Patent Description:
This section also provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

Short bowel syndrome (SBS) is a condition in which congenital, infectious, or traumatic injuries result in loss of bowel length and this decreased intestinal surface area is unable to absorb sufficient nutrients to sustain life. Parenteral nutrition (PN), in which calories and nutrients are delivered intravenously, is life sustaining but associated with many complications including infection, liver disease, and even death. Current treatments for SBS are inadequate with cure rates reaching only <NUM>-<NUM>%.

The principles of the present teachings provide a mechanotransductive bowel extender device that can be used to correct short bowel syndrome by applying tension to the bowel tissue which, via the process of mechanotransduction, grows in length in response to the applied tension. Such a device is placed within the small bowel and applies tension over a period of several days or weeks by attaching to the lumen of the bowel at two different locations and moving those two points apart, thereby stretching the tissue.

A mechanotransductive bowel extender device according to the preamble of claim <NUM> is known from <CIT>. Further reference is made to <CIT> which discloses a similar device.

In view of this it is an object of the invention to disclose an improved mechanotransductive bowel extender device that facilitates application of the device even while not yet being in the final position of application.

According to the invention this object is solved by a mechanotransductive bowel extender device according to claim <NUM>. Preferred embodiments are subject of the dependent claims.

Numerous specific details are set forth such as examples of specific components and devices, to provide a thorough understanding of embodiments of the present disclosure.

The processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance.

Thus, the example term "below' can encompass both an orientation of above and below.

According to the principles of the present teachings, as illustrated in <FIG>, a mechanotransductive bowel extender device <NUM> is disclosed that can be used to correct short bowel syndrome by applying tension to the bowel tissue <NUM> (FIGS. 5A-5C) which, via the process of mechanotransduction, grows in length in response to the applied tension. Bowel extender device <NUM> is placed within the small bowel and applies tension over a period of time, typically on the order of several days or weeks, by attaching to the bowel lumen <NUM> at two different locations (generally denoted at regions X and Y and moving those two points apart, thereby stretching the bowel tissue <NUM>.

With particular reference to <FIG>, in some embodiments, bowel extender device <NUM> is particular configured to permit the delivery of a medically relevant liquid at a treatment location via bowel extender device <NUM>. In some embodiments, bowel extender device <NUM> can comprise a pair of engagement features <NUM>, an elongation system <NUM>, a medically relevant liquid delivery system <NUM>, an optional atraumatic tip <NUM>, and catheter structure <NUM>. Generally, bowel extender device <NUM> is sized and configured to be inserted within the bowel <NUM> of a mammal, typically human being, for treatment of short bowel syndrome via mechanotransduction.

In some embodiments, engagement features <NUM> can comprise a fenestrated attachment system <NUM> each spaced apart from the other to define a distance therebetween that is variable in response to actuation of elongation system <NUM> (see FIGS. 5B and 5C). More particularly, upon actuation of elongation system <NUM>, a driving force is imparted between the pair of fenestrated mesh textured balloon attachments <NUM> that imparts a tensile force upon the bowel to encourage bowel growth. In some embodiments, balloon attachment <NUM> is a toroidal structure that is fixed outside the catheter structure.

In some embodiments, to facilitate the selective attachment and detachment of bowel extender device <NUM> from the bowel lumen or other hollow member <NUM>, a fenestrated attachment system <NUM>, such as an endduminal balloon attachment mechanism, is provided that employs a fenestrated decoupling system <NUM>. The fenestrated attachment system <NUM> is placed within the bowel lumen or other hollow organ member <NUM> and is capable of radially expanding, thereby coupling with the inner luminal surface <NUM> of the bowel or other interior surface <NUM> of the hollow member <NUM>, to allow transfer of longitudinal tensile loads to the bowel wall or hollow member <NUM> and/or permit translation therethrough.

In some embodiments, fenestrated attachment system <NUM> comprises an expanding device <NUM> (e.g. balloon) disposed on at least one end <NUM>, <NUM>. However, in most embodiments, a pair of expanding devices or balloons <NUM> will be used. In some embodiments, expanding device <NUM> is enlargeable between a deflated position (first size position) and an inflated position (second size position), whereby the inflated position is sufficiently large to permit mechanical engagement with the interior surface <NUM> of the hollow member <NUM> (i.e. bowel lumen). It should be understood that in some embodiments, the size of the inflated position must be sufficiently large to further accommodate any resultant enlargement of the hollow member in response to application of the inflation force. Likewise, it should be understood that in some embodiments, the size of the deflated position must be sufficiently smaller to permit disengagement of fenestrated attachment system <NUM> from the interior surface <NUM> of hollow member <NUM>, at least when used in conjunction with fenestrated decoupling system <NUM>.

In some embodiments, fenestrated attachment system <NUM> further comprises a friction enhancement or texture <NUM>. In some embodiments, friction enhancement <NUM> can comprise application of an abrasive texture generally surrounding expanding device <NUM> that is capable of expanding during inflation of expanding device <NUM> and retracting during deflation of expanding device <NUM>. In some embodiments, it has been found that an open-cell matrix, such as a <NUM>, Scotch-Brite Dobie, is useful. In some embodiments, friction enhancement <NUM> can comprise a fabric material structure surrounding expanding device <NUM>. The fabric material structure can include one or more fibers knitted into a series of interlocked loops such that the knitted fabric can expand and contract along with expanding device <NUM>. The loops can engage the interior surface <NUM> of the hollow member <NUM>. In some embodiments, the fibers can include a flat ribbon such that the edges of the flat ribbon engage with the interior surface of the hollow member. In some embodiments, the friction enhancement <NUM> can include a plurality of bristles fixed to expanding device <NUM> engageable with the interior surface of the hollow member. In some embodiments, the friction enhancement <NUM> can include a plurality of loops fixed to the expanding member which engage the interior surface of the hollow member. Moreover, in some embodiments, the friction enhancement <NUM> comprises a plurality of scales, suction cups, and/or ridges fixed to the expanding device <NUM> which engage with the interior surface of the hollow member.

However, it was found that in some applications, friction enhancement <NUM> may not reliably disengage from interior surface <NUM> of hollow member <NUM> even after expanding device <NUM> is deflated and friction enhancement <NUM> is in the retracted position. Failure to disengage from interior surface <NUM> may inhibit further insertion, removal, and/or purposeful repositioning of the device. Accordingly, fenestrated decoupling system <NUM> can be employed about friction enhancement <NUM> to encourage disengagement of friction enhancement <NUM> from interior surface <NUM> upon deflation of expanding device <NUM>. In some embodiments, fenestrated decoupling system <NUM> can comprise a plurality of bands <NUM> being disposed longitudinally along friction enhancement <NUM> at radial positions radially thereabout. In some embodiments, the plurality of bands <NUM> are comprises of elastic bands, which can be made of a monofilament material. The plurality of bands <NUM> can be retained by a pair of ring members disposed at opposing sides of fenestrated attachment system <NUM> that permit the plurality of bands <NUM> to pass there over and be captured and retained within fenestrated attachment system <NUM>.

During operation, in some embodiments, fenestrated decoupling system <NUM> is operable to expand to accommodate inflation of expanding device <NUM> and, by association, enlarge friction enhancement <NUM>, thereby permitting friction enhancement <NUM> to engage the interior surface <NUM> of hollow member <NUM>. Once friction enhancement <NUM> is operably engaged with interior surface <NUM>, elongation system <NUM> of bowel extender device <NUM> can be actuated. Conversely, once actuation is complete, expanding device <NUM> can be deflated and, by association, retract friction enhancement <NUM>. This permits friction enhancement <NUM> to retract. The plurality of bands <NUM> of fenestrated decoupling system <NUM> can similarly retract. Retraction of friction enhancement <NUM> to a size smaller than retraction of the plurality of bands <NUM> of fenestrated decoupling system <NUM> can permit the plurality of bands <NUM> to disengage interior surface <NUM> of hollow member <NUM> from friction enhancement <NUM>, thereby permitting insertion, removal, and purposeful repositioning of the device.

In some embodiments, device <NUM> includes a catheter structure extending from device <NUM> situated within the bowel to the exterior of the body through either a natural or surgically created body orifice to the outside of the body. This catheter enables the delivery of air and or fluids to inflate expanding device <NUM> and actuate elongation system <NUM>. When inflated, expanding devices <NUM> contact the inner lumen <NUM> of the bowel <NUM>, temporarily attaching to the bowel <NUM>. The elongation system <NUM>, such as a hydraulic piston, is then extended, separating expanding devices <NUM> (e.g. increasing a distance therebetween), thereby applying tension to the bowel. The device <NUM> is left in this position for a period of several hours or days over which the bowel tissue responds to the applied tension by growing, gradually relieving the tension. The balloons <NUM> are then deflated, detaching from the newly grown bowel, and the hydraulic piston <NUM> is retracted, bringing the device <NUM> back to its initial configuration. This process can be repeated to continually grow additional bowel.

According to the principles of the present teachings, elongation system <NUM> can comprise any one of a number of actuation methods, including hydraulic, pneumatic, electric motor, ratchets driven by shape memory alloy wires, and manual pushing. <FIG> illustrates a device wherein the two balloons <NUM>, distal and proximal, are each mounted to concentric inner and outer catheters, respectively, where the inner catheter can be manually pushed forward relative to the outer catheter, increasing the distance between the two balloons. <FIG> illustrates a schematic of the present teachings wherein distal and proximal balloon inflation ports are connect through channels in the inner and outer catheters, respectively, to enable the injection and removal of air or fluid to inflate and deflate the balloons <NUM>.

According to the principles of the present teachings, atraumatic tip <NUM> is employed to provide progressive tapering or reduction in the amount of stiffness along at least a portion of the length of the device <NUM>. More particularly, the stiffness of a proximal end <NUM> of atraumatic tip <NUM> that is adjacent an end of elongation system <NUM> and/or fenestrated attachment system <NUM> is generally greater than a distal end <NUM> of atraumatic tip <NUM>. In some embodiments, this stiffness reduction along the length of atraumatic tip <NUM> can be linear, exponential, or define a non-linear predetermined reduction. Atraumatic tip <NUM> can comprise one or more internal flexure members and an optional covering or sheath disposed about flexure members.

As part of the bowel extension process, it may be desired to deliver and/or evacuate various forms of medication or other medically relevant substances in liquid form to the bowel lumen <NUM>. The term "medically relevant liquid" will be used herein to denote any liquid that may be used for therapeutic and/or operational purposes that is intended to be introduced to tissue for medical therapy and/or device operation. For example, it is currently unknown whether any pain will be caused by the applied tension, but in the case that it is, local topical pain medication, such as viscous lidocaine, delivered directly to the tensioned bowel tissue would be significantly more effective and safe than systemic narcotics which are typically avoided if possible to prevent systemic side effects and tolerance. Beyond therapeutics, barium sulfate or other radiographic contrast agents could be injected into the flush port to both monitor device location and insure proper device attachment.

Furthermore, when moving the device <NUM> within the bowel <NUM> for growth, it needs to slide within the bowel <NUM> without bunching the newly grown bowel tissue. The attachment balloons <NUM>, which may induce some friction drag on the bowel lumen <NUM> when deflated, would slide more easily with use of a lubricating medically relevant liquid delivered around the device <NUM>. Such lubrication would also be useful to enable smooth insertion, repositioning, and removal of the device <NUM> from the bowel <NUM>.

Moreover, according to the principles of the present teachings, delivery of substances around the device <NUM> within the bowel <NUM> may include the synergistic application of GLP-<NUM>, growth hormone, or even glutamine (a well-known enterocyte fuel) to improved bowel growth in combination with bowel stretching. GLP-<NUM> (Gattex™) delivered systemically, has been demonstrated to increase bowel length in short bowel patients. Unfortunately, while systemic delivery is effective at inducing some bowel growth, it has significant side effects including nausea, vomiting, bloating, headache, and irritation at the subcutaneous injection site. Moreover, it is also very expensive, costing $<NUM>,<NUM> a year per patient treated.

However, according to the present teachings, any one or more medically relevant liquids can be used: local pain and/or inflammatory medication, such as low dose lidocaine, acetaminophen (Tylenol), ibuprofen (Motrin), and the like; growth factors, such as Teduglutide/GLP2 (Gattex); locally applied steroids, such as budesonide for inflammatory bowel disease use; local applied chemotherapy, such as for small bowel tumors; and any liquid enteral medication, such as a jejunostomy tube. In some embodiments, evacuation of the medically relevant liquid may be beneficial, such as when employing steroids or chemotherapeutic agents.

It has previously been demonstrated that GLP-<NUM>, applied systemically in conjunction with mechanotransductive treatment using osmotic pressure to inflate the bowel, creating tension on the bowel wall (without the use of a specific device), has a synergistic effect, where the growth factor enhances the mechanotransductive action such that the combination would induce more growth than either separately. Using a bowel extender device in conjunction with systemic application GLP-<NUM> would have such a synergistic effect. To mitigate the side effects and injection site problems with the systemic use of GLP-<NUM>, GLP-<NUM> can be solely delivered locally to the tensioned bowel tissue, reducing the overall effects on the rest of the body and reducing the total amount of growth factor required.

All of these potential applications call for the delivery of medical substances in liquid form locally to the bowel tissue <NUM> surrounding the bowel extender device <NUM>. To this end, as illustrated in <FIG> and 5A-5C, device <NUM> can comprise medically relevant liquid delivery system <NUM> having an injection line <NUM> extending through at least one expanding device <NUM> to one or more ports <NUM> disposed between expanding devices <NUM> according to some embodiments. Ports <NUM> can be in fluid communication with a volume <NUM> (FIG. 5A) formed within bowel <NUM> defined by bowel lumen <NUM> and expanding devices <NUM>. When expanding devices <NUM> are in the inflated position whereby they engage, contact, and generally seal against lumen <NUM>, volume <NUM> is a contained volume to which medically relevant liquid can be introduced from a source external to the body through injection line <NUM> and one or more ports <NUM> thereto. In this way, medically relevant liquids are introduced and contained at a treatment location for direct treatment. Injection line <NUM>, being internal to device <NUM>, provides unobstructed access to volume <NUM> without requiring a separate line to be introduced in a space between expanding device <NUM> and lumen <NUM>, which would result in reduced contact between expanding device <NUM> and lumen <NUM> negatively effecting mechanotransductive treatment.

In some embodiments, injection line <NUM> can extend along a length of catheter structure <NUM> and be operably coupled to a fluid system <NUM>, such as a fluid source <NUM>, pump <NUM>, distribution manifold <NUM>, and/or syringe <NUM>, through which fluids and medically relevant liquids can be delivered. In this way, introduction of medically relevant liquid can be automated (via pump <NUM> and distribution manifold <NUM>) and/or manual (via syringe <NUM>).

In some embodiments, injection ports <NUM> can be disposed at a plurality of positions along device <NUM>. More particularly, in some embodiments, ports <NUM> can be disposed along linear positions generally equidistant between expanding devices <NUM>. In some embodiments, ports <NUM> can be radially disposed about device <NUM> to facilitate even application of medically relevant liquid within volume <NUM>. It should be noted that in some embodiments, ports <NUM> can be disposed to outboard locations relative to expanding devices <NUM>-that is, positions not within volume <NUM>-to facilitate movement of device <NUM> within bowel <NUM>. In some embodiments, balloon <NUM> is a toroidal structure that is fixed outside the catheter <NUM> and the injection line <NUM> runs completely under the balloon <NUM> to the end of the catheter <NUM> and out end caps formed on ends of balloon <NUM>. It should be understood that injection line <NUM> can be disposed in any one of a number of configurations, including but not limited to through an inner portion of catheter <NUM> (see <FIG>), through an outer portion of catheter <NUM>, or between several catheters of catheter structure <NUM>.

Thus, when medically relevant liquid is injected into an exterior injection port, it will emanate from the multiple corresponding exit ports and come into contact with the interior of the bowel lumen surrounding the device. In this manner, medically relevant liquids can be delivered directly to the bowel tissue surrounding the device. This delivery of medically relevant liquids is independent of the state of operation of the extender device, and can be accomplished both while the device is applying tension to the bowel and while it is not.

In addition, it may be desired to enhance the even application of the medically relevant liquids to the bowel tissue and to improve the absorption of the medically relevant liquids into the tissue. This can be accomplished through the use of the bowel extender to mechanically spread the medically relevant liquid and rub it into the tissue by alternatingly extending and retracting the bowel extender device with the balloon attachments deflated such that the deflated attachment portions of the device slide back and forth within the bowel lumen evenly distributing the applied medically relevant liquid to the tissue.

These features also provide the ability to remove or evacuate medically relevant liquids and other materials from the bowel through the same channels. This could be useful for relieving pressure caused by possible bowel occlusion induced by the presence of the device.

Claim 1:
A mechanotransductive bowel extender device comprising:
an elongation system (<NUM>) being operable to apply a tensile force to a bowel (<NUM>) of a patient, the tensile force being configured to encourage growth of the bowel (<NUM>) through mechanotransductive treatment;
an engagement system having a pair of attachment mechanisms (<NUM>) disposed on opposing ends of the elongation system (<NUM>), said pair of attachment mechanisms (<NUM>) being configured to couple to the bowel (<NUM>) and transmit the tensile force to the bowel (<NUM>);
characterized in that a liquid delivery system (<NUM>) is operably coupled with the elongation system (<NUM>) to locally apply a medically relevant liquid to the bowel (<NUM>).