Abstract:
In a first embodiment of a system for treating diseased bowel, a pair of incisions are formed on opposite ends of a diseased section of bowel. A tubular bypass implant is positioned in the bowel such that its ends are anchored within the bowel and such that an intermediate section of the implant is positioned external to the bowel such that bowel contents flow through the implant and thus around the diseased bowel section. In a second embodiment, the diseased section of bowel is removed and a system is implanted for joining limbs of the resected bowel together to form an anastomosis. In the preferred anastomosis system, the limbs of the resected bowel are positioned between a tubular sleeve extending through the bowel and a tubular cuff positioned around the bowel.

Description:
RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/818,765, filed Jul. 6, 2006. 
     
    
     TECHNICAL FIELD OF THE INVENTION  
       [0002]     The present invention relates to systems and methods for restoring function to a bowel that is obstructed by a tumor or other disease condition.  
       BACKGROUND  
       [0003]     Disease states causing bowel obstruction include colon cancer, metastatic disease that has spread to the bowel, and other forms of cancer, including pancreatic cancer that invades the walls of the bowel. Patients suffering from bowel obstruction often must undergo a surgical procedure to relieve the obstruction in order to restore bowel function. One such procedure involves a bowel resection in which a tumor or a diseased section of the bowel is removed, and the remaining portions of the bowel are joined together to form an anastomosis. If the tumor or diseased section cannot be removed, one or more bypasses around the affected area are created by resecting sections of the bowel and performing an anastomosis by suturing the remaining limbs of the resected bowel.  
         [0004]     This application describes a simplified system for joining limbs of the resected bowel together to form an anastomosis. This application further describes a bypass implant that may be used as an alternative to the conventional bypass procedure requiring resection and reassembly of the intestine.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]      FIG. 1  is a schematic illustration of a human digestive system, including the stomach, small intestine, and colon.  
         [0006]      FIG. 2  is a plan view of an embodiment of an intestinal bypass device.  
         [0007]      FIG. 3A  is a schematic view of a portion of an intestine, illustrating placement of the bypass device of  FIG. 2 .  
         [0008]      FIG. 3B  is a cross-section view taking along the plane designated  3 B- 3 B in  FIG. 3A , showing the position of an end section of the bypass device of  FIG. 2  within the intestine.  
         [0009]      FIGS. 4A-4C  are a sequence of drawings illustrating implantation of the bypass device of  FIG. 2 .  
         [0010]      FIGS. 5A-5D  are a sequence of drawings illustrating use of an anastomosis system, in which:  
         [0011]      FIG. 5A  is a side elevation view of a portion of an intestine prior to resection of a diseased section of the intestine;  
         [0012]      5 B is a side elevation view of the portion of the intestine shown in  FIG. 5A  after resection, showing the step of positioning the outer sleeve of the anastomosis system following resection of the diseased portion;  
         [0013]      FIG. 5C  is a cross-sectional side elevation view of the portion of the intestine, showing deployment of the inner sleeve of the anastomosis system; and  
         [0014]      FIG. 5D  is similar to  FIG. 5C  and shows the inner and outer sleeves following placement. 
     
    
     DETAILED DESCRIPTION  
       [0015]      FIG. 2  shows a first embodiment of a bypass device  10  for use in restoring function to a diseased bowel. Bypass device  10  includes an elongate flexible tube  12  formed of a length of tubular material including but not limited to ePTFE graft material, other polymeric tubing or fluid-tight woven polymeric material (e.g. of the type used for vascular grafts). Expandable tubular anchors  14   a ,  14   b  are positioned on each end of the flexible tube such that a continuous lumen is formed through the anchors  14   a ,  14   b  and tube  12 . The anchors may be attached to the tube  12 , or they may be attachable to the tube during implantation. Preferred anchors are formed of a material that, when positioned within a body lumen, are capable of self-expanding or being expanded into sealing contact with the walls of the lumen. Suitable materials include but are not limited to shape memory (e.g. nickel titanium alloy, nitinol or shape memory polymer) elements or stainless steel, Eligoy, or MP35N wires or structures. Each anchor may include a polymeric material on its interior and/or exterior surface, and/or the structure of the anchor (e.g. mesh, braid etc.) may be impregnated with polymeric material. In a preferred embodiment, the flexible tube  12  and the anchors  14   a ,  14   b  are radially collapsible to a reduced diameter to facilitate deployment. The device  10  may be positioned in a removable sheath  15  to maintain the reduced diameter position during deployment.  
         [0016]     The sizes of the tube  12  and anchors  14   a ,  14   b  will depend on the application, but one exemplary device may have a diameter of approximately  30  mm and a length of approximately  5  inches.  
         [0017]      FIG. 3A  shows the bypass device  10  after it has been positioned to divert bowel contents around a diseased region D of the transverse colon. The anchors  14   a ,  14   b  are disposed within the colon and make sealing contact with the walls of the colon as shown in  FIG. 3B , thus insuring that material moving through the bowel passes into the lumen  16  of the device  10 .  
         [0018]     According to one method of implanting the bypass device  10 , incisions II, I 2  are formed in the colon using an instrument  17  (e.g. mechanical or electrosurgical blade, needle, etc.) introduced into the intestinal system via the rectum and advanced through the colon. Natural orifice access systems that may be employed to access the bowel transorally or transrectally, visualize the bowel, and/or form an incision in the bowel wall are shown and described in U.S. application Ser. No. 11/528,009, filed Sep. 27, 2006, which is also incorporated herein by reference.  
         [0019]     The bypass device is retained in a radially-compressed configuration for advancement through the intestinal system. For example, the device  10  may be compressed and inserted into elongate sheath  15 . After the incisions are formed, the bypass device  10  is advanced to the implant location, preferably under endoscopic visualization, using a catheter  19  or other endoscopic device passed through the rectum. In a preferred deployment method, the bypass device  10  (with the elongate sheath  15  maintaining its compressed state) is passed through a delivery lumen in a catheter  19  having features allowing the catheter to be advanced or steered through the colon. Features of this type are found on colonoscopy devices used for diagnosis and other procedures such as polypectomy. In an alternate deployment method, the bypass device  10  and sheath may be axially advanced over a catheter or other endoscopic device advanced or to be advanced to the implantation site.  
         [0020]     The leading end of the bypass device  10 , preferably still packaged within compression sheath  15 , is advanced out of the colon via one of the incisions II, and is then fed back into the colon through the other incision I 2  as shown in  FIG. 4B . Graspers or other instruments may be passed through the diseased portion of the bowel D and used to retrieve the leading end of the device from outside the incision I 2  and withdraw it further into the colon, or to help advance the leading end further into the colon after it has been steered through the incision I 2  using the catheter. Alternatively, instruments may be passed through a port or incision formed in the abdominal wall or through the umbilicus and used to assist in passing the leading end between the incisions I 1 , I 2 . Systems for supporting instruments in single port access procedures are shown and described in U.S. application Ser. No. 11/804,063, filed May 17, 2007, which is fully incorporated herein by reference.  
         [0021]     Once the leading end of the device is in the desired location of the bowel, the sheath is partially withdrawn to expose the anchor  14   a  as shown in  FIG. 4C . The anchor preferably expands into contact with the wall of the bowel as shown in  FIG. 3B . Once it is confirmed that the trailing end of the device  10  is properly positioned, the sheath  15  is withdrawn further to expose the anchor  14   b , allowing it to seal against the interior wall of the bowel. Removal of the sheath  15  also allows the flexible tube  12  to expand to its full diameter into the position shown in  FIG. 3A .  
         [0022]     In a slightly modified embodiment, the system may include a pair of separately-removeable sheaths, one of which confines the anchor  14   a  and the other of which confines the anchor  14   b . According to this modified embodiment, the sheath covering anchor  14   a  would be withdrawn following positioning of the anchor  14   a , and the sheath covering anchor  14   b  would be removed after anchor  14   b  is positioned. Either of the sheaths might be positioned to cover the flexible tube  12 .  
         [0023]     Adhesives may be optionally used to aid in fixing the anchors within the lumen of the bowel. For example, once the anchors are positioned, an adhesive may be applied through the anchor into contact with the inner surface of the bowel. Alternatively, the anchors may include adhesives activated by light, chemical interaction, or other means once the anchors are positioned within the bowel.  
         [0024]     The device  10  and sheath  15  may be provided as a system together with additional instruments, which may include but are not limited to cutting element  17 , catheter  19 , grasper  21  and/or other instruments useful for implanting the device  10 . The system may additionally be provided with instructions for use instructing the user to implant the device using methods disclosed herein and/or their equivalents.  
         [0025]     In an alternate procedure, the bypass device  10  may be introduced laparoscopically, or using a single port formed in the abdominal wall or through the umbilicus. For example, the instruments for accessing and visualizing the bowel for forming the incision and deploying the implant  10  may be passed through the single port in the abdominal wall.  
         [0026]     A second system  20  for restoring function to a diseased bowel is shown in use in  FIG. 5D . The system  20  includes a tubular implant  22  positionable within a pair of resected limbs L 1 , L 2  of bowel having resected edges E 1 , E 1 , and an outer cuff  24  positionable around the limbs L 1 , L 2 . Tubular implant  22  is preferably formed of a material that, when positioned within a body lumen, allows the implant to self-expand or to be actively expanded (i.e. using a balloon or other device expanded within the lumen of the implant  22 ) into contact with the walls of the bowel lumen as shown in  FIG. 5D . Materials useful for the implant  22  include but are not limited to shape memory (e.g. nickel titanium alloy, nitinol or shape memory polymer) elements or stainless steel, Eligoy, or MP35N wires or structures including meshes or braids. The implant may be coated with a polymeric material on its interior and/or exterior surface, or it may be impregnated with polymer.  
         [0027]     Cuff  24  may be formed of a polymeric material or other suitable biocompatible materials. Examples include but are not limited woven or porous polymers. The cuff  24  and implant  22  are proportioned such that they will engage the limbs L 1 , L 2  between them, holding the resected edges E 1 , E 2  in contact with one another, thus helping the edges to heal together. The cuff  24  and/or implant  22  may have a material or substance on its surface (e.g., the inner surface of the cuff or the outer surface of the implant) to facilitate healing.  
         [0028]     Methods for performing an anastomosis using the system  20  may be carried out using natural orifice access (e.g. transoral or transrectal) and/or laparoscopic access. In one method of forming an anastomosis using the system  20 , a single incision or port is formed in the abdominal wall or umbilicus. Instruments for accessing and visualizing the bowel for resection and deployment of the cuff are passed through the single port. Single port access systems of the type shown and described in U.S. Application Ser. No. 11/804,063, filed May 17, 2007 and incorporated herein by reference may be used for this purpose. According to this method, diseased section D of the bowel is closed off from the adjacent limbs L 1 , L 2  using clips, sutures or other devices  26 . Diseased section D is then resected from the bowel using a cutting instrument such as a mechanical or electrosurgical blade or other cutting element. Cutting instruments suitable for this purpose include but are not limited to those currently in use for bowel resection procedures. Next, the limb sections L 1 , L 2  are inserted into the cuff  24  as shown in  FIG. 5B  and advanced longitudinally to position edges E 1 , E 2  in contact with one another.  
         [0029]     Once the edges are approximated, implant  22  is deployed within the limbs. This step may be carried out by compressing the implant into a catheter  28  and then passing the catheter into the bowel via the rectum (or, if the diseased section is in the small intestine, using transoral access through the mouth and stomach into the intestine). Natural orifice access systems that may be employed to access the bowel transorally or transrectally, visualize the bowel, and/or form an incision in the bowel wall are shown and described in U.S. application Ser. No. 11/528,009, filed Sep. 27, 2006, which is also incorporated herein by reference.  
         [0030]     The catheter  28  is advanced with its distal end beneath the distal-most limb section (relative to the catheter position) as shown in  FIG. 5C . The implant  22  is deployed from catheter as the catheter is withdrawn, causing the implant  22  to self-expand to engage the limb sections L 1 , L 2  as shown in  FIG. 5D .  
         [0031]     According to an alternative deployment method, the implant  22  is deployed prior to the cuff  24  in a manner similar to that described in connection with  FIGS. 5C and 5D . According to this embodiment, the cuff  24  may be a wrap-around device that is placed around the limbs L 1 , L 2  after the implant  22  is positioned inside the limbs. The cuff  24  can then be secured in a tubular shape using sutures or other fastening means including but not limited to adhesives, Velcro-type fasteners or other mechanical fasteners.  
         [0032]     The implant  22  and cuff  24  may be provided as a system together with additional instruments, which may include but are not limited to catheter  28  and/or other instruments useful for resecting the bowel and implanting the implant  22  and cuff  24 . The system may additionally be provided with instructions for use instructing the user to implant the implant and cuff using methods disclosed herein and/or their equivalents.  
         [0033]     While certain embodiments have been described above, it should be understood that these embodiments are presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. This is especially true in light of technology and terms within the relevant art(s) that may be later developed. Moreover, various features of the disclosed embodiments may be combined with one other or with additional features to create additional embodiments falling within the scope of the present invention.  
         [0034]     Any and all patents, patent applications and printed publications referred to above, including those relied upon for purposes of priority, are incorporated by reference.