a blade is advanced along the transection line to divide the tissue. 
     During actuation of an endocutter, the cartridge fires all of the staples that it holds. In order to deploy more staples, the endocutter must be moved away from the surgical site and removed from the patient, after which the old cartridge is exchanged for a new cartridge. The endocutter is then reinserted into the patient. However, it can be difficult and/or time-consuming to located the surgical site after reinsertion. Further, the process of removing the endocutter from the patient after each use, replacing the cartridge, and then finding the surgical site again is tedious, inconvenient and time-consuming, particularly where a surgical procedure requires multiple uses of the endocutter. That inconvenience may discourage surgeons from using the endocutter for procedures in which use of an endocutter may benefit the patient. Similar inconveniences may accompany the use of surgical staplers other than endocutters. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an exemplary feeder belt. 
         FIG. 2  is a side view of an exemplary end effector of a surgical stapler that utilizes the feeder belt of  FIG. 1 . 
         FIG. 3  is a top view of the staple holder of the end effector of  FIG. 2 . 
         FIG. 4  is a perspective view of an actuation assembly. 
         FIG. 5  is a side view of the actuation assembly of  FIG. 4  in a first position within the staple holder of  FIG. 3 . 
         FIG. 6  is a side view of the actuation assembly of  FIG. 4  in a second position within the staple holder of  FIG. 3 . 
         FIG. 7  is a side view of the actuation assembly of  FIG. 4  in a third position within the staple holder of  FIG. 3 . 
         FIG. 8  is a side view of the knife of the actuation assembly of  FIG. 4  in a first position within the staple holder of  FIG. 3 . 
         FIG. 9  is a side view of the knife of the actuation assembly of  FIG. 4  in a second position within the staple holder of  FIG. 3 . 
         FIG. 10  is a side view of a tensioning tab of the staple holder of  FIG. 3  engaging the feeder belt of  FIG. 1 . 
     
    
    
     The use of the same reference symbols in different figures indicates similar or identical items. 
     DETAILED DESCRIPTION 
     U.S. patent application Ser. No. 11/851,379, filed Sep. 6, 2007; U.S. patent application Ser. No. 11/956,988, filed Dec. 14, 2007; U.S. patent application Ser. No. 12/263,171, filed Oct. 31, 2008 (the “Endocutter Documents”) are hereby incorporated by reference herein in their entirety. The Endocutter Documents describe a surgical stapler that includes an end effector attached to a shaft, which in turn is attached to a handle. The Endocutter Documents also describe a feeder belt extending into the end effector, where staples extend from and are frangibly connected to the feeder belt. 
     Referring to  FIG. 1 , a feeder belt  2  is provided, from which one or more staples  4  extend. A frangible connection between the feeder belt  2  and each corresponding staple  4  may be made in any suitable manner. The feeder belt  2  and staples  4  may be configured substantially as described in the Endocutter Documents. At least one pull tab  6  may extend laterally outward from at least one feeder belt  2  in at least one lateral direction. The tab  6  may extend laterally outward from the feeder belt  2  laterally both left and right, as shown in  FIG. 1 , or may extend laterally in only a single direction. The pull tab  6  may be longitudinally spaced apart from staples  4  proximal and/or distal to the pull tab  6 . The pull tab  6  may be substantially the same thickness as the feeder belt  2 . 
     One or more rows  8  of staples  4  may be connected to the feeder belt  2 . Each row  8  of staples  4  is the group of staples  4  positioned at substantially the same lateral location relative to the longitudinal centerline of the feeder belt  2 . At least two longitudinally-adjacent staples  4  in each row  8  may be spaced apart a distance different from the distance between two other longitudinally-adjacent staples  4 . Consequently, the staples  4  in each row  8  may be grouped together in two or more separate groups  10 . Each group  10  of staples  4  in a row  8  may be separated from a longitudinally adjacent group  10  of staples  4  by a blank space  12  on the feeder belt  2 , where that blank space may have any suitable length. Advantageously, no staples  4  extend from, or into an area bounded by, the blank space  12  of the feeder belt  2 . At least one pull tab  6  may be positioned in a blank space  12 . Advantageously, a pull tab  6  is located in each blank space  12  between groups  10  of staples  4 , and a pull tab  6  is located distal to the distalmost group  10  of staples  4  on the feeder belt  2 . 
     Referring also to  FIG. 2 , the end effector  20  may include a staple holder  24  and an anvil  22  positioned at the distal end of a shaft  26 . One or more feeder belts  2  extend into a space defined within the staple holder  24 , such as set forth in the Endocutter Documents. Referring also to  FIG. 3 , a thin piece of material may be an upper plate  28  of the staple holder  24 . The upper plate  28  of the staple holder  24  may includes a number of apertures  30  defined therethrough. The apertures  30  are aligned with the positions of the corresponding staples  4  in the staple holder  24 , such that staples  4  are deployed out of the staple holder  24  through the apertures  30 . A tensioning tab  32  may be defined in the upper plate  28  of the staple holder  24 . The proximal end of the tensioning tab  32  may be fixed to the upper plate  28  of the staple holder  24 , and the distal end of the tensioning tab  32  may be free and biased downward into the staple holder  24 . A stop tab  34  may be defined in the upper plate  28  of the staple holder  24 . Referring also to  FIGS. 5-7 . the distal end of the stop tab  34  may be fixed to the upper plate  28  of the staple holder  24 , and the proximal end of the stop tab  34  may be free and biased downward into the staple holder  24 . A post  36  may be defined on the lower surface of the stop tab  34  near the proximal end of the stop tab  34 . Alternately, the post  36  may be located at a different position on the stop tab  34 , or may be omitted altogether. 
     Referring also to  FIG. 4 , an actuation assembly  40  also may extend into a space defined within the staple holder  24 . The actuation assembly  40  may include a drive bar  42  that may extend proximally out of the staple holder  24 , or that may be held entirely within the staple holder  24  and also be connected to a control member (not shown) extending into the shaft  26 . The drive bar  42  may be substantially rigid, and may have any suitable shape. An aperture  44  may be defined on an upper surface of the drive bar  42 . The drive bar  42  may include a ramp  43  along its upper surface extending downward in the proximal direction, where the ramp  43  is located proximal to the aperture  44 , and where the ramp  43  connects a higher surface at the distal end of the drive bar  42  to a lower surface of the drive bar  42  proximal to the ramp  43 . 
     Lateral to the drive bar  42 , on one or both sides of the drive bar  42 , the actuation assembly  40  includes at least one wedge  50 . Each wedge  50  is laterally positioned relative to the drive bar to encounter a row  8  of staples  4  during actuation of the drive bar  42 , as described in greater detail below. At least one wedge  50  may be generally parallel to the drive bar  42 . Advantageously, the wedges  50  may be generally parallel to one another. A wedge arm  52  may extend proximally from the wedge  50 , from a lower surface of the wedge  50 . The wedge arm  52  may be generally long and thin. Alternately, the wedge arm  52  may be shaped or configured differently, or may be omitted altogether. The wedge  50  may be shaped substantially as set forth in the Endocutter Documents, or may be shaped in any other suitable manner for engaging and deploying staples  4 . Each wedge  50  may be connected to the drive bar  42  in any suitable manner. As one example, a pin  54  may extend through the drive bar  42  and be received by an aperture in the wedge  50 . The wedge  50  may be freely rotatable about the pin  54 , and/or the pin  54  may be freely rotatable relative to the drive bar  42 . The pin  54  may extend through the drive bar  42  and through or into all of the wedges  50 . Alternately, multiple pins  54  may be used. The ends of the pin  54  may be enlarged in diameter in order to retain the pin  54  within the actuation assembly  40  and prevent it from sliding out of the actuation assembly  40 . The location of the pin  54  relative to the wedge  50  is selected to facilitate bending of the wedge arm  52  and rotation of the wedge  50 , as described in greater detail below. Referring also to  FIG. 5 , the underside of the wedge  50  may include a center notch  70  defined therein. The underside of the wedge  50  may also, or instead, include a proximal notch  72  defined therein. Between the notches  70 ,  72  is a resulting protrusion  74  having a proximal end and a distal end. The wedge  50  and wedge arm  52  may be fabricated from any suitable material, including superelastic material such as nicklel-titanium alloy and plastically deformable material such as stainless steel. 
     Where the feeder belt  2  includes two rows  8  of staples  4 , and two feeder belts  2  are utilized, one feeder belt  2  may be placed in the staple holder  24  on either side of the drive bar  42 . Thus, advantageously two wedges  50  are positioned on either side of the drive bar  42 . Those wedges  50  may be separated by a belt support  56 , such that one belt support  56  is provided on each side of the drive bar  42 . Each belt support  56  has a generally flat upper surface  58  across a portion of its length. The upper surface  58  may be substantially the same width as the feeder belt  2 , or slightly narrower than the feeder belt  2 . The upper surface  58  supports the feeder belt  2  during staple formation, and assists in constraining the vertical motion of the feeder belt  2  during staple formation, as described in greater detail below. The upper surface  58  of each belt support  56  may be angled or curved downward in the proximal direction at its proximal end. The belt supports  56  may be connected to the drive bar via a pin  54 , or in any other suitable manner. 
     Referring also to  FIG. 8 , a cutter  60  may be fixed to the drive bar  42 . The cutter  60  may be flexible, such as described in U.S. patent application Ser. No. 12/435,653, filed on May 5, 2009 (the “Knife Document”), which is hereby incorporated by reference in its entirety. The cutter  60  may include a knife  62  at the distal end of an arm  64 . The arm  64  may be fixed to the drive bar  42  in any suitable manner. As one example, the arm  64  may include two apertures  66  configured to engage two corresponding posts in an inner volume of the drive bar  42 . The posts may be molded into those apertures  66 , or otherwise engage the apertures. The arm  64  may instead be fixed to the drive bar  42  in any other suitable manner. The cutter  60  may be in its neutral state as shown in  FIG. 8 , where the knife  62  and the cutting edge  68  of the knife  62  are located below the upper plate  28  of the staple holder  24 . Alternately, the cutter  60  may not be in the neutral state as shown in  FIG. 8 , and instead may be held in that position in any suitable manner. As described in greater detail below, the knife  62  and cutting edge  68  move upward through the aperture  44  in the drive bar  42  and out of the upper plate  28  of the staple holder  24  to cut tissue during actuation of the staple holder  24 . The pin or pins  54  are configured to ensure that the knife  62  is movable in that manner without engaging the pin or pins  54  and being prevented from moving upward. Alternately, the cutter  60  may be configured in any other suitable manner. 
     Operation 
     Actuation of the feeder belt  2  may be performed as described in the Endocutter Documents, or in any other suitable manner, as modified by the description below. The end effector  20  is introduced into the patient, and is closed onto tissue. The end effector  20  is then actuated to deploy the staples  4  into tissue. The actuation assembly  40  is initially located in an initial position in a distal region of the staple holder  24 . The actuation assembly  40  is pulled proximally in order to deploy staples  4  and cut tissue, to a final position. The actuation assembly  40  is then moved distally back to the initial position before the next firing. 
     Proximal force is applied to the drive bar  42 . As the drive bar  42  moves proximally, it pulls the wedges  50  proximally. As set forth in the Endocutter Documents, each wedge  50  encounters staples  4  in a row  8  one after the other, and drives those staples  4  into tissue, deforms them, and shears them from the feeder belt  2 . The drive bar  42  also pulls the belt supports  56  proximally. The feeder belt  2  corresponding to each belt support  56  is constrained vertically between the upper surface  58  of the belt support  56  and the lower surface of the upper plate  28 , which may be only slightly greater than the thickness of the feeder belt  2 . In this way, lateral twisting, longitudinal bowing and other deformations of the feeder belt  2  during firing of the staples  4  is minimized. Further, any deformation of the feeder belt  2  resulting from its advancement into the staple holder  24  may be smoothed by entry of that feeder belt  2  into the constrained space between the upper surface  58  of the belt support  56  and the lower surface of the upper plate  28 . As the belt support  56  and corresponding wedges  50  slide proximally, the two may remain substantially fixed in position relative to one another, such that the belt support  56  supports the feeder belt  2  longitudinally relative to the wedges in the same manner throughout travel of the actuation assembly. 
     Further, referring to  FIG. 10 , prior to actuation of the actuation assembly  40  and firing of the staples, the tensioning tab  32  is biased downward into the staple holder  24 , as described above. The free end of the tensioning tab  32  is located proximal to, and is adjacent to, a corresponding pull tab  6  of at least one feeder belt  2 . Where two feeder belts  2  are used, the tensioning tab  32  is advantageously wide enough to engage pull tabs  6  of both feeder belts  2 , and those pull tabs  6  are oriented such that the tensioning tab  32  can do so. As the actuation assembly  40  moves proximally and the wedges  50  begin to contact and deform the staples, the wedges  50  exert a force on the feeder belt  2  that has a component in the proximal direction. That proximal force pulls the pull tab  6  located distal to the tensioning tab  32  into contact with the tensioning tab  32 , such that the tensioning tab  32  prevents proximal motion of the pull tab  6  and therefore restrains the feeder belt  2  against proximal motion. In this way, the proximal motion of the wedges  50  causes tensioning of the feeder belt  2 . That tension, and/or the constraint of the feeder belt  2  vertically between the upper surface  58  of the belt support  56  and the lower surface of the upper plate  28 , holds the feeder belt  2  in place during firing of the staples  4 , such that the feeder belt  2  need not be clamped as set forth in the Endocutter Documents. Optionally, the feeder belt  2  also may be clamped, if desired. 
     Referring also to  FIG. 9 , as the actuation assembly  40  moves proximally, the knife  62  of the cutter  60  moves upward through the aperture  44  in the drive bar  42  and upward through a slot  45  in the upper plate  28 . This upward motion of the knife  62  may occur substantially as set forth in the Knife Document, and/or in any other suitable manner. The cutting edge  68  encounters and incises tissue adjacent to the upper plate  28 . As the actuation assembly  40  continues to move proximally, the knife  62  and cutting edge  68  move proximally as well, incising tissue along the upper plate  28  of the staple holder  24 . The knife  62  may be positioned longitudinally in any suitable manner relative to the wedges  50 , such that the knife  62  may cut tissue before, during or after staples  4  are sheared off the feeder belt  2  into adjacent tissue. 
     Referring also to  FIG. 5 , as the actuation assembly  40  nears the end of its travel, the ramp  43  of the drive bar  42  may encounter the post  36  defined on the lower surface of the stop tab  34 . The proximal, free end of the stop tab  34  had previously been located adjacent to a pull tab  6  of at least one feeder belt  2 . The ramp  43  is sized such that the stop tab  34  is moved out of engagement with that pull tab  6 . As the drive bar  42  continues to move proximally, the post  36  continued to ride on the upper surface of the drive bar  42  distal to the ramp  43 , which is shaped and sized to continue to hold the stop tab  34  out of engagement with the pull tab or tabs  6  it had previously engaged. 
     As the actuation assembly  40  continues to move proximally, the protrusion  74  on the bottom surface of each wedge  50  may approach an aperture  78  defined in a lower surface of the staple holder  24 . The aperture  78  may be defined completely through the lower surface of the staple holder  24 , or may be a trough or other volume that does not extend through the surface of the staple holder  24 . Referring also to  FIG. 6 , the actuation assembly  40  moves further proximally. The upper surface of the wedge  50  encounters the pull tab  6  to which the stop tab  34  had previously been adjacent. The pull tab  6  is substantially fixed in position vertically. Thus, this contact between the wedge  50  and the pull tab  6  of the corresponding feeder belt  2  causes the wedge  50  to deflect downward. The wedge  50  rotates slightly about the pin  54 , causing the wedge arm  52  to bow upward. The proximal end of the wedge arm  52  may be fixed to the corresponding belt support  56 , or may be trapped between the belt support  56  and the interior of the staple holder  24  such that the belt support  56  restrains the wedge arm  52  against proximal motion. The protrusion  74  of the wedge  50  is pushed into the aperture  78  as the wedge  50  rotates. The actuation assembly  40  continues to move proximally, and the deflected wedge  50  slides under the pull tab  6 . Where the feeder belt  2  includes two rows  8  of staples  4 , and two wedges  50  are used to fire those staples  4 , each pull tab  6  may extend laterally from both sides of the feeder belt  2 , such that a pull tab  6  is in position for each wedge  50  to encounter and deflect downward. 
     Referring also to  FIG. 7 , as the actuation assembly  40  continues to move proximally, the wedge  50  moves proximal to the pull tab  6 . At that point, the pull tab  6  no longer holds the wedge  50  down, and the wedge  50  is free to move upward behind the pull tab  6  to its original state. The wedge  50  rotates slightly about the pin  54 , and the wedge arm  52  straightens back to its initial state. The protrusion  74  of the wedge  50  also moves upward out of the aperture  78 . The wedge  50  is, at this point, located behind the corresponding pull tab  6 , with the pull tab  6  located lower than the upper surface of the distal end of the wedge  50 . The actuation assembly  40  has at this point reached the end of its travel. 
     The end effector  20  may then be reset. Such resetting may be performed before, during or after the opening of the end effector  20  after its treatment of tissue adjacent to the staple holder  24 . The drive bar  42  is advanced distally. As the drive bar  42  is advanced distally, the distal end of each wedge  50  encounters the corresponding pull tab  6 . That pull tab  6  is proximal to the staples  4  in the row that were deployed and sheared off the feeder belt  2  during the previous actuation. The distal motion of the wedge  50  pushes that corresponding pull tab  6  distally, thereby pushing the feeder belt  2  to which the pull tab  6  is fixed distally as well. Where two wedges  50  are used to deploy staples  4  in rows  8  on both sides of the feeder belt  2 , two wedges  50  each push a side of the pull tab  6  distally, such that the force exerted on the feeder belt  2  is substantially entirely in the distal direction. The wedges  50  continue to push the pull tabs  6  forward, and those pull tabs  6  encounter the tensioning tab  32  in the upper plate  28  of the staple holder  24 . That encounter pushes the tensioning tab  32  upward, and the pull tabs  6  move distal to the free end of the tensioning tab  32 . Referring also to  FIG. 10 , at that point, the tensioning tab  32  moves downward, such that the free end of the tensioning tab  32  is adjacent to and proximal to the pull tabs  6 . The feeder belt  2  is thus in firing position to deploy the next group  10  of staples  4 , and the actuation assembly  40  is in its initial position for the next firing, as is the tensioning tab  32 . The wedges  50  are thereby used not only to deploy staples  4  and separate the staples  4  from the feeder belt  2 , but also to advance the feeder belt  2  afterward in order to prepare for the next deployment. In this way, the number of parts and the complexity of the tool can be minimized. 
     Distal travel of the actuation assembly  40  may be limited by the stop tab  34 . As the drive bar  42  moves distally, the post  36  of the stop tab  34  rides down the ramp  43  on the upper surface of the drive bar  42 , such that the drive bar  42  no longer pushes the stop tab  34  upward out of the way of the pull tabs  6 . Distal motion of the feeder belt  2  as pushed distally by the wedges  50  may be stopped by contact between the next most proximal pull tabs  6  and the free end of the stop tab  34 . Alternately, distal travel of the actuation assembly  40  is affirmatively controlled by the handle or other component of the surgical stapler. The stop tab  32  is thus back in its initial position. 
     The cutter  60  is also reset as the actuation assembly  40  moves distally. The cutting edge  68  of the knife  62  is oriented proximally, such that motion of the knife  62  in the distal direction during resetting does not substantially affect tissue, if tissue is still adjacent to the staple holder  24  during reset. The cutter  60  is fixed to the drive bar  42 , such that distal motion of the drive bar  42  pushes the cutter  60  distally. As the cutter  60  returns toward its initial position, the knife  62  flexes downward back into the staple holder  24  underneath the upper plate  28 , such as set forth in the Knife Document. Alternately, the knife  62  can be returned to its initial position in any suitable manner. 
     The terms “upper,” “lower,” “upward,” “downward,” “up,” “down,” “below,” “above,” “vertical,” and the like are used solely for convenience in this document; such terms refer to directions on the printed page and do not limit the orientation of the surgical stapler in use. While the invention has been described in detail, it will be apparent to one skilled in the art that various changes and modifications can be made and equivalents employed, without departing from the present invention. It is to be understood that the invention is not limited to the details of construction, the arrangements of components, and/or the method set forth in the above description or illustrated in the drawings. Statements in the abstract of this document, and any summary statements in this document, are merely exemplary; they are not, and cannot be interpreted as, limiting the scope of the claims. Further, the figures are merely exemplary and not limiting. Topical headings and subheadings are for the convenience of the reader only. They should not and cannot be construed to have any substantive significance, meaning or interpretation, and should not and cannot be deemed to indicate that all of the information relating to any particular topic is to be found under or limited to any particular heading or subheading. Therefore, the invention is not to be restricted or limited except in accordance with the following claims and their legal equivalents.