Abstract:
A method and apparatus for attaching an instrument to an organ utilizes a plurality of protrusions at the end of an overtube for mechanically engaging the end of an overtube to an organ wall. The apparatus, which is particularly suitable for transluminal surgery through a wall of the digestive tract to access the peritoneal cavity, secures the end of an overtube to the organ wall, such as the stomach or colon, to isolate a portion of the organ wall through which an incision for access to the peritoneal cavity is made.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to surgery, and more particularly to endoscopic surgery. The invention will be specifically disclosed in a connection with an apparatus for use in transluminal endoscopic surgery, but the methods of the invention and devices constructed in accordance with the principles of the invention can be used in a wider variety of applications. 
       BACKGROUND 
       [0002]    In recent years, substantial advancements have occurred in abdominal surgery by accessing organs located in the peritoneal cavity through the digestive tract. An endoscope is passed through a natural orifice of the body, such as the mouth or anus, and the endoscope is extended into a selected area of the digestive tract, such as the stomach or colon, that is proximally located relative to the abdominal structure of interest. A luminal incision is then made in wall of the stomach or colon, and an endoscope is then passed through the luminal incision to perform diagnostic or therapeutic interventions on a structure of interest located in the peritoneal cavity. 
         [0003]    One potential problem with accessing the peritoneal cavity through the digestive system is the possibility of carrying contaminants from the digestive tract into the peritoneal cavity on the instruments that are inserted through the luminal incision of the wall of the colon or stomach. It is, of course, highly desirable to avoid contamination of the peritoneal cavity, and to perform the diagnostic or therapeutic procedure in a sterile field. One method of reducing the risk of contamination is to use an overtube, that is, a tubular member positioned on the outside of the endoscope through which the endoscope may be is slidably movable. An open end of the overtube is secured to wall of the stomach or colon, and a luminal incision is performed inside the area defined by the overtube. The walls of the overtube then function to isolate the area in which the luminal incision is made from the remainder of the digestive tract. With the end of the overtube secured to the wall of the digestive tract, an endoscope is then extended through the end of the overtube and into the peritoneal cavity through the luminal insertion. With the endoscope inserted into the peritoneal cavity, operational instruments are then passed through a working channel in the endoscope to access to an organ of interest located in the peritoneal cavity upon which a diagnostic or therapeutic intervention is desired. 
         [0004]    One way of securing the end of the overtube to the wall of the stomach or colon is through the use of a vacuum. Unfortunately, securing the end of an overtube to the wall of a stomach or colon with a vacuum is not always fully reliable. The stomach wall, for example, is very flexible, and the seal between the end of the overtube and the stomach wall is easily lost whenever the stomach flexes or otherwise moves. When the seal between the end of the overtube and the stomach wall is lost, the luminal incision is no longer isolated from the remaining areas of the digestive track, and the passage of contamination through the luminal incision into the peritoneal cavity may occur. As a consequence, the sterility of the field in the peritoneal cavity in which the diagnostic or therapeutic intervention is occurring is compromised. 
       BRIEF SUMMARY 
       [0005]    One example of a device utilizing the principles of the invention includes an elongated overtube having a proximal end for location externally of a patient and a distal end for insertion into a lumen of a patient. The overtube has a centrally disposed passage extending from the proximal end to the distal end for permitting the passage of the passage of an endoscope. A tissue engaging structure is positioned on the distal end of the overtube and includes a plurality of protrusions disposed on the distal end of the overtube for mechanically engaging and securing a wall of an organ of a patient. A drive mechanism is provided for selectively moving the tissue engaging mechanism. The drive mechanism is operative to drive the plurality of protrusions into a wall of all organ and to secure the distal end of the overtube to an organ wall. 
         [0006]    In one exemplary form of the invention, the drive mechanism rotatably moves the tissue engaging structure to engage an organ wall. 
         [0007]    In another exemplary form of the invention, the plurality of protrusions includes protrusions extending in opposite circumferential directions whereby the protrusions extending in each of circumferential directions prevent relative rotational movement between the overtube and the organ wall in the opposite circumferential directions. 
         [0008]    In another example, the plurality of protrusions are circumferentially disposed about the centrally disposed passage at the distal end of the overtube. 
         [0009]    In another example, the tissue engaging structure includes a pair of counter-rotating tubes at the distal end of the overtube. 
         [0010]    In another exemplary form, the plurality of protrusions are disposed on the end surfaces of the pair of counter-rotating tubes, the protrusions on the end surfaces of one of the counter-rotating tubes extending in a first circumferential direction with the protrusions on the in surface of the other of the counter-rotating tubes extending in a second, opposite circumferential direction. 
         [0011]    In another exemplary form, the drive mechanism simultaneously rotates the counter-rotating tubes in opposite circumferential directions in time relationship to each other. 
         [0012]    In one optional form of the invention, a rupturable seal is provided in the centrally disposed passage in proximity to the distal end of the overtube for preventing contaminants from entering the centrally disposed passage. The seal preferably is formed of transparent material. 
         [0013]    Yet another example of the invention is a method of performing transluminal surgery. A first end of an overtube with an interior passage is directed into the digestive tract of a patient, and the first end is directed against a selected organ wall of the digestive tract. The first end is mechanically engaged and interconnected to the wall of the selected organ with tissue engaging structure located proximal to the first end of the overtube. With the first end of the overtube mechanically interconnected to the organ wall, an incision is made through the organ wall, and an endoscope is directed through the interior passage of the overtube into the peritoneal cavity through the incision. A surgical intervention is then performed on an organ in the peritoneal cavity. 
         [0014]    The foregoing brief description of certain examples of the invention should not be used to limit the scope of the present invention. Other examples, features, aspects, and embodiments, and advantages of the invention will become apparent to those skilled in the art from the following description, which is by way of illustration, one of the best loads contemplated for carrying out the invention. As will be realized, the invention is capable of other different and obvious aspects, all without departing from the invention. Accordingly, the drawings and descriptions you should be regarded as illustrative the nature and not restrictive. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    While the specification concludes with claims which particularly point out and distinctly claim the invention, it is believed the present invention will be better understood from the following description taken in conjunction with the accompanying drawings, in which like reference numbers identify the same elements in which: 
           [0016]      FIG. 1  is a schematic view of a human stomach with the distal end of an overtube partially inserted into the stomach; 
           [0017]      FIG. 2  is a perspective view of the overtube of  FIG. 1  showing an exemplary tissue engaging structure at the distal end and an exemplary driving mechanism at the proximal end for rotating tubular components of overtube; 
           [0018]      FIG. 3  is an enlarged perspective view of the end portion of the overtube of  FIG. 2  showing one exemplary tissue engaging structure in greater detail; 
           [0019]      FIG. 4  is fragmentary perspective view illustrating the exemplary drive mechanism shown in  FIGS. 2 and 3  in greater detail; 
           [0020]      FIG. 5  is a schematic view illustrating the distal end of the overtube of  FIGS. 1-4  engaging a wall of the digestive tract; and 
           [0021]      FIG. 6  is a perspective view of the endoscope of  FIGS. 1-5  schematically showing the overtube in fluid communication with a vacuum source. 
       
    
    
       [0022]    Reference will now be made in detail to certain exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. 
       DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0023]    Referring now to the drawings,  FIG. 1  schematically illustrates a stomach  10  of a patient into which the distal end  16  of a flexible overtube  12  has been partially inserted. The overtube  12  is formed of highly flexible biocompatible material that slides through the digestive tract with a minimum of frictional resistance. It has an elongated, generally tubular configuration with a proximal end  14  (see  FIG. 2 ) located externally of the patient and a distal end  16  (as illustrated in  FIG. 1 ) designed to be inserted into the digestive tract of a patient. In the illustration of  FIG. 1 , the distal end  16  of the overtube  12  is disposed in the patient&#39;s stomach. As those skilled in the art will readily appreciate, the overtube  12  provides a tubular passageway through which an endoscope or other instrumentation may be directed into the patient&#39;s body. In the specific illustration of  FIG. 1 , the overtube  12  has accessed the stomach  10  through the mouth of a patient. Depending upon the location of the specific portion of the digestive tract on which a diagnostic or therapeutic intervention is desired, access to the location may be made through alternative paths. For example, for a surgical intervention in the lower colon, or in a portion of the peritoneal cavity more closely positioned to the lower colon, access through the patient&#39;s anus may be preferable. 
         [0024]    The overtube  12  includes a centrally disposed tubular passage  18  extending from the proximal end  14  to the distal end  16  into which an endoscope or other instrumentation may be slidably inserted. In the specifically illustrated exemplary embodiment, the overtube  12  includes a pair of relatively movable concentrically disposed tubular components  12   a  and  12   b  (see  FIG. 3 ) respectfully driven by spur gears  20  and  22  (see  FIGS. 2 and 4 ) located on the proximals ends of the tubular overtube components  12   a  and  12   b  respectively. 
         [0025]    The distal end of the overtube  12  includes a tissue engaging structure, generally designated by the reference number  24 . As more clearly shown in  FIG. 3  and explained in greater detail below, the specifically illustrated exemplary tissue engaging structure includes a plurality of needle-like bi-directionally extending projections for mechanically engaging and securing the distal end of the overtube  12  to a wall of an organ of a patient. In the specific exemplary embodiment illustrated in  FIG. 3 , the plurality of projections are attached to tubular components  12   a  and  12   b,  with the projections  24   a  attached to tubular  10  component  12   a  projecting in a first circumferential direction and the projections  24   b  attached to tubular component  12   b  extending in a second, opposite circumferential direction. This bi-directional configuration of projections provides anti-slip functionality to the tissue engaging structure. 
         [0026]    The specifically illustrated drive mechanism for rotating tubular components  12   a  and  12   b  is more clearly shown in  FIG. 4 . As noted above, spur gear  20  is mounted to the outer peripheral surface of the proximal end of tubular component  12   a.  This spur gear  20  it is driven by a rack gear  30  which rack gear  30  is rigidly attached to a rack gear  32  having meshing teeth  33  orthogonally oriented with respect to the teeth  31  of the rack gear  30 . The rack gear  32  is, in turn, meshes with and is driven by a spur gear  34  attached to a manually rotatable knob  36 . The spur gear  34  also meshes with and engages teeth  37  of a rack gear  38  located on the opposite side of spur gear  34  from rack gear  32 . The rack gear  38  is rigidly attached to another rack gear  40 , which rack gear  40  includes teeth  41  which drivingly mesh with and engage the spur gear  22 . The spur gear  22  is rigidly attached to the outer periphery of tubular component  12   b.  Like the relationship between rack gears  30  and  32 , the teeth  37  rack gear  38  and the teeth  41  of rack gear  40  are orthogonally oriented with respect to each other. As will be apparent from the illustration of  FIG. 4 , rotation of the manual knob  36  effectuates counter-rotation of the tubular components  12   a  and  12   b  through the above-described gear arrangement. 
         [0027]      FIG. 5  shows the tissue engaging projections  24  of the specifically illustrated exemplary embodiment located on the distal end of tubular components  12   a  and  12   b  as those projections  24  engage a wall  50  of a patient&#39;s organ, such as the flexible wall of stomach  10 . When the distal end of overtube  12  is moved into contact with an organ wall  50 , such as the flexible wall of stomach  10 , the manual knob  36  is rotated. This rotation of the manual knob  36  imparts a corresponding rotation to spur gear  34 , which, in turn, imparts rectilinear movement of rack gears  30  and  32  in opposite directions. This movement of the rack gears  30  and  32  results in counter-rotational movement of spur gears  20  and  22  which, in turn, effectuates counter-rotational movement of the tissue engaging projections  24   a  and  24   b  at the distal ends of tubular components  12   a  and  12   b  respectively. 
         [0028]    As illustrated in  FIG. 5 , counter-rotation of the tissue engaging projections  24   a  and  24   b  causes such projections to engage and grasp the organ wall  50 . Having a configuration with tissue engaging members  24  that move in opposite directions, as in the exemplary embodiment illustrated in the drawings, while optional, is particularly advantageous for securing flexible tissue, such as exists in the stomach. The tissue engaging structure  24   a  moving in one direction prevents movement of the tissue wall  50  from the tissue engaging structure  24   b  moving in the opposite direction. 
         [0029]    The geometry of the tissue engaging structure  24  also is optional. In selecting the geometry of the tissue engaging structure  24 , it obviously is desirable to select a configuration that will reliably secure the distal end of the overtube  12  to the wall of the colon or stomach while simultaneously minimizing any damage to the tissue wall  50 . In the exemplary embodiment illustrated, the tissue engaging structure  24  is configured with bi-directional needle-like projections  24   a  and  24   b  formed of a shape memory material, such as, for example, a nickel titanium alloy generally known by the acronym NITINOL (an acronym for Nickel Titanium Naval Ordinance Laboratory). As specifically illustrated, the projections  24   a  of the tissue engaging structure extend from the distal end of tubular components  12   a  in a direction that is circumferentially opposite from the direction of the projections  24   b  extending from the distal end of tubular component  12   b.  As those skilled in the art will appreciate, other configurations for the tissue engaging structure may be used in accordance with the principles of the invention. For example, configurations other than the needle-like configurations illustrated may be used, and, if bi-directional structures are used to provide the tissue engaging structure with anti-slip characteristics, projections in opposite directions can extend from the same tubular component. 
         [0030]    Referring once again to  FIG. 3 , the overtube  12  optionally includes a transparent plastic film  52  in the tubular passage  18  near the distal end  16  of the overtube  12 . The plastic film  52  is sealingly engaged to the interior surface of tubular passage  18  in the tubular component  12   b  to protect an endoscope contained within the overtube  12  from contamination as the overtube  12  is moved through the digestive tract. The plastic film  52  preferably is transparent to allow the passage of light emanating from and reflected to an endoscope positioned on the proximal side of the transparent plastic film  52 . This allows a physician using an endoscope located within the tubular passage  18  of the overtube  12  to have visual access to the digestive tract while the endoscope is sealingly isolated from contaminants. The film  52  is ruptured once the distal end of the overtube  12  is secured to the organ wall  50  to permit an endoscope contained within the tubular passage  18  to extend out of the distal end of the overtube  12 . 
         [0031]    The tissue engaging structure described above can be used as the sole mechanism for securing the distal end of the overtube  12  to the organ wall  50 , or it can be used in conjunction with a vacuum assist. Referring to  FIG. 6 , the overtube  12  is the communication with a vacuum source  56  located externally of the patient, as for example, a vacuum port in a typical operating room. More specifically, the vacuum source  56  is in fluid communication with, and applies a negative pressure through the tubular passage  18  to the distal end of the overtube  12 . 
         [0032]    In use, the overtube  12  is introduced into the digestive tract, as for example through a patient&#39;s mouth or anus, and the distal end of the overtube is moved along the digestive tract until it is optimally positioned relative to the structure in the peritoneal cavity upon which a diagnostic or therapeutic intervention is desired. The distal end of the overtube  12  is then moved against the wall of the digestive tract, as illustrated in  FIG. 5 , and the knob  36  is rotated, thereby effectuating counterrotation of the tubular components  12   a  and  12   b.  This, in turn, rotates the needle-like projections  24  on tubular components in opposite circumferential directions to secure the wall of the digestive tract. With the distal end of the overtube  12  mechanically secured to the digestive tract wall by the tissue engaging structure  24  (and if a plastic film  52  is used, the plastic film  52  is ruptured), a vacuum may then be drawn through the tubular passage  18  to enhance the sealing engagement between the distal end of overtube  12  and the wall  50  of the digestive tract, more fully isolating the portion of the digestive tract wall  50  circumscribed by the end of overtube  12  from the remainder of the digestive tract. An endoscope is moved to the end of the overtube  12 , and a cutting instrument (from a working channel of the endoscope) is then used to make an incision through the digestive tract wall  50  in the isolated portion of wall  50  defined by the sealed overtube  12 . With the distal end  16  of the overttube  12  sealed and secured against the organ wall  50 , the endoscope is slid out of the opening at the distal end  16  of the overtube  12  through the incision and into the peritoneal cavity to perform the desired diagnostic or therapeutic intervention. Once the procedure on the organ in the peritoneal cavity is completed, the endoscope is withdrawn back into the overtube, and the incision is closed in a conventional fashion through instrumentation inserted into a working channel of the endoscope. Once the incision is closed, the knob  36  is rotated to release the digestive tract wall and the vacuum applied through the overtube  12  is discontinued. The overtube  12  and endoscope are then removed from the digestive tract of the patient. 
         [0033]    The device disclosed herein can be designed to be disposed of after a single use, or it can be designed to be used multiple times. In either case, however, the device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of steps of disassembly of the device followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the device can be disassembled, and any number of particular pieces or parts of the device can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular ports, the device can be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present invention. 
         [0034]    The foregoing description of preferred embodiments of the invention has been presented for purpose of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments were chosen and described in order to best illustrate the principles of the invention and its practical applications to thereby enable one of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.