Abstract:
A method for performing trans-anal resection is achieved by applying a first stitch about the rectum, wherein deep bites of the first stitch capture and fold a rectum wall, creating a longitudinal staple line in the rectal wall at a position adjacent the first stitch, positioning a curved surgical stapler instrument in the rectum for capturing the rectal wall held by the first stitch, firing the surgical stapler instrument creating a circumferential first staple line approximately along the arc defined by the first stitch, and repeating the procedure about the circumference of the rectum until a predetermined portion of the rectum is fully resected.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a surgical stapling and cutting instrument adapted for use in trans-anal resection and an associated method for performing trans-anal resection. More particularly, the present invention relates to a surgical stapling and cutting instrument having a curvature particularly adapted to fit within the rectum adjacent the anal canal for the performance of the trans-anal resection as well as the method for using the surgical stapling and cutting instrument. 
     2. Description of the Prior Art 
     Surgical stapling and cutting instruments are commonly utilized in the diagnosis and treatment of pathologies treated by staple resection. Surgical stapling instruments provide a mechanism to extend the transluminal exploitation of mechanical suturing devices introduced via the anal canal, mouth, stomach and service accesses. Although surgical stapling and cutting instruments are most commonly utilized with rectal pathologies, surgical stapling and cutting instruments may be used in a variety of environments. 
     Surgical stapling and cutting instruments generally include a support frame, an anvil attached to the support frame and a cartridge module carrying a plurality of staples. The instruments also include a driver within the cartridge module which pushes all of the staples out simultaneously into the anvil to form the staples into a generally B-shape, suturing tissue together. In addition, these instruments include approximation mechanisms for moving the cartridge module from a spaced position relative to the anvil to accept tissue therebetween to a closed position where the tissue is clamped between the anvil and the cartridge module. Finally, the instruments include a firing means for moving the staple driver forward to form the staples against the anvil. 
     In addition to other procedures, surgical stapling and cutting instruments have been utilized in conjunction with trans-anal resections. Trans-anal resection is a surgical procedure utilized to remove tissue, for example, tumorous tissue, within the rectum by operating through the anus. This procedure is commonly performed to treat early stage rectal cancer or rectal tumors close to the anus. In accordance with this procedure, a section of the rectum is removed and the remaining opposed edges are coupled to complete the linking of the anus with the remainder of the rectum. 
     With the foregoing in mind, those skilled in the art will appreciate the need for more advanced procedures relating to trans-anal resection, as well as the need for advanced instruments specifically designed to facilitate the advanced surgical procedures. The present invention addresses this need through the provision of a technique for trans-anal resection and an associated curved cutter stapler adapted for assisting in the performance of the procedure. 
     SUMMARY OF THE INVENTION 
     It is, therefore, an object of the present invention to provide a method for performing trans-anal resection. The method is achieved by applying a first stitch about the rectum, wherein deep bites of the first stitch capture and fold a rectum wall, creating a longitudinal staple line in the rectal wall at a position adjacent the first stitch, positioning a curved surgical stapler instrument in the rectum for capturing the rectal wall held by the first stitch, firing the surgical stapler instrument creating a circumferential first staple line approximately along the arc defined by the first stitch, and repeating the procedure about the circumference of the rectum until a predetermined portion of the rectum is fully resected. 
     It is also an object of the present invention to provide a method wherein the first stitch is a whip stitch. 
     It is another object of the present invention to provide a method wherein the first stitch is applied from a one o&#39;clock position to a ten o&#39;clock position. 
     It is a further object of the present invention to provide a method wherein the first stitch is complemented by the application of a traction suture positioned beneath the first stitch to maintain tension on the tissue as the procedure is performed. 
     It is also another object of the present invention to provide a method wherein the longitudinal staple line is applied between the first stitch and the traction suture. 
     It is still another object of the present invention to provide a method including the step of applying a suture at the meeting point of adjacent staple lines. 
     It is yet a further object of the present invention to provide a method wherein the suture is a figure eight suture. 
     It is also an object of the present invention to provide a method wherein the surgical stapler instrument includes a frame having a proximal end and a distal end, with a handle positioned at the proximal end and an end effector positioned at the distal end. The end effector is shaped and dimensioned for supporting a cartridge module. A firing mechanism is associated with the end effector and the cartridge module for selective actuation. The end effector has a radius of curvature optimized for trans-anal resection such that the end effector has a curvature of at most about 40 mm diameter. 
     It is another object of the present invention to provide a method wherein the end effector has a curvature of between approximately a 20 mm diameter and approximately a 40 mm diameter. 
     It is a further object of the present invention to provide a method wherein the end effector has curvature adapted to fit within an envelope having a diameter of approximately 40 mm. 
     Other objects and advantages of the present invention will become apparent from the following detailed description when viewed in conjunction with the accompanying drawings, which set forth certain embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the surgical stapler in accordance with the present invention. 
         FIG. 2  is perspective view of the surgical stapler with the cartridge module removed. 
         FIG. 3  is a perspective view of the surgical stapler with the cartridge housing moved to an intermediate position. 
         FIG. 4  is a perspective view of the surgical stapler with the cartridge housing moved to a closed position. 
         FIG. 5  is a perspective view of the surgical stapler with the firing trigger in a firing position. 
         FIG. 6  is a front perspective view of the cartridge module with the retainer secured thereto. 
         FIG. 7  is a front perspective view of the cartridge module with the retainer removed. 
         FIGS. 8 to 16  disclose the various steps in performing a trans-anal resection in accordance with the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The detailed embodiments of the present invention are disclosed herein. It should be understood, however, that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, the details disclosed herein are not to be interpreted as limiting, but merely as the basis for teaching one skilled in the art how to make and/or use the invention. 
     Referring to  FIG. 1  in combination with  FIGS. 2 to 5 , there is shown a surgical stapling and cutting instrument, in particular, a linear surgical stapler  20  which is designed to staple and cut tissue. The linear surgical stapler  20  has a handle  21  at a first proximal end and an end effector  80  at an opposite distal end. The end effector  80  is curved in accordance with a preferred embodiment of the present invention. Right and left hand structural plates (often called “handle plates”)  34 ,  35 , respectively, connect the handle  21  to the end effector  80  of the instrument (the left hand handle plate  35  is removed and not shown in  FIG. 1 ). The handle  21  has a right hand shroud  22  coupled to a left hand shroud (the left hand shroud is not shown in  FIG. 1 ). The handle  21  also has a body portion  23  to grip and maneuver the linear surgical stapler  20  (see  FIGS. 2 to 5 ). 
     The linear surgical stapler  20  in accordance with the present invention is particularly adapted for use in the performance of trans-anal resection. In particular, access to, and the performance of procedures adjacent to, the anus are made difficult by the limited size of the anus and rectum. The present surgical stapler  20  is specifically shaped and dimensioned for access through the anus and alignment within the rectum during trans-anal resection. In particular, the end effector  80  of the linear surgical stapler  20  is adapted to fit and function within a circular envelope having a diameter of at most 40 mm. With this in mind, and in accordance with a preferred embodiment of the present invention, the linear surgical stapler  20  has a distal end with a tissue end effector  80  having a curvature between a diameter of approximately 20 mm to approximately 40 mm, and more preferably, approximately 36 mm, in order to fit into a minimum oval envelope permitting passage through the anus and performance of a rectal resection procedure. In accordance with a preferred embodiment, an effector having a curvature with a diameter of approximately 36 mm would be structured such that it defines an arc length of approximately 30 mm. 
     The end effector  80  is a surgical fastening assembly that includes a cartridge module  120  (see  FIGS. 6 and 7 ) and a C-shaped supporting structure  81 . The term C-shaped is used throughout the specification to describe the concave nature of the supporting structure  81  and the cartridge module  120 . The C-shaped construction facilitates enhanced functionality and the use of the term “C-shaped” in the present specification should be construed to include a variety of concave shapes which would similarly enhance the functionality of surgical stapling and cutting instruments. The distal end  30  of a closure member  28  is disposed to receive the cartridge module  120 . The end effector  80  also includes a safety lockout mechanism (not shown) for preventing the firing of a previously fired cartridge module  120 . The cartridge module  120  contains a cartridge housing  121  coupled to an anvil  122 . The cartridge module  120  also includes a retaining pin  125 , a knife  126 , a removable retainer  160 , a tissue contacting surface  127  which displays a plurality of staple-containing slots  128  in staggered formation in one or more rows (that is, staple lines) on either side of the knife  126 . Staples (not shown) are fired from the cartridge housing  121  against the staple-forming surface  129  of the anvil  122  that faces the tissue-contacting surface  127  of the cartridge housing  121 . 
     As will become apparent based upon the following disclosure, the present linear surgical stapler  20  is designed as a multiple firing device with a replaceable cartridge module  120 . However, it should be understood that many of the underlying concepts of the present invention may be equally applied in single firing devices without departing from the spirit of the present invention. While the present end effector  80  is disclosed below as being adapted for use in conjunction with a replaceable cartridge module  120  having various components, the concepts underlying the present invention could be applied to a variety of end effectors and cartridge module constructions without departing from the spirit of the present invention. 
     The supporting structure  81  of the end effector  80  is respectively attached to the right and left handle plates  34 ,  35 , by a shoulder rivet  82  and posts  83  which extend from the supporting structure  81  into receiving holes in the handle plates  34 ,  35 . In accordance with a preferred embodiment of the present invention, the supporting structure  81  is formed via a single piece construction. More specifically, the supporting structure  81  is formed by extrusion, for example, of aluminum, with subsequent machining to create the supporting structure  81  disclosed in accordance with the present invention. By constructing the supporting structure  81  in this manner, multiple parts are not required and the associated cost of manufacture and assembly is substantially reduced. In addition, it is believed the unitary structure of the supporting structure  81  enhances the overall stability of the present linear surgical stapler  20 . In addition, the unitary extruded structure of the supporting structure  81  provides for a reduction in weight, easier sterilization since cobalt irradiation will effectively penetrate the extruded aluminum and less trauma to tissue based upon the smooth outer surface achieved via extrusion. 
     The handle  21  of the linear surgical stapler  20  includes a hand grip  24  which the surgeon grasps with the palm of his hand (see  FIGS. 2 to 5 ). The hand grip  24  is composed of a right hand shroud handle  25  (see  FIG. 1 ) and a left hand shroud handle (the left hand shroud handle is not shown in  FIG. 1 ). Pivotally extending from the underside of the handle  21  are a closure trigger  26  and a firing trigger  27 . The linear surgical stapler  20  illustrated in  FIG. 1  is shown with the closure and firing triggers  26 ,  27  in their unactuated positions and with a cartridge module  120  inserted and the retainer  160  removed. Consequently, the cartridge housing  121  is spaced from the anvil  122  for the placement of tissue between the cartridge housing  121  and the anvil  122 . 
     The handle  21  of the linear surgical stapler  20  contains a tissue retaining pin actuation mechanism  100 . The tissue retaining pin actuation mechanism  100  includes a saddle shaped slide  101  positioned on the top surface of the handle  21 . Manual movement of the slide  101  results in distal movement of the push rod  102 . The push rod  102  is coupled to the retaining pin  125  of the cartridge module  120 . The distal movement or proximal retraction of the push rod  102  results in corresponding movement of the retaining pin  125 . The retaining pin actuation mechanism  100  is also releasably coupled to the closure trigger  26  within the handle  21  such that actuation of the closure trigger  26  will result in automatic distal movement of the retaining pin  125  if it has not already been manually moved to its most proximal position. 
     Referring briefly to  FIGS. 2 to 5 , there is illustrated what happens when the cartridge module  120  is loaded and the closure and firing triggers  26 ,  27  are sequentially squeezed toward the hand grip  24  to actuate the end effector  80  of the linear surgical stapler  20 . The linear surgical stapler  20  is loaded with the cartridge module  120 , as shown in  FIG. 2 , and the retainer  160  is removed. The linear surgical stapler  20  is now ready to receive tissue as shown in  FIG. 1 . 
     When the closure trigger  26  is partially squeezed to rest in its first detent position shown in  FIG. 3 , the cartridge housing  121  moves from its fully opened position to an intermediate position between the open and closed positions as discussed below in greater detail. Simultaneously, the tissue retaining pin actuation mechanism  100  moves the retaining pin  125  forward from the cartridge housing  121  through an opening in the anvil  122 . In this position, tissue which has been placed between the cartridge housing  121  and the anvil  122  can be properly positioned, and the retention of the tissue between the cartridge housing  121  and the anvil  122  is assured. Therefore, when the closure trigger  26  has been actuated to its intermediate position, the cartridge housing  121  and anvil  122  are correspondingly positioned in their tissue retaining positions. 
     When the closure trigger  26  is fully squeezed so that it is adjacent the forward end of the hand grip  24 , as illustrated in  FIG. 4 , the tissue contacting surface  127  of the cartridge housing  121  and the staple-forming surface  129  of the anvil  122  are adjacent to each other, and the properly positioned and retained tissue is consequently fully clamped. Additionally, the firing trigger  27  has rotated counterclockwise toward the handgrip  24  to enable the surgeon to grasp the firing trigger  27  for the firing of staples. Accordingly, the firing trigger  27  is now in position for the surgeon to squeeze it to staple and cut the tissue. When the firing trigger  27  has been fully squeezed to fire the staples, as shown in  FIG. 5 , the firing trigger  27  rests in near proximity to the closure trigger  26 . 
     The present linear surgical stapler is constructed in a manner similar to commonly owned and copending applications. As such, further details regarding the structure and operation of the linear surgical stapler  20  may be found in commonly owned U.S. patent application Ser. No. 11/014,910, filed Dec. 20, 2004, entitled “CURVED CUTTER STAPLER SHAPED FOR MALE PELVIS”, which is incorporated herein by reference. 
     In practice, and referring to  FIGS. 8 and 9 , the curved cutter stapler  20  is used in conjunction with a dilator  224  and a spreader  226  in the performance of trans-anal resection in the following manner. Once the portion of the rectum  200  requiring resection is identified, the area is prepared in a conventional manner. In particular, and referring to  FIG. 10 , a dilator  224  is inserted and secured via a plurality of sutures  201  within the rectum. As mentioned above, the preferred envelope in which the end effector  80  must work has a diameter of approximately less than 40 mm. This is because a dilator  224  having a diameter of approximately 40 mm is preferably used in conjunction with the present procedure. Although a dilator having a diameter of approximately 40 mm is used in accordance with the present invention as this is believed to be the largest size dilator which can be used with most patients, those skilled in the art will appreciate that some patients will not accommodate a dilator of 40 mm and, therefore, dilators ranging in size from approximately 30 mm to approximately 40 mm are contemplated for use in accordance with the present invention. Similarly, a spreader  226  with a curvature slightly smaller than that of the dilator  224  may be used in conjunction with the present invention. 
     Thereafter, and with reference to  FIGS. 11 to 16 , a first whip stitch  202  is secured about the rectum  200  from a one o&#39;clock position to an eleven o&#39;clock position. The deep bites of the whip stitch  202  capture and fold the rectum wall  204  in a desired manner. In addition to the placement of a whip stitch  202  as discussed above, a traction suture  206  is positioned beneath the whip stitch  202  and is used to maintain tension on the tissue as the procedure is performed. Thereafter, a traditional linear surgical stapling instrument well known to those skilled in the art is positioned between the whip stitch  202  and the traction suture  206  to create a longitudinal staple line  208  in the rectal wall  204  at a position approximately at one o&#39;clock. Thereafter, the present instrument  20  is placed in the rectal canal  200  and is positioned for capturing the rectal wall  204  held by the first whip stitch  202  positioned between one o&#39;clock and ten o&#39;clock. The instrument  20  is fired and a circumferential first staple line  210  extending from one o&#39;clock to ten o&#39;clock is created. Once this portion of the resection is completed, a second whip stitch  203  is placed from ten o&#39;clock to seven o&#39;clock to capture the rectal wall  204 . The instrument  20  is then once again placed in the rectal canal  200  to capture the rectal wall  204  held by the second whip stitch  203  from ten o&#39;clock to seven o&#39;clock and the instrument  20  is fired creating a staple line  212  thereacross. In accordance with a preferred embodiment of the present invention, a figure eight suture  211  is then placed at the junction of the first and second staple lines  210 ,  212 . Thereafter, a third whip stitch  205  is placed from seven o&#39;clock to four o&#39;clock and the instrument  20  is positioned and fired once again creating a third staple line  214  extending from seven o&#39;clock to four o&#39;clock. As with the prior step, a figure eight suture  213  is placed at the junction of the second and third staple lines  212 ,  214 . Finally, the steps are repeated until the complete rectal section is fully stapled and resected adding a fourth staple line  218  and a figure eight suture  215 . 
     While the preferred embodiments have been shown and described, it will be understood that there is no intent to limit the invention by such disclosure, but rather, is intended to cover all modifications and alternate constructions falling within the spirit and scope of the invention.