RELATED APPLICATIONS  
       [0001]    This application claims the benefit of U.S. Provisional Application No. 60/291,790 filed May 17, 2001, and U.S. Provisional Application No. 60/360,353 filed Feb. 27, 2002, both entitled “Intragastric Device For Treating Obesity”. 
     
    
     
       TECHNICAL FIELD  
         [0002]    This invention relates to medical devices, and more particularly to obesity treatment devices that can be placed in the stomach of a patient to reduce the size of the stomach reservoir.  
         BACKGROUND OF THE INVENTION  
         [0003]    It is well known that obesity is a very difficult condition to treat. Methods of treatment are varied, and include drugs, behavior therapy, and physical exercise, or often a combinational approach involving two or more of these methods. Unfortunately, results are seldom long term, with many patients eventually returning to their original weight over time. For that reason, obesity, particularly morbid obesity, is often considered an incurable condition. More invasive approaches have been available which have yielded good results in many patients. These include surgical options such as bypass operations or gastroplasty. However, these procedures carry high risks, and are therefore not appropriate for most patients.  
           [0004]    In the early 1980s, physicians began to experiment with the placement of intragastric balloons to reduce the size of the stomach reservoir, and consequently its capacity for food. Once deployed in the stomach, the balloon helps to trigger a sensation of fullness and a decreased feeling of hunger. These balloons are typically cylindrical or pear-shaped, generally range in size from 200-500 ml or more, are made of an elastomer such as silicone, polyurethane, or latex, and are filled with air, water, or saline. While some studies demonstrated modest weight loss, the effects of these balloons often diminished after three or four weeks, possibly due to the gradual distension of the stomach or the fact that the body adjusted to the presence of the balloon. Other balloons include a tube exiting the nasal passage that allows the balloon to be periodically deflated and re-insufflated to better simulate normal food intake. However, the disadvantages of having a inflation tube exiting the nose are obvious.  
           [0005]    The experience with balloons as a method of treating obesity has provided uncertain results, and has been frequently disappointing. Some trials failed to show significant weight loss over a placebo, or were ineffective unless the balloon placement procedure was combined with a low-calorie diet. Complications have also been observed, such as gastric ulcers, especially with use of fluid-filled balloons, and small bowel obstructions caused by deflated balloons. In addition, there have been documented instances of the balloon blocking off or lodging in the opening to the duodenum, wherein the balloon may act like a ball valve to prevent the stomach contents from emptying into the intestines.  
           [0006]    Unrelated to the above-discussed methods for treating obesity, it has been observed that the ingestion of certain indigestible matter, such as fibers, hair, fuzzy materials, etc., can collect in the stomach over time, and eventually form a mass called a bezoar. In some patients, particularly children and the mentally handicapped, bezoars often result from the ingestion of plastic or synthetic materials. In many cases, bezoars can cause indigestion, stomach upset, or vomiting, especially if allowed to grow sufficiently large. It has also been documented that certain individuals having bezoars are subject to weight loss, presumably due to the decrease in the size of the stomach reservoir. Although bezoars may be removed endoscopically, especially in conjunction with a device known as a bezotome or bezotriptor, they, particularly larger ones, often require surgery.  
           [0007]    What is needed is a intragastric member that provides the potential weight loss benefits of a bezoar or intragastric balloon without the associated complications. Ideally, such a-device should be well-tolerated by the patient, effective over a long period of time, sizable for individual anatomies, and easy to place and retrieve.  
         SUMMARY OF THE INVENTION  
         [0008]    The foregoing problems are solved and a technical advance is achieved by an illustrative obesity treatment apparatus comprising at least one intragastric member or artificial bezoar made of a digestive-resistant or substantially indigestible material that is introduced into a gastric lumen of a mammal in a first configuration. The intragastric member or artificial bezoar is typically inserted into the gastric lumen in a partially compacted configuration, whereby it is then manipulated into, or allowed to assume, a second expanded configuration sufficiently large to remain within the reservoir of the stomach during normal activities and not be passed through the pylorus and into the intestines. In animals, the present invention has been found to be effective in achieving weight loss over a several month period, while being easy to place and retrieve. Another advance is that the present invention can be effective at a smaller volume within the stomach than existing intragastric members, such as balloons.  
           [0009]    In one aspect of the invention, the obesity treatment apparatus comprises a plurality of elongate plastic strips joined in the middle by a retaining mechanism, such as a nylon thread, so that the intragastric device has a shape suggestive of a butterfly or bow-tie. Alternatively, the intragastric member can comprise a folded or pleated sheet, elongated fibers or hairs, or other materials that can assume the expanded configuration while not causing trauma to the stomach wall of the patient.  
           [0010]    In another aspect of the invention, the obesity treatment apparatus comprises a plurality of intragastric members, such as the embodiments described above, which are coupled together in a set or grouping within the gastric lumen. The intragastric members are introduced individually into the gastric lumen, and then attached using a coupling mechanism, which may extend from the intragastric members themselves, or they can be introduced as a set, depending on the diameter and design used. A tether tied to the device, such a nylon thread (e.g., fishing line), can be used to assist in coupling the plurality of intragastric members together. Additional components may also be used with the coupling mechanism to facilitate placement of the set and/or separation of the individual intragastric members. For example, specially configured plastic or metal pieces can be attached to the line bundling the set of intragastric members together to enhance visibility of the line for cutting with a endoscopic scissor or scalpel, or to provide a hard surface against which the cutting instrument can be applied to more easily sever the line. Irrespective of whether the obesity treatment device includes a single intragastric member, or a coupling of intragastric members, the principal requirement is that, once in the stomach, it attains a shape and size that cannot pass through or lodge in the pyloric sphincter.  
           [0011]    In another aspect of the invention, the obesity treatment device includes a delivery system, such as one or more catheters, to place the intragastric members within the gastric lumen. In one embodiment, one or more intragastric members are mounted on a catheter or overtube and secured with cotton threads extending through the passageway of the delivery catheter via oppositely placed apertures. A metal wire or loop is then withdrawn, severing the threads and releasing the intragastric member(s) into the gastric lumen. The individual intragastric members are then coupled together by drawing them together via the attached tethering threads, then secured with a device such as a rubber patch pushed by an introduced metal tube or similar device.  
           [0012]    Other delivery systems of the present invention involve constraining the intragastric members, then releasing them in the gastric lumen. These can include pushing the intragastric member(s) from an outer delivery catheter, typically by use of pusher member within the delivery catheter passageway. Other methods include constraining the intragastric member(s) with a splittable or dissolvable film or sheath that allows that device to be deployed in a compact configuration, then allowed to expand when the outer wrapping or sheath is split by the operator, or is allowed to dissolve away over time in the stomach. In the latter example, a delivery catheter may not be necessary.  
           [0013]    While a delivery catheter or other delivery system can be used to deliver the intragastric members of the present invention, it has been shown that the intragastric members can generally be placed endoscopically or blindly by pulling them into the gastric lumen using a pair of forceps or some other retrieval grasping or device.  
           [0014]    In yet another aspect of the invention, the intragastric member can comprise a plurality of expandable members that are constrained into a first configuration for introduction into the gastric lumen, whereby the device is manipulated to allow it to assume a second, expanded configuration for residing in the stomach. One such example is an intragastric member having a plurality of strips arranged concentrically and secured at each end with a tether fixedly attached at the first end and extending through an internal portion of the device. The second end attachment is adapted to slide over the tether, and can be drawn or urged toward the first end attachment to cause the expandable members to bow outward so as to increase the overall volume of the device.  
           [0015]    In still yet another aspect of the invention, the intragastric members can be pre-coupled together with a coupling mechanism, such as a nylon fishing line, prior to introduction into the gastric lumen. Because the volume of the grouping in the stomach increases over time due to mucous accumulation or other factors, a single device having the overall size of the grouping (e.g., four devices grouped together) may not be readily removed. However, by severing the line comprising the grouping mechanism, the individual intragastric devices of the grouping can be removed one at a time by using an endoscope and retrieval device.  
           [0016]    In yet another aspect of the invention, the intragastric member can comprise a single strip of material having a series of apertures space along the length thereof, wherein the strip of material is bundled into a series of folds by passing a nylon thread through the apertures and cinching the strip of material together. The intragastric member is inserted into the gastric lumen by passing the apertures of the strip of material over a wire guide, preferably in separate bundles, until the entire strip has been accumulated and bundled together inside the gastric lumen with a nylon thread. The nylon thread can be cut to allow the bundles to separate, thereby facilitating its removal by grasping and pulling one end of the strip.  
           [0017]    It has also been contemplated that more than one grouping may be used at a time. For example, two or more independent groupings of intragastric devices floating freely in the stomach may be utilized.  
           [0018]    These and other advantages, as well as the invention itself, will become apparent in the details of construction and operation as more fully described below. Moreover, it should be appreciated that several aspects of the invention can be used with other types of intragastric devices or procedures used for the treatment of obesity. 
       
    
    
     BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS  
       [0019]    Several embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which:  
         [0020]    [0020]FIG. 1 depicts a pictorial view of an intragastric member of the present invention;  
         [0021]    [0021]FIG. 2 depicts a pictorial view of the embodiment of FIG. 1 with a delivery system;  
         [0022]    [0022]FIG. 3 depicts a sectional view of the delivery system of FIG. 2;  
         [0023]    FIGS.  4 - 5  depicts a pictorial view of a pair of intragastric members of the present invention prior to, and after being coupled together;  
         [0024]    FIGS.  6 - 7  depict detail views of different embodiments of indigestible members of intragastric members of the present invention;  
         [0025]    [0025]FIG. 8 depicts a partially sectioned side view of an expandable intragastric member of the present invention;  
         [0026]    [0026]FIG. 9 depicts a pictorial view of an intragastric member of the present invention being delivered from an outer catheter;  
         [0027]    [0027]FIG. 10 depicts a pictorial view of an intragastric member of the present invention that includes a splittable outer sheath;  
         [0028]    [0028]FIG. 11 depicts a side view of an intragastric member of the present invention encased in a dissolvable outer package;  
         [0029]    [0029]FIG. 12 depicts a pictorial view of an intragastric member of the present invention being manipulated by a endoscopic device;  
         [0030]    [0030]FIG. 13 depicts a set of intragastric members of the present invention bundled together by a coupling mechanism;  
         [0031]    [0031]FIG. 14 depicts a schematic cross-sectional view taken along line  1313  of FIG. 13;  
         [0032]    [0032]FIG. 15 depicts a pictorial view of another embodiment of an intragastric member of the present invention;  
         [0033]    [0033]FIG. 16 depicts a pictorial view of the embodiment of FIG. 15 separated into separate bundles and ready for insertion into the gastric lumen;  
         [0034]    [0034]FIG. 17 depicts a portion of the strip material that is used to form the embodiment of FIG. 15;  
         [0035]    [0035]FIG. 18 depicts the insertion of the separate bundles of FIG. 16 being inserted into the gastric lumen  
         [0036]    [0036]FIG. 19 depicts a pictorial view of yet another embodiment of an intragastric member of the present invention;  
         [0037]    [0037]FIG. 20 depicts a pictorial view of the embodiment of FIG. 19 separated into separate bundles and ready for insertion into the gastric lumen;  
         [0038]    [0038]FIG. 21 depicts a portion of the strip material that is used to form the embodiment of FIG. 19;  
         [0039]    [0039]FIG. 22 depicts the insertion of the separate bundles of FIG. 20 being nserted into the gastric lumen;  
         [0040]    [0040]FIG. 23 depicts a pictorial view of yet another embodiment of an intragastric member of the present invention; and  
         [0041]    [0041]FIGS. 24 and 25 depict an alternative method of inserting of an intragastric member of the present invention into the gastric lumen.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0042]    The obesity treatment apparatus  10  of the present invention depicted in FIGS.  1 - 25  comprises one or more intragastric members  11 , each comprising one or more digestive-resistant or indigestible member  12  sized and configured such that the intragastric member  11  can be placed into the stomach of a mammalian patient and reside therein, and being generally unable to pass through the pylorus. As used herein, the terms digestive-resistant and indigestible are intended to mean that the material used is not subject to the degrative effects of stomach acid and enzymes, or the general environment found within the gastric system over an extended period of time, therefore allowing the device to remain intact for the intended life of the device. This does not necessarily mean that the material cannot be degraded over time; however, one skilled in medical arts and gastrological devices would readily appreciate the range of material that would be suitable for use as a long-term intragastric member.  
         [0043]    Many well-known plastics have suitable properties, including selected polyesters, polyurethanes, polyethylenes, polyamides, silicone, or other possible materials. Mammalian hair has been found to form natural bezoars, and thus, is also a possible material. However, some materials, such as certain polyamides, have been found to expand over time, which can be an undesirable property. Most other natural materials are generally much less resistant to acids and enzymes, and would therefore typically require treatment or combination with resistant materials to function long term, unless a shorter-term placement is intended or desired.  
         [0044]    In the preferred embodiments, the digestive-resistant or indigestible member  12  comprises a low density polyethylene having a thickness of about 40-50 microns. Fluorinated ethylene propylene, ethylene vinyl acetate copolymer, nylon, or types of polymers that are biocompatible and to which food will generally not adhere may also be utilized.  
         [0045]    [0045]FIG. 1 depicts a single intragastric member  11  in which the digestive-resistant members  12  include a plurality of elongate plastic strips  30  that are secured together in the middle by a retaining element  34 , such as a nylon thread. The thread can be elongated to serve as a coupling mechanism  26 , such as a tether  27 . The number of digestive-resistant members  12  or strips  30  used to form the intragastric member  11  depends on the material used, their length and width, and how many intragastric members  11  comprise a set or grouping. The optimal length of the intragastric member  11  is determined by considering these same factors, as well by what is determined through experimentation to work best.  
         [0046]    Feasibility studies have been primarily limited to placement in pigs with both 8 cm and 16 cm intragastric members being used, both having a total volume of about 40 ml when placed in the stomach of the animal. Although the experiments were designed to establish the safety of the device, significant weight loss was nevertheless observed in the test animals. Although no gastric ulcers were found in animals with polyester intragastric members, there was a 20% incidence of gastric ulcers in animals having polyamide devices.  
         [0047]    Results from human trials may lead to modifications in the configuration being depicted in the figures of this application. Nevertheless, it is already understood that the dimensions shape, and construction of the intragastric member can be quite variable and still produce the desired results. For example, FIGS.  6 - 7  depict an alternative digestive-resistant member  12 . In the embodiment shown in FIG. 6, the strips  30  of FIG. 1 are replaced by digestive-resistant member  12  comprising a folded or pleated sheet  31  of plastic or other material. Either a single sheet  31  or multiple sheets can be used to form the intragastric member  11  of this embodiment. The embodiment shown in FIG. 7 depicts an intragastric member  11  in which the digestive-resistant members  12  comprise a plurality of elongated fibers or hairs  32 , typically made of polymer or other synthetic material.  
         [0048]    In the illustrative embodiments, the retaining element  34  (see FIG. 1) is located about the center of the device to hold the digestive-resistant members  12  together. However, a skilled artisan would appreciate that other designs utilizing differently placed retaining elements  34 , or eliminating them entirely, could also be utilized. For example, FIG. 8 depicts an expandable device  33  that comprises a retaining element  34  at one end to secure the digestive-resistant members  12 , which in this embodiment are typically made of a material having a certain degree of stiffness. The other end is secured by a second, slidable retaining element  41  that is disposed over a tether  27  attached to the first retaining member  34 . The intragastric member  11  is deployed in an elongated configuration with the retaining elements  34 ,  41  located near their maximum possible difference apart. After the device is placed in the gastric lumen, the slidable retaining element  41  is urged along the tether  27  and toward the first retaining element  34  by using a tube, probe, or other device, until the digestive-resistant members  12  have bowed outward, thus increasing the overall dimensions and volume of the device. The slidable retaining element  41  continues to grip the tether  27  after the urging mechanism is removed, retaining the increased dimensions of the intragastric member  11  until further manipulation is needed to reduce its diameter for removal from the patient.  
         [0049]    Deployment of intragastric member  11  can be accomplished in a number of ways, depending on the size, number, and configuration of the devices, or according to physician or patient preference. FIGS.  2 - 4  depict one such delivery system  44  in which first and second intragastric members  24 ,  25  are mounted over a plastic overtube  18  and secured by a series of suture ties  43 , such as cotton thread. A wire guide  19  is typically used in the procedure, and is placed through the passageway  52  of the overtube  18 . As shown in FIG. 3, the overtube  18  includes a plurality of apertures  21 , a pair of which (e.g., apertures  22  and  23 ) are distributed approximately every 2 cm along the distal portion of the overtube  18 . To secure the intragastric members  24 ,  25 , the suture tie is pulled through the first aperture  22  using a device  42  such as a loop, hook, snare, etc. It is fed through a releasing mechanism  20 , such as the illustrative wire loop, and then pulled through the opposite aperture  23 . The intragastric members  24 ,  25  are then placed on the overtube  18 , and the suture ties  43  are secured, thereby constraining the intragastric members into a first configuration  14  for delivery. Once the delivery system  44  has been introduced into the gastric lumen, the releasing mechanism  20  is pulled back through the overtube  18 , thereby severing the suture ties  43  one by one and releasing the intragastric members  11  into the gastric lumen where they can assume a second configuration  10  (see FIG. 1) that is sufficiently voluminous such that they cannot pass from the stomach.  
         [0050]    In order to create an obesity treatment apparatus  10  that will be retained in the stomach, it may be necessary that the intragastric members  11  be coupled together to form a grouping or set  45  of intragastric members. FIG. 4 shows the two deployed intragastric members  24 ,  25  that each have a coupling mechanism  26  (tether  27 ) attached about them such that they can be drawn together as depicted in FIG. 5. A push member  29 , such as a corrugated metal tube, is placed into gastric lumen by using an endoscope, and is guided over the tethers  27  to urge a securing element  28 , such as a rubber patch, tightly against the two intragastric members  24 ,  25 . The tethers  27  can then be cut, allowing the grouping  45  to float free within the stomach. This method can also be used to join additional intragastric members  11  to form a larger grouping  45 . Likewise, the illustrative delivery system  44  of FIG. 2 can be used to deliver any practical number of intragastric members  11 , which can then be joined in the manner described above, or they can be delivered singly or in pairs, and then grouped together after all of the intragastric members  11  have been placed.  
         [0051]    FIGS.  9 - 11  depict intragastric members  11  that are delivered into the gastric lumen within an outer member  35 , such as a sheath, tube, package, wrapping, etc., and subsequently released. For example, FIG. 9 depicts a delivery system  44  in which the intragastric member  11  (or multiple devices) is preloaded into an outer tube or introducer, then deployed therefrom by being pushed out by using a pusher member (not shown). The intragastric member  11  is shown twisted to aid in loading and deployment.  
         [0052]    [0052]FIG. 10 depicts a delivery system  44  in which the intragastric member is loaded over a tube  18  (as in FIG. 2), but is secured by an outer member  35  comprising a splittable sheath  37  or sleeve made of a thin plastic material. In the illustrative embodiment, the releasing mechanism  20  comprises a nylon thread or wire that is looped under and over the sheath  37 , such that it can be withdrawn to tear through the thin material of the sheath  37  to release the intragastric member(s)  11  mounted on the tube  18 . The releasing mechanism of FIG. 10 feeds into an aperture  21  and passageway  52  of the tube  18 , where it extends to the proximal end of the apparatus  10 . Other types of splittable sheaths  37  can also be used, such as the COOK® PEEL-AWAY Introducer Sheath.  
         [0053]    [0053]FIG. 11 depicts an intragastric member  11  that includes an outer member  35  comprising a dissolvable enclosure  38 . The material, such as cellulose, gelatin, or some other dissolvable or rapidly degrading synthetic or biomaterial material, allows the intragastric member  11  to be deployed in the first configuration  14  into the stomach, where it expands into the second configuration  15  (see, e.g., FIG. 1) once the outer enclosure  38  has dissolved or degraded away. The embodiment of FIG. 11 can be delivered with or without a catheter-based delivery system  44 , or swallowed by the patient, depending on the outer dimensions of the apparatus  10 .  
         [0054]    [0054]FIG. 12 also depicts a method of delivering the apparatus  10  of the present invention without a catheter or tube  18 . It has been found that the intragastric members  11  can be pulled into the gastric lumen using an endoscope  39  and endoscopic instrument  40 , such as a forceps, basket, snare, etc. This technique can be employed to pull groupings  45  (see, e.g., FIG. 4) of intragastric members  11  into the gastric lumen, as long as the alimentary tract is sufficiently wide to accommodate the grouping  45 .  
         [0055]    FIGS.  13 - 14  depict a grouping  45  of four intragastric members  24 , 25 ,  49 ,  50  that are pre-coupled to one another by a coupling mechanism  26  prior to introduction into the gastric lumen. Although such an arrangement or grouping  45  is sufficiently small such that it can be introduced into the gastric lumen as a set, the adherence of mucous and other changes that occur within the stomach environment can, over time, significantly increase the volume of the apparatus  10  from, for example, an original size of about 60 ml up to a possible size of about 150 ml. The increased size can make it very difficult to remove the grouping  45  from the stomach. To address this problem, multiple intragastric members  45  are grouped together for introduction, and then cut apart when it is time to remove them from the patient. The coupling mechanism  26  comprises a grouping mechanism  46 , such as a nylon thread (e.g., standard nylon fishing line), that is wrapped around the grouping  45  to pull them into close contact with one another. The grouping is released by severing the line comprising the grouping mechanism  46  and the intragastric members  24 ,  25 ,  49 ,  50  are removed one at time using a retrieval device such as that shown in FIG. 12.  
         [0056]    To assist the operator in cutting the line  46  to release the grouping  45 , two different coupling components  47 ,  48  are included in the illustrative embodiment. The first coupling component  47  comprises a curved polymer piece which is traversed by the line  46  in such a manner that the line  46  can be readily visualized under the scope, thereby providing a place to grasp and/or cut the line with an instrument extending from the endoscope. The second coupling component  48  comprises a fishing line swivel, which being metal, can be readily visualized, as well as providing a hard surface against which a cutting instrument can be applied to sever the line  46 , especially if the line has proved difficult to cut using other methods. It also provides an easily accessible point on the apparatus  10  which can be grabbed with a forceps or other device.  
         [0057]    [0057]FIG. 15 depicts another embodiment of an intragastric member  100  of the present invention. In this embodiment, the intragastric member  100  comprises a single strip of high-density polyethylene  102  that has been folded and bundled to form eighty-nine (89) loops  104  in the general shape of a butterfly. As best seen in FIG. 17, the single strip of high-density polyethylene  102  of the embodiment is formed from a tube of material having a wall thickness of 7.5 microns and a perimeter of 6 cm that has been sliced in half. Each half of the material is then folded to form a strip  102  having two walls  106 , 108 , wherein each wall  106 , 108  has a width of 1.5 cm. Of course, the strip  102  could comprise a different number of walls  106 , 108 , have a different width and thickness, or be formed from a tube of material.  
         [0058]    In the embodiment of the intragastric member  100  shown in FIG. 15, each loop  104  is 40 cm in length. Accordingly, the intragastric member  100  is formed from single strip  102  having a total length of approximately 35.6 m.  
         [0059]    The intragastric member  100  is bundled by passing a nylon thread  110  through an aperture  112  in the strip  102  at the center of the each loop  104 . As best seen in FIG. 17, the apertures  112  are formed in each wall  106 , 108  of the strip  102 , and are spaced so that loops  104  are formed 40 cm in length when adjacent apertures  112  are pulled together to form the intragastric member  100  shown in FIG. 15. In other words, the apertures  112  are located every 40 cm along the length of the strip  102 .  
         [0060]    The embodiment of the intragastric member  100  shown in FIG. 15 may be too large for delivery or insertion into the gastric lumen while in its bundled, final configuration. Accordingly, the intragastric member  100  is preferably inserted into the gastric lumen is stages. For example, and as shown in FIG. 16, the intragastric member  100  is separated into nine (9) separate bundles  114 , each of which comprise approximately ten (10) loops  104  of the strip  102 . The loops  104  of each separate bundle  114  are temporarily grouped or held together by a twist tie  116  or similar device. Grouping the separate bundles  114  in this manner improves the handling of the material and prevents the strip  102  from becoming tangled or contaminated.  
         [0061]    As shown in FIG. 18, the separate bundles  114  of the intragastric member  100  are inserted into the gastric lumen one at a time by using a wire guide  118  such as a Savary-Gilliard™ wire guide, manufactured by Wilson-Cook Medical Inc., Winston-Salem, N.C. The wire guide  118  comprises a central opening through which the nylon thread  110  passes. The end of the nylon thread  110  is connected to or tied around a small piece of nylon tubing  120  that is sized so as to not pass through the apertures  112  in the strip  102 . Prior to the insertion procedure, the nylon tubing  120  is placed near the distal (forward or insertion) end of the wire guide  118  so as to prevent the strip  102  of the first bundle  114  from sliding off the end of the wire guide  118 .  
         [0062]    Once the distal end of the wire guide  118  is positioned in the gastric lumen, the first bundle  114  is threaded over the proximal (rearward) end by passing the apertures  112  over the wire guide  118 . A plastic tube  122  is then positioned over the proximal end of the wire guide  118 , and slid towards the distal end of the wire guide  118  so as to push the folds  104  of the first bundle against the nylon tubing  120 . This procedure is then repeated by threading subsequent bundles  114  over the wire guide  118  and pushing them against the previously inserted bundles  114  until all of the bundles  114  have been inserted into the gastric lumen. The bundles  114  are then secured together by pushing a small rubber stopper or similar device  124  (see FIG. 15) along the wire guide  118  so as to press against the last bundle  114  to be inserted. The wire guide  118  is then withdrawn so as to leave the nylon thread  110  extending through the apertures  112  of all of the bundles  114 . The nylon thread  110  is then tied or otherwise secured to the stopper  124  so as to form a complete intragastric member  100  as shown in FIG. 15.  
         [0063]    To remove the intragastric member  100  from the gastric lumen, the nylon thread  110  is typically cut so as to release the folds  104 . One end of the strip  102  is then grasped by an endoscopic or similar device and pulled out of the patient.  
         [0064]    [0064]FIG. 19 depicts yet another embodiment of an intragastric member  200  of the present invention. In this embodiment, the intragastric member  200  comprises a double strip of low-density polyethylene  202  that has been folded and bundled to form approximately forty-five (45) loops  204  in the general shape of a butterfly. As best seen in FIG. 21, the double strip of low-density polyethylene  202  of this embodiment comprises a pair of strips  202  each having two walls  206 ,  208 , wherein each wall  206 ,  208  has a width of 15 mm and thickness in the range of 40-50 microns.  
         [0065]    In the embodiment of the intragastric member  200  shown in FIG. 19, each loop  204  is 20 cm in length. Accordingly, the intragastric member  200  is formed from a double strip  202  of material having a total length of approximately 18 m (i.e., each strip  202  has a total length of approximately 18 m). A double strip  202  having longer or shorter lengths may also be used depending on the desired size and mass of the intragastric member  200 .  
         [0066]    The intragastric member  200  is bundled by passing a nylon thread  210  through an aperture  212  in each strip  202  at the center of the each loop  204 . As best seen in FIG. 21, the apertures  212  are formed in each wall  206 ,  208  of each strip  202 , and are spaced so that loops  204  are formed  20  cm in length when adjacent apertures  212  are pulled together to form the intragastric member  200  shown in FIG. 19. In other words, the apertures  212  are located every 20 cm along the length of the strip  202 . In the preferred embodiment shown, apertures  212  have a diameter of approximately 3.5 mm.  
         [0067]    The embodiment of the intragastric member  200  shown in FIG. 19 may be too large for delivery or insertion into the gastric lumen while in its bundled, final configuration. Accordingly, the intragastric member  200  is preferably inserted into the gastric lumen is stages. For example, and as shown in FIG. 20, the intragastric member  200  is separated into nine (9) separate bundles  214 , each of which comprise approximately five (5) loops  204  of the strip  202 . The loops  204  of each separate bundle  214  are grouped or held together by a breakable tie  216 , made of cotton thread, or similar device. As will be explained below, grouping the separate bundles  214  in this manner improves the handling of the material and prevents the strips  202  from becoming tangled or contaminated during the insertion thereof.  
         [0068]    As shown in FIG. 22, the separate bundles  214  of the intragastric member  200  are inserted into the gastric lumen one at a time by using a wire guide  218  such as a Savary-Gilliard™ wire guide, manufactured by Wilson-Cook Medical Inc., Winston-Salem, N.C. The wire guide  218  comprises a central opening through which the nylon thread  210  passes. The end of the nylon thread  210  is connected to or tied around a small nylon disc  220  that is sized so as to not pass through the apertures  212  in the strips  202 . Prior to the insertion procedure, the nylon disc  220  is placed near the distal (forward or insertion) end of the wire guide  218  so as to prevent the strips  202  of the first bundle  214  from sliding off the end of the wire guide  218 .  
         [0069]    Once the distal end of the wire guide  218  is positioned in the gastric lumen, the first bundle  214  is threaded over the proximal (rearward) end by passing the apertures  212  over the wire guide  218 . A pusher tube  222 , which may be plastic, metal or some other suitable material, is then positioned over the proximal end of the wire guide  218 , and slid towards the distal end of the wire guide  218  so as to push the folds  204  of the first bundle  214 , which remain bundled by tie  216 , against the nylon disc  220 .  
         [0070]    In the preferred embodiment shown, one or more of the apertures  212  in each bundle  214  have an increased diameter that is sufficient to allow one more folds  204  to slide over the outside of the pusher tube  222 . This permits the portion of the strips  202  connected between adjacent bundles  214  to be guided (extended) along the wire guide  218  without interfering with the deployment of each bundle  214 . In the preferred embodiment shown, those apertures  212  having an increased diameter are approximately 9-10 mm in diameter.  
         [0071]    This procedure is then repeated by threading subsequent bundles  214  over the wire guide  218  and pushing them against the previously inserted bundles  214  until all of the bundles  214  have been inserted into the gastric lumen. The bundles  214  are then secured together by pushing a small rubber stopper or similar device  224  (see FIG. 19) along the wire guide  218  so as to press against the last bundle  214  to be inserted. The wire guide  218  is then withdrawn so as to leave the nylon thread  210  extending through the apertures  212  of all of the bundles  214 . The nylon thread  210  is then tied or otherwise secured to the stopper  224  so as to form a complete intragastric member  200  as shown in FIG. 19.  
         [0072]    To remove the intragastric member  200  from the gastric lumen, the nylon thread  210  is typically cut so as to allow the intragastric member  200  to separate in separate bundles (see FIG. 20). The separate bundles  214 , which remain connected to each other by strips  202 , can then be removed one at a time. In the event that the removal of the intragastric member  200  in separate bundles  214  becomes difficult or problematic, then breakable ties  216  may be severed to release the folds  204  of one or more of the bundles  216 .  
         [0073]    As best seen in FIG. 21, visual markers  226 , such as colored tubing, are sutured to the side of the strips  202  of the first or last fold  204  on either side of the aperture  212 . These markers  226  assist the physician in locating the nylon thread  210 , which may be difficult to identify after the device has resided within the gastric lumen for an extended period of time. Once the nylon thread  210  is cut, one end of the pair of strips  202 , or one of the bundles  216 , is then grasped by an endoscopic or similar device and pulled out of the patient.  
         [0074]    [0074]FIG. 23 depicts yet another embodiment of an intragastric member  400  of the present invention. In this embodiment, the intragastric member  400  comprises nylon thread  402  that has been tied into a series of nylon balls  404 . The nylon balls  404  are inserted into the gastric lumen separately and then connected together to form a single, larger mass of nylon thread (not shown).  
         [0075]    The above-described embodiments, particularly the embodiments of FIGS. 15 and 19, can be deployed using alternative procedures. For example, and as shown in FIGS. 24 and 25, the intragastric member  300  could be deployed by extending the strip  302  along a nylon thread  304  that has been formed into a loop  306 . Once the end  308  of the loop  306  has been inserted into the gastric lumen, then a locking device  310 , such as plastic cone (shown in detail in FIG. 25), is pushed over both strands of the nylon thread  304  so as to close the loop  306 . As the loop  306  is closed, the strip  302  is compressed so as to form an intragastric member  300  having a configuration similar to that shown in FIGS. 15 and 19. Knots  312  are included along the nylon thread  304  to provide a ratcheting action with the locking device  310 . After the intragastric member  300  has been deployed inside the gastric lumen, then the portion of the nylon thread  304  extending beyond the locking device  310  can be severed with an endoscopic scissors and removed.  
         [0076]    Alternatively, the strip  302  can be compressed by sliding a tube (not shown) along one or both halves of the loop  306 . In addition, the intragastric member  300  can be inserted in bundles (see FIGS. 16 and 20), as opposed to the insertion of a single strip  302  of material (as described above).  
         [0077]    An anchor stent (not shown) could be utilized to temporarily secure the end of the nylon thread  304  (or the end  308  of the loop  306 ) inside the gastric lumen during the insertion procedure. For example, an anchor stent enclosing a portion of the nylon thread  304  would be inserted into the pylorus and lodged therein. One end of the nylon thread  304  (or loop  306 ) enclosed within the anchor stent is then removed therefrom and pulled out of the subject. The other end of the nylon thread  304  (or loop  306 ) remains attached to the anchor stent. The intragastric device  300  can then be inserted into the gastric lumen by pushing or sliding the strip  302  (or bundles) down the nylon thread  304  (or loop  306 ), the end of which remains secured within the gastric lumen by the anchor stent. Once the insertion procedure is removed, then the anchor stent and any excess nylon thread  304  is removed.  
         [0078]    Experimental testing of the present invention has been conducted on mammals. In particular, an embodiment of an intragastric member similar to the embodiment shown in FIGS.  19 - 21  was inserted into the gastric lumens of a group of ten (10) pigs for a period of 49 days. No deaths or major complications were observed in any of the test subjects. The initial weight for the test subjects was measured to be in the range of 25.0 to 31.2 kg, with an average weight of 27.8 kg. At the end of the 49 day testing period, the weight of the test subjects was measured to be in the range of 29.5 to 39.0 kg, with an average weight of 34.5 kg. The anticipated weight for the test subjects at the end of the testing period, in view of the normal and expected growth for these animals, was 57 kg. Accordingly, the test subjects gained an average weight that was significantly less than the weight gain observed in similar animals without the intragastric member.  
         [0079]    Any other undisclosed or incidental details of the construction or composition of the various elements of the disclosed embodiment of the present invention are not believed to be critical to the achievement of the advantages of the present invention, so long as the elements possess the attributes needed for them to perform as disclosed. The selection of these and other details of construction are believed to be well within the ability of one of even rudimentary skills in this area, in view of the present disclosure. Illustrative embodiments of the present invention have been described in considerable detail for the purpose of disclosing a practical, operative structure whereby the invention may be practiced advantageously. The designs described herein are intended to be exemplary only. The novel characteristics of the invention may be incorporated in other structural forms without departing from the spirit and scope of the invention.
An apparatus and method comprising at least one intragastric member or artificial bezoar made of a digestive-resistant or substantially indigestible material that is introduced into a gastric lumen of a mammal for the treatment of obesity. The intragastric member or artificial bezoar is typically at inserted into the gastric lumen in a partially compacted configuration, whereby it is then manipulated into, or allowed to assume, a second expanded configuration sufficiently large to remain within the reservoir of the stomach during normal activities and not be passed through the pylorus into the intestines. In animals, the present invention has been found to be effective in achieving weight loss over a several month period, while being easy to place and retrieve.