Abstract:
A system and method for endoscopically forming an anastomosis between two naturally adjacent points in the digestive tract. The system and method utilizes elongate magnetic devices that, when connected across a tissue boundary, necrose tissue until an anastomosis forms and the devices are passed naturally. Despite the elongate shape of the devices, the resulting anastomosis is substantially round. As such, round anastomoses can be formed having increased diameters merely by increasing the lengths of the devices, obviating the need for wider endoscopes.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Application Ser. No. 61/226,225 filed Jul. 16, 2009 entitled Incisionless Gastric Bypass Method And Devices, and to U.S. Provisional Application Ser. No. 61/225,901 filed Jul. 15, 2009 entitled Incisionless Gastric Bypass Method &amp; Devices, both of which are hereby incorporated in their entirety herein. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates generally to addressing problems related to the digestive system, particularly obesity and type II diabetes. Additionally, it is contemplated that the methods and devices of the present invention may be used in treating other digestive conditions such as benign or malignant obstructions of the stomach, small bowel and/or colon when clinically indicated; peptic ulcer disease; inflammatory bowel disease; adhesions; annular pancreas; duodenal, pancreatic, intestinal, or colonic primary malignancies; and secondary malignancies. 
       Obesity 
       [0003]    According to the Center for Disease Control (CDC), sixty six percent of the United States population are overweight, and thirty two percent are obese, presenting an overwhelming health problem. From an economic standpoint, it is estimated that more than 100 billion dollars are spent on obesity and treating its major co-morbidities. This figure does not include psychological and social costs. Many health care experts consider obesity the largest health problem facing westernized societies and consider obesity an epidemic. From a medical standpoint, obesity is the primary risk factor for type 2 diabetes and obstructive sleep apnea. It increases the chances for heart disease, pulmonary disease, infertility, osteoarthritis, cholecystitis and several major cancers, including breast and colon cancers. Despite these alarming facts, treatment options for obesity remain limited. 
         [0004]    Treatment options include dietary modification, very low-calorie liquid diets, pharmaceutical agents, counseling, exercise programs and surgery. Diet and exercise plans often fail because most individuals do not have the discipline to adhere to such plans. When diet and exercise fail, many try dietary supplements and drugs or other ingestible preparations promoted as being capable of suppressing appetite or inducing satiety. In general, these techniques for treating compulsive overeating/obesity have tended to produce only a temporary effect. The individual usually becomes discouraged and/or depressed after the initial rate of weight loss plateaus and further weight loss becomes harder to achieve. The individual then typically reverts to the previous behavior of compulsive overeating. 
         [0005]    Surgical procedures that restrict the size of the stomach and/or bypass parts of the intestine are the only remedies that provide lasting weight loss for the majority of morbidly obese individuals. Surgical procedures for morbid obesity are becoming more common based on long-term successful weight loss result. 
         [0006]    Bariatric surgery is a treatment for morbid obesity that involves alteration of a patient&#39;s digestive tract to encourage weight loss and to help maintain normal weight. Known bariatric surgery procedures include jejuno-ileal bypass, jejuno-colic shunt, biliopancreatic diversion, gastric bypass, Roux-en-Y gastric bypass, gastroplasty, gastric banding, vertical banded gastroplasty, and silastic ring gastroplasty. A more complete history of bariatric surgery can be found on the website of the American Society for Bariatric Surgery at http://www.asmbs.orq, the contents of which are incorporated by reference herein in their entirety. 
         [0007]    The surgeries which create malabsorption, such as the by-pass operations, although effective in weight reduction, involve permanent modification of the GI tract and have a risk of short and long term complication and even death. 
         [0008]    Gastric bypass is the most common weight loss operation in the United States. This procedure reduces the size of the stomach and shortens the effective-length of intestine available for nutrient absorption. With gastric bypass many investigators have reported weight loss results that exceed 70% of excess weight. However, this efficacy does not come without complication. The accepted mortality of the procedure is 1 in 200. Additionally, because various sections of the intestine are responsible for absorbing various nutrients from the chyme being digested, bypassing sections of the intestine can result in an inability of the modified digestive tract to benefit from certain nutrients. In certain cases, this results in conditions such as anemia and must be treated with high doses of vitamin or nutrient supplements. 
       Diabetes 
       [0009]    According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) an estimated 20.8 million people in the United States, 7.0 percent of the population, have diabetes, a serious, lifelong condition. Of those, 14.6 million have been diagnosed, and 6.2 million have not yet been diagnosed. In 2005, about 1.5 million people aged 20 or older were diagnosed with diabetes. According to the American Diabetes Association, the total annual economic cost of diabetes in 2002 was estimated to be $132 billion. 
         [0010]    Diabetes is a set of related diseases in which the body cannot regulate the amount of sugar (glucose) in the blood. Glucose in the blood provides the body with energy. In a healthy person, the blood glucose level is regulated by several hormones including insulin, glucagons, and epinephrine. Insulin is produced by the pancreas, a small organ near the stomach that also secretes important enzymes that help in the digestion of food. Insulin allows glucose to move from the blood into the liver, muscle, and fat cells, where it is used for fuel. 
         [0011]    At least 90% of patients with diabetes have Type 2 diabetes wherein the pancreas secretes insulin but the body is partially or completely unable to use the insulin. This is sometimes referred to as insulin resistance. The body tries to overcome this resistance by secreting more and more insulin. People with insulin resistance develop Type 2 diabetes when they do not continue to secrete enough insulin to cope with the higher demands. 
         [0012]    Recently, evidence for reduction of complications of type 2 diabetes with tight control of hyperglycemia has been reported, but current therapies, including diet, exercise, behavior modification, oral hypoglycemic agents, and insulin, rarely return patients to euglycemia. 
         [0013]    For reasons not completely known, the majority of patients who undergo gastric bypass surgery experience resolution of Type 2 diabetes and enjoy normal blood glucose and glycosylated hemoglobin levels with discontinuation of all diabetes-related medications. One hypothesis, that has been proposed, is that diabetes control results from the expedited delivery of nutrient-rich chyme (partially digested food) to the distal intestines, enhancing a physiologic signal that improves glucose metabolism, the so called “hindgut hypothesis”. However, because gastric bypass surgery is considered a relatively high-risk major surgery, it is not used to treat Type 2 diabetes. 
       OBJECTS AND SUMMARY OF THE INVENTION 
       [0014]    The methods and devices of the present invention are primarily directed to a minimally invasive, endoscopic solution for treating patients with obesity and/or Type 2 diabetes. The methods and devices can also be of benefit in laparoscopic and open surgical procedures. The solution is simple, user-friendly, reversible, and does not require a permanent implant. When the procedure is performed endoscopically, the need for abdominal incisions is eliminated. Thus, the procedure has the potential of being performed outside of the operating room, potentially in an endoscopy suite. 
         [0015]    One aspect of the present invention treats the aforementioned conditions by creating a partial bypass of a portion of the small intestines. Preferably, an anastomosis is created between the distal portion of the second section and/or third section of the duodenum and the ileum or colon. Using anatomical landmarks as reference, the anastomosis should preferably be positioned in the duodenum distal to the hepatopancreatic ampulla where the common bile and main pancreatic duct empty into the duodenum and proximal to the point where the superior mesenteric artery and vein cross over the duodenum. 
         [0016]    This solution creates an alternative pathway for chyme. A portion of the nutrients will bypass a portion of the small intestines and thus not be absorbed (controlled absorption). The amount of bypass is controlled by the size of the anastomosis. The physician is thus able to vary the size of the anastomosis both at the time of the procedure and during subsequent follow-up procedures. The anastomosis also provides a bypass for nutrient-rich chyme to enter the ileum or colon. This is thought to have the effect of triggering early satiety as well as improving glucose metabolism. A potential candidate mediator of this effect is glucagon-like peptide 1 (GLP-1). This incretin hormone is secreted by cells in the distal bowel in response to nutrients, which stimulates insulin secretion. 
         [0017]    Another aspect of the present invention provides a method by which an endoscope is inserted orally and advanced through the upper GI track and then into the duodenum. Another endoscope is inserted anally and advanced into the colon or ileum. The normal anatomy in a human is such that the second and third sections of the duodenum are in close proximity with portions of the ileum and colon. If either structure is illuminated from within, it can readily be seen from the other. For example, if the duodenum is illuminated, the light can be seen with an endoscope in the ileum or colon and the ileum or colon can then be gently maneuvered such that it is touching the duodenum. The ileum or colon can also be positioned by visualizing the endoscopes using fluoroscopic imaging and maneuvering the endoscope within the ileum or colon to close proximity of the endoscope in the duodenum. 
         [0018]    Once intimate contact has been confirmed between the duodenum and the ileum or colon, magnets that have been pre-attached to the endoscope are coupled. In another embodiment of the invention magnets are passed through the working channel of the endoscope rather than pre-attached. Once the magnets have been magnetically coupled and alignment is verified utilizing endoscopic and/or fluoroscopic imaging, they are released from the endoscopes. The two coupled magnets create intimate contact between the serosal surfaces of the two vessels. During the healing period the tissue between the magnets is compressed and becomes necrotic. The tissue near the outside of the anastomosis device is compressed at a lower force. This tissue forms a region or ring of healed tissue. After a few weeks the necrotic tissue, along with the magnetic implants detach and are expelled. There is no flow between vessels during the healing period. Everything flows through the natural distal duodenum and thus there is no risk of obstructing flow. Human serosal tissue that is placed in intimate contact has been shown to heal within 7 days. 
         [0019]    Patients can be tracked and if absorption needs to be further limited a follow up procedure can be performed to create additional anastomosis in the same or other locations or make the anastomosis larger. Likewise, if the anastomosis is too large, it may be modified by closing a portion of the anastomosis with an endoluminal suturing, stapling, or clip device. The procedure may be completely reversed by closing the entire anastomoisis with such devices. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIGS. 1-5  are views of the digestive system showing a progression of steps of an embodiment of a method of the present invention for creating a duodenum to colon anastomosis; 
           [0021]      FIG. 6  is a partial view of the digestive system with an anastomosis formed by an embodiment of a method of the present invention; 
           [0022]      FIGS. 7-10  are views of the digestive system showing a progression of steps of an embodiment of a method of the present invention for creating a partial bypass with a side-to-side anastomosis between the duodenum and ileum; 
           [0023]      FIG. 11   a  is a perspective view of an embodiment of a device of the present invention attached to an embodiment of a delivery device of the present invention; 
           [0024]      FIG. 11   b  is a perspective view of the device of  FIG. 11   a  being released from the delivery device of  FIG. 11   a;    
           [0025]      FIG. 12   a  is an end view of an embodiment of a device of the present invention attached to an embodiment of a delivery device of the present invention; 
           [0026]      FIG. 12   b  is a section view taken along lines A-A of  FIG. 12   a;    
           [0027]      FIG. 13  is a plan view of an embodiment of a device of the present invention attached to an embodiment of a delivery device of the present invention; 
           [0028]      FIG. 14  is an elevation of an embodiment of a device of the present invention attached to an embodiment of a delivery device of the present invention; 
           [0029]      FIG. 15  is a side elevation of a pair of devices of an embodiment of the present invention being implanted in adjacent body lumens to form an anastomosis therebetween; 
           [0030]      FIG. 16   a  is a perspective view of an embodiment of a device of the present invention attached to an embodiment of a delivery device of the present invention; 
           [0031]      FIG. 16   b  is a perspective view of the device of  FIG. 16   a  being advanced from a distal end of the delivery device of  FIG. 16   a;    
           [0032]      FIG. 16   c  is a perspective view of the device of  FIG. 16   a  being released from the delivery device of  FIG. 16   a;    
           [0033]      FIG. 17   a  is an end view of an embodiment of a device of the present invention attached to an embodiment of a delivery device of the present invention; 
           [0034]      FIG. 17   b  is a section view taken along lines B-B of  FIG. 17   a;    
           [0035]      FIG. 18   a  is a perspective view of an embodiment of a device of the present invention attached to an embodiment of a delivery device of the present invention; 
           [0036]      FIG. 18   b  is a perspective view of the device of  FIG. 18   a  being advanced from a distal end of the delivery device of  FIG. 18   a;    
           [0037]      FIG. 18   c  is a perspective view of the device of  FIG. 18   a  being released from the delivery device of  FIG. 18   a;    
           [0038]      FIG. 19  is a detail view of area A of  FIG. 18   b;    
           [0039]      FIG. 20  is a detail view of area B of  FIG. 18   c;    
           [0040]      FIG. 21   a  is an end view of an embodiment of a device of the present invention attached to an embodiment of a delivery device of the present invention; 
           [0041]      FIG. 21   b  is a section view taken along lines C-C of  FIG. 21   a;    
           [0042]      FIG. 21   c  is a section view taken along lines D-D of  FIG. 21   a;    
           [0043]      FIG. 22  is a cutaway view of an embodiment of a device of the present invention loaded into an embodiment of a delivery device of the present invention; 
           [0044]      FIG. 23   a  is a perspective view of an embodiment of a device of the present invention attached to an embodiment of a delivery device of the present invention; 
           [0045]      FIG. 23   b  is a perspective view of the device of  FIG. 23   a  being released from the delivery device of  FIG. 23   a;    
           [0046]      FIG. 24   a  is a perspective view of an embodiment of a device of the present invention attached to an embodiment of a delivery device of the present invention; 
           [0047]      FIG. 24   b  is a perspective view of the device of  FIG. 24   a  being advanced from a distal end of the delivery device of  FIG. 24   a;    
           [0048]      FIG. 24   c  is a perspective view of the device of  FIG. 24   a  being released from the delivery device of  FIG. 24   a;    
           [0049]      FIG. 24   d  is a detail view of area C of  FIG. 24   c;    
           [0050]      FIG. 25  is a comparison of device shapes and resulting anastomosis shapes. 
           [0051]      FIG. 26  is a perspective view of an embodiment of a delivery device of the present invention being used to deliver an arrangement of two devices according to an embodiment of the present invention; 
           [0052]      FIG. 27  is a perspective view of an embodiment of a delivery device of the present invention being used to deliver an arrangement of two devices according to an embodiment of the present invention; 
           [0053]      FIG. 28  is a perspective view of an embodiment of a delivery device of the present invention being used to deliver an arrangement of four devices according to an embodiment of the present invention; 
           [0054]      FIGS. 29   a - d  are a progression of perspective views of an embodiment of a delivery device of the present invention releasing an embodiment of a device of the present invention; 
           [0055]      FIG. 30   a  is a perspective view of an embodiment of a device of the present invention attached to an embodiment of a delivery device of the present invention; 
           [0056]      FIG. 30   b  is a perspective view of the device of  FIG. 30   a  being advanced from a distal end of the delivery device of  FIG. 30   a;    
           [0057]      FIG. 30   c  is a perspective view of the device of  FIG. 30   a  being released from the delivery device of  FIG. 30   a;    
           [0058]      FIG. 31   a  is a perspective view of an embodiment of a device of the present invention attached to an embodiment of a delivery device of the present invention; 
           [0059]      FIG. 31   b  is a perspective view of the device of  FIG. 31   a  being advanced from a distal end of the delivery device of  FIG. 31   a;    
           [0060]      FIG. 31   c  is a perspective view of the device of  FIG. 31   a  being released from the delivery device of  FIG. 31   a;    
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0061]    The invention provides for the method and device apparatus to create a partial bypass between the duodenum and ileum or duodenum and colon utilizing a completely incisionless endoscopic method using both the mouth and anus as natural pathways for gaining access to the preferred anastomosis location. An important aspect of the invention is that the anastomosis is created between naturally adjacent or close proximity sections of the duodenum and ileum or duodenum and colon, therefore allowing a means for a totally incisionless procedure. The invention generally involves inserting a first endoscopic delivery device orally into the duodenum. A similar second endoscopic delivery device is inserted anally into the colon or the ileum to a position where the tracts of the ileum or colon naturally lie adjacent or in close proximity to the duodenum. Having been pre-assembled at the distal tip of the endoscopic delivery device or advanced through a channel of the endoscope or overtube, the magnetic implants are subsequently aligned and magnetically coupled. The implant devices are magnetically attracted to each other (one or both being magnets) and are aligned to one another using visual and/or fluoroscopic guidance and released from their respective deployment devices. The magnetic implants apply force to the vessel walls trapped between them and pressure necrosis preferably results within a few weeks. The circumferential tissue near the edge of the magnetic devices is of lower pressure and creates a healed continuous region of tissue between the vessels. After an appropriate period of time, the coupled magnetic devices and compressed necrotic tissue detach from the surrounding tissue therefore creating an anastomosis. Subsequently, the magnetic implants pass through the digestive tract leaving no permanent implant in the body. A first series of device embodiments of the invention illustrate using magnetic implants that are pre-assembled to the distal tip of the endoscope. A second series of embodiments of the invention illustrates using magnetic implants that are advanced through the working channel of an endoscope instead of pre-assembled at the distal tip. A third series of embodiments illustrates releasably attaching the magnetic devices to an overtube that surrounds the endoscope as well as advancing the devices through a lumen within the wall of an overtube. 
         [0062]    As shown in  FIG. 1 , the digestive tract  10  includes the esophagus  12 , which empties into the stomach  14 . Distal to the stomach is the small intestine, which is comprised of the duodenum  16 , jejunum  18 , and ileum  20  sections. The ileum  20  empties into a part of the colon  22  called the cecum. The colon generally consists of five main segments: ascending  22   a,  transverse  22   b,  descending  22   c,  sigmoid  22   d,  and rectum  22   e.    
         [0063]      FIG. 6  shows the various segments of the duodenum and anatomical landmarks within and around the duodenum. The duodenum consists of four segments: superior  16   a,  descending  16   b,  horizontal  16   c,  and ascending  16   d.  In this figure, a section of the transverse colon has been removed to view the anatomical landmarks near the duodenum more clearly. Generally, the common bile and pancreatic ducts combine into the hepatopancreatic ampulla  24  which empties into the descending duodenum  16   b  approximately two-thirds along its length. The superior mesenteric artery and vein  26  cross the horizontal duodenum segment  16   c  at its distal end. 
         [0064]    Although an anastomosis could be made anywhere in the duodenum to the ileum or colon, the preferred duodenal location for the anastomosis  28  is in the distal third of the descending segment  16   b  and/or the horizontal segment  16   c  of the duodenum, provided that the anastomosis is distal to the hepatopancreatic ampulla  24  and proximal of the superior mesenteric artery and vein  26 . Creating the anastomosis distal to the common bile and pancreatic ducts will allow their contents to flow in the newly created partial bypass as well as in the original natural tract. Positioning the anastomosis proximal of the supererior mesenteric artery and vein provides many benefits: 1) access is easier than going more distal, 2) the malabsorptive effect will be enhanced from bypassing the duodenum more proximally, 3) the position is ideal for connecting the duodenum to naturally adjacent segments of the colon and ileum, and 4) connecting proximal of the superior mesenteric artery and vein avoids potential complications of placing devices on or directly adjacent the wall of the superior mesenteric artery and vein. 
         [0065]    Referring to  FIGS. 1 and 6  for the duodenum to colon side-to-side anastomosis, the invention takes into account that the transverse colon  22   b  naturally lies on top of (superior) the preferred location in the duodenum  28  as described above, in which, the superior wall of the duodenum is adjacent the posterior wall of the transverse colon  22   b.  Creating an anastomosis between naturally adjacent tracts simplifies the procedure of accessing the anastomosis sites and aligning the anastomosis devices into correct position. This is especially evident for a duodenum to transverse colon anastomosis as it is of common practice and skill level for endoscopists to access these locations in the digestive tract. Although advanced access tools such as single or double balloon enteroscopy may be used, this anastomosis location allows the use of standard endoscopic devices to access the duodenum and transverse colon. 
         [0066]    A first endoscopic delivery device  30   a  is inserted orally and advanced through the esophagus  12 , stomach  14 , and into the duodenum  16 . The endoscopic delivery device  30   a  consists of a pre-assembled endoscope  32   a,  delivery catheter  34   a,  and magnetic implant  36   a.  The magnetic implant  32   a  is releasably attached to the distal tip of the delivery catheter  34   a  which has been loaded into a working channel of the endoscope  32   a.    
         [0067]    Similarly, a second endoscopic delivery device  30   b  is inserted through the anus  22   f  and advanced into the transverse colon  22   b.  In similar fashion, the endoscopic delivery device  30   b  consists of a pre-assembled endoscope  32   b,  delivery catheter  34   b,  and magnetic implant  36   b.  The magnetic implant  32   b  is releasably attached to the distal tip of the delivery catheter  34   b  which has been loaded into a working channel of the endoscope  32   a.    
         [0068]    Once the first  30   a  and second  30   b  endoscopic delivery devices are roughly positioned into the duodenum  16  and transverse colon  22   b  as shown in  FIG. 1 , the operator should confirm that the endoscopes are in adjacent vessels with close proximity. This may be accomplished by visualizing the light source emitted from the first endoscope by the second endoscope. For example, the light source emitted by the endoscope  32   a  in the duodenum  16  should be easily viewed by the endoscope  32   b  in the transverse colon  22   b  and vise-versa. Additionally, or instead of the light source, the position of the first endoscope to the second may be verified by visualizing the first endoscope touching and moving the wall of the vessel of the second endoscope. For example, the first endoscope  32   a  in the duodenum  16  may be articulated to touch and displace the wall of both the duodenum and the adjacent wall of the transverse colon. The second endoscope in the transverse colon  22   b  would view the resulting wall motion to confirm the proximity of the first endoscope in the duodenum. An additional and preferred method of confirming that the endoscopes are in adjacent vessels of close proximity is to use fluoroscopy to confirm the position and aid in guiding the magnetic implants into their final coupled position. For example, if the distal end of the roughly positioned endoscopic delivery device  30   a  in the duodenum  16  is not in close proximity and adjacent to the distal end of the endoscopic delivery device  30   b  in the transverse colon  22   b,  fluoroscopy may be used to articulate the distal tip of the endoscopic delivery devices and their respective vessels into final position. This is accomplished by manipulating and articulating the endoscopes  32   a  and  32   b,  the delivery catheters  34   a  and  34   b,  and/or the magnetic implant  36   a  and  36   b.  The delivery catheter  34  is designed to move axially within the working channel of the endoscope  32  and may also be designed so that its distal tip may articulate the attached magnetic implant  36 . The magnetic implant  36  may be positioned axially or radially by advancing or rotating the delivery catheter  34  relative to the endoscope  32 . Contrast may be injected into the duodenum  16  and transverse colon  22   b  during fluoroscopy to visualize the vessels and help bring them into proximity to one another by articulating and manipulating the devices. Once brought into close proximity, the magnetic implants will couple and self align as shown in  FIG. 2 . Once coupled, the magnetic implant in the duodenum should be visually inspected to make sure it is in the preferred position  28  as described previously and shown in  FIG. 6 . Additionally, fluoroscopy may be used to verify that the magnetic implants are properly oriented and contrast may be injected to show that the vessels remain adjacent and are not adversely twisted. If the magnetic implants are not properly aligned or the vessel wall has been adversely deformed, the magnetic implants may be pulled apart and repositioned using the same techniques as described above. Once the operator is satisfied with the positioning of the magnetic implants and vessel geometry, the coupled magnetic implants  36   a  and  36   b  are released from their respective delivery catheters  34   a  and  34   b  and the endoscopic delivery devices are removed from the body. If the implants need to be repositioned or removed after release, it is preferable that the implants could be easily recaptured using the same endoscopic delivery devices. 
         [0069]      FIG. 3  shows a lateral view of  FIG. 2  of the coupled magnetic implants  36   a  and  36   b  after they have been released from the delivery catheters  34   a  and  34   b.  The magnetic implants  36   a  and  36   b  compress the duodenal and colon wall between them which results in ischemic pressure necrosis of the tissue trapped between them. The surrounding circumferential tissue is compressed at a lower force and results in a healed continuous region or ring of tissue between the vessels around the magnetic implants. After an appropriate period of time, the coupled magnetic implants and compressed necrotic tissue detach from the surrounding tissue and therefore create an anastomosis. Once detached, the implants pass through the digestive tract, leaving no device in the body.  FIG. 4  illustrates the anastomosis after the magnetic implants have detached from the surrounding tissue and are about to start their journey out of the digestive tract.  FIG. 5  shows the preferable path the magnetic implants take to be eliminated from the digestive tract. No permanent implant is left in the body. Although not ideal, the magnetic implants may start their journey by traveling down the duodenum instead of the colon side of the anastomosis. This may take longer for the implants to exit the body as they are taking a longer pathway. It is also contemplated that if they initially started down the duodenum (long path) that once they reach the colon side of the anastomosis that they could pass through the anastomosis and travel down the duodenum side a second time. 
         [0070]    Notice in  FIG. 4  and  FIG. 5  the resulting anastomosis creates a partial bypass where chyme may take one of two paths: 1) the original natural path through the duodenum and on to the jejunum or 2) the new path created with the anastomosis to the transverse colon  22   b.  It is the object of this invention to leave the original natural path in place so that chyme, bile, and other digestive juices may travel down both paths. Chyme that takes the new path will bypass a portion of the small intestines and therefore not be absorbed. The ratio of chyme going through the new path may be dependent on the size of the anastomosis relative to the original vessel size. The size of the anastomosis may be tailored by the physician at the time of the procedure and during subsequent follow-up procedures. For example, if the first anastomosis was not large enough to create the desired effect, the physician could enlarge the first anastomosis with another device or create a second anastomosis preferably after the first anastomosis device had exited the body. Alternatively, if the first anastomosis was too large or the procedure needed to be reversed, the physician could partially or completely close the anastomosis with a transluminal suturing, stapling, or clip device. The anastomosis also provides a bypass for nutrient-rich chyme to enter the ileum or colon. This is thought to have the effect of triggering early satiety as well as improving glucose metabolism. A potential candidate mediator of this effect is glucagon-like peptide 1 (GLP-1). This incretin hormone is secreted by cells in the distal bowel in response to nutrients, which stimulates insulin secretion. 
         [0071]    The present invention also contemplates a duodenum to ileum anastomosis, taking into account that a portion of the ileum  20  naturally lies adjacent or in close proximity to the preferred location in the duodenum  28  as described above. Although the ileum is a more difficult region to access than the transverse colon from the large intestines, using adjacent tracts will simplify locating and aligning the duodenum and ileum vessels and magnetic anastomosis devices to one another. Advanced access tools such as single and double balloon enteroscopy devices may be used to access this location. It is preferable that an anastomosis device and delivery system work in conjunction with advanced access tools and techniques. 
         [0072]    It should also be noted that use of the term “adjacent to” or “in close proximity to” as used herein accounts for anatomical variations, which may account for a separation of up to a few inches. It is well within the scope of the present invention to use the distal ends of the probes/endoscopes to move the digestive tract slightly to establish a magnetic connection. Notably, unlike prior art references that puncture the digestive tract with additional probes in order to manipulate anatomy while establishing connections (see e.g. U.S. Patent Publication 2008/0208224 to Surti et al.), the devices and methods of the present invention have been found to easily manipulate portions of the digestive tract significant distances by simply advancing the probes/endoscopes into the lumen walls of the bowels. Hence, it is contemplated that the present invention encompasses doing so, preferably without making a single incision or puncture through patient tissue. 
         [0073]      FIGS. 7-10  show in stepwise fashion an incisionless method for creating a partial bypass with a side-to-side anastomosis between the duodenum  16  and ileum  20 . A first endoscopic delivery device  30   a  is inserted orally and advanced through the esophagus  12 , stomach  14 , and into the duodenum  16 . The endoscopic delivery device  30   a  consists of a pre-assembled endoscope  32   a,  delivery catheter  34   a,  and magnetic implant  36   a.  The magnetic implant  36   a  is releasably attached to the distal tip of the delivery catheter  34   a  which has been assembled into a working channel of the endoscope  32   a.    
         [0074]    A second endoscopic delivery device  30   b  is inserted through the anus  22   f,  advanced into the ascending colon  22   a,  and further advanced into the ileum  20 . In similar fashion, the endoscopic delivery device  30   b  consists of a pre-assembled endoscope  32   b,  delivery catheter  34   b,  and magnetic implant  36   b.  The magnetic implant  36   b  is releasably attached to the distal tip of the delivery catheter  34   b  which has been loaded into a working channel of the endoscope  32   b.    
         [0075]    The rough position of the magnetic implants  36   a  and  36   b  and vessels  16  and  20  are respectively confirmed and finely positioned using the same method as described previously.  FIG. 8  shows the magnetic implants  36   a  and  36   b  coupled together after the vessels are positioned appropriately according to the previously described method.  FIG. 9  shows the magnetic implants  36   a  and  36   b  after they have been released from the delivery catheters  34   a  and  34   b.  The magnetic implants apply force for a period of time sufficient for pressure necrosis to create the anastomosis.  FIG. 10  illustrates the anastomosis after the magnetic implants  36   a  and  36   b  have detached from the surrounding tissue and are about to start their journey out of the digestive tract.  FIG. 10  also shows the preferable path the magnetic implants take to be eliminated from the digestive tract. No permanent implant is left in the body. Although not ideal, the magnetic devices may start their journey by traveling down the duodenum instead of the ileum side of the anastomosis. This may take longer for the implants to exit the body as they are taking a longer pathway. It is also contemplated that if they initially started down the duodenum (long path) that once they reach the ileum side of the anastomosis that they could pass through the anastomosis and travel down the duodenum a second time. As described previously, the anastomosis size may be subsequently altered in a second procedure. 
         [0076]    The devices used to deploy and create the anastomoses in the previously described methods for creating a partial bypass between the duodenum and transverse colon and duodenum to ileum will now be explained in greater detail. For simplicity, most of the figures will only show one device in each figure, however, it is assumed that a second, preferably nearly identical, device will be needed to create the anastomosis as shown in the methods previously described for creating a duodenum to ileum or colon anastomosis. The endoscope used in the embodiments may be different if deploying a magnetic implant in the upper gastrointestinal tract such as the duodenum than an implant deployed in the ileum or colon. For example, a gastroscope may be used with the devices delivered into the duodenum and a colonoscope may be used with devices delivered into the colon or ileum. Also, the magnet in the second device will be assembled in the opposite polarity from the first so that the first and second implant attract instead of repel each other. Although not an all inclusive list, many embodiments will be described so that those skilled in the art will appreciate that variations upon these embodiments are within the spirit of the invention. 
         [0077]      FIG. 11   a  shows an embodiment of a device usable to carry out the methods described previously, in that, the endoscopic delivery device  30  consists of a pre-assembled endoscope  32 , delivery catheter  34 , and implant  36 . The delivery catheter  34  is loaded into the working channel  38  of the endoscope  32  and the implant  36  is releasably attached to the distal end of the delivery catheter  34  using a snare  42  that is wrapped around a knob feature  40  integral to the magnetic implant  36 . The implant  36  is docked onto the delivery catheter  34  by applying tension to the snare wire  42  relative to the delivery catheter and locking the wire relative to the delivery catheter in a handle set that would be positioned at the proximal end of the delivery catheter. 
         [0078]    The implant  36  is used in conjunction with a second implant  36 . The two implants  36  are attracted to each other magnetically, at least one of which being a magnet. Hence, as used hereinafter when describing the remaining device embodiments, each implant will be referred to as a magnetic implant. This is to be interpreted as meaning the implant contains a magnet or an element that is attracted to a magnet and should not be interpreted as being limited to only magnets. 
         [0079]      FIG. 11   b  illustrates unlocking the snare wire  42  and releasing the magnetic implant  36 . The snare  42  is preferably formed of braided stainless steel cable or nitinol wire so that when the snare is unlocked to release the magnetic implant  36  it grows to a pre-formed size so that it may be easily released from the knob  40 . Once the implants have been released, the snare may also be used to recapture the implant by re-snaring the knob on the implant. Although an external means for releasably attaching the implant to the delivery catheter using a knob feature has been shown, an implant housing is contemplated with internal releasable attachment features. The implants may be pulled apart by pulling on the delivery catheter. Once pulled apart, they may be repositioned or removed from the body. 
         [0080]      FIG. 12  shows a cross section of the distal portion of the endoscopic delivery device  30  in its locked condition. The magnetic implant  36  consists of a magnet  44  and housing  46 . The housing consists of a top  48   a  and bottom  48   b.  The top  48   a  contains a knob feature  40  for holding onto the magnetic implant  36  with a snare  42 . The magnetic implant incorporates rounded atraumatic features for ease of tracking the device through the body lumen prior to coupling and after the anastomosis has been created when the magnetic device/implant is exiting the body. The magnetic implant is preferably longer than it is wide and attached to the delivery catheter  34  so that the length is axially aligned with the endoscope  32 . This small profile of the device relative to the profile of an endoscope aids in tracking the device ahead of the endoscope and allows variable length devices to be used depending on the size of anastomosis required. Additionally, the alignment of the magnetic implant aids in creating a side-to-side implant coupling and resulting anastomosis between vessels that are in close proximity or adjacent and aligned as shown in  FIG. 15 . 
         [0081]      FIGS. 13-15  illustrate the movement and flexibility of the delivery catheter  34 . The delivery catheter may move axially and be rotated relative to the endoscope  32 . Having the ability to telescope out of the endoscope and rotate the magnetic implant  36  may allow the operator ease of accessing the target locations within the body as well as finely positioning the vessels and magnetic implants both axially and radially for coupling. As shown in  FIG. 15 , in this embodiment the delivery catheter  34   a  and attached magnetic implant  36   a  lead the endoscope  32   a  as it is tracked through the body vessel. Therefore, it may be advantageous if the distal tip of the delivery catheter is steerable to aid in tracking of the devices through the digestive tract.  FIG. 13  shows a delivery catheter which articulates the magnetic implant in one direction while  FIG. 14  shows a delivery catheter that articulates approximately orthogonal to the direction shown in  FIG. 13 . The catheter may be fabricated to have no articulation, or articulation in one direction, or articulation in the orthogonal direction, or both. The delivery catheter  34  preferably has excellent torsional stiffness so that it can rotate the magnetic implant  36  yet is flexible enough to allow the implants to easily attract and couple together. 
         [0082]    For example,  FIG. 15  shows two magnetic implants  36   a  and  36   b  coupled together in adjacent vessels. The figure shows that the axes of the endoscopes  32   a  and  32   b  are not aligned with the axis of the magnetic implants  36   a  and  36   b.  This is possible because the delivery catheters  34   a  and  34   b  are flexible and conform to the coupled magnetic implants  36   a  and  36   b.  The torsional stiffness and flexibility of the delivery catheter  34  may aid the operator with aligning and coupling the magnetic implants  36  so that the more rigid endoscopes do not have to be perfectly aligned in order for the magnetic implants  36   a  and  36   b  to couple. However, the flexibility of the endoscopes may be adequate to aid in coupling of the magnetic implants  36  and it may not be necessary to have a flexible catheter  34  to aid in coupling. The delivery catheters  34  preferably have good tensile strength so that they can easily pull the magnetic implants  36  apart should they need to be repositioned or removed. The delivery catheters  34  are preferably formed using standard component guide catheter techniques and may be constructed of a lamination of a Teflon liner, a high density stainless steel braid, and a polymer outer jacket. The delivery catheter may be coated with a lubricious coating to aid in advancing down the lumen of the endoscope and in the body vessel. Also, the implant may be coated with a lubricious coating to aid in advancing through the body vessel. The coating may be a silicone or hydrophilic coating. 
         [0083]    Since the size of the anastomosis may affect the results of the partial bypass on weight loss or diabetes resolution, it is advantageous that a wide range of magnetic implant sizes are available to meet the needs of the range of sizes of human vessel anatomy. One aspect of the invention is that the resulting anastomosis size and shape is governed by the magnetic implant circumference and not necessarily its shape. As shown in  FIG. 25  for example, if an anastomosis size of approximately 1.5″ diameter was required, the operator could implant a round magnet  50  with a 1.5″ diameter and a resulting approximately round anastomosis  52  of 1.5″ diameter would result after healing was complete. However, tracking a round magnet  50  that was not collapsible through the digestive system would prove difficult as most endoscope diameters are approximately 0.5 inches by comparison. Alternatively, an approximately 1.85″ long×0.375″ wide magnet  54  of equal circumference to the round magnet  50  could easily be tracked through the digestive system if the long end of the magnet was aligned and advanced axially ahead of the endoscope. This implant would also create an approximately round anastomosis  56  of 1.5″ diameter after healing was complete because even though the coupled magnetic implants will create a necrotic core of tissue the same size and shape as the magnets, the body over time remodels the shape of the implant to the native vessel shape which is approximately round. Hence, as the circumference of an elongate, relatively rectangular magnet having a width (w) and a length (l)=2(w)+2(l), and the circumference of a relatively round anastomosis has a circumference=2Πr. Therefore for a given desired implant width (w), the implant length (l) required to make an anastomosis having a desired radius (r) becomes Πr−w. With this in mind, typical endoscope working channels range in inner diameter from 1.5 mm to 7 mm. Thus, the magnetic implant widths (w) preferably fall within this range and, given the application discussed herein, and the most common endoscopes on the market, more preferably fall within the range of 1.5 mm to 3.7 mm. 
         [0084]    Returning to  FIG. 12 , the magnet  44  is preferably a neodymium rare earth magnet. The magnetic poles are aligned through the thickness of the magnet so that the maximum magnetic force is achieved when the magnetic implants  36   a  and  36   b  are coupled as shown in  FIG. 15 . The bottom of the housing  48   b  can be smooth or have a surface roughness as the magnetic implants will align in either case because the inner lining of the vessels are very lubricious. Although lubricious, a rough surface on the bottom of the housing  48   b  may be advantageous once the magnets are coupled to prevent them from decoupling due to shear forces. The magnetic implant  36  may contain one magnet as shown in  FIG. 12  or multiple smaller magnets. The housing  46  may be larger than the magnet  44  to distribute the magnetic force over a larger area. The housing  46  may be formed out of metal such as stainless steel, titanium, or other medical implant grade metals. Alternatively, the housing may be made of silicone or other medical implant grade polymers. Sections of the housing may be made out of biodegradable material. For instance, the knob  40  may be overmolded with biodegradable material onto the housing so that the knob would biodegrade after the magnetic implants are coupled. This would create a smaller profile of the coupled magnetic implants and may be easier to pass through the body once the anastomosis is created. The housing  46  may be formed of a top  48   a  and bottom  48   b  piece as shown or may be one integral body if formed using molding techniques. The housing&#39;s main functions are to provide a protective coating around the magnetic so that is does not corrode should it crack or fracture, provide attachment means to hold onto the magnet, distribute the force of a magnet over a surface area, and provide an atraumatic surface that passes easily through the digestive system. Although not preferred, a magnetically attracted ferrous metal core may take the place of the magnets in one of the magnetic implants. For instance, using  FIG. 15  as a reference, the magnetic implant  36   a  may contain a neodymium magnet  44   a  while the second implant  36   b  may contain a magnetically attracted ferrous metal core instead of a neodymium magnet  44   b  as shown in  FIG. 15 . The ferrous metal core would preferably be the same size and shape as the neodymium magnet it replaces. 
         [0085]      FIGS. 16   a - 16   c  show an alternative embodiment of an endoscopic delivery device  130  used according to the methods described previously to create a duodenum to transverse colon or ileum anastomosis. This embodiment is similar to the previous embodiment except that the magnetic implant geometry has changed to allow the implant to attach to the side of the endoscope while accessing the target anastomosis location.  FIG. 16   a  shows a magnetic implant  136  docked to the end of an endoscope  132 . The mafority of the magnetic implant is long and thin except for the distal tip which contains a knob  140  similar to the previous embodiment. Most of the length of the magnetic implant resides on the side of the endoscope except for the leading edge containing the knob. As compared to the previous embodiment where the implant was completely in front of the scope, placing the implant in this position may allow the operator a better field of view as the implant cannot be blocking the view while gaining access to the target anastomosis location. However, the disadvantage is that the implant will increase the overall profile of the endoscope making it potentially more difficult to push through narrow regions such as the pylorus or ileocecal valve. A retention feature  158  may be attached to the outside of the endoscope  132  to prevent the proximal end of the implant  136  from bending away from the endoscope during retrograde movement of the endoscope. For instance, the proximal end of the implant may catch on the vessel wall or other anatomical features during retrograde movement. Similar to the previous embodiment,  FIG. 16   b  illustrates that the implant  136  can be moved axially from the distal tip of the endoscope  132  Likewise, the endoscope is pre-assembled in similar fashion to the previous embodiment in that a delivery catheter  134  is loaded into the working channel  138  of the endoscope  132  and the magnetic implant  136  is releasably attached to the distal end of the delivery catheter  34  using a snare  142  that is wrapped around a knob feature  140  integral to the magnetic implant  36 .  FIG. 16   c  illustrates unlocking the snare wire  142  and releasing the magnetic implant  136 . 
         [0086]      FIG. 17  shows a cross section of the distal portion of the endoscopic delivery device  130  in its locked condition. Similar to the previous embodiment, the magnetic implant  136  consists of a magnet  144  and housing  146 . The housing consists of a top  148   a  and bottom  148   b.  The top  148   a  contains a knob feature  140  for holding onto the magnetic implant  136  with a snare  142 . Although an external means for releasably attaching the implant to the delivery catheter using a knob feature has been shown, an implant housing is contemplated with internal releasable attachment features. As previously described, the magnetic implant incorporates rounded atraumatic features for ease of tracking the device through the body lumen prior to coupling and after the anastomosis has been created when the implant is exiting the body. 
         [0087]      FIGS. 18   a - 18   c  show an alternative embodiment of an endoscopic delivery device  230  used according to the methods described previously to create a duodenum to transverse colon or ileum anastomosis. This embodiment is similar to the previous embodiments except that the magnetic implant geometry has changed to allow the implant to travel down the working channel of an endoscope instead of being pre-assembled at the distal end of the endoscope. One advantage of this embodiment as compared to the previous embodiments is that the endoscope may access the target anastomosis site in the duodenum and ileum or transverse colon without the potential challenges of the delivery catheter or magnetic implant extending out of the distal tip of the endoscope or to the side of the endoscope. This may allow the operator to use the endoscopes without the magnetic implant potentially obstructing the view, or adding to the effective diameter of the delivery device by the implant riding on the side of the scope, or adding to the overall stiffness of the endoscope by having a delivery catheter in the working channel and an implant leading the endoscope as the operator attempts to articulate the distal end of the scope and navigate through the vessels. Preferably, the endoscope is advanced through the vessel to the target implant location and the magnetic implant is subsequently advanced through the working channel to the distal tip of the endoscope. However advantageous it may seem to advance the delivery catheter and magnetic implant to the distal end of the endoscope after it has reached its target location as just described, the operator may pre-load the working channel with the delivery catheter and magnetic implant and advance it to the distal tip of the endoscope prior to or while tracking the endoscope through the body vessel to the target anastomosis location. Although the previously described embodiments may also work with advanced access tools, this embodiment is more readily available to be used with single of double balloon enteroscopes or other overtube or externally applied devices to a standard endoscope for gaining access deep into the small bowel from either a nasal, oral, or anal access location. 
         [0088]      FIG. 18   a  illustrates that once the endoscope is navigated to the target anastomosis location, the magnetic implant  236  has been introduced into the endoscope  232  and advanced axially within the working channel  238  to the tip of the endoscope.  FIG. 18   b  shows the implant  236  fully advanced out the endoscope  232  in a position for coupling. The implant is attached to the delivery catheter  234  by pulling a loop feature  260  attached to the implant into the lumen of the delivery catheter using a grabber  242  that resides within the lumen of the delivery catheter.  FIG. 19 . shows a detailed view of the connection of the magnetic implant  236  to the distal end of the delivery catheter  234 . The loop  260  is back-loaded into the delivery catheter  234  by inserting the loop in the U-shaped jaw of the grabber  242  and pulling the grabber and loop into the delivery catheter. The height of the u-shaped feature is approximately the same size as the inner diameter of the delivery catheter so that the loop is trapped between the u-shaped jaw and the inner wall of the catheter. After the loop is pulled into the delivery catheter, the grabber is pulled tight relative to the delivery catheter and locked in a handle set (not shown) that would be positioned at the proximal end of the delivery catheter. While pulling tight, the implant  236  is rotated so the teeth  262  on the distal end of the delivery catheter  234  mate and insert into the notch  264  on the implant. The teeth transfer torque and rotation of the delivery catheter to the implant while the grabber  242  couples the implant axially to the catheter. These features allow the implant to be advanced axially and rotated relative to the endoscope to aid with fine positioning of the implant prior to and during coupling. 
         [0089]      FIG. 18   c  shows the implant  236  released from the delivery catheter  234 . The grabber  242  is advanced distally relative to the delivery catheter so that the loop  260  is able to leave the U-shaped jaw of the grabber.  FIG. 20 . shows a detailed view of the distal end of the delivery catheter and proximal end of the magnetic implant after release. Similar to the previous embodiments after release, the grabber  242  may recapture the loop  260  if the implant  236  needs to be repositioned or removed from the body. Although an external means for releasably attaching the implant to the delivery catheter using a loop feature has been shown, an implant housing is contemplated with internal releasable attachment features. 
         [0090]      FIG. 21  shows the distal end of the endoscopic delivery device  230  in various cross sections. Section C-C shows the width of the magnets while Section D-D shows the thickness.  FIG. 22  illustrates that the magnetic implant  236  is flexible so that it may be easily tracked through a flexible endoscope  232 . The implant may consist of one magnet or several depending on the overall length of the desired implant and the flexibility needed to access the target anastomosis location. The housing  246  may be constructed of an implant grade polymer of a durometer (hardness) that allows it to bend as shown. It may be fabricated and assembled by starting with an extrusion and assembling the magnets into the extrusion, or the magnets may be insert molded. If insert molded, the polymer used should have melt temperature that does not degrade the magnetic properties of the magnet. The housing may also be fabricated out of an implant grade metal if the implant itself does not need to be flexible; however, it can be envisioned that a series of individual magnet are encapsulated in a metal housing could be attached in series with a cable, ribbon, or hitch feature coupling them all together where the ribbon or cable flexed so that the train of magnets could navigate a tortuous path. The ribbon or cable linking the series of magnets would preferably transfer rotational and axial movement from a releasably attached delivery catheter. As previously described, the implant incorporates rounded atraumatic features for ease of tracking the device into the body lumen prior to coupling and after the anastomosis has been created when the implant is exiting the body. The implant may be coated with a lubricious coating to aid in tracking down the lumen of the endoscope. Similar to the previous embodiments, the magnets are preferably neodymium rare earth magnets. The notched collar  264  and loop  260  may be insert molded into the housing or separately attached by reflowing them into the polymer of the housing or bonding them to the housing. The collar may be integrated into the housing instead of a separate component. The loop may be fabricated out of implant grade braided wire, solid wire, or nitinol wire. It may also be fabricated out of implant grade monofilament or braided polymer line. 
         [0091]      FIG. 23   a  shows an alternative attachment device for grabbing the loop  260  on the magnetic implant  236 . In this figure, a mechanically actuated jaw grabber  266  is used to grab the loop instead of the grabber  242  shown in previous figures. The grabber has a slot cut through it to accept the loop. Similarly, the grabber  266  pulls the loop into the delivery catheter  234  and the teeth  262  slide into the slot  264  on the implant to transfer the torque as previously described.  FIG. 23   b  shows the implant  236  released from the jaws of the grabber  242 . 
         [0092]      FIGS. 24   a - 24   c  show another variation of the previously described embodiment. This embodiment shows a different delivery catheter  334  with different releasable attachment features on the proximal end of the magnetic implant  336 . This is to illustrate that there are many variations on how to releasably attach a thin magnetic implant that slides down the working channel of an endoscope to a delivery catheter. Those skilled in the art will appreciate that any deviations from what is shown would be encompassed in the spirit of the present invention. The difference in this variation is that the mechanically actuated jaw  366  is permanently attached to the distal tip of the delivery catheter  334  and does not slide within the lumen of the catheter. The torque transmitting teeth  262  and slot  264  from the previous embodiment have been replaced with a slot  372  feature in the mechanically actuated jaw and a mating bar  370  feature integrated into the housing  346  of the magnetic implant  336 , respectively. The ball  368  feature integrated into the housing  346  transmits axially movement of the catheter  334  to the implant  336 .  FIG. 25  shows a detailed view of the distal tip of the catheter  334  and the proximal end of the magnetic implant  336 . The slot  372  in the mechanically actuated jaw  366  is sized to mate and transmit torque to the bar  370  in the housing of the magnetic implant  336 . The ball  368  and bar  370  may be bonded, molded, insert molded, or over molded onto the housing. Although an external means for releasably attaching the implant to the delivery catheter using a ball and bar feature have been shown, an implant housing is contemplated with internal releasable attachment features 
         [0093]    Since endoscopes have a wide range of working channel diameters. It may be advantageous to use a scope with a rather small working channel. This may translate into using a small magnetic implant that might not have enough strength to overcome the daily loads that the intestinal vessels experience from natural digestive processes and outside physical loads, therefore one magnetic implant may not give enough force or area to ideally create the desired anastomosis or maintain implant coupling due to internal or external loads. One aspect of the present invention is that multiple magnetic implants may be used to increase the strength and/or area of the anastomotic implant(s) in each vessel.  FIG. 26  shows that the magnetic implants of the previously and subsequently described embodiments and variations may incorporate a second magnetic implant deployed to the side of the first implant to increase the anastomosis area and overall force clamping the vessels together at the anastomosis site.  FIG. 27  shows a scenario where another magnetic implant  236  or  336  is stacked on top of a previously deployed magnetic implant  236  or  336  in the same vessel. This would double the force applied to create the anastomosis over the same area, therefore doubling the pressure on the trapped tissue.  FIG. 28  shows a scenario where magnetic implants  236  or  336  have been stacked to the side and on top of previously applied magnetic implants. Magnetic implants may also be stacked in line (in front or behind) so that shorter implants could be placed in line to create a longer effective implant. The figures in no way illustrate all the combinations that those skilled in the art could easily contemplate. 
         [0094]      FIGS. 29   a - 29   d  show in stepwise fashion an embodiment of an endoscopic delivery device deploying a magnetic implant from an overtube assembled to the outside of an endoscope. The endoscopic delivery device  430  consists of a magnetic implant  436  releasably attached to a delivery catheter  434  that axially and rotationally moves within a lumen in the wall of an overtube  474 . The overtube, delivery catheter, and magnetic implant assembly are back-loaded onto the endoscope  432  prior to inserting into the body. This view shows the overtube  474  in a retracted position away from the distal tip of the endoscope  432  allowing the articulating portion of the endoscope to be free from constrainment of the overtube. This feature allows the operator the ability to freely navigate through the body vessels without view obstruction of the magnetic implant  436  or hindrance of articulation of the endoscope. A grasping device  478  releasably holds the magnet in a slot  476  on the overtube  474 . The notch on the overtube provides further constrainment of the magnet, especially in transferring torque and rotation to the implant about the endoscope.  FIG. 29   b  illustrates that the overtube  474  can be moved axially in relation to the endoscope  432 . Once the operator has navigated the distal tip of the endoscope to the desired target anastomosis location, the magnetic implant  436  is advanced to the tip of the endoscope  432  by moving the overtube  474  axially as shown. The ability to rotate the overtube about the endoscope allows the operator to position the implant in any radial direction to aid in achieving magnetic coupling with another magnetic implant in an adjacent vessel.  FIG. 29   c  illustrates the delivery catheter  434  telescoping the magnetic implant  436  distal to the tip of the endoscope  432  to aid in magnetic coupling to another implant in an adjacent vessel. Also, the implant may be radially aligned by rotating the shaft of the delivery catheter.  FIG. 29   d  shows the overtube  474 , delivery catheter  434 , and mechanically actuated jaw grabber  466  after the magnetic implant  436  has been released. The mechanically actuated jaw grabber  466  is attached to the delivery catheter  434 . The delivery catheter  434  is located within a lumen  478  in the wall of the overtube  474 . The mechanically actuated grabber may be designed to releasably attach to a feature that is internal or external to the magnetic implant. As described in the previous embodiments, the delivery catheter may be coated with a lubricious coating to aid in advancing down the lumen of the overtube. The inner diameter of the overtube may be coated to aid in advancing and rotating the overtube about the endoscope. Also, the implant may be coated with a lubricious coating to aid in advancing through the body vessel. The coating may be a silicone or hydrophilic coating. 
         [0095]      FIGS. 30   a - 30   c  show in stepwise fashion an alternative embodiment of an overtube endoscopic delivery device similar to the device previously described. This embodiment shows an overtube with a slot formed in the distal tip to receive a small profile magnetic implant as previously described in  FIGS. 18-25 . The overtube also has a lumen within its wall to accept a delivery catheter as previously described. The endoscopic delivery device  530  consists of a magnetic implant  536  releasably attached to a delivery catheter  534  that axially and rotationally moves within a lumen  578  in the wall of an overtube  574 . Similar to the previous embodiment, the overtube, delivery catheter, and magnetic implant assembly are back-loaded onto the endoscope  532  prior to inserting into the body.  FIG. 30   a  shows the overtube  574  in a retracted position away from the distal tip of the endoscope  532  allowing the articulating portion of the endoscope to be free from constrainment. The overtube  574  may be designed to integrate with any endoscope; however, the endoscope is preferably a gastroscope, colonoscope, or small diameter enteroscope. The distal end of the overtube is tapered to transition to the outer diameter of the endoscope. A balloon  580  may or may not be incorporated at the tip of the overtube  574  to allow single or double enteroscopy to aid in accessing target anastomosis locations deep with the bowel. As previously described in the embodiments, features within the delivery catheter and on the magnetic implant releasably attach the implant to the delivery catheter. The delivery catheter  532  holds the implant within the slot  576  of the overtube  574 . As previously described, the slot on the overtube provides further constrainment of the magnetic implant, especially in transferring torque and rotation to the implant about the endoscope. Likewise,  FIG. 30   b  illustrates the delivery catheter  534  telescoping the magnetic implant  536  distal to the tip of the endoscope  532  to aid in magnetic coupling to another implant in an adjacent vessel. Also, the implant may be radially aligned by rotating the shaft of the delivery catheter.  FIG. 30   c  shows the delivery catheter  534  and grabber  542  after the magnetic implant  436  has been released. The delivery catheter, grabber and attachment features on the implant are for illustrative purposes as any combination of delivery catheter, grabber, and implant releasable attachment feature described in the previous embodiments may be incorporated as appropriate. 
         [0096]      FIGS. 31   a - 31   c  show in stepwise fashion a variation of the previously described embodiment as shown in  FIG. 30   a - 30   c.  The variation is different in that the slot or channel extends the entire length of the overtube instead of only at the distal tip of the overtube. Also, the channel is entirely within the wall of the lumen which allows the magnetic implant to be tracked along the entire length of the overtube. Similar to the previous embodiment, the overtube is back-loaded onto the endoscope  532  prior to inserting into the body, but the delivery catheter and magnetic implant may be loaded in the channel prior to inserting into the body. It may be easier to articulate the endoscope and navigate to the target anastomosis location without the increased stiffness of the magnetic implant and delivery catheter near the distal tip of the endoscope; therefore, it may be preferable to advance the implant and catheter after the target location is reached. However, it may not be necessary and may be preferable in some cases to telescope out of the distal tip to help introduce/guide the endoscope through the anatomy. Since the catheter and magnetic implant may be freely exchanged through the channel, the operator may deploy a second or multiple magnetic implants at the target location without removing the endoscopes from the target location.  FIG. 31   a  shows the overtube  574  in a retracted position away from the distal tip of the endoscope  532 .  FIG. 31   b  illustrates the delivery catheter  534  telescoping the magnetic implant  536  distal to the tip of the endoscope  532  through the channel  582  in the overtube  574 .  FIG. 31   c  shows the variation after the magnetic implant has been released. As described in the previous embodiments, the delivery catheter may be coated with a lubricious coating to aid in advancing down the channel of the overtube. The inner diameter of the overtube may be coated to aid in advancing and rotating the overtube about the endoscope. Also, the implant may be coated with a lubricious coating to aid in advancing through the channel of the overtube. The coating may be a silicone or hydrophilic coating. 
         [0097]    Although not preferred, another aspect of the invention for all the overtube embodiments is that the full profile of the overtube could be shorter and reside at the distal tip of the endoscope and not extend its full profile proximally out of the body. Instead, a smaller overtube profile just encompassing the delivery catheter could extend from the short, full profile section at the distal end of the endoscope proximally out of the body. Or, the overtube may only consist of a short, full profile at the distal tip of the endoscope with only the delivery catheter extending proximally out of the body. 
         [0098]    Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. For example, though the devices described herein are optimally designed for use in a probe, obviating the need for puncturing patient tissue or making incisions, one skilled in the art will appreciate that these devices could be used in surgical or laparoscopic procedures. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.