Tissue retraction device

Abstract

To provide a tissue retraction device for assisting dissection of target tissue.SOLUTION: The present disclosure relates to a field of tissue dissection. Specifically, the present disclosure relates to medical devices which lift and retract tissue during a dissection procedure to improve visualization of the target tissue and mitigate obstruction of dissection tools. In particular, the present disclosure relates to a tissue retraction device which moves from a constrained to relaxed configuration to immobilize and retract a dissected portion of target tissue during a dissection procedure.SELECTED DRAWING: Figure 1B

Description

[Technical field]

[0001] The present invention relates to the field of tissue resection, and more particularly to a medical device that lifts and retracts tissue during a resection procedure to improve visualization of the target tissue and to avoid obstruction of the resection instrument, and more particularly to a tissue retraction device that moves from a restrained position to a relaxed position to immobilize and retract the resected portion of the target tissue during a resection procedure. [Background technology]

[0002] Surgical resection of lesions from within narrow body passageways, such as the digestive system, can be inefficient and time consuming due to the difficulty in visualizing the target tissue during the resection procedure. This problem is exacerbated during surgery when partially resected target tissue blocks the work site, further reducing visibility and interfering with the resection instruments. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-321482 A Summary of the Invention

[0004] In some aspects, the present invention relates to a tissue retraction device for immobilizing and retracting targeted tissue during a resection procedure to improve tissue visibility and manipulation. In one aspect, the invention relates to a tissue retraction device comprising an elongate flexible element having a proximal end configured to engage a first target tissue portion, a distal end configured to engage a second target tissue portion, and at least one guide member secured to the elongate flexible element, the at least one guide member defining a lumen extending therethrough, the elongate flexible element being movable between a first position (constrained, restrained, contained, or delivery position) and a second position (relaxed, free, or deployed position).

[0005] In another aspect, the invention relates to a tissue retraction device comprising an elongate flexible element having a proximal end configured to engage a first target tissue portion, a distal end configured to engage a second target tissue portion, and at least one guide member secured to the elongate flexible element, the at least one guide member defining a lumen extending therethrough and including a control wire slidably received within the lumen of the at least one guide member, the elongate flexible element moving between a first position (restricted, restrained, contained, or delivery position) when the control wire is disposed within the cavity of the at least one guide member, and a second position (relaxed, free, or deployed position) when the control wire is not disposed within the lumen of the at least one guide member. The at least one guide member comprises a plurality of guide members secured along a length of the elongate flexible element. An end of the at least one guide member includes a cap. The elongate flexible element is substantially flat in the first position. The elongate flexible element is curved along its longitudinal axis in the second position. The elongate flexible element may comprise a woven mesh. Additionally or alternatively, the elongate flexible element comprises a plurality of parallel elements. The parallel elements may be secured relative to one another by at least one or more guide members. A portion of the parallel elements are curved outwardly from the longitudinal axis of the elongate flexible element. The control wire passes between the parallel elements when disposed within the lumen of the at least one guide member. The proximal and distal ends of the elongate flexible element comprise one or more tissue anchors, such as tines, forks, hooks, fingers, barbs, loops, and / or clips. Additionally or alternatively, one or more stabilizers, such as hooks and / or barbs, are secured to the elongate flexible element. The elongated flexible elements are formed from polymers such as, but not limited to, acrylate-based polymers, polyurethane-based polymers, polynorbornene-based polymers, polylactide-based polymers, etc. Additionally or alternatively, the elongated flexible elements are formed from metals or metal alloys such as, but not limited to, platinum, tungsten, titanium, stainless steel, nickel, nickel-titanium alloys, and alloys of the above or other metals.

[0006] In another aspect, the present application relates to a system comprising a delivery catheter and an elongate flexible element slidably received within a lumen of the delivery catheter. The elongate flexible element has a proximal end configured to engage a first target tissue portion, a distal end configured to engage a second target tissue portion, at least one guide member secured to the elongate flexible element, the at least one guide member defining a lumen extending therethrough, and a control member slidably received within the lumen of the at least one guide member. The elongate flexible element moves between a first position (constrained, restricted, contained, or delivery position) when the control element is disposed within the lumen of the at least one guide member, and a second position (relaxed, free, or deployed position) when not disposed within the lumen of the at least one guide member. A proximal end of the control wire extends beyond the end of the delivery catheter. The delivery catheter is slidably received within a working channel of an endoscope. Additionally or alternatively, at least one guide member is fixed along the length of the elongate flexible element.

[0007] In yet another aspect, the invention relates to a method comprising advancing a delivery catheter through a working channel of an endoscope to a position adjacent a target tissue such that a distal end of the delivery catheter is over a first portion of the target tissue, the working channel of the delivery catheter comprising an elongate flexible element having a proximal end configured to engage a first target tissue portion and a distal end configured to engage a second target tissue portion, the elongate flexible element comprising at least one guide member secured to the elongate flexible element, the at least one guide member defining a lumen therethrough and a control wire slidably received within the lumen of the at least one guide member, the at least one guide member being configured to extend through the lumen of the at least one guide member such that the control wire is slidably received within the lumen of the at least one guide member. and a second position when the control wire is not disposed within the lumen of the at least one guide member, advancing the control wire distally such that the elongated flexible element engages a first portion of the target tissue beyond the distal end of the delivery catheter, retracting the delivery catheter proximally such that the proximal end of the elongated flexible element moves beyond the distal end of the delivery catheter, moving the distal end of the delivery catheter relative to 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, and retracting the control wire proximally such that the control wire is removed from within the lumen of the at least one guide member. The method may further include advancing a tissue removal element, such as a resection element, through a working channel of the endoscope and resecting circumferentially around the target tissue as the elongated flexible element moves from the first position to the second position.

[0008] Non-limiting examples of the present invention are described by way of example with reference to the accompanying drawings, which are schematic diagrams and are not intended to be drawn to scale. In the drawings, identical or substantially identical components shown are generally designated by a single numeral. For simplicity, not all components are necessarily numbered in the drawings, and not all components of each embodiment of the present invention are necessarily shown, unless necessary for a person skilled in the art to understand the invention. [Brief description of the drawings]

[0009] [Figure 1A] 1 illustrates a tissue retraction device in a restrained position according to an embodiment of the present invention. [Figure 1B] 1 illustrates a tissue retraction device in a relaxed curved position according to an embodiment of the present invention. [Figure 2A] 13A-13C illustrate tissue anchor elements that may be positioned on either end of a tissue retraction device according to an embodiment of the present invention. [Figure 2B] 13A-13C illustrate tissue anchor elements that may be positioned on either end of a tissue retraction device according to an embodiment of the present invention. [Figure 2C] 13A-13C illustrate tissue anchor elements that may be positioned on either end of a tissue retraction device according to an embodiment of the present invention. [Figure 2D] 13A-13C illustrate tissue anchor elements that may be positioned on either end of a tissue retraction device according to an embodiment of the present invention. [Diagram 3] 13A-13C show tissue stabilizers disposed on the underside of a tissue retraction device according to an embodiment of the present invention. [Figure 4A] 1 illustrates a portion of a parallel tissue retraction device according to an embodiment of the present invention. [Figure 4B] 1 illustrates a portion of a tissue retraction device in a curved position according to an embodiment of the present invention. [Diagram 5] 1B illustrates the tissue retraction device of FIG. 1A positioned within a lumen of a delivery system according to an embodiment of the present invention. [Figure 6A] 13A-13D illustrate a method of placing a tissue retraction device on a target tissue according to an embodiment of the present invention. [Figure 6B] 13A-13D illustrate a method of placing a tissue retraction device on a target tissue according to an embodiment of the present invention. [Figure 6C] 13A-13D illustrate a method of placing a tissue retraction device on a target tissue according to an embodiment of the present invention. [Figure 6D] 13A-13D illustrate a method of placing a tissue retraction device on a target tissue according to an embodiment of the present invention. [Figure 7A] 1A-1C illustrate cutting of targeted tissue using a tissue retraction device according to an embodiment of the present invention. [Figure 7B]1A-1C illustrate cutting of targeted tissue using a tissue retraction device according to an embodiment of the present invention. [Figure 7C] 1A-1C illustrate cutting of targeted tissue using a tissue retraction device according to an embodiment of the present invention. [Figure 8A] 13 illustrates a tissue retraction device in a constrained flat position in accordance with another embodiment of the present invention. [Figure 8B] 1 illustrates a tissue retraction device in a relaxed curved position according to an embodiment of the present invention. [Figure 9] FIG. 1 illustrates two tissue retraction devices positioned along opposing planes of a target tissue according to an embodiment of the present invention. [Figure 10A] 13 illustrates a tissue retraction device in a restraining position according to another embodiment of the present invention. [Figure 10B] 13 illustrates a tissue retraction device in a relaxed position according to another embodiment of the present invention. [Figure 11A] 13 illustrates a tissue retraction device in a restraining position according to another embodiment of the present invention. [Figure 11B] 13 illustrates a tissue retraction device in a relaxed position according to another embodiment of the present invention. [Figure 11C] 13 illustrates a tissue retraction device in a delivery position according to another embodiment of the present invention. [Figure 12A] 13 illustrates a tissue retraction device in a restraining position according to another embodiment of the present invention. [Figure 12B] 13 illustrates a tissue retraction device in a relaxed position according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] It should be noted that the drawings are intended to describe general or exemplary embodiments of the invention. Therefore, the drawings should not be understood as limiting the scope of the invention. The invention is described in more detail below with reference to the accompanying drawings.

[0011] Before describing the present invention in further detail, it should be understood that the present invention is not limited to the specific embodiments described, as various embodiments are possible. The terms used in this specification are for the purpose of describing the specific embodiments only, and are not intended to be limiting beyond the scope of the appended claims. Unless otherwise defined, all technical terms used herein have the same meaning as would be commonly understood by one of ordinary skill in the art to which the present invention pertains. Finally, although the embodiments of the present application are described with specific reference to medical devices and systems for resecting tissue of the digestive system, it should be understood that the medical devices may also be used to resect tissue of the abdominal cavity, gastrointestinal system, thoracic cavity, etc. Additionally, various medical procedures, such as endoscopic submucosal dissection (ESD), peroral endoscopic myotomy (POEM), cholecystectomy, video-assisted thoracic surgery (VATS), etc., may benefit from the medical devices disclosed herein.

[0012] As used herein, the term "distal" refers to the end of the device that is furthest from the medical practitioner when inserted into a patient's body, and the term "proximal" refers to the end of the medical device that is closest to the medical practitioner when inserted into a patient's body.

[0013] As used herein, the term "tissue retraction" or "retraction" refers to the ability to control the position of tissue during a resection procedure. For example, "retraction" can mean immobilizing the resected portion of the target tissue and lifting it from the remaining (non-resected) portion of the target tissue to improve visualization and lift it off the resection surface, as well as applying tension to the target tissue for more precise manipulation of the resection element.

[0014] As used herein, the term "target tissue" refers to an unhealthy or diseased (cancerous, precancerous) or unwanted portion of tissue. "Target tissue" also includes tissue suspected to be unhealthy or diseased, but such tissue conditions require surgical removal to confirm the pathology with a biopsy. It should be understood that surgical removal of "target tissue" generally involves removal of healthy tissue portions surrounding the "target tissue" to ensure complete removal and minimize the possibility of residual or unremoved "target tissue" cells metastasizing to other parts of the body.

[0015] In one embodiment, the present invention provides a tissue retraction device that retracts and immobilizes a resected target tissue portion, such as to prevent occlusion or blockage of a working channel of an endoscope, thereby improving visibility and access to the target tissue during a resection procedure. As shown in FIGS. 1A-1B, in one embodiment, the tissue retraction device of the present application comprises an elongated flexible element 110 (e.g., a spine) having a proximal end 112 configured to engage a first target tissue portion, a distal end 114 configured to engage a second target tissue portion, a first surface 116 (top, or upper surface), and a second surface 118 (bottom, or lower surface). A plurality of guide members 130 are disposed along the length of the elongated flexible element 110. Although the guide members 130 in FIGS. 1A-1B are evenly spaced along the second surface 118 of the elongated flexible element 110, the guide members may be disposed on the first and / or second surfaces 116, 118 in an even or non-even pattern. Alternatively, the guide members may be tangential or flush with either the first or second surfaces 116, 118 of the elongated flexible element 110. Additionally, while the elongated flexible element 110 shown in FIGS. 1A-1B includes five guide members 130, it should be understood that the number of guide members 130 may be less than five (e.g., four or less) or more than five (e.g., six or more). Although shown as circular, the guide members may have any of a variety of shapes in cross section, such as semicircular, oval, square, rectangular, etc. The elongated flexible elements may have a variety of lengths (e.g., about 6 inches (1 inch = 2.54 centimeters), about 5 inches, about 4 inches, about 3 inches, about 2.75 inches, about 2.0 inches, about 1.5 inches, about 1.0 inches, etc.). Each guide member 130 defines a lumen 132 extending therethrough. In one embodiment, the distal most end of guide member 130 (the guide member closest to distal end 114 of elongate flexible element 110) comprises a cap 134. In one embodiment, elongate flexible element 110 is made up of parallel elements or wires 126a, 126b connected together by multiple guide members 130.The tissue retraction device may further include a control wire 140 (e.g., a holding mandrel) slidably received in a corresponding lumen 132 of each guide member 130 along the longitudinal axis of the elongate flexible element 110. With reference to FIG. 1A, when the control wire 140 is disposed within the lumen 132 of each guide member 130, the elongate flexible element 110 is held in a first position (a restricted, restrained, contained, or delivery position). With reference to FIG. 1B, when the control wire 140 is not disposed (removed) within the lumen 132 of each guide member 130, the elongate flexible element 110 moves to a second position (a relaxed, free, or deployed position).

[0016] In the first position, the elongate flexible element 110 has a flat or planar position such that substantially all of the second surface 118 is disposed against the tissue surface. In one embodiment, the elongate flexible element 110 has a width and a thickness, and the width is greater than the thickness such that the elongate flexible element 110 does not roll up or twist during the resection procedure. For example, the elongate flexible element has a width (e.g., about 0.070 inches, about 0.065 inches, about 0.060 inches, about 0.055 inches, about 0.050 inches) that is greater than the thickness (e.g., about 0.04 inches (1 inch = 2.54 centimeters), about 0.035 inches, about 0.030 inches, about 0.025 inches, about 0.020 inches), and in some cases, the width is about twice as large as the thickness. The elongated flexible element 110 may be formed from a variety of elastic biocompatible materials, including, for example, 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.

[0017] When in the constrained position, the elongated flexible element 110 can apply and hold a constant upward or retracting pressure on the embedded tissue due to the "force" stored within the material. The inherent tendency of the elongated flexible element 110 to move from a flat or planar shape in a first position to a curved (e.g., rounded or hemispherical) shape in a second position allows the resected portion of the target tissue to be lifted or elevated above the cutting surface so that the resected portion of the target tissue can be more easily visualized and more effectively resected. The shape of the second position can be controlled during operation to impart or set a desired memory to the material of the elongated flexible element in a relaxed or unconstrained position.

[0018] 2A-2D, the proximal and distal ends 112, 114 of the elongated flexible element 110 may be provided with various anchoring configurations, such as, but not limited to, wire prongs or tines (FIG. 2A), wire forks, fingers or hooks (FIG. 2B), wire ends (FIG. 2C) and / or loops, clips or barbs (FIG. 2D), etc., to prevent the elongated flexible element 110 from detaching from the tissue surface before the resection procedure is completed. Additionally or alternatively, the proximal and distal ends 112, 114 are preferably provided with sharp or pointed tips to facilitate penetration of tissue. In one embodiment, these (and other) wire anchoring elements are made of a shape memory material, such as Nitinol, and are heat set to point downward when deployed, but are constrained in a straight configuration within the delivery catheter prior to deployment. When implanted within a target tissue, the proximal and distal ends 112, 114 simultaneously drive or push the second surface 118 of the elongated flexible element 110 downward against the target tissue surface, creating an upward (e.g., lifting) and outward (e.g., longitudinal) retracting force within the target tissue.

[0019] 3, in one embodiment, one or more stabilizers 325 (e.g., hooks, barbs, etc.) are disposed along and extend outwardly from one or more guide members 330 secured to the second surface 318 of the elongated flexible element 410. Pressure applied along the second surface 318 of the elongated flexible element 310 against the target tissue may cause the stabilizers 325 to engage a portion of the target tissue between the proximal and distal ends 312, 314. The additional tissue engagement provided by the stabilizers 325 may provide additional retraction force to the target tissue and further prevent or minimize the elongated flexible element 310 from rolling over or twisting during the resection procedure.

[0020] 4A-4B, in one embodiment, the portions of parallel wires 426a, 426b between one or more guide members 430 may splay or collapse outward to provide one or more increased surface areas for additional stability (e.g., resistance to curling or kinking) following placement of elongated flexible element 410. For example, one or more portions of parallel wires 426a, 426b may be heat treated during manufacturing to provide a straight orientation when restrained (FIG. 4A) and a collapsed outward orientation upon exiting the delivery tube (FIG. 4B).

[0021] 5, in one embodiment, the invention comprises a delivery system comprised of an elongated flexible element 510 slidably disposed in a first position (constrained) within a lumen 556 of a delivery catheter 550 (e.g., an overtube, constraining sheath). A control wire 540 extends through the lumen 556 of the delivery catheter 550 such that a proximal end (not shown) of the control wire 540 extends beyond a proximal end (not shown) of the delivery catheter 550.

[0022] In FIG. 6A, in use and in an exemplary method, the endoscope 660 is advanced through the body passageway such that the distal end 664 of the endoscope 660 is disposed proximate the target tissue 72. A delivery system, such as the catheter of FIG. 5, is then advanced through the working channel 666 of the endoscope 660 such that the distal end 644 of the delivery catheter 650 is disposed over a first portion of the target tissue 72. The proximal end of the control wire is then advanced distally such that the distal end 614 of the elongated flexible element 610 moves beyond the distal end 654 of the delivery catheter 650. It should be appreciated that the cap 634 of the distal-most guide member 630 (FIG. 6B) provides a surface against which the control wire 640 exerts a distal force. The control wire 640 is advanced further distally to embed the distal end 614 of the elongated flexible element 610 within the first portion of the target tissue 72. Alternatively, the control wires secure the advanced catheter or endoscope to implant the anchor in place. In one embodiment, the distal end 614 moves from a restrained position to a deployed position upon exiting the delivery catheter 650. The deployed position provides a larger (broader) surface area for stronger engagement with the target tissue. In FIG. 6B, while a distal force is applied (maintained) on the elongated flexible element 610 by the control wires 640, the delivery catheter 650 is retracted proximally to move the proximal end 612 of the elongated flexible element 610 past the distal end 654 of the delivery catheter 650. In FIG. 6C, the distal end 654 of the delivery catheter 650 is advanced to generate or apply a distal force to the proximal end 612 of the elongated flexible element 610 to embed the proximal end 612 within a second portion of the target tissue 72. The distal force exerted by the distal end 654 of the delivery catheter 650 against the proximal end 612 causes the elongate flexible element 610 to curve or bend inwardly before (or during) implantation of the proximal end 612 within the second portion of the target tissue 72. When the distal force exerted by the distal end 654 of the delivery catheter 650 is removed, the elongate flexible element 610 returns to an unbent position, allowing the proximal and distal ends 612, 614 to be further pushed into and engaged with the first and second portions of the target tissue 72, respectively.Alternatively, application of sufficient distal pressure to the control wires may cause the elongated flexible elements to bend sufficiently to implant the anchors without engaging the elongated flexible elements with the distal end of the delivery catheter. Additionally or alternatively, the anchors may self-position or implant with little or no distal pressure. In FIG. 6D, the control wires 640 are then retracted proximally from within the lumens 632 of each guide member 630 and removed. With the control wires 640 removed, the elongated flexible elements 610 exert an upward and outward force on the proximal and distal ends 612, 614 as they are further secured to the target tissue 72 by their inherent tendency to move from their first position to their second position. Pressure is also generated to simultaneously drive or push the second surface 618 of the elongated flexible elements 610 against the surface of the target tissue 72. It should be appreciated that in some surgical procedures it may be desirable to implant one or both of the proximal and distal ends 612, 614 within healthy tissue (e.g., non-diseased) outside or beyond the periphery of the target tissue to minimize the possibility of leaving behind cancerous cells that may lead to metastases. In such cases, tissue is retracted only from the side of the elongated flexible element that has an anchor embedded within the resected tissue.

[0023] 7A-7C, the resection element 768 is then advanced through the working channel 766 of the endoscope 760 to resect the target tissue 72 from the surrounding healthy tissue 70. Once the target tissue 72 has been resected, the portion of the elongated flexible element 710 secured to the diseased tissue is moved from a first position to a second position to lift and pull the diseased target tissue 72 away from the resection element 768 and the endoscopic camera 769. Once the target tissue has been completely resected, the elongated flexible element 710 and the target tissue 72 secured thereto may be removed through the working channel 766 of the endoscope 760 using a suitable grasping element (not shown) for biopsy. Alternatively, the elongated flexible element 710 and the target tissue 72 secured thereto may be left in place within a body passageway for removal via the body's natural passageway. Importantly, the elongated flexible element 710 does not occupy the working channel 766 of the endoscope 760 during the resection procedure, allowing medical personnel to introduce and manipulate additional medical instruments required for a given medical procedure.

[0024] 8A-8B, in one embodiment, the tissue retraction device of the present invention comprises an elongated flexible element 810 comprising a mesh-like structure formed of polymers, metals, or alloys in various woven or interwoven configurations. Proximal and distal ends 812, 814 of the elongated flexible element 810 may comprise a plurality of free wire ends 824 (e.g., wire tips) configured to engage first and second target tissue portions in a Velcro-like manner. In one embodiment, a surface of the elongated flexible element 810 may comprise one or more guide members that receive control wires (not shown). As described above, the control wires may hold the elongated flexible element 810 in a first position (constrained) when disposed within the central lumen (FIG. 8A) and return the elongated flexible element to a second position (relaxed) when not disposed within the central lumen (FIG. 8B). The elongated flexible element 810 may be positioned in and on the target tissue using a delivery catheter and endoscope as described above.

[0025] 9, in one embodiment, one or more elongated flexible elements 910a, 910b are positioned at the target tissue 72 to provide multiple tissue retraction planes. For example, a first elongated flexible element 910a is positioned along a first plane of the target tissue 72, and a second elongated flexible element 910b is positioned orthogonally above the first elongated flexible element 910a along a second plane of the target tissue 72. By providing multiple retraction planes using multiple elongated flexible elements, the tissue retraction forces required to safely and efficiently resect large and / or irregularly shaped target tissues or resect tissue in and around delicate anatomical structures may be provided.

[0026] 10A, in one embodiment, a tissue retraction device of the present invention includes an elongated flexible element 1010 as described above, and further includes first and second arms 1028a, 1028b (e.g., strips, petals, legs, etc.) extending radially outward from a central portion 1013 of the elongated flexible element 1010. An end 1029a of the first arm 1028a engages a third target tissue portion, and an end 1029b of the second arm 1028b engages a fourth target tissue portion. A plurality of guide members 1030 are disposed on a first surface 1016 (e.g., a top surface) of the first and second arms 1028a, 1028b. Each guide member 1030 defines a lumen 1032 extending therethrough. In one embodiment, the distal most ends of the guide members 1030 of the first and second arms 1028a, 1028b (the guide members closest to the ends 1029a, 1029b) include caps 1034 to provide a surface against which the control wires exert distal force. Finally, the tissue retraction device further includes first and second control wires 1040a, 1040b, respectively, slidably received in lumens 1032 of each guide member 1030 disposed along the first surface 1016 of the first and second arms 1028a, 1028b. For example, the first control wire 1040a extends along the first surface 1016 of the proximal portion 1017 of the elongate flexible element 1010 and bends at a central portion 1013 at an angle of approximately 90 degrees to be slidably received in the lumen 1032 of the guide member 1030 on the first arm 1028a. The second control wire 1040b extends parallel to the first control wire 1040a along the first surface 1016 of the proximal portion 1017 of the elongate flexible element 1010, bends at a 90 degree angle at the central portion 1013, and is slidably received in the lumen 1032 of the guide member 1030 on the second arm 1028b. Although not shown, an additional control wire (a third control wire) may be disposed along the second surface 1018 (e.g., the underside) of the elongate flexible element 1010, as shown in FIGS. 1A-1B. When the first and second control wires 1040a, 1040b are disposed within the lumens 1032 of the respective guide members 1030, the first and second arms 1028a, 1028b are held in a first position (constrained).10B, the first and second arms 1028a, 1028b move to a second position (relaxed) when the first and second control wires 1040a, 1040b are not disposed (removed) within the lumens 1032 of each guide member 1030. When in the constrained position, the "force" stored within the material may cause the elongated flexible element 1010 to exert and hold a constant pressure to lift or retract upward along multiple planes of the implanted target tissue.

[0027] The tissue retraction device shown in FIG. 10B may be slidably disposed within the lumen of a delivery catheter as described above. In one embodiment, the elongated flexible element 1010 portion of the tissue retraction device is positioned on the target tissue according to the process described above. The first and second control wires 1040a, 1040b are then advanced distally such that the first and second arms 1028a, 1028b are in an outwardly planar position (FIG. 10A) such that the ends 1029a, 1029b engage the third and fourth tissue portions, respectively. The arms of the elongated flexible element may be formed in a variety of shapes, and the ends 1029a, 1029b of each arm may include any tissue anchor configuration, for example as shown in FIGS. 2A-2D.

[0028] 11A, in another embodiment, the tissue retraction device of the present invention further comprises first and second arms 1128a, 1128b extending radially from a distal portion 1115 of the elongated flexible element 1110, and third and fourth arms 1128c, 1128d extending radially from a proximal portion 1117 of the elongated flexible element 1110, as shown in FIG 1A. An end 1129a of the first arm 1128a may engage a third target tissue portion, an end 1129b of the second arm 1128b may engage a fourth target tissue portion, an end 1129c of the third arm 1128c may engage a fifth target tissue portion, and an end 1129d of the fourth arm 1128d may engage a sixth target tissue portion. A plurality of guide members 1030 may be disposed along the first surface 1118 (top surface) of the first, second, third, and fourth arms 1128a-d. Each guide member 1130 defines a lumen extending therethrough. In one embodiment, the distal-most guide member 1130 (the guide member closest to the ends 1129a-d) of each of the first, second, third, and fourth arms 1028a-d includes an end cap to provide a surface against which the control wires exert distal force. Finally, the tissue retraction device may further include first, second, and third control wires 1140a, 1140b, and 1140c, respectively, slidably received in the lumen of each guide member 1130 disposed along the first surface 1118 of the first, second, third, and fourth arms 1128a-d. For example, the first control wire 1140a may extend along the first surface 1118 of the elongate flexible element 1110 and include a fork or split that is slidably received in a lumen of the guide member 1130 on the first and second arms 1128a, 1128b. Alternatively, the first and second arms 1128a, 1128b of the elongate flexible element 1110 may include separate or different control wires (not shown) that may be positioned separately. The first control wire 1140b may extend parallel to a portion of the first control wire 1140a and bend at an angle of 90 degrees or more at the proximal portion 1117 of the elongate flexible element 1110 to be slidably received in a lumen of the guide member 1130 on the third arm 1128c.The third control wire 1140c runs parallel to a portion of the first control wire 1140a, bends at an angle of 90 degrees or more at the proximal portion 1117 of the elongate flexible element 1110, and is slidably received in a lumen of the guide member 1130 on the fourth arm 1128d. Although not shown, an additional control wire (a fourth control wire) may be disposed along a second surface (lower surface) of the elongate flexible element 1110, as shown, for example, in FIGS. 1A-1B.

[0029] When the first, second, and third control wires 1140a-c are disposed within the lumens of the respective guide members 1130, the first, second, third, and fourth arms 1128a-d are held in a first position (constrained). In FIG. 11B, when the first, second, and third adjustment wires 1140a-c (not shown) are not disposed within the respective guide members 1130 (removed), the first, second, third, and fourth arms 1128a-d move to a second position (relaxed). Additionally or alternatively, the distal and proximal arms along the long axis may be folded toward the second position when unconstrained, as may the other arms. 11C, in one embodiment, the first, second, third, and fourth arms 1128a-d are formed of a material that is sufficiently flexible or deformable so that when constrained within the lumen of a delivery catheter, they may contract inwardly along the elongate flexible element. When in the constrained position, the "force" stored within the material may cause the elongate flexible element 1110 to exert and maintain a constant uplift or retract pressure along multiple planes of the implanted target tissue.

[0030] The tissue retraction device shown in FIG. 11C may be slidably disposed within the lumen of a delivery catheter as described above. In one embodiment, a portion of the elongated flexible element 1110 of the tissue retraction device is positioned over the target tissue site according to the steps described above. The first, second, and third adjustment wires (not shown) are then advanced distally to urge the ends 1129a-d outwardly into the deployed position (FIG. 11A) such that they engage the third, fourth, fifth, and sixth tissues, respectively. The ends 1129a-d of each arm may comprise any tissue anchor configuration, such as those shown in FIGS. 2A-2D.

[0031] 12A-12B, in one embodiment, the tissue retraction device of the present invention may comprise a sheet 1210 of shape memory material that moves between a first position (constrained) (FIG. 12B) and a second position (relaxed, rolled or contracted) (FIG. 12A). A plurality of tissue anchors 1224 may be disposed about the periphery 1210a of the sheet 1210. While the tissue anchors 1224 in FIGS. 12A-12B are substantially equally spaced about the periphery 1210a of the sheet 1210, it should be understood that the tissue anchors may be disposed about the periphery 1210a in an even or uneven pattern. The "force" stored within the shape memory material may provide and hold a constant lifting or retracting pressure along multiple planes of the implanted target tissue. As shown in FIG. 12A, the sheet 1210 may be rolled up in the second relaxed, cylindrically shaped position and slidably disposed within the lumen of a delivery catheter (not shown) for delivery in a restrained state. The sheet 1210 is advanced distally beyond the distal end of the delivery catheter and deployed to the first constrained position of FIG. 12B, allowing the tissue anchors 1224 to engage portions of the target tissue. Additionally or alternatively, a medical device (biopsy forceps) is advanced through the delivery catheter to precisely position the sheet 1210 and exert sufficient pressure to engage at least some of the tissue anchors 1224 within the target tissue. Once the sheet 1210 is secured to the target tissue in the first position (FIG. 12B), the central portion of the sheet 1210 can be stimulated by contacting (pushing, tapping, hitting) the medical device to return the sheet 1210 to the second shape memory position (FIG. 12A) and create upward lifting or retracting pressure against the target tissue. It is understood that the tissue retraction devices described herein can include at least one arm and tissue anchor of any number, shape, size, and orientation.

[0032] All of the devices and / or methods disclosed and claimed herein can be made and practiced without undue experimentation with respect to the present invention. Although the devices and methods of the present invention are described in terms of preferred embodiments, those skilled in the art will recognize that they can be adapted to the devices and / or methods, and the steps or sequence of steps described herein, without departing from the concept, spirit and scope of the invention. Accordingly, all similar substitutes and modifications that may occur to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims.

[0033] (Additional Note) (Appendix 1) A delivery catheter; an elongate flexible element slidably disposed within the lumen of the delivery catheter; the elongated flexible element comprises a proximal end, a distal end, and an intermediate portion extending between the proximal end and the distal end, the proximal end and the distal end of the elongated flexible element each comprising one or more tissue anchors and configured to be implanted into a first portion of a target tissue and a second portion of a target tissue to apply a lifting force to the target tissue to separate the target tissue from adjacent tissue; The system for assisting in the excision of target tissue, wherein the elongated flexible element is configured to be movable between a first position in which the proximal end and the distal end are flat with respect to the intermediate portion and a second position in which the proximal end and the distal end are curved with respect to the intermediate portion, and when moved from the first position to the second position, the target tissue moves in a direction away from adjacent tissue.

[0034] (Appendix 2) 2. The system of claim 1, wherein the one or more tissue anchors of the elongated flexible element prevent the elongated flexible element from detaching from the target tissue surface when implanted in the target tissue.

[0035] (Appendix 3) 3. The system of claim 1 or 2, wherein the elongated flexible element is formed from an elastic biocompatible material and is movable from the first flat position to the second curved position due to the elastic force of the elastic biocompatible material.

[0036] (Appendix 4) 4. The system of any one of claims 1 to 3, wherein the elongated flexible element includes at least one guide member, the at least one guide member defining a lumen extending therethrough.

[0037] (Appendix 5) 5. The system of claim 4, wherein the at least one guide member comprises a plurality of guide members attached along a length of the elongated flexible element.

[0038] (Appendix 6) 6. The system of claim 4 or 5, further comprising a control wire slidably received within the lumen of the at least one guide member.

[0039] (Appendix 7) 7. The system of claim 6, wherein the elongated flexible element is configured to be maintained in the first flat position when the control wire is disposed within the lumen of the at least one guide member and to move from the first flat position to the second curved position when the control wire is not disposed within the lumen of the at least one guide member.

[0040] (Appendix 8) 8. The system of any one of claims 4-7, further comprising at least one stabilizer disposed along the at least one guide member attached to the elongated flexible element and configured to extend outwardly from the at least one guide member to engage the target tissue.

[0041] (Appendix 9) 9. The system of claim 8, wherein the stabilizer comprises one or more tissue engaging elements selected from hooks or barbs.

[0042] (Appendix 10) 10. The system of any one of claims 1 to 9, wherein the elongated flexible element comprises a pair of parallel wire elements.

[0043] (Appendix 11) 11. The system of claim 10, wherein the elongated flexible element comprises at least one guide member, and the pair of parallel wire elements are connected to each other by the at least one guide member.

[0044] (Appendix 12) 11. The system of claim 10, wherein the elongated flexible element includes a plurality of guide members attached along the length of the elongated flexible element, the pair of parallel wire elements being connected to one another by the plurality of guide members and configured to curve outwardly between the plurality of guide members in a direction away from the longitudinal axis of the elongated flexible element.

[0045] (Appendix 13) 13. The system of any one of claims 1-12, wherein the elongated flexible element further comprises one or more arms extending radially outward from a side of the elongated flexible element, the one or more arms configured to engage the target tissue and apply a lifting force to the target tissue to peel the target tissue from adjacent tissue.

[0046] (Appendix 14) 14. The system of any one of claims 1-13, wherein the delivery catheter is slidably disposed within a working channel of an endoscope.

[0047] (Appendix 15) A delivery catheter; an elongate flexible element slidably disposed within the lumen of the delivery catheter; the elongated flexible element comprises proximal and distal ends configured to engage first and second portions of a target tissue and apply a lifting force to the target tissue to separate the target tissue from adjacent tissue; A system for assisting in the resection of target tissue, wherein the elongated flexible element is configured to be movable between a first, flat position when constrained and a second, curved position when unconstrained, and when moved from the first position to the second position, the target tissue moves in a direction away from adjacent tissue.

Claims

1. 1. A tissue retraction device comprising an elongate flexible element, the elongate flexible element comprising: a proximal end configured to engage a first target tissue site; a distal end opposite the proximal end and configured to engage a second target tissue site; and at least two wires extending between the proximal end and the distal end; Equipped with A tissue retraction device, wherein the elongate flexible elements are movable between a first position in which the wires are parallel to one another and a second position in which the wires are spaced outwardly from one another.

2. The tissue retraction device of claim 1 , further comprising at least one guide member attached to said elongated flexible element, said at least one guide member defining a lumen extending therethrough.

3. The tissue retraction device of claim 2 , further comprising a control wire slidably received within the lumen of the at least one guide member.

4. The tissue retraction device of claim 3 , wherein the elongate flexible element is movable between the first and second positions in response to positioning the control wire relative to the lumen of the at least one guide member.

5. The tissue retraction device of any one of claims 1 to 4, wherein the elongated flexible element is movable between the first and second positions in response to positioning the elongated flexible element relative to a catheter.

6. The tissue retraction device of any one of claims 1 to 5, wherein the wire is preset to the second position such that the wire assumes the second position when the elongated flexible element is released.

7. The tissue retraction device of any one of claims 1 to 6, wherein the wires form a plane generally parallel to the target tissue when spaced apart in the second position.

8. 8. The tissue retraction device of claim 1, further comprising a first tissue anchor provided at the proximal end of the elongated flexible element and a second tissue anchor provided at the distal end of the elongated flexible element.

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