Devices and Methods for Tissue Retraction

Abstract

The present invention relates to the field of tissue dissection. Specifically, the present invention relates to a medical device for lifting and retracting tissue during a dissection procedure to improve visualization of the target tissue and to relieve obstacles caused by dissection tools. In particular, the present invention relates to a device for converting from a constrained configuration to an unconstrained arcuate configuration during a dissection procedure to secure and retract an excised portion of the target tissue.

Description

[0001] This application is a divisional application of the application with the application number 201880021271.1, the filing date of March 28, 2018, and the title "Devices and Methods for Tissue Retraction".

[0002] Priority

[0003] This application claims the benefit of priority of U.S. Provisional Patent Application Serial No. 62 / 478,169, filed on March 29, 2017, the entire content of which is incorporated herein by reference and used for all purposes in accordance with 35 U.S.C.§119. Technical Field

[0004] The present invention relates to the field of tissue dissection. Specifically, the present invention relates to medical devices for lifting and retracting tissue during dissection surgery to improve visualization of the target tissue and reduce obstacles caused by dissection tools. In particular, the present invention relates to a device that transforms from a constrained form to an unconstrained arcuate form during dissection surgery to fix and retract the resected portion of the target tissue. Background Art

[0005] Due to poor visualization of the target tissue during dissection surgery, resection of lesions in narrow body passages, such as within the digestive tract, can be inefficient and time-consuming. This problem may be exacerbated during surgery because the partially resected target tissue obstructs the working area, further reducing visibility and hindering dissection tools. Therefore, various advantages can be achieved through the medical devices and methods for tissue retraction and resection in the present invention. Summary of the Invention

[0006] The present invention, in its various aspects, relates to tissue retraction devices and methods for fixing and retracting target tissue during dissection surgery to improve tissue visualization and manipulation.

[0007] Embodiments of the present invention may include a tissue retractor system having a delivery catheter that may include an inner tubular element having a lumen therethrough; an outer sheath disposed about the inner tubular element, the outer sheath and the inner tubular element being slidably disposed relative to each other; and an elongate flexible element configured to transition between a first configuration when constrained and a second arcuate configuration when unconstrained. The elongate flexible element may be disposed within the lumen of the inner tubular element, the elongate flexible element and the inner tubular element being slidably disposed relative to each other and the outer sheath, and the elongate flexible element may include a distal end having an end width and configured to engage a first target tissue portion. The elongate flexible member may include a proximal end having an end width and configured to engage a second target tissue portion. The elongate flexible member may include a body portion having a body width that connects the distal end to the proximal end, wherein the body width may be wider than the end widths of the distal end and the proximal end, and wherein the lumen of the inner tubular element may have a cross-section that accommodates the body width and the end widths of the distal end and the proximal end.

[0008] The tissue retractor system may include a first portion of a cross-section of a lumen of an inner tubular element that may generally match the body width of the body portion of the lumen of the inner tubular element. A system with an elongate flexible element may include a second portion of a cross-section of a lumen of an inner tubular element that may generally match the end widths of the distal and proximal ends of the body portion of the elongate flexible element. A system may include an outer sheath having a slot, whereby one or both of the outer sheath and the inner tubular element are rotated relative to each other to align the slot with the second portion of the cross-section of the inner tubular element, thereby allowing at least one anchor at the end of the elongate flexible element to be deployed radially outward from the outer sheath. A system may include an outer sheath that may have a slot, whereby one or both of the outer sheath and the inner tubular element are slid relative to each other to align the slot with the second portion of the cross-section of the inner tubular element, thereby allowing at least one anchor at the end of the elongate flexible element to be deployed radially outward from the outer sheath. A system may include a sheath having a slot that is wider at the distal end of the sheath than at its proximal end. A system may include an inner tubular element having a second portion cross-section that may open into the periphery of the inner tubular element along the longitudinal axis of the inner tubular element. A system may include an outer sheath having a slot at the distal end, the width of the slot generally matching the end widths of the distal and proximal ends of the elongate flexible element along its length. A system may include an outer sheath that may have a slot, the slot having a width extending along the longitudinal axis of the outer sheath, and wherein the width of the slot generally matches the end widths of the distal and proximal ends of the elongate flexible element. A system may include a generally T-shaped cross-section of an inner tubular element, and wherein the first portion of the cross-section is configured to slidably receive the body portion of the elongate flexible element, and the second portion of the cross-section is configured to slidably receive the distal and proximal ends of the elongate flexible element. A system may include a generally C-shaped cross-section of an inner tubular element, wherein the first portion of the cross-section is configured to slidably receive the body portion of the elongate flexible element, and the second portion of the cross-section is configured to slidably receive the distal and proximal ends of the elongate flexible element. A system may include a pusher member slidably disposed within a lumen proximal to the elongate flexible element, whereby distal movement of the pusher member causes the elongate flexible element to extend distally and translate. A system may include the distal and proximal ends of the elongate flexible element, wherein each end may include one or more tissue anchors selected from the group consisting of barbs, forks, hooks, fingers, barbs, loops, and clips.

[0009] An organization retractor system may include a plurality of tissue fasteners. A system may include an elongate flexible element that may have a proximal end and a distal end, each end configured to be engaged by a tissue fastener. A system may include at least one guide member attached to the elongate flexible element, wherein the at least one guide member defines a lumen extending therethrough. A system may include a control line configured to be slidably received within the lumen of the at least one guide member. An elongate flexible element may be convertible between a first configuration when the control line is disposed within the lumen of the at least one guide member and a second configuration when the control line is removed from the lumen of the at least one guide member. A system may include at least one delivery catheter configured to deliver the elongate flexible element and at least one tissue fastener.

[0010] A system may include a proximal end of an elongate flexible member having a proximal loop configured to be engaged by one of a plurality of tissue fasteners; and a distal end including a distal loop configured to be engaged by a different one of the plurality of tissue fasteners. A system may include each of the proximal and distal loops of the elongate flexible element, which may be larger than the tissue grasping portion of each of the plurality of tissue fasteners. A system may include a proximal end of an elongate flexible member having a proximal arm configured to be engaged by one of a plurality of tissue fasteners; and a distal end that may have a distal arm configured to be engaged by another one of the plurality of tissue fasteners. A system may include an elongate flexible element that may include a pair of generally parallel elements in a first configuration, each element having a flexible arcuate portion that extends generally away from each other in a longitudinal plane in a second configuration. A system may include at least one arm that extends from a body between the proximal and distal ends of the elongate flexible element. A system may include at least one arm having an end configured to be engaged by a tissue fastener.

[0011] An elongate flexible element may include a proximal end and a distal end each having a loop configured to be engaged by a tissue fastener. At least one guide member may be attached to the elongate flexible element, wherein the at least one guide member defines a lumen extending therethrough. A control line may be configured to be slidably received within the lumen of the at least one guide member. The elongate flexible element may be convertible between a first configuration when the control line is disposed within the lumen of the at least one guide member and a second configuration when the control line is removed from the lumen of the at least one guide member. An elongate flexible element may include a pair of generally parallel elements in a first configuration, each element having a flexible arcuate portion that extends generally away from each other in a longitudinal plane in a second configuration. An elongate flexible element may include at least one arm that extends from a body between the proximal and distal ends of the elongate flexible element. An elongate flexible element may include a guide member having a visual marker at an end of the guide member. Description of the Drawings

[0012] Non-limiting examples of the present invention are described by way of example with reference to the accompanying drawings, which are schematic and not to scale. In the drawings, each identical or nearly identical component shown is generally represented by a single number. For clarity, not every component is labeled in every figure, and not every component of every embodiment of the present invention is shown, where the description is not necessary for those skilled in the art to understand the present invention. In the drawings:

[0013] Figure 1 is an illustration of a system deployed by an endoscope according to an embodiment of the present invention.

[0014] Figure 2A is an illustration of an elongate flexible element in a constrained configuration according to an embodiment of the present invention.

[0015] Figure 2B is Figure 2A an illustration of the elongate flexible element in an unconstrained configuration in.

[0016] Figure 3A is a side cross-sectional view of a system according to an embodiment of the present invention.

[0017] Figure 3B is Figure 3A an illustration of the system in a constrained configuration in.

[0018] Figure 3C is Figure 3A and 3B an illustration of the outer sheath of the system in a deployed configuration in.

[0019] Figure 3D is Figures 3A to 3C an illustration of the deployment of the elongate flexible element of the system in.

[0020] Figure 3E is Figures 3A to 3D an illustration of the system removing a target tissue to be excised by an anatomical element in.

[0021] Figure 4A is an illustration of a system according to an embodiment of the present invention having a slot at the distal end of the outer sheath and the inner tubular element having a lumen cross-section, the lumen cross-section having a first part and a second part that together form a T-shape.

[0022] Figure 4B is an illustration of a system according to an embodiment of the present invention having a slot at the distal end of the outer sheath and the inner tubular element having a lumen cross-section, the lumen cross-section having a first part formed in a C-shape and a second part that is tangentially open to the periphery of the inner tubular element.

[0023] Figure 5Illustration of a system according to an embodiment of the present invention, having a slot along the outer sheath, where the width of the slot is wider at its distal end than at its proximal end.

[0024] Figure 6A Illustration of a bistable spring as an elongate flexible element in a generally planar configuration according to an embodiment of the present invention.

[0025] Figure 6B Is Figure 6A Illustration of the elongate flexible element in a generally arcuate configuration in

[0026] Figure 6C Is Figure 6A And 6B Illustration of the elongate flexible element within a delivery catheter in

[0027] Figure 7A Side cross-sectional view of an inner tubular element having a varying cross-sectional lumen according to an embodiment of the present invention.

[0028] Figure 7B Is Figure 7A Illustration of the cross-section at section 7B in

[0029] Figure 7C Is Figure 7A Illustration of the cross-section at section 7C in

[0030] Figure 7D Is Figure 7A Illustration of the cross-section at section 7D in

[0031] Figure 8A Illustration of an elongate flexible element having barbs according to an embodiment of the present invention.

[0032] Figure 8B Illustration of an elongate flexible element having a hook according to an embodiment of the present invention.

[0033] Figure 8C Illustration of an elongate flexible element having a hook according to an embodiment of the present invention.

[0034] Figure 8D Illustration of an elongate flexible element having a hook according to an embodiment of the present invention.

[0035] Figure 9A Illustration of a system being deployed according to an embodiment of the present invention.

[0036] Figure 9B Is Figure 9A Illustration of an embodiment of the system in , where the loop at the end of the elongate flexible element is engaged by a tissue fastener.

[0037] Figure 9C IsFigure 9A and 9B An illustration of the system in which an elongate flexible element and tissue fasteners are being deployed.

[0038] Figure 9D is Figures 9A to 9C An illustration of the system in which the elongate flexible element is being translated to a position above the target tissue.

[0039] Figure 9E is Figures 9A to 9D An illustration of the system in which a second tissue fastener is engaging a loop of the elongate flexible element and also engaging the target tissue.

[0040] Figure 9F is Figures 9A to 9E An illustration of the system in which a control line is being removed.

[0041] Figure 9G is Figures 9A to 9F An illustration of the system in which an anatomical element is removing the target tissue to be excised.

[0042] It should be noted that the drawings are intended to depict only typical or exemplary embodiments of the invention. Thus, the drawings should not be considered as limiting the scope of the invention. Detailed Description

[0043] The present invention is not limited to the specific embodiments described and may thus be varied. The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit beyond the scope of the appended claims. Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Finally, although the embodiments of the present invention are specifically described with reference to medical devices and systems and surgical procedures for excising tissue of the digestive system, it should be understood that such medical devices and methods may be used to excise tissue of the abdominal cavity, gastrointestinal system, thoracic cavity, urinary and reproductive tracts, etc. In addition, various medical procedures may benefit from the presently disclosed medical devices and procedures, including, for example, endoscopic submucosal dissection (ESD), peroral endoscopic myotomy (POEM), cholecystectomy, and video-assisted thoracoscopic surgery (VATS). Structures, configurations, and deployment methods may find utility beyond the anatomical for fixation, manipulation, and providing a clear field of view.

[0044] As used herein, the term "distal" refers to the end that is farthest from the medical professional when the device is introduced into the patient's body, while the term "proximal" refers to the end that is closest to the medical professional when the device is introduced into the patient's body.

[0045] As used herein, the term "tissue retraction" or "retraction" refers to the ability to control the position of tissue during an anatomical procedure. For example, "retraction" may allow an excised portion of a target tissue to be secured and lifted from the plane of excision to improve visualization of the remaining (i.e., unexcised) target tissue, while also applying tension to the target tissue to more precisely manipulate an anatomical element.

[0046] As used herein, the term "target tissue" refers to unhealthy, diseased (i.e., neoplastic, pre-neoplastic, etc.) or other undesirable portions of tissue that may be healthy or unhealthy. "Target tissue" may also include tissue suspected of being unhealthy or diseased that requires surgical removal to verify its disease state by biopsy. It should be understood that surgical excision of "target tissue" typically includes removing a portion of the surrounding healthy tissue along the margins of the "target tissue" to ensure complete removal and minimize the likelihood of "target tissue" cells remaining or migrating to other body locations.

[0047] The embodiments described herein may have the same procedural steps or components as the currently pending and commonly owned U.S. Provisional Patent Application Serial No. 62 / 402,649, the disclosure of which is incorporated herein by reference in its entirety, or the procedural steps or components as disclosed therein may be useful.

[0048] In one embodiment, the present invention provides a tissue retraction device that improves visualization and access to a target tissue by retracting and securing an excised portion of the target tissue, including not occupying and / or obstructing the working channel of an endoscope. As Figure 1 shown, in one embodiment, an endoscope 110 may deliver the tissue retractor of the present invention and position it at the site of the target tissue 114. One embodiment may include an elongate flexible element 102 within a delivery catheter 112. The elongate flexible element 102 may be pre-loaded within the delivery catheter 112, or the elongate flexible element 102 may be loaded into the delivery catheter 112 by translating the elongate flexible element 102 distally within the endoscope 110 using a pusher member.

[0049] Figure 2A and 2B shows an embodiment of an elongate flexible element 202. The elongate flexible element 202 may include a body portion 204 having a body width 208 that is wider than an end width 210 of an end portion 206. The body portion 204 may be solid or have missing segments to use less material in manufacture or to provide a scaffold to the structure of the body portion 204. Figure 2A depicts the elongate flexible element in a constrained, generally planar configuration, while Figure 2BDepicts an elongate flexible element in a relaxed, unconstrained arcuate configuration. The relaxed arcuate configuration can be generated by elastic or plastic deformation of the elongate flexible element 202 during manufacture. Depending on the material and the manufacturing method of the material memory, a generally planar configuration may not require constraint. For example, the elongate flexible element 202 can be heat treated to stabilize in either or both configurations such that it presents one relaxed configuration at one temperature and converts to a second relaxed configuration upon heating, etc. The elongate flexible element can include a variety of lengths, depending on the application in which it is used. For example, in a gastrointestinal application, the end-to-end length of the elongate flexible element when constrained can be about 2.8 inches (about 7.11 cm) and about 2.5 inches (about 6.35 cm) when deployed into the target tissue, before conversion to the arcuate configuration.

[0050] The tissue retraction system of the present invention, such as Figures 3A to 3C The illustrated embodiment can include a delivery catheter that includes an inner tubular element 308 slidably and rotatably disposed within an outer sheath 316. The inner tubular element 308 can include a lumen 310. The lumen 310 slidably receives the elongate flexible element 302. The lumen 410 can extend along a portion or the entire length of the inner tubular element 408. The cross-section of the lumen can include a first portion 312 and a second portion 314. The first portion 312 accommodates or can uniformly match the width of the body portion 304, while the second portion 314 accommodates or can uniformly match the width of the end portion 306. When the elongate flexible element 302 is within the lumen 310 of the inner tubular element, the elongate flexible element 302 can be constrained in a generally planar configuration. The body portion 304 of the elongate flexible element 302 can be placed generally flat within the first portion 312 of the lumen 310. The end portion 306 can include at least one tissue anchor within the second portion 314 of the lumen 310 that is radially constrained by the outer sheath 316. When the body portion 304 remains in a generally planar configuration within the first portion 312 of the lumen and the end portion 306 is radially constrained by the outer sheath 316, as Figure 3B shown, the elongate flexible element 302 can be slidably translated within the lumen 310. In this embodiment, the outer sheath 316 includes a slot 318 extending along its longitudinal axis. The length of the slot can vary up to a length that includes the entire length of the elongate element. The width of the slot 318 is greater than the end portion at least at some point toward the distal end of the slot, but can be generally similar to the width of the end portion 306 of the elongate flexible element 302 (e.g., only slightly larger compared thereto). Since the outer sheath 316 inhibits the end portion 306 from extending radially outward, when the slot 318 is axially rotated into alignment with the second portion 314 of the lumen 310, the outer sheath 316 can release the end portion 306, as Figure 3C shown.

[0051] A healthcare professional can position a delivery catheter (i.e., outer sheath 316 and inner tubular element 308) that includes an elongate flexible element 302 proximate to the target tissue that he or she desires to retract. This positioning can place the end portion 306 of the elongate flexible element 302 near the boundary of the target tissue 320 that the healthcare professional has begun or plans to excise. Once the end portion 306 is adjacent the desired location, the healthcare professional can slide and / or rotate the outer sheath 316 relative to the inner tubular element 308 such that the slot 318 is aligned with the second portion 314 of the lumen 310 and release the end portion 306 from within the outer sheath 316 into the target tissue 320. Upon rotation and / or sliding of the outer sheath 316 relative to the inner tubular element 308, the end portion 306 of the elongate flexible element 302 can be released from the lumen 310, and / or by using a pusher member proximal to the elongate flexible element 302 within the lumen 310, the elongate flexible element 302 can be released within the lumen 310 by translating distally. When exposed to the slot 318, the distal end portion 306 can be released simultaneously with the proximal end portion, or the distal end portion 306 can be released into the target tissue 320 prior to the proximal end portion. By first being exposed to the slot 318 of the outer sheath 316 and by further translating the pusher member (and thus translating the elongate flexible element 302), the pusher member can translate the distal end portion 306 out of the lumen 310 and subsequently the proximal end portion can be released into the target tissue 320, similar to how the distal end portion 306 is released by being exposed to the slot 318.

[0052] Alternatively, the distal end portion 306 can be released into the distal portion of the target tissue 320 to engage the distal portion of the target tissue 320 by exposing the distal end portion 306 to the slot 318 of the outer sheath 316 and / or using a pushing member to translate the elongate flexible element 302 distally to expose the end portion 306. With the distal end portion 306 engaged with the target tissue 320 and the proximal end portion remaining within the lumen 310, the inner tubular element 308 and / or the outer sheath 316 can be retracted until the proximal end portion of the elongate flexible element 302 is exposed to the slot 318 and released into the target tissue 320. This can also be achieved with an alternative outer sheath 316 without the slot 318 by sliding the outer sheath 316 and the inner tubular element 308 relative to each other until the end portion 306 is translated out of the outer sheath 316 to engage the target tissue. This can also be achieved by using a pushing member to translate the elongate flexible element 302 through the lumen 310. The distal end portion 306 of the elongate flexible element 302 remains embedded in the target tissue 320 as the inner tubular element 308 and / or the outer sheath 316 retract, such that the remaining portion of the elongate flexible element 302 within the lumen 310 is translated out of the lumen 310, thereby engaging the proximal portion of the target tissue 320 with the proximal end portion of the elongate flexible element 302. With the elongate flexible element 302 delivered in place, the delivery catheter can then be retracted proximally away from the target tissue 320, as Figure 3D shown. The medical professional can then excise the target tissue 320 while the elongate flexible element 302 assumes an arcuate configuration due to being unconstrained, thereby cutting the target tissue from the remaining tissue, as Figure 3E shown.

[0053] As Figure 4A and 4B shown, an embodiment of the tissue retraction system of the present invention can include a slot 418 at the distal end of the outer sheath 416 that extends only a short distance (e.g., less than the length of the elongate flexible element) along the longitudinal axis of the outer sheath 416. When the medical professional positions the distal end of the delivery catheter (i.e., the outer sheath 416 and the inner tubular element 408) at a desired location proximate to the target tissue with respect to the distal end portion 406 of the elongate flexible element 402, the outer sheath 416 can be rotated and / or slid relative to the inner tubular element 408 such that the slot 418 mates with the second portion 414 of the lumen 410, thereby releasing the distal end portion 406 of the elongate flexible element 402 into the target tissue. This can also be achieved with an alternative outer sheath 416 without the slot 418 by sliding the outer sheath 416 and the inner tubular element 408 relative to each other until the distal end portion 406 is translated out of the outer sheath 416 to engage the target tissue. This can also be achieved by using a pushing member to translate the elongate flexible element 402 through the lumen 410. Figure 4ADepicts an inner tubular element 408 having a lumen 410, the cross-section of the lumen 410 having a first part and a second part that together form a T-shape. Figure 4B Depicts an inner tubular element 408 having a lumen 410, the cross-section of the lumen 410 having a first part that is C-shaped and a second part that is tangentially open to the perimeter of the inner tubular element. The lumen 410 may extend along a part or the entire length of the inner tubular element 408. Due to the slot 418 being at the distal end of the outer sheath 416, the proximal end of the elongate flexible element 402 remains constrained within the lumen 410 against the outer sheath 416. Since the distal end portion 406 is embedded within a first part of the target tissue and the proximal end of the elongate flexible element 402 remains within the lumen 410, a medical professional can place the proximal end portion of the elongate flexible element 402 at a desired location proximate to a second part of the target tissue while the end portion remains within the inner tubular element 408. The medical professional can then translate the outer sheath 416 proximally relative to the inner tubular element 408 (and / or translate the inner tubular element 408 distally relative to the outer sheath 416) such that the proximal end of the elongate flexible element 402 aligns with the slot 418, thereby releasing the proximal end into the second part of the target tissue. Alternatively or additionally, the element 402 can be pushed distally using a pusher member while optionally pulling back the outer sheath 416 or the inner tubular element 408 and the outer sheath 416, or the inner tubular element 408 and the outer sheath 416 can be retracted while keeping the elongate flexible element 402 from moving proximally with the pusher member, in each case until the proximal end reaches the slot 418 and is released.

[0054] The tissue retraction system of the present invention is as Figure 5The illustrated embodiment may include a slot 518 extending along the longitudinal axis of the outer sheath 516, where a wider portion at the distal end of the outer sheath 516 tapers to a narrower end 522 of the slot 518 at the proximal portion of the outer sheath 516. The wider end 520 of the slot 518 may be wider than the end 506 of the elongate flexible element 502 (and / or wider than the second portion 514 of the lumen 510 of the inner tubular element 508), while the width of the narrow end 522 of the slot 518 may be just sufficient to accommodate the end 506 of the elongate flexible element 502 (and / or as wide as the second portion 514 of the lumen 510). A medical professional may place the elongate flexible element 502 within the inner tubular element 508 and within the outer sheath 516 such that the distal end 506 of the elongate flexible element 502 is adjacent to a first portion of the target tissue, and rotate and / or slide the outer sheath 516 relative to the inner tubular element 508. Since the wider end 520 of the slot 518 is wider than the proximal end 522, the distal end portion 506 of the elongate flexible element 502 will be released from the wider end 520 of the slot 518 before the proximal end portion 506 located at the narrow end 522 of the slot 518. In this position, the distal end 506 of the elongate flexible element 502 will deploy and engage the first portion of the target tissue, while the proximal end of the elongate flexible element 502 remains constrained by the outer sheath 516. In this position, the medical professional may position the proximal end of the elongate flexible element 502 adjacent to a second portion of the target tissue. The medical professional may then continue to rotate and / or slide the outer sheath 516 such that the narrow end 522 of the slot 518 mates with the proximal end of the elongate flexible element 502, or the proximal end reaches the wider end 520 of the slot 518 (in the case of sliding), thereby releasing it into the second portion of the target tissue.

[0055] A tissue retractor system such as Figures 6A to 6C The illustrated embodiment includes an elongate flexible element 602, which is a bistable spring. Such an elongate flexible element 602 may have two configurations. The generally planar configuration of the elongate flexible element 602 is shown in Figure 6A where the cross-section of the body 604 is radially bowed in a first direction, and the body 604 is straight along its longitudinal axis. The bowed configuration of the elongate flexible element 602 is shown in Figure 6B where the cross-section of the body 604 is radially bowed in a second direction opposite the first direction, and the body 604 is longitudinally bowed. The distal and proximal ends 606 of the elongate flexible element 602 are configured to engage the target tissue. The body 604 of the elongate flexible element 602 is wider than the ends 606. In this embodiment, the body 604 has a curved side extending radially from the longitudinal axis and does not require confinement in the Figure 6A generally planar configuration shown in Figure 6AThe elongate flexible element 602 in a generally planar configuration is converted to Figure 6B an arcuate configuration.

[0056] Referring to Figure 6C , Figure 6A and 6B embodiments of the elongate flexible element 602 may be disposed in the lumen 610 of the inner tubular element 608 in a generally planar configuration as in Figure 6A . The body 604 of the elongate flexible element 602 may be slidably disposed within a first portion 612 of the lumen, while the end 606 of the elongate flexible element 602 may be slidably disposed within a second portion 614 and constrained by the inner wall of the outer sheath 616. Slots 618 in the outer sheath 616 may be rotated and / or slid to provide a path that is at least partially aligned with the second portion 614 of the lumen 610 to deploy the end 606 of the elongate flexible element 602. The profile of the first portion 612 may be configured to match the profile of the elongate flexible element 602.

[0057] Embodiments of the tissue retractor device of the present invention are shown in Figures 7A to 7D and may include a tubular element 700 having a lumen 710 therethrough that slidably receives the elongate flexible element of the present invention. The body portion of the elongate flexible element may be disposed within a wider first portion 712 of the lumen 710, while the end of the elongate flexible element may be disposed within a narrower second portion 714 of the lumen 710. The first portion 712 remains uniform throughout the lumen 710, while the second portion 714 has a short cross-sectional depth ( Figure 7B ) at the proximal end of the tubular element 700, which transitions to a greater cross-section ( Figure 7C ) toward the distal end of the tubular element 700. The most distal section of the lumen 710 has a cross-section ( Figure 7D ) where the second portion 714 opens to the periphery of the tubular element 700. The end of the elongate flexible element configured to engage tissue is slidably disposed within the lumen 710 and constrained within the second portion 714. Translating the elongate flexible element proximally through the lumen 710 (e.g., by using a pusher member) subjects the distal end of the elongate flexible element to a transition cross-section of the lumen 710, e.g., Figure 7C , where the second portion 714 becomes greater to begin deployment of the end of the elongate flexible element. As the end of the elongate flexible element configured to engage the target tissue translates within the second portion 714 of the lumen 710 from a short cross-section, e.g., Figure 7B , to a greater cross-section that opens to the periphery of the tubular element 700, e.g., Figure 7D, the elongate flexible element becomes unconstrained and deploys into a first portion of the target tissue at the distal end of the tubular element 700. The elongate flexible element may continue to be pushed distally out of the tubular element 700 such that as the elongate flexible element translates from the proximal end to the distal end of the lumen 710, the distal end also becomes unconstrained and deploys from a second portion 714 of the lumen into a second portion of the target tissue. Alternatively, the lumen 710 may not have a transition cross-section as shown in Figure 7C but instead suddenly transitions from Figure 7B to Figure 7D . Further, while the cross-section of the lumen 710 is shown as generally T-shaped in Figures 7A to 7D , the cross-section may alternatively present a generally C-shaped cross-section, such as that shown in Figure 4B , which transitions from a shorter "D-shaped" cross-section located at the proximal portion of the inner tubular element 700 to a C-shaped cross-section located at the distal portion of the inner tubular element 700.

[0058] Embodiments of the elongate flexible element may include a plurality of mechanisms configured to engage tissue and prevent the elongate flexible element from disengaging or twisting away from the target tissue. Figures 8A to 8D Some examples are shown. These mechanisms may be provided along an end portion 806 of the elongate flexible element 802 and / or along a body portion 804 to assist in tissue engagement. The tissue engagement mechanisms may engage the tissue individually or together when the end portion 806 also engages the tissue and / or when the body portion 804 approaches the tissue. Figure 8A Barbs 808 are shown along the elongate flexible element 802, including barbs 808 at the end of the end portion 806 that point in one direction, while other barbs 808 on the end portion 806 that are not at the end point in the opposite direction. Additionally, barbs 808 are shown along the body portion 804. Figure 8B Hooks 808 are shown on the end portion 806 and on the body portion along one side of the elongate flexible element 802. The hooks 808 may easily pierce the target tissue, allowing the wider portion of the tip to engage the target tissue as the hooks 808 are pushed deeper into the target tissue, while the second tip at the opposite wider portion makes it difficult to remove the hooks 808 from the target tissue. Figure 8C Bilateral hooks 808 are shown on the end portion 806 of the elongate flexible element 802, which provide a sharper edge to pierce and embed into the target tissue. Figure 8D Hooks 808 are shown on opposite surfaces of the end portion 806 of the elongate flexible element 802 rather than those shown in Figure 8B . These hooks and barbs in various combinations, configurations, and orientations may be used with any elongate flexible element of the present invention depending on the desired tissue effect.

[0059] In one embodiment, the present invention provides as shown in Figure 9AThe tissue retraction system shown uses an endoscope 910 to deliver and position a delivery catheter 912 containing at least one tissue fastener 914 that transports an elongate flexible element 902 to a site of target tissue 920.

[0060] Examples of the elongate flexible element 902 can include ends configured to be engaged by the tissue fastener 914, as Figure 9B shown. In Figure 9B , these ends include loops 904 that can be engaged by hooks 916 on the tissue fastener 914. The length of the loop 904 can be set such that the tissue fastener 914 can be easily manipulated (e.g., rotated, flipped, etc.) while still engaging the loop 904. Although the loop 904 is shown as a closed loop, it can alternatively be other shapes, such as, for example, an arm or a hook. Although each of the two ends is shown as having a loop 904, one end can have a loop 904 while the other end can have a pre-attached tissue fastener 914 without a loop.

[0061] Referring to Figure 9C , by engaging the proximal loop 904 with the tissue anchor 914 (in this embodiment, with the hook 916) and loading the elongate flexible element 902 from the loop to the tissue fastener 914 into the delivery catheter 912, Figure 9A and 9BThe system in can be introduced into a target tissue site. The loop 904 can have different shapes, and the hooks 916 can be configured in different ways, as long as the tissue fastener 914 can engage and fix the elongate flexible element 902 to the target tissue site. The elongate flexible element 902 has an arcuate configuration along its longitudinal axis when unconstrained. A generally straight control line 908 is disposed within a lumen created by the guide member 922 along the elongate flexible element 902, whereby the control line constrains the elongate flexible element 902 in a generally planar configuration when deployed through the lumen of the guide member. The control line 908 can include a material and / or thickness that is stiffer and / or greater than the material and / or thickness of the remainder of the elongate flexible element 902. Although the guide member 922 having a lumen for the control line is depicted as flat and rectangular, it should be understood that it can take on a variety of shapes, such as, for example, circular, semi-circular, oval, square, hybrid shapes, etc. Additionally, the elongate flexible element 902 can include lengths in a variety of constrained configurations (e.g., approximately 6.0 inches (approximately 152 mm); approximately 5.0 inches (approximately 127 mm); approximately 4.0 inches (approximately 101.6 mm); approximately 3.0 inches (approximately 76.2 mm); approximately 2.75 inches (approximately 69.85 mm); approximately 2.0 inches (approximately 50.8 mm); approximately 1.5 inches (approximately 38.1 mm); approximately 1.0 inch (approximately 25.4 mm)). To set up the system for delivery, the distal end of the elongate flexible element 902 not engaged by the tissue fastener 914 can first be loaded into the delivery catheter 912 such that the distal end is distal to the tissue fastener 914 connected to the elongate flexible element at the proximal end. Thus, the proximal end follows the remainder of the elongate flexible element 902 within the delivery catheter 912. The flexible arcuate portion 906 (in this embodiment, a pair of elements in an expanded configuration extending generally away from each other in a longitudinal plane) transitions to a collapsed configuration while being constrained within the delivery catheter. The tissue fastener 914 can be translated distally within the delivery catheter 912, which also pushes the elongate flexible element 902 distally through the delivery catheter 912.

[0062] Alternatively, the tissue fastener 914 can be loaded into the delivery catheter 912 distal to the elongate flexible element 902. In the setup of this alternative embodiment, as the tissue fastener 914 is translated distally, the tissue fastener 914 pulls the elongate flexible element 902 distally. As shown in the embodiment of Figure 9C the tissue fastener can translate the elongate flexible element 902 out of the delivery catheter by pushing distally. Once the arcuate portion 906 exits the delivery catheter, it is no longer constrained in the collapsed configuration and can expand to the expanded configuration. Since the elongate flexible element 902 is engaged by the hooks 916 of the tissue fastener 914 at the proximal loop 904, the movement of the tissue fastener 914 controls the movement of the elongate flexible element 902. The elongate flexible element 902 can be maneuvered toward the target tissue 920.

[0063] Referring to Figure 9D , Figure 9C the tissue retractor system shown therein, the elongated flexible element 902 can be translated over the target tissue 920 by translating the tissue fastener 914 engaged at the proximal end of the flexible element 902 toward the proximal portion of the target tissue 920 after exiting the catheter. Then, the tissue fastener 914 engaging the proximal end of the elongated flexible element 902 can be fastened to the proximal portion of the target tissue 920. Even when attached to the elongated flexible element 902, the fastener 914 can rotate freely so as to optimally position the fastener 914 to engage the target tissue 920 and position the elongated flexible element 902 across the target tissue 920. When the tissue fastener 914 is fastened to the target tissue 920, the distal end of the elongated flexible element 902 hangs freely but is also close to the desired location on the target tissue 920 for tissue retraction (e.g., the distal portion of the target tissue).

[0064] Referring to Figure 9E , Figures 9A to 9D the tissue retractor system can introduce additional tissue fasteners 914 to engage the distal loop 904 of the elongated flexible element 902. The healthcare professional can introduce the additional tissue fasteners 914 through the working channel of the endoscope by using the delivery catheter 912. Alternatively, the same delivery catheter can be reloaded with new fasteners 914 and / or a separate delivery catheter 912 can be used. The tissue fasteners 914 can include hooks 916 to engage the distal loop 904. As an example, the delivery catheter 912 and the tissue fasteners 914 can be modeled along the wire of the RESOLUTION TM clip device sold by Boston Scientific Corporation. Variations of these and other devices and related components and features of the devices and fasteners that may be applicable to the present invention can be found in U.S. Applications 14 / 701,157 (US2015023080A1) and 13 / 463,560 (US20130123807A1), which are incorporated herein by reference. The fasteners can be deployed to be engaged by the hooks 916 with the loop 904 before being locked into position in the target tissue 920. The tissue fasteners 914 can disengage from the delivery catheter 912 and remain with the elongated flexible element 902. To assist in manipulating the elongated flexible element 902, the loop 904 can be larger than the tissue grasping portion 915 of the tissue fastener 914 such that when the healthcare professional is positioning the elongated flexible element 902, the loop 904 can flip to the opposite side of the tissue fastener 914.

[0065] The control line 908 may include a visual marker 918 that may be readily visible to a medical professional to indicate the position of the control line 908 and the proximal portion of the elongate flexible element 902. The marker may be a colored body disposed on the control line 908, a radiopaque material such that it is visible on fluoroscopy, or may be a marker fabricated into the control line 908 (e.g., scored, etched, imprinted, laser etched, etc.). The proximal end of the control line 908 may be bent away from the elongate flexible element 902 such that the marker 918 is unobstructed for even better visibility. This bending of the control line 908 also aids in gripping the control line 908 for removal. The marker may have an expanded profile, such as spherical, compared to the remainder of the control member, to be more readily gripped by a tool inserted through the catheter and / or scope for removal of the control line from the elongate element.

[0066] Once the second tissue fastener 914 is engaged to the distal loop 904, the tissue fastener 914 may be manipulated (e.g., rotated, flipped, etc.) to position the elongate flexible element 902 along the target tissue 920 as desired. Once the elongate flexible element 902 is in place, additional tissue fasteners may be engaged to a second portion (e.g., distal portion) of the target tissue 920, thereby fixing the elongate flexible element 902 to the target tissue. The delivery catheter 912 may then release the second tissue fastener 914. Prior to excising the target tissue, a medical professional may convert the elongate flexible element 902 to its arcuate configuration along its longitudinal axis. This may allow for partial tissue retraction during the excision procedure. Alternatively, the elongate flexible element 902 may remain in its generally planar configuration before and / or during excision of the target tissue. To convert the elongate flexible element 902 to the arcuate configuration, a grasping device may be introduced to a site of the target tissue 920. The grasping device may be manipulated toward the marker 918 on the bent portion of the control line 908. Referring Figure 9F , the control line 908 may be grasped and pulled out of the guide member 922. In the absence of the control line 908, the elongate flexible element 902 may transition from its generally planar configuration to its arcuate configuration along its longitudinal axis, thereby inducing a retraction force on the target tissue 920.

[0067] Referring Figure 9G shows Figures 9A to 9FA system in which the control line 908 of the elongate flexible element 902 is removed such that the elongate flexible element 902 is in an arcuate configuration. In this configuration, the elongate flexible element 902 experiences a retraction force on each tissue fastener 914 and thus also on the target tissue 920. The resection device 924 can be introduced through the working channel of the endoscope 910 to resect the perimeter around the target tissue 920. This resection of the target tissue 920 releases the target tissue 920 from the surrounding tissue, allowing the target tissue 920 to yield to the retraction force of the elongate flexible element 902 in the arcuate configuration. Although the distal and proximal ends of the target tissue 920 are shown as being elevated by the fasteners 914 and the loop 904, additional arms can extend from the elongate flexible element 902 in a direction extending across the target tissue 920 (such as orthogonal to the elongate flexible element) and include loops 904 that can be engaged by the hooks 916 on the tissue fasteners 914. The arcuate portion 906 can extend radially outward from the longitudinal axis in a plane generally parallel to the target tissue. As the target tissue 920 begins to retract from the surrounding tissue, the arcuate portion 906 can provide additional surface area and resistance to the side portions of the target tissue 920 to retract and fold the elongate flexible element 902. Complete resection of the perimeter around the target tissue 920 disconnects it from the surrounding tissue, which allows the elongate flexible element 902 to fully lift and retract the resected target tissue 920 from the surrounding tissue. The target tissue 920 and the tissue retraction system can be removed from the body by a medical professional or left in the body to pass through the gastrointestinal tract.

[0068] In a first generally planar or flat configuration of any embodiment, a portion or all of the body of the elongate flexible element can be positioned to contact the tissue surface. In one embodiment, the elongate flexible element can include a width and a thickness, where the width exceeds the thickness such that the elongate flexible element resists the tendency to roll or twist during a resection procedure. For example, the elongate flexible element can include a width (e.g., about 0.070 inches (about 1.778 mm); about 0.065 inches (about 1.651 mm); about 0.060 inches (about 1.524 mm); about 0.055 inches (about 1.397 mm); about 0.050 inches (about 1.27 mm)) that is greater than the thickness (e.g., about 0.040 inches (about 1.016 mm); about 0.035 inches (about 0.889 mm); about 0.030 inches (about 0.762 mm); about 0.025 inches (about 0.635 mm); about 0.020 inches (about 0.508 mm)), and in some cases, the width can be about twice as large as the thickness. The elongate flexible element can be made of, for example, a variety of elastic biocompatible materials, including metals and metal alloys such as platinum, tungsten, titanium, stainless steel, nickel, and nickel-titanium alloys (e.g., nitinol); polymers such as acrylate-based polymers, polyurethane-based polymers, polynorbornene-based polymers, and polylactide-based polymers and any combination thereof.

[0069] It should be understood that the "force" stored in such a material when in a constrained configuration allows the elongate flexible element to exert and maintain an upward lifting / retracting pressure against the tissue into which it is inserted. The natural tendency of the elongate flexible element to move (i.e., return) from a flat or planar shape in a first configuration to an arcuate (e.g., circular or hemispherical) shape in a second configuration allows the excised portion of the target tissue to be lifted or elevated above the resection plane, such that the unexcised target tissue can be more readily visualized and more effectively resected. The shape of the second configuration can be controlled during the manufacture of the elongate flexible element so as to impart or set the desired memory of the elongate flexible element material when in a relaxed, unconstrained position.

[0070] A method for retracting excised tissue can include a healthcare professional advancing a delivery catheter through the working channel of an endoscope to a position adjacent to the target tissue such that the distal end of the delivery catheter is proximal to a first portion of the target tissue. The healthcare professional can advance an elongate flexible element through the working channel of the delivery catheter such that the distal end of the elongate flexible element extends beyond the distal end of the delivery catheter to engage the first portion of the target tissue. The healthcare professional can retract the delivery catheter proximally such that the proximal end of the elongate flexible element moves beyond the distal end of the delivery catheter. The healthcare professional can push the distal end of the delivery catheter against the proximal end of the elongate flexible element such that the proximal end of the elongate flexible element engages a second portion of the target tissue. The healthcare professional can rotate and / or slide the outer sheath of the delivery catheter relative to the inner tubular element of the delivery catheter, thereby releasing the distal end of the elongate flexible element into the first portion of the target tissue and subsequently retracting the proximal end of the elongate flexible element into the second portion of the tissue. The healthcare professional can push a tissue resection element through the working channel of the endoscope and perform a resection along the edge of the target tissue as the elongate flexible element moves from the first configuration to the second configuration.

[0071] The devices (including other accessories) according to the described embodiments and according to other embodiments of the present invention can be used, either alone or in a system or kit or as part of a method or surgical procedure, in body cavities, lumens, ducts, vessels, organs, and the like.

[0072] For those of ordinary skill in the art, variations, modifications, and other implementations of the present invention can be achieved in addition to the various embodiments described herein. Accordingly, the present invention is not limited by the foregoing illustrative description but by the claims.

Claims

1. An organization retraction system, comprising: One or more tissue fasteners; An elongate flexible element having a first end, a second end, and a flexible arcuate portion between the first end and the second end; And A delivery catheter configured to deliver the elongate flexible element to a target tissue site, wherein at least one of the one or more tissue fasteners is attached to one end of the elongate flexible element; Wherein: At least one of the first end and the second end of the elongate flexible element is configured to be engaged by at least one of the one or more tissue fasteners and delivered therewith; One of the first end and the second end of the elongate flexible element is mounted on the tissue fastener; and The flexible arcuate portion of the elongate flexible element includes a pair of generally parallel elements, each of the pair of generally parallel elements having a flexible bowed portion between parallel end portions, the flexible bowed portion being convertible from a collapsed configuration within the delivery catheter to an expanded configuration extending generally away from each other when unconstrained.

2. The tissue retraction system according to claim 1, wherein at least one of the one or more tissue fasteners has a first jaw and a second jaw movable relative to each other.

3. The tissue retraction system according to claim 2, wherein at least one of the first jaw and the second jaw of the tissue fastener is configured to be coupled to one of the ends of the elongate flexible element.

4. The tissue retraction system according to claim 1, wherein at least one of the one or more tissue fasteners includes a hook configured to engage an end of the elongate flexible element.

5. The tissue retraction system according to claim 1, wherein at least one end of the elongate flexible element configured to be engaged by the tissue fastener has a loop.

6. The tissue retraction system according to claim 5, wherein at least one of the one or more tissue fasteners includes a hook configured to engage the loop on the elongate flexible element.

7. The tissue retraction system according to claim 5, wherein the loop on the elongate flexible element has a length that allows manipulation of the tissue fastener engaged therewith relative to the elongate flexible element while still engaging the loop.

8. The tissue retraction system according to claim 1, wherein the elongate flexible element is loaded within the delivery catheter and one of the one or more tissue fasteners is attached to its end.

9. The tissue retraction system according to claim 1, wherein The delivery catheter has an open distal end; The elongate flexible element is loaded within the delivery catheter, one of its ends being located distally of the flexible arcuate portion and the other of the ends being located proximally of the flexible arcuate portion; and One of the one or more tissue fasteners is connected to the end of the elongate flexible element proximal to the flexible arcuate portion.

10. The tissue retraction system according to claim 1, wherein: The delivery catheter has an open distal end; The slender flexible element is loaded within the delivery catheter, with one of its ends positioned distally of the flexible arcuate portion and the other of the ends positioned proximally of the flexible arcuate portion; and One of the one or more tissue fasteners is connected to the end of the slender flexible element that is distal of the flexible arcuate portion.

11. The tissue retraction system according to claim 1, wherein at least one of the tissue fasteners configured to engage and secure at least one of the first end and the second end of the slender flexible element is movable relative to at least one of the first end and the second end of the slender flexible element.

12. A slender flexible element, comprising: A first slender end; A second slender end; and A flexible arcuate portion having a pair of elements longitudinally extending between the first slender end and the second slender end; Wherein: At least one of the first slender end and the second slender end is configured to be engaged by a tissue fastener to secure the slender flexible element to tissue via the tissue fastener; The slender flexible element is convertible between a generally planar configuration and an arcuate configuration along the longitudinal axis of the slender flexible element, the arcuate configuration being configured to lift the tissue; In a first configuration of the slender flexible element, the pair of elements of the flexible arcuate portion extend away from each other in a plane generally parallel to the plane of the tissue to which the slender flexible element is secured; and In the arcuate configuration of the slender flexible element, the pair of elements of the flexible arcuate portion extend generally away from each other, and the first slender end and the second slender end extend in the curved surface in which the tissue is lifted.

13. The slender flexible element according to claim 12, wherein the slender flexible element is convertible between a generally planar configuration and an arcuate configuration along the longitudinal axis of the slender flexible element.

14. The slender flexible element according to claim 13, wherein the pair of elements of the flexible arcuate portion extend away from the longitudinal axis of the slender flexible element when in the arcuate configuration.

15. The slender flexible element according to claim 12, wherein at least one of the ends of the slender flexible element includes a loop configured to be engaged by a tissue fastener.

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