WO2018223237A1

WO2018223237A1 - Tissue displacement device and method

Info

Publication number: WO2018223237A1
Application number: PCT/CA2018/050684
Authority: WO
Inventors: Jean-Luc Pageard; André TREMBLAY; Boby CHU; Daniel MOK; Benoit Thibault
Original assignee: Pageard Jean Luc; Tremblay Andre; Chu Boby; Mok Daniel; Benoit Thibault
Priority date: 2017-06-07
Filing date: 2018-06-07
Publication date: 2018-12-13

Abstract

A tissue displacement device is provided for displacing tissue of a subject, the tissue displacement device comprising a flexible tube having a wall defining a lumen extending therethrough. The flexible tube has a proximal handle portion, a distal tip, and a displacement portion between the proximal handle portion and the distal tip, for displacement of a tissue structure with which the displacement portion is in contact, in use. Also provided is at least one inflatable membrane fluidly connected to the lumen of the flexible tube at the displacement portion, the inflatable membrane being deployable between an uninflated state and an inflatable state. One or both of the inflatable membrane and the wall of the flexible tube at the displacement portion are arranged to move the displacement portion from a first configuration to a second configuration in which a bending along a longitudinal axis of the displacement portion can impart a displacement force to the tissue structure.

Description

TISSUE DISPLACEMENT DEVICE AND METHOD

FIELD OF THE DISCLOSURE

[0001] The present disclosure relates to devices and methods for displacing tissues, specifically but not exclusively to devices and methods for displacing esophageal tissue. BACKGROUND OF THE DISCLOSURE

[0002] Certain treatments of tissue involve extremes of temperature or other conditions, such as intense heat, which can put neighbouring tissues at risk of damage.

[0003] One such tissue treatment is thermal ablation. Left atrial thermal ablation is a procedure performed on the left atrium for treatment of atrial fibrillation. Due to the proximity of the esophagus to the atrium, a complication linked to this procedure is thermal damage to the esophagus resulting in esophageal fistula. Esophageal fistula is associated with a high risk of morbidity or death (more than 50%). Furthermore, a medical practitioner may compromise the extent and duration of the atrial ablation due to a fear of inducing esophageal fistula, thereby possibly reducing the potential usefulness of the atrial ablation procedure. [0004] Medical practitioners have attempted to physically displace the esophagus away from the left atrium during thermal ablation to avoid or minimize thermal damage to the esophagus, with limited success.

[0005] Straight probes, such as thermometers, have been inserted into the esophagus and physical manipulation of the esophagus away from the left atrium attempted by pushing a handle end of the probe. Curved probes have also been used, such as those described in US 7621908, US8506589 and US 8529443.

[0006] However, these known methods have a number of drawbacks, such as localized bleeding in the esophagus at or near the point of contact of the probe and the esophagus, ability to precisely control the extent of displacement, and problems imaging the extent of deflection of the esophagus in order to assess whether it is sufficiently deflected so that the atrial ablation can proceed safely.

[0007] Therefore, there is a need for a device and method for tissue deflection which overcomes or reduces at least some of the above-described problems. SUMMARY OF THE DISCLOSURE

[0008] It is an object of the present disclosure to ameliorate at least some of the inconveniences present in the prior art.

[0009] From one aspect, there is provided a tissue displacement device for displacing tissue of a subject, the tissue displacement device comprising: a flexible tube having a wall defining a lumen extending therethrough, the flexible tube having a proximal handle portion, a distal tip, and a displacement portion between the proximal handle portion and the distal tip, for displacement of a tissue structure with which the displacement portion is in contact, in use; at least one inflatable membrane fluidly connected to the lumen of the flexible tube at the displacement portion, the inflatable membrane being deployable between an uninflated state and an inflatable state; wherein one or both of the inflatable membrane and the flexible tube at the displacement portion are arranged to move the displacement portion from a first configuration to a second configuration in which a bending along a longitudinal axis of the displacement portion can impart a displacement force to the tissue structure.

[0010] From another aspect there is provided a tissue displacement device for displacing tissue of a subject, the tissue displacement device comprising: a flexible tube having a wall defining a lumen extending therethrough, the flexible tube having a proximal handle portion, a distal tip, and a displacement portion between the proximal handle portion and the distal tip, for displacement of a tissue structure with which the displacement portion is in contact, in use; at least one inflatable membrane fluidly connected to the lumen of the flexible tube at the displacement portion, the inflatable membrane being deployable between an uninflated state, in which the displacement portion has a first configuration, and an inflatable state, in which the displacement portion has a second configuration; wherein movement from the first configuration to the second configuration induces or increases a curvature along a longitudinal axis of the displacement portion to impart a radial force to the tissue structure.

[001 1] From a yet further aspect, there is provided a tissue displacement device for displacing tissue of a subject, the tissue displacement device comprising: a flexible tube having a wall defining a lumen extending therethrough, the flexible tube having a proximal handle portion, a distal tip, and a displacement portion between the proximal handle portion and the distal tip, for displacement of a tissue structure with which the displacement portion is in contact, in use; at least one inflatable membrane fluidly connected to the lumen of the flexible tube at the displacement portion, the inflatable membrane being deployable between an uninflated state and an inflatable state; wherein the flexible tube is configured to move from a first configuration to a second configuration in which a curvature along a longitudinal axis of the displacement portion is induced or increases to impart a radial force to the tissue structure.

[0012] In certain embodiments of any of the above aspects, the bending between the first configuration and the second configuration comprises imparting or increasing a curvature of the longitudinal axis of the displacement portion.

[0013] In certain embodiments of any of the above aspects, the displacement force is sufficient to displace the tissue structure adjacent to the displacement portion, the tissue structure comprising at least a portion of a subject^'s esophagus into which the displacement portion has been inserted. In certain embodiments, the curvature of the displacement portion in the second configuration is larger than a curvature of the longitudinal axis of the displacement portion in the first configuration. In certain embodiments, the longitudinal axis of the displacement portion is substantially straight when in the first configuration, and curved in the second configuration.

[0014] In certain embodiments, bending of the displacement portion is in a direction substantially orthogonal to the longitudinal axis of the displacement portion. The bending of the displacement portion can cause a radial displacement from the first configuration of about 1 cm to about 10 cm, about 1 to about 9 cm, about 1 to about 8 cm, about 1 to about 7 cm, about 1 to about 6 cm, about 1 to about 5 cm, about 1 to about 4 cm, about 1 to about 3 cm, about 2 cm to about 8 cm, about 2 cm to about 7 cm, about 2 cm to about 6 cm, about 2 cm to about 5 cm, about 2 cm to about 4 cm, about 2 cm to about 3 cm, about 3 cm to about 8 cm, about 3 cm to about 7 cm, about 3 cm to about 6 cm, about 3 cm to about 5 cm, about 4 cm to about 8 cm, about 4 cm to about 7 cm, about 4 cm to about 6 cm, or about 4 cm to about 5 cm.

[0015] In certain embodiments, the displacement portion is about 1 to about 30 cm in length, about 1 to about 25 cm in length, about 1 to about 20 cm in length, about 1 to about 15 cm in length, about 1 to about 10 cm in length, about 5 to about 30 cm in length, about 5 to about 25 cm in length, about 5 to about 20 cm in length, about 5 to about 15 cm in length, about 7 to about 17.5 cm in length, about 10 to about 30 cm in length, about 10 to about 25 cm in length, about 10 to about 20 cm in length, or about 10 to about 15 cm in length. The displacement portion can be sized and shaped in the first configuration for insertion into an esophagus of a patient, and for imparting a sufficient force to move the esophagus in the second configuration.

[0016] In certain embodiments, the inflatable membrane comprises at least one balloon, the balloon being elongate and disposed coaxially around the wall of the flexible tube at the displacement portion. In certain embodiments, the inflatable membrane comprises at least one balloon, the balloon being elongate and disposed around the wall of the flexible tube, an elongate axis of the balloon being off-centred from an elongate axis of the flexible tube. The balloon may be attached to the wall of the flexible tube by a distal balloon end and a proximal balloon end.

[0017] The balloon may have a first longitudinal portion extending between the distal balloon end and the proximal balloon end, and a second longitudinal portion extending between the distal balloon end and the proximal balloon end, the first and second longitudinal portions having different properties such that fluid flow into the balloon will induce the flexible tube at the displacement portion to bend. The first longitudinal portion or the second longitudinal portion may cover less than 50% of a total surface area of the elongate balloon.

[0018] In certain embodiments, the first and second longitudinal portions have different elastic properties. The first and second longitudinal portions may have different wall thicknesses, different strength or stiffness properties, different surface textures, be made from different materials, or combinations of the same. The at least one balloon or the inflatable membrane may comprise a plurality of balloons. [0019] In certain embodiments, a length of the wall defining the flexible tube lumen in the displacement portion is different than a length of the balloon in the inflated state. The wall can be shorter or longer than the length of the balloon in the inflated state. The balloon can be off- centred from the lumen. [0020] In certain embodiments, the balloon may have a curved shape both in the deflated and inflated states. The distal and proximal ends of the balloon may be off-centred relative to a curved longitudinal axis of the balloon.

[0021] In certain embodiments, the inflatable membrane comprises at least one balloon extending radially from the wall of the flexible tube. The inflatable membrane may comprise a plurality of balloons, each balloon extending radially from the wall of the flexible tube, wherein the plurality of balloons are arranged to impart an uneven force on the flexible tube when deployed to impart the second configuration on the displacement portion. At least two of the plurality of balloons may be axially spaced from one another. At least two of the plurality of balloons may be fluidly connected to the flexible tube at radially differing positions. [0022] In certain embodiments, the tissue displacement device further comprises a controller to control fluid flow into and/or out of the at least one balloon. At least one controller may be provided to separately control fluid flow into and/or out of the plurality of balloons.

[0023] In certain embodiments, the flexible tube comprises a wire extending from the handle portion to the distal tip through the lumen, the wire being attachable to the distal tip and actuatable to impart the second configuration. Any one or more of the flexible tube, the wire or the inflatable membrane may be off-centred to accentuate the bend.

[0024] In certain embodiments, at least a portion of the flexible tube has a preformed shape corresponding to the second configuration. A stylet sized and shaped to extend from the handle portion through the lumen of the flexible tube can be provided to maintain the flexible tube in the first configuration until removal of the stylet from the flexible tube.

[0025] In certain embodiments, at least a portion of the flexible tube comprises a shape memory material configured to assume the second configuration at body temperature. A stylet may be provided, sized and shaped to extend from the handle portion through the lumen of the flexible tube to maintain the flexible tube in the first configuration until its removal from the flexible tube.

[0026] In certain embodiments, the handle portion comprises a port for fluid entry into the flexible tube. The fluid can be a liquid or a gas. A valve may be provided for controlling the flow of fluid into and/or out of the flexible tube. The distal tip of the flexible tube may be closed. The inflatable membrane may be in fluid communication with the lumen of the flexible tube through at least one opening formed in the wall of the flexible tube.

[0027] In certain embodiments, the displacement portion is sized and shaped to be inserted through a mouth of the subject into an esophagus of the subject when the inflatable membrane is in an uninflated state and when the displacement portion is in the first configuration.

[0028] From another aspect, there is provided use of the tissue displacement device according to any of the embodiments described above, for moving at least a portion of a subject^'s esophagus away from a left atrium of the subject. [0029] From another aspect, there is provided use of the tissue displacement device according to any of the embodiments described above, in an esophagus of a subject during atrial thermal ablation.

[0030] From a further aspect, there is provided a method for displacing a subject^'s tissue structure comprising: placing the tissue displacement device according to any of the embodiments described above such that the displacement portion is adjacent the tissue structure, deploying the device to obtain the second configuration, wherein deploying the device comprises inflating the inflatable membrane. Deploying may comprise opening a valve at the handle portion to allow fluid to enter the lumen.

[0031] From a further aspect, there is provided a method for displacing a subject^'s tissue structure comprising: placing the tissue displacement device according to any of the embodiments described above such that the displacement portion is adjacent the tissue structure, deploying the device to obtain the second configuration, wherein deploying the device comprises removing a stylet from the lumen.

[0032] It must be noted that, as used in this specification and the appended claims, the singular form "a", "an" and "the" include plural referents unless the context clearly dictates otherwise.

[0033] As used herein, the term "about" in the context of a given value or range refers to a value or range that is within 20%, preferably within 10%, and more preferably within 5% of the given value or range.

[0034] As used herein, the term "and/or" is to be taken as specific disclosure of each of the two specified features or components with or without the other. For example "A and/or B" is to be taken as specific disclosure of each of (i) A, (ii) B and (iii) A and B, just as if each is set out individually herein.

BRIEF DESCRIPTION OF DRAWINGS

[0035] Further aspects and advantages of the present invention will become better understood with reference to the description in association with the following in which:

[0036] Figure 1 is a schematic illustration of a tissue displacement device including an inflatable membrane at a displacement portion of the device, according to an embodiment of the present disclosure;

[0037] Figures 2-13 are schematic illustrations of different embodiments of the inflatable membrane of the device of Figure 1, according to different embodiments of the present disclosure;

[0038] Figure 14 is a schematic illustration of the relative positions of a left atrium of a heart and the esophagus of a subject; [0039] Figure 15 is a schematic illustration of the device of Figure 1 in a first configuration when at least the displacement portion of the device is inserted into the esophagus for displacement of the esophagus away from the left atrium, according to an embodiment of the present disclosure; and

[0040] Figure 16a and 16b are schematic illustrations of the device of Figure 15 in a second configuration, for deflecting the oesophagus in a right lateral direction or a left lateral direction, respectively. DETAILED DESCRIPTION

[0041] The present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including", "comprising", or "having", "containing", "involving" and variations thereof herein, is meant to encompass the items listed thereafter as well as, optionally, additional items. In the following description, the same numerical references refer to similar elements.

[0042] Broadly, there is provided a tissue displacement device 10 for displacing tissue of a subject. In the embodiments described below, the tissue is a portion of an esophagus which is to be displaced away from a left atrium of the subject during left atrial ablation. However, the tissue displacement device 10 can be used to displace other tissues, as well as during different procedures.

[0043] Referring initially to Figure 1 , the tissue displacement device 10 comprises a flexible tube 12 having a wall 14 defining a lumen 16 extending therethrough. The flexible tube 12 has a proximal handle portion 18, a distal tip 20, and a displacement portion 22 between the proximal handle portion 18 and the distal tip 20, for displacement of a tissue structure with which the displacement portion 22 is in contact, in use. Also provided is at least one inflatable membrane 24 fluidly connected to the lumen 16 of the flexible tube 12 at the displacement portion 22, the inflatable membrane 24 being deployable between an uninflated state and an inflatable state. One or more of the inflatable membrane 24, the wall 14 of the flexible tube 12, and the flexible tube 12, at the displacement portion 22, are arranged to move the displacement portion 22 from a first configuration to a second configuration in which a bending along a longitudinal axis 26 of the displacement portion can impart a displacement force to the tissue structure. The displacement force is a radial or lateral force relative to the longitudinal axis 26 of the displacement portion 22.

[0044] Figures 14, 15 and 16a and 16b illustrate, respectively, the relative positioning of the esophagus and the left atrium, the tissue displacement device 10 in use in the first configuration, and the tissue displacement device 10 in use in the second configuration. As can be seen, deployment of the second configuration imparts a deflecting force to the adjacent esophagus tissue structure to displace the tissue structure. In this embodiment, the esophagus is moved away from the atrium to avoid damage during treatment of the atrium. The inflatable membrane 24 can be deflated to remove the deflecting force on the tissue structure.

[0045] The handle portion 18 comprises a handle 28 connected thereto. The handle portion 18 also includes a port 30 for fluid entry into the flexible tube 12. The fluid is air, but can be any other fluid. A valve 32 is provided for controlling the flow of air into and/or out of the flexible tube. In this embodiment, the valve 32 is a syringe although any other valve can be used.

[0046] The distal tip 20 of the flexible tube 12 is closed or fluidly sealed, and there is at least one opening (not shown) formed in the wall 14 of the flexible tube 12 through which the inflatable membrane 24 is in fluid communication with the lumen 16 of the flexible tube 12 . In this way, a flow of air into the lumen 16 through the port 30 can inflate the inflatable membrane 24. The flow rate and volume of air can be controlled using the valve 32 or any other controller.

[0047] At least the displacement portion 22 of the device 10 is sized and shaped to be inserted through a mouth of the subject into the esophagus when the displacement portion 22 is in the first configuration. In this embodiment, in the first configuration, the displacement portion 22 is substantially straight and the inflatable membrane 24 is substantially deflated. The handle portion 18 is arranged to remain outside of the mouth to allow a medical practitioner to hold and manipulate the device 10.

[0048] The displacement portion 22 is sized and shaped such that in the second configuration, the radial displacement of the displacement portion 22 is between about 1 to about 10cm, or about 4-6cm. The movement between the first configuration and the second configuration comprises imparting or increasing a curvature of the longitudinal axis 26 of the displacement portion 22 which in turn can impart a displacement force sufficient to displace the esophageal tissue structure adjacent to the displacement portion 22. The bending of the displacement portion 22 is in a direction substantially orthogonal to the longitudinal axis 26 of the displacement portion 22. The curvature of the displacement portion 22 in the second configuration is greater than a curvature of the displacement portion 22 in the first configuration.

[0049] Referring now to Figure 2, the inflatable membrane 24 comprises at least one balloon 24, the balloon 24 being elongate and disposed coaxially around the wall 14 of the flexible tube 12 at the displacement portion 22. The balloon 24 can be made of any elastomeric material, or the like. The balloon 24 has a distal balloon end 34 and a proximal balloon end 36, both of which have a smaller diameter than a body of the balloon 24. The balloon 24 is attached to the wall 14 of the flexible tube 12 by the distal balloon end 34 and the proximal balloon end 36, and encasing the opening(s) in the wall 14 through which fluid can flow. The balloon 24 has a first longitudinal portion 38 extending between (fully or partially) the distal balloon end 34 and the proximal balloon end 36, and a second longitudinal portion 40 extending between the distal balloon end 34 and the proximal balloon end 36. The first and second longitudinal portions 38, 40 are substantially oppositely facing one another. The first and second longitudinal portions 38, 40 have different properties such that fluid flow into the balloon 24 will cause an asymmetric inflation of the balloon 24 thereby imparting a bend to the displacement portion. The differing properties can be elasticity, strength or stiffness. This can be achieved in a number of different ways. [0050] In the embodiment of Figure 2, the first and second longitudinal portions 38, 40 are made from different materials having different elastic, strength or stiffness properties. [0051] In the embodiment of Figure 3, the first and second longitudinal portions 38, 40 have different surface textures, such as flat and rippled. The rippled longitudinal portion comprises a surface which is creased and can be flattened when inflated, thereby providing more material on one of the longitudinal portions compared to the other.

[0052] In the embodiments of Figures 4 and 5, one of the first and second longitudinal portions 38, 40 are reinforced to induce the asymmetric inflated configuration. In Figure 4, one of the first and second longitudinal portions 38, 40 has a reinforcing layer, such as through co-extrusion, coating, lamination or the like. In Figure 5, the first and second longitudinal portions 38, 40 have different wall thicknesses. In some embodiments, the different properties of the first and second longitudinal portions 38, 40 can be created by primary processes such as co-extrusion, or through secondary processes to add, remove, or reshape material. [0053] In the embodiments of Figures 6 and 7, a length of the flexible tube wall 14 defining the lumen 16 in the displacement portion 22 is different than a length of the balloon 24 when in the inflated state. In Figure 6, the flexible tube wall 14 in the displacement portion 22 encased by the balloon 24 is longer than the inflated length of the balloon. In Figure 7, the flexible tube wall 14 in the displacement portion 22 encased by the balloon 24 is shorter than the inflated length of the balloon 24. Therefore, deploying the balloon 24 to the inflated state causes the flexible tube wall 14 to bend. The embodiment of Figure 8 differs from that of Figures 6 and 7, in that the balloon 24 is off-centred from the flexible tube 12, which can accentuate the buckling and bending of the balloon 24. [0054] In the embodiment of Figures 9a and 9b, the balloon 24 has a pre-formed curved shape which the balloon 24 maintains when inflated. In this embodiment, one of the first and second longitudinal portions 38, 40 is shorter in length than the other. The balloon 24 of Figures 9a and 9b is made by molding, or any other suitable method. Optionally, the distal and proximal ends 34, 36 of this embodiment of the balloon 24 are off-centred relative to the longitudinal axis 42 of the balloon 24 which is curved. [0055] Referring now to Figure 10, there is shown an embodiment of the inflatable membrane 24 which comprises a plurality of balloons 24 extending radially from the wall 14 of the flexible tube 12 within the displacement portion 22. The plurality of balloons 24 are arranged to impart an uneven force on the flexible tube 12 when deployed to impart the second configuration on the displacement portion 22. In this respect, the plurality of balloons 24 are axially spaced from one another and at least two of the plurality of balloons 24 are fluidly connected to the flexible tube 12 at radially differing positions. The number of balloons 24 can be less or more than the three illustrated in Figure 10. As can be seen, the balloons 24 are positioned axially and radially in order to induce a three-point bend to the flexible tube 12. Two outer balloons 24 extend radially in a different direction to an inner balloon 24. The balloons 24 can be deployed separately or together, by the same or differing amounts and to the same or differing pressures.

[0056] In another embodiment (Figure 1 1), the inflatable membrane 24 comprises two balloons 24 which are separately inflatable in differing radial directions and to differing extents of pressure in order to induce bending to the flexible tube 12.

[0057] Referring now to Figure 12, a yet further embodiment of any of the inflatable membranes 24 of Figures 1-11 are shown in which there is provided a wire 44, such as a guide wire, extending from the handle portion 18 to the distal tip 20 through the lumen 16, the wire 44 being attachable to the distal tip 20 and actuatable to impart the second configuration. The flexible tube 12, the wire 44 or the inflatable membrane 24 can be off-centred to accentuate the bend (not shown).

[0058] In the embodiment of Figures 13a and 13b, at least a portion of the flexible tube 12 comprises a shape memory material, such as Nitinol™, configured to assume the second configuration at body temperature. A stylet 46 is provided extending from the handle portion 18 through the lumen 16 of the flexible tube 12 to maintain the flexible tube 12 in the first configuration until its removal from the flexible tube 12. In another embodiment, the flexible tube 12 at the displacement portion 22 has a preformed shape corresponding to the second configuration. The stylet 46 inserted into and extending through the lumen 16 configures the flexible tube 12 into the first configuration. Removal of the stylet 46 allows the flexible tube 12 to resume its preformed shape, i.e. that of the second configuration.

[0059] In use, at least the displacement portion 22 of the tissue displacement device 10 is inserted into a subject^'s esophagus at a location proximate the subject's heart. The device 10 is deployed to move the device 10 from the first configuration to the second configuration in order to move the esophagus away from the left atrium of the subject. The handle 28 includes an indication (not shown) of the displacement direction (e.g. left or right) of the displacement portion 22 such that the medical practitioner can orient the device 10 in the required manner.

[0060] Surprisingly, inventors have found that in embodiments of the present tissue displacement device 10, the device 10 can be inserted into the esophagus and removed when in the first configuration with none or little damage to the tissues of the subject. The device 10 can move reversibly between the first and second configurations. Also, in certain embodiments, the tissue structure such as the esophagus can be moved temporarily away from a treatment site, such as the left atrium, to avoid thermal damage. In certain embodiments, local bleeding is avoided or minimized by using an inflatable membrane and a curved configuration to apply lateral force to the tissue structure. Furthermore, in certain embodiments, the curvature of the second configuration of the displacement portion 22 can be controlled which enables the device 10 to be adapted and used on subjects having differing anatomies. Certain embodiments of the device also enable a clear visualisation of the deflection of the tissue structure without requiring barium ingestion to aid visualisation.

[0061] Variations and modifications will occur to those of skill in the art after reviewing this disclosure. The disclosed features may be implemented, in any combination and subcombinations (including multiple dependent combinations and subcombinations), with one or more other features described herein. The various features described or illustrated above, including any components thereof, may be combined or integrated in other systems. Moreover, certain features may be omitted or not implemented. Examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the scope of the information disclosed herein. [0062] It should be appreciated that the invention is not limited to the particular embodiments described and illustrated herein but includes all modifications and variations falling within the scope of the invention as defined in the appended claims.

Claims

CLAIMS What is claimed is:

1. A tissue displacement device for displacing tissue of a subject, the tissue displacement device comprising: a flexible tube having a wall defining a lumen extending therethrough, the flexible tube having a proximal handle portion, a distal tip, and a displacement portion between the proximal handle portion and the distal tip, for displacement of a tissue structure with which the displacement portion is in contact, in use; at least one inflatable membrane fluidly connected to the lumen of the flexible tube at the displacement portion, the inflatable membrane being deployable between an uninflated state and an inflatable state; wherein one or both of the inflatable membrane and the flexible tube at the displacement portion are arranged to move the displacement portion from a first configuration to a second configuration in which a bending along a longitudinal axis of the displacement portion can impart a displacement force to the tissue structure.

2. The tissue displacement device of claim 1 , wherein the bending between the first configuration and the second configuration comprises imparting or increasing a curvature of the longitudinal axis of the displacement portion.

3. The tissue displacement device of claim 1 or 2, wherein the displacement force is sufficient to displace the tissue structure adjacent to the displacement portion, the tissue structure comprising at least a portion of a subject^'s esophagus into which the displacement portion has been inserted.

4. The tissue displacement device of claim 2 or claim 3, wherein the curvature of the displacement portion in the second configuration is larger than a curvature of the longitudinal axis of the displacement portion in the first configuration.

5. The tissue displacement device of any one of claims 2-4, wherein the longitudinal axis of the displacement portion is substantially straight when in the first configuration, and curved in the second configuration.

6. The tissue displacement device of any one of claims 1-5, wherein the bending of the displacement portion is in a direction substantially orthogonal to the longitudinal axis of the displacement portion.

7. The tissue displacement device of any one of claims 1-6, wherein the bending of the displacement portion causes a radial displacement of about 1 cm to about 10 cm, about 1 to about 9 cm, about 1 to about 8 cm, about 1 to about 7 cm, about 1 to about 6 cm, about 1 to about 5 cm, about 1 to about 4 cm, about 1 to about 3 cm, about 2 cm to about 8 cm, about 2 cm to about 7 cm, about 2 cm to about 6 cm, about 2 cm to about 5 cm, about 2 cm to about 4 cm, about 2 cm to about 3 cm, about 3 cm to about 8 cm, about 3 cm to about 7 cm, about 3 cm to about 6 cm, about 3 cm to about 5 cm, about 4 cm to about 8 cm, about 4 cm to about 7 cm, about 4 cm to about 6 cm, or about 4 cm to about 5 cm, from the first configuration.

8. The tissue displacement device of any one of claims 1-7, wherein the displacement portion is about 1 to about 30 cm in length, about 1 to about 25 cm in length, about 1 to about 20 cm in length, about 1 to about 15 cm in length, about 1 to about 10 cm in length, about 5 to about 30 cm in length, about 5 to about 25 cm in length, about 5 to about 20 cm in length, about 5 to about 15 cm in length, about 7 to about 17.5 cm in length, about 10 to about 30 cm in length, about 10 to about 25 cm in length, about 10 to about 20 cm in length, or about 10 to about 15 cm in length.

9. The tissue displacement device of any one of claims 1-8, wherein the inflatable membrane comprises at least one balloon, the balloon being elongate and disposed coaxially around the wall of the flexible tube at the displacement portion.

10. The tissue displacement device of any one of claims 1-8, wherein the inflatable membrane comprises at least one balloon, the balloon being elongate and disposed around the wall of the flexible tube, an elongate axis of the balloon being off-centred from an elongate axis of the flexible tube.

11. The tissue displacement device of claim 9 or claim 10, wherein the balloon is attached to the wall of the flexible tube by a distal balloon end and a proximal balloon end.

12. The tissue displacement device of claim 1 1, wherein the balloon has a first longitudinal portion extending between the distal balloon end and the proximal balloon end, and a second longitudinal portion extending between the distal balloon end and the proximal balloon end, the first and second longitudinal portions having different properties such that fluid flow into the balloon will induce the flexible tube at the displacement portion to bend.

13. The tissue displacement device of claim 12, wherein the first longitudinal portion or the second longitudinal portion covers less than 50% of a total surface area of the elongate balloon.

14. The tissue displacement device of claim 12 or claim 13, wherein the first and second longitudinal portions have different elastic properties.

15. The tissue displacement device of any one of claims 12-14, wherein the first and second longitudinal portions have different wall thicknesses.

16. The tissue displacement device of any one of claims 12-15, wherein the first and second longitudinal portions have different strength or stiffness properties.

17. The tissue displacement device of any one of claims 12-16, wherein the first and second longitudinal portions have different surface textures.

18. The tissue displacement device of any one of claims 12-17, wherein the first and second longitudinal portions are made from different materials.

19. The tissue displacement device of any one of claims 9-18, wherein the at least one balloon comprises a plurality of balloons.

20. The tissue displacement device of any one of claims 9-19, wherein a length of the wall defining the flexible tube lumen in the displacement portion is different than a length of the balloon in the inflated state.

21. The tissue displacement device of claim 20, wherein the wall is shorter or longer than the length of the balloon in the inflated state.

22. The tissue displacement device of claim 21, wherein the balloon is off-centred from the lumen.

23. The tissue displacement device of any one of claims 9-22, wherein the balloon has a curved shape both in the deflated and inflated states.

24. The tissue displacement device of claim 23 when dependent on claim 1 1, wherein the distal and proximal ends of the balloon are off-centred relative to a curved longitudinal axis of the balloon.

25. The tissue displacement device of any one of claims 1 -8, wherein the inflatable membrane comprises at least one balloon extending radially from the wall of the flexible tube.

26. The tissue displacement device of claim 25, wherein the inflatable membrane comprises a plurality of balloons, each balloon extending radially from the wall of the flexible tube, wherein the plurality of balloons are arranged to impart an uneven force on the flexible tube when deployed to impart the second configuration on the displacement portion.

27. The tissue displacement device of claim 26, wherein at least two of the plurality of balloons are axially spaced from one another.

28. The tissue displacement device of claim 26 or claim 27, wherein at least two of the plurality of balloons are fluidly connected to the flexible tube at radially differing positions.

29. The tissue displacement device of any one of claims 9-28, further comprising a controller to control fluid flow into and/or out of the at least one balloon.

30. The tissue displacement device of any one of claims 19-29, further comprising at least one controller to separately control fluid flow into and/or out of the plurality of balloons.

31. The tissue displacement device of any one of claims 1-30, wherein the flexible tube comprises a wire extending from the handle portion to the distal tip through the lumen, the wire being attachable to the distal tip and actuatable to impart the second configuration.

32. The tissue displacement device of claim 31, wherein any one or more of the flexible tube, the wire or the inflatable membrane is off-centred to accentuate the bend.

33. The tissue displacement device of any one of claims 1-32, wherein at least a portion of the flexible tube has a preformed shape corresponding to the second configuration.

34. The tissue displacement device of any one of claims 1-32, wherein at least a portion of the flexible tube comprises a shape memory material configured to assume the second configuration at body temperature.

35. The tissue displacement device of claim 33 or claim 34, further comprising a stylet extending from the handle portion through the lumen of the flexible tube to maintain the flexible tube in the first configuration until its removal from the flexible tube.

36. The tissue displacement device of any one of claims 1-35, wherein the handle portion comprises a port for fluid entry into the flexible tube.

37. The tissue displacement device of any one of claims 1-36, wherein the fluid is a liquid or a gas.

38. The tissue displacement device of any one of claims 1 -37, further comprising a valve for controlling the flow of fluid into and/or out of the flexible tube.

39. The tissue displacement device of any one of claims 1 -38, wherein the distal tip of the flexible tube is closed.

40. The tissue displacement device of any one of claims 1-39, wherein the inflatable membrane is in fluid communication with the lumen of the flexible tube through at least one opening formed in the wall of the flexible tube.

41. The tissue displacement device of any one of claims 1-40, wherein the displacement portion is sized and shaped to be inserted through a mouth of the subject into an esophagus of the subject when the inflatable membrane is in an uninflated state and when the displacement portion is in the first configuration.

42. A tissue displacement device for displacing tissue of a subject, the tissue displacement device comprising: a flexible tube having a wall defining a lumen extending therethrough, the flexible tube having a proximal handle portion, a distal tip, and a displacement portion between the proximal handle portion and the distal tip, for displacement of a tissue structure with which the displacement portion is in contact, in use; at least one inflatable membrane fluidly connected to the lumen of the flexible tube at the displacement portion, the inflatable membrane being deployable between an uninflated state, in which the displacement portion has a first configuration, and an inflatable state, in which the displacement portion has a second configuration; wherein movement from the first configuration to the second configuration induces or increases a curvature along a longitudinal axis of the displacement portion to impart a radial force to the tissue structure.

43. A tissue displacement device for displacing tissue of a subject, the tissue displacement device comprising: a flexible tube having a wall defining a lumen extending therethrough, the flexible tube having a proximal handle portion, a distal tip, and a displacement portion between the proximal handle portion and the distal tip, for displacement of a tissue structure with which the displacement portion is in contact, in use; at least one inflatable membrane fluidly connected to the lumen of the flexible tube at the displacement portion, the inflatable membrane being deployable between an uninflated state and an inflatable state; wherein the flexible tube is configured to move from a first configuration to a second configuration in which a curvature along a longitudinal axis of the displacement portion is induced or increases to impart a radial force to the tissue structure.

44. Use of the tissue displacement device according to any one of claims 1-43, for moving at least a portion of a subject^'s esophagus away from a left atrium of the subject.

45. Use of the tissue displacement device according to any one of claims 1-44, in an esophagus of a subject during atrial thermal ablation.

46. A method for displacing a subject's tissue structure comprising: placing the displacement device of any one of claims 1-43 such that the displacement portion is adjacent the tissue structure, deploying the device to obtain the second configuration, wherein deploying the device comprises inflating the inflatable membrane.

47. The method of claim 46, wherein deploying comprises opening a valve at the handle portion to allow fluid to enter the lumen.

48. A method for displacing a subject^'s tissue structure comprising: placing the displacement device of any one of claims 1 -43 such that the displacement portion is adjacent the tissue structure, deploying the device to obtain the second configuration, wherein deploying the device comprises removing a stylet from the lumen.