Patent Description:
The present disclosure relates generally to medical devices and related methods of preparation and use thereof. More specifically, the present disclosure includes devices useful in endoscopic medical procedures, such as applying a patch to tissue for wound treatment, examples of such devices being found in, e.g., <CIT> or <CIT>.

Various medical procedures are used for treatment of tissue. For example, an endoscopic procedure may be performed to take tissue samples from the gastrointestinal tract or other organ systems for pathological evaluation and/or therapeutic purposes, such as detection and removal of pre-cancerous mucosal tissue or tumors. Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) may be used to separate upper tissue layers to assist in the removal of lesions. A consequence of such medical procedures can be a wound in need of repair and/or protection to allow for tissue repair. Other internal wounds or defects such as, e.g., inflammation, ulcerations, and the like, can result naturally and likewise benefit from therapeutic treatment. Medical devices in the form of bandages and dressings can be prepared from a variety of materials. Applying such dressings to internal tissue, e.g., in an endoscopic procedure, presents particular challenges.

The invention is a medical system defined in the independent claim <NUM> and further explained with reference to <FIG>. Aspects and embodiments of the present disclosure not falling within the claims are provided for illustrative purpose.

The present disclosure includes medical systems comprising a biocompatible patch and methods of use thereof, e.g., methods of delivering a patch to a target site of a patient. For example, the present disclosure includes a medical system that includes an endoscope defining at least one working channel and a patch comprising a biocompatible material. In some examples herein, the system further comprises (a) an instrument comprising a shaft slidably disposed in the working channel, the patch being coupled to, and releasable from, a distal end of the instrument; or (b) a cap coupled to a distal end of the endoscope, the patch covering a distal end of the cap and being releasable from the cap. In some examples, the patch comprises a biomaterial such as chitosan, e.g., chitosan acetate and/or chitosan lactate, extracellular matrix, or a combination thereof. Additionally or alternatively, the patch may have a thickness less than <NUM>, such as less than <NUM> or less than <NUM>. According to some aspects of the present disclosure, a least a portion of the patch comprises an adhesive, optionally a biocompatible and/or bioresorbable adhesive. In some examples, the patch is disposed inside the at least one working channel of the endoscope in a folded or crimped configuration. In other examples, the patch is coupled to an outer surface of the system, such as the outer surface of a cap coupled to the distal end of the endoscope.

In some examples wherein the system comprises the instrument, the distal end of the instrument is rotatable relative to the shaft of the instrument. Alternatively, the distal end of the instrument may be fixed to the shaft, such that rotation of the shaft causes a corresponding rotation of the distal end of the instrument. The distal end may have a cylindrical shape, for example and/or the distal end may include a balloon. In some examples, the distal end of the instrument includes a rim that inhibits or prevents proximal movement of the patch relative to the instrument. For example, the distal end of the instrument may include a cylinder and optionally a rim at or proximate the proximal end of the cylinder, e.g., to inhibit or prevent proximal movement of the patch relative to the cylinder and/or relative to the shaft of the instrument. In some examples, the distal end of the instrument includes a balloon, and the shaft of the instrument comprises an fluid channel in communication with the balloon. The fluid channel may be coupled to a source of fluid such as, e.g., water, air, or other inert gas.

In some examples wherein the system comprises the cap, the patch may be secured to an outer surface of the cap with a band, e.g., a flexible band, such as, e.g., an elastic band. According to some aspects of the present disclosure, the cap includes a ridge on an outer surface of the cap. Additionally or alternatively, the cap may have a frustoconical shape. In some examples, the distal end of the endoscope includes an optical device, and the patch includes an opening aligned with the optical device. Additionally or alternatively, at least a portion of the patch covering the optical device may be translucent. In some examples, the entire patch is translucent.

The endoscope of the system may comprise a single working channel or a plurality of channels. In some examples, the system comprises an auxiliary instrument insertable in one or more of the working channels, e.g., to assist in applying the patch to tissue. Such auxiliary instruments may include, for example, a forceps or other instrument to assist in manipulating the patch relative to the target site. In some examples, the endoscope includes a suction channel in communication with a source of suction and/or a fluid channel in communication with a source of fluid such as air or water.

Also disclosed herein is a method of delivering a patch to a target site of a patient, the method comprising introducing an endoscope into a gastrointestinal tract of a patient, wherein the endoscope includes a patch in a folded or crimped configuration, the patch comprising a biocompatible material; positioning a distal end of the endoscope proximate a target site; and applying the patch to the target site while releasing the patch from the endoscope. The target site may include wounded or diseased tissue, for example, or the target site may correspond to the site of a prior medical procedure. In some examples, the target site includes a laceration in tissue following endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), or tissue biopsy. In some examples, wherein the target site includes an anastomosis, e.g., such that the patch inhibits or prevents leakage. As mentioned above, the patch may comprise a biomaterial such as chitosan, e.g., chitosan acetate and/or chitosan lactate, extracellular matrix, or a combination thereof; and/or the patch may comprise an adhesive, such as, e.g., a biocompatible and/or bioresorbable adhesive.

According to some aspects of the present disclosure, the method further comprises introducing an instrument comprising a shaft into a working channel of the endoscope, the patch being disposed on a distal end of the instrument. For example, applying the patch to the target site may include unrolling the patch from the distal end of the instrument. Further, for example, the distal end of the instrument may include a cylinder, the patch being disposed on a surface of the cylinder, wherein applying the patch to the target site includes rotating the cylinder, e.g., relative to the target site and/or relative to the shaft of the instrument. In at least one example, the cylinder includes a rim that prevents proximal movement of the patch relative to the shaft.

In some examples, the distal end of the instrument includes a balloon, and the shaft of the instrument comprises a fluid channel in communication with the balloon, e.g., for inflation and deflation of the balloon. For example, the patch may be disposed on a surface of the balloon in a folded configuration, the method comprising expanding the balloon to unfold the patch, e.g., to apply the patch to the target site.

As mentioned above, in some examples herein, the endoscope includes a cap coupled to a distal end of the endoscope, the patch covering a distal end of the cap and being releasable from the cap. Thus, for example, applying the patch to the target site may include releasing the patch from the cap, optionally by applying pressure to the patch with a fluid (e.g., air or water) and/or with an instrument via a working channel of the endoscope.

Also provided herein is a method of delivering a patch to a target site of a patient, the method comprising introducing a system comprising an endoscope into a gastrointestinal tract of a patient, wherein the system includes a patch comprising a biocompatible material and one of (a) an instrument comprising a shaft slidably disposed in a working channel of the endoscope, the patch being coupled to, and releasable from, a distal end of the instrument; or (b) a cap coupled to a distal end of the endoscope, the patch covering a distal opening of the cap and being releasable from the cap. The method may further comprise positioning a distal end of the endoscope proximate a target site; and applying the patch to the target site while releasing the patch from the system. In some examples, the patch is coupled to the distal end of the instrument or the cap in a folded or crimped configuration. According to some aspects, releasing the patch includes blowing air or spraying water from a channel of the endoscope onto the patch. In some examples herein, the distal end of the instrument includes a cylinder that comprises a rim, the patch being disposed on a surface of the cylinder distal to the rim.

Particular aspects of the present disclosure are described in greater detail below. The terms and definitions provided herein control, if in conflict with terms and/or definitions incorporated by reference.

As used herein, the terms "comprises," "comprising," or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, composition, article, or apparatus that comprises a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such process, method, composition, article, or apparatus. The term "exemplary" is used in the sense of "example" rather than "ideal.

As used herein, the singular forms "a," "an," and "the" include plural reference unless the context dictates otherwise. The terms "approximately" and "about" refer to being nearly the same as a referenced number or value. As used herein, the terms "approximately" and "about" should be understood to encompass ± <NUM>% of a specified amount or value.

Embodiments of the present disclosure include medical systems and methods for endoscopic delivery of patches for treating tissue. The patches herein may comprise one or more biomaterials (e.g., materials that are biocompatible and/or derived from biological materials), which may be at least partially or completely bioresorbable. For example, upon application to tissue, at least a portion of the patch may dissolve and/or be absorbed by the body over time. In some cases, a portion of the patch may be shed from the site of application to be absorbed or removed by the gastrointestinal system.

The patches herein may serve as a protective layer, a barrier against leaks, a barrier against perforations, a defect closure, a scaffold to promote cell growth, and/or as a hemostatic agent, among other uses. Further, for example, the patches herein may be used to treat various types of tissues, including wounded or diseased tissue, such as burns, lacerations, lesions, inflammation, ulceration, perforations, microperforations, and other sites in need of treatment or repair. The patches herein may be used as an alternative to, or in combination with, sutures, staples, adhesive, and other methods for securing or protecting tissue. In at least one example, the patch may be applied to serve as a hemostatic agent, e.g., to prevent or inhibit bleeding of tissue at a target site.

Exemplary sites to which the patches herein may be applied include, but are not limited to, tissues of the gastrointestinal system such as, e.g., the esophagus, the stomach, the small intestine (e.g., duodenum, jejunum, or ileum), and/or the large intestine (e.g., cecum, colon, rectum, or anal canal). In some examples, an anastomotic resection of the small or large intestine may lead to a risk of leaks between suture lines. The patches herein may be applied to such junctions to serve as a barrier against leakage. In some examples, the patches herein may be applied to a fistula, e.g., an intestinal fistula, to serve as a barrier against leakage of fluid and/or to cover a sac to prevent it from boring into surrounding anatomy Further, for example, the patches herein may be useful for patients that have inflammatory bowel disease (IBD), e.g., applying the patch to a subsidiary disease fistula associated with IBD, wherein the fistula connects intestinal lumens.

In some examples herein, the patch is delivered endoscopically, optionally in conjunction with a medical procedure such as endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), or tissue biopsy. For example, a patch may be delivered endoscopically to a target site to assist the body in regrowing tissue layers removed via ESD or due to ulceration of the mucosal layer. Exemplary biomaterials suitable for the patches herein include, but are not limited to, chitosan, extracellular matrix (ECM), and other biomaterials comprising structural polysaccharides, and combinations thereof.

In some examples herein, the patch comprises chitosan. Chitosan is a linear polysaccharide formed of glucosamine units derived from chitin, the structural component of crustacean exoskeletons. <CHM>
Chitosan is typically prepared by deacetylation of chitin with an alkaline reagent such as sodium hydroxide, yielding a water-soluble material. Chitosan is antimicrobial and has natural bioadhesive properties that allows it to bind to negatively charged surfaces such as mucosal membranes.

The patches herein may comprise chitosan in the form of a salt. For example, salts may be prepared by combining chitosan with a suitable conjugate acid such as acetic acid (forming chitosan acetate) or lactic acid (forming chitosan lactate). Other possible organic acids include, but are not limited to, succinic acid (chitosan succinate), glutamic acid (chitosan glutamate), glycolic acid (chitosan glycolate), and citric acid (chitosan citrate). In an exemplary procedure to prepare a chitosan salt, chitosan is suspended in water at room temperature, followed by the addition of an organic acid (e.g., acetic acid and/or citric acid) to form a gel. The gel is then dried into a film or sheet of desired thickness and dimensions. Without intending to be bound by theory, it is believed that the acid provides for a crosslinked structure that provides sufficient integrity and strength for use as a protective layer when applied to tissue.

In some examples herein, the patch comprises extracellular matrix (ECM). ECM is a complex and naturally-occurring structural material found within tissues that surround and support cells within tissues and organs of living creatures. It makes up the area external to cells and provides physical scaffolding as well as biochemical and biomechanical cues that direct cell function. ECM has been described as the glue that holds cells within a tissue together. ECM typically comprises structural proteins and polysaccharides, as well as various growth factors. ECM materials can provide a generally dynamic structure that adapts to fit the surrounding environment.

The chemical composition of ECM can vary depending on its source, e.g., the type of tissue from which it is derived. For example, ECM may be derived from various types of collagenous tissue. ECM suitable for the present disclosure may be derived from any suitable types of tissue, including, but not limited to, tissues of the spleen, kidney, liver, lung, pancreas, gall bladder, or stomach. Further, the tissue may be obtained from various types of native tissues including, but not limited to, porcine, bovine, ovine, and human tissue.

The patches herein may be formed into any suitable shape and dimensions, e.g., based on the nature of the target tissue site. In some examples, the thickness of the patch may be on the order of millimeters, e.g., ranging from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, from about <NUM> to about <NUM>, or from about <NUM> to about <NUM>, e.g., a thickness of about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, about <NUM>, or about <NUM>. In at least one example, the thickness of the patch is less than <NUM>, less than <NUM>, less than <NUM>, or less than <NUM>. According to some aspects of the present disclosure, the thickness may be uniform. The patches herein may be at least partially translucent in some cases, e.g., allowing light to pass therethrough. The patch may have any shape such as, e.g., square, rectangular, oval, circular, among other possible shapes. In some examples, the patch has a tubular shape, e.g., a thin-walled cylinder, suitable for application to a body lumen such as the esophagus or small or large intestine.

The patches according to the present disclosure may be pliable and bendable. For example, the patch may be formed into a planar film, sheet, or disc capable of being folded, crimped, or otherwise manipulated into a temporarily non-planar configuration within a confined space. Thus, for example, the patch may be folded, curved, or crimped within a confined enclosure such as a sheath or lumen for suitable delivery via an endoscope. Once released, the patch may recover its original planar configuration.

The patch may be substantially dry during delivery to a target site. In some examples herein, the patch may be moistened during delivery or shortly following release from a delivery instrument. For example, the patch may be exposed to water via a fluid channel of an endoscope and/or through contact with bodily fluids or humidity inside the body. When exposed to moisture, the patch may absorb the fluid, causing the patch to swell or expand. For example, the patch, when dry, may be substantially paper-like, and when wet, may take on a more jelly-like consistency. According to some aspects of the present disclosure, moistening the patch may assist in its application to tissue.

In some examples herein, the patch comprises an adhesive, e.g., to assist in applying the patch to tissue and/or maintaining the patch in place after application, and/or to assist in delivery of the patch to the target site. Adhesives suitable for the present disclosure may be natural, e.g., comprising a natural polymer or derived from a natural polymer, or synthetic. Exemplary adhesives include, but are not limited to, gelatin (including, e.g., thrombin/gelatin), fibrin (e.g., fibrin glue), cyanoacrylate, polyethylene glycol (PEG), and albumin (including, e.g., albumin glutaraldehyde). The adhesive may be at least partially resorbable.

The choice of adhesive may be at least partially based on the desired adhesion strength, bioresorbable properties, and/or the nature of the target site to which the patch is being applied. For example, a relatively stronger adhesive may be desired for a patch comprising ECM than for a patch comprising chitosan, which has natural bioadhesive properties. Further, for example, a patch intended for application to a relatively large wound or defect site, may comprise adhesive to further assist with securing the patch to the tissue. Patches according to the present disclosure may comprise adhesive applied to one area or two or more areas, e.g., opposing ends. In some examples, the patch does not include an adhesive.

Medical systems according to the present disclosure may comprise an instrument or cap providing a surface for delivery of a patch comprising a biomaterial or combination of biomaterials as described above and/or elsewhere herein. The systems herein may comprise an endoscope, the patch or patches to be delivered, and/or one or more auxiliary instruments such as, e.g., forceps, an imaging device, or an optical device, etc. The patch or patches may be delivered through the working channel of an endoscope, for example, or with the assistance of a cap coupled to the distal end of an endoscope.

<FIG> shows an exemplary endoscope <NUM> useful for some aspects of the present disclosure, the endoscope <NUM> including a controller <NUM> and a shaft <NUM> extending distally from the controller <NUM> to a distal end <NUM>. The controller <NUM> may have any suitable shape and steering mechanism(s) to allow an operator to navigate the shaft <NUM> through tortuous anatomy and/or towards a site of interest. Accordingly, the shaft <NUM> may be sufficiently flexible to maneuver through different anatomical structures, including portions of the gastrointestinal system.

Any suitable steering mechanism may be used. For example, the steering mechanism may comprise a plurality of steering wires coupling the controller <NUM> to the shaft <NUM>, e.g., to transmit user input from the controller <NUM> to the shaft <NUM> to articulate or deflect the shaft <NUM> along one or more planes. As shown in <FIG>, for example, the controller <NUM> may include one or more actuators, e.g., first and second actuators <NUM>, <NUM> to control deflection of the distal end <NUM> of the shaft <NUM> in two different planes, e.g., along the xy plane via actuator <NUM> and along the yz plane via actuator <NUM>. Concerted movement of the actuators <NUM>, <NUM> may achieve deflection in a plurality of other planes, e.g., providing for <NUM> degree manipulation of the shaft <NUM>. Other steering mechanisms suitable for manipulating the shaft <NUM> may be used, including, but not limited to, other types of mechanical mechanisms and electrical mechanisms. For example, the controller <NUM> may be in electrical communication with various portions of the shaft <NUM>, such that user input at the actuator <NUM>, <NUM> may be converted to electrical signals to control deflection of the distal end <NUM> of the shaft <NUM>.

The shaft <NUM> may include one or more working channels (e.g., working channel <NUM>) in communication with one or more corresponding ports (e.g., port <NUM>) of the controller <NUM>. One or more instruments may be inserted into the working channel <NUM> via the port <NUM> for performing a medical procedure. Exemplary instruments include, but are not limited to, the instruments illustrated in <FIG>, <FIG>, <FIG>, and <FIG> (discussed below), and/or other instruments such as forceps, scissors, scalpels, snares, biopsy brushes, optical devices, or imaging devices. In some examples, the controller <NUM> includes only one port <NUM> or may include two or more ports each in communication with a separate working channel (see, e.g., working channels <NUM> and <NUM> in <FIG>). In some examples, the controller <NUM> may include controls for suction and/or fluids such as a suction valve <NUM> and a fluid valve <NUM>. Thus, for example, the suction valve <NUM> may be in communication with a suction channel of the shaft <NUM> and the fluid valve <NUM> may be in communication with a fluid channel of the shaft <NUM>.

<FIG> illustrate an exemplary system comprising a delivery instrument <NUM> and method of delivering a patch to a target site using the system, according to some aspects of the present disclosure. Specifically, the instrument <NUM> is shown disposed within the working channel <NUM> of an endoscope shaft <NUM> extending to distal end <NUM>. While only one working channel is shown, the method illustrated is equally applicable to an endoscope having a plurality of working channels, one of which houses the instrument <NUM>. Instrument <NUM> includes a shaft <NUM> and a cylinder <NUM> at the distal end of the shaft <NUM>, e.g., similar to a drum or a spool. In some examples, the cross-section of the cylinder <NUM> may be greater than the cross-section of the shaft <NUM>.

According to some aspects of the present disclosure, the cylinder <NUM> is rotatable relative to the shaft <NUM>. For example, the cylinder <NUM> may be free-moving and capable of free rotation relative to the shaft <NUM>, similar to a wheel. Alternatively, the instrument <NUM> may include a mechanism to provide for controlled rotation of the cylinder <NUM>, such as a mechanical lever or electronic switch coupled to the cylinder <NUM> via the shaft and located on a proximal handle of the instrument <NUM> (e.g., the handle being proximal to the port of the endoscope, e.g., port <NUM> of <FIG>). In some examples, the cylinder <NUM> may be fixed relative to the shaft <NUM>, such that rotation of the shaft <NUM> relative to the working channel <NUM> causes corresponding rotation of the cylinder <NUM>.

The dimensions of the cylinder <NUM> may be selected to accommodate a patch <NUM> radially between the outer surface of the cylinder <NUM> and the inner surface of the working channel <NUM>. That is, the patch <NUM> may be wrapped or otherwise disposed on the outer surface of the cylinder <NUM>. The proximal end of the cylinder <NUM> as shown includes a raised surface, e.g., rim <NUM>, to help maintain the position of the patch <NUM> and to prevent proximal movement of the patch <NUM> as the instrument <NUM> slides along the working channel <NUM>. The rim <NUM> is an annular flange having an outer diameter greater than the outer diameter of the cylinder <NUM>. Additionally or alternatively, the surface of the patch <NUM> in contact with the cylinder <NUM> may include an adhesive to secure the patch <NUM> to the instrument <NUM>. The adhesive may be chosen to have a strength sufficient to prevent movement of the patch <NUM> relative to the instrument during delivery while allowing for release of the patch <NUM> upon contact of the patch <NUM> with tissue.

In some examples, the system may include a catheter or sleeve between the instrument <NUM> and the working channel <NUM>. For example, the catheter or sleeve may be disposed radially outside the shaft <NUM> (and the cylinder <NUM> and the patch <NUM> disposed on the cylinder <NUM>), and the inner surface of the working channel <NUM>, e.g., to protect the patch <NUM> during delivery. In such cases, the instrument <NUM> may be preloaded through the protective catheter/sleeve to prevent the patch <NUM> from moving, the instrument <NUM> then moved distally relative to the catheter/sleeve to deploy the patch <NUM>. An adhesive as discussed above may additionally be used, or the catheter/sleeve may be sufficient to maintain the position of the patch <NUM> prior to deployment, without an adhesive.

During delivery, the instrument <NUM> is initially entirely disposed within the working channel <NUM> as shown in <FIG>. Once the shaft <NUM> is proximate the tissue wall <NUM> that includes the target site, the instrument <NUM> may be moved distally to exit the working channel <NUM> as shown in <FIG>. The shaft <NUM> and/or the instrument <NUM> then may be manipulated to allow the patch <NUM> to contact the tissue wall <NUM> at or adjacent to the target site as shown in <FIG>. The portion of the patch <NUM> in contact with the tissue wall <NUM> may attach to the tissue (optionally with the assistance of an adhesive) and release from the surface of the cylinder <NUM> while the remainder of the patch <NUM> remains disposed on the cylinder <NUM>. The cylinder <NUM> then may be rotated about a longitudinal axis of the cylinder <NUM> relative to the tissue wall <NUM>, to apply the remainder of the patch <NUM> to the tissue wall <NUM>, including covering the target site, while releasing (e.g., unwinding) the patch <NUM> from the cylinder <NUM>.

The patch <NUM> may be secured to the tissue wall <NUM> with or without an adhesive. For example, the biomaterial of the patch itself may have adhesive properties and/or may preferentially adhere to the tissue. In some examples, an auxiliary instrument such as a forceps may be used to assist in removing the patch <NUM> from the instrument <NUM> and/or applying the patch <NUM> to the tissue wall <NUM>. See, e.g., <FIG> discussed below.

<FIG> illustrate another exemplary system and method of delivering a patch according to some examples of the present disclosure. Specifically, an instrument <NUM> is shown disposed within the working channel <NUM> of an endoscope shaft <NUM> extending to a distal end <NUM>. Again, only one working channel is shown for illustration purposes, however, the method illustrated is equally applicable to an endoscope having a plurality of working channels. Instrument <NUM> as shown includes a shaft <NUM> that terminates in a distal end <NUM>.

During delivery, the instrument <NUM> is initially entirely disposed within the working channel <NUM> as shown in <FIG>. A patch <NUM> formed as a film or sheet may be disposed on the distal end <NUM> of the shaft <NUM> in a folded, crimped, or collapsed configuration suitable for delivery. For example, the patch <NUM> may be sufficiently pliable to allow the patch <NUM> to be folded in the confined space of the working channel <NUM> but then unfold when released from the working channel <NUM>. As shown in <FIG>, the patch <NUM>, much like an umbrella, extends proximally around the shaft <NUM> with its edges positioned proximal to the distal end <NUM> of the shaft <NUM> and radially between the outer surface of the shaft <NUM> and the inner surface of the working channel <NUM>.

Once the distal end <NUM> of the endoscope shaft <NUM> is proximate the target site, e.g., facing the tissue wall <NUM> that contains the target site as shown in <FIG>, the instrument <NUM> may be moved distally to exit the working channel <NUM>. As the patch <NUM> is released from the working channel <NUM>, the edges of the patch <NUM> may unfold as shown in <FIG>, e.g., the patch <NUM> being sufficiently flexible to adopt the folded configuration inside the working channel <NUM> but recovering its original, unfolded configuration when unconstrained. For example, the edges of the patch <NUM> may unfold or expand when unconfined from the working channel <NUM> to recover the original, unfolded configuration of the patch <NUM>, as shown in <FIG>. Finally, the instrument <NUM> may be further advanced distally to apply the patch to the tissue wall <NUM>, thus covering the target site. In some cases, the patch <NUM> may be sufficiently adhered to the distal end <NUM> of the shaft <NUM>, e.g., with an adhesive to allow the patch <NUM> to remain secured to the instrument <NUM> until it comes into contact with the tissue wall <NUM>. Pressure then may be applied to the patch <NUM> with the shaft <NUM> to secure the patch <NUM> to the tissue wall <NUM>. In some examples, the patch <NUM> may preferentially adhere to the tissue wall <NUM>. In some examples, an auxiliary instrument such as a forceps may be used to assist in removing the patch <NUM> from the instrument <NUM>. Further, in some examples, water and/or positive air pressure may be applied to the patch <NUM> to assist in application to the tissue wall <NUM>. In cases where water is introduced through the working channel <NUM> or another channel of the endoscope, e.g., a fluid channel, the patch <NUM> may absorb the fluid and expand. Moistening the patch <NUM> may enhance its ability to preferentially attach to the tissue wall <NUM>.

<FIG> shows a cap <NUM> that may be used in some methods herein. The cap <NUM> defines a lumen and extends from a proximal end <NUM> to a distal end <NUM> in a generally frustoconical shape. The outer surface of the cap <NUM> includes a raised portion, e.g., ridge <NUM>, which may extend circumferentially along the cap <NUM> in a direction perpendicular or transverse to the length of the cap <NUM>. In some examples, the ridge <NUM> may extend along only a portion of the circumference of the cap <NUM> and/or the ridge <NUM> may be configured as a plurality of raised surfaces generally arranged in a circumferential pattern. According to some aspects of the present disclosure, the cap may be at least partially or completely transparent. In other examples, the cap may be at least partially or completely opaque.

The proximal end <NUM> of the cap <NUM> is configured to fit onto the distal end of an endoscope, e.g., distal end <NUM> of endoscope shaft <NUM> in <FIG>. Any suitable method or features for attaching the cap <NUM> to the endoscope may be used. For example, the cap <NUM> may be formed of a flexible material, e.g., flexible plastic, such that the proximal end <NUM> of the cap <NUM> may surround the distal end of the endoscope in a tight, friction fit. Other possible features include, but are not limited to, tabs or threads. A patch <NUM> is coupled to the distal end <NUM> of the cap <NUM>, such that the patch <NUM> extends across, and covers, the distal opening of the lumen of the cap <NUM>. The patch <NUM> may extend proximally, such that a portion of the patch <NUM> extends over the ridge <NUM> with the edges <NUM> of the patch <NUM> proximal to the ridge <NUM>. A band <NUM> is disposed on the proximal side of the ridge <NUM>, over the patch <NUM> as shown in <FIG>, to secure the patch <NUM> in place and prevent distal movement of the patch <NUM> relative to the cap <NUM>. In some examples, the patch <NUM> may extend further proximal to the ridge <NUM> than shown in <FIG>, e.g., closer to the distal end <NUM> of the endoscope shaft <NUM>. The band <NUM> may be elastic and flexible, e.g., comprising a material such as plastic or silicone. In some examples, the endoscope may include an optical device <NUM> to assist in viewing the target site during delivery. In some examples, the portion of the patch <NUM> that overlays the optical device <NUM> may be cut to allow a window through which a user may see the tissue wall <NUM> via the optical device <NUM>.

To deliver the patch <NUM> to the target site of a tissue wall <NUM>, the cap <NUM> may be coupled to the distal end <NUM> of the endoscope with the patch <NUM> and band <NUM> attached as described above. Once the distal end <NUM> is proximate the target site, e.g., facing the tissue wall <NUM> that contains the target site as shown in <FIG>, the endoscope may be moved distally to press the patch <NUM> against the tissue wall <NUM>, such that the patch <NUM> covers all or some of the target site. In order to release the patch <NUM> from the cap <NUM>, the band <NUM> may be cut so that it uncovers the patch <NUM>. For example, the band <NUM> may be attached to a mechanism of deployment affixed temporarily, for the purposes of the procedure, to the working channel, handle, or other portion of the endoscope, such that a user may actuate/tighten the wire to cut the band <NUM>, e.g., via a suitable actuator (e.g., knob, wheel, gear, button, pull-tab, etc.) attached or otherwise coupled to the wire. In some examples, the wire may be tied to the band and extend distally alongside the endoscope shaft or through the a working channel <NUM> of the endoscope, e.g., the wire passing through a hole in the cap <NUM> or an opening between the cap <NUM> and the distal end <NUM> of the endoscope. A portion of the band <NUM> may be tethered to the cap <NUM> and/or the endoscope to avoid loss of the band <NUM> during delivery of the patch <NUM>.

In some cases, the pressure applied to the patch <NUM> with the endoscope in combination with release of the band <NUM> may be sufficient to entirely release the patch <NUM> from the endoscope and cap <NUM>. Additionally or alternatively, insufflation and/or water pressure may be used to decouple the patch <NUM> from the cap <NUM> by blowing air or spraying water from a fluid channel of the endoscope against the side of the patch <NUM> facing the endoscope.

<FIG> illustrate yet another exemplary system and method according to some aspects of the present disclosure. Specifically, an instrument <NUM> is shown disposed within the working channel <NUM> of an endoscope shaft <NUM> extending to a distal end <NUM>. Only one working channel is shown for illustration purposes, however, the method illustrated is equally applicable to an endoscope having a plurality of working channels. Instrument <NUM> includes a shaft <NUM> coupled to an inflatable device, e.g., balloon <NUM>. The shaft <NUM> may include a fluid channel, e.g., coupled to a source of fluid such as air or water, in communication with the balloon <NUM> for inflation and deflation.

A patch <NUM> is disposed on the outer surface of the balloon <NUM>, e.g., in a folded or crimped state, while the balloon <NUM> is deflated. The folds may allow for the patch <NUM> to accommodate expansion of the balloon <NUM>. In some examples, the patch <NUM> may have a tubular shape and completely surround the balloon <NUM>, as shown. In other examples, the patch <NUM> may be configured as a film or sheet disposed on only a portion of the circumference of the balloon <NUM>.

During delivery, the endoscope is inserted into a body lumen adjacent to a tissue wall <NUM> that includes a target site <NUM>, such as a lesion or other wound. The instrument <NUM> is initially entirely disposed within the working channel <NUM> as shown in <FIG>. Once the shaft <NUM> of the endoscope is proximate the target site <NUM>, the instrument <NUM> may be moved distally to exit the working channel <NUM>, as shown in <FIG>. The instrument <NUM> is advanced, or the endoscope is retracted or withdrawn, such that the balloon <NUM> and patch <NUM> disposed thereon, are outside the working channel <NUM>, as shown in <FIG>. Finally, the balloon <NUM> is inflated, thus expanding and unfolding the patch <NUM> such that the patch <NUM> contacts the tissue wall <NUM> and the target site <NUM>, as shown in <FIG>. Upon contacting the tissue, the patch <NUM> may preferentially attach to the tissue and release from the balloon <NUM>. In some examples, the patch <NUM> may be secured to the balloon <NUM> with an adhesive with sufficient strength to prevent movement of the patch <NUM> relative to the balloon <NUM> during delivery while allowing for release of the patch <NUM> upon contact with the tissue wall <NUM>. Once the patch <NUM> is released, the balloon <NUM> may be deflated and the instrument <NUM> and endoscope withdrawn from the body lumen.

<FIG> illustrate another example of applying a patch <NUM> to a tissue wall <NUM> of a patient. For example, the tissue wall <NUM> may be part of the patient's gastrointestinal system, such as the esophagus, the stomach, the small intestine (e.g., duodenum, jejunum, or ileum), or the colon. The tissue wall <NUM> includes a target site <NUM> such as a cut, laceration, or other wound. For example, the target site <NUM> may result from torn or cut tissue, e.g., due to an injury or as part of a medical procedure, such as a biopsy.

The patch <NUM> may have opposing ends, labeled 880a and 880b, that are applied to areas on either side of the target site <NUM>, and a middle portion 880c between the two ends. The first end 880a may be applied and secured to the tissue wall <NUM> adjacent to the target site <NUM>, e.g., via natural adhesive properties of the patch <NUM> or a suitable adhesive applied as discussed above. The patch <NUM> then may be manipulated to apply the second end 880b to the tissue wall <NUM> on the opposite side of the target site <NUM>, such that the patch <NUM> acts to bring the sides of the target site <NUM> together to close the wound. The patch <NUM> therefore may have enough structural integrity to withstand manipulation and to secure the sides of the wound together. In some examples, at least a portion of the patch <NUM> may stretch to facilitate placement and application of the patch <NUM> to the target site <NUM>. For example, middle portion 880c may be sufficiently resilient to allow for application of the first and second ends 880a, 880b on opposing sides of the target site <NUM> and then spring back to its original shape to bring the sides of target site <NUM> together. Each end 880a, 880b may include a suitable adhesive to promote and facilitate attachment of the patch <NUM> to the tissue wall <NUM>. In some examples, the middle portion 880c of the patch <NUM> does not include adhesive.

The patch <NUM> may be delivered to the target site <NUM> via any suitable method, including, for example, the methods illustrated in the accompanying figures. For example, the patch <NUM> may be delivered using the system illustrated in <FIG>, e.g., via an endoscope <NUM> that may include any of the features of endoscope <NUM> of <FIG>. The endoscope shaft <NUM> includes a working channel <NUM> that accommodates a delivery instrument <NUM> equipped with the patch <NUM>, wherein the instrument <NUM> may include any of the features of instrument <NUM> of <FIG>. The endoscope <NUM> includes a second working channel <NUM> that accommodates a forceps <NUM>. The patch <NUM> may be released from the instrument <NUM> by rotating the distal end <NUM> of instrument <NUM> relative to the shaft <NUM>. For example, the first end 880a may be pressed to a portion of the tissue <NUM> adjacent to the target site <NUM> with sufficient pressure so that it adheres to the tissue <NUM>. Additional rotation may release the remaining portion of the patch <NUM> from the distal end <NUM>, including second end 880b. Finally, the forceps <NUM> may be used to grasp the second end 880b of the patch <NUM> and apply it to the portion of the tissue <NUM> adjacent to the opposite side of the target site <NUM>. The instrument <NUM> optionally may be withdrawn into the working channel <NUM> to provide working space for the forceps <NUM>. In some examples, the endoscope <NUM> may include only one working channel <NUM>, the instrument <NUM> being withdrawn from the working channel <NUM> before introducing the forceps <NUM> into the same working channel <NUM>.

Claim 1:
A medical system comprising:
an endoscope (<NUM>) defining at least one working channel (<NUM>);
a patch (<NUM>) comprising a biocompatible material; and
a cap (<NUM>) coupled to a distal end (<NUM>) of the endoscope, the patch covering a distal end of the cap and being releasable from the cap,
characterized in that
a proximal end (<NUM>) of the cap (<NUM>) is fitted onto the distal end of the endoscope.