Abstract:
Intragastric implant devices for obesity treatment are disclosed. The device is passive and does not autonomously change shape, but instead reacts to movement of the stomach to induce satiety. The device includes a series of connected, articulated clips that plicate the stomach wall nondestructively (no puncturing through the gastric wall) such that the overall volume of the stomach is reduced. Cam-shaped clamping surfaces prevent slippage of the stomach tissue from within the clips. Methods of implant are disclosed including delivering the device through a transoral delivery tube and advancing the device through the esophagus to be deployed within the stomach. Removal of the device occurs in the reverse.

Description:
RELATED APPLICATIONS 
       [0001]    The present application claims priority under 35 U.S.C. §119 to U.S. Provisional Application No. 61/485,009, filed May 11, 2011 and U.S. Provisional Application No. 61/394,592, filed Oct. 19, 2010. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention is directed to intragastric devices used for the treatment of obesity, and in particular to devices and systems for placement in the stomach cavity. 
       BACKGROUND OF THE INVENTION 
       [0003]    Over the last 50 years, obesity has been increasing at an alarming rate and is now recognized by leading government health authorities, such as the Centers for Disease Control (CDC) and National Institutes of Health (NIH), as a disease. In the United States alone, obesity affects more than 60 million individuals and is considered the second leading cause of preventable death. Worldwide, approximately 1.6 billion adults are overweight, and it is estimated that obesity affects at least 400 million adults. 
         [0004]    Obesity is caused by a wide range of factors including genetics, metabolic disorders, physical and psychological issues, lifestyle, and poor nutrition. Millions of obese and overweight individuals first turn to diet, fitness and medication to lose weight; however, these efforts alone are often not enough to keep weight at a level that is optimal for good health. Surgery is another increasingly viable alternative for those with a Body Mass Index (BMI) of greater than 40. In fact, the number of bariatric surgeries in the United States is projected to reach approximately 400,000 annually in 2010. 
         [0005]    Examples of surgical methods and devices used to treat obesity include the LAP-BAND® (Allergan Medical of Irvine, Calif.) gastric band and the LAP-BAND AP® (Allergan). However, surgery might not be an option for every obese individual; for certain patients, non-surgical therapies or minimal-surgery options are more effective or appropriate. 
         [0006]    Intragastric balloons are also well known in the art as a means for treating obesity. One such inflatable intragastric balloon is described in U.S. Pat. No. 5,084,061 and is commercially available as the Orbera® System from Allergan Medical of Irvine, Calif. These devices are designed to provide therapy for moderately obese individuals who need to shed pounds in preparation for surgery, or as part of a dietary or behavioral modification program. The Orbera® System intragastric balloon floats freely in the stomach cavity and takes up space to reduce the volumetric capacity therein and increase a feeling of satiety, or fullness. 
         [0007]    A space-occupying device for the stomach cavity that is fixed in relation to the stomach is seen in U.S. Pat. No. 7,214,233 to Gannoe, et al. One embodiment shown in  FIG. 5  includes a toroidal balloon inside the stomach in conjunction with a spherical balloon outside the stomach that are locked together across a gastric wall. 
         [0008]    Other methods for treating obesity include convention stomach stapling procedures which can be done surgically or laporascopically. A number of similar gastric volume reduction devices are disclosed in U.S. Pat. No. 7,510,559 to Deem, et al., which includes creating a small pouch within the stomach from an area of the interior lining thereof. The pouch can be fastened such as with staples rendering it relatively permanent, or the tissue may be excised or pressure necrosis may cause the tissue to simply fall off from the rest of interior surface and be passed normally through the rest of the patient&#39;s body. 
         [0009]    Despite many advances in the design of intragastric obesity treatment devices, there remains a need for improved devices that can be implanted for longer periods than before or otherwise address certain drawbacks of intragastric balloons and other such implants. 
       SUMMARY OF THE INVENTION 
       [0010]    The present invention addresses the above-described problems by providing passive intragastric apparatuses and methods for inducing satiety and therefore treating obesity. Such passive devices do not autonomously change shape, but instead react within the stomach to induce satiety. The devices includes members that reside within the stomach and pinch or plicate the stomach wall, thus influencing the shape of the stomach. 
         [0011]    One embodiment described herein is an intragastric obesity treatment implant comprising a gastric clip formed by a plurality of solid articulated links including two equal rows of links joined by a hinge link. Latching members are provided on the links on the free ends of the gastric clip opposite the hinge link so as to form two parallel rows joined at both ends by, respectively, the hinge link and the latching members. Each articulated link pivotally connects to an adjacent link so as to prevent relative rotation in one direction from linear alignment but permit rotation in a common plane in the other direction. Each link further includes a cam rotatably mounted therein, the cam rotating about longitudinal axes relative to the row of links that lies in the common plane, and opposed cams being configured to non-destructively clamp tissue therebetween. The implant is capable of being unfolded open about the hinge link into a substantially linear delivery configuration and being formed of a material that will resist degradation over a period of at least six months within the stomach. 
         [0012]    Desirably, each of the cams has a substantially D-shaped cross-section with a flat side facing the opposite row of links, and the flat side of each cam may have a track-like texture. Each cam may be made of an elastomeric material that is softer than the material of the remainder of the corresponding articulated link. The parallel rows of links are preferably arranged such that when the latching members are engaged opposed cam members are spaced apart a distance between about 4 and 10 mm. 
         [0013]    In one embodiment, each of the cams rotatably mounts within a housing, and each of the housings is pivotally connected to either an adjacent housing or the hinge link, and wherein the substantially linear delivery configuration defines a longitudinal direction along the series of articulated links with the axes of rotation of the cams being parallel to the longitudinal direction. Further, each housing may include a protrusion or recess on an outer side that nests within a corresponding protrusion or recess within an outer side of an adjacent housing, and wherein the adjacent housings pivot about hinge pins connecting the corresponding protrusions and recesses. Desirably, the cams face inward and the housings face outward, and the housings have smooth convex exteriors. 
         [0014]    Another aspect of the invention is an intragastric obesity treatment implant comprising a gastric clip formed by a plurality of solid articulated links including two equal rows of links joined by a hinge link. Latching members are provided on the links on the free ends of the gastric clip opposite the hinge link so as to form two parallel rows joined at both ends by, respectively, the hinge link and the latching members. Each link further includes a cam rotatably mounted therein about longitudinal axes aligned with the rows of links, and opposed cams are configured to non-destructively clamp tissue therebetween. Each of the cams has a substantially D-shaped cross-section with a flat side facing the opposite row of links. The implant is capable of being unfolded open about the hinge link into a substantially linear delivery configuration and being formed of a material that will resist degradation over a period of at least six months within the stomach. The flat side of each cam may have a track-like texture. Desirably, the parallel rows of links are arranged such that when the latching members are engaged opposed cam members are spaced apart a distance between about 4 and 10 mm. Each cam is preferably made of an elastomeric material that is softer than the material of the remainder of the corresponding articulated link. 
         [0015]    In one embodiment, each of the cams rotatably mounts within a housing, and each of the housings is pivotally connected to either an adjacent housing or the hinge link, and wherein the substantially linear delivery configuration defines a longitudinal direction along the series of articulated links with the axes of rotation of the cams being parallel to the longitudinal direction. Further, each housing may include a protrusion or recess on an outer side that nests within a corresponding protrusion or recess within an outer side of an adjacent housing, and wherein the adjacent housings pivot about hinge pins connecting the corresponding protrusions and recesses. Desirably, the cams face inward and the housings face outward, and the housings have smooth convex exteriors. 
         [0016]    A method of plicating an inner stomach wall is also disclosed. The method includes providing a gastric clip including a plurality of articulated links hingedly connected and forming two rows of the same number of links joined by a hinge link. The gastric clip includes latching members on the free ends of the two rows of links opposite the hinge link so as to form two parallel rows joined at both ends by, respectively, the hinge link and the latching members. Each link further includes a cam rotatably mounted therein about longitudinal axes aligned with the rows of links, and opposed cams being configured to non-destructively clamp tissue therebetween, the rotatably mounted cams permitting some relatively movement of stomach tissue between the two parallel rows of links. The method includes unfolding the gastric clip about the hinge link into a substantially linear delivery configuration, delivering the unfolded gastric clip transorally through a delivery tube into a patient&#39;s stomach, and expelling the gastric clip from the delivery tube. The gastric clip is then folded about the hinge link to encompass a portion of the inner stomach wall between the two rows of links, and the latching members are engaged to plicate the portion of the inner stomach wall between the two parallel rows of links. 
         [0017]    Each articulated link in the two parallel rows of links may be pivotally connected to an adjacent link so as to permit rotation in only one direction relative to the adjacent link and create two parallel jaws that won&#39;t bow apart. Preferably, each of the cams has a substantially D-shaped cross-section with a flat side facing the opposite row of links. Each of the cams may mounted for rotation within a housing such that the cams face inward and the housings face outward, and wherein the housings have smooth convex exteriors. Desirably, each cam is made of an elastomeric material that is softer than the material of the remainder of the corresponding articulated link. 
         [0018]    A further understanding of the nature and advantages of the invention will become apparent by reference to the remaining portions of the specification and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    Features and advantages of the present invention will become appreciated as the same become better understood with reference to the specification, claims, and appended drawings wherein: 
           [0020]      FIG. 1  is a perspective view of an intragastric clip for altering the size of the stomach from within, and  FIG. 1A  is a longitudinal sectional view thereof; 
           [0021]      FIG. 1B  is a perspective view of the intragastric clip of  FIG. 1  shown in an open configuration suitable for delivery to the stomach; 
           [0022]      FIG. 2  is a perspective view of an alternative intragastric clip similar to that in  FIG. 1  but longer; and 
           [0023]      FIGS. 3A-3C  illustrate cross-sectional views of the articulated gastric clip of  FIG. 1  in a folded state clamping the inside stomach walls with clamping cams alternately unengaged and engaged due to peristaltic forces. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0024]    The present invention is directed to an intragastric device that passively treats obesity by reducing space within the stomach to induce feelings of satiety. The term “passive” refers primarily to a device that cannot affect change or stimulate the stomach, but rather one that may do so as a reaction to stomach movement. 
         [0025]    A device  20  in accordance with the present invention that influences the shape of the stomach is seen in  FIGS. 1-3  and includes members that pinch or plicate the stomach wall.  FIG. 1  illustrates an articulated gastric clip  20  in a closed state. As shown, the articulated gastric clip  20  includes a series of articulated links  21  arranged in two equal rows connected by a hinge link  22 . The two links  21  opposite the hinge link  22  include either a mating hook  23  or a latch  24 . As seen in the longitudinal sectional view of  FIG. 1A , each link  21  hingedly connects to the adjacent links, or at the ends to the hinge link  22 , mating hook  23 , or mating latch  24 , via one or more lateral hinge pins  25 . The rows of links  21  extend in a longitudinal direction while the hinge pins  25  are oriented perpendicular thereto so that the various articulated elements may pivot with respect to one another in a single plane. 
         [0026]    Each link  21  pivotally connects and is nested to an adjacent link so as to prevent relative rotation in one direction from a linear alignment but permit rotation in the other direction. That is, each link  21  includes a small longitudinal protrusion  26  that nests within a similarly shaped receptacle  28  on the outside of each pair of adjacent links. The hinge pins  25  pass laterally through the nested protrusions  26  and receptacles  28  and their position permits each adjacent pair of links  21  to rotate outward, away from the opposite row of links. That is, the bodies of the links  21  contact each other on the inside thereof to prevent the opposite rotation. Only at the hinge link  22  can the rows rotate toward each other. In this way, the two rows of links  21  can be brought together to form two jaws without bowing apart. 
         [0027]    The articulated gastric clip  20  is used to plicate the stomach wall nondestructively (no puncturing through gastric wall) such that the overall volume of the stomach is reduced. The articulated gastric clip  20  may have a customizable length such that the physician may add or remove links  21 , or may select from a collection of different length clips. 
         [0028]      FIG. 1B  shows the assembly of links  21  pivoted open about the hinge link  22  to form more of an elongated chain, suitable for delivery to and removal from the stomach through a transoral tube. The pivoting of the articulated links  21  advantageously promotes easy implantation into and removal out of the patient&#39;s stomach region. In one aspect, while in an unfolded state, the articulation feature of the articulated links  21  may allow the articulated gastric clip  20  to travel flexibly through the patient&#39;s mouth, down the patient&#39;s esophagus and into the patient&#39;s stomach in a non-linear fashion, adaptable to the configuration of the patient&#39;s openings within the mouth, esophagus and stomach. 
         [0029]    With reference back to  FIGS. 1 and 1A , each of the articulated links  21  comprises a cam housing  34  and a cam  36 . The cam housings  34  desirably have smooth convex exteriors to prevent damage to internal tissue, and include the overlapped protrusions  26  and receptacles  28  in which the hinge pins  25  are journaled. Each cam housing  34  provides a recess  38  in which a cam  36  is journaled for rotation. Specifically, housing walls flanking the recess  38  provide pivot holes  40  for cam shafts  42  on which the cams  36  rotate. That is, either the cams  36  are affixed to the cam shafts  42  which rotate in the pivot holes  40 , or the cam shafts are fixed in the holes and the cams rotate thereon. Each link  21  has its own cam shaft  42  so that the links may be articulated independently, and each cam  36  rotates independently of the others. Each cam  36  includes a relatively flat clamping surface  43  that engages stomach wall tissue, and may include features to prevent slippage including (but not limited to) the track-like texture as shown in  FIG. 1 , other surface textures, surface coatings, and more aggressive cam geometries. Each cam  36  in cross-section has a rounded “D-shape” with lobes defined on both sides of the flat clamping surface  43  and a convex backside. The cams  36  can be made from materials including (but not limited to) rubbers, fluorosilicones, fluoroelastomers, thermoplastic elastomers, thermoplastics, thermosets, metals, glass, or any combinations thereof. In one embodiment, the cams  36  are made of an elastomer material that is gentle on stomach tissue and is softer than the material of the remainder of the links  21 , such as the cam housings  34 . 
         [0030]    In the embodiment illustrated in  FIG. 1  the articulated gastric clip  20  includes six articulated links  21 , three on either side of the hinge link  22  to form two opposed rows of three links. However, any even number of articulated links  21  may be used, such as six on either side of the hinge link  22  as seen in  FIG. 2 . Furthermore, multiple clips may be separately deployed within the stomach at any one time. Each gastric clip  20  desirably includes an even number of articulated links  21  so that each has a facing link when the articulated gastric clip  20  is in a folded state. That is, in the folded state, each articulated link  21  lines up across another link to enable clamping of tissue therebetween. More particularly, the cam  36  of each of the articulated links  21  faces a corresponding cam  36  of a different articulated link  21 . 
         [0031]    The separation gap G seen in  FIG. 1A  between the cams  36  of an articulation link pair is designed to clamp stomach wall tissue, and may be variable by providing a spring bias, for example. That is, for example, the cam  36  may be spring loaded within the housings  34  such as via the journal mount of the cam shafts  42 . In this way, a particular gap G may be a minimum with the springs accommodating some larger thicknesses. Preferably the pressure applied to the stomach wall tissue by the opposed rows of cams  36  is less than that which would cause necrosis, as the gastric clip  20  is intended to be non-destructive. Stomach wall thicknesses vary, and thus the gastric clip  20  may be provided in different sizes with different gaps G, not just in different lengths. A possible range of gaps G is between about 4 and 10 mm. 
         [0032]      FIG. 1  illustrates the articulated gastric clip  20  fully folded with retaining hook  23  engaged with the retaining latch  24 . In this state, the cams  36  are facing each other at their closest distance, which is sufficient to plicate an inner wall of the patient&#39;s stomach thereby causing the effective volume of the patient&#39;s stomach to be reduced. The design of the articulated gastric clip  20  is such that each articulated link  21  may rotate about 90° outward from the flat state shown in  FIG. 1A . 
         [0033]    In another aspect, as shown in  FIG. 1A , when each articulated link  21  is in a flat state and paired, facing another articulated link  21 , the retaining latch  24  may be received and engaged by the retaining hook  23  to keep the articulated gastric clip  20  in a folded state. Part of either the hook  23  or the latch  24  can be made from an elastomeric material, which will allow for some forgiveness when opening and closing the device. The clasp closure may be made from materials including (but not limited to) rubbers, fluorosilicones, fluoroelastomers, thermoplastic elastomers, thermoplastics, thermosets, metals, glass, or any combinations thereof. Unless the retaining latch  24  and the retaining hook  23  are carefully disengaged (e.g., by using a standard grabber), any outward pressure to “unfold” the articulated gastric clip  20  may only tighten the engagement between the retaining latch  24  and the retaining clip  23 . Of course, other fasteners or clasps than the hook  23  and latch  24  arrangement are contemplated, such as a barbed finger passing through an aperture, a zip-tie like closure, etc. 
         [0034]    In one aspect, the rotation of the cams  36  advantageously allow for the stomach to contract and digest food and function normally without tearing or puncturing of the inner stomach walls, while effectively reducing the volume of the stomach by not becoming disengaged completely from the inner stomach walls. 
         [0035]      FIG. 3A-3C  illustrate cross sections of the links  21  with the inner stomach of the patient engaged, and show the process by which the cam mechanism operates to hold the inner stomach of the patient in place between the cams  36  while permitting some relative movement.  FIG. 3A  shows an example of one articulated pair including two cams  36 . As described, the cams  36  are housed in cam housings  34  and each pivots about cam shaft  42 . The stomach includes a first portion  44  and a second portion  46  that have been clamped between the cams  36  to reduce the effective volume of the stomach. The configuration of  FIG. 3A  may be achieved when the articulated gastric clip  20  is in a folded state with the retaining latch  24  engaged and held by the retaining hook  23  with the stomach plicated inside the formed gap of the articulated gastric clip, and specifically when held between the facing clamping surfaces  43  of facing cams  36 . 
         [0036]    When the stomach walls move (e.g., during stomach contractions when the patient is eating), the first portion  44  and the second portion  46  may begin to shift positions. However, the cams  36  act in concert to prevent slipping. As the stomach wall is pulled through the device (in either direction), the cams will tend to rotate and resist further slippage. The cams are designed such that any rotation (clockwise or counter-clockwise) from their baseline orientation will bring the cam lobes closer and reduce the distance between the cams, effectively tightening their grip on the material being held. 
         [0037]      FIG. 3B  illustrates the first portion  44  and the second portion  46  of stomach having moved to the right in the direction of the unnumbered arrow from stomach movement. As the first portion  44  and the second portion  46  of stomach move “inwards” or in a direction effectively reducing the volume of stomach, the cams  36  pivot about cam shaft  42  as shown by rotation arrows since the cams  36  are in contact with the first and second portions  44  and  46 . Accordingly, when the lobes of cams  36  come into very close proximity with each other as shown, the first and second portions  44  and  46  of the stomach are prevented from further movement in that same direction. At this position, the first portion  44  and the second portion  46  of stomach may remain stationary or shift in the opposite direction, “outward” or in a direction effectively increasing the volume of the stomach. 
         [0038]      FIG. 3C  illustrates an “outward” direction of the shift (as shown by the unnumbered arrow to the left) of the first portion  44  and the second portion  46  of stomach. As the first portion  44  and the second portion  46  of stomach move “outwards” or in a direction effectively increasing the volume of stomach, the cams  36  pivot in the other direction about cam shaft  42  as indicated. Accordingly, when the other lobes of cams  36  (as compared to  FIG. 3B ) come into very close proximity with each other as shown, the first and second portions  44 ,  46  of the stomach are prevented from further movement in that same “outward” direction. 
         [0039]    As shown by  FIG. 3A-3C , the cams  36  may rotate freely in between the positions shown in  FIG. 3B  and  FIG. 3C  in response to the shifting of the plicated portion of the inner stomach walls. However, regardless of the position of the cams  36 , the inner stomach walls are always held between them in a non-destructive manner. In this way, the articulated gastric clip  20  remains engaged with the inner stomach walls when in a folded position, plicating the stomach walls. 
         [0040]    As mentioned, the links  21  may articulate about their pin connections by at least 90°. This facilitates insertion and removal procedures. The linkages can be rigid or semi-rigid and range in length from 5 mm to 40 mm, and may be manufactured from materials including (but not limited to) rubbers, fluorosilicones, fluoroelastomers, thermoplastic elastomers, thermoplastics, thermosets, metals, glass, or any combinations thereof. The materials discussed herein advantageously allow the cams  36  to withstand the acidic environment of the patient&#39;s stomach for at least six months, and preferably more than 1 year. 
         [0041]    Although the invention has been described and illustrated with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example, and that numerous changes in the combination and arrangement of parts can be resorted to by those skilled in the art without departing from the scope of the invention, as hereinafter claimed.