Devices and methods for tissue retraction

Abstract

The invention relates to the field of tissue anatomy. In particular, the present invention relates to medical devices that lift and retract tissue during an anatomical procedure to improve the visualization of target tissue and mitigate disorders caused by anatomical tools. In particular, the present invention relates to a device that transitions from a constrained configuration to an unconstrained arcuate configuration during an anatomical procedure to secure and retract a resected portion of target tissue.

Description

[0001] This application is a divisional application of application number 201880021271.1, application date 2018.03.28, named "Device and method for tissue retraction", and a divisional application submitted on 2022.1.17 (application number 202210049911.8, named "Device and method for tissue retraction").

[0002] priority

[0003] This application claims the benefit of priority under 35 U.S.C. §119 to U.S. Provisional Patent Application Serial No. 62 / 478,169, filed on March 29, 2017, the entire contents of which are incorporated herein by reference for all purposes. Technical Field

[0004] The present invention relates to the field of tissue dissection. Specifically, the present invention relates to medical devices that elevate and retract tissue during dissection procedures to improve visualization of target tissue and alleviate obstructions caused by dissection tools. In particular, the present invention relates to devices that transition from a constrained configuration to an unconstrained, arcuate configuration to secure and retract a resected portion of target tissue during dissection procedures. Background Art

[0005] Due to poor visualization of the target tissue during dissection, surgical resection of lesions within narrow body passages, such as the digestive tract, can be inefficient and time-consuming. This problem can be exacerbated during surgery because 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 disclosed herein. Summary of the Invention

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

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

[0008] A tissue retractor system may include a first portion of the lumen cross-section of the inner tubular element that may substantially match the width of the body portion of the lumen of the inner tubular element. A system having an elongated flexible element may include a second portion of the lumen cross-section of the inner tubular element that may substantially match the width of the distal and proximal ends of the body portion of the elongated flexible element. One system may include an outer sheath having a slot, whereby rotating one or both of the outer sheath and the inner tubular element relative to each other aligns 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 elongated flexible element to be deployed radially outward from the outer sheath. One system may include an outer sheath having a slot, whereby sliding one or both of the outer sheath and the inner tubular element relative to each other aligns 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 elongated flexible element to be deployed radially outward from the outer sheath. One system may include a sheath having a slot that is wider at the distal end of the sheath than at the proximal end. A system may include an inner tubular element having a second portion of a cross-section that may be open to a periphery of the inner tubular element along a longitudinal axis of the inner tubular element. A system may include an outer sheath having a slot at a distal end, the slot having a width that substantially matches the width of the distal and proximal ends of the elongated flexible element along its length. A system may include an outer sheath having a slot having a width that extends along the longitudinal axis of the outer sheath, and wherein the slot has a width that substantially matches the width of the distal and proximal ends of the elongated flexible element. A system may include a generally T-shaped cross-section of the inner tubular element, and wherein a first portion of the cross-section is configured to slidably receive a body portion of the elongated flexible element, and a second portion of the cross-section is configured to slidably receive the distal and proximal ends of the elongated flexible element. A system may include a generally C-shaped cross-section of the inner tubular element, wherein a first portion of the cross-section is configured to slidably receive the body portion of the elongated flexible element, and a second portion of the cross-section is configured to slidably receive the distal and proximal ends of the elongated flexible element. A system may include a pusher member slidably disposed within a lumen proximal to an elongated flexible element, whereby distal movement of the pusher member extends and translates the elongated flexible element distally. A system may include distal and proximal ends of the elongated flexible element, wherein each end may include one or more tissue anchors selected from the group consisting of tines, prongs, hooks, fingers, barbs, loops, and clips.

[0009] A tissue retractor system may include a plurality of tissue fasteners. A system may include an elongated flexible element having 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 elongated flexible element, wherein the at least one guide member defines a lumen extending therethrough. A system may include a control wire configured to be slidably received within the lumen of the at least one guide member. The elongated flexible element may be transitionable between a first configuration when the control wire is disposed within the lumen of the at least one guide member and a second configuration when the control wire 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 elongated flexible element and at least one tissue fastener.

[0010] A system may include a proximal end of an elongated 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 elongated flexible member being larger than a tissue-grasping portion of each of the plurality of tissue fasteners. A system may include a proximal end of the elongated flexible member having a proximal arm configured to be engaged by one of the plurality of tissue fasteners; and a distal end including a distal arm configured to be engaged by another one of the plurality of tissue fasteners. A system may include an elongated flexible member that may include a pair of generally parallel members in a first configuration, each member 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 extending from a body between the proximal and distal ends of the elongated flexible member. A system may include at least one arm having an end configured to be engaged by a tissue fastener.

[0011] A slender flexible element may include a proximal end and a distal end each having a loop, the loop being configured to be engaged by a tissue fastener. At least one guide member may be attached to the slender flexible element, wherein the at least one guide member defines a lumen extending therethrough. A control wire may be configured to be slidably received within the lumen of the at least one guide member. The slender flexible element may be transitioned between a first configuration when the control wire is disposed within the lumen of the at least one guide member and a second configuration when the control wire is removed from the lumen of the at least one guide member. An elongated flexible element may include, in a first configuration, a pair of generally parallel elements, each element having a flexible arcuate portion extending generally away from each other in a longitudinal plane in a second configuration. An elongated flexible element may include at least one arm extending from a body between the proximal and distal ends of the elongated flexible element. An elongated flexible element may include a guide member having a visual indicia at an end of the guide member. BRIEF 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 intended to be drawn to scale. In the drawings, each identical or nearly identical component is generally represented by a single numeral. For clarity, not every component is labeled in every figure, and not every component of every embodiment of the invention is shown, where illustration is not necessary for one skilled in the art to understand the invention. In the drawings:

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

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

[0015] Figure 2B yes Figure 2A Illustration of the elongated flexible element in an unconstrained configuration.

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

[0017] Figure 3B yes Figure 3A Illustration of the system in a constrained configuration.

[0018] Figure 3C yes Figure 3A and 3B Illustration of the system in FIG, with the outer sheath in the deployed configuration.

[0019] Figure 3D yes Figures 3A to 3C Illustration of the system, deployment of slender flexible elements.

[0020] Figure 3E yes Figures 3A to 3D Illustration of the system and anatomical elements in removing the target tissue to be resected.

[0021] Figure 4A is an illustration of a system having a slot at the distal end of an outer sheath and an inner tubular member having a luminal cross-section with first and second portions together forming a T-shape, in accordance with an embodiment of the present invention.

[0022] Figure 4B is an illustration of a system having a slot at the distal end of an outer sheath and an inner tubular member having a luminal cross section with a first portion formed in a C-shape and a second portion open tangentially to the periphery of the inner tubular member in accordance with an embodiment of the present invention.

[0023] Figure 5is an illustration of a system having a slot along an outer sheath wherein the slot is wider at its distal end than at its proximal end in accordance with an embodiment of the present invention.

[0024] Figure 6A FIG. 1 is a diagram illustrating a bistable spring as an elongated flexible element in a generally planar configuration according to an embodiment of the present invention.

[0025] Figure 6B yes Figure 6A Illustration of the slender flexible element in a generally arcuate configuration.

[0026] Figure 6C yes Figure 6A and 6B Illustration of the elongated flexible element within a delivery catheter.

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

[0028] Figure 7B yes Figure 7A Illustration of a cross section at section 7B.

[0029] Figure 7C yes Figure 7A Illustration of a cross section at section 7C.

[0030] Figure 7D yes Figure 7A Illustration of a cross section at section 7D.

[0031] Figure 8A is an illustration of an elongated flexible member having barbs according to one embodiment of the present invention.

[0032] Figure 8B is an illustration of an elongated flexible member having a hook according to an embodiment of the present invention.

[0033] Figure 8C is an illustration of an elongated flexible member having a hook according to an embodiment of the present invention.

[0034] Figure 8D is an illustration of an elongated flexible member having a hook according to an embodiment of the present invention.

[0035] Figure 9A FIG. 1 is a diagram illustrating a system being deployed according to an embodiment of the present invention.

[0036] Figure 9B yes Figure 9A Illustration of an embodiment of a system in which loops at the ends of an elongated flexible element are engaged by tissue fasteners.

[0037] Figure 9C yes Figure 9A and 9B Illustration of the system in which an elongated flexible element and tissue fastener are being deployed.

[0038] Figure 9D yes Figures 9A to 9C Illustration of a system in which an elongated flexible element is translated to a position above target tissue.

[0039] Figure 9E yes Figures 9A to 9D Illustration of the system in which the second tissue fastener is engaging the loop of the elongated flexible element and also engaging the target tissue.

[0040] Figure 9F yes Figures 9A to 9E Illustration of the system in which the control wires are being removed.

[0041] Figure 9G yes Figures 9A to 9F Illustration of a system in which an anatomical element is removing target tissue to be resected.

[0042] It should be noted that the appended drawings are intended to depict only typical or exemplary embodiments of the invention and are therefore not to be considered limiting of the scope of the invention. DETAILED DESCRIPTION

[0043] The present invention is not limited to the specific embodiments described and is therefore subject to change. The terms used herein are only used for the purpose of describing specific embodiments and are not intended to limit the scope beyond the scope of the appended claims. Unless otherwise specified, all technical terms used herein have the same meaning as those generally understood by those skilled in the art to which the present invention belongs. Finally, although embodiments of the present invention are described with specific reference to medical devices and systems and surgical procedures for removing tissues of the digestive system, it should be understood that such medical devices and methods can be used for removing tissues of the abdominal cavity, gastrointestinal system, thoracic cavity, urinary and reproductive tracts, etc. In addition, various medical surgeries can benefit from the currently disclosed medical devices and surgeries, including, for example, endoscopic submucosal dissection (ESD), peroral endoscopic myotomy (POEM), cholecystectomy and video-assisted thoracoscopic surgery (VATS). In order to fix, manipulate and provide a clear field of view, the structure and configuration and deployment method can find practicality beyond anatomy.

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

[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" can allow a resected portion of target tissue to be secured and elevated from the resection plane to improve visualization of the remaining (i.e., unresected) target tissue while also applying tension to the target tissue for more precise manipulation of anatomical elements.

[0046] As used herein, the term "target tissue" refers to an unhealthy, diseased (i.e., tumorous, pre-neoplastic, etc.) or other undesirable portion 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 the "target tissue" typically includes removing a portion of the surrounding healthy tissue along the edges of the "target tissue" to ensure complete removal and minimize the possibility of the remaining or displaced "target tissue" cells from migrating to other body locations.

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

[0048] In one embodiment, the present invention provides a tissue retraction device that improves visibility and access to target tissue during dissection procedures by retracting and securing a portion of the target tissue to be removed, including without occupying and / or blocking a working channel of an endoscope. Figure 1 As shown, in one embodiment, an endoscope 110 can deliver a tissue retractor of the present invention and position it at a target tissue site 114. One embodiment can include an elongated flexible element 102 within a delivery catheter 112. The elongated flexible element 102 can be pre-loaded within the delivery catheter 112 or loaded into the delivery catheter 112 within the endoscope 110 by translating the elongated flexible element 102 distally using a push member.

[0049] Figure 2A and 2B 1. An embodiment of an elongated flexible member 202 is shown in FIG. The elongated flexible member 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 sections to use less material in manufacturing or to provide support to the structure of the body portion 204. Figure 2A depicts an elongated flexible element in a constrained, generally planar configuration, and Figure 2BThe elongated flexible element is depicted in a relaxed, unconstrained, arched configuration. The relaxed arched configuration can be generated by elastic or plastic deformation of the elongated flexible element 202 during manufacturing. Depending on the material and the manufacturing method of the material memory, a generally planar configuration may not require constraint. For example, the elongated flexible element 202 can be heat treated to stabilize in either or both configurations such that it exhibits a relaxed configuration at one temperature and is converted to a second relaxed configuration upon heating, etc. The elongated flexible element can include a variety of lengths, depending on the application in which it is used. For example, in gastrointestinal applications, before being converted to the arched configuration, the elongated flexible element can have an end-to-end length of about 2.8 inches (about 7.11 centimeters) when constrained and about 2.5 inches (about 6.35 centimeters) when deployed in the target tissue.

[0050] The tissue retraction system of the present invention is as follows Figures 3A to 3C The illustrated embodiment may include a delivery catheter comprising an inner tubular member 308 slidably and rotatably disposed within an outer sheath 316. The inner tubular member 308 may include a lumen 310. The lumen 310 slidably accommodates the elongated flexible member 302. The lumen 410 may extend along a portion or the entire length of the inner tubular member 408. The lumen may include a first portion 312 and a second portion 314 in cross-section. The first portion 312 accommodates or may uniformly match the width of the body portion 304, while the second portion 314 accommodates or may uniformly match the width of the end portion 306. When the elongated flexible member 302 is within the lumen 310 of the inner tubular member, the elongated flexible member 302 may be constrained in a generally planar configuration. The body portion 304 of the elongated flexible member 302 may lie generally flat within the first portion 312 of the lumen 310. The end portion 306 may include at least one tissue anchor within the second portion 314 of the lumen 310, constrained in a radial direction by the outer sheath 316. When the body portion 304 maintains a generally planar configuration within the first portion 312 of the cavity and the end portion 306 is radially constrained by the outer sheath 316, as shown in FIG. Figure 3B As shown, the elongated flexible element 302 can be slidably translated within the cavity 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 elongated 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 elongated flexible element 302 (e.g., only slightly larger than the width thereof). Because the outer sheath 316 restrains the end portion 306 from extending radially outward, when the slot 318 is axially rotated to align with the second portion 314 of the cavity 310, the outer sheath 316 can release the end portion 306, as shown. Figure 3C shown.

[0051] A medical professional can position the delivery catheter (i.e., outer sheath 316 and inner tubular element 308) containing the elongated flexible element 302 proximate the target tissue he or she wishes to retract. This position can place the end portion 306 of the elongated flexible element 302 near the boundary of the target tissue 320 that the medical professional has begun to resect or plans to resect. Once the end portion 306 is proximate the desired location, the medical professional can slide and / or rotate the outer sheath 316 relative to the inner tubular element 308 so that the slot 318 aligns 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. The end portion 306 of the elongated flexible element 302 can be released from the lumen 310 upon rotating and / or sliding the outer sheath 316 relative to the inner tubular element 308, and / or the elongated flexible element 302 can be released by translating distally within the lumen 310 using a pusher member proximal to the elongated flexible element 302 within the lumen 310. 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 before the proximal end portion into the target tissue 320. By first being exposed to the slot 318 of the outer sheath 316, and by further translating the pushing member (and thereby translating the elongated flexible element 302), the pushing member can translate the distal end portion 306 out of the cavity 310, and then the proximal end portion can be released into the target tissue 320, similar to how the distal end portion 306 was released by being exposed to the slot 318.

[0052] Alternatively, by exposing the distal end portion 306 to the slot 318 of the outer sheath 316 and / or using a pushing member to distally translate the elongated flexible element 302 to expose the end portion 306, 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. With the distal portion 306 engaged with the target tissue 320 and the proximal end portion still 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 elongated 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 inner tubular element 308 relative to each other until the end portion 306 translates out of the outer sheath 316 to engage the target tissue. This can also be achieved by using a pushing member to translate the elongated flexible element 302 through the lumen 310. The distal end portion 306 of the elongated flexible element 302 remains embedded in the target tissue 320 when the inner tubular element 308 and / or the outer sheath 316 are retracted, so that the remaining portion of the elongated flexible element 302 within the lumen 310 translates out of the lumen 310, thereby engaging the proximal portion of the target tissue 320 with the proximal end portion of the elongated flexible element 302. With the elongated flexible element 302 delivered in place, the delivery catheter can then be retracted proximally away from the target tissue 320, as shown. Figure 3D The medical professional can then cut the target tissue 320 while the elongated flexible member 302, being unconstrained, transforms into an arcuate configuration, thereby cutting the target tissue from the remaining tissue, as shown in FIG. Figure 3E shown.

[0053] like Figure 4A and 4B As shown, embodiments of the tissue retraction system of the present invention may include a slot 418 at the distal end of the outer sheath 416 that extends only a short distance along the longitudinal axis of the outer sheath 416 (e.g., less than the length of the elongated flexible element). When a 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 proximal to the target tissue relative to the distal end portion 406 of the elongated flexible element 402, the outer sheath 416 may 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 406 of the elongated flexible element 402 into the target tissue. This may also be achieved with an alternative outer sheath 416 without the slot 418 by sliding the outer sheath 416 and inner tubular element 408 relative to each other until the end portion 406 translates out of the outer sheath 416 to engage the target tissue. This may also be accomplished by using a pushing member to translate the elongated flexible element 402 through the lumen 410 . Figure 4AAn inner tubular member 408 is depicted having a lumen 410 having a cross-section with first and second portions that together form a T-shape. Figure 4B An inner tubular member 408 is depicted having a lumen 410 having a cross-section having a first portion formed as a C-shape and a second portion that is tangentially open to the periphery of the inner tubular member. Lumen 410 may extend along a portion or the entire length of inner tubular member 408. Because slot 418 is at the distal end of outer sheath 416, the proximal end of elongated flexible member 402 remains constrained within lumen 410 against outer sheath 416. With distal end portion 406 embedded within the first portion of target tissue and the proximal end of elongated flexible member 402 still within lumen 410, a medical professional can position the proximal end portion of elongated flexible member 402 at a desired location proximate to the second portion of target tissue while the end portion remains within inner tubular member 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) so that the proximal end of the elongated flexible element 402 matches the slot 418, thereby releasing the proximal end into the second portion of the target tissue. Alternatively or additionally, the element 402 can be pushed distally using a pushing 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 holding the elongated flexible element 402 from moving proximally with the pushing 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 follows Figure 5The illustrated embodiment can include a slot 518 extending along the longitudinal axis of the outer sheath 516, wherein 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 can be wider than the end 506 of the elongated flexible member 502 (and / or wider than the second portion 514 of the lumen 510 of the inner tubular member 508), while the narrow end 522 of the slot 518 can be just wide enough to accommodate the end 506 of the elongated flexible member 502 (and / or as wide as the second portion 514 of the lumen 510). A medical professional can place the elongated flexible member 502 within the inner tubular member 508 and within the outer sheath 516 so that the distal end 506 of the elongated flexible member 502 is proximate to the first portion of the target tissue and rotate and / or slide the outer sheath 516 relative to the inner tubular member 508. Because the distal end 520 of the slot 518 is wider than the proximal end 522, the distal end portion 506 of the elongated flexible element 502 will be released from the distal end 520 of the slot 518 before the proximal end portion 506 at the narrow end 522 of the slot 518. In this position, the distal end 506 of the elongated flexible element 502 will be deployed and engage the first portion of the target tissue, while the proximal end of the elongated flexible element 502 is still restrained by the outer sheath 516. In this position, the medical professional can position the proximal end of the elongated flexible element 502 proximate to the second portion of the target tissue. The medical professional can then continue to rotate and / or slide the outer sheath 516 so that the narrow end 522 of the slot 518 matches the proximal end of the elongated 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] Tissue retractor system such as Figures 6A to 6C The embodiment shown includes an elongated flexible element 602 that is a bistable spring. This elongated flexible element 602 can have two configurations. The generally planar configuration of the elongated flexible element 602 is Figure 6A , wherein the cross-section of the body 604 is radially arcuate in a first direction, while the body 604 is straight along its longitudinal axis. Figure 6B , wherein the cross-section of the body 604 is radially arcuate in a second direction opposite to the first direction, while the body 604 is longitudinally arcuate. The distal and proximal ends 606 of the elongated flexible element 602 are configured to engage the target tissue. The body 604 of the elongated flexible element 602 is wider than the ends 606. In this embodiment, the body 604 has curved sides extending radially from the longitudinal axis and does not need to be constrained in the Figure 6A Once the elongated flexible element 602 is in place and the end 606 is engaged in the target tissue, a longitudinal perpendicular force (ie, a radial force) can be applied to the elongated flexible element 602. Figure 6AThe elongated flexible element 602 is generally planar in shape to allow it to be converted to Figure 6B bow-shaped form.

[0056] Reference Figure 6C , Figure 6A and 6B Embodiments of the elongated flexible element 602 may be configured as follows: Figure 6A The generally planar form of the inner tubular member 608 is disposed within the lumen 610 of the inner tubular member 608. The body 604 of the elongated flexible member 602 is slidably disposed within the first portion 612 of the lumen, while the end portion 606 of the elongated flexible member 602 is slidably disposed within the second portion 614 and constrained by the inner wall of the outer sheath 616. The slot 618 on the outer sheath 616 can be rotated and / or slid to provide a path that is at least partially aligned with the second portion 614 of the lumen 610, thereby deploying the end portion 606 of the elongated flexible member 602. The contour of the first portion 612 can be formed to match the contour of the elongated flexible member 602.

[0057] An embodiment of the tissue retraction device of the present invention is shown in Figures 7A to 7D In one embodiment, a tubular member 700 may be provided having a lumen 710 therethrough that is adapted to slidably receive an elongated flexible member of the present invention. The body portion of the elongated flexible member may be disposed within a wider first portion 712 of the lumen 710, while the end portion of the elongated flexible member 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 maintains a short cross-sectional depth ( Figure 7B ), which transitions to a higher cross-section toward the distal end of the tubular element 700 ( Figure 7C ). The distalmost section of the cavity 710 has a cross section ( Figure 7D ), wherein the second portion 714 is open to the periphery of the tubular element 700. An elongated flexible element having an end configured to engage tissue is slidably disposed within the lumen 710, constrained within the second portion 714. Proximally translating the elongated flexible element through the lumen 710 (e.g., by using a pushing member) subjects the distal end of the elongated flexible element to a transitional section of the lumen 710, e.g., Figure 7C , wherein the second portion 714 becomes higher to begin deploying the end of the elongated flexible member. As the end of the elongated flexible member configured to engage the target tissue moves from a short cross-section within the second portion 714 of the cavity 710, e.g., Figure 7B Translation to a higher section open to the periphery of the tubular element 700, e.g. Figure 7D, the elongated flexible element becomes unconstrained and is deployed into the first portion of the target tissue at the distal end of the tubular element 700. The elongated flexible element may continue to be pushed distally out of the tubular element 700 so that as the elongated flexible element translates from the proximal end to the distal end of the lumen 710, the distal end is also unconstrained and is deployed from the second portion 714 of the lumen into the second portion of the target tissue. Alternatively, the lumen 710 may not have a Figure 7C The transition section shown is from Figure 7B Suddenly converted to Figure 7D In addition, although Figures 7A to 7D The cavity 710 is shown as having a generally T-shaped cross section, but the cross section may alternatively exhibit a generally C-shaped cross section, such as Figure 4B As shown in FIG, it transitions from a shorter “D-shape” at the proximal portion of the inner tubular member 700 to a C-shape at the distal portion of the inner tubular member 700.

[0058] Embodiments of the elongated flexible member may include a plurality of mechanisms configured to engage tissue and prevent the elongated flexible member from disengaging or twisting away from the target tissue. Figures 8A to 8D Some examples are shown. These mechanisms can be provided along the end portion 806 of the elongated flexible element 802 and / or along the body portion 804 to facilitate tissue engagement. The tissue engagement mechanisms can engage tissue individually or together when the end portion 806 also engages tissue and / or when the body portion 804 is proximate to the tissue. Figure 8A Barbs 808 are shown along the elongated flexible element 802, including barbs 808 pointing in one direction at the distal end of the end portion 806, while other barbs 808 on the end portion 806 that are not distally pointed in the opposite direction. Figure 8B Hooks 808 are shown on the end portion 806 and on the body portion along one side of the elongated flexible element 802. The hooks 808 can easily penetrate the target tissue, allowing the wider portion of the tip to engage the target tissue as the hook 808 is pushed deeper into the target tissue, while the second tip at the opposite wider portion makes it difficult to remove the hook 808 from the target tissue. Figure 8C Shown are double-sided hooks 808 on the end portion 806 of the elongated flexible element 802, which provide sharper edges to pierce and embed into the target tissue. Figure 8D The hook 808 is shown on the opposite surface of the end portion 806 of the elongated flexible member 802, rather than Figure 8B These hooks and barbs may be used with any of the elongated flexible members of the present invention in various combinations, configurations, and orientations, depending on the desired tissue effect.

[0059] In one embodiment, the present invention provides Figure 9AA tissue retraction system is shown that uses an endoscope 910 to deliver and position a delivery catheter 912 containing at least one tissue fastener 914 that conveys an elongated flexible member 902 toward the site of target tissue 920.

[0060] Embodiments of the elongated flexible member 902 may include ends configured to be engaged by a tissue fastener 914, such as Figure 9B As shown. Figure 9B 904. In the embodiment of the present invention, the ends include loops 904 that can be engaged by hooks 916 on tissue fasteners 914. The length of loops 904 can be configured so that tissue fasteners 914 can be easily manipulated (e.g., rotated, flipped, etc.) while still engaging loops 904. Although loops 904 are shown as closed loops, they can alternatively be other shapes, such as, for example, arms or hooks. Although both ends are shown as having loops 904, one end can have loops 904 while the other end can have a pre-attached tissue fastener 914 without loops.

[0061] Reference Figure 9C , by engaging the proximal loop 904 with the tissue anchor 914 (in this embodiment, with the hook 916 ) and loading the elongated flexible element 902 of the loop-to-tissue fastener 914 into the delivery catheter 912 , Figure 9A and 9BThe system can be introduced into a target tissue site. The loop 904 can have various shapes, and the hook 916 can be configured in various ways, so long as the tissue fastener 914 can engage and secure the elongated flexible element 902 to the target tissue site. The elongated flexible element 902 has an arcuate configuration along its longitudinal axis when unconstrained. A generally straight control wire 908 is disposed within a lumen created by a guide member 922 along the elongated flexible element 902, thereby constraining the elongated flexible element 902 to a generally planar configuration when deployed through the lumen of the guide member. The control wire 908 can comprise a harder material and / or a greater thickness than the material and / or thickness of the remainder of the elongated flexible element 902. Although the guide member 922 having a lumen for the control wire is depicted as flat and rectangular, it should be understood that it can take on a variety of shapes, such as, for example, circular, semicircular, oval, square, mixed shapes, and the like. Furthermore, the elongated flexible member 902 can include a variety of lengths in a constrained configuration (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); and approximately 1.0 inch (approximately 25.4 mm)). To set up the system for delivery, the distal end of the elongated flexible member 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 proximally connected to the elongated flexible member. In this manner, the proximal end trails the remainder of the elongated flexible member 902 within the delivery catheter 912. The flexible arcuate portions 906 (in this embodiment, a pair of elements extending generally away from each other in a longitudinal plane in an expanded configuration) transition to a collapsed configuration while constrained within the delivery catheter 912. The tissue fastener 914 can translate distally within the delivery catheter 912, which also pushes the elongated flexible element 902 distally through the delivery catheter 912.

[0062] Alternatively, the tissue fastener 914 can be loaded into the delivery catheter 912 distally of the elongated flexible element 902. In this alternative embodiment, as the tissue fastener 914 translates distally, the tissue fastener 914 pulls the elongated flexible element 902 distally. Figure 9C As shown in the embodiment of FIG, the tissue fastener can be pushed distally to translate the elongated flexible member 902 out of the delivery catheter. Once the arcuate portion 906 exits the delivery catheter, it is no longer constrained in the collapsed configuration and can expand to an expanded configuration. Because the elongated flexible member 902 is engaged by the hook 916 of the tissue fastener 914 at the proximal loop 904, movement of the tissue fastener 914 controls movement of the elongated flexible member 902. The elongated flexible member 902 can be manipulated toward the target tissue 920.

[0063] Reference Figure 9D , Figure 9C The tissue retractor system shown in FIG can translate the elongated flexible member 902 over the target tissue after exiting the catheter by translating the tissue fastener 914 engaged at the proximal end of the flexible member 902 toward the proximal portion of the target tissue 920. The tissue fastener 914 engaged at the proximal end of the elongated flexible member 902 can then be fastened to the proximal portion of the target tissue 920. Even when attached to the elongated flexible member 902, the fastener 914 can be freely rotated to optimally position the fastener 914 to engage the target tissue 920 and position the elongated flexible member 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 member 902 hangs freely but is also proximate to a desired location on the target tissue 920 for tissue retraction (e.g., the distal portion of the target tissue).

[0064] Reference Figure 9E , Figures 9A to 9D The tissue retractor system of the present invention may introduce additional tissue fasteners 914 to engage the distal loop 904 of the elongated flexible element 902. The medical professional may introduce additional tissue fasteners 914 through the working channel of the endoscope by using the delivery catheter 912. Alternatively, the same delivery catheter may be reloaded with new fasteners 914 and / or a separate delivery catheter 912 may be used. The tissue fastener 914 may include a hook 916 to engage the distal loop 904. As an example, the delivery catheter 912 and tissue fastener 914 may be arranged along the lines of the RESOLUTION® sold by Boston Scientific Corporation. TM The invention is modeled after the lines of the clamping device. Variations of these and other devices and related components and features that may be applicable to the devices and fasteners of 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 fastener can be deployed to engage the loop 904 with the hook 916 before being locked into position in the target tissue 920. The tissue fastener 914 can be detached from the delivery catheter 912 and left 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 so that the loop 904 can be flipped to the opposite side of the tissue fastener 914 when the medical professional is positioning the elongated flexible element 902.

[0065] The control wire 908 can include a visual marker 918 that can be easily seen by a medical professional to indicate the position of the control wire 908 and the proximal portion of the elongated flexible element 902. The marker can be a chromogenic, radiopaque material disposed on the control wire 908 so that it shows up on a fluoroscope, or it can be a marker made into the control wire 908 (e.g., scored, etched, embossed, laser etched, etc.). The proximal end of the control wire 908 can be bent away from the elongated flexible element 902 so that the marker 918 is unobstructed for even better visibility. This bend in the control wire 908 also facilitates gripping the control wire 908 for removal. The marker can have an expanded profile, such as a spherical shape, compared to the rest of the control object to facilitate gripping by tools inserted through a catheter and / or scope to remove the control wire from the elongated element.

[0066] Once the second tissue fastener 914 is engaged to the distal ring 904, the tissue fastener 914 can be manipulated (e.g., rotated, flipped, etc.) to position the elongated flexible element 902 along the target tissue 920 as desired. Once the elongated flexible element 902 is in place, additional tissue fasteners can engage a second portion (e.g., the distal portion) of the target tissue 920, thereby securing the elongated flexible element 902 to the target tissue. The delivery catheter 912 can then release the second tissue fastener 914. Prior to resecting the target tissue, the medical professional can convert the elongated flexible element 902 to its arcuate configuration along the longitudinal axis. This can allow for partial tissue retraction during the resection process. Alternatively, the elongated flexible element 902 can remain in its generally planar configuration before and / or during resection of the target tissue. In order to convert the elongated flexible element 902 to the arcuate configuration, a grasping device can be introduced to the location of the target tissue 920. The grasping device can be manipulated toward the marking 918 on the curved portion of the control wire 908. With reference to Figure 9F , the control wire 908 can be grasped and pulled out of the guide member 922. In the absence of the control wire 908, the elongated flexible element 902 can transition from a generally planar configuration to an arcuate configuration along its longitudinal axis, thereby inducing a retraction force on the target tissue 920.

[0067] Reference Figure 9G , showing Figures 9A to 9FA system is provided in which the control wire 908 of the elongated flexible element 902 is removed, causing the elongated flexible element 902 to be in an arcuate configuration. In this configuration, the elongated flexible element 902 experiences a retractive force on each tissue fastener 914 and, therefore, on the target tissue 920. A resection device 924 can be introduced through the working channel of the endoscope 910 to resect a perimeter surrounding the target tissue 920. This resection of the target tissue 920 releases the target tissue 920 from surrounding tissue, allowing the target tissue 920 to succumb to the retractive force of the elongated flexible element 902 in the arcuate configuration. While the distal and proximal ends of the target tissue 920 are shown as being elevated by the fasteners 914 and loops 904, additional arms may extend from the elongated flexible element 902 in a direction extending across the target tissue 920 (e.g., orthogonal to the elongated flexible element) and include loops 904 that can be engaged by hooks 916 on the tissue fasteners 914. The arcuate portions 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 be retracted from the surrounding tissue, the arcuate portions 906 can provide additional surface area and resistance to the side portions of the target tissue 920 to retract and collapse the elongated flexible element 902. Complete resection around the perimeter of the target tissue 920 disconnects it from the surrounding tissue, which allows the elongated flexible element 902 to completely elevate 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 for passage through the gastrointestinal tract.

[0068] In the first generally planar or flat configuration of any embodiment, the body of the elongated flexible element may have a portion or all of the body positioned to contact a tissue surface. In one embodiment, the elongated flexible element may include a width and a thickness, wherein the width exceeds the thickness such that the elongated flexible element resists a tendency to roll or twist during a resection procedure. For example, the elongated flexible element may 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 a thickness (e.g., about 0.040 inches (about 1.016 mm); about 0.035 inches (about 0.889 mm); about 0.030 inches (about 0.76 2 mm); about 0.025 inches (about 0.635 mm); about 0.020 inches (about 0.508 mm). In some cases, the width can be about twice as wide as the thickness. The elongated 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 will be appreciated that the "force" stored in such material when in the constrained configuration allows the elongated flexible element to apply and maintain an upward lifting / retraction pressure against the tissue in which it is embedded. The natural tendency of the elongated flexible element to move (i.e., return) from the flat or planar shape of the first configuration to the arcuate (e.g., rounded or hemispherical) shape of the second configuration allows the resected portion of the target tissue to be lifted or elevated above the resection plane, allowing unresected target tissue to be more easily visualized and more effectively resected. The shape of the second configuration can be controlled during manufacture of the elongated flexible element to impart or set a desired memory of the elongated flexible element material when in a relaxed, unconstrained position.

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

[0071] Devices according to the described embodiments and according to other embodiments of the invention (including other accessories) can be used alone or in a system or kit or as part of a method or surgical procedure in cavities, chambers, tracts, vessels, organs, etc. of the body.

[0072] For those skilled in the art, in addition to the various embodiments described herein, variations, modifications and other embodiments of the present invention are also possible. Therefore, the present invention is not limited by the above illustrative description, but is defined by the claims.

Claims

1. A tissue retraction system comprising: an elongated flexible member having a first end and a second end and configured to transition between a first configuration when constrained and a second configuration when unconstrained; and a tissue fastener pivotally coupled to the first end of the elongated flexible element; Wherein the first end and the second end of the elongated flexible element are configured to be secured to a target tissue site.

2. The tissue retraction system of claim 1, wherein the tissue fastener is maneuverable relative to the elongate flexible member while still engaged with the elongate flexible member.

3. The tissue retraction system of claim 2, wherein the tissue fastener is capable of rotating or flipping relative to the elongated flexible element while still engaged with the elongated flexible element.

4. The tissue retraction system of claim 1, wherein the tissue fastener comprises a pair of jaws movable relative to each other, wherein one jaw is coupled to the first end of the elongated flexible element.

5. The tissue retraction system of claim 4, wherein the one jaw of the tissue fastener comprises a hook that engages the flexible elongated element.

6. The tissue retraction system of claim 5, wherein the elongated flexible element includes a loop that engages the hook on the one jaw of the tissue fastener.

7. The tissue retraction system of claim 1, wherein the elongated flexible element comprises at least one loop engageable by the tissue fastener.

8. The tissue retraction system of claim 5, wherein the elongated flexible element comprises a loop at each end thereof.

9. The tissue retraction system of claim 5, wherein the elongated flexible element comprises a loop at one end thereof and a pre-attached tissue fastener at the other end thereof.

10. The tissue retraction system of claim 1, wherein the first configuration is an elongated generally planar configuration.

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