Patent Publication Number: US-2022226098-A1

Title: Esophageal atresia bridge device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 16/703,136, filed Dec. 4, 2019, which claims the benefit of U.S. Provisional Application No. 62/775,689 filed Dec. 5, 2018, the entire disclosure of which is hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure pertains to medical devices, and methods for using medical devices. More particularly, the present disclosure pertains to esophageal atresia bridge devices. 
     BACKGROUND 
     Esophageal atresia is a condition where individuals are born with an incomplete esophagus which does not connect the throat to the stomach. There are several different types of esophageal atresia situations which makes it difficult for the current corrective procedures to be performed successfully. Moreover, the current procedures, for example the Fokker Process, is very invasive and causes individuals extreme trauma. In some cases, individuals are paralyzed and made unconscious for several weeks which causes weight loss and muscle wasting. The Fokker Process uses sutures which are attached to both pouch ends of the esophagus. The sutures are periodically pulled a small amount, allowing the esophagus to grow around 5 cm each time and stretch the esophagus over time. During that time, the individuals remain paralyzed and unconscious. Another shortcoming of this procedure is that the applied forces are uncontrolled and can leave the blood at the end of the esophagus unable to perfuse. As such, there is an ongoing need to provide alternative esophageal atresia bridge devices and procedures. 
     BRIEF SUMMARY 
     This disclosure provides design, material, and use alternatives for medical devices, including esophageal atresia bridge devices. 
     In a first example, an esophageal atresia bridge device may comprise a proximal anchor configured to anchor to a proximal section of an esophagus, a distal anchor configured to anchor to a distal section of the esophagus, and a brace configured to position the proximal anchor an initial distance from the distal anchor and thereafter, permit the proximal anchor to move toward the distal anchor to apply a controlled tension that pulls the proximal section of the esophagus towards the distal section of the esophagus and stretch the esophagus over time. 
     Alternatively or additionally to any of the examples above, in another example, the brace may be further configured to hold the proximal anchor and the distal anchor from moving toward and away from one another. 
     Alternatively or additionally to any of the examples above, in another example, the brace may comprise a ratchet mechanism to permit incremental advancement of the proximal anchor toward the distal anchor. 
     Alternatively or additionally to any of the examples above, in another example, the brace may comprise a screw mechanism to permit longitudinal advancement of the proximal anchor toward the distal anchor. 
     Alternatively or additionally to any of the examples above, in another example, the bridge device may comprise an expandable stent and a proximal flared region of the stent forms the proximal anchor and a distal flared region of the stent forms the distal anchor. 
     Alternatively or additionally to any of the examples above, in another example, the brace may comprise an intermediate portion of the stent between the proximal portion and the distal portion radially constrained by a sheath disposed along the intermediate portion of the stent. 
     Alternatively or additionally to any of the examples above, in another example, the sheath may include a crocheted filament configured to unravel to allow the intermediate portion to radially expand and axially contract, decreasing a distance between the proximal anchor and the distal anchor. 
     Alternatively or additionally to any of the examples above, in another example, the sheath may be configured to degrade over time to allow the intermediate portion to radially expand and axially contract, decreasing a distance between the proximal anchor and the distal anchor. 
     Alternatively or additionally to any of the examples above, in another example, the sheath may be configured to have a first portion of the sheath degrade faster than a second portion of the sheath. 
     In another example, an esophageal atresia bridge device may comprise a proximal anchor configured to anchor to a proximal section of an esophagus, a distal anchor configured to anchor to a distal section of the esophagus, and a link extending between the proximal anchor and the distal anchor. The link may be configured to position the proximal anchor at an initial first position from the distal anchor, permit the proximal anchor to move toward the distal anchor to a second position to apply a controlled tension that pulls the proximal section of the esophagus towards the distal section of the esophagus and stretch the esophagus over a first duration of time, and thereafter, further permit the proximal anchor to move further toward the distal anchor to a third position to apply a controlled tension that pulls the proximal section of the esophagus further towards the distal section of the esophagus and further stretch the esophagus over a second duration of time. 
     Alternatively or additionally to any of the examples above, in another example, the proximal anchor may comprise a flange and the distal anchor may comprise a fastener. 
     Alternatively or additionally to any of the examples above, in another example, the proximal anchor may comprise a first flange and the distal anchor may comprise a second flange. 
     Alternatively or additionally to any of the examples above, in another example, the bridge device may comprise an expandable stent and a proximal flared region of the stent forms the proximal anchor and a distal flared region of the stent forms the distal anchor and the link may comprise a radially constrained intermediate portion of the stent between the proximal portion and the distal portion, wherein radially expansion of the intermediate portion moves the proximal anchor toward the distal anchor. 
     Alternatively or additionally to any of the examples above, in another example, the link may comprise a ratchet mechanism to permit incremental advancement of the proximal anchor toward the distal anchor. 
     Alternatively or additionally to any of the examples above, in another example, the link may comprise a screw mechanism to permit longitudinal advancement of the proximal anchor toward the distal anchor. 
     In another example, an esophageal atresia bridge device may comprise an expandable stent including a proximal flared region configured to anchor to a proximal section of an esophagus, a distal flared region configured to anchor to a distal section of the esophagus, and an intermediate portion. The esophageal atresia bridge device may also comprise a sheath configured to radially constrain and axially elongate the intermediate portion. 
     Alternatively or additionally to any of the examples above, in another example, the sheath may include a set of removable sections and removing one or more of the removable sections allows the intermediate portion to radially expand and axially contract, decreasing a distance between the proximal flared region and the distal flared region. 
     Alternatively or additionally to any of the examples above, in another example, the sheath may be configured to degrade over time to allow the intermediate portion to radially expand and axially contract, decreasing a distance between the proximal flared region and the distal flared region. 
     Alternatively or additionally to any of the examples above, in another example, the sheath may include a first portion having a greater wall thickness than degrades second portion of the sheath. 
     Alternatively or additionally to any of the examples above, in another example, the sheath may be a crocheted filament configured to unravel to allow the intermediate portion to radially expand and axially contract, decreasing a distance between the proximal flared region and the distal flared region. 
     The above summary of some illustrative embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The Figures and Description which follow more particularly exemplify these and other illustrative embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure may be more completely understood in consideration of the following detailed description in connection with the accompanying drawings, in which: 
         FIGS. 1A-1C  illustrate an example of an esophageal atresia bridge device configured for emplacement in the esophagus of a patient. 
         FIGS. 2A-2C  illustrate another example of an esophageal atresia bridge device configured for emplacement in the esophagus of a patient. 
         FIG. 3A  illustrates a cut away of another example of an esophageal atresia bridge device configured for emplacement in the esophagus of a patient. 
         FIGS. 3B-3D  depict examples of a holding screw for the esophageal atresia bridge device of  FIG. 3A . 
         FIGS. 3E-3G  illustrate an example of moving the proximal anchor toward the distal anchor of the esophageal atresia bridge device of  FIG. 3A . 
         FIG. 4A  illustrates a cut away of another example of an esophageal atresia bridge device configured for emplacement in the esophagus of a patient. 
         FIGS. 4B-4C  depict examples of a driver engagement feature of the esophageal atresia bridge device of  FIG. 4A . 
         FIGS. 4D-4F  illustrate an example of moving the proximal anchor toward the distal anchor of the esophageal atresia bridge device of  FIG. 4A . 
         FIGS. 5A-5F  show access to and implantation of the esophageal atresia bridge device of  FIGS. 1A-1C . 
         FIG. 6  illustrates another example of an esophageal atresia bridge device configured for emplacement in the esophagus of a patient. 
         FIGS. 7A-7C  illustrate an example of expansion of the intermediate portion of the esophageal atresia bridge device of  FIG. 6  as a brace/link is removed. 
         FIGS. 8A-8C  illustrate another example of expansion of the intermediate portion of the esophageal atresia bridge device of  FIG. 6  as a brace/link is removed. 
         FIGS. 9A-9C  illustrate another example of expansion of the intermediate portion of the esophageal atresia bridge device of  FIG. 6  as a brace/link is removed. 
         FIGS. 10A-10D  show access to and implantation of the esophageal atresia bridge device of  FIG. 6  and the brace/link of  FIGS. 7A-7C . 
         FIGS. 11A-11C  illustrate another example of expansion of the intermediate portion of the esophageal atresia bridge device of  FIG. 6  as a brace/link is removed. 
     
    
    
     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. 
     DETAILED DESCRIPTION 
     For the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification. 
     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 terms “about” may include numbers that are rounded to the nearest significant figure. 
     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). 
     As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise. 
     It is noted that references in the specification to “an embodiment”, “some embodiments”, “other embodiments”, etc., indicate that the embodiment described may include one or more particular features, structures, and/or characteristics. However, such recitations do not necessarily mean that all embodiments include the particular features, structures, and/or characteristics. Additionally, when particular features, structures, and/or characteristics are described in connection with one embodiment, it should be understood that such features, structures, and/or characteristics may also be used connection with other embodiments whether or not explicitly described unless clearly stated to the contrary. 
     The following detailed description should be read with reference to the drawings in which similar structures in different drawings are numbered the same. The drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the disclosure. 
     The current disclosure relates to esophageal atresia bridge devices. In some cases, the bridge device may comprise a proximal anchor, a distal anchor, and a brace configured to apply a controlled tension to the esophagus that pulls a proximal section of the esophagus towards a distal section of the esophagus and stretches the esophagus over time. In some cases, the brace may be configured to hold the proximal anchor and the distal anchor from moving toward and away from one another. In some instances, the brace may be a ratchet mechanism that also permits incremental advancement of the proximal anchor towards the distal anchor. In other instances, the brace may be a screw mechanism that permits calibrated advancement of the proximal anchor towards the distal anchor. In some cases, the bridge device may be a metal stent and the brace may be a sheath configured to constrict an intermediate portion of the metal stent. In some instances, the sheath may be perforated into sections and the intermediate portion of the metal stent may radially expand and axially contract as a section of the perforated sheath is torn away to move the proximal anchor towards the distal anchor. In other instances, the sheath may be degradable and the intermediate portion of the metal stent may radially expand and axially contract as the sheath degrades over time to move the proximal anchor towards the distal anchor. 
       FIG. 1A  illustrates an example of an esophageal atresia bridge device  100  configured for emplacement in the esophagus of a patient using methods of delivery described herein. As shown, the bridge device  100  may include a brace/link  102 , a proximal anchor  104 , and a distal anchor  106 . The brace/link  102  extends from the proximal anchor  104  to the distal anchor  106 , interconnecting the proximal anchor  104  to the distal anchor  106 . In some cases, the brace  102  may be formed of any biocompatible material suitable for chronic implantation in a patient. Some examples include polymers such as soft thermoplastic materials, polyurethanes, silicone rubbers, nylon, polyethylenes, fluorinated hydrocarbon polymers, and the like. In some embodiments, the brace  102  may include a highly flexible material such as low density polyethylene (LDPE), polyvinylchloride, THV, etc. In some instances, the brace  102  may be formed from or comprise metal, for example, stainless steel, such as high tensile stainless steel, or other materials, including metals and metal alloys, such as tungsten, gold, titanium, silver, copper, platinum, palladium, iridium, ELGILOY nickel-cobalt alloys, cobalt chrome alloys, molybdenum tungsten alloys, tantalum alloys, titanium alloys, nickel-titanium alloys (e.g., nitinol), etc. The brace  102  may be formed from a lubricious polymer, such as a fluorocarbon (e.g., polytetrafluoroethylene (PTFE)), a polyamide (e.g., nylon), a polyolefin, a polyimide, or the like). Additional polymeric materials which may make up the brace  102  include polyethylene, polyvinyl chloride (PVC), ethyl vinyl acetate (EVA), polyethylene terephthalate (PET), and their mixtures and copolymers. Another useful class of polymers is thermoplastic elastomers, including those containing polyesters as components. For example, the brace  102  may be formed by extruding a rigid thermoplastic elastomer polymer. 
     The brace  102  may be colored to enhance surgical visibility by, for example, incorporating some amount of titanium dioxide. The brace may also be doped with or include a component made with a radiopaque material such as barium sulfate (BaSO 4 ), bismuth trioxide (Bi 2 O 3 ), bismuth subcarbonate (Bi 2 O 2 CO 3 ), bismuth oxychloride (BiOCl), and tungsten. Still in further embodiments, the brace  102  may be composed of a combination of several these materials either as a mixture or as a series of layers or parts that are combined, molded, welded or otherwise joined together. 
     In some cases, the brace  102  may be configured to secure the proximal anchor  104  an initial distance (D 1 ) from the distal anchor  106  and thereafter, permit the proximal anchor  104  to move toward the distal anchor  106  to apply a controlled tension that pulls a proximal section of the esophagus of the patient towards a distal section of the esophagus of the patient and stretch the esophagus over time. In some instances, as shown in  FIG. 1A , the brace  102  may include a ratchet mechanism that permits incremental advancement of the proximal anchor  104  towards the distal anchor  106 . In some examples, the ratchet mechanism may include a plurality of detents, such as a plurality of recesses  108 A- 108 E and elevations  110 A- 110 D configured to hold the proximal anchor  104  and the distal anchor  106  from moving toward and away from one another at a plurality of discrete positions. In some examples, the inclusion of a plurality of detents, such as several recesses  108 A- 108 E, offers a wider range of position options for the proximal anchor  104  relative to the distal anchor  106  that allows for a wider range of incremental tension/force magnitudes for pulling the proximal section of the esophagus to the distal section of the esophagus of the patient. It is expected that a physician may choose which detent to use based on the needs of the patient. In some cases, the recesses  108 A- 108 E may have widths larger than the proximal anchor  104 . In this configuration, the proximal anchor  104  may be allowed to move along or oscillate along the recess it is currently placed. As such, the elevations  110 A- 110 D may still be configured to hold the proximal anchor  104  at its current recess location. However, the ability to move along the recess may allow the brace  102  to apply a controlled tension or force that can vary slightly to accommodate fluctuations in the tissue of an esophagus and potentially avoid tearing of the tissue. 
     According to various embodiments, the proximal anchor  104  may comprise a collar  112  defining a lumen and a securing mechanism(s)  114  configured to push against and engage tissue of the patient when the bridge device  100  is implanted inside the proximal section of the esophagus of the patient. In some cases, the securing mechanism(s)  114  may be flanges, flaps, tines, hooks, fans, or a combination thereof, etc. that are formed as a single-piece, with the collar  112  by a molding and/or cutting process. In other instances, the securing mechanism(s)  114  may be flanges, flaps, tines, hooks, fans, or a combination thereof, etc. that are formed of multiple components. In some cases, the securing mechanism(s)  114  may have an end attached to the collar  112  in any suitable manner, which may include mechanical structures such as hinges, screws, pins and/or any other suitable fastener, or bonding such as through the use of a medical adhesive. Heat shrink tubing may be placed over the end of the securing mechanism(s)  114  for securing to the collar  112 , or laser, sonic, heat, or other welding process may be used to attach the end of the securing mechanism(s)  114  for securing to the collar  112 . 
     In some examples, the securing mechanism  114  may include several fingers, arms, or other projections that are radially spaced from one another around the collar  112 . For example, the fingers or arms of the securing mechanism  114  may be symmetrically located around the collar  112 . In some cases, the fingers or arms of the securing mechanisms  114  may be limited to one side of the collar  112 . In some instances, as shown, the securing mechanism  114  may include a continuous flange or rim of material fully surrounding the collar  112 . In some examples, the securing mechanisms may each be similar in design/structure, or, in other examples, the width, length, shape, or other features of the securing mechanisms may vary from one another. 
     In some examples, the securing mechanism(s)  114  may be attached to or configured relative to the collar  112  such that the securing mechanism(s)  114  has a desired degree of angular separation (α), with the central axis of the lumen of the collar  112 . For example, in some cases, the securing mechanism(s)  114  may be configured so that there is a 45° angle between the securing mechanism(s)  114  and the central axis of the lumen of the collar  112  in a relaxed, non-compressed state. In some cases, the angle of separation a may be 15°, 30°, 60°, 90°, etc. In some cases, the securing mechanism(s) may be configured to move, retract, or compress towards the central axis of the lumen of the collar  112  to a compressed state by applying force thereto, such as during implantation or delivery of the bridge device  100 . In some cases, the securing mechanism(s)  114  may be configured to move, swing, or extend away from the central axis of the lumen of the collar  112 , or otherwise revert from the compressed state to a non-compressed state, as shown, such as during deployment of the bridge device  100 , for example. 
     The proximal anchor  104  may be made of any biocompatible material to allow for chronic implantation in a patient. For example, any of the materials discussed above with regard to the brace  102  may be used. In some examples, the proximal anchor  104  may be made of the same material as the brace  102 . In other examples, the proximal anchor  104  may be comprised of different materials than the brace  102 . In certain embodiments, the securing mechanism(s)  114  may be comprised of a different, stiffer, material than the collar  112 . Alternatively, the securing mechanism(s)  114  may be softer than the collar  112 . According to various embodiments, multiple durometers may be used with the proximal anchor  104 . In some cases, the securing mechanism(s)  114  may be formed over a wire which may extend to or terminate short of the end of the securing mechanism(s)  114 . In some examples the securing mechanism(s)  114  may be formed of silicone while a different polymer of stiffer or harder character is used for the collar  112 . In other examples, the securing mechanism(s) may be coated or uncoated nitinol or other metal, making them generally stiffer than the lumen. In some cases, the proximal anchor  104  may be radiopaque. 
     In an example, a diameter of the lumen of the collar  112  of the proximal anchor  104  may be equal to or slightly less than an outer diameter of the recesses  110 A- 110 D of the ratchet mechanism. The lumen of the collar  112  may have a single diameter or, in other examples, the lumen of the collar  112  may have a diameter that varies along the length of the proximal anchor  104 . In some examples, the diameter of the lumen of the collar  112  may be largest at an open proximal end  116 , may taper along the length of the lumen of the collar  112 , and may be smallest at an open distal end  118 . This may be beneficial for allowing the proximal anchor  104  to more easily fit around and be placed onto the ratchet mechanism. However, this is not necessary. In some examples the collar  112  may be radially stretchable or elastic to allow the diameter of the lumen of the collar  112  to expand to allow passage over the elevations  108 A- 108 E of the ratchet mechanism through the lumen of the collar  112 . 
     According to various embodiments, the distal anchor  106  may include an elongate shaft, such as a hollow tube  120 , and a fastener  122  positioned at a distal end of the elongate shaft (e.g., the hollow tube  120 ). For clarity, the fastener  122  has been enlarged in  FIGS. 1A-1C  In some cases, during implantation of the bridge device  102 , the bridge device  102  may be connected to a delivery device (not shown) operated by an individual/physician. In some examples, the delivery device may have a handle assembly equipped with a trigger that, when pulled, actuates the fastener  122  via a lever-and-spring system, a pull wire, or other actuator, for example, within the hollow tube  120 . In the example shown in  FIG. 1A , the fastener  122  may be a clamping mechanism having distal ends configured to grip or grasp a wall of the distal section of the esophagus. In other instances, the fastener  122  may be configured to penetrate through the wall of the distal section of the esophagus to engage the fastener  122  with the wall of the distal section of the esophagus. In other examples, the fastener  122  may be a hook, pin, screw latch, clip, or any mechanism configured engage the wall of the distal section of the esophagus to anchor the bridge device  102  to the distal section of the esophagus. In some cases, the fastener  122  may be initially open and close when actuated, such as when the trigger is pulled. Moreover, the handle assembly may also have a locking mechanism configured to lock the fastener  122  closed to keep the bridge device  102  anchored to the distal section of the esophagus. Variations on the basic form of the distal anchor  106  (e.g., the hollow tube  120  and the fastener  122 ) may be implemented depending on the needs/preferences of the patient and physician and variations can be made in the length and weight of the distal anchor  106 . Additionally, the distal anchor  106  may be made of any biocompatible material to allow for chronic implantation in a patient, such as any of the materials discussed above with regard to the brace  102  or the proximal anchor  104  and in various embodiments, the hollow tube  102  and the fastener  122  may be comprised of the same or different materials. 
       FIGS. 1A-1C  illustrate an example of selectively reducing the distance between the proximal anchor  104  and the distal anchor  106 , such as moving the proximal anchor  104  along the brace  102  toward the fastener  122 . According to various embodiments, the proximal anchor  104  may be placed on the brace  102  (i.e., the ratchet mechanism) by moving elevation  108 A through the lumen of the collar  112  of the proximal anchor  104  and advancing the proximal anchor  104  onto the recess  110 A to an initial distance (D 1 ) from the distal anchor  106 , as shown in  FIG. 1A . As discussed above, the collar  112  may be formed of a suitable flexible material so that it may be radially stretched over the elevation  108 A and the recess  110 A to move the proximal anchor  104  axially along the brace  102 . Accordingly, the proximal anchor  104  may fit snuggly around the recess  110 A and be coupled to the ratchet mechanism. As such, the elevations  108 A and  108 B of the ratchet mechanism may be configured to hold the proximal anchor  104  at a first discrete location, thus inhibiting the proximal anchor  104  from moving any further toward or away from the distal anchor  106 . Turning to  FIG. 8B , in some cases, a physician may move the elevation  108 B through the lumen of the collar  112  and advance the proximal anchor  104  onto the recess  110 B a distance (D 2 ) from the distal anchor  106 , and thus closer to the distal anchor  106  than the first discrete location. As such, the elevations  108 B and  108 C of the ratchet mechanism may be configured to hold the proximal anchor  104  at a second discrete location, thus inhibiting the proximal anchor  104  from moving any further toward or away from the distal anchor  106 . Similarly, turning to  FIG. 8C , a physician may then move the elevation  108 C through the lumen of the collar  112  and advance the proximal anchor  104  onto the recess  110 C a distance (D 3 ) from the distal anchor  106 , and thus closer to the distal anchor  106  than the second discrete position. The elevations  108 C and  108 D may then hold the proximal anchor  104  at a third discrete location, thus inhibiting the proximal anchor  104  from moving any further toward or away from the distal anchor  106 . In some cases, the recesses  110 A- 110 D may have widths larger than the length of the lumen of the collar  112 . In this configuration, the proximal anchor  104  may be allowed to move along or oscillate along the recess which it is currently placed a limited amount. As such, the elevations  108 A- 108 E may still be configured to hold the proximal anchor  104  at its current recess location. However, the ability to move along the recess a limited amount may allow the brace  102  to apply a controlled tension or force that can vary slightly to accommodate fluctuations in the tissue of an esophagus and potentially avoid tearing of the tissue. The distance between the proximal anchor  104  and the distal anchor  106  may be periodically reduced over the courses of hours, days, or weeks until the proximal anchor  106  has been moved toward the distal anchor  106  a sufficient amount to connect two disconnected portions of the esophagus. 
       FIGS. 2A-2C  illustrate another example of selectively reducing the distance between the proximal anchor  104  and a distal anchor  206 , such as moving the proximal anchor  104  along the brace  102  toward the distal anchor  206 . In this example, the distal anchor  206  may be configured similar to the proximal anchor  104  and be comprised of similar materials. According to various embodiments, the proximal anchor  104  may be placed on the brace  102  (i.e., the ratchet mechanism) by moving elevation  108 A through the lumen of the collar  112  of the proximal anchor  104  and advancing the proximal anchor  104  onto the recess  110 A to an initial distance (D 1 ) from the distal anchor  206 , as shown in  FIG. 2A . As such, the elevations  108 A and  108 B of the ratchet mechanism may be configured to hold the proximal anchor  104  at a first discrete location, thus inhibiting the proximal anchor  104  from moving any further toward or away from the distal anchor  206 . Turning to  FIG. 8B , the elevation  108 B may be moved through the lumen of the collar  112  and the proximal anchor  104  may be advanced onto the recess  110 B a distance (D 2 ) from the distal anchor  106 , and thus closer to the distal anchor  206  than the first discrete location. The elevations  108 B and  108 C may then hold the proximal anchor  104  at a second discrete location, thus inhibiting the proximal anchor  104  from moving any further toward or away from the distal anchor  206 . Similarly, turning to  FIG. 8C , the elevation  108 C may be moved through the lumen of the collar  112  and the proximal anchor  104  may be advanced onto the recess  110 C a distance (D 3 ) from the distal anchor  206 , and thus closer to the distal anchor  206  than the second discrete position. The elevations  108 C and  108 D may then hold the proximal anchor  104  at a third discrete location, thus inhibiting the proximal anchor  104  from moving any further toward or away from the distal anchor  206 . In some cases, the distal anchor  206  may be advanced along the brace  102  similar to that described for the proximal anchor  104 , but in an opposite direction, to move the distal anchor  206  closer to the proximal anchor  104 . Moreover, in some examples, the recesses  110 A- 110 D may have widths larger than the length of the lumens of the collars of the proximal and distal anchors. In this configuration, the proximal and/or distal anchor may be allowed to move along or oscillate along the recess which it is currently placed a limited amount. As such, the elevations  108 A- 108 E may still be configured to hold the proximal and/or distal anchors at their current recess location. However, the ability to move along the recess a limited amount may allow the brace  102  to apply a controlled tension or force that can vary slightly to accommodate fluctuations in the tissue of an esophagus and potentially avoid tearing of the tissue. In other instances, the distal anchor  206  may be immovably fixed to the brace  102 , such that only the proximal anchor  104  is permitted to be moved longitudinally along the brace  102  to one of a plurality of discrete locations. The distance between the proximal anchor  104  and the distal anchor  206  may be periodically reduced over the courses of hours, days, or weeks until the proximal anchor  106  has been moved toward the distal anchor  206  a sufficient amount to connect two disconnected portions of the esophagus. 
       FIG. 3A  illustrates a cut away of another example of an esophageal atresia bridge device  300  configured for emplacement in the esophagus of a patient using methods of delivery described herein. As shown, the bridge device  300  may include a brace/link  302 A and  302 B, a proximal anchor  304 , and a distal anchor  306 . In some cases, the proximal anchor  304  and the proximal brace portion  302 A may be combined, fastened, molded, welded or otherwise joined together. For example, the proximal brace portion  302 A may be fixedly secured to the proximal anchor  304 , rotationally coupled to the proximal anchor  304 , movably attached to the proximal anchor  304 , or formed with the proximal anchor  304 . In some cases, the distal anchor  306  and the distal brace portion  302 B may be combined, fastened, molded, welded or otherwise joined together. For example, the distal brace portion  302 B may be fixedly secured to the distal anchor  306 , rotationally coupled to the distal anchor  306 , movably attached to the distal anchor  306 , or formed with the distal anchor  306 . 
     Similar to the bridge device  100 , the bridge device  300  may be formed of any biocompatible material suitable for chronic implantation in a patient. In some instances, as shown in  FIG. 3A , the brace, including brace portions  302 A/ 302 B, may be a screw mechanism that permits infinitely controlled advancement of the proximal anchor  304  towards the distal anchor  306 . For instance, the proximal brace portion  302 A may include a threaded region threadably engaged with a mating threaded region of the distal brace portion  302 B. For instance, the threaded region of the proximal brace portion  302 A may be a externally threaded post threadably engaging an internally threaded bore of the distal brace portion  302 B, or vice versa. 
     In some cases, to lessen the probability that the proximal anchor  304  will rotate upon rotational advancement of the proximal brace portion  302 A along threaded portion of the distal brace portion  302 B, the proximal anchor  304  may have an inner diameter that is configured to fit around a bushing  308  or another separating element. Moreover, a holding screw  310  (or another fastening element) may be placed through an inner diameter of the bushing  308  such that a rim  312  of the holding screw  310  may be adjacent to the proximal anchor  304  or on the opposite side of the brace portion  302 A and couple the proximal anchor  304  to the brace portion  302 A. Accordingly, as the brace portion  302 A rotates during advancement along the threaded portion of the distal brace portion  302 B, the proximal anchor  304  may sit on the bushing  308  and avoid being rotated with the brace portion  302 A. This may prevent the proximal anchor  304  from rubbing/scrapping against the tissue of an esophagus during advancement of the proximal anchor  304  toward the distal anchor  306  and potentially avoid tearing of the tissue. 
     In some cases, the screw mechanism may include the brace portion  302 A as a post having external threading  317  and the brace portion  302 B as a shell having an inner cavity  314  having internal threading  318  configured to mate with the threading of the brace portion  302 A. The brace portion  302 A may extend through the inner cavity  314  of the brace portion  302 B and the distal anchor  306 . Moreover, brace portion  302 B may allow the brace portion  302 A to rotate through the cavity  314 . 
     Turning to  FIGS. 3B-3D , several examples are shown depicting a driver interface of the proximal brace portion  302 A, such as formed in a proximal face of the holding screw  310 .  FIG. 3B  illustrates the driver interface of the brace portion  302 A having a hexagon indention configured to receive a hex key to allow a physician to rotate the proximal brace portion  302 A using the hex key.  FIG. 3C  illustrates the driver interface of the brace portion  302 A having an “X” indention configured to receive a Phillips head screw driver to allow a physician to rotate the proximal brace portion  302 A using the Phillips head screw driver.  FIG. 3D  illustrates the driver interface of the brace portion  302 A having a slit indention configured to receive a flat head screw driver to allow a physician to rotate the proximal brace portion  302 A using the flat head screw driver. Although only three embodiments of the driver interface are shown, the driver interface may be configured in any suitable manner that permits a driver to interface with the brace portion  302 A to rotate the proximal brace portion  302 A relative to the distal brace portion  302 B to advance the proximal anchor  304  toward the distal anchor  306 . 
       FIGS. 3E-3G  illustrate an example of moving the proximal anchor  304  toward the distal anchor  306 . According to various embodiments, the threaded portion  317  of the proximal brace portion  302 A may be threadably engaged with the threaded portion  318  of the distal brace portion  302 B, as shown in  FIG. 3E , such that the proximal anchor  304  is an initial distance (D 1 ) from the distal anchor  306 . Turning to  FIG. 3F , in some cases, a physician may use a tool to rotate the proximal brace portion  302 A relative to the distal brace portion  302 B to advance the proximal anchor  304  toward the distal anchor  306  to a desired distance (D 2 ) from the distal anchor  306 . As such, the threads of the proximal brace portion  302 A and the threads of the distal brace portion  302 B may be configured to hold the proximal anchor  304  from moving any further toward or away from the distal anchor  306  once the desired distance is reached. Similarly, turning to  FIG. 3G , a physician may use a tool to further rotate the proximal brace portion  302 A relative to the distal brace portion  302 B to further advance the proximal anchor  304  toward the distal anchor  306  to a desired distance (D 3 ) from the distal anchor  306 . The threads of the proximal brace portion  302 A and the threads of the distal brace portion  302 B may then hold the proximal anchor  304  from moving any further toward or away from the distal anchor  306  once the desired distance is reached. Further adjustment of the distance between the proximal anchor  304  and the distal anchor  306  may be periodically performed over the course of hours, days, or weeks until the proximal anchor  304  has been moved toward the distal anchor  306  a sufficient amount to connect two disconnected portions of the esophagus. 
       FIG. 4A  illustrates a cut away of another example of an esophageal atresia bridge device  400  configured for emplacement in the esophagus of a patient using methods of delivery described herein. As shown, the bridge device  400  may include a brace/link  402 , a proximal anchor  404 , and a distal anchor  406 . In some cases, the distal anchor  406  and the brace  402  may be combined, fastened, molded, welded or otherwise joined together. For example, the brace  402  may be fixedly secured to the distal anchor  406 , rotationally coupled to the distal anchor  406 , movably attached to the distal anchor  406 , or formed with the distal anchor  406 . 
     Similar to the bridge device  100 , the bridge device  400  may be formed of any biocompatible material suitable for chronic implantation in a patient. In some instances, as shown in  FIG. 4A , the brace  402  may be a screw mechanism that permits infinitely controlled advancement of the proximal anchor  404  towards the distal anchor  406 . For instance, the proximal anchor  404  may include a threaded region threadably engaged with a mating threaded region of the brace  402 . For instance, proximal anchor  404  may include an internally threaded collar mating with an externally threaded region of the brace  402 , such as a threaded post, or vice versa. 
     According to various embodiments, the proximal anchor  404  may comprise a collar  408  defining a lumen and a securing mechanism(s)  410 . In some cases, to lessen the probability that the securing mechanism(s)  410  will rotate upon advancement of the proximal anchor  404 , the securing mechanism(s)  410  may have an inner diameter that is configured to fit around a bushing  412  or another separating element and a recess  414  of the collar  408 . Moreover, the collar  408  may also have a ridge  416  that is adjacent to the securing mechanism(s)  410  and holds the securing mechanism(s)  410  in place when the securing mechanism(s)  410  is in the recess  414 . Accordingly, as the collar  408  rotates during advancement of the proximal anchor  404  toward the distal anchor  406 , the securing mechanism(s)  410  may not be rotated. This may prevent the securing mechanism(s)  410  from rubbing/scrapping against the tissue of an esophagus during advancement and potentially avoid tearing of the tissue. In some cases, the brace  402  may be a screw having external threading  417  and the collar  408  may be a shell having internal threading  418  that extends through the lumen of the collar  408 . Moreover, an inner wall  420  of the collar  408  may be comprised of threads  418  (e.g., “female threads”) to allow the collar  408  to rotate over the screw brace  402 . 
     Turning to  FIGS. 4B and 4C , examples are shown depicting a driver interface of the collar  408 .  FIG. 4B  illustrates the driver interface of the collar  408  having a hexagon shape to receive a tool, such as a wrench or socket, to allow a physician to rotate the collar  408  using the tool.  FIG. 4C  illustrates the driver interface of the collar  408  having a circular shape with jagged edges configured to receive a similar circular jagged edge shaped tool, such as a wrench or socket, to allow a physician to rotate the collar  408  using the circular jagged edge shaped tool. Although only two shapes of the driver interface are shown, the driver interface of the collar  408  may be configured in any suitable manner that allows a physician to rotate the collar  408  relative to the brace  402  to advance the proximal anchor  404  toward the distal anchor  406 . 
       FIGS. 4D-4F  illustrate an example of moving the proximal anchor  404  toward the distal anchor  406 . According to various embodiments, an end of the screw brace  402  may be placed in the threaded bore of the collar  408  of the proximal anchor  404  and aligned with the threads such that the proximal anchor  404  is an initial distance (D 1 ) from the distal anchor  406 , as shown in  FIG. 4D . Turning to  FIG. 4E , in some cases, a physician may use a tool to rotate the collar  408  relative to the brace  402  to advance the proximal anchor  404  toward the distal anchor  406  to a desired distance (D 2 ) from the distal anchor  406 . As such, the threads of the screw brace  402  and the threads of the collar  408  may be configured to hold the proximal anchor  404  from moving any further toward or away from the distal anchor  406  once the desired distance is reached. Similarly, turning to  FIG. 4F , a physician may use a tool to further rotate the collar  408  relative to the brace  402  to further advance the proximal anchor  404  toward the distal anchor  406  to a desired distance (D 3 ) from the distal anchor  406 . The threads of the screw brace  402  and the threads of the collar  408  may then hold the proximal anchor  404  from moving any further toward or away from the distal anchor  406  once the desired distance is reached. Further adjustment of the distance between the proximal anchor  404  and the distal anchor  406  may be periodically performed over the course of hours, days, or weeks until the proximal anchor  404  has been moved toward the distal anchor  406  a sufficient amount to connect two disconnected portions of the esophagus. 
       FIGS. 5A-5F  show access to and implantation of the esophageal atresia bridge device  100  from  FIGS. 1A-1C . Starting with  FIGS. 5A and 5B , the bridge device  100  may be connected to a delivery device  500  that may include a detachable handle assembly  502  and a hollow tube  504 . In some cases, the handle assembly  502  may include a trigger  506  that, when pulled, actuates the fastener  122  of the distal anchor  106 . In some instances, when the trigger  506  is pulled, the fastener  122  may close and when the trigger  506  is turned, the fastener  122  may be locked into the closed position. Access to an esophagus (see  FIGS. 5C-5F ) may be obtained through the mouth of the patient or using standard access techniques known in the art. In another technique, the stomach may be punctured with a hollow needle or trocar, for example under ultrasound guidance, to gain access to the patient&#39;s stomach. Moreover, other implanting techniques may be used instead. 
     Turning to  FIG. 5C , into the access (e.g., the mouth), an introducer sheath may be inserted and advanced to a location near an end  512  of a proximal section  510  of the esophagus  508 . Contrast injection may be useful to visualize the proximal section  510  of the esophagus  508 . The delivery device  500  with the bridge device  100  may then be introduced through the introducer sheath. In an example, the delivery device  500  with the bridge device  100  may be advanced to a desired location relative to the end  512  of the proximal section  510 . The fastener  122  of the bridge device  100 , which may be deflectable or steerable, can then extend from the proximal section  510  to an end  516  of a distal section  514  of the esophagus  508 , spaced apart and detached from the proximal section  510 . In some cases, the fastener  122  may be configured to penetrate through the end  512  of the proximal section  510  and advanced to the end  516  of the distal section  514  of the esophagus  508 . In some examples, the trigger  506  of the delivery device  500  may then be actuated to close the fastener  122  and turned to lock the fastener  122  in the closed position. As such the distal anchor  106  may now be anchored to the distal section  514  of the esophagus. Furthermore, the proximal anchor  104  may be expanded or deployed in the proximal section  510  of the esophagus  508  into engagement with tissue of a luminal wall of the proximal section  510  of the esophagus  508 . 
     According to various embodiments, the proximal anchor  104  may then be advanced along the brace  102  to an initial distance (D 1 ) from the distal anchor  106 . In some cases, the securing mechanism(s)  114  of the proximal anchor  104  may be configured to push against and engage the tissue of the luminal surface of the proximal section  510  of the esophagus  508  near the end  512  of the proximal section  510  and anchor the proximal anchor  104  to the proximal section  510  of the esophagus  508 . In some instances, in this position, the bridge device  100  may apply a controlled tension that pulls the proximal section  510  of the esophagus  508  towards the distal section  514  of the esophagus  508  and stretch the esophagus over time. Turning to  FIG. 5D , after the esophagus has had time to stretch, the proximal anchor  104  may be advanced toward the distal anchor  106  to a distance (D 2 ) from the distal anchor  106 . Accordingly, the bridge device  100  may again apply a controlled tension that pulls and stretches the proximal section  510  of the esophagus  508  further towards the distal section  514  of the esophagus  508 . Similarly, turning to  FIG. 8D , after the esophagus has had time to stretch, the proximal anchor  104  may be further advanced toward the distal anchor  106  to a distance (D 3 ) from the distal anchor  106 . As such, the bridge device  100  may again apply a controlled tension that further pulls and stretches the proximal section  510  of the esophagus  508  further towards the distal section  514  of the esophagus  508 . In some cases, the proximal anchor  104  may be allowed to move slightly or oscillate along the recess it is currently placed. As such, the bridge device  100  may apply a controlled tension or force that can vary slightly to accommodate fluctuations in the tissue of the esophagus  508  and potentially avoid tearing of the tissue. 
     Turning to  FIG. 5F , when the proximal section  510  is close enough to the distal section  514  of the esophagus  508  the bridge device  100  may be removed and the disconnected portions of the esophagus may be connected. Accordingly, the proximal section  510  may be connected to the distal section  514 , such as with sutures (i.e., the proximal section  510  and/or the distal section  514  have been stretched enough such that any tension administered to connect the proximal section to the distal section will not cause unwanted tearing of the tissue of the proximal section or the distal section). 
     It is noted that the medical procedure described above can be performed with any of the devices described herein. For instance, the distal anchor  206 ,  306  or  406  may be advanced into the distal section  514  of the esophagus and expanded to anchor the device to the distal section  514  of the esophagus, while the proximal anchor  104 ,  304  or  404  is expanded or deployed in the proximal section  510  of the esophagus. Thereafter, the proximal anchor may be controllably moved toward the distal anchor until the proximal section  510  of the esophagus is sufficiently drawn to the distal section  514  of the esophagus to connect the proximal and distal sections  510 / 514  of the esophagus together. 
       FIG. 6  illustrates another example of an esophageal atresia bridge device  600  configured for emplacement in the esophagus of a patient using methods of delivery described herein. In some cases, the bridge device  600  may be a radially expandable stent formed from a plurality of braided wires  602 . In certain embodiments, the braided wires  602  may have a first set of wire segments that extend parallel to one another in a first helical direction and a second set of wire segments that extend parallel to one another in a second helical direction, opposite of the first helical direction. As such, the first set of wire segments and the second set of wire segments may cross or intersect multiple times at the crossover points to form a braid pattern. In some cases, the braid pattern may be uneven or non-uniform because the spacing between the individual wire segments from either set of wire segments may vary or the angle at which the wire segments cross may vary. In some instances the braid pattern may be in a one-under and one-over braiding configuration in which a single wire segment extending in the first helical direction intersects a single wire segment extending in the second helical direction at each crossover point. In the one-under and one-over braiding configuration, a wire segment from the first set of wire segment may be located above (radially outward of) a first wire segment from the second set of wire segments at a first crossing (i.e., crossover point), then below a second wire segment from the second set of wire segments at a second crossing (i.e., crossover point), then above a third wire segment from the second set of wire segments at a third crossing (i.e., crossover point), and continue in this alternating pattern from a proximal end  604  of the bridge device  600  to a distal end  606  of the bridge device  600 . Moreover, the other wires from the braided wires  602  may also be braided in this alternating pattern from the proximal end  604  to the distal end  606 . In various embodiments, the one-under and one-over configuration of the wires may define a plurality open cells (e.g., open cell  608 ). Open cells may be openings through the tubular wall of the bridge device  600 . The open cells may have a parallelogram shape, having upper apexes, lower apexes, and side apexes formed by the crossover points (e.g., crossover points  610 - 616 ). The braided wires  602  are not limited to the one-under and one-over configuration. In some alternate configurations, the braided wires  602  may be braided in a two-under and a two-over pattern. Other braiding patterns known in the art may also be suitably used. Further, in some cases, the braided wires  602  may be paired with one another and braided by using each pair of wires in a one-under and one-over pattern. The pairs of wires may be the same or may be different (e.g., may have the same or different dimensions, shapes and/or materials of construction). Moreover, the pairs of wires may suitably be braided in other braided patterns, such as but not limited to, for example, the two-under and two-over pattern. 
     According to various embodiments, the braided wires  602  may be made from any suitable implantable material, including without limitation nickel-titanium alloy (e.g., nitinol), stainless steel, cobalt-based alloy such as Elgiloy®, platinum, gold, titanium, tantalum, niobium, polymeric materials and combinations thereof. Useful polymeric materials may include, for example, polyesters, including polyethylene terephthalate (PET) polyesters, polypropylenes, polyethylenes, polyurethanes, polyolefins, polyvinyls, polymethylacetates, polyamides, naphthalane dicarboxylene derivatives, natural silk, polyvinyl chloride, polytetrafluoroethylene, including expanded polytetrafluoroethylene (ePTFE), fluorinated ethylene propylene copolymer, polyvinyl acetate, polystyrene, poly(ethylene terephthalate), naphthalene dicarboxylate derivatives, such as polyethylene naphthalate, polybutylene naphthalate, polytrimethylene naphthalate and trimethylenediol naphthalate, polyurethane, polyurea, silicone rubbers, polyamides, polycarbonates, polyaldehydes, natural rubbers, polyester copolymers, styrene-butadiene copolymers, polyethers, such as fully or partially halogenated polyethers, and copolymers and combinations thereof. Further, useful and nonlimiting examples of polymeric stent materials include poly(L-lactide) (PLLA), poly(D,L-lactide) (PLA), poly(glycolide) (PGA), poly(L-lactide-co-D,L-lactide) (PLLA/PLA), poly(L-lactide-co-glycolide) (PLLA/PGA), poly(D,L-lactide-co-glycolide) (PLA/PGA), poly(glycolide-co-trimethylene carbonate) (PGA/PTMC), polydioxanone (PDS), Polycaprolactone (PCL), polyhydroxybutyrate (PHBT), poly(phosphazene) poly(D,L-lactide-co-caprolactone) PLA/PCL), poly(glycolide-co-caprolactone) (PGA/PCL), poly(phosphate ester) and the like. Wires made from polymeric materials may also include radiopaque materials, such as metallic-based powders, particulates or pastes which may be incorporated into the polymeric material. For example, the radiopaque material may be blended with the polymer composition from which the polymeric wire is formed, and subsequently fashioned into the stent as described herein. Alternatively, the radiopaque material may be applied to the surface of the metal or polymer stent. In either embodiment, various radiopaque materials and their derivatives may be used including, without limitation, bismuth, barium and its derivatives such as barium sulphate, tantulaum, tungsten, gold, platinum and titanium, to name a few. Additional useful radiopaque materials may be found in U.S. Pat. No. 6,626,936, which is herein incorporated in its entirety by reference. Metallic complexes useful as radiopaque materials are also contemplated. The bride device  600  may be selectively made radiopaque at desired areas along the wire or may be fully radiopaque, depending on the desired end-product and application. Further, the braided wires  602  may have an inner core of tantalum, gold, platinum, iridium or combinations thereof and an outer member or layer of nitinol to provide a composite wire for improved radiopacity or visibility. In some cases, the inner core may be platinum and the outer layer may be nitinol. In some cases, the inner core of platinum may represent about at least 10% of the wire based on the overall cross-sectional percentage. Moreover, nitinol that has not been treated for shape memory such as by heating, shaping and cooling the nitinol at its martensitic and austenitic phases, may also useful as the outer layer. Further details of such composite wires may be found in U.S. Pat. No. 7,101,392, the contents of which is incorporated herein by reference. 
     In some cases, the bridge device  600  may include a proximal portion  618 , an intermediate portion  626 , and a distal portion  620 . In some examples, the proximal portion  618  may include a proximal anchor  622  and the distal portion  620  may include a distal anchor  624 . In some cases, the proximal anchor  622  and the distal anchor  624  may be a flare, flange, or an elevation of the braided wires  602 . That is, the proximal anchor  622  may be flared end region of the stent having a larger radius compared to the intermediate portion  626 , and the distal anchor  624  may be a flared end region of the stent having a larger radius compared to the intermediate portion  626 . In some cases, the proximal anchor  622  and the distal anchor  624  may be configured to radially expand to push against and engage tissue of the patient when the bridge device  600  is implanted inside the proximal section and the distal section of the esophagus of the patient. In some cases, the anchors  622  and  624  may include hooks, pins, tines, and/or any other suitable element that can assist in anchoring the bridge device  600  to the esophagus of the patient. In some examples, the anchors  622  and  624  may be shaped such that the anchors  622  and  624  may potentially have an optimal anchoring configuration. For instance, in some cases, the anchors  622  and  624  may be geometrically shaped and have an angle of incline from the proximal and distal portions  618  and  620  that allow the anchors  622  and  624  to have an optimal amount of surface area to engage the tissue of the esophagus. For example, in some cases, the anchors  622  and  624  may have a 90° incline, approximately, from the proximal and distal portions  618  and  620  and relatively flat edges to engage the tissue of the esophagus. In some cases, the anchors  622  and  624  may have an angle of incline of approximately 100°, 115°, 130°, 160°, etc. and have rounded edges, pointed edges, etc. In some cases, the anchors  622  and  624  may be configured to move, retract, or compress towards the bridge device  600  to prevent tearing of the tissue when implanted in the esophagus. 
       FIGS. 7A-7C  illustrate an example of expansion of the intermediate portion  626  as a brace/link (e.g., a sheath  700 ) is removed from the bridge device  600 . The sheath  700  may be comprised of materials known in the art for sheaths. In some cases, the sheath  700  may have a generally consistent surface and cross-section. In some embodiments, the sheath  700  may include one or more, or a plurality of frangible regions, configured to separate from the remainder of the sheath  700 . For instance, the sheath  700  may have areas that are weaker than other portions to provide preferential tear lines  702 A- 702 E (e.g., score lines, perforations, and/or thinner portions), so that the sheath  700  may tear at the preferential tear lines  702 A- 702 E. In some instances, the preferential tear lines  702 A- 702 E may be molded, cut, etched, or otherwise formed in the sheath  700 . In other instances, the preferential tear lines  702 A- 702 E can be created by softening the desired area of the sheath  700  with heat, or otherwise deforming the structure of the sheath material at the desired location. In some cases, the preferential tear lines  702 A- 702 E may be selectively positioned about the sheath  700  so that portions of the sheath  700  are removed or detached in a selected and controlled manner. For instance, the preferential tear lines  702 A- 702 E may be positioned such that the sheath  700  includes removable sections  704 A- 704 F, which may be separable from one another. Optionally, the removable sections  704 A- 704 F may be initially joined and the sheath  700  may include string(s)  706 A- 706 F, cords, ropes, strands, or any other element configured to separate a removable section from the remainder of the sheath  700  at the preferential tear line  702 A- 702 E. 
     As shown in  FIG. 7A , in some cases, the sheath  700  may be placed onto the intermediate portion  626  of the bridge device  600  using methods known in the art. In some cases, the intermediate portion  626  may be restrained in a radially compressed configuration by the sheath  700 . According to various embodiments, the sheath  700  may radially compress the intermediate portion  626  to axially elongate the intermediate portion  626  such that the proximal portion  618  is an initial distance (D 1 ) from the distal portion  620 . Turning to  FIG. 7B , in some instances, a physician may pull on the strings (e.g., strings  706 A- 706 B and  706 E- 706 F) or otherwise manipulate the sheath  700  of the bridge device  600  to detach the removable sections (e.g., removable section  704 A- 704 B and  704 E- 704 F) at the preferential tear lines (e.g., preferential tear lines  702 A- 702 B and  702 D- 702 E) and tear the removable sections from the sheath  700 . In some examples, the removal (e.g., tearing away) of the removable sections may allow the intermediate portion  626  to radially expand to axially contract the intermediate portion  626  to decrease the distance between the proximal portion  618  and the distal portion  620  to distance D 2 , less than distance D 1 . Additionally, turning to  FIG. 7C , a physician may pull on the strings (e.g., strings  706 C- 706 D) or otherwise manipulate the sheath  700  of the bridge device  600  to detach the removable sections (e.g., removable section  704 C- 704 D) at the preferential tear line (e.g., preferential tear line  702 C) and tear the removable sections from the sheath  700 . In some examples, the removal (e.g., tearing away) of the removable sections may allow an additional portion of the intermediate portion  626  to radially expand to further axially contract the intermediate portion  626  to further decrease the distance between the proximal portion  618  and the distal portion  620  to distance D 3 , less than distance D 2 . Thus, with the proximal anchor  622  expanded in the disconnected proximal portion and the distal anchor  624  expanded in the disconnected distal portion of an esophagus, the distance between the proximal anchor  622  and the distal anchor  624  may be periodically reduced over the course of hours, days, or weeks by removing portions of the sheath  700  until the proximal anchor  622  has been moved toward the distal anchor  624  a sufficient amount to connect the two disconnected portions of the esophagus together. 
       FIGS. 8A-8C  illustrate another example of radial expansion and axial contraction of the intermediate portion  626  as a brace/link (e.g., sheath  800 ) is removed from the bridge device  600 . The bridge device  600  includes a sheath  800  surrounding the intermediate portion  626  to radially constrain, and thus axially elongate the intermediate portion of the braided stent while the flanges of the braided stent, forming the proximal and distal anchors  622 / 624  are radially expanded. In some cases, the sheath  800  may be comprised of materials that allow the sheath  800  or portions thereof to degrade over time. In some instances, the sheath  800  may have areas of varying material, wall thickness, or strength across its length, so that certain portions of the sheath  800  may degrade faster than other portions, providing the sheath  800  with a progressively shorter length over a period of degradation. In the embodiment depicted in  FIG. 8A , the sheath  800  has a varying rate of degradation along its length, which in the particular embodiment is achieved by varying a wall thickness along its length. In this case, an intermediate section  802  may have a greater wall thickness than at a proximal end  804  and distal end  806  of the sheath  800 , respectively. Moreover, in some examples, the wall thickness of the sheath  800  may get progressively thinner moving away from the intermediate section  802  towards the proximal end  804  and distal end  806 . In some cases, the thinner proximal end  804  and distal end  806  may fully degrade over time sooner than the intermediate section  802 . As such, the thickened and stronger intermediate section  802  of the sheath  800  may resist radial expansion of the underlying intermediate portion of the stent longer than the portions of the intermediate portion of the stent underlying the proximal end  804  and distal end  806  of the sheath  800 . As the portions of the intermediate portion of the stent are no longer radially constrained by the sheath  800 , those portions of the intermediate portion of the stent are permitted to radially expand and thus axially contract to reduce the axial distance between the proximal anchor  622  and the distal anchor  624 . This is just one example of how the sheath  800  may be configured to allow for a variation in the degradation rate of regions of the sheath  800 . 
     In some examples, the wall thickness along the length of the sheath  800  may be relatively constant and the intermediate section  802  may be comprised of material that degrades slower than material comprising the proximal end  804  and distal end  806  of the sheath  800 , providing the sheath  800  with a gradient of degradation along its length. Similarly, the proximal end  804  and distal end  806  may fully degrade over time sooner than the intermediate section  802 , permitting controlled radially expansion of the underlying intermediate portion of the stent from the ends of the intermediate portion toward the central region of the intermediate portion. In some cases, a combination of material composition and varying wall thickness may be used to obtain controlled degradation of the sheath  800 . 
     As shown in  FIG. 8A , in some cases, the sheath  800  may be placed onto the intermediate portion  626  of the bridge device  600  (e.g., surround the intermediate portion of the braided stent, with the flared ends of the stent located on either end of the sheath  800  using methods known in the art. In some cases, the intermediate portion  626  may be restrained in a radially compressed configuration by the sheath  800 . According to various embodiments, the sheath  800  may radially compress, and axially elongate the intermediate portion  626  such that the proximal portion  618  is an initial distance (D 1 ) from the distal portion  620 . Turning to  FIG. 8B , in some instances, the sheath  800 , formed of a biodegradable material, may degrade over time. In this case, because the wall thickness is greater at the intermediate section  802  than the proximal end  804  and distal end  806 , the proximal end  804  and distal end  806  may fully degrade before the intermediate section  802 . In some examples, the degrading of the sheath  800  may allow the exposed portions of the intermediate portion  626  of the bridge device  600  to radially expand and axially contract to decrease the distance between the proximal portion  618  and the distal portion  620  to distance D 2 , less than distance D 1 . At this point, portions of the intermediate portion  626  still underlying the sheath  800  may remain held in a radially contracted state. Additionally, turning to  FIG. 8C , the sheath  800  may continue to degrade over time from its ends toward the central region of the sheath  800 . In this case, the sheath  800  may fully degrade over time allowing the intermediate portion  626  to further radially expand and axially contract to decrease the distance between the proximal portion  618  and the distal portion  620  to distance D 3 , less than distance D 2 . 
       FIGS. 9A-9C  illustrate another example of radial expansion and axial contraction of the intermediate portion  626  as a brace/link (e.g., sheath  900 ) is removed from the bridge device  600 . The bridge device  600  includes a sheath  900  surrounding the intermediate portion  626  to radially constrain, and thus axially elongate the intermediate portion of the braided stent while the flanges of the braided stent, forming the proximal and distal anchors  622 / 624  are radially expanded. Similar to sheath  800 , the sheath  900  may be comprised of materials that allow the sheath  900  or portions thereof to degrade over time. In some instances, the sheath  900  may have areas of varying material, wall thickness, or strength across its length, so that certain portions of the sheath  900  will degrade faster than other portions, providing the sheath  900  with a progressively shorter length over a period of degradation. In the embodiment depicted in  FIG. 9A , the sheath  900  has a varying rate of degradation along its length, which in the particular embodiment is achieved by varying a wall thickness along its length. In this case, a first end, such as distal end  906 , may have a greater wall thickness than a second end, such as proximal end  904 , of the sheath  900 , respectively. Moreover, in some examples, the wall thickness of the sheath  900  may get progressively thicker away from the proximal end  904  toward the distal end  906 . However, in other instances, the wall thickness of the sheath  900  may get progressively thicker away from the distal end  906  toward the proximal end  904 , for example. In some cases, the portion of the sheath  900  having a thinner wall thickness may fully degrade faster than portions of the sheath  900  with a thicker wall thickness. For example, the thinner proximal end  904  may fully degrade over time sooner than the distal end  906 . As such, the thickened and stronger distal end  906  of the sheath  900  may resist radial expansion of the underlying distal portion of the stent longer than the portions of the intermediate portion of the stent underlying the proximal end  904  of the sheath  900 . As the portions of the intermediate portion of the stent are no longer radially constrained by the sheath  900 , those portions of the intermediate portion of the stent are permitted to radially expand and thus axially contract to reduce the axial distance between the proximal anchor  622  and the distal anchor  624 . As shown in  FIG. 9A , in some cases, the sheath  900  may be placed onto the intermediate portion  626  of the bridge device  600  (e.g., surround the intermediate portion of the braided stent, with the flared ends of the stent located on either end of the sheath  900  using methods known in the art. In some cases, the intermediate portion  626  may be restrained in a radially compressed configuration by the sheath  900 . According to various embodiments, the sheath  900  may radially compress, and axially elongate the intermediate portion  626  such that the proximal portion  618  is an initial distance (D 1 ) from the distal portion  620 . Turning to  FIG. 9B , in some instances, the sheath  900 , formed of a biodegradable material, may degrade over time. In this case, because the wall thickness is greater at the distal end  906  than the proximal end  904 , the proximal end  904  may fully degrade before the distal end  906 . In some examples, the degrading of the sheath  900  may allow the exposed portions of the intermediate portion  626  of the bridge device  600  to radially expand and axially contract to decrease the distance between the proximal portion  618  and the distal portion  620  to distance D 2 , less than distance D 1 . At this point, portions of the intermediate portion  626  still underlying the sheath  900  may remain held in a radially contracted state. Additionally, turning to  FIG. 9C , the sheath  900  may continue to degrade over time from one end to the other end. In this case, the sheath  900  may fully degrade over time allowing the intermediate portion  626  to further radially expand and axially contract to decrease the distance between the proximal portion  618  and the distal portion  620  to distance D 3 , less than distance D 2 . 
       FIGS. 10A-10D  show access to and implantation of the esophageal atresia bridge device  600  and sheath  700 . Although the bridge device  600  is depicted with the sheath  700 , it is noted that the sheath  700  may be substituted with another other desired sheath disclosed herein, if desired. Typically, a stent may be delivered by a deployment system or “introducer” (not shown) to the site where it is required. The introducer may enter the body through the patient&#39;s mouth using standard access techniques know in the art. In another technique, the stomach may be punctured with a hollow needle or trocar, for example under ultrasound guidance, to gain access to the patient&#39;s stomach. In this example, the introducer may be advanced to the end  512  of the proximal section  510  of the esophagus  508 . The introducer may then be further advanced to extend from the proximal section  510  to the end  516  of the distal section  514  of the esophagus  508 . In some cases, the introducer may be configured to penetrate through the end  512  of the proximal section  510  and the end  516  of the distal section  514  of the esophagus  508 , such that the introducer passes into the distal section  514  of the esophagus  508 . The introducer may then be manipulated to cause the bridge device  600  and sheath  700  to be released or deployed from the introducer. As shown in  FIG. 10A , the proximal portion  618  may be an initial distance (D 1 ) from the distal portion  620 . In some cases, the proximal anchor  622  may be configured to expand to push against and engage the tissue of a luminal wall of the proximal section  510  of the esophagus  508  near the end  512  of the proximal section  510  to anchor the bridge device  600  to the proximal section  510  of the esophagus  508 . Similarly, the distal anchor  624  may be configured to expand to push against and engage the tissue of a luminal wall of the distal section  514  of the esophagus  508  near the end  516  of the distal section  514  to anchor the bridge device  600  to the distal section  514  of the esophagus  508 . The intermediate portion  626  may extend between the proximal section  510  and the distal section  514  of the esophagus  508 . In some instances, in this position, the bridge device  600  may apply a controlled tension that pulls the proximal section  510  of the esophagus  508  towards the distal section  514  of the esophagus  508  and stretch the esophagus over time. Turning to  FIG. 10B , after the esophagus has had time to stretch, the strings may be pulled to incrementally detach the removable sections of the sheath  700  at the preferential tear lines and tear the removable sections from the sheath  700 . In some examples, the tearing away of the removable sections may allow the intermediate portion  626  to radially expand and axially contract, thus moving the proximal anchor  622  toward the distal anchor  624  to decrease the distance between the proximal portion  618  and the distal portion  620  to distance D 2 . Accordingly, the bridge device  600  may again apply a controlled tension that pulls and stretches the proximal section  510  of the esophagus  508  further towards the distal section  514  of the esophagus  508 . Similarly, turning to  FIG. 10C , after the esophagus has had time to stretch, the strings may be further pulled to detach the removable sections at the preferential tear lines and tear the additional removable sections from the sheath  700 . In some examples, the tearing away of the removable sections may allow the intermediate portion  626  to further radially expand and axially contract, thus moving the proximal anchor  622  further toward the distal anchor  624  to further decrease the distance between the proximal portion  618  and the distal portion  620  to distance D 3 . 
     Turning to  FIG. 10D , when the proximal section  510  is close enough to the distal section  514  of the esophagus  508  the bridge device  600  may be removed and the disconnected portions of the esophagus may be connected. Accordingly, the proximal section  510  may be connected to the distal section  514 , such as with sutures (i.e., the proximal section  510  and/or the distal section  514  have been stretched enough such that any tension administered to connect the proximal section to the distal section will not cause unwanted tearing of the tissue of the proximal section or the distal section). 
       FIGS. 11A-11C  illustrate another example of radial expansion and axial contraction of the intermediate portion  626  as a brace/link (e.g., sheath  1000 ) is removed from the bridge device  600 . The bridge device  600  includes a sheath  1000  surrounding the intermediate portion  626  to radially constrain, and thus axially elongate the intermediate portion of the braided stent while the flanges of the braided stent, forming the proximal and distal anchors  622 / 624  are radially expanded. The sheath  1000  may comprise a filament  1002  having a crocheted or knotted portion  1010  surrounding the intermediate portion  626  and an end portion extending from the stent to be manipulated from exterior of the patient. In the embodiment depicted in  FIG. 11A , the crocheted portion of sheath  1000  surrounding the intermediate portion  626  prevents radial expansion of the underlying intermediate portion. In some cases, the intermediate portion  626  may be restrained in a radially compressed configuration by the sheath  1000 . 
     As shown in  FIG. 11B , the filament  1002  may be pulled to sequentially unravel a portion of the filament and/or release a knot to allow a portion of the stent that is no longer constrained by the filament  1002  to radially expand and axially contract. As the portions of the intermediate portion of the stent are no longer radially constrained by the filament  1002 , those portions of the intermediate portion of the stent are permitted to radially expand and thus axially contract to reduce the axial distance between the proximal anchor  622  and the distal anchor  624 . In some examples, unraveling or untying a portion of the length of the filament  1002  may allow the exposed portions of the intermediate portion  626  of the bridge device  600  to radially expand and axially contract to decrease the distance between the proximal portion  618  and the distal portion  620  to distance D 2 , less than distance D 1 . At this point, portions of the intermediate portion  626  still underlying the sheath  1000  may remain held in a radially contracted state. Additionally, turning to  FIG. 11C , the filament  1002  of the sheath  1000  may continue to be unraveled or untied over time to completely release the intermediate portion  626 . In this case, the sheath  1000  may be fully unraveled or untied over time allowing the intermediate portion  626  to further radially expand and axially contract to decrease the distance between the proximal portion  618  and the distal portion  620  to distance D 3 , less than distance D 2 . Thus, with the proximal anchor  622  expanded in the disconnected proximal portion and the distal anchor  624  expanded in the disconnected distal portion of an esophagus, the distance between the proximal anchor  622  and the distal anchor  624  may be periodically reduced over the course of hours, days, or weeks by unraveling or untying portions of the filament  1002  of the sheath  1000  surrounding the intermediate portion  626  until the proximal anchor  622  has been moved toward the distal anchor  624  a sufficient amount to connect the two disconnected portions of the esophagus together. 
     It should be understood that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of steps without exceeding the scope of the disclosure. This may include, to the extent that it is appropriate, the use of any of the features of one example embodiment being used in other embodiments. The invention&#39;s scope is, of course, defined in the language in which the appended claims are expressed.