Abstract:
A disposable surgical stapler cartridge having a pair of partially engaged staple retaining and unloading members and a plurality of staples for joining together body tissues. Each staple has a center portion and a pair of adjoining downward extending side portions. Lower portions of the side portions are modified in cross-section to provide hinge points which reduce the required force for clinching the staples. The apertures of the cartridge retaining member require higher initial forces for unloading the staples from the member. The cartridge is detachably mounted in a jaw of a stapler by a pair of rails which slidably engage channels of the jaw and a boss which forcibly engages an aperture of the jaw. During a clinching of the staples the cartridge members are fully engaged to reduce the size of the cartridge.

Description:
RELATED U.S. APPLICATION DATA 
     Division of application Ser. No. 09/145,443 filed on Sep. 2, 1998, now U.S. Pat. No. 6,131,790. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to surgical instruments and, more particularly, to an improved stapler and cartridge for joining layers of body tissues. 
     BACKGROUND OF THE INVENTION 
     Since the introduction of surgical staplers, they have enjoyed substantial success with surgeons for a variety of procedures. Staplers have improved many surgical procedures because of their ability to perform uniform tissue-fastening and consistent results with a squeeze of a handle. In meeting the ever-increasing demand for improvements, numerous changes have been made over the years in surgical staplers and cartridges. However, in spite of the substantial success which staplers have enjoyed and the substantial efforts expended in achieving improvements, several areas have remained completely incapable of resolution, until the present invention. 
     U.S. Pat. No. 4,354,628; U.S. 4,566,620; U.S. 5,111,987; and U.S. 5,425,745 are exemplary of currently used staplers which exist in the prior art. One characteristic feature of these staplers is that pusher bars and complex linkages are used to clamp, connect and divide layers of body tissues. Another characteristic feature is that they are disposable. 
     One of the principal drawbacks encountered with current staplers is their high costs. Despite their advantages over needles and thread, staplers have been under-utilized because of their high costs. Much of the high costs is due to complexity and numerous internal parts which are difficult to clean and sterilize. These difficulties have resulted in a practice of disposing staplers after a single use. Costs of disposing staplers has been somewhat offset by the use of plastic materials, however, a substantial cost penalty continues to exist. 
     Another drawback with some current staplers is that actuation of separate levers are required to clamp body tissues and to clinch staples. 
     Another drawback with some current staplers and cartridges is their size which limits their applications. 
     SUMMARY OF THE INVENTION 
     All of the drawbacks and difficulties encountered with current staplers are completely overcome with the present invention. In order to overcome these drawbacks, the present invention provides a reusable stapler which is easily cleaned and sterilized, is adaptable to endoscopic and open wound surgery and is improved in function. 
     In a first aspect of the invention, a pair of jaws are pivotally connected along a common centerline with a pivot axis of a pair of interconnected handles to join layers of body tissue with closely spaced rows of wire staples. The staples are supplied in a disposable cartridge which is detachably mounted in one of the jaws. The cartridge may also include a knife for separating the body tissues between a pair of adjacent rows of staples. 
     One advantage of the first aspect is that the jaws and handles are exposed for cleaning and sterilizing with existing methods and equipment. Another advantage is that a high force with minimum friction is provided for firing and clinching staples. The high force and minimum friction improves a surgeon&#39;s control over operation of the stapler. Another advantage is that the handles are used for clamping body tissues and clinching staples. Still yet another advantage is that complexity is substantially reduced over current staplers. Another feature of the invention is that a detent is provided on the handles&#39; pivot axis for clamping and positioning the stapler prior to clinching the staples. The detent permits a surgeon to clamp and inspect the position of the stapler with respect to body tissues before clinching staples. If the surgeon is satisfied with the position of the staples, a simple squeeze of a handle fires the staples through the tissue and clinches the ends of the staples. 
     The cartridge which itself is believed to be novel consists of a staple retaining member and a staple ejecting member. The two members are initially partially engaged to ensure proper alignment of the staples with a staple ejecting member. One advantage of the cartridge, as will be fully understood in an ensuing detailed description, is that the size of the cartridge is reduced during the clinching of the staples. This assists a surgeon in removing the stapler more easily from surgical fields, including endoscopic surgery. An optional feature of the cartridge is that pre-formed hinge points are provided to reduce the required force for clinching the staples. This permits the stapler to be reduced. 
     In a second aspect of the invention, a pair of pivotally connected members serve as handles and jaws for clamping layers of body tissue and clinching parallel arranged rows of staples. The staples are provided in a disposable cartridge heretofore described. 
     In a third aspect of the invention, a pair of handles are connected to a pair of pivotally connected jaws by a pair of short links and a long slender rod. 
     In employing the teaching of the present invention, a plurality of additional alternate constructions can be developed to achieve the desired features of the current invention. The embodiments herein described are intended as examples and should not be considered as limiting the scope of the present invention. 
     Further benefits and features of the invention will become apparent from the ensuing detailed description and drawings which disclose the invention. The property in which exclusive rights are claimed is set forth in each of the numbered claims at the conclusion of the detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be better understood and further objects, characterizing features, details and advantages thereof will appear more clearly with reference to the diagrammatic drawings illustrating specific embodiments of the invention by way of non-limiting example only. 
     FIG. 1 is a front view of a first embodiment of a stapler and cartridge having a pair of jaws in open relationship according to the present invention. 
     FIG. 2 is a front view of the stapler and cartridge with the pair of jaws in closed relationship. 
     FIG. 3 is a bottom view of FIG.  2 . 
     FIG. 4 is an end view of FIG.  2 . 
     FIG. 5 is an enlarged cross-sectional view taken on the line  5 — 5  in FIG. 2 showing a resilient means for regulating the relative positions of the stapler&#39;s handles. 
     FIG. 6 is an enlarged cross-sectional view taken on the line  6 — 6  in FIG. 2 showing the condition of the cartridge during a clamping of two layers of body tissue prior to a clinching of the staples. 
     FIG. 7 is an enlarged cross-sectional view taken in a similar manner to FIG. 6 showing the condition of the cartridge after the staples have fired through the two layers of body tissue and clinched. 
     FIG. 8 is an enlarged cross-sectional view taken on the line  8 — 8  in FIG. 2 showing the manner of locating the staples and knife in the cartridge. 
     FIG. 9 is an enlarged cross-sectional view taken on the line  9 — 9  in FIG.  6 . 
     FIG. 10 is an enlarged cross-sectional view taken on the line  10 — 10  in FIG.  7 . 
     FIG. 11 is an enlarged bottom view of the cartridge. 
     FIG. 12 is an enlarged left side view of the cartridge. 
     FIG. 13 is an enlarged plan view of the cartridge. 
     FIG. 14 is an enlarged end view of the cartridge. 
     FIG. 15 is an enlarged partial view of FIG. 11 showing one of the staples. 
     FIG. 16 is an enlarged cross-sectional view taken on the line  16 — 16  in FIG.  15 . 
     FIG. 17 is a front view of an alternate embodiment having elongated jaws. 
     FIG. 18 is a bottom view of the alternate embodiment. 
     FIG. 19 is a front view of the alternate embodiment showing the jaws in an open condition. 
     FIG. 20 is an enlarged cross-sectional view taken on the line  20 — 20  in FIG.  17 . 
     FIG. 21 is an enlarged cross-sectional view taken on the line  21 — 21  in FIG. 17 showing the condition of the cartridge after the staples have fired through two layers of body tissue and clinched. 
     FIG. 22 is an enlarged cross-sectional view taken on the line  22 — 22  in FIG.  17 . 
     FIG. 23 is a front view of a third embodiment showing a pair of jaws in an open position. 
     FIG. 24 is a front view of the second embodiment showing the pair of jaws in a closed position. 
     FIG. 25 is a bottom view of the second embodiment. 
     FIG. 26 is a fragmentary plan view of a fourth embodiment. 
     FIG. 27 is a fragmentary front view of the fourth embodiment. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings wherein like numerals designate like and corresponding parts throughout the several views, a first embodiment  30  of a surgical stapler  31  and cartridge  36 , according to the invention is illustrated in FIGS. 1 through 16, inclusive. Since numerous alterations or modifications can be made in the first embodiment and other embodiments detailed herein, without departing from the scope of this invention, the following detailed disclosure, and the remaining embodiments shown and discussed, are intended as examples for achieving the present invention and are not intended, in any way, to limit the scope of the present invention. 
     In the orientations of the drawings, the stapler  31  is comprised of an upper handle  33  pivotally connected to a lower handle  32 . each having an end point  33 A,  32 A pivotally connected to an end point of a pair of pivotally connected jaws  34 ,  35 . A disposable cartridge  36  is detachably mounted in the upper jaw  34 . The lower jaw  35  serves as an anvil and cooperates with the upper jaw  34  and cartridge  36  to clamp layers of body tissue  38  and connect the tissue with rows of staples  39 . 
     With reference to FIGS. 1 and 2, it will be observed that the pivot axis  40  of the handles  32 ,  33  and the pivot axis  41  of the jaws  34 ,  35  lie between the end points of the handles  32 ,  33  and jaws  34 ,  35 . It will be further observed that when the handles  32 ,  33  are brought together the jaws  34 ,  35  close and that when the handles  32 ,  33  are separated the jaws  34 ,  35  open. 
     The stapler  31  has several important advantages over existing staplers. One advantage is reduced cost resulting from reduced complexity. Another advantage is that it can be easily cleaned and sterilized with existing methods and equipment. The difficulty in cleaning and sterilizing is about the same as cleaning and sterilizing surgical forceps in autoclaves of surgical facilities. 
     Another advantage is that when the handles  32 ,  33  are squeezed together a high force is produced for firing the staples  39  through the layers of body tissue  38  and clinching the end portions of the staples  39 . This permits the stapler  31  to be offered in small sizes for procedures such as endoscopic surgery as well as in large sizes for procedures such as open surgery. Referring to FIG. 2, the magnitude of the force can be adjusted by varying the ratio of the distances “A” and “B” between the pivot axes  40 ,  41  of the handles  32 ,  33  and jaws  34 ,  35  and their inner end portions. 
     With reference to FIGS. 2 and 5, a detent  42  on the pivot axis  40  of the handles  32 ,  33  selectively regulates the relative positions of the handles  32 ,  33 . The detent  42  allows the handles  32 ,  33  to be easily moved in increments together and apart during the clamping of the tissues  38  without firing the staples  39 . The detent  42  is comprised of a thin resilient disk  43  which is centered on the pivot axis  40  of the handles  32 ,  33  and a post  44  which is fixed to the lower handle  33 . The resilient disk  43  is keyed to the upper handle by engaging a tab  45  in an aperture  46  and rotates with the upper handle  33 . During the rotation of the handles  32 ,  33 , a plurality of radial depressions  47  of the disk  43  come into contact with a spherical head  48  of the post  44 . The spacing and depth of the radial depressions can optionally be varied to require a higher force to fire the staples than the force to clamp the tissues. The teeth are formed in the disk by coining cutting or another suitable means. The resilient disk  43  is retained in the stapler  31  by the bolt  49  which pivotally connects the handles  32 ,  33 . 
     The preferred construction of the cartridge  36  is best understood by reference to FIGS. 6 through 10 and  11  through  16 , inclusive. In the orientation of the drawings, the cartridge consists of an upper generally rectangular shaped staple unloading member  50  and a generally rectangular shaped staple retaining member  51 . The staple unloading member  50  has a thin upper wall  52 , an adjoining thin outer wall  53  and rows of pusher blades  54  inside of the outer wall  53  which extend downwardly from the upper wall  52 . 
     When the handles  32 ,  33  are squeezed together, the blades  54  push against the staples  39  to eject and fire the staples  39  through the layers of tissue  38  and clinch end portions of the staples  39 . Extending along the sides of the unloading member&#39;s outer wall  53  are narrow rails  55 . The rails  55  engage channels  56  of the stapler upper jaw  34  to support the cartridge  36  in the upper jaw  34 . With reference to FIGS. 2 and 3, on the upper wall  52  of the unloading member  50  is a spherical boss  57 . The height of the boss  57  permits the boss  57  to forcibly engage or disengage an aperture  58  of the upper jaw  34  when the rails  55  are engaged or disengaged with channels  56 . The rails  55  and spherical boss  57  retain the cartridge  36  in the upper jaw  34 . Mounted in the center of the unloading member  50  is a sharp knife  59  for separating the tissues  38  between inner rows of staples  39  during the clinching of the staples  39 . 
     With reference to FIGS. 6 through 8, the staple retaining member  51  is pre-assembled to the staple unloading member  50  by partially engaging the lower portion of the unloading member  50  with an upper portion of the retaining member  51 . During a firing and clinching of the staples  39 , the overall size of the cartridge  36  is reduced as the staple unloading member  50  fully engages the staple retaining member  51 . The reduction in cartridge size facilitates a withdrawal of the cartridge  36  during surgery. 
     Referring to FIG. 15, prior to firing, the staples  39  are individually stored in the retaining member  51  in slotted openings  60 . The center portions  61  of the slotted openings  60  are preferably enlarged to reduce friction and the difficulty in manufacturing the cartridge  36 . With reference to FIG. 16, the upper portions “C” of the slotted openings  60  wherein the staple ejecting member  51  is pre-assembled, are preferably slightly enlarged over the lower portions “D” of the slotted openings  60  which engage the end portions of the staples  39 , to require a higher force to fire the staples  39  than the force for pre-assembling the members  50 ,  51 . A higher force is desirable to deter surgeons from firing the staples  39  before the cartridge  36  is properly positioned. 
     The designs of the staples  39  and their slotted openings  60  is shown in FIGS. 15 and 16. Several features reduce the force requirements for firing and clinching the staples  39 . Lower forces allow the stapler and cartridge to be reduced in size. One optional feature consists of pre-forming hinge points  62  at the lower end portions of the staples  39 . Another feature consists of sharp end portions of the staples. Staples  36  of adjacent rows are preferably staggered as shown in FIG.  11 . Although four rows of staples  39  and a knife  59  shown, it will be apparent that fewer or greater numbers of rows can be provided, with or without the knife. 
     Referring now to FIGS. 18 through 22, inclusive, an embodiment  64  is shown with elongated jaws  65 ,  66  and a reduced size cartridge  67  for endoscopic surgery. As shown in FIGS. 20 and 21 the cartridge  67  has been reduced in size by eliminating the knife  59  and providing only two or three rows of staples  39 . 
     In FIGS. 23 through 25, an embodiment  68  is shown for open surgery. The stapler  69  resembles a pair of standard forceps wherein end portions of pivotally connected upper  70  and lower  71  handles form upper  72  and lower  73  jaws. It will be observed in this embodiment  60  that when the handles  70 ,  71  are brought together the jaws  72 ,  73  open and when the handles  70 ,  71  are separated the jaws  72 ,  73  close. As shown in FIG. 24, the cartridge  36  is preferably parallel to the lower jaw  73  at the point of firing and clinching the staples whereas in the usual forceps, the upper jaw is parallel to the lower jaw when the jaws are closed. 
     In FIGS. 26 and 27 an embodiment  74  is shown for endoscopic surgery. A rod  75 , housed in a tube  76 , opens and closes a pair of jaws  77 ,  78 . One end of the tube  76  is attached to a housing  79  with a threaded nut  80  to allow the tube  76  to be detached during a cleaning and sterilizing of the stapler  81 . 
     One end of the rod  75  is connected by a pin  82  to a pair of slotted links  83 . Opposite ends of the links  83  are pivotally connected to upper  77  and lower  78  jaws and open and close the jaws  77 ,  78  when the links  83  are moved by the rod  75 . The opposite end of the rod  75  is pivotally connected to a movable handle  86  by a pivot bolt  87  and nut  88  which attach the handle  86  in the housing  79 . 
     One portion of the housing  79  extends downwardly to form a fixed handle  89 . A removable cover  90 , attached by the bolt  87  and nut  88  spans an access opening  91  and allows the rod  75  to be removed from the stapler  81  for cleaning and sterilizing. Thus, the stapler  81  can be easily disassembled for cleaning and sterilizing. 
     A detent is provided for selectively positioning the movable handle. The detent  92 , comprised of a thin resilient disk  93  which rotates with the handle  86  and post  94  which is fixed to the housing  79  selectively positions the handle  86 . 
     Referring again to FIGS. 1 through 16, inclusive, in the typical use of the present invention, the cartridge  36  is installed by advancing the rails  55  in the channels  56  and forcibly engaging the spherical boss  57  with the aperture  58 . The jaws  34 ,  35  are opened as shown in FIG. 1, and the layers of tissue  38  to be joined are positioned between the jaws  34 ,  35 . The handles  32 ,  33  are squeezed by an amount which is sufficient to apply a light clamping pressure to the layers of tissues  38  as shown in FIGS. 6 and 9. During the clamping of the tissues  38 , a clicking effect is produced by the detent  42  when the handles  32 ,  33  are moved apart as well as together. The clicking effect enables a surgeon to judge the travel of the handles  32 ,  33  before firing the staples  39 . By counting the clicks during the opening and closing of the handles  32 ,  33 , the surgeon can avoid a premature firing of the staples  39 . 
     After the tissues  38  have been clamped, the position of the jaws  34 ,  35  relative to the tissues  38  is inspected. If the surgeon is not satisfied, the jaws  34 ,  35  are opened, repositioned, and closed. When the surgeon is satisfied that the stapler is properly positioned, the handles  32 ,  33  are tightly squeezed to fire and clinch the staples  39  in the manner shown in FIGS. 7 and 10. 
     During the clinching of the staples  39 , their pointed end portions  63  contact depressions  95  in the lower jaw  35  which bias the pointed end portions  63  of the staples  39  inwardly. After the clinching of the staples  39  the jaws  34 ,  35  are opened, the stapler  31  is removed and the spent cartridge  36  is withdrawn from the stapler  31  and discarded. 
     In the foregoing detailed disclosure of the invention, the construction of the surgical stapler and cartridge and the method of using them have been fully detailed. In addition, alternate embodiments and constructions have been discussed as a part of this detailed disclosure. 
     It will be appreciated that other embodiments can be developed by changes in shape, material, arrangement of parts, and substitution of parts without departing from the spirit thereof.