Abstract:
A device having a cutting implement movable in a direction generally parallel to a tissue surface and creating a cut line that does not extend to the proximal end of tissue adjacent the device is disclosed. The device has a cutting implement that emerges from a tissue engaging surface and cuts tissue only between a proximal and distal ends of the adjoining staple lines. A method is further provided for anastomosing two lumens without extending the passageway between them to the openings made for the forks of the anastomosis device.

Description:
[0001]    This application is related to the copending U.S. patent application Ser. No.______ [Attorney Docket No. END-868], which is hereby incorporated herein by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates, in general, to devices and methods for surgically performing anastomosis of hollow organs or vessels.  
         BACKGROUND OF THE INVENTION  
         [0003]    Creating an anastomosis, or the surgical formation of a passage between two normally distinct lumens, is a critical step of many surgical procedures. This is true in intestinal cancer in which a portion of the small intestine is removed and the remaining portions are rejoined to form a complete path for the flow of ingesta. An anastomosis of the intestines also occurs in gastric bypass surgery, which is performed to cause weight loss in obese patients. In gastric surgery, a gastric pouch is formed by dissecting the stomach. Repeated applications of a linear cutter are used to separate a small portion of the stomach just distal to the esophagus from the rest of the stomach. The jejunum is then transected distally with a linear cutter, a device that both severs and staples tissue. Thereafter, the distal portion of the jejunum, called the Roux limb, is brought to form an anastomosis with the gastric pouch, often referred to as a gastroenterostomy. The gastroenterostomy can be performed with a linear cutter, circular stapler, or hand sewing. Following the gastroenterostomy, the linear cutter may be used to perform a side to side anastomosis to join the Roux limb to the portion of the jejunum extending below the lower portion of the dissected stomach, often referred to as an enteroenterostomy.  
           [0004]    Typical linear cutters have two forks forming an implement on the distal end. One fork contains a cartridge assembly to eject staples and a cutting implement to sever tissue, while the other fork has an anvil containing pockets to form staples into the correct shape for holding tissue. The cartridge assembly generally has a tissue surface, which abuts the tissue to be cut and stapled when the forks are placed on tissue and closed. An example of an endocutter can be found in U.S. Pat. No. 5,673,840 issued on Oct. 7, 1997, which is hereby incorporated herein by reference.  
           [0005]    When making a side to side anastomosis using a linear cutter, a surgeon aligns two lumens so that the side walls touch. A small opening is made in each lumen to allow entry of a fork of a linear cutter. One fork of the linear cutter is inserted into one lumen, and the other fork of the linear cutter is inserted into the other lumen. The forks of the linear cutter are then closed so that a portion of one wall of each lumen is compressed between them. The two small entry openings are separated only by these two compressed lumen wall portions. Firing the linear cutter severs and staples tissue along a line extending from the proximal end of tissue in the device to a point near the end of the forks, and creates a cutline that extends radially outwards from the original entry openings between the staple lines. A large, irregularly shaped opening to the outside of the lumens is created. The large opening to the outside of the lumens requires closure while maintaining the desired communication between the two lumens. Closing the opening to the outside of the lumens, while leaving recently formed passageway intact, can be a difficult task requiring much surgical skill and operating room time. The surgeon can have difficulty in keeping the lumens uniform while sewing a large opening, as the lumens tend to plicate and become irregular as the needle passes through the opening. A surgeon may prefer to staple the opening by use of a stapling device applied perpendicular to the first application. While the second stapling has worked adequately, difficulty in positioning the second application of the stapling device can make it difficult to ascertain the size of the resultant passageway.  
           [0006]    If the passageway between the two lumens were not to extend proximally into the entry openings made for the members of the linear cutter, only closure of two small entry openings would be required. The lumens would then remain more regular, and the size of the passageway would become more predictable. A linear stapling device creating a cut line that does not extend to the proximal end of the tissue within the working forks is described in U.S. Pat. No. 6,066,144 issued to Wolf et al on May 23, 2000, which is hereby incorporated herein by reference. However, Wolf et al&#39;s cutting blade moves generally perpendicular to the plane of the tissue compressed in the device, much as a cheesewire cutting cheese. This cutting action, useful for delicate vascular tissue, may not be the optimum action to sever tough bowel and stomach tissue. Cutting generally parallel to the tissue plane, and generally parallel to the tissue surface of the cartridge, presents less tissue area to the blade, and so decreases force needed to cut tough tissue.  
           [0007]    Applicants have recognized the need for a cutting device having a tissue surface to abut tissue and a cutting implement movable generally parallel to the plane of the tissue surface to create a cut line that does not extend to the proximal end of the tissue abutting the device. Applicants have recognized the need for a device having a cutting implement that moves parallel to the tissue to be severed, and can be cammed towards and away from the tissue to be severed to locate the cut line relative to the device. Applicants have further recognized a need for a method of using the device to perform an anastomosis.  
         SUMMARY OF THE INVENTION  
         [0008]    There is provided a device having a tissue surface and a cutting implement movable generally parallel to the plane of the tissue surface and capable of producing a cut line that does not extend to the proximal end of tissue abutting the device. The cutting implement can be cammed towards and away from tissue to be severed to control the longitudinal position of the passageway created. The device can further include surgical fasteners, or staples, for holding together the severed edges of the tissue. There is also provided a method of joining two lumens without extending a cut line into two small entry openings made for the forks of a surgical anastomosis instrument.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    The novel features of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to organization and methods of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings in which:  
         [0010]    [0010]FIG. 1 is an isometric view of a surgical cutter having an a cartridge assembly according to an embodiment of the invention.  
         [0011]    [0011]FIG. 2 is an isometric view of a cartridge assembly according to an embodiment of the invention.  
         [0012]    [0012]FIG. 3 is an isometric view with a section taken along line  2 - 2  of FIG. 1.  
         [0013]    [0013]FIG. 4 is an isometric view of a cutting implement used within the cartridge assembly of FIG. 1.  
         [0014]    [0014]FIG. 5 is a section view in side elevation taken along line  2 - 2  of FIG. 1 with the cutting implement at a proximal position within the cartridge assembly.  
         [0015]    [0015]FIG. 6 is a section view in side elevation taken along line  2 - 2  of FIG. 1 with the cutting implement moved distally to the ascending ramp portion of the cartridge assembly.  
         [0016]    [0016]FIG. 7 is a section view in side elevation taken along line  2 - 2  FIG. 1 with the cutting implement moved distally to the central cam portion of the cartridge assembly.  
         [0017]    [0017]FIG. 8 is a section view in side elevation taken along line  2 - 2  of FIG. 1 with the cutting implement moved distally to the descending ramp portion of the cartridge assembly.  
         [0018]    [0018]FIG. 9 is an isometric view showing the cartridge assembly of FIG. 1 used in an endoscopic linear cutter inserted into two lumens to begin a side to side anastomosis.  
         [0019]    [0019]FIG. 10 is an isometric view showing a side to side anastomosis with one lumen partially broken away to show a passageway created by a linear cutter using the cartridge assembly of FIG. 1. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    [0020]FIG. 1 shows an isometric view of a surgical cutter or linear cutter  11  equipped with a cartridge assembly  10  and an anvil  21 . Linear cutter  11  comprises a frame  23  capable of carrying cartridge assembly  10  and using cartridge assembly  10  to create an opening within tissue. Frame  23  of linear cutter  11  also provides a closing trigger  27  and a firing trigger  29 . Closing trigger  27  and firing trigger  29  both rotate proximally to actuate mechanisms to effect tissue approximate cartridge assembly  10  and anvil  21 .  
         [0021]    [0021]FIG. 1 further shows how linear cutter  11  can be constructed to manipulate tissue. Linear cutter  11  possesses a shaft  40  having a shaft proximal end  42  and a shaft distal end  44 . Cartridge assembly  10  and anvil  21  can be described as two linear forks attaching to linear cutter  11  at shaft distal end  44 . Cartridge assembly  10  and anvil  21  together comprise an end effector to perform work on tissue. Cartridge assembly  10  provides a housing tissue surface  16 , or first tissue engaging surface, to contact tissue in use, while anvil  21  provides an anvil tissue surface  48 , or second tissue engaging surface. FIG. 1 depicts cartridge assembly  10  and anvil  21  open to receive tissue, however, anvil  21  may rotate towards cartridge assembly  10  until anvil tissue surface  48  and housing tissue surface  16  are substantially parallel. The two substantially parallel tissue surfaces can establish a longitudinal axis  46  parallel to and between the surfaces.  
         [0022]    [0022]FIG. 2 shows an isometric view of cartridge assembly  10 . Cartridge assembly  10  has a cartridge, or a housing  25 , on which housing tissue surface  16  exists to abut tissue to be cut and stapled using cartridge assembly  10 . Cartridge assembly  10  further contains a plurality of tissue fasteners, or staples  15  residing in staple pockets  13 . Staples  15  are arranged in at least two spaced staple rows  50 . FIG. 2 depicts six staple rows  50 . The staple rows  50  commence at a staple row proximal end  52  and end at a staple row distal end  54 .  
         [0023]    [0023]FIG. 3 shows an isometric section view taken to reveal the cam surfaces  12  of cartridge assembly  10 . The section view further reveals within cartridge assembly  10  a slot  32  and a cutting implement, or knife  18  which can be either part of the cartridge, or within the instrument itself. Cam surfaces  12  extend from the proximal portion of cartridge assembly  10  to a central portion of cartridge assembly  10 . Cam surfaces  12  comprise a cam surface proximal portion  14 , an ascending ramp portion  20 , a central cam portion  24 , and a descending ramp portion  22 . Cam surface proximal portion  14  is separated from tissue surface  16  by a distance large enough so that when knife  18  is in the proximal portion of cartridge assembly  10  it is concealed and not exposed to any tissue adjacent tissue surface  16 . Distal to cam surface proximal portion  14 , an ascending ramp portion  20  extends distally and slopes towards tissue surface  16 . Near the central part of cartridge assembly  10 , ascending ramp portion  20  reaches its closest point to tissue surface  16 . Central cam portion  24  continues distally from ascending ramp portion  20  to descending ramp portion  22 . Near the distal end of cartridge assembly  10 , descending ramp portion  22  slopes distally away from tissue surface  16 . Descending ramp portion  22  begins nearer to tissue surface  16  than central cam portion  24 , and is separated from the rest of cam surfaces  12 . Cam surfaces  12  create a track to direct motion of knife  18  towards and away from tissue surface  16  and any tissue adjacent tissue surface  16 . Cam surfaces  12  can be molded into cartridge assembly  10 .  
         [0024]    [0024]FIG. 3 further shows a cam follower  28  extending from one side of knife  18 . Cam follower  28  contacts and follows cam surfaces  12  as knife  18  advances distally. Knife actuator  26  pushes knife  18  distally. Knife actuator  26  could be, for example, a portion of any endoscopic linear cutter having a frame  23  (FIG. 1) into which cartridge assembly  10  could be inserted, such as a linear cutter  11  depicted in FIG. 1. Knife actuators and other means for actuating the firing and closing of the instrument are well known to those skilled in the art. Examples of such are disclosed in U.S. Pat. No. 5,597,107, issued on Jan. 28, 1997, and which is hereby incorporated herein by reference.  
         [0025]    [0025]FIG. 4 is an isometric view of knife  18 . In addition to cam follower  28 , knife  18  incorporates knife slot  21  to allow knife  18  to flex. The distal end of knife  18  carries a knife edge  33  and a knife tip  30 . Knife edge  33  is capable of slicing tissue, while knife tip  30  can pierce tissue. Knife edge  33  is placed around an angle  34  at the distal end of knife  18 .  
         [0026]    [0026]FIG. 5 shows cartridge assembly  10  with knife  18  placed forward to a point proximal of the intersection of ascending ramp portion  20  and central cam portion  24 . Cartridge assembly  10  can be inserted into linear cutter  11 . Inserting cartridge assembly  10  and pulling firing trigger  29  (FIG. 1) moves knife actuator  26  forward causing knife  18  to move through slot  32 . Cam follower  28  contacts cam surfaces  12  to urge knife  18  towards and away from tissue surface  16  as knife  18  moves distally generally parallel to tissue surface  16 . Cam follower  28  first contacts cam surface proximal portion  14 . While cam follower  28  contacts cam surface proximal portion  14 , knife  18  avoids tissue surface  16  and does not cut tissue. As knife  18  moves distally, cam follower  28  contacts ascending ramp portion  20 , which drives knife  18  towards tissue surface  16 . The distal portion of knife  18  flexes towards tissue surface  16  at the flexible portion or slot  21  while the proximal portion of knife  18  remains in axial alignment with knife actuator  26 . When knife tip  30  is exposed from tissue surface  16 , knife tip  30  pierces tissue adjacent tissue surface  16  and begins making a cut. Because knife edge  33  is placed around angle  34 , the portion of the angled edge nearest the tissue faces and cuts tissue as knife  18  moves towards tissue. Cam follower  28  reaches central cam portion  24  and knife  18  ceases to move towards tissue surface  16 . Knife slot  21  is designed to allow knife  18  to flex to a position shown in FIG. 7. Knife  18  continues to cut tissue abutting tissue surface  16  as knife  18  travels proximally. Knife  18  cuts the tissue in a direction parallel to tissue surface  16 . Knife  18  travels forward parallel to tissue surface  16  until knife  18  reaches descending ramp portion  22 . Descending ramp portion  22  contacts cam follower  28  and drives knife  18  away from tissue surface  16 , placing knife  18  into a position depicted by FIG. 6. Knife  18  moves away from tissue and ceases to cut. Knife  18  is concealed from tissue abutting tissue surface  16 . The mechanism of linear cutter  11  will then cause knife actuator  26  to retract. The configuration of cartridge assembly  10  can cause a cut line that does not extend to the proximal end of the cartridge. The configuration of cartridge assembly  10  causes knife  18  to emerge from housing tissue surface  16  only between staple row proximal end  52  and staple row distal end  54  (FIG. 2). Using cartridge assembly  10  in linear cutter  11  causes linear cutter  11  to produce in tissue abutting tissue surface  16  a cut line that does not extend proximally to the proximal portion of the tissue. Knife  18  cuts only between staple row proximal end  52  and staple row distal end  54 .  
         [0027]    [0027]FIGS. 9 and 10 show a side-to-side anastomosis of two body lumens. In a side-to-side anastomosis of two body lumens, a surgeon can use linear cutter  11  equipped with cartridge assembly  10  and anvil  21 . FIG. 9 shows that the surgeon creates two small openings  17 , one each in each body lumen, and inserts anvil  21  of linear cutter  11  in a first lumen and the cartridge assembly  10  of linear cutter  11  into the second lumen. Closing anvil  21  to cartridge assembly  10  compresses a portion of a wall of each body lumen into a plane adjacent tissue surface  16 . The portions of the edges of the openings clamped between anvil  21  and cartridge assembly  10  become the proximal tissue end  31 . The surgeon then can fire linear cutter  11  creating a cut line and a passageway  36  in the tissue clamped between anvil  21  and cartridge assembly  10  of linear cutter  11  by moving knife  18  generally parallel to tissue surface  16  and the plane of the compressed tissue. Knife  18  begins the cut line at a point distal to proximal tissue end  31 , and cuts only between staple row proximal end  52  and staple row distal end  54 . A portion of tissue distal to staple row proximal end  52  is left uncut. The surgeon need close only two small openings  17  to complete the procedure, creating passageway  36 .  
         [0028]    [0028]FIG. 10 shows the resultant passageway  36  created. Linear cutter  11  has inserted staples  15  into tissue adjacent the cut line to adhere the wall of one lumen to the wall of the other lumen, to control bleeding, and to prevent leakage of lumen contents to the lumen&#39;s exterior. A distance of uncut tissue  35  will exist in the lumen walls between the openings  17  and the proximal end of passageway  36 . Sutures or staples may be used to close the two openings  17 . Matter, such as digestive fluids or ingesta, may pass through passageway  36 . If the anastomosis were a vascular anastomosis, blood may pass through passageway  36 .  
         [0029]    It will be recognized that equivalent structures may be substituted for the structures illustrated and described herein and that the described embodiment of the invention is not the only structure which may be employed to implement the claimed invention. As one example of an equivalent structure that may be used to implement the present invention, linear cutter  11  may be any linear cutter, useful for open or endoscopic surgery, having a frame  23  to which the cartridge assembly  10  may be attached. Linear cutter  11  may further include alternate equipment to adhere tissue, such as radiofrequency energy appliers, or laser energy appliers. As a further example of an equivalent structure, knife  18  may be any cutting implement such as a disk with an edge about its circumference. The disk may be advanced distally, substantially parallel to tissue surface  16 , as it is cammed towards and away from tissue surface  16 . As a further example of an equivalent method that may be used to implement the present invention, the method of joining two lumens can be useful in joining many types of internal body lumens such as the stomach, small bowel, urinary vessels, or blood vessels. Such a method becomes useful in joining small intestine to small intestine, or small intestine to stomach, as is often done in gastric bypass surgery.  
         [0030]    Another method of cutting substantially parallel to a tissue surface can be to rotate a knife so that the cutting edge faces tissue at an area where the proximal end of the cut should begin. The knife, for example, can have a profile such that it lies within a slot in the cartridge below the tissue surface. The profile of the knife is such that the cutting edge is longer, and hence taller to extend above the tissue surface of the cartridge when rotated to cause the cutting edge to face tissue. A pivot point, such as a pin, can be placed within the knife slot where the proximal end of the cut in tissue is desired. A push arm pushes the knife distally, and the pin intercepts the distally moving knife. The knife can then rotate from a profile in which it lies below the surface of the tissue to a second position presenting the cutting edge to tissue. The push arm engages the knife at a point a distance away from the pivot point, or pin. The force exerted by the push arm and the reactive force by the push pin create, because of the separation in distance from the two points, a moment tending to rotate the knife. After rotation, the knife can travel distally while the cutting edge faces tissue, to cut tissue and create anotomy.  
         [0031]    While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. For example, as would be apparent to those skilled in the art, the disclosures herein have equal application in robotic-assisted surgery. In addition, it should be understood that every structure described above has a function and such structure can be referred to as a means for performing that function. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.