Abstract:
An intragastric balloon ( 10 ) for use in the stomach including a sealed container and separated expandable foaming substances within the sealed container, wherein the substances are adapted to expand and cure to a foam when mixed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a U.S. National Stage application of PCT/AU2013/000826 filed 24 Jul. 2013, which claims priority to Australian patent application 2012903567 filed 17 Aug. 2012, the entire disclosures of which are hereby incorporated by reference in their entireties. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention generally relates to intragastric balloons for obesity treatment. 
       BACKGROUND ART 
       [0003]    Intragastric balloons as an alternative to obesity treatment using drugs, behavior therapy, physical exercise and surgery are well known. For some time physicians have been placing intragastric balloons into the stomach reservoir to reduce the available area within the stomach and hence limit capacity for food. Once deployed in the stomach and expanded to its full size, the balloon helps to trigger a sensation of fullness and a decreased feeling of hunger. These prior art balloons are typically spherical, cylindrical or pear shaped, generally range in size from 200-700 ml or more, are made of an elastomer such as silicone, polyurethane, or latex, and are filled with air, water, or saline. 
         [0004]    These prior art balloons are often inserted into the stomach in an deflated state via endoscope or swallowing and are then inflated with gas, liquid and sometimes foam using a tube passing through the mouth and oesophagus that actively inflates or expands the balloon. Other balloons include a tube exiting the nasal passage that allows the balloon to be periodically deflated and re-inflated to better simulate normal food intake. The need to inflate and/or deflate the balloon in the stomach can cause significant discomfort to the patient. Alternatively these prior art balloons can be inserted surgically and inflated during the surgery procedure. In all these arrangements the need to seal the intragastric balloon once it has been inflated or deflated arises. 
         [0005]    With endoscopic oesophageal insertion and subsequent inflation and/or deflation or with surgical insertion there are inherent risks to the patient, some of these being perforation of the oesophagus and/or stomach, leakage or spillage of the material to be injected into the balloon and standard risks associated with anesthetic. 
         [0006]    Some prior art intragastric balloons require gastric fluid to pass through the external wall of the balloon, causing material within it to expand due to added liquid. In these prior art balloons gastric fluid is able to continuously interact with the material within the balloon. 
         [0007]    With the use of these prior art gastric balloons complications have also been observed, such as gastric ulcers, 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. 
         [0008]    The preceding discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application. 
       SUMMARY OF INVENTION 
       [0009]    The present invention seeks to provide an intragastric balloon that overcomes or ameliorates at least some of the problems referred to above, or to at least reduce the likelihood of at least one of the difficulties referred to above arising. 
         [0010]    The present invention provides a self expanding intragastric balloon for use in the stomach including a sealed container and separated expandable foaming substances within the sealed container, wherein the substances are adapted to expand and cure to a foam when mixed, and wherein the foam, when cured, substantially fills the intragastric balloon. 
         [0011]    In a second aspect of the present invention, there is provided a self expanding intragastric balloon for use in the stomach including a sealed container and separated expandable foaming substances within the sealed container, wherein the substances are adapted to expand and cure to a foam when mixed; and wherein material that the balloon is made of promotes transfer, through the material, of the gas created when the mixture expands and cures to a foam so that the foam, when cured, substantially fills the intragastric balloon. 
         [0012]    The expanding of the foam may be timed so that the substances are mixed out of the body and the intragastric balloon swallowed before the intragastric balloon is fully expanded. 
         [0013]    The intragastric balloon may be too large to pass through the pyloric sphincter once the substances are cured. 
         [0014]    The substances may be separated by a frangible membrane. 
         [0015]    The substances may be separated by a clip. 
         [0016]    Before the substances are cured the intragastric balloon may be swallowed. 
         [0017]    The volume of the intragastric balloon before the substances have expanded may be between 1 ml and 25 ml. 
         [0018]    The intragastric may be compressed prior to the substances being cured. 
         [0019]    The intragastric balloon may be compressed by folding. 
         [0020]    The intragastric balloon may be compressed by rolling. 
         [0021]    The substances may be selected from polydimethyl siloxanes, polyurethanes and poly siloxanes. 
         [0022]    The sealed container may be made from polydimethyl siloxane, polytetrafluro ethylene, poly ethylene, low density polyethylene, poly propolyene, polyester and poly amide. 
         [0023]    The intragastric balloon may include a removal device attached to the sealed container adapted to communicate the intragastric balloon with the outside environment when the intragastric balloon is passing into the stomach. 
         [0024]    The volume of the intragastric balloon after the expandable substances have cured may be between 50 ml and 700 ml. 
         [0025]    Gas transportation of gases produced within the intragastric balloon and atmospheric gases may be approximately equal. 
         [0026]    The substances may be mixed using a baffle mixer. 
         [0027]    Once the foam has cured, the intragastric balloon may be adapted to maintain its shape if punctured. 
         [0028]    In a third aspect of the present invention, there is provided a self expanding intragastric balloon for use in the stomach including a sealed container and separated expandable foaming substances within the sealed container, wherein the substances are adapted to expand and cure to a foam when mixed, and wherein there is no space between the sealed container and the foam after the foam has expanded. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]    Further features of the present invention are more fully described in the following description of several non-limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. The description will be made with reference to the accompanying drawings in which: 
           [0030]      FIG. 1  is a perspective view of an intragastric balloon according to a first embodiment of the present invention; 
           [0031]      FIG. 2  is a perspective view of an intragastric balloon according to a second embodiment of the present invention; 
           [0032]      FIG. 3   a  is a perspective view of a roller for activating the intragastric balloon of  FIG. 1  or  2 ; 
           [0033]      FIG. 3   b  is a perspective view of an alternative roller for activating the intragastric balloon of  FIG. 1  or  2 ; 
           [0034]      FIG. 4  is a perspective view of an intragastric balloon according to a third embodiment of the present invention; 
           [0035]      FIG. 5  is a perspective view of an initial form of the intragastric balloon of  FIG. 1 ,  2  or  4  before expansion; 
           [0036]      FIG. 6   a  is a side view of the intragastric balloon of  FIG. 1 ,  2  or  4  prepared for ingestion; 
           [0037]      FIG. 6   b  is an end view of the intragastric balloon of  FIG. 6   a;    
           [0038]      FIG. 7  is a cutaway view of the intragastric balloon of  FIG. 1 ,  2  or  4 ; 
           [0039]      FIG. 8  is a side view of a shape that the intragastric balloon of  FIG. 1 ,  2  or  4  can take when expanded; 
           [0040]      FIG. 9  is a side view of an alternative shape that the intragastric balloon of  FIG. 1 ,  2  or  4  can take when expanded; 
           [0041]      FIG. 10  is a side view of an alternative shape that the intragastric balloon of  FIG. 1 ,  2  or  4  can take when expanded; 
           [0042]      FIG. 11  is a perspective view of a filament attached to the intragastric balloon of  FIG. 1 ,  2  or  4 ; 
           [0043]      FIG. 12  is a perspective view of a tape attachment attached to the intragastric balloon of  FIG. 1 ,  2  or  4 ; 
           [0044]      FIG. 13  is a side view of the intragastric balloon of  FIG. 1 ,  2  or  4  held within a pouch: 
       
    
    
       [0045]    In the drawings like structures are referred to by like numerals throughout the several views. The drawings shown are not necessarily to scale, with emphasis instead generally being placed upon illustrating the principles of the present invention. 
       DESCRIPTION OF EMBODIMENTS 
       [0046]    The obesity treatment apparatus depicted in  FIG. 1-13  of the present invention comprises one or more balloons, each comprising an inert outer skin filled with a separated self foaming compound, that once activated expands to fill the void within the balloon. Once within the gastric lumen of a mammalian patient the device will reside therein and be generally unable to pass through the pylorus to enter the duodenum. As used herein, the term foam material is intended to refer to a material used to expand and occupy volume within the intragastric balloon and outer skin is the balloon material which is generally not subject to the degradative 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. However this does not necessarily mean that the foam and or skin material cannot be degraded over time. 
         [0047]      FIG. 1  depicts a first embodiment of an intragastric balloon  10  according to the present invention in its pre-expanded stage. The intragastric balloon  10  is a preformed sealed device that includes a first region  2  and a second region  3  separated by a frangible internal membrane  1 . The first and second regions  2  and  3  hold two foamable precursors that are separated by the membrane  1 . The foamable precursors can be inserted into the intragastric balloon  10  at the time of the balloons manufacture, or an alternatively be inserted after manufacture through sealable openings in the balloon body. The intragastric balloon  10  can be made of a material resistant to the effects of the gastric environment such as linear low density polyethylene, Polydimethyl siloxane, polytetrafluro ethylene, Poly ethylene, poly propylene, and poly amide. The foamable precursors can include but are not limited to foamable Polydimethyl siloxane, polyurethanes and other poly siloxanes capable of foaming. 
         [0048]    When frangible membrane  1  is broken, the two foamable precursors are mixed and the foamable precursors begin to activate and expand. On activation the precursors begin to polymerize, foam, expand and cure into a stable foam material that remains expanded within the walls of the intragastric balloon  10  when cured. The cured expanded foam substantially fills the intragastric balloon  10  so that the outer surface of the expanded foam abuts the inner wall of the intragastric balloon  10 . The stable foam material can also maintain its expanded shape if it were to be directly exposed to the gastric environment. This can ensure that if the walls of the intragastric balloon are punctured, the device will maintain its shape and will not be drawn into the pyloric sphincter. Additionally a dye agent may be included in the foamable precursors such that if the device is punctured said dyeing substance will be released from the device into the gastrointestinal tract, said dye may be selected to make noticeable changes to the colour of the patients stool, urine or sclera. Biocompatible dyes such as methylene blue are suitable for this use. If the foamable precursors are Polydimethyl siloxane the foam is formed through the simultaneous release of hydrogen gas and solidification of the Polydimethyl siloxane polymer. 
         [0049]    One possible method of activation is through the application of an external force. For example the membrane  1  can be ruptured by physical manipulation of the intragastric balloon  10 . For example, through the use of the rollers illustrated in  FIGS. 3   a  and  3   b . Alternative forms of activation can include temperature, light, PH or a combination of forms that can break the frangible membrane  1  as understood by the skilled addressee. Once activated, the intragastric balloon  10  can initially expand slowly, expanding to full size within 15 minutes. When expanded to full size, the intragastric balloon  10  will be of sufficient size to prevent it passing through the pyloric sphincter. Fully expanded the intragastric balloon  10  can have a width of at least 5 cm and an expanded volume of between 50 ml to 250 ml. 
         [0050]    In one embodiment the intragastric balloon  10  will be made of a polymer material that has flexibility, stability when immersed in acid and controlled gas transport, such as low density polyethylene. When a byproduct of the expansion of the foamable precursors is hydrogen gas the gas transportation qualities of the polymer material limit the transportation of hydrogen gas produced in the foaming process compared to that of atmospheric gases (Nitrogen, Oxygen, Water Vapour and Carbon Dioxide). By regulating the transportation of hydrogen gas to be generally evenly matched to that of atmospheric gases the pressure within the balloon remains generally constant due to the hydrogen escaping from the intragastric balloon  10  being closely matched by the atmospheric gas entering it and the balloon maintains its intended shape. 
         [0051]      FIG. 2  illustrates a similar spherical embodiment of the intragastric balloon  210  as illustrated in claim  1  using a different method to separate the foamable precursors. The foamable precursors are separated into different sections  11  and  12  and a mechanical form of separation, external clip  13 , is illustrated as separating the two or more foamable precursors. The clip  13  can have a releasable attachment mechanism at one end  14 , which once undone allows the clip  13  to be removed. Alternatively, the mechanical form of separation can be a snap seal or otherwise. 
         [0052]      FIG. 3   a  depicts a roller that may be used to activate the balloon where an internal separation device such as membrane  1  is used. The roller includes a handle  22  and roller drum  21  with a smooth roller drum surface  23 . The roller drum surface  23  can be rolled over the membrane  1  to apply the require force to rupture the membrane and allow the foamable precursors to mix and activate. 
         [0053]      FIG. 3   b  illustrates an alternative embodiment of  FIG. 3   a &#39;s roller including handle  32  and roller  31 . The roller surface  33  includes multiple groves that intersect to enhance the mixing action of the roller. 
         [0054]      FIG. 4  illustrates an alternative embodiment of the intragastric balloon  410  in its pre-activated form where a baffle mixer  48  is used. The foamable precursors are located in regions  42  and  43 , separated by an internal barrier section  44 . The barrier section  44  can be a permanent fixture or a frangible barrier. A membrane  46  or a means of external mechanical separation such as a clip or clips along line  45  is employed to keep the two or more foamable precursors separate prior to activation of the balloon. The intragastric balloon  410  can be activated by breaking the membrane  46  or removing the external mechanical separation  45 , depending on which is present. Upon activation, the two foamable precursors are forced through the baffle mixer  48  by an external force. Having passed through the baffle mixer the foamable precursors are adequately mixed and become dispersed within the main volume of the balloon  41  to activate, expand and cure into an expanded foam. 
         [0055]      FIGS. 5 ,  6   a  and  6   b  illustrate arrangements for any of the above mentioned embodiments of the intragastric balloon  510 ,  610  that facilitates passing of the pre-expanded intragastric balloon  510 ,  610  through the oesophagus. The intragastric balloon  510 ,  610  is manipulated to make a more compact shape to facilitate passage through the oesophagus. When a more compact shape is achieved the intragastric balloon  510 ,  610  can be swallowed if the compact shape is of sufficiently small size, or inserted endoscopically otherwise. To more readily enable swallowing of the intragastric balloon  510 ,  610 , the volume of the unexpanded foamable precursor within the intragastric balloon  510 ,  610  can be between 1 ml and approximately 25 ml. When endoscopic insertion is used a larger intragastric balloon  510 ,  610  can be used capable of holding larger volumes of the unexpanded foamable precursor. 
         [0056]      FIG. 5  illustrates the intragastric balloon  510  as folded along its central axis  52  to reduce the width of the intragastric balloon  510 , resulting in a more compact shape that is more readily passed through the oesophagus. Alternatively the intragastric balloon  510  can be folded in three, four or in other arrangements readily understood by the skilled addressee. 
         [0057]      FIGS. 6   a  and  6   b  illustrate the side and end views respectively of a particular arrangement of any of the embodiments of the intragastric balloons described above in a compact arrangement where the intragastric balloon is rolled along the centre axis. The side view in  FIG. 6   a  illustrates the ellipsoid shape that can be taken by the rolled balloon.  FIG. 6   b  is an end view illustrating how the balloon is rolled to achieve this shape. These are only two of many possible arrangements for making the balloon more compact and the skilled addressee would readily recognize alternative arrangements. 
         [0058]    As mentioned above, the time taken from activation of the intragastric balloon to when the intragastric balloon has fully expanded can be up to 15 minutes. Limiting the time taken for the expansion of the intragastric balloon aids in ensuring that the intragastric balloon can be swallowed or endoscopically inserted in the stomach lumen while relatively small, but will also expand quickly enough to ensure that the intragastric balloon does not pass through the pyloric sphincter into the duodenum. The speed of the intragastric balloon&#39;s expansion can be controlled through the addition of catalysts in the foamable precursor such as platinum catalysts, through controlling the temperature of the intragastric balloon so that it is chilled at the time of activation and insertion into the stomach lumen. By chilling the balloon or controlling the amount of catalyst in the foamable precursors, the rate of foam production and curing can be delayed to ease passage through the oesophagus. 
         [0059]      FIG. 7  illustrates a cut away view of the balloon in its expanded state. This embodiment of the balloon is of the spherical form  61 , furthermore the cutaway section depicts the reacted cellular foam material  62 . The reacted cellular foam material  62  is expanded such that the outer surface of the reacted cellular foam material  62  abuts the inner wall of the balloon. 
         [0060]      FIGS. 8 ,  9  and  10  illustrate some of the forms the expanded intragastric balloon  810 ,  910  and  110  can take.  FIG. 8  depicts an hourglass shape with two lobes  71  and  72 . The hour glass shape can provide stimulation to the proximal region of the stomach to induce the feeling of satiety.  FIG. 9  illustrates a pear shape  81  that can also help to stimulate the proximal region of the stomach and induce a feeling of satiety.  FIG. 10  illustrates a toroidal form  91  of the balloon designed to occupy maximum volume within the stomach lumen. 
         [0061]      FIG. 11  illustrates a spherical form of the intragastric balloon  101  incorporating an additional tab  102 . This additional tab  102  can also be attached to any of the other shapes and embodiments of the intragastric balloon discussed. The additional tab  102  can include an aperture  104 . The aperture can be used for the attachment of a filament  103 . The filament  103  can be attached to the tab  102  prior to insertion of the balloon  101  into the stomach and used in the removal of the balloon  101  if the balloon  101  becomes lodged partway down the oesophagus. The filament  103  can be manufactured from either a digestible or non-digestible material. If a digestible filament  103  is used, once the intragastric balloon  101  has been ingested the filament  103  will break down and release from the primary device. In addition to being useful for the emergency removal during the initial ingestion, the tab  102  can be used to aid in the removal of the balloon  101  after a period of time in the stomach lumen and additionally in the placement of the balloon  101  if the balloon  101  is not ingested. 
         [0062]      FIG. 12  illustrates a spherical form of the intragastric balloon  111  similar to that of  FIG. 11  with a tape like member  112  attached, used for the emergency removal of the balloon  111  if the balloon  111  becomes lodged partway down the oesophagus in the same way as the filament  103  discussed above. The tape like member  112  can be attached to any of the embodiments of the intragastric balloon discussed. The tape like member  112  can be manufactured from either a digestible or non-digestible material, the advantage of a digestible member being that once ingested it will break down and release from the primary device. 
         [0063]      FIG. 13  illustrates an embodiment of the intragastric balloon  310  prepared for ingestion. The intragastric balloon  310  when compressed through folding, rolling or otherwise may be placed in a pouch  122  to aid the passage of the balloon  310  down the oesophagus. The pouch  122  may have a lip  123  that seals the intragastric balloon  310  within the pouch  122 . The pouch  122  can be made of a digestible material and may be lubricated on its outer surface with a suitable biocompatible lubricant to aid passage of the balloon  310  down the oesophagus. 
         [0064]    Modifications and variations such as would be apparent to the skilled addressee are considered to fall within the scope of the present invention. The present invention is not to be limited in scope by any of the specific embodiments described herein. These embodiments are intended for the purpose of exemplification only. Functionally equivalent products, formulations and methods are clearly within the scope of the invention as described herein. 
         [0065]    Reference to positional descriptions, such as lower and upper, are to be taken in context of the embodiments depicted in the figures, and are not to be taken as limiting the invention to the literal interpretation of the term but rather as would be understood by the skilled addressee. 
         [0066]    Throughout this specification, unless the context requires otherwise, the word “comprise” or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.