Abstract:
A device is provided which can act as one component of an anastomosis-forming assembly, i.e. as an anastomosis button. The device comprises a plurality of elongate members having a first, introduction configuration in which they are substantially aligned with one another, and a second, use configuration in which they are disposed at an angle to one another. For example, there may be two such elongate members, which, in the use configuration, form a cross. The device comprises means, for example, a tensionable thread, for bringing the elongate members into the use configuration.

Description:
The present patent application is a continuation of International Application No. PCT/GB03/02075, filed May 14, 2003. 
    
    
     BACKGROUND 
     1. Field 
     This invention relates to methods and devices for transfixing and joining tissues and, more particularly, to forming anastomoses. 
     2. Description of the Related Art 
     In abdominal and vascular surgery anastomosis, the joining together of hollow structures, is an important goal. The ability to establish continuity between two hollow structures can relieve blockage due to cancer, inflammation or other pathology, can allow the removal of abnormal tissue or organs, and by bypassing a blocked segment, can allow the unimpeded movement of food or facilitate the flow of blood or bile through the body. 
     Anastomoses are most commonly formed at open abdominal surgery (laparotomy). Hand sewn anastomoses, usually in two or even three layers, are widely performed but are time consuming and require large incisions for hand access. Stapled anastomoses became widely performed especially in colonic surgery since they allowed surgeons to remove low rectal tumours. The short rectal remnant could be joined to the colon above the tumour at a site where it was difficult to place stitches by hand, and in consequence allowed patients to recover without needing a permanent colostomy. The advent of laparoscopic surgery staplers allowed anastomoses to be formed through incisions of 1-2 cm or so that were just large enough to allow passage of these instruments inside the abdominal or thoracic cavity. 
     Some aids so form anastomoses have been developed. J. B. Murphy, an American surgeon working in Chicago in the 1880&#39;s, popularized surgical astomoses by creating a compression button device for anastomosis. The device had two mushroom-shaped buttons, which could be placed in the two organs to be joined. The buttons could be pressed together by an internal spring in the stalk of the mushroom and the organs would be welded together by the consequent ischaemia (lack of blood supply) at the sites where the buttons were pressed together. Eventually the button device would fall through into the gut, leaving an anastomosis or hole and be passed through the body into the toilet. Compression button anastomoses are still used at open colonic surgery. The use of magnets to compress tissue to form an anastomosis has also been described, and a spring compression button method using a biofragmentable ring has been employed, especially in the rectum. 
     An anastomosis procedure has been described in an article entitled “Anastomosis at Flexible Endoscopy: an experimental study of compression button gastrojejunoscopy”, C P Swain and T N Mills, Gastrointestinal Endoscopy 1991, 37: 625-631, in which, as its title implies, a method is described of forming anastomoses using a flexible endoscope. The method described there involved introducing a flexible endoscope into one of the two structures to be joined (in this case the stomach), and entering the second of the two structures (in this case the small bowel) by forming an incision in the abdomen of the subject. The present invention is directed, in one aspect thereof, to the formation of anastomoses without the need to make such external incisions, though the invention is also applicable to the formation of anastomoses by procedures in which such incisions are made. 
     The ability to form anastomoses using flexible endoscopic or percutaneous procedures without opening the abdomen or chest or using laparoscopic methods might offer advantages especially to patients with advanced cancer or in elderly or sick patients, who might withstand conventional surgery poorly. In particular, flexible endoscopy might allow anastomoses to be formed from stomach to small bowel, duodenum to gallbladder, and small bowel to colon. 
     Flexible endoscopy allows access to many hollow organs including oesophagus, stomach, duodenum, small intestine and colon, and most flexible endoscopes have a channel through which instruments can be passed. Although the flexible endoscopes employed for most conventional purposes do not provide information on the location of tubular structures outside the organ, modified flexible endoscopes employing ultrasound are available which do. Endoscopic ultrasound is a hybrid method, which uses ultrasound imaging at the tip of the endoscope but returns the optical imaging and internal instrument channel of a conventional endoscope. Some such endoscopes have their imaging array constructed in a linear fashion, which allows good ultrasound visualization of organs adjacent to the organ in which the tip of the endoscope lies. 
     Devices are described here which can form anastomoses either through flexible endoscopes or at percutaneous needle access, which do not require surgical incision or laparoscopy (although they might be used during either of these surgical methods to form an anastomosis), and which may be used in combination with ultrasound or x-ray imaging externally to the patient or, preferably, imaging internally to the patient, for example using endoscopic ultrasound. In this situation the particular problem may arise that there may be no access to the distal side of the tissues to be joined except by making a hole through the tissues themselves, so the anastomosis-forming component on the distal side of the tissue layers must be thin enough to fit through a hole without causing excessive trauma to the tissues. 
     SUMMARY 
     According to the present invention there is provided a device adapted to act as a first component, in cooperation with a second component, for use in bringing together a first tissue layer and a second tissue layer, preferably to form a anastomosis. The device comprises a plurality of elongate members having a first configuration in which they are substantially aligned with one another, and a second configuration in which they are disposed at an angle to one another, the device comprising means for bringing the elongate members from the first configuration to the second configuration. When the elongate members are in the first configuration they are able to pass down a tube to the site of use, and then successively, through small aligned holes formed in the first and second tissue layers. When they are then brought into their second configuration their collective cross-section is such that they cannot return through those holes, and a pulling force exerted on the elongate members will tend to urge the second tissue layer towards the first. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Two embodiments of the invention are shown in the accompanying diagrammatic drawings, in which: 
         FIG. 1  shows the first embodiment with its elongate members in their first configuration; 
         FIG. 2  shows the first embodiment with the elongate members in their second configuration; 
         FIG. 3  shows the second embodiment with the elongate members in their first configuration; and 
         FIG. 4  shows the second embodiment with the elongate members in their second configuration; and 
         FIG. 5  shows an assembly which may be used to provide the second component of the anastomosis-forming device. 
     
    
    
     DETAILED DESCRIPTION 
     The first embodiment comprises two hollow tubes  1  and  2 , each having a respective bore  3 ,  4 . The bores communicate with the exterior not only at their longitudinal ends but also each communicate via a respective notch  5 ,  6  and a respective aperture  7 ,  8 , provided in their walls. The elongate members  1 ,  2  are threaded on a guide wire  9  which extends through their bores  3 , 4  and along a tube  10 , e.g. a catheter tube made of a tight wound wire sheathed in a plastics material. In this particular embodiment, the assembly is shown emerging from the biopsy channel  110  of an endoscope  100 . 
     The elongate members  1 ,  2  are brought to the intended site of use within a patient by placing the distal end of the tube adjacent that site, extending the guide wire  9  therefrom, pushing the wire through the tissues to be joined, then threading the elongate members onto the proximal end of the guide wire and running them down the interior of the biopsy channel  110  with the aid of the tube  10 . For this purpose, the internal diameter of the tube  10  must, of course, be less than the external diameter of the elongate members  1 ,  2 . If it is assumed for present purposes that the device of  FIG. 1  is to be used as one component of an anastomosis-forming device, the anastomosis being formed between first and second tissue layers, of which the first layer is that nearer to the point of entry (e.g. the mouth) of the tube into the patient, the distal end of the guide wire  9  will need to be positioned on the side of the second tissue layer which is remote from the first, and the elongate members will need to be pushed by the tube  10  through both tissue layers, so that they lie on that side of the second tissue layer. 
     As shown in  FIG. 1 , the elongate members are connected by a thread  11  which, as considered from its proximal to its distal ends, extends from outside the patient, along the gap between  10  and  110 , then into the bore  3  of the elongate member  1  via the aperture  7  and out of that bore via the notch  5 , into the bore  4  of the elongate member  2  via the notch  6 , and out of the bore  4  via the aperture  8 , at which point a knot  12  is formed which is of a greater size than can pass through the aperture  8 . 
     With the elongate members  1 ,  2  in position, the guide wire  9  is pulled back out of the elongate members  1 ,  2 , then tension is placed on the thread  11 , which causes the elongate members  1 ,  2  to assume the second configuration shown in  FIG. 2 . This configuration is in the form of a cross, with those portions of the members which have the notches  5  and  6  formed therein, engaging one another. It will be appreciated that continued tension imparted to the thread  11  causes the elongate members  1 ,  2  to bear against the remote side of the second tissue layer, drawing it towards the first. If suitable moans is provided on the proximal side of the first tissue layer to prevent its moving in response to the force applied to the distal side of the second tissue layer, the two tissue layers will be compressed, thereby providing the conditions for an anastomosis to be formed. 
     The anastomosis-forming component on the proximal side of the first tissue layer may be of any desired form and could, for example, be similar to one of the sprung mushrooms used in a Murphy button.  FIG. 5  illustrates one way of providing the proximal button. It shows an assembly that has been used in experiments where it has been placed in the stomach, and which may also be used in contents other than in conjunction with the distal component described herein. It thus represents a further inventive concept. After the endoscope has been removed, the thread  11  is threaded through the assembly which is pushed into the stomach over the guide wire  9  with the aid of a tube, such as tube  10 , passed over the thread  11  and pushing against the body of the device  220 . Once the button  200  is pressing onto the proximal side of the tissues  250  to be anatomosed, the spring  210  is compressed by pulling back on the thread  11  whilst pushing forward on the body of the device  220  with the aid of the tube  10 . The tapered hole  230  and the knot  240  act as a ratchet so that the spring remains compressed once the pushing tube  10  has been released and the excess tread proximal to the assembly has been cut. 
     Various modifications are possible to the arrangement shown in  FIG. 5  for the proximal side of the first tissue layer. For example, the device  220  can be reduced in diameter so that all or part of it can be within a channel of the endoscope, and a pushing force may be exerted on the button by the endoscope, rather than by the tube  10  as described above. 
       FIGS. 3 and 4  show a second embodiment of the invention. This comprises four elongate members. Components in this embodiment which are common to the first embodiment are given the same reference numerals as in  FIGS. 1 and 2 , and will not be described further in detail at this point. The additional elements in the second embodiment consist of two tubes  13 ,  14  and a second thread  15 . The tube  13  is threaded on the guide wire  9  intermediate the elongate members  1  and  2 , and the tube  14  is threaded on the guide wise on the distal side of the elongate member  2 . The thread  15 , as considered from one of its ends, passes parallel to the tube  10  and therefore, up to the distal end of that tube, parallel to the thread  11 , into the bore  3  of the elongate member  1  and out through the distal end of the that bore, thence successively through the bores of the tube  13 , elongate member  2  and tube  14 , from there into the bore  3  of the elongate member  1  via the notch  5  and out through the aperture  7 . This end of the thread then passes back out of the patient, running parallel to the first portion of the thread. 
     The elements of the second embodiment are positioned at the intended site of use in the same way as for the first embodiment, and tension is then imparted to both threads. This brings the device into the second configuration shown in  FIG. 4 . 
     It will be understood that although the two illustrated embodiments comprise respectively two and four elements, it is within the scope of the present invention for there to be some other number of elements, provided always that a plurality is present.