Devices, systems and methods for tissue retraction

Abstract

A tissue retraction device is disclosed having a segment defined along a limited extent of the circumference of the tissue retraction device that is more flexible than a peripheral region of the tissue retraction device. The tissue retraction device is operable to bend along the more flexible segment in a direction generally opposite the more flexible segment of the tissue retraction device. The tissue retraction device may be formed from one or more flexible tubular elements having a flexible segment along a limited extent of the circumference of the one or more tubular elements. The tissue retraction system may be configured to provide an actuation medium, such as an inflation medium, to the tissue retraction device to control movement of the tissue retraction device. The tissue retraction system may include one or more flexible tubular elements, the distal ends of which form the tissue retraction device.

Description

[Technical field]

[0001] The present disclosure relates generally to the field of devices, systems, and methods for applying traction to tissue. More specifically, the present disclosure relates to devices, systems, and methods for applying traction to tissue in controllable directions, such as more than one direction. [Background technology]

[0002] Various endoscopic surgical procedures require manipulation of various anatomical structures. Several procedures, such as endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), and peroral endoscopic myotomy (POEM), allow for minimally invasive endoscopic removal of benign and early malignant lesions, such as in the gastrointestinal (GI) tract. Minimally invasive surgical procedures such as these typically allow for faster recovery compared to open or laparoscopic procedures. However, because such procedures are minimally invasive, there is limited space to manipulate within the body, and such procedures typically require highly specialized skills. In procedures involving the resection of tissue, one of the greatest factors of time and complexity is the management of the tissue to be resected. Separated pieces of tissue can obstruct the view by falling onto the endoscope, blocking the view of the camera, affecting the movement of instruments used during the procedure, and creating obstacles to reaching all areas and depths of the target tissue to be resected. Various solutions have been developed to lift the resected (and often sagging) tissue mass, thereby clearing a path for viewing and manipulation of medical tools and devices. However, positioning of elements used in such solutions can be difficult, especially in space-limited environments. Elements used in such solutions may also require separate medical tools from those used to perform the procedure, which may even require separate working channels of the endoscope, thereby increasing the size and / or complexity of the endoscope. Alternative solutions for lifting tissue during procedures that reduce the cost, complexity, and cognitive load presented by currently available solutions would be welcome. Summary of the Invention

[0003] This Summary of the disclosure is provided to aid in understanding, as those skilled in the art will appreciate that each of the various aspects and features of the disclosure can be advantageously used separately in some instances, or in combination with other aspects and features of the disclosure in other instances. The inclusion or exclusion of an element, component, or the like in this Summary is not intended to limit the scope of the claimed subject matter.

[0004] In accordance with various principles of the present disclosure, a tissue retraction system includes a tissue retraction device and one or more elongate elements operably coupled to the tissue retraction device for actuating bending of the tissue retraction device, in some embodiments, a longitudinal circumferential region of the tissue retraction device is more flexible than a peripheral region of the tissue retraction device such that actuation of the tissue retraction device causes bending along a more flexible region toward a less flexible region.

[0005] In some embodiments, the tissue retraction device is formed by a distal extent of one or more elongate elements extending a length proximal to a distal end of the one or more elongate elements. In some embodiments, at least one of the elongate elements is a flexible tubular element. In some embodiments, the at least one flexible tubular element has a sealed distal end. In some embodiments, the tissue retraction system further comprises an actuation mechanism operably coupled to the one or more elongate elements to cause bending of the tissue retraction device. In some embodiments, the distal extent of the at least one flexible tubular element forms a flexible tubular element of the tissue retraction device, a longitudinal circumferential region of the tissue retraction device is formed along the distal region of the at least one flexible tubular element and is more expandable than a peripheral region of the tissue retraction device, and the actuation mechanism delivers an inflation medium to the tissue retraction device through the at least one flexible tubular element to expand the longitudinal circumferential region of the tissue retraction device relative to the peripheral region of the tissue retraction device to bend the tissue retraction device.

[0006] In some embodiments, the tissue retraction system further includes an actuation mechanism operably coupled to one or more elongate elements for causing bending of the tissue retraction device. In some embodiments, stiffening elements are applied along limited regions along the periphery of the tissue retraction device, such that the peripheral region is relatively more flexible.

[0007] In some embodiments, the one or more elongate elements include a flexible tubular element having a sealed distal end, the tissue retraction device is formed by a distal extent of the flexible tubular element extending a length proximal to the sealed distal end of the flexible tubular element, and the tissue retraction device is directionally expandable upon application of an expansion medium to expand a highly flexible region of the tissue retraction device and bend the tissue retraction device toward the stiffening element.

[0008] In accordance with various principles of the present disclosure, a tissue retraction device has an elongate cylindrical body extending along a longitudinal axis and having a distal end, a proximal end, and a flexible segment extending along only a portion of the circumference of the cylindrical body between the distal and proximal ends, hi some aspects, the flexible segment is more flexible than the circumference of the cylindrical body to facilitate bending of the cylindrical body along the flexible segment.

[0009] In some embodiments, the cylindrical body is tubular and expandable, and the flexible segments are more extensible than the surrounding portions of the cylindrical body, such that expansion of the tubular cylindrical body causes expansion and bending of the flexible segments toward the opposite, less extensible side of the cylindrical body.

[0010] In some embodiments, the flexible segment extends only along a limited extent along the longitudinal axis of the cylindrical body. In some embodiments, the cylindrical body is formed of a flexible material and the stiffening element is applied to a limited extent around the circumference of the flexible cylindrical body, and a flexible segment is defined opposite the stiffening element.

[0011] In some embodiments, the cylindrical body is a distal segment of a flexible tubular element of the tissue retraction system. In some aspects, the method of applying traction with a tissue retraction device includes actuating the tissue retraction device to bend along a flexible region of a gripping end of the tissue retraction device that is more flexible than a surrounding region toward a region of the tissue retraction device opposite the flexible region to cause the tissue retraction device to apply traction via its gripping end. In some aspects, the tissue retraction device is tubular, and the method further includes actuating the tissue retraction device by delivering an inflation medium to a lumen defined within the tissue retraction device to expand a flexible segment of the tissue retraction device relative to the surrounding region to cause the tissue retraction device to bend in a direction generally opposite the flexible segment.

[0012] In some embodiments, the tissue retraction device includes a plurality of flexible tubular elements joined together along a common joint region, a flexible segment of the tissue retraction device formed along each segment of the plurality of flexible tubular elements generally opposite the common joint region, and the method includes selectively actuating one or more of the plurality of flexible tubular elements of the tissue retraction device to control bending of the actuated flexible tubular elements toward the common joint region and to control bending of the tissue retraction device in more than one direction. In some embodiments, each flexible tubular element is formed by a distal segment of the flexible tubular elements forming a tissue retraction system, each flexible tubular element having a lumen for delivering inflation medium to the tissue retraction device and a sealed distal end, and the method further includes selectively delivering inflation medium through one or more of the flexible tubular elements to control bending of the tissue retraction device in more than one direction.

[0013] In some embodiments, the flexible tubular element of the tissue retraction device is formed along a distal segment of the flexible tubular element having a lumen for delivering an inflation medium to the tissue retraction device and a sealed distal end, and a stiffening element is applied along a limited region of the circumference of the flexible tubular element of the tissue retraction device such that the peripheral region defines a highly flexible region of the tissue retraction device, and the method further includes selectively delivering an inflation medium through the flexible tubular element to control bending of the tissue retraction device into the stiffening element.

[0014] In some embodiments, a method of applying traction to a target tissue includes engaging a first tissue engaging feature of a tissue retraction device with the target tissue, engaging a second tissue engaging feature of the tissue retraction device with tissue away from the target tissue, and actuating the tissue retraction device to bend along a flexible segment thereof that is more flexible than a surrounding region toward a region of the tissue retraction device opposite the flexible region to cause the tissue retraction device to apply traction to the target tissue.

[0015] In some embodiments, the tissue retraction device is tubular, and the method further includes actuating the tissue retraction device by delivering an inflation medium to a lumen defined within the tissue retraction device to expand a flexible segment of the tissue retraction device relative to the surrounding region and bend the tissue retraction device in a direction generally opposite the flexible segment. In some embodiments, the tissue retraction device includes a plurality of flexible tubular elements joined together along a common joint region, the flexible segment of the tissue retraction device being formed along a segment of each of the plurality of flexible tubular elements generally opposite the common joint region, and the method further includes selectively actuating one or more of the plurality of flexible tubular elements of the tissue retraction device to control bending of the actuated flexible tubular element toward the common joint region and to control bending of the tissue retraction device in more than one direction. In some embodiments, each flexible tubular element is formed by a distal segment of a flexible tubular element forming a tissue retraction system, each flexible tubular element having a lumen for delivering an inflation medium to the tissue retraction device and a sealed distal end, the method further comprising selectively delivering inflation medium through one or more of the flexible tubular elements to control bending of the tissue retraction device in more than one direction. In some embodiments, the flexible tubular element of the tissue retraction device is formed along a distal segment of the flexible tubular element having a lumen for delivering an inflation medium to the tissue retraction device and a sealed distal end, a stiffening element is applied along a limited region of the circumference of the flexible tubular element of the tissue retraction device such that the peripheral region defines a highly flexible region of the tissue retraction device, the method further comprises selectively delivering inflation medium through the flexible tubular element to control bending of the tissue retraction device into the stiffening element.

[0016] These and other features and advantages of the present disclosure will become readily apparent from the following detailed description, and the scope of the claimed invention is set forth in the appended claims. Although the following disclosure is presented in terms of aspects or embodiments, it should be understood that each aspect can be claimed separately or in combination with aspects and features of that embodiment or any other embodiment.

[0017] Non-limiting embodiments of the present disclosure are described by way of example with reference to the accompanying drawings, which are schematic and are not intended to be drawn to scale. The accompanying drawings are provided for illustrative purposes only, and the dimensions, positions, order, and relative sizes reflected in the figures in the drawings may be changed. For example, devices may be enlarged so that details are discernible, but are intended to be reduced in relation to, for example, fitting within a working channel of a delivery catheter or endoscope. In these figures, identical, nearly identical, or equivalent elements are typically represented by the same reference numerals, and similar elements are typically indicated by different similar reference numerals that increment in increments of 100, and duplicate descriptions are omitted. For purposes of clarity and simplicity, not every element is labeled in every figure, and not every element of each embodiment is shown, unless illustration is necessary to enable the skilled artisan to understand the present disclosure.

[0018] The detailed description will be better understood in conjunction with the accompanying drawings, in which like reference numerals represent like elements and in which: [Brief description of the drawings]

[0019] [Figure 1] 1 illustrates a perspective view of one example of an embodiment of a tissue retraction system and device formed in accordance with various principles of the present disclosure; [Diagram 2] 2 shows a cross-sectional view of a portion of the tissue retraction device of FIG. 1 taken along line II-II. [Diagram 3]1 illustrates a perspective view of an example of one embodiment of a tissue retraction system and actuation mechanism according to various principles of the present disclosure. [Figure 4] 4 illustrates an example of operation of an embodiment of a tissue retraction system as shown in FIGS. 1-3. [Diagram 5] 4 illustrates an example of operation of an embodiment of a tissue retraction system as shown in FIGS. 1-3. [Figure 6] 1 illustrates a perspective view of another example of an embodiment of a tissue retraction system and device formed in accordance with various principles of the present disclosure. [Figure 7] 7 illustrates an example of operation of an embodiment of a tissue retraction system as shown in FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The following detailed description should be read with reference to the drawings showing exemplary embodiments. It should be understood that the disclosure is not limited to the specific embodiments described and may therefore be modified. All devices and systems and methods discussed herein are examples of devices, systems, and / or methods implemented according to one or more principles of the disclosure. Each example of an embodiment is provided as an illustration and is merely an example, not the only way to implement these principles. Thus, references to elements, or structures, or features in the drawings should be understood as references to example embodiments of the disclosure and should not be understood as limiting the disclosure to the specific elements, structures, or features shown. Other examples of ways to implement the disclosed principles will occur to those skilled in the art upon reading this disclosure. Indeed, it will be apparent to those skilled in the art that various modifications and changes can be made to the disclosure without departing from the scope or spirit of the subject matter. For example, features illustrated or described as part of one embodiment can be used in another embodiment to yield a further embodiment. It is therefore intended that the subject matter encompass such modifications and changes as fall within the scope of the appended claims and their equivalents.

[0021] It will be understood that in this application, the disclosure is described in various levels of detail. In certain instances, details that are not necessary for a person skilled in the art to understand the disclosure or that would make it difficult for the person skilled in the art to appreciate other details may be omitted. The terms used herein are for the purpose of describing certain embodiments only and are not intended to be limiting beyond the scope of the appended claims. Unless otherwise defined, technical terms used herein should be understood as commonly understood by those skilled in the art to which the disclosure belongs. All of the devices and / or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure.

[0022] As used herein, "proximal" refers to the direction or location closest to the user (e.g., medical professional, or clinician, or technician, or operator, or physician, etc., such terms are used interchangeably herein without limitation, including automated controller systems or otherwise) and / or closest to the delivery device, such as when using the device (e.g., when introducing the device into a patient or when implanting, placing, or delivering), and "distal" refers to the direction or location furthest from the user and / or closest to the delivery device, such as when using the device (e.g., when introducing the device into a patient or when implanting, placing, or delivering). "Longitudinal" means extending along the longer or larger dimension of an element. A "longitudinal axis" extends along the longitudinal extent of an element, but is not necessarily straight and does not necessarily maintain a fixed configuration when the element bends or flexes. "Center" means at least generally intersecting the center point and / or generally equidistant from the perimeter or boundary, and "central axis" means, with respect to an opening, a line that at least generally intersects the center point of the opening and extends longitudinally along the length of the opening, e.g., when the opening comprises a tubular element, post, channel, cavity, or bore. As used herein, a "channel" or "bore" is not limited to a circular cross section. As used herein, a "free end" of an element is a terminus beyond which such element does not extend.

[0023] In accordance with various principles of the present disclosure, tissue retraction systems and devices are constructed and designed to apply traction (e.g., tension, such as retraction) to a segment of tissue that has been separated (e.g., peeled) from surrounding tissue at a treatment site. It will be understood that terms such as segment, portion, area, section, etc. may be used interchangeably herein without any limitation, and generally, for convenience and distinction, without any limitation, a section may be referred to as a general region and a segment may be referred to as a specific portion. For convenience and without any limitation, a separated segment of tissue may be referred to herein as a tissue flap. It will be further understood that a treatment site may be alternatively referred to herein, without any limitation, as an anatomical site, a delivery site, a retention site, an implant / implantation site, a target site, etc.

[0024] More specifically, according to various principles of the present disclosure, the tissue retraction device is configured to bend in a desired (e.g., predetermined) direction to apply traction to a tissue flap with which the tissue retraction device is operably engaged. It will be understood that terms such as engage (and other grammatical forms) may be used interchangeably herein with terms such as bind, grasp, hold, fasten, clip, anchor, associate, attach, affix, secure, etc. (and other grammatical forms thereof) without any limitation intended. In some embodiments, the tissue retraction device has an elongated cylindrical body having a generally cylindrical surface. One or more tissue engaging features may be operably associated with the tissue retraction device, such as extending along a surface of the tissue retraction device. In some embodiments, the tissue engaging features are configured to be operably engaged by a tissue engaging member. In some embodiments, the tissue engaging features are extensions, such as loops, that can be engaged by a separately formed tissue engaging member, such as a tissue clip, that is configured to operably engage the tissue retraction device with tissue at the treatment site. In some embodiments, the tissue engaging features are formed with tissue engaging members, such as clips or jaws configured to grasp tissue, already coupled to the tissue engaging features.

[0025] The tissue retraction system may be used to actuate the tissue retraction device to bend in one or more different directions. In some embodiments, the tissue retraction system includes one or more elongate elements coupled to the tissue retraction device to actuate the movement of the tissue retraction device. In some embodiments, the tissue retraction device includes a region that is more flexible than the peripheral region such that actuation of the tissue retraction device causes the tissue retraction device to bend along the more flexible region in the direction of the less flexible peripheral region (generally toward a region substantially opposite the more flexible region). In some embodiments, only a limited peripheral segment of the tissue retraction device (a segment defined along a surface of the tissue retraction device and bounded by longitudinally extending boundaries that are circumferentially / circumferentially spaced apart from one another) has increased flexibility and / or extensibility relative to the peripheral region. Thus, only a portion of the periphery of the tissue retraction device bends to a greater extent than the peripheral region of the tissue retraction device, such that the tissue retraction device bends in such flexible region generally toward the opposite side of the tissue retraction device, which is less flexible. The flexible region may extend only along a limited longitudinal extent of the tissue retraction device or along the entire length of the tissue retraction device. The flexible region may be a limited pre-stretched region, and / or may be formed from a different material than the surrounding less flexible regions, and / or may have a thinner wall thickness than the surrounding regions to allow for relatively increased flexibility, and / or may otherwise be asymmetrically formed about its periphery to allow for bending of the tissue retraction device to be directed in a particular direction. It will be understood that the flexible segment may extend only along a limited longitudinal extent of the tissue retraction device or may be present along the entire length of the tissue retraction device.

[0026] In some embodiments, the retraction device comprises at least one flexible tubular element. The flexible segments of such tissue retraction devices may additionally or alternatively be more expandable than other regions of the tissue retraction device. Application of an inflation medium to the flexible tubular element of the tissue retraction device causes the flexible tubular element to expand and bend along the flexible and / or expandable regions, thereby applying a traction force to the tissue to which the retraction device is coupled.

[0027] In some embodiments, the tissue retraction system and tissue retraction device use pneumatic or hydraulic pressure to apply and maintain traction to the tissue flap. For example, the tissue retraction system may be configured to deliver an inflation medium to an inflation lumen in a flexible tubular element of the tissue retraction device to cause the tissue retraction device to expand along its flexible and / or expandable regions and thus bend toward a less expandable region (e.g., opposite the flexible and / or expandable regions) to apply traction to the tissue flap. In some embodiments, the flexible tubular element has a flexible expandable region surrounded by a less flexible region. Application of an inflation medium to the flexible tubular element of the tissue retraction device causes the flexible expandable region of the flexible tubular element to expand. However, the less flexible region does not expand (or may expand, but significantly less than the flexible expandable region expands). As a result, the flexible tubular element of the tissue retraction device bends toward the less flexible region as the size / length of the more flexible region increases (forming an outer portion of the bent tube with a larger radius of curvature).

[0028] In some embodiments, the tissue retraction system includes one or more elongate elements operably coupled to the tissue retraction device to actuate the tissue retraction device to bend the tissue retraction device in a desired direction. In some embodiments, the tissue retraction system and device use one or more tubular elements. The tubular elements may be configured to form a traction device at their distal end region (at the distal end and a limited longitudinal extent proximal thereto) that is coupled to the tissue to which traction is applied. For example, only a limited region of the distal end of each of the one or more tubular elements of the tissue retraction system is configured to form a tissue retraction device (e.g., a flexible tubular element of the tissue retraction device). Furthermore, only a limited region along the circumference of the distal end region of each of the one or more tubular elements of the tissue retraction system (forming the tissue retraction device) has low flexibility to allow for directionality of the resulting bending of the tissue retraction device upon actuation by the tissue retraction system (e.g., application and / or delivery of an actuating medium to the tissue retraction device). In other words, only a limited portion of the tubular element at its distal end (the distal end region forming the tissue retraction device) has a region that is more flexible and / or expandable than the remaining region of the tubular element, at a limited extent of the circumference of the tubular element. Thus, only a limited region along the circumference of the tissue retraction device bends or expands to a greater extent than the surrounding region, causing the tissue retraction device to bend generally toward the opposite side of the tissue retraction device, which is less flexible and / or expandable, at such flexible expandable region. The flexible expandable region may be a limited pre-stretched region, and / or may be formed from a different material than the surrounding less flexible and / or less expandable regions, and / or may have a thinner wall thickness than the surrounding region to allow for relatively increased flexibility and expandability, and / or may otherwise be formed asymmetrically about its circumference to allow for bending to be directed in a particular direction.

[0029] It will be appreciated that instead of a limited area along a limited extent of the circumference of the tissue retraction device having increased flexibility and / or expandability, the tubular element forming the tissue retraction device may be formed of a material having substantially uniform properties along its length and circumference, where the limited area along the limited extent of the circumference of the tissue retraction device has increased stiffness relative to the flexibility of the tubular element. Thus, the portion of the flexible tubular element forming the tissue retraction device expands to a greater extent in the area surrounding the area with increased stiffness, thus bending the tissue retraction device towards the area with increased stiffness. In some embodiments, the tissue retraction device is formed along a distal region of the flexible tubular element of the tissue retraction system, with the increased stiffness / rigid section formed along a limited area along the limited extent of the circumference of the tissue retraction device (i.e., only along one side or vertical segment of the surface of the tissue retraction device). For example, a stiffening element may be applied longitudinally along the tissue retraction device along the limited circumferential extent of the tissue retraction device. The stiffening elements may be materials that have reduced flexibility or extensibility relative to the tubular elements that form the tissue retraction device, or may otherwise simply add wall thickness to the tubular elements. The stiffening elements may be materials or coatings that are applied to limited areas of the tube wall to stiffen or otherwise reduce the extensibility of such areas.

[0030] Various embodiments of tissue retraction systems and devices will now be described with reference to examples shown in the accompanying drawings. Reference herein to "one embodiment," "an embodiment," "some embodiments," "other embodiments," etc. indicates that one or more particular features, structures, concepts, and / or characteristics according to the principles of the present disclosure may be included in connection with that embodiment. However, such reference does not necessarily mean that all embodiments include that particular feature, structure, concept, and / or characteristic, or that an embodiment includes all features, structures, concepts, and / or characteristics. Some embodiments may include one or more such features, structures, concepts, and / or characteristics in various combinations thereof. It should be understood that one or more of the features, structures, concepts, and / or characteristics described with reference to an embodiment may be combined with one or more of the features, structures, concepts, and / or characteristics of any of the other embodiments provided herein. That is, any of the features, structures, concepts, and / or characteristics described herein may be mixed and matched to create hybrid embodiments, and such hybrid embodiments are within the scope of the present disclosure. Furthermore, references in various places herein to "one embodiment," "an embodiment," "some embodiments," "other embodiments," etc., are not necessarily all referring to the same embodiment, nor to separate or alternative embodiments that are not necessarily mutually exclusive with other embodiments. Furthermore, it should be understood that various features, structures, concepts, and / or properties of the disclosed embodiments are independent and distinct from one another and may be used or exist individually or in various combinations with one another to create alternative embodiments that are considered part of this disclosure. Thus, since it would be too burdensome to describe all of the many possible combinations and subcombinations of features, structures, concepts, and / or properties, the disclosure is not limited to only the embodiments specifically described herein, and the example embodiments disclosed herein are not intended to limit the broad aspects of the disclosure. The following description is merely an illustrative example of an embodiment, and is not intended to limit the broad aspects of the disclosure.

[0031] It will be understood that in the drawings, common features are identified by common reference elements, and for brevity and convenience, and without intent of limitation, descriptions of common features will generally not be repeated. For clarity, not all components having the same reference number are labeled. Furthermore, groups of similar elements may be indicated by numbers and letters, and reference to one element or such elements as an element or group of such elements will generally be made by the number alone (without including the letter associated with each similar element). It will be understood that in the following description, for brevity, similar elements or components among the various illustrated embodiments will be indicated by the same reference numbers, generally incremented by 100, and duplicate descriptions will generally be omitted. Furthermore, a particular feature in one embodiment may be used across different embodiments and will not necessarily be individually labeled when appearing in different embodiments. Finally, it will be understood that the relative proportions of the elements of the illustrated systems and devices, and the environments in which the systems and devices are illustrated, are not necessarily drawn to scale.

[0032] Referring now to the drawings, Figure 1 shows an example of an embodiment of a tissue retraction system 100 having one or more elongate elements 110 forming a tissue retraction system 100 capable of applying a force to tissue, such as a traction force to lift the tissue. In the illustrated example of an embodiment of a tissue retraction system 100, the tissue retraction device 120 is defined by a longitudinal extent of the elongate element 110 that extends proximally from a distal end 111 of the elongate element 110 a desired distance, defining a length L of the tissue retraction device 120 along a longitudinal axis LA. For example, when used in the gastrointestinal system, this distance should be sufficient to reach the stomach wall or intestinal wall, depending on the particular location of the tissue retraction device 120. However, other configurations are within the scope and spirit of the present disclosure.

[0033] In accordance with various principles of the present disclosure, the tissue retraction device 120 is an elongated cylindrical body having its segments 124 configured to be more flexible and / or expandable than the surrounding regions of the tissue retraction device 120. Such segments 124 may be along a limited circumferential / peripheral extent of the circumference / periphery of the tissue retraction device 120 to allow it to bend or flex in a controllable and predictable direction. It will be understood that terms such as bend, flex, navigate, steer, move, etc. (including other grammatical forms thereof) are used interchangeably herein without any intent of limitation. It will further be understood that the cylindrical body of the tissue retraction device 120 may have a circular cross-section and thus a perimeter, or may have a cross-section of a different shape, and thus may more generally refer to its perimeter. References herein to a perimeter or perimeter may be for convenience and should not be understood as limiting the cross-section of the tissue retraction device 120 to a particular shape. Typically, the flexible and / or expandable segment 124 is defined by the tissue retraction device 120 and thus its longitudinal extent is limited to the length L of the tissue retraction device 120. However, it will be understood that the flexible and / or expandable segment 124 may extend only along a limited longitudinal extent of the tissue retraction device 120 (and not along the entire length L).

[0034] More specifically, in accordance with various principles of the present disclosure, the flexible and / or expandable segments 124 are longitudinal circumferential segments 124 of the tissue retraction device 120 that are formed to have increased flexibility and / or expandability relative to the peripheral regions of the tissue retraction device 120. For example, the flexible and / or expandable segments 124 may be limited pre-stretched regions (e.g., regions that can be stretched to a greater extent than the peripheral regions) and / or may be formed from a different material than the peripheral regions and / or may have a thinner wall thickness than the peripheral regions to allow increased flexibility and expandability along the periphery of the tissue retraction device 120 relative to the peripheral regions. In some embodiments, such flexible and / or expandable segments 124 are asymmetrically formed on the periphery of the tissue retraction device 120 to allow directional bending of the tissue retraction device 120 (i.e., directing bending of the tissue retraction device 120 in a particular direction generally opposite, e.g., diametrically opposite, the flexible and / or expandable segments 124). At least in one example embodiment shown in FIG. 1, the flexible and / or expandable segments 124 are longitudinal circumferential segments 124 that extend longitudinally along at least a portion of the length L of the tissue retraction device 120, with longitudinal boundaries spaced circumferentially apart from one another. In other words, the longitudinal circumferential segments 124 extend along only a portion of the sides of the longitudinal extent of the tissue retraction device 120. In some embodiments, the longitudinal extent L of the longitudinal circumferential segments 124 is along the entire length L of the tissue retraction device 120. However, it will be understood that the longitudinal circumferential segments 124 may be shorter than the entire length L of the tissue retraction device 120, and are strategically positioned to effect bending of the tissue retraction device 120 in a desired area along the length L of the tissue retraction device 120. For convenience, and without any intent of limitation, the flexible / expandable segments / longitudinal circumferential segments 124 may be referred to herein as flexible and / or expandable bending regions 124 of the tissue retraction device 120.

[0035] Additionally or alternatively, a region of the tissue retraction device 120 surrounding the flexible and / or expandable bending region 124 is formed to have reduced flexibility and / or extensibility relative to the flexible and / or expandable bending region 124. Because the flexible and / or expandable bending region 124 does not extend along the entire periphery or circumference of the tissue retraction device 120, actuation (e.g., expansion) thereof causes the tissue retraction device 120 to bend toward a less flexible and / or less extensible region in the area of ​​the flexible and / or expandable bending region 124, as described in further detail below.

[0036] In accordance with various principles of the present disclosure, the one or more elongate elements 110 of the tissue retraction system 100 are one or more flexible tubular elements 110 that define a tissue retraction device 120 along a distal length L of the flexible tubular element 110. The distal end 111 of the flexible tubular element 110 is sealed such that an actuating medium may be delivered by the tissue retraction system 100 to the tissue retraction device 120 to actuate the tissue retraction device 120. In some embodiments, the actuating medium is an inflation medium. The flexible / expandable bending region 124 is configured to expand to a greater extent than the surrounding region of the tissue retraction device 120 upon delivery of an inflation medium to the tissue retraction device 120. The expansion of the flexible / expandable bending region 124 increases the length of such region / segment of the tissue retraction device 120 relative to the length of the surrounding segments / regions, thereby causing bending of the tissue retraction device 120 (generally opposite, e.g., diametrically opposite, the flexible and / or expandable bending region 124) toward the less flexible / expandable region of the tissue retraction device 120. The flexible / expandable bending region 124 defines the outer bending of the tissue retraction device 120, or in other words, is disposed along a bent surface of the tissue retraction device 120 that has a larger radius of curvature (resulting from actuation of the tissue retraction system 100 to bend the tissue retraction device 120).

[0037] In some embodiments, tissue engaging features 122a are provided along the distal end 121 of the tissue retraction device 120. For example, when multiple flexible elements 110 form the tissue retraction device 120, tissue engaging features 122a may be provided along the distal end 111 of each of the flexible elements 110. The tissue engaging features 122a may be protrusions that facilitate attachment of the tissue retraction device 120 to tissue, such as by a tissue engaging member. In an example embodiment shown in FIG. 1, the tissue engaging features 122a are loops that are engaged by a separately formed tissue engaging member 130. The example embodiment of the tissue engaging member 130 shown in FIG. 1 has one or more jaws 132 configured to grasp tissue at a treatment site TS, such as a target tissue TT to which traction is applied by the tissue retraction device 120 and the tissue retraction system 100. However, it will be understood that other forms of tissue engaging members, such as those known to those skilled in the art, are within the scope and spirit of the present disclosure. It will further be appreciated that the tissue engaging member 130 may be integrally formed with the tissue engaging feature 122a instead of being a separately formed element coupled to the tissue engaging feature 122a. The tissue engaging member 130 may be coupled to or provided with the tissue engaging feature 122a during delivery of the tissue retraction device 120 to the treatment site TS. The tissue engaging member 130 may be actuated to grasp tissue at the treatment site TS in order to deploy / couple the tissue retraction device 120 to the treatment site TS. Any desired actuator or end effector (details of which are not critical to the present disclosure) known to those skilled in the art may be used to actuate the tissue engaging member 130, for example.

[0038] In some embodiments, one or more additional tissue engaging features are provided along the proximal end 123 of the tissue retraction device 120, such as the proximal tissue engaging feature 122b as shown in FIG. 1. Such additional tissue engaging features may be similar in configuration to the tissue engaging feature 122a described above (such description is referred to for brevity) or may be of other configurations that facilitate engagement of the tissue retraction device 120 with tissue. The proximal tissue engaging feature 122b shown in FIG. 1 is similar to the distal tissue engaging feature 122a described above. However, typically, the tissue engaging member 130 does not engage the proximal tissue engaging feature 122b during delivery of the tissue retraction device 120 to the treatment site TS. Instead, the tissue engaging member 130 is typically delivered separately and actuated to grasp the proximal tissue engaging feature 122b and then grasp tissue away from the target tissue TT to apply traction to the target tissue TT in a manner understood by one of ordinary skill in the art. Further details of examples of uses of tissue retraction system 100 and tissue retraction device 120 as shown in FIG. 1 are provided below.

[0039] As shown in FIG. 2, which shows a cross-sectional view along line II-II of FIG. 1, the illustrated example of one embodiment of the tissue retraction device 120 of FIG. 1 may be formed with one or more flexible tubular elements 126. Each of the flexible tubular elements 126 may be formed along each of the flexible tubular elements 110 forming the tissue retraction system 100. More specifically, the flexible tubular elements 126 may be formed along a distal segment of the flexible tubular elements 110 of the tissue retraction system 100 extending proximally from their respective distal ends 111. In the illustrated example of one embodiment, the tissue retraction device 120 is formed with three flexible tubular elements 126 arranged in a generally triangular configuration such that they are joined (or if not joined, are at least adjacently disposed) along a common joint region 115. The common joint region 115 generally inhibits the extensibility of the walls of the flexible tubular elements 126 in such region. Thus, the area around the common bond region 115 forms a flexible and / or expandable bending region 124 of the flexible tubular element 126 of the tissue retraction device 120. In some embodiments, the flexible tubular element 126 is formed of a resilient material (e.g., silicone or other suitable biocompatible material) that allows for its radial expansion at least along the flexible and / or expandable bending region 124. In some embodiments, the flexible and / or expandable bending region 124 is pre-stretched along a defined length to further facilitate its expansion and allow the tissue retraction device 120 to reach the wall of the tissue where the procedure is to be performed.

[0040] According to various principles of the present disclosure, one manner of actuating the tissue retraction device 120 to bend (e.g., as shown in FIG. 1 ) is by expansion of a flexible and / or expandable bending region 124 of the tissue retraction device 120 caused by selective expansion of a distal portion of the flexible tubular element 110 forming the tissue retraction device 120. For example, as shown in FIG. 3 , one or more actuation mechanisms 140 are operably coupled to the proximal end 113 of each of the flexible tubular elements 110 of the tissue retraction system 100, such as in FIGS. 1 and 2 . In some embodiments, the actuation mechanism 140 is a syringe that applies an actuation medium, such as an expansion medium (e.g., saline or other biocompatible fluid, such as carbon dioxide gas), to the tissue retraction device 120 via the flexible tubular element 110. The actuation mechanism 140 is shown beside a separately formed control handle 150. However, other arrangements are within the scope and spirit of the present disclosure. The control handle 150 may be used to control an endoscope 160 that may deliver instruments, devices, tools, etc. (such terms are used interchangeably herein without limitation) to the treatment site TS to perform an intended procedure at the treatment site TS. For example, as shown in FIG. 1, the endoscope 160 may deliver a cutting tool 170 (e.g., a knife, scalpel, electrocautery device, etc., the present disclosure is not limited to any particular such tool) to perform an incision or resection of tissue, and the tissue retraction device 120 applies traction to a flap of tissue created thereby. In an example embodiment shown in FIGS. 1 and 3, the tissue retraction system 100 is configured to extend outside of the endoscope 160 instead of through the working channel 162 of the endoscope 160. Such a configuration allows the working channel 162 of the endoscope 160 to be cleared for delivery of the cutting tool 170 while the tissue retraction system 100 is in place and operational. The tissue retraction system 100 may be coupled to the endoscope 160. The tissue retraction system 100 may be freely movable relative to the endoscope 160, whether or not it is coupled to the endoscope 160.

[0041] 3, selective application of an actuating medium, e.g., controlled by one of the actuating mechanisms 140, causes expansion of only the flexible and / or expandable bending regions 124 in fluid communication with the flexible tubular elements 110 operatively associated with the actuated actuating mechanism 140. For example, application of an actuating medium to selected flexible tubular elements 126 of the tissue retraction device 120 increases pressure within such flexible tubular elements, causing expansion of the flexible and / or expandable bending regions 124. Regions of the walls of the flexible tubular elements 126 of the tissue retraction device 120 along the common junction region 115 are less expandable (e.g., may be stiffer or at least do not have space available for expansion). Thus, expansion of the flexible and / or expandable bending region 124 of the actuated flexible tubular element 126 of the tissue retraction device 120 causes the actuated flexible tubular element 126 to bend toward the common junction region 115 (e.g., by effectively increasing the length of the flexible and / or expandable bending region 124 without equally increasing the length of the common junction region 115 of the actuated flexible tubular element). The medical professional operating the tissue retraction system 100 can determine which of the flexible tubular elements 126 of the tissue retraction system 100 and the tissue retraction device 120 to actuate (e.g., pressurize) in order to direct the bending of the tissue retraction device 120 in a desired direction. For example, a medical professional can actuate a selected actuation mechanism 140 to expand one or more of the flexible tubular elements 126 forming the tissue retraction device 120, causing such actuated flexible tubular elements 126 to bend, thereby bending the tissue retraction device 120, and lifting the target tissue TT in different directions or along different angles (e.g., along different force vectors), for example as shown in Figures 4 and 5.

[0042] An example of the operation of the tissue retraction system 100 and tissue retraction device 120 as shown in Figures 1, 2, 3, 4, and 5 is as follows: A tissue engaging member 130 is introduced into the endoscope 160, and the tissue engaging member 130 is attached to the tissue engaging feature 122a at the distal end 121 of the tissue retraction device 120. Optionally, but not required, the tissue engaging member 130 is introduced into the endoscope 160 while the endoscope 160 is external to the patient. The endoscope 160 is introduced into the patient, and the tissue engaging member 130 (operably engaged with the tissue engaging feature 122a of the tissue retraction device 120) is attached to the target tissue TT. A second tissue engaging member 130 is introduced through the working channel 162 of the endoscope 160. The medical professional selects one of the additional tissue engaging features, such as the illustrated proximal tissue engaging feature 122b, and attaches the second tissue engaging member 130 to it and to tissue distal to the target tissue TT (e.g., on the opposite side of the lumen wall in which the target tissue TT is located). The medical professional controls the position of the target tissue TT using the actuation mechanism 140 in the manner described above.

[0043] It will be understood that various modifications to the tissue retraction system 100 and / or tissue retraction device 120 described above are within the scope and spirit of the present disclosure. For example, only one resilient flexible tubular element may be used in the tissue retraction system to form the tissue retraction device. In such an embodiment, as shown in Figs. 7 and 8, a limited region of the tissue retraction device 220 formed by a single flexible tubular element 210 of the illustrated example of one embodiment of the tissue retraction system 200 may be less flexible to provide a similar bending action described above with reference to the tissue retraction system 100 and tissue retraction device 120 shown in Figs. 1-5. For example, a longitudinal circumferential segment 224 along only a portion of the periphery or circumference or face of the flexible tubular element 210 is made less flexible / stiffer and / or less extensible than other peripheral regions. As with the example of one embodiment described above, the longitudinal circumferential segment may extend only along the entire length L or to a limited extent along the length L of the tissue retraction device 220. The limited low flexibility and / or low extensibility bending segment 224 may have a similar effect as the flexible and / or extensible bending segment 124 of the tissue retraction device 120 of the above example of an embodiment of the tissue retraction system 100, allowing bending of the tissue retraction device 220 in only one direction toward the low flexibility and / or low extensibility bending segment 224. In some embodiments, the low flexibility and / or low extensibility bending segment 224 is formed by application of a stiffening element such as an additional material (such as a patch or coating) along a limited extent of the circumference of the tissue retraction device 220 and optionally along a limited length of the tissue retraction device 220. Thus, this solution may be simpler than the previous embodiment, but may lack some maneuverability options available in the previous embodiment. It will be understood that the example embodiment shown in Figures 6 and 7 has various other features in common with the example embodiment shown in Figures 1-5. Thus, the common features are identified by common reference elements incremented by 100, and for the sake of brevity, the description of the common features will not be repeated. For purposes of clarity, not all components are labeled with the same reference number.

[0044] The tissue retraction system 200 as shown in Figures 6 and 7 may be operated in a manner similar to that described above with respect to the tissue retraction system 100 of Figures 1-5, and therefore, for brevity and without intent of limitation, reference is made to the above description of an example of operation. It will be understood that in various embodiments, some steps of assembly of the tissue retraction device may be performed outside the patient's body and other steps involved in assembly of the tissue retraction device may be performed within the patient. The steps described herein are not necessarily performed in any particular order and / or timing.

[0045] It will be understood that further modifications to the above tissue retraction systems and devices are within the scope and spirit of the present disclosure. For example, a tissue retraction device formed according to various principles of the present disclosure need not necessarily occupy the same area as the elongate elements forming the tissue retraction system formed according to various principles of the present disclosure. For example, the tissue retraction device may be formed from flexible tubular elements formed separately from the elongate elements forming the tissue retraction system. Thus, the diameter of the elongate elements forming the tissue retraction system may be smaller than the diameter of the components of the tissue retraction device to facilitate transluminal / transcatheter navigation of the tissue retraction system. Such a configuration may facilitate the formation of tissue retraction devices having segments of increased flexibility and / or stiffness.

[0046] Various further advantages of the various aspects, features, components, and structures of the tissue retraction system and / or tissue retraction device as described and discussed above may be appreciated by those skilled in the art. All of the devices and methods discussed herein are examples of devices and / or methods implemented according to one or more principles of the present disclosure. These examples are not the only ways of implementing these principles, but are merely examples and are not intended to limit the broader aspects of the present disclosure. Thus, references to elements or structures or features in the drawings should be understood as references to examples of embodiments of the present disclosure and should not be understood as limiting the present disclosure to the specific elements, structures, or features shown. Other examples of ways of implementing the disclosed principles will occur to those skilled in the art upon reading the present disclosure. It will be understood that features described with respect to one embodiment may typically be applied to another embodiment, whether or not explicitly shown. The various features described below may be used alone or in any combination thereof. Therefore, the present invention is not limited to only the embodiments specifically described herein.

[0047] The foregoing discussion has broad applicability and is presented for purposes of illustration and explanation, and is not intended to limit the disclosure to one or more forms disclosed herein. It will be understood that various additions, modifications, and substitutions can be made to the embodiments disclosed herein without departing from the concept, spirit, and scope of the disclosure. In particular, it will be apparent to those skilled in the art that the principles of the disclosure can be embodied in other forms, structures, arrangements, ratios, and using other elements, materials, and components without departing from the concept, spirit, or scope or characteristics thereof. For example, various features of the disclosure have been grouped together in one or more aspects, embodiments, or configurations for the purpose of streamlining the disclosure. However, it should be understood that various features of a particular aspect, embodiment, or configuration of the disclosure can be combined in alternative aspects, embodiments, or configurations. Although the disclosure is presented in terms of embodiments, it should be understood that the various separate features of the subject matter need not all be present to achieve at least some of the desired properties and / or advantages of the subject matter or such individual features. Those skilled in the art will appreciate that the present disclosure can be used with many modifications specifically adapted to particular environments and operating requirements, or with structure, arrangement, proportions, materials, components, and other modifications used in the practice of the present disclosure, without departing from the principles, spirit, or scope of the present disclosure. For example, elements shown as integrally formed can be composed of multiple pieces, or elements shown as multiple pieces can be formed integrally, operations of elements can be reversed or otherwise changed, and elements can be changed in size or dimensions. Similarly, although operations, actions, or steps are described in a particular order, this should not be understood as requiring such a particular order or that all operations, actions, or steps should be performed to achieve desired results. Furthermore, other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results.The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the claimed subject matter being indicated by the appended claims and not limited to the foregoing description or to the specific embodiments or configurations described or illustrated herein. In view of the above, the individual features of any embodiment can be used and claimed separately or in combination with the features of that embodiment or any other embodiment, and the scope of the subject matter being indicated by the appended claims and not limited to the foregoing description.

[0048] In the above description and in the claims that follow, it will be understood that: The terms "at least one," "one or more," and "and / or," as used herein, are open-ended expressions that function both conjunctively and disjunctively. The terms "a," "an," "the," "first," "second," etc. do not exclude a plurality. For example, the term "a" or "an" entity, as used herein, refers to one or more of that entity. Thus, the terms "a" (or "an"), "one or more," and "at least one" can be used interchangeably herein. As used in this specification and the appended claims, the term "or" is generally used in its sense to include "and / or," unless the content clearly dictates otherwise. As used herein, the conjunction "and" includes each of the structures, components, features, etc. so connected, unless the context clearly dictates otherwise, and the conjunction "or" includes one or the other of the structures, components, features, etc. so connected, alone as well as in any combination and number, unless the context clearly dictates otherwise. All directional references (e.g., proximal, distal, upper, lower, upward, downward, left, right, lateral, longitudinal, front, rear, top, bottom, above, below, vertical, horizontal, radial, axial, clockwise, counterclockwise, etc.) are used for identification purposes only to aid the reader in understanding this disclosure and / or serve to distinguish regions of associated elements from one another and do not limit the associated elements, particularly with respect to position, orientation, or use of this disclosure. Connection references (e.g., attached, coupled, connected, engaged, and joined) should be interpreted broadly and may include intermediate members between groups of elements, and relative movement between the elements, unless otherwise indicated. Thus, connection references do not necessarily imply that two elements are directly connected and in a fixed relationship to each other.Distinguishing references (e.g., primary, secondary, first, second, tertiary, fourth, etc.) are not intended to imply importance or priority, but are used to distinguish one feature from another.

[0049] The following claims are hereby incorporated by reference into this Detailed Description with each claim standing as an independent embodiment of this disclosure. In the claims, the terms "comprises", "comprising", "includes" and "including" do not exclude the presence of other elements, components, features, groups, regions, integers, steps, operations, etc. Furthermore, although individual features may be included in different claims, these may in some cases be advantageously combined, and the inclusion in different claims does not imply that a combination of features is not feasible and / or advantageous. Furthermore, reference to the singular does not exclude a plurality. Reference signs in the claims are provided merely as a clarifying example and shall not be construed as limiting the scope of the claims in any way.

Claims

1. A tissue retraction device; one or more elongate elements operably coupled to the tissue retraction device to actuate bending of the tissue retraction device; Equipped with a longitudinal circumferential region of the tissue retraction device is more flexible than a peripheral region of the tissue retraction device, such that actuation of the tissue retraction device causes bending along a more flexible region toward a less flexible region; Tissue traction system.

2. The tissue retraction system of claim 1 , wherein the tissue retraction device is formed by a distal extent of the one or more elongate elements extending a length proximal to a distal end of the one or more elongate elements.

3. The tissue retraction system of claim 1 or 2, wherein at least one of the elongate elements is a flexible tubular element.

4. The tissue retraction system of claim 3 , wherein at least one of the flexible tubular elements has a sealed distal end.

5. The tissue traction system of any one of claims 1 to 4, further comprising an actuation mechanism operably coupled to the one or more elongate elements for causing bending of the tissue traction device.

6. a distal extent of the at least one flexible tubular element forming a flexible tubular element of the tissue retraction device; the longitudinal circumferential region of the tissue retraction device is formed along a distal region of the at least one flexible tubular element and is more expandable than a peripheral region of the tissue retraction device; the actuation mechanism delivers an inflation medium through the at least one flexible tubular element to the tissue retraction device to expand the longitudinal circumferential region of the tissue retraction device relative to a peripheral region of the tissue retraction device to bend the tissue retraction device. The tissue retraction system of claim 5 .

7. The tissue retraction system of claim 1 , wherein stiffening elements are applied along limited regions along the periphery of the tissue retraction device, such that the peripheral regions are relatively more flexible.

8. the one or more elongate elements include a flexible tubular element having a sealed distal end; the tissue retraction device is formed by a distal extent of the flexible tubular element extending a length proximal to the sealed distal end of the flexible tubular element; the tissue retraction device is directionally expandable upon application of an expansion medium to expand highly flexible regions of the tissue retraction device and bend the tissue retraction device toward the stiffening element; The tissue traction system according to any one of claims 1 to 7.

9. an elongate cylindrical body extending along a longitudinal axis and having a distal end, a proximal end, and a flexible segment extending along only a portion of a circumference of the cylindrical body between the distal end and the proximal end; Equipped with the flexible segment being more flexible than the surrounding portion of the cylindrical body to facilitate bending of the cylindrical body along the flexible segment; Tissue traction devices.

10. the cylindrical body being tubular and expandable; the flexible segment has a higher extensibility than the surrounding portion of the cylindrical body, such that expansion of the tubular cylindrical body causes the flexible segment to expand and bend toward the opposite, less extensible side of the cylindrical body; The tissue retraction device of claim 9.

11. The tissue retraction device of claim 9 or 10, wherein the flexible segment extends only along a limited extent along the longitudinal axis of the cylindrical body.

12. 12. The tissue retraction device of claim 9, wherein the cylindrical body is formed of a flexible material, and a stiffening element is applied to a limited extent of the periphery of the flexible cylindrical body, and the flexible segment is defined opposite the stiffening element.

13. The tissue retraction device according to any one of claims 9 to 11, wherein the cylindrical body is a distal segment of a flexible tubular element of a tissue retraction system.

14. 1. A method of actuating a tissue retraction device having a tissue engaging feature at a distal end, comprising: actuating the tissue retraction device to bend along a flexible region adjacent the distal end of the tissue retraction device, the flexible region being more flexible than a surrounding region, toward a region of the tissue retraction device opposite the flexible region, thereby bending the distal end of the tissue retraction device relative to the proximal end of the tissue retraction device. A method comprising:

15. 15. The method of claim 14, wherein the tissue retraction device is tubular, the method further comprising actuating the tissue retraction device by delivering an inflation medium to a lumen defined within the tissue retraction device to expand a flexible segment of the tissue retraction device relative to a surrounding area and bend the tissue retraction device in a direction generally opposite to the flexible segment.

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