Abstract:
An apparatus may be used after a surgical procedure to protect against leaks and to separate healing tissue from foreign materials such as nutritional contents. In some cases the apparatus may be easily delivered to a surgical site before, during or after a surgical procedure such as gastric bypass surgery, but this is only an example. The apparatus may include expandable anchors at either end and a collapsible central portion extending between the two expandable anchors.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Application No. 62/336,105, filed May 13, 2016, the entire disclosure of which is herein incorporated by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The disclosure is directed to devices for protecting portions of the gastrointestinal tract. More particularly, the disclosure is directed to devices that are configured to extend through the stomach and protect against leaks subsequent to bariatric procedures. 
       BACKGROUND 
       [0003]    Wounds may develop within the gastrointestinal system for a variety of reasons. For example, bariatric surgical procedures create staple lines that may be prone to leakage. In some cases, the presence of materials such as nutritional contents can interfere with healing of the staple lines. In some instances, the presence of nutritional contents can irritate healing tissue and can lead to infection. It may be helpful to protect the healing staple line from materials such as nutritional contents. Of the known medical devices and methods, each has certain advantages and disadvantages. There is an ongoing need to provide alternative medical devices as well as alternative methods for manufacturing and using medical devices. 
       SUMMARY 
       [0004]    The disclosure is directed to several alternative designs, materials and methods of manufacturing medical device structures and assemblies, and uses thereof. For example, the disclosure is directed to an apparatus that can be used after a surgical procedure to protect against leaks and to separate healing tissue from foreign materials such as nutritional contents. In some cases the apparatus may be easily delivered to a surgical site before, during or after a surgical procedure such as gastric bypass surgery, but this is only an example. 
         [0005]    An apparatus for protecting against leaks after a surgical procedure on a stomach is disclosed. The apparatus is configured to extend through the stomach once implanted and includes an elongate collapsible tubular member having a proximal region and a distal region and a collapsible lumen extending therethrough. An expandable proximal anchor is secured to the proximal region of the elongate collapsible tubular member and is configured to anchor at a first position above the lower esophageal sphincter. An expandable distal anchor is secured to the distal region of the elongate collapsible tubular member and is configured to anchor at a second position below the pylorus sphincter. The elongate collapsible tubular member, once implanted, extends through the lower esophageal sphincter such that the lower esophageal sphincter can close the elongate collapsible tubular member proximate the lower esophageal sphincter by collapsing the collapsible lumen. The elongate collapsible tubular member extends through the pylorus sphincter such that the pylorus sphincter can close the elongate collapsible tubular member proximate the pylorus sphincter by collapsing the collapsible lumen. 
         [0006]    Alternatively or additionally to any of the embodiments above, the expandable proximal anchor includes a braided stent and a covering disposed over at least part of the braided stent. 
         [0007]    Alternatively or additionally to any of the embodiments above, the expandable distal anchor includes a braided stent and a covering disposed over at least a part of the braided stent. 
         [0008]    Alternatively or additionally to any of the embodiments above, the apparatus further includes a removal tether extending around a circumference of the expandable proximal anchor. 
         [0009]    Alternatively or additionally to any of the embodiments above, the apparatus further includes a removal tether extending around a circumference of the expandable distal anchor. 
         [0010]    Alternatively or additionally to any of the embodiments above, the apparatus is bio-absorbable. 
         [0011]    Alternatively or additionally to any of the embodiments above, the apparatus further includes a wire support extending at least partially along the elongate collapsible tubular member. 
         [0012]    Alternatively or additionally to any of the embodiments above, the wire support extends from the expandable proximal anchor to the expandable distal anchor. 
         [0013]    Alternatively or additionally to any of the embodiments above, the wire support is embedded in the elongate collapsible tubular member. 
         [0014]    Alternatively or additionally to any of the embodiments above, the wire support extends helically along the elongate collapsible tubular member. 
         [0015]    Alternatively or additionally to any of the embodiments above, the elongate collapsible tubular member is formed of a polymer having a Shore durometer hardness of less than 60 A. 
         [0016]    Alternatively or additionally to any of the embodiments above, the expandable proximal anchor and the expandable distal anchor each include a wider tissue engagement portion and a narrower portion configured for securement to the elongate collapsible tubular member. 
         [0017]    An apparatus for protecting against leaks within a portion of a patient&#39;s gastrointestinal tract is disclosed. The gastrointestinal tract includes a sphincter that is configured to reversibly close the gastrointestinal tract proximate the sphincter. The apparatus includes an elongate collapsible tubular member having a first end and a second end and a collapsible lumen extending therethrough. A first anchor is secured near the first end of the elongate collapsible tubular member and is configured to anchor at a position upstream from the sphincter. A second anchor is secured near the second end of the elongate collapsible tubular member and is configured to anchor at a position downstream from the sphincter. The elongate collapsible tubular member extends through the sphincter such that the sphincter can close the elongate collapsible tubular member proximate the sphincter by collapsing the collapsible lumen. 
         [0018]    Alternatively or additionally to any of the embodiments above, the sphincter is a lower esophageal sphincter, and the first anchor is configured to be positioned upstream of the lower esophageal sphincter and the second anchor is configured to be positioned downstream of the lower esophageal sphincter such that the elongate collapsible tubular member extends through the lower esophageal sphincter. 
         [0019]    Alternatively or additionally to any of the embodiments above, the sphincter is a pylorus sphincter, and the first anchor is configured to be positioned upstream of the pylorus sphincter and the second anchor is configured to be positioned downstream of the pylorus sphincter such that the elongate collapsible tubular member extends through the pylorus sphincter. 
         [0020]    Alternatively or additionally to any of the embodiments above, the first anchor is self-expandable from a collapsed delivery configuration to an expanded anchoring configuration. 
         [0021]    Alternatively or additionally to any of the embodiments above, the second anchor is self-expandable from a collapsed delivery configuration to an expanded anchoring configuration. 
         [0022]    Alternatively or additionally to any of the embodiments above, the elongate collapsible tubular member is biased to a collapsed configuration in which a lumen extending through the elongate collapsible tubular member is closed. 
         [0023]    An apparatus for protecting against leaks within a portion of a patient&#39;s gastrointestinal tract is disclosed. The gastrointestinal tract includes a sphincter that is configured to reversibly close the gastrointestinal tract proximate the sphincter. The apparatus has an upstream end and a downstream end. An upstream anchor is disposed relative to the upstream end of the apparatus and configured to anchor at a position upstream from the sphincter. A downstream anchor is disposed relative to the downstream end of the apparatus and is configured to anchor at a position downstream from the sphincter. An elongate collapsible tubular member extends from the upstream anchor to the downstream anchor and thus extends through the sphincter. The elongate collapsible tubular member includes a collapsible lumen extending therethrough such that the sphincter can close the elongate collapsible tubular member proximate the sphincter by collapsing the collapsible lumen. 
         [0024]    Alternatively or additionally to any of the embodiments above, the elongate collapsible tubular member includes a silicone tube. 
         [0025]    The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The Figures, and Detailed Description, which follow, more particularly exemplify these embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0026]    The disclosure may be more completely understood in consideration of the following description of in connection with the accompanying drawings, in which: 
           [0027]      FIG. 1  is a schematic illustration of a portion of a person&#39;s gastrointestinal tract; 
           [0028]      FIG. 2  is a schematic illustration of a gastric sleeve procedure; 
           [0029]      FIG. 3  is a schematic illustration of an apparatus that may be used in conjuncture with a procedure such as that shown in  FIG. 2 ; 
           [0030]      FIG. 4  is a schematic illustration of the apparatus of  FIG. 3 , including a polymeric covering disposed over the anchor structures; 
           [0031]      FIG. 5  is a schematic illustration of the apparatus of  FIG. 3 , shown in a collapsed configuration; 
           [0032]      FIG. 6  is a schematic illustration of the apparatus of  FIG. 3 , shown in an axially collapsed configuration such as may be used for delivery; 
           [0033]      FIG. 7  is a schematic illustration of the apparatus of  FIG. 3 , including a wire support member; 
           [0034]      FIG. 8  is a schematic illustration of the apparatus of  FIG. 3 , including a wire support member; 
           [0035]      FIG. 9  is a schematic illustration of the apparatus of  FIG. 3 , including retrieval tethers; 
           [0036]      FIG. 10  is a schematic illustration of the apparatus of  FIG. 3 , shown disposed within a portion of the person&#39;s gastrointestinal tract with the lower esophageal and pylorus sphincters in relaxed configurations; and 
           [0037]      FIG. 11  is a schematic illustration of the apparatus of  FIG. 3 , shown disposed within a portion of the person&#39;s gastrointestinal tract with the lower esophageal and pylorus sphincters in constricted configurations. 
       
    
    
       [0038]    While the disclosure is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure. 
       DESCRIPTION 
       [0039]    For the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification. 
         [0040]    Definitions of certain terms are provided below and shall be applied, unless a different definition is given in the claims or elsewhere in this specification. 
         [0041]    All numeric values are herein assumed to be modified by the term “about”, whether or not explicitly indicated. The term “about” generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (i.e., having the same function or result). In many instances, the term “about” may be indicative as including numbers that are rounded to the nearest significant figure. 
         [0042]    The recitation of numerical ranges by endpoints includes all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). 
         [0043]    Although some suitable dimensions, ranges and/or values pertaining to various components, features and/or specifications are disclosed, one of skill in the art, incited by the present disclosure, would understand desired dimensions, ranges and/or values may deviate from those expressly disclosed. 
         [0044]    As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include or otherwise refer to singular as well as plural referents, unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed to include “and/or,” unless the content clearly dictates otherwise. 
         [0045]    The following detailed description should be read with reference to the drawings in which similar elements in different drawings are numbered the same. The detailed description and the drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the disclosure. The illustrative embodiments depicted are intended only as exemplary. Selected features of any illustrative embodiment may be incorporated into an additional embodiment unless clearly stated to the contrary. 
         [0046]    There are a number of conditions, diseases and surgical interventions that may result in wounds such as an abscess within the gastrointestinal tract. In many cases, a surgical intervention may create a staple line or suture line within a portion of the gastrointestinal tract. An illustrative but non-limiting example of such a surgical intervention is bariatric surgery. In bariatric surgery, which may be performed as an open surgery or more commonly as a laproscopic surgery, an obese patient&#39;s stomach is made substantially smaller. As a result, the patient may be able to lose weight, particularly if they follow corresponding dietary restrictions. There are several common bariatric techniques, including but not limited to a sleeve gastrectomy and a Roux-en-Y gastric bypass procedure. 
         [0047]      FIG. 1  provides an illustration of a patient&#39;s stomach  10 . The stomach  10  extends distally from an esophagus  24  to a small intestine  16  via a pylorus  14 . It will be appreciated that the stomach  10 , the esophagus  24  and the small intestine  16  may be considered as forming a portion of the patient&#39;s gastrointestinal (GI) tract. The esophagus  24  includes a lower esophageal sphincter  26 , which is shown schematically. The lower esophageal sphincter  26  is a ring of muscles that can be relaxed to provide an opening therethrough and that can be tightened to close against the flow of materials. Control of the lower esophageal sphincter  24  is largely involuntary. When the person is not eating or drinking, the lower esophageal sphincter  26  is generally closed to prevent stomach contents, including gastric acid, from moving upward into the esophagus  24  where it can cause damage. As the person swallows, the lower esophageal sphincter  26  can temporarily relax, or open, to allow swallowed nutritional content such as food and beverages, to pass into the stomach  10 . A pylorus sphincter  28  is located near the entrance to the pylorus  14 . The pylorus sphincter  28  is also a ring of muscles that can be relaxed to provide an opening therethrough and that can be tightened to close against the flow of materials. The pylorus sphincter  28  may be opened and closed to control the passage of stomach contents from the stomach  10  to the small intestine  16 . Control of the pylorus sphincter  28  is largely involuntary. 
         [0048]      FIG. 2  illustrates the results of a procedure known as sleeve gastrectomy, in which a large portion of the patient&#39;s stomach  10  is cut away. As a result, a relatively small attached portion  12  of the patient&#39;s stomach  10  remains fluidly coupled through the pylorus  14  with the small intestine  16 . As can be seen in  FIG. 1 , a relatively large resected portion  18  of the patient&#39;s stomach  10  is resected, or cut away from the attached portion  12  of the stomach  10  that remains as part of the patient&#39;s effective gastrointestinal tract and extends from the esophagus  24  to the small intestine  16 . It will be appreciated that as a result of the resection, a large staple line  20  is formed along one side of the small portion  12  of the stomach  10 . A corresponding long staple line  22  is formed along one side of the resected portion  16  of the stomach  10 . The disclosure provides devices that may, for example, be used to isolate the staple line  20  from nutritional contents passing through the attached portion  12  of the stomach  10 . 
         [0049]      FIG. 3  is a schematic illustration of an apparatus  30  that may, for example, be considered as being useful for protecting against leaks after a surgical procedure on the stomach  10 , such as but not limited to the gastric bypass procedure illustrated in  FIG. 2 . The apparatus  30  may include an elongate collapsible tubular member  32  defining a collapsible lumen  34  that extends through the elongate collapsible tubular member  32  from a proximal region  36  to a distal region  38 . 
         [0050]    The apparatus  30  may include an expandable proximal anchor  40  that is secured to the proximal region  36  of the elongate collapsible tubular member  32 . The expandable proximal anchor  40  may, as illustrated in  FIG. 3 , be considered as being in its radially expanded configuration. As with most stent and stent-like structures, the expandable proximal anchor  40  may be constricted or otherwise radially compressed for delivery. In some cases, the expandable proximal anchor  40  may be configured to anchor at a first position above the lower esophageal sphincter  26  ( FIG. 1 ). For example, the expandable proximal anchor  40  may have an overall dimension that provides a sufficient radial force to hold the expandable proximal anchor  40  in position. 
         [0051]    The apparatus  30  may include an expandable distal anchor  42  that is secured to the distal region  38  of the elongate collapsible tubular member  32 . The expandable distal anchor  42  may, as illustrated in  FIG. 3 , be considered as being in its radially expanded configuration. As with most stent and stent-like structures, the expandable distal anchor  42  may be constricted or otherwise radially compressed for delivery. In some cases, the expandable distal anchor  42  may be configured to anchor at a second position below the pylorus sphincter  28  ( FIG. 1 ). For example, the expandable distal anchor  42  may have an overall dimension that provides a sufficient radial force to hold the expandable distal anchor  42  in position. 
         [0052]    While the expandable proximal anchor  40  and the expandable distal anchor  42  are illustrated as being roughly the same size, it will be appreciated that in some cases the relative sizes of the expandable proximal anchor  40  and/or the expandable distal anchor  42  may be varied in order to accommodate particular features of the patient&#39;s anatomy. In some cases, the expandable proximal anchor  40  may have an overall diameter, when expanded, that is in the range of 20 millimeters (mm) to 35 millimeters (mm), 23 millimeters (mm) to 33 mm, or 25 millimeters (mm) to 30 millimeters (mm), for example. In some cases, the expandable distal anchor  42  may have an overall diameter, when expanded, that is in the range 20 millimeters (mm) to 35 millimeters (mm), 22 millimeters (mm) to 32 mm, or 25 millimeters (mm) to 30 millimeters (mm), for example. In some embodiments the diameter of the proximal anchor  40  in its expanded state may be greater than the diameter of the distal anchor  42  in its expanded state to accommodate the patient&#39;s anatomy. 
         [0053]    In some cases, as illustrated, the expandable proximal anchor  40  may include a wider tissue engagement portion  44  that is configured to engage tissue and a narrower portion  46  that is configured to engage the proximal region  36  of the elongate collapsible tubular member  32 . In some cases, for example, the elongate collapsible tubular member  32  may be secured to the expandable proximal anchor  40  by stretching the proximal region  36  of the elongate collapsible tubular member  32  over the narrower portion  46 . In some cases, an adhesive may also be used to secure the elongate collapsible tubular member  32  to the expandable proximal anchor  40 . 
         [0054]    In some cases, as illustrated, the expandable distal anchor  42  may include a wider tissue engagement portion  48  that is configured to engage tissue and a narrower portion  50  that is configured to engage the distal region  38  of the elongate collapsible tubular member  32 . In some cases, for example, the elongate collapsible tubular member  32  may be secured to the expandable distal anchor  42  by stretching the distal region  38  of the elongate collapsible tubular member  32  over the narrower portion  50 . In some cases, an adhesive may also be used to secure the elongate collapsible tubular member  32  to the expandable distal anchor  42 . 
         [0055]    In some cases, the expandable proximal anchor  40  and the expandable distal anchor  42  may be considered as being stents and may be formed of any desired metallic or polymeric material. In some cases, the expandable proximal anchor  40  and the expandable distal anchor  42  may be formed of a bioabsorbable material that will simply disappear in time within the body. As illustrated, the expandable proximal anchor  40  and the expandable distal anchor  42  are braided stents. In some cases, the expandable proximal anchor  40  and/or the expandable distal anchor  42  may be woven stents or laser cut stents. 
         [0056]    In some cases, and with brief reference to  FIG. 4 , the expandable proximal anchor  40  may include a polymeric covering  60  that covers at least part of or the entire circumference of the expandable proximal anchor  40 . In some cases, the expandable distal anchor  42  may similarly include a polymeric covering  62  that covers at least part of or the entire circumference of the expandable distal anchor  42 . In some cases, the coverings  60 ,  62  may be formed of a low durometer silicone or polyurethane, for example. For instance, the coverings  60 ,  62  may be formed of a polymeric material having a Shore durometer hardness reading of 60 A or less, 50 A or less, 40 A or less, 30 A or less, or 20 A or less in some embodiments. 
         [0057]    Returning to  FIG. 3 , the elongate collapsible tubular member  32  may have an overall length that is sufficient to place the expandable proximal anchor  40  above a sphincter such as but not limited to the lower esophageal sphincter  26  ( FIG. 1 ) and to place the expandable distal anchor  42  below a sphincter such as but not limited to the pylorus sphincter  28  ( FIG. 1 ). In some cases, the elongate collapsible tubular member  32  may have a length that is in the range of 15 centimeters (cm) to 25 cm. The apparatus  30  may have an overall length that is that is in the range of 25 cm to 35 cm. The elongate tubular member  32  may have a diameter (when not collapsed) of 20 millimeters (mm) to 30 millimeters, for example. 
         [0058]    In some cases, as shown for example in  FIG. 5 , the elongate collapsible tubular member  32  may be considered as being biased to a collapsed configuration. In some cases, the elongate collapsible tubular member  32  may be considered as collapsing under its own weight, thereby causing the collapsible lumen  34  ( FIG. 3 ) to close itself off whenever there is no nutritional contents moving down through the collapsible lumen  34 . The elongate collapsible tubular member  32  may be formed of a polymeric material having a Shore durometer hardness reading of 60 A or less, 50 A or less, 40 A or less, 30 A or less, or 20 A or less in some instances. In some cases, the elongate collapsible tubular member  32  may be formed of silicone or polyurethane, although other polymers are contemplated. In some cases, the elongate collapsible tubular member  32  may be formed of a bioabsorbable material that will simply disappear over time in the body. In some instances, the elongate collapsible tubular member  32 , along with the proximal and distal anchors  40 ,  42 , may be formed of a bioabsorbable material, however, in other instances the elongate collapsible tubular member  32  may be formed of a bioabsorbable material while the proximal and distal anchors  40 ,  42  may be formed of a biostable material. Thus, after the elongate collapsible tubular member  32  has been fully absorbed by the patient&#39;s body, the proximal and/or distal anchors  40 ,  42  may be removed from the patient&#39;s body, if desired. 
         [0059]    In some instances, as shown for example in  FIG. 6 , the apparatus  30  may be axially compressible or collapsible. As shown, the expandable proximal anchor  40  is quite close to the expandable distal anchor  42 , and the elongate collapsible tubular member  32  is folded up accordion-style between the expandable proximal anchor  40  and the expandable distal anchor  42 . In some cases, this configuration may be useful in delivering the apparatus  30  via a catheter extended through an endoscope. The catheter may be advanced into position proximate the pylorus sphincter  28  ( FIG. 1 ), such as distal of the pylorus sphincter  28 , for example, and an outer sheath may be withdrawn proximally to allow the expandable distal anchor  42  to expand and engage tissue distal of the pylorus sphincter  28 . The catheter may then be withdrawn proximally until the expandable proximal anchor  40  is positioned proximate the lower esophageal sphincter  26  ( FIG. 1 ), such as proximal of the lower esophageal sphincter  26 , for example, and the outer sheath may be withdrawn proximally to allow the expandable proximal anchor  40  to expand and engage tissue proximal of the lower esophageal sphincter  26 . It will be appreciated that this particular delivery technique is merely illustrative. 
         [0060]    In some cases, there may be a desire to provide some structure to the elongate collapsible tubular member  32 .  FIGS. 7 and 8  provide illustrative, but non-limiting examples of wire supports that may be incorporated into the elongate collapsible tubular member  32  of the apparatus  30 . In  FIG. 7 , several axially-aligned wire supports  64  extend longitudinally along the length of the elongate collapsible tubular member  32  from the expandable proximal anchor  40  to the expandable distal anchor  42 . In  FIG. 8 , several helically aligned wire supports  66  are shown extending helically along the length of the elongate collapsible tubular member  32  from the expandable proximal anchor  40  to the expandable distal anchor  42 . In some cases, the wire supports  64  and/or the wire supports  66  are disposed inside the collapsible lumen  34  ( FIG. 3 ) (i.e., along an inner surface of the polymer wall forming the elongate collapsible tubular member  32 ) or are embedded within the polymer wall forming the elongate collapsible tubular member  32 , and thus are shown in phantom. In some cases, the wire supports  64  and/or the wire supports  66 , if present, are configured to hold the collapsible lumen  34  open in the absence of externally applied forces, but are compliant enough that the collapsible lumen  34  is able to close in response to the lower esophageal sphincter  26  ( FIG. 1 ) and/or the pylorus sphincter  28  ( FIG. 1 ) constricting against the apparatus  30 . 
         [0061]    In some cases, as shown for example in  FIG. 9 , the apparatus  30  may include features that enable re-positioning during deployment and/or that facilitate subsequent removal of the apparatus  30 . In some cases, for example, the expandable proximal anchor  40  may include a tether  70  that extends around a circumference of the expandable proximal anchor  40 . For example, the tether  70  may be a suture extending circumferentially around the proximal end of the expandable proximal anchor  40  configured to be grasped and pulled proximally to remove the expandable proximal anchor  40  from the patient. In some instances, the tether  70  may be woven through interstices of a woven structure of the expandable proximal anchor  40 . In other instances, the tether  70  may be formed as a unitary portion of a filament forming the expandable proximal anchor  40 . By providing a constricting force on the tether  70 , it is possible to partially compress the expandable proximal anchor  40  for removal from the body lumen. Similarly, the expandable distal anchor  42  may include a tether  72  that extends around a circumference of the expandable distal anchor  42 . For example, the tether  72  may be a suture extending circumferentially around the proximal end of the expandable distal anchor  42  configured to be grasped and pulled proximally to remove the expandable distal anchor  42  from the patient. In some instances, the tether  72  may be woven through interstices of a woven structure of the expandable distal anchor  42 . In other instances, the tether  72  may be formed as a unitary portion of a filament forming the expandable distal anchor  42 . By providing a constricting force on the tether  72 , it is possible to partially compress the expandable distal anchor  42 . In some instances, the tether  70  may be interconnected with the tether  72  such that pulling the tether  70  proximally simultaneously pulls the tether  72  to simultaneously collapse both the proximal expandable anchor  40  and the expandable distal anchor  42 . For example, a tether  74  may extend longitudinally through the elongate collapsible tubular member  32 , such as through the lumen  34 , from the tether  70  to the tether  72 . Thus, pulling the tether  70  proximally will likewise pull the longitudinally oriented tether  74  proximally within the collapsible tubular member  32  to in turn pull the tether  72  proximally to collapse the proximal and distal anchors  40 ,  42  simultaneously. 
         [0062]    It will be appreciated that features shown in one Figure may be combined with features shown in other Figures. For example, the polymeric coverings  60 ,  62  shown in  FIG. 4  may be combined with the tethers  70 ,  72  shown in  FIG. 9 . The wire supports  64  ( FIG. 7 ) and/or the wire supports  66  ( FIG. 8 ) may be combined with the tethers  70 ,  72  of  FIG. 9  or with the polymeric coverings  60 ,  62  of  FIG. 4 . 
         [0063]      FIGS. 10 and 11  show the apparatus  30  disposed within the gastrointestinal tract, extending through the remaining stomach portion  12  with the expandable proximal anchor  40  disposed above (or upstream of) the lower esophageal sphincter  26  and the expandable distal anchor  42  disposed below (or downstream of) the pylorus sphincter  28 . In  FIG. 10 , the elongate collapsible tubular member  32  is shown in a non-collapsed configuration with the lower esophageal sphincter  26  and the pylorus sphincter  28  both in their relaxed, or open configurations. In  FIG. 11 , both sphincters  26 ,  28  are in their constricted, or closed configurations, and the elongate collapsible tubular member  32  is shown in a collapsed configuration. While the sphincters  26 ,  28  are shown as either both open or both closed, it will be appreciated that in many cases these sphincters  26 ,  28  will open and close independently of each other. 
         [0064]    It will be appreciated that a variety of different materials may be used in forming the apparatus  30 . In some embodiments, for example, the polymeric covering  60 ,  62  may include any suitable polymeric material, including biocompatible materials such as polyurethane or silicone. Other suitable polymers include but are not limited to polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, for example, DELRIN® available from DuPont), polyether block ester, polyurethane (for example, Polyurethane 85 A), polypropylene (PP), polyvinylchloride (PVC), polyether-ester (for example, ARNITEL® available from DSM Engineering Plastics), ether or ester based copolymers (for example, butylene/poly(alkylene ether) phthalate and/or other polyester elastomers such as HYTREL® available from DuPont), polyamide (for example, DURETHAN® available from Bayer or CRISTAMID® available from Elf Atochem), elastomeric polyamides, block polyamide/ethers, polyether block amide (PEBA, for example available under the trade name PEBAX®), ethylene vinyl acetate copolymers (EVA), silicones, polyethylene (PE), Marlex high-density polyethylene, Marlex low-density polyethylene, linear low density polyethylene (for example REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), poly paraphenylene terephthalamide (for example, KEVLAR®), polysulfone, nylon, nylon-12 (such as GRILAMID® available from EMS American Grilon), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (for example, SIBS and/or SIBS 50 A), polycarbonates, ionomers, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers thereof, polymer/metal composites, and the like. 
         [0065]    The expandable proximal anchor  40  and the expandable distal anchor  42  may be formed of any suitable desired material, such as a biocompatible material including biostable, bioabsorbable, biodegradable or bioerodible materials. For instance, the expandable framework may be formed of a polymeric material or a metallic material. Some suitable polymeric materials are listed above. Some suitable metallic materials include, but are not necessarily limited to, stainless steel, tantalum, tungsten, nickel-titanium alloys such as those possessing shape memory properties commonly referred to as nitinol, nickel-chromium alloys, nickel-chromium-iron alloys, cobalt-chromium-nickel alloys, or other suitable metals, or combinations or alloys thereof. 
         [0066]    In some embodiments, the expandable framework may include one or more metals. Some examples of suitable metals and metal alloys include stainless steel, such as 304V, 304L, and 316LV stainless steel; mild steel; nickel-titanium alloy such as linear-elastic and/or super-elastic nitinol; other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625 such as INCONEL® 625, UNS: N06022 such as HASTELLOY® C-22®, UNS: N10276 such as HASTELLOY® C276®, other HASTELLOY® alloys, and the like), nickel-copper alloys (e.g., UNS: N04400 such as MONEL® 400, NICKELVAC® 400, NICORROS® 400, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035 such as MP35-N® and the like), nickel-molybdenum alloys (e.g., UNS: N10665 such as HASTELLOY® ALLOY B2®), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, and the like; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as ELGILOY®, PHYNOX®, and the like); platinum enriched stainless steel; titanium; combinations thereof; and the like; or any other suitable material. 
         [0067]    In some embodiments, the apparatus  30  may be coated with or otherwise include an elutable drug. The terms “therapeutic agents,” “drugs,” “bioactive agents,” “pharmaceuticals,” “pharmaceutically active agents”, and other related terms may be used interchangeably herein and include genetic therapeutic agents, non-genetic therapeutic agents, and cells. Therapeutic agents may be used singly or in combination. A wide range of therapeutic agent loadings can be used in conjunction with the devices of the present invention, with the pharmaceutically effective amount being readily determined by those of ordinary skill in the art and ultimately depending, for example, upon the condition to be treated, the nature of the therapeutic agent itself, the tissue into which the dosage form is introduced, and so forth. 
         [0068]    Some specific beneficial agents include anti-thrombotic agents, anti-proliferative agents, anti-inflammatory agents, anti-migratory agents, agents affecting extracellular matrix production and organization, antineoplastic agents, anti-mitotic agents, anesthetic agents, anti-coagulants, vascular cell growth promoters, vascular cell growth inhibitors, cholesterol-lowering agents, vasodilating agents, and agents that interfere with endogenous vasoactive mechanisms. 
         [0069]    More specific drugs or therapeutic agents include paclitaxel, sirolimus, everolimus, tacrolimus, Epo D, dexamethasone, estradiol, halofuginone, cilostazole, geldanamycin, ABT-578 (Abbott Laboratories), trapidil, liprostin, Actinomcin D, Resten-NG, Ap-17, abciximab, clopidogrel, Ridogrel, beta-blockers, bARKct inhibitors, phospholamban inhibitors, and Serca 2 gene/protein, resiquimod, imiquimod (as well as other imidazoquinoline immune response modifiers), human apolioproteins (e.g., AI, AII, AIII, AIV, AV, etc.), vascular endothelial growth factors (e.g., VEGF-2), as well as derivatives of the forgoing, among many others. 
         [0070]    Numerous additional therapeutic agents useful for the practice of the present invention may be selected from those described in paragraphs [0040] to [0046] of commonly assigned U.S. Patent Application Pub. No. 2003/0236514, the entire disclosure of which is hereby incorporated by reference. 
         [0071]    Those skilled in the art will recognize that aspects of the present disclosure may be manifested in a variety of forms other than the specific embodiments described and contemplated herein. Accordingly, departure in form and detail may be made without departing from the scope and spirit of the present disclosure as described in the appended claims.