Venous ablation system

Abstract

A venous ablation system comprising a bristle device. The bristle device comprises a distal portion comprising a bristle portion. The bristle portion comprises a core and a plurality of resiliently flexible bristles extending at least radially outwardly from the core. The bristles have a collapsed delivery configuration and an expanded deployed configuration in which the bristles are configured to contact the vessel wall. The system also comprises a delivery portion configured to deliver the bristle portion through a delivery catheter, the delivery portion at least partially integral with the core. The bristle device comprises a proximal portion electrically connected to the distal portion. The proximal portion is configured to electrically connect to an electrical source.

Description

[0001] VENOUS ABLATION SYSTEM

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to venous ablation systems and methods. More particularly, the present disclosure relates to an at least partially non-thermal, non-tumescent venous ablation system.

[0004] BACKGROUND

[0005] Superficial venous reflux and chronic venous insufficiency, presenting as varicose veins in the lower limbs, may be treated by a number of different methods. Some treatment methods involve thermal ablation of the affected vessel, for example by radiofrequency ablation or endovenous laser ablation, which causes significant patient pain. Some methods include the use of tumescent fluids during treatment.

[0006] Non-thermal, non-tumescent treatments involve the use of implanted materials like sclerosants and cyanoacrylate adhesives. There is a need for at least partially non-thermal, non-tumescent treatments which do not use such implanted materials.

[0007] SUMMARY

[0008] According to a first aspect of the invention defined by the appended claims, there is provided a venous ablation system comprising a bristle device, the bristle device comprising: a distal portion comprising a bristle portion, the bristle portion comprising a core and a plurality of resiliently flexible bristles extending at least radially outwardly from the core, the bristles having a collapsed delivery configuration and an expanded deployed configuration in which the bristles are configured to contact the vessel wall; and a delivery portion configured to deliver the bristle portion through a delivery catheter, the delivery portion at least partially integral with the core; the bristle device comprising a proximal portion electrically connected to the distal portion, the proximal portion configured to electrically connect to an electrical source.

[0009] According to a second aspect of the invention defined by the appended claims, there is provided a method of manufacturing a venous ablation system, comprising: forming a bristle portion at a distal portion of the venous ablation system by forming a plurality of resiliently flexible bristles on a core, such that the plurality of bristles extend at least radially outwardly from the core, the bristles having a collapsed delivery configuration and an expanded deployed configuration in which the bristles are configured to contact the vessel wall; wherein the core is at least partially integral with a delivery portion configured to deliver the bristle portion through a delivery catheter; the method comprising electrically connecting the distal portion to a proximal portion of the venous ablation system, the proximal portion configured to electrically connect to an electrical source.

[0010] According to a third aspect, there is provided a method of closing a blood vessel of a patient, comprising the steps of: inserting a delivery catheter into the vasculature of the patient; positioning a distal portion of the delivery catheter at a target site in the blood vessel; delivering a bristle device of a venous ablation system to the distal portion of the delivery catheter; deploying the bristle device from the delivery catheter so that the flexible bristles contact the vessel wall; and at least one of the following: translating the bristle device to denude the vessel wall; and / or delivering electrical energy to the distal portion. The venous ablation system may be any of the venous ablation systems disclosed herein.

[0011] BRIEF DESCRIPTION OF THE DRAWINGS

[0012] To enable better understanding of the present disclosure, and to show how the same may be carried into effect, reference will now be made, by way of example only, to the accompanying schematic drawings, in which:

[0013] Fig. 1A shows a schematic side view of a venous ablation system in a first configuration according to one or more embodiments shown and described herein;

[0014] Fig. IB shows a schematic side view of the venous ablation system of Fig. 1A in a second configuration according to one or more embodiments shown and described herein;

[0015] Fig. 1C shows a schematic view of a radiofrequency generator for a venous ablation system according to one or more embodiments shown and described herein;

[0016] Fig. ID shows a schematic side view of a flexible bristle for a bristle device for a venous ablation system according to one or more embodiments shown and described herein;

[0017] Fig. 2 shows a schematic side view of a bristle device for a venous ablation system according to one or more embodiments shown and described herein; Fig. 3 A shows a schematic perspective view of a method of manufacturing a bristle device for a venous ablation system according to one or more embodiments disclosed herein;

[0018] Fig. 3B shows a schematic perspective view of the bristle device manufactured according to the method of Fig. 3 A according to one or more embodiments disclosed herein;

[0019] Fig. 4 shows a schematic cross-sectional side view of a bristle device for a venous ablation system according to one or more embodiments disclosed herein;

[0020] Fig. 5 shows a schematic cross-sectional side view of another bristle device for a venous ablation system according to one or more embodiments disclosed herein;

[0021] Fig. 6 shows a schematic cross-sectional side view of another bristle device for a venous ablation system according to one or more embodiments disclosed herein;

[0022] Fig. 7 shows a schematic cross-sectional side view of another bristle device for a venous ablation system according to one or more embodiments disclosed herein; and

[0023] Fig. 8 shows a schematic cross-sectional side view of another bristle device for a venous ablation system according to one or more embodiments disclosed herein.

[0024] DETAILED DESCRIPTION

[0025] As used herein, the term “venous ablation system”, may be understood to mean a system comprising a device which causes one or more of mechanical damage, electrical damage or thermal damage to the vessel walls to induce shutdown of the vessel.

[0026] As used herein, the term “integral”, in the context of one element being integral with another element, may be understood to mean that the elements form a singular unitary body.

[0027] As used herein, a ‘collapsed delivery configuration’ of an element may refer to a configuration of the element which has a smaller radial extent than an ‘expanded deployed configuration’ of the element.

[0028] Throughout this disclosure, the term ‘tube wall’ may refer to the wall of a tube which extends along the longitudinal axis of the tube. The tube wall may be continuous or discontinuous. The tube may take any cross-sectional shape, for example circular, oval or square. The tube may take one or multiple different cross-sectional shapes along its length.

[0029] Throughout this disclosure, the term ‘tube’ may refer to any element which has a tube wall in which different portions of the tube wall oppose each other across a longitudinal axis. For example, the tube wall may be curved (e.g. having a circular cross-section) around the longitudinal axis of the tube such that opposite sides of the tube wall oppose each other. The tube may or may not have a lumen extending along any portion of its longitudinal axis.

[0030] Throughout this disclosure, an element referred to as being ‘clamped’ by another clamping element, refers to the clamping element directly or indirectly providing forces (for example, opposing forces) on the element so as to restrain the element. The clamping element may directly or indirectly contact the clamped element.

[0031] Throughout this disclosure, a ‘shrinkable material’ may refer to a material which shrinks in a particular direction upon a particular treatment. Such a treatment may be a heat and / or or chemical treatment. As would be understood by the skilled person, the shrinkable materials themselves shrink without an external force being applied to them, for example, by crimping.

[0032] Throughout this disclosure reference is made to a delivery portion being integral with a core of a bristle portion. Where the delivery portion and / or bristle portion comprises a plurality of elements, it will be understood to mean that at least one element of the delivery portion is integral with at least one element of the bristle portion. In other words, the delivery portion may be at least partly integral with the bristle portion. As such, the devices disclosed herein are not configured to be implanted into the body and under normal use of the device the bristle portion remains integral with the delivery portion.

[0033] Throughout this disclosure reference is made to venous ablation systems comprising a bristle device comprising a plurality of flexible bristles. It will be understood that the term “flexible bristle” refers to any bristle which is resiliently deformable. In any of the devices disclosed herein, the flexible bristles may be made of any resiliently deformable and conductive material such as stainless steel, Elgiloy or Nitinol, or Nylon. Other suitable materials may also be used, such as any suitable shape memory metal or metal alloy or resiliently deformable conductive or non-conductive (electrically insulating) material, or a resiliently deformable conductive material coated in a non-conductive material. The diameter of an individual flexible bristle may range from 0.036mm (0.0014 inches) to 0.053mm (0.0021 inches). For example, the diameter of an individual flexible bristle may be 0.0381mm (0.0015 inches), 0.0445mm (0.00175 inches) or 0.0508mm (0.002 inches). The diameter of an individual flexible bristle may be greater than 0.1mm, and in some examples up to 0.15mm. The average radial diameter of the radial profile of the bristle device formed by the expanded flexible bristles in an unconstrained configuration may range from 5 mm to 30mm.

[0034] It will further be understood that in preferred examples the flexible bristles may be of a sufficient stiffness to be able to cause damage to the vessel wall. In some embodiments, the stiffness of the flexible bristles (i.e. modulus of elasticity) may be at least 3 GPa, for example between 3 GPa and 310 GPa.

[0035] Throughout this disclosure, the term “conductive element” may be any element which comprises a conductive material and is configured to conduct electrical energy. The conductive element may comprise one or more components such as one or more conductive wires, sleeves, meshes, cylinders, coatings or the like.

[0036] Throughout this disclosure, the term “conductive material” will be understood to mean any suitable electrically conductive material, such as any conductive metal, alloy or the like. Examples include stainless steel, Elgiloy or Nitinol.

[0037] Throughout this disclosure, the term “radiofrequency” will be understood to mean any frequency of the order of kHz or greater (for example 1kHz or greater). The terms “RF” and “radiofrequency” are interchangeable.

[0038] Fig. 1A shows a schematic side view of a venous ablation system comprising a bristle device 1 in a delivery configuration. The bristle device 1 may be suitable for denuding a vessel wall. The bristle device 1 comprises a distal portion D comprising a bristle portion 2. The bristle portion 2 comprises a core 3 and a plurality of resiliently flexible bristles 4 extending at least radially outwardly from the core 3, and partially longitudinally along the core 3. The bristles 4 have a collapsed delivery configuration, as shown in Fig. 1A, in which the bristles 4 fit inside a delivery catheter 7 for delivering the bristle device 1 to a target site in the vasculature. The bristles 4 also have an expanded delivery configuration, as shown in Fig. IB, in which the bristles are configured to contact and, in some embodiments, denude the vessel wall 9. The bristle device 1 also comprises a delivery portion 5 configured to deliver the bristle portion 2 through the delivery catheter 7. The delivery portion 5 may be any suitable element configured to slidably fit inside the delivery catheter 7 and having a length such that it is extendable from a proximal portion of the delivery catheter 7 to a distal portion of the delivery catheter 7. The delivery portion 5 is at least partially integral with the core 3, that is to say, at least one element of the delivery portion 5 forms a unitary body with at least one element of the bristle portion 2, and in particular at least one element of the core 3. In some preferred embodiments, the plurality of bristles 4 each penetrate through the core 3 such that the core 3 secures the bristles 4 to the bristle portion 2. In other embodiments, the plurality of bristles 4 are attached to or formed on the surface of the core 3 without penetrating the core 3, for example by welding or adhesive, or by cutting the core 3 itself to form the bristles 4, for example as disclosed for the implant comprising bristles in US patent number US 10,660,645 B2. The bristle device 1 may comprise one or more radiopaque markers 8 which are viewable under radiography (for example X-ray radiography) for locating the bristle device 1. The radiopaque markers 8 may be provided at any suitable location on the bristle device 1, for example proximal to the most proximal bristle 4 of the device 1, longitudinally between the ends of neighbouring bristle segments, within a bristle segment or distal to the most distal bristle 4 of the device 1. For example, the radiopaque markers 8 may comprise an annulus or tube or radiopaque material mounted on the exterior of the core 3.

[0039] It is noted that in some embodiments, some or all of the flexible bristles 4 may be conductive and electrically connected to the distal portion 2 such that they are configured to deliver electrical energy to the vessel wall. In some embodiments, only some of the flexible bristles may be conductive and electrically connected to the distal portion 2, whereas others may be electrically insulated such that they are not configured to deliver electrical energy to the vessel wall (for example, made of a non-conductive material or coated in a non-conductive material). In some embodiments, some or all of the flexible bristles 4 may be electrically insulated such that they are not configured to deliver electrical energy to the vessel wall.

[0040] In some embodiments, a first set of the bristles 4 may include electrically conductive bristles and be configured to delivery electrical energy to the vessel wall, allowing for more localised and accurate heating of the target site of the vessel wall. A second set of the bristles 4 may be non-conductive and be configured to mechanically score or denude the vessel wall. The non-conductive set of bristles may comprise barbs or hooks to assist in the mechanical scoring whereas the conductive bristles may be free from barbs or hooks. Further, the non-conductive set of bristles may have a different (e.g. higher) stiffness than the conductive set of bristles to assist in scoring the vessel wall. The venous ablation system comprises a proximal portion P electrically connected to the distal portion D via one or more electrical connections. In some embodiments, the proximal portion P is electrically connected, via one or more electrical connections, to one or more, and preferably all, of the plurality of bristles 4, wherein the electrically connected bristles are electrically conductive and configured to deliver electrical energy to the vessel wall. The proximal portion is configured to electrical connect to an electrical source G, which in some embodiments is a radiofrequency (RF) generator. In some embodiments, the delivery portion 5 may be made of a conductive material and the proximal portion of the venous ablation system may be a proximal part 5a of the delivery portion. In other embodiments, the proximal portion of the venous ablation system may be a proximal part of a separate optional conductive element such as a conductive wire C which runs alongside the delivery portion 5 and is electrically connected to the bristles 4. In embodiments where the delivery portion 5 is conductive, the conductive element such as conductive wire C may be omitted.

[0041] It is noted that in some embodiments, the delivery portion 5 may comprise a conductive material and the core 3 may be entirely made of a non-conductive material (in such examples the delivery portion 5 may comprise a conductive part and a non-conductive part, and the core 3 may be integral with the non-conductive part of the delivery portion 5, embodiments of which are described later with reference to Figs. 2 to 8). In such embodiments, proximal part 5a of the delivery portion 5 may comprise the proximal portion of the venous ablation system configured to electrically connect to the electrical source G. In some embodiments, including those where at least some bristles are electrically conductive and configured to delivery electrical energy to the vessel wall, the distal part of the delivery portion 5 may be electrically connected to one or more of the plurality of bristles 4 by any suitable conducting element, for example one or more conducting wires extending between the delivery portion 5 and the bristles 4, a conducting mesh placed over the core 3 and extending between the delivery portion 5 and the bristles 4, or a conductive coating on the core 3 extending between the delivery portion 5 and the bristles 4.

[0042] In some embodiments, the core 3 may comprise an electrically conductive material and the delivery portion 5 may be entirely non-conductive (in such examples the core 3 may comprise a conductive part and a non-conductive part - for example wires 10a and 10b may be conductive and non-conductive, respectively - and the delivery portion 5 may be non-conductive and integral with the non-conductive part of the core 3). Exemplary embodiments are discussed in detail in the foregoing with reference to Figs. 2 to 8. In such embodiments, the proximal portion of the venous ablation system may be a proximal portion of a separate conductive element such as a conductive wire C, conductive sleeve or mesh, extending alongside the delivery portion 5 from a proximal portion of the venous ablation system, alongside the delivery portion 5 and electrically connected to the conductive part of the core 3.

[0043] It will therefore be appreciated that the electrical connection between the proximal portion P of the venous ablation system and the distal portion D may be made though one or both of the delivery portion 5 and the core 3, wherein a separate conducting element C is provided to extend between the non-conductive parts of the venous ablation system in embodiments where one or both of the delivery portion 5 and the core 3 are non- conductive. For example, in some embodiments, the electrical energy may be configured to pass from, in order, the proximal portion P of the system, a conductive element C extending alongside the delivery portion 5, and to the core 3 (and optionally to the bristles 4, if conductive). In other embodiments, the electrical energy may be configured to pass from, in order, the proximal portion P of the system, the delivery portion 5, and a conductive element C extending alongside the core 3 (and optionally to the bristles 4, if conductive). In still further embodiments, the electrical energy may be configured to pass from, in order, the proximal portion P of the system, and a conductive element C extending alongside both the delivery portion 5 and the core 3 (and optionally to the bristles 4, if conductive). In yet further embodiments, the electrical energy may be configured to pass from, in order, the proximal portion P of the system, the delivery portion 5, and the core 3 (and optionally to the bristles 4, if conductive).

[0044] The electrical source G may be any suitable electrical source for delivering electrical energy to the distal portion D of the ablation system such that the vessel wall is heated. For example, in some embodiments the electrical source G may be an AC or DC source configured to deliver electrical energy to a resistive component at the distal portion D of the system such that the vessel wall is heated, to encourage vessel shutdown. In some embodiments, the electrical source G may be an RF generator which may be any suitable generator for transmitting radiofrequency electrical energy as known in the art, and may be a voltage or current RF generator. Fig. 1C shows a schematic view of an exemplary electrical source G. The generator G may be connectable to, or comprise a power supply unit 900 for providing electrical power to all of the components of the generator G. The generator G comprises any suitable electrical generation module 912 known in the art, operable to generate electrical energy at an output 902 to which the proximal portion P of the venous ablation system is connectable. The electrical source G may be an AC source configured to supply energy having a frequency of one or both of at least 100Hz and / or less than or equal to 100GHz. More preferably, electrical source G may be configured to supply radiofrequency energy having a frequency of one or both of at least 20kHz and / or less than or equal to 100GHz. More preferably, electrical source G may be configured to supply radiofrequency energy having a frequency of one or both of at least 350kHz and / or less than or equal to 100GHz. More preferably, electrical source G may be configured to supply radiofrequency energy having a frequency of one or both of at least 350kHz and / or less than or equal to 500kHz. Alternatively, or additionally, the electrical source G may be configured to supply electrical energy having a power of one or both of at least 0.01W and / or less than 100W.

[0045] The electrical source G may be configured to electrically connect to the distal portion D in a monopolar configuration and the electrical source G may be configured to provide monopolar current at the distal portion D. That is to say, the electrical source G may be configured to form a single electrical connection with the distal portion D such that a single electrical pole is formed at the distal portion D of the venous ablation system (for example conductive element C comprises a single wire or the like which electrically connects the proximal portion P to the distal portion D). In some embodiments a separate electrical lead may be provided to be placed on the exterior of the patient to complete the electrical circuit.

[0046] In some embodiments, the electrical source G may be configured to electrically connect to the distal portion D in a bipolar configuration and the electrical source G may be configured to provide bipolar current at the distal portion D. That is to say, the electrical source G may be configured to form a plurality of electrical connections with the distal portion such that two electrical pols are formed at the distal portion D and electrical current flows between the poles. For example, conductive element C may comprise two or more conducting wires or the like which are electrically insulated from one another and electrically connected to different parts of the distal portion D, so that current flows between the different parts of the distal portion D. For example, the core 3 may comprise a proximal core part 3a and a distal core part 3b which are connected but electrically isolated from one another (for example by a non-conductive connector such as radiopaque marker 8 mounted between the parts 3a and 3b). A first electrical connection may be made between the electrical source G and the proximal core part 3a (e.g. via delivery portion 5) and a second electrical connection may be made between the electrical source G and the distal core part 3b (e.g. via conductive element C). When the electrical source G provides electrical energy, electrical current will flow between proximal and distal core parts 3a and 3b. In embodiments where at least some of the bristles 4 on each segment 6a, 6b are electrically conductive, the electrical current will flow through the vessel 9 between the segments 6a and 6b, allowing for more localised heating.

[0047] In some embodiments, the electrical energy may be distributed equally about all of the bristles 4. That is, all of the bristles 4 may be electrically conductive and connectable to the electrical source G and configured to deliver electrical energy to the vessel walls. In other embodiments, the electrical energy may be distributed about a subset of the bristles 4. That is, only some of the bristles 4 may be electrically conductive and connectable to the electrical source G and configured to deliver electrical energy to the vessel walls, whereas other bristles 4 are non-conductive and not configured to deliver.

[0048] The electrical source G may be configured to provide electrical energy to the distal portion D in one or more of the following ways: continuously, in pulses, or intermittently. The electrical source G may be configured to provide the electrical energy according to an automatic setting (for example according to instructions of a program saved in a memory of the electrical source G), or the electrical source G may comprise a user interface enabling the user to select the delivery parameters (for example, one or more of: continuous / pulsed / intermittent; duration; power; frequency and so on).

[0049] The electrical energy delivered by the electrical source G causes the site of the vessel to be heated, whether locally on the vessel wall via the contact points of electrically conductive bristles or in a less localised manner by heating one or more other components (such as the core) proximal the vessel wall. Heating of the vessel encourages vessel shutdown.

[0050] In preferred embodiments the electrical energy is RF energy. In more preferred embodiments, the RF energy is delivered directly to the vessel wall via one or more electrically conductive bristles. This provides heat in a highly localised manner at the vessel wall where the bristles contact it.

[0051] Advantageously, in embodiments where the electrical energy is used in combination with mechanical scoring caused by movement of the device (when the bristles are configured to denude the vessel wall due to their mechanical strength), a lower electrical power can be used compared to applications in which only electrical energy is used to close the vessel. This results in less generation of heat which reduces discomfort for the patient. The electrical source G may be configured to provide one or both of a fixed frequency and / or a fixed power. In some embodiments the electrical source G may further comprise a user interface 904, that allows user interaction and adjustment of the frequency and power settings. The user interface 904 may be any suitable interface for receiving user inputs and may comprise elements such as a display screen, buttons, knobs, or touch-sensitive controls. The user may interact with the user interface 904 to select a desired power and / or frequency and the electrical source G may be configured to output radiofrequency energy to the output 902 at the power and / or frequency selected by the user. The electrical source G may further comprise a memory 906, a processor 908 and a controller 910. The memory 906 may store instructions which, when executed by the processor 908, cause the electrical source G to operate to provide the electrical energy to the output 902. The controller 910 may be configured to control operation of the frequency generation module 912. The processor 908 may receive the inputs from the user interface 904 and provide instructions to the controller 910 to cause the frequency generation module 912 to output electrical energy to the output 902 at the selected parameters of power and / or frequency. It will be appreciated that the electrical source G of Fig. 1C is exemplary only and any suitable electrical source in the art may be used.

[0052] The proximal portion of the venous ablation system may be configured to connect to the output 902 using any suitable mechanism. For example, the output 902 and proximal portion may comprise connector ports, such as male and female connector ports, configured to mate with one another. In other examples, the output 902 and the proximal portion may comprise magnetic coupling ports configured to connect to one another. In yet other examples, the output 902 may comprise a threaded connection and the proximal portion may be configured to be threaded onto the output 902 to make the electrical connection. It will be appreciated that the present disclosure is not limited to any type of connection and any suitable form of electrical connection between the electrical source G and the proximal portion of the venous ablation system may be used.

[0053] Fig. IB shows the bristle device 1 of Fig. 1A in a second, expanded deployed configuration. In use, the delivery catheter 7 is navigated to a target site in the vasculature, for example a varicose vein or other vessel for closure. The bristle device 1 is loaded into the delivery catheter 7 from a proximal end of the delivery catheter 7, and the delivery portion 5 is pushed in a distal direction through the delivery catheter 7 so that the bristle portion 2 reaches the distal tip of the delivery catheter 7. To deploy the bristle device 1, the delivery catheter 7 is moved proximally relative to the bristle device 1 (or the bristle device 1 is moved distally relative to the delivery catheter 7) such that the bristle device 1 is exposed from the distal tip of the delivery catheter 7, as shown in Fig. IB. The resiliently flexible bristles 4 self-expand from the collapsed delivery configuration to the expanded deployed configuration in which the bristles 4 contact the vessel wall 9. The proximal portion P of the venous ablation system, if not already connected, is electrically connected to the electrical source G and electrical energy is delivered to the distal portion D, and heat is delivered to the vessel wall (indicated by the arrows E). The heat energy elicits a reaction at the vessel wall and assists in closing the vessel. Alternatively, or additionally, if the bristles 4 are configured to denude the vessel wall, the bristle device 1 may also (before, during or after the electrical energy is applied) be moved proximally and distally and / or rotated such that the bristles 4 denude or score the venous endothelium, indicated by the arrow A, which elicits a local reaction that results in shutting down the vessel and complete closure of the varicose veins. Advantageously, diseased or varicosed veins with stagnant or refluxing flow rapidly shut down when treated by denudation or scoring, whereas healthy veins with normal blood flow do not respond as readily to this treatment.

[0054] In some embodiments, as illustrated in Fig. 1 A, the bristle device 1 comprises a first set 6a of bristles 4 and a second set 6b of bristles 4, wherein the first set 6a of bristles 4 are configured to extend in a proximal direction in the expanded deployed configuration (as shown in Fig. IB), and the second set 6b of bristles 4 are configured to extend in a distal direction in the expanded deployed configuration (as shown in Fig. IB), the distal direction opposite to the proximal direction. In some embodiments, the bristles 4 extend in a single longitudinal direction in the deployed configuration (either distally or proximally, but not both). That is, in some embodiments, the bristle device 1 may comprise only bristles 4 extending distally, or only bristles 4 extending proximally. The first and second sets 6a, 6b of bristles 4 may each be grouped into a single segment located away from the other sets of bristles 4, as illustrated in Fig. 1A (i.e., there may be provided a gap between the bristle segments which is larger than the gap between neighbouring bristles within a single segment). The bristle device 1 may comprise more than two bristle segments, wherein each segment comprises only distally or proximally extending bristles 4. Having a set of bristles 4 that point distally and a set of bristles that point proximally in the bristle device 1 may cause damage to the vessel wall 9 when the bristle device 1 is moved proximally and distally, rather than only causing damage in a single direction of movement.

[0055] Fig. ID shows a schematic view of a flexible bristle 4 for a bristle device of a venous ablation system according to one or more embodiments. The flexible bristle 4 may comprise one or more hooks or barbs 40 along the length of the bristle 4. Alternatively, or additionally, the flexible bristle 4 may comprise one or more hooks or barbs 41 at the tip of the bristle 4. It is noted that in any of the embodiments disclosed herein, one or more of the flexible bristles of the venous ablation system may be provided with such one or more hooks or barbs 40, 41 disposed along one or more of: the length of the bristles 4, and / or at the tips of the bristles 4. The hooks or barbs 40, 41 may be attached to the flexible bristles 4 by adhesive or welding. The hook or barb 41 at the tip of the bristle 4 may be unitary with the bristle 4 and the bristle 4 may be a shape memory material (such as nitinol) which is shape-set to include a hook or barb 41 shape at its tip. Accordingly, when deployed, the flexible bristle 4 expands to its pre-deformed shape including the hook or barb 41. The provision of one or more hooks or barbs 40, 41 may increase the damage provided to the vessel wall by the bristle device. It is noted that the hooks or barbs 40, 41 need not be made of an electrically conductive material. For example, hooks or barbs 40, 41 may be attached by welding, adhesive or similar to a bristle.

[0056] Fig. 2 shows a schematic view of a bristle portion 2 of a venous ablation system in an unconstrained configuration according to one or more embodiments. For example, the bristle portion 2 shown in Fig. 2 may be provided in the venous ablation system described with reference to Figs. 1 A and IB. In the embodiment shown in Fig. 2, the bristle portion 2 comprises a core 3 comprising a twisted wire portion 3a, wherein the plurality of bristles 4 penetrate the core 3 and are clamped by the twisted wire portion 3a such that the bristles 4 are secured to the core 3. The bristles 4 may be additionally secured to the core 3 by, for example, adhesive or welding. The bristle portion 2 may comprise a first set of bristles 6a configured to extend proximally and a second set of bristles 6b configured to extend distally, the distal direction opposite to the proximal direction. In some embodiments, the bristles 4 extend in a single longitudinal direction in the deployed configuration (either distally or proximally, but not both). That is, in some embodiments, the bristle portion 2 of Fig. 2 may comprise only bristles 4 extending distally, or only bristles 4 extending proximally. The first and second sets 6a, 6b of bristles 4 may each be grouped into a single segment located away from the other sets of bristles, as illustrated in Fig. 2 (i.e., there may be provided a gap between the bristle segments which is larger than the gap between neighbouring bristles within a single segment). The venous ablation system may comprise more than two bristle segments, wherein each segment comprises only distally or proximally extending bristles 4.

[0057] The core 3 may be formed of an electrically conductive material, namely, the twisted wire portion 3a may be made of flexible twisted metal wire, for example, stainless steel or any other suitable conductive material. In some embodiments, the proximal portion of the venous ablation system may be electrically connected to the distal portion D and optionally the plurality of bristles via contact with the core 3 (the twisted wire portion 3a). In other embodiments, the twisted wire portion 3a may be any suitable non-conductive material and the proximal portion may be electrically connected to the distal portion D and optionally the bristles 4 by a separate conductive element extending alongside the core 3, such as conductive wire C shown in Fig. 1 A, or a conductive coating on the core 3 or a conductive mesh or sleeve surrounding the core 3. The separate conductive element may extend from a distal portion of the delivery portion 5 in embodiments where the delivery portion 5 is conductive. The separate conductive element may extend to the proximal portion of the venous ablation system in embodiments where the delivery portion 5 is non-conductive. In some embodiments, the diameter of the twisted wire portion 3a used may be 0.5mm or less, though other diameters are contemplated and possible. The twisted wire portion 3a is at least partially integral with the delivery portion 5 (Fig. 1A) of the bristle device 1. For example, the delivery portion 5 may comprise one or more of the wires forming the twisted wire portion 3a configured to extend through the delivery catheter 7 (Fig. 1A) from a proximal end to a distal end of the delivery catheter 7. The delivery portion 5 may also be formed of an electrically conductive material and the proximal portion connected to the bristles 5 via the delivery portion 5.

[0058] Figs. 3A and 3B show a method of manufacturing the bristle portion 2 described with reference to Fig. 2, using a twisted wire method. A plurality of flexible bristles 4 may be placed between two parallel wires 10a, 10b. The parallel wires 10a, 10b may be fixed at one end and twisted about each other at another end to form a twisted wire portion. Upon twisting, the wires 10a, 10b are formed into a helix causing the bristles 4 to translate from being parallel to being rotationally offset from one another about the twisted wire portion 3a, wherein the twisted wire portion 3a clamps the bristles 4. Variations in the bristle density can be achieved by varying the pitch of the twisted wire which clamps the bristles 4. Fig. 3B shows the bristle portion 2 formed after the wires 10a and 10b are twisted about each other. In the embodiment of Figs. 3A and 3B, the twisted wire portion 3a therefore comprises two wire portions 10a and 10b twisted about each other. In embodiments where the bristle portion 3 is electrically conductive, one or both of the wire portions 10a and 10b may be electrically conductive. That is, in some embodiments, one wire portion may be made of a non-conductive material and the other may be made of a conductive material. The delivery portion 5 (Fig. 1A) may comprise one or both of the wire portions 10a, 10b extendable from a proximal portion to a distal portion of a delivery catheter for delivering the bristle portion 2 to the bodily lumen. In the delivery portion 5, the wire portions 10a and 10b may also be twisted about one another, or they may extend in an untwisted manner (as the delivery portion 5 does not need to be twisted to clamp any bristles 4). It will be noted that the bristle portion 2 shown in Fig. 2 may be manufactured by other methods, for example by first forming a twisted wired portion 3a and second mounting and securing the bristles 4 to the twisted wire portion 3a.

[0059] Fig. 4 shows a cross-sectional schematic view of a bristle portion 2 of a venous ablation system in an unconstrained configuration according to one or more embodiments. For example, the bristle portion 2 shown in Fig. 4 may be provided in the bristle device 1 described with reference to Figs. 1A and IB. In the embodiment shown in Fig. 4, the core 3 of the bristle portion 2 comprises a tube having a tubular wall 211. The plurality of bristles 4 each penetrate the tube wall 211 so that the tube wall 211 secures the plurality of bristles 4 to the core 3. The plurality of bristles 4 extend at least radially outwardly from the core 3. The tube wall 211 may comprise a plurality of holes in the wall, with one or more of the plurality of bristles 4 penetrating each hole in the tube wall 211. The tube may be generally cylindrical. The tube may define a lumen along the longitudinal axis of the tube. The bristle portion 2 of Fig. 4 may comprise a first set of bristles 4 configured to extend proximally and a second set of bristles 4 configured to extend distally, the distal direction opposite to the proximal direction, in some embodiments, the bristles 4 extend in a single longitudinal direction in the deployed configuration (either distally or proximally, but not both). That is, in some embodiments, the bristle portion 2 of Fig. 4 may comprise only bristles 4 extending distally, or only bristles 4 extending proximally. The first and second sets of bristles 4 may each be grouped into a single segment located away from the other sets of bristles 4, as illustrated in Fig. 1A (i.e. there may be provided a gap between the bristle segments which is larger than the gap between neighbouring bristles within a single segment). With additional reference to Figs. 1A and IB, the bristle device 1 may comprise more than two bristle segments, wherein each segment comprises only distally or proximally extending bristles 4. The core 3 is at least partially integral with the delivery portion 5 of the bristle device 1. For example, the delivery portion 5 may comprise one or more of the tube wall 211 and the filler material which are configured to extend from a proximal end of a delivery catheter to a distal end of the delivery catheter.

[0060] In some embodiments, the core 3 may be electrically conductive. For example, the tube wall 211 may be made of a conductive material such that the tube wall 211 is electrically connected to one or more of the plurality of bristles 4 (when conductive) by contacting one or more of the bristles 4. In such embodiments, the distal portion may be electrically connected to the proximal portion of the venous ablation system via the core 3. In some embodiments, the delivery portion 5 may also be conductive (for example the tube wall 211 when conductive, and optionally the filler material 212 may also be the delivery portion 5 and extend all the way to the proximal portion of the venous ablation system) and the electrical connection to the distal portion and optionally bristles 4 is provided via both the delivery portion 5 and the core 3. In other embodiments, the delivery portion 5 may be non-conductive (for example only a non-conductive filler material 212 may be integral with the delivery portion 5 and extend all the way to the proximal portion of the venous ablation system), and the electrical connection to the distal portion D, and optionally the bristles, from the proximal portion of the venous ablation system may be provided via a separate conductive element extending alongside the delivery portion 5 from the proximal portion to the core 3.

[0061] As shown in Fig. 4, the plurality of flexible bristles 4 each penetrate through the tube wall

[0062] 211 such that a portion of each of the flexible bristles 4 is disposed within the lumen of the tube.

[0063] The tube wall 211 may have a plurality of holes therein (not shown) through which, for example, a single one or some of the plurality of flexible bristles 4 passes therethrough. The holes may each have substantially the same diameter as the flexible bristle 4 which passes therethrough.

[0064] In some embodiments, the tube wall 211 may define a hollow lumen. In other embodiments, the core 3 may further comprise filler material 212 disposed within the lumen of the tube. As shown in Figure 4, the filler material 212 may substantially fill the lumen of the tube. The filler material 212 may comprise or consist of: medical grade 2 part epoxy resin, polyurethane, nylon 12, Pebax 4033, liquid crystal polymer, polyether ether ketone, polycarbonate, neoprene, acrylate polymers or any combination thereof.

[0065] The filler material 212 disposed within the lumen of the tube may engage the portions of the flexible bristles 4 which are disposed within the lumen of the tube. The filler material

[0066] 212 may act to additionally secure the plurality of flexible bristles 4 to the core 3.

[0067] The filler material 212 may be an adhesive. In such embodiments, the filler material 212 may engage the flexible bristles 4 by adhering or bonding to the flexible bristles 4.

[0068] The filler material 212 may be a curable material or settable material, which is curable or settable upon heating, solvent flashing and / or irradiating. Upon curing or setting, the filler material 212 may harden so as to secure the flexible bristles 4 to the core 3. The filler material 212 may engage the flexible bristles 4 by mechanically anchoring the flexible bristles 4 to the core 3.

[0069] As one (or a sub-set) of the plurality of flexible bristles 4 passes through each hole in the tube wall 211, the flexible bristles 4 are attached to the core 3 individually or in a (small) sub-set. Accordingly, if the integrity of the attachment of one of the flexible bristles 4 becomes compromised, the integrity of the attachments of the other flexible bristles 4 may not be compromised. For example, if one of the plurality of flexible bristles 4 is dislodged from the core 3, the attachment of the remaining flexible bristles 4 may remain uncompromised, which is not the case when the majority of the attachment force for a particular bristle 4 is provided for by surrounding / neighbouring bristles 4 (for example in the embodiment shown in Fig. 2, where one bristle 4 becoming dislodged from the twisted wire 3a may reduce the clamping force on neighbouring bristles 4 by the twisted wire 3a, increasing the likelihood that a plurality of bristles 4 become dislodged).

[0070] The core 3 and flexible bristles 4 of the venous ablation system may be manufactured by creating, for example, by machining, a plurality of holes in the tube wall 211 of the tube. One of the plurality of flexible bristles 4 may be inserted through each of the plurality of holes in the tube wall 211 such that a portion of each of the flexible bristles 4 extends into the lumen of the tube and a free portion of each of the flexible bristles 4 extends radially outwardly from the tube wall 211.

[0071] The filler material 212 may be disposed in the lumen of the tube. The filler material 212 may be disposed in the lumen of the tube before or after inserting the flexible bristles 4.

[0072] In certain embodiments, the filler material 212 may be a curable or settable material such that after disposing the filler material 212 in the lumen of the tube, the filler material 212 is cured or set such that it hardens so as to secure the plurality of flexible bristles 4 to the core 3.

[0073] It is noted that the filler material 212 described with reference to Fig. 4 may be provided to any of the bristle portions 2 disclosed herein comprising a tube wall (for example the embodiments described in relation to Figs. 5 and 6).

[0074] The plurality of holes in the tube wall 211 may be arranged so as to arrange the flexible bristles 4 in a prescribed manner. For example, the plurality of holes may be oriented such that the flexible bristles 4 are distributed substantially evenly around the circumference of the core 3. Additionally, or alternatively, the plurality of holes may be arranged in spacedapart segments as disclosed above.

[0075] Optionally, one or more of the plurality of bristles 4 may comprise a thick portion 213 disposed in the lumen defined by the tubular wall 211, the thick portion 213 being thicker than the portion of the bristle 4 extending through the tubular wall 211. The thick portion 213 may further reduce the likelihood of a bristle 4 becoming dislodged from the tubular wall 211. A thick portion 213 may be provided on any of the bristles 4 in any of the embodiments disclosed herein (for example on any of the bristles 4 of the bristle portions 2 described with reference to Figs. 2 to 8).

[0076] The tube wall 211 described in relation to Figs. 4 to 6 may be made of any suitable material, such as a polymer, and in some embodiments may comprise or consist of a heat shrinkable material such as polyolefin, Pebax, FEP, PTFE, PF A, ETFE, PET, polyether ether ketone or any combination thereof.

[0077] Fig. 5 shows a schematic cross-sectional view of a bristle portion 2 of a venous ablation system in an unconstrained configuration according to one or more embodiments. For example, the bristle portion 2 shown in Fig. 5 may be provided in the venous ablation system described with reference to Figs. 1A and IB. In the embodiment shown in Fig. 5, the core 3 of the bristle portion 2 comprises a tube having a tubular wall 211. The plurality of bristles 4 each penetrate the tube wall 211 so that the tube wall 211 secures the plurality of bristles 4 to the core 3. The plurality of bristles 4 extend at least radially outwardly from the core 3. The tube wall 211 may comprise a plurality of holes in the wall, with one or more of the plurality of bristles 4 penetrating each hole in the tube wall 211. The tube may be generally cylindrical. The tube may define a lumen along the longitudinal axis of the tube. The bristle portion 2 of Fig. 5 may comprise a first set of bristles 4 configured to extend proximally and a second set of bristles 4 configured to extend distally, the distal direction opposite to the proximal direction. In some embodiments, the bristles 4 extend in a single longitudinal direction in the deployed configuration (either distally or proximally, but not both). That is, in some embodiments, the bristle portion 2 of Fig. 5 may comprise only bristles 4 extending distally, or only bristles 4 extending proximally. The first and second sets of bristles 4 may each be grouped into a single segment located away from the other sets of bristles 4, as illustrated in Fig. 1A (i.e., there may be provided a gap between the bristle segments which is larger than the gap between neighbouring bristles within a single segment). With additional reference to Figs. 1 A and IB, the venous ablation system may comprise more than two bristle segments, wherein each segment comprises only distally or proximally extending bristles 4. The core 3 is at least partially integral with the delivery portion 5 of the bristle device 1. For example, the delivery portion 5 may comprise one or more of the tube wall 211 and the filler material which are configured to extend from a proximal end of a delivery catheter to a distal end of the delivery catheter.

[0078] As in the case of some embodiments described with reference to Fig. 4, the core 3 described with reference to Fig. 5 may be electrically conductive. For example, the tube wall 211 may be made of a conductive material such that the tube wall 211 is electrically connected to one or more of the plurality of bristles 4 (when conductive) by contacting one or more of the bristles 4. In such embodiments, the distal portion may be electrically connected to the proximal portion of the venous ablation system via the core 3. In some embodiments, the delivery portion 5 may also be conductive (for example the tube wall 211, and optionally any filler material may also be the delivery portion 5 and extend all the way to the proximal portion of the venous ablation system) and the electrical connection to the distal portion D and optionally bristles 4 is provided via both the delivery portion 5 and the core 3. In other embodiments, the delivery portion 5 may be non-conductive (for example only non-conductive filler material inside the tube wall 211 may be integral with the delivery portion 5 and extend all the way to the proximal portion of the venous ablation system; or the tube wall 211 may be integral with the delivery portion 5 and non- conductive, with an embedded conductive material extending only along the core 3 part of the tube wall 211 and connected to the bristles 4), and the electrical connection to the distal portion and optionally the bristles from the proximal portion of the venous ablation system may be provided via a separate conductive element extending alongside the delivery portion 5 from the proximal portion to the core 3.

[0079] As shown in Fig. 5, the plurality of flexible bristles 4 each penetrate through the tube wall 211 such that a portion of each of the flexible bristles 4 is disposed within the lumen of the tube.

[0080] The tube wall 211 may have a plurality of holes therein (not shown) through which, for example, a single one or some of the plurality of flexible bristles 4 passes therethrough. The holes may each have substantially the same diameter as the flexible bristle 4 which passes therethrough.

[0081] In some embodiments, the tube wall 211 may define a hollow lumen. In other embodiments, the core 3 may further comprise filler material 212 disposed within the lumen of the tube, as described previously with reference to Fig. 4. As can be seen from Figure 5, each of the plurality of flexible bristles 4 penetrate through the tube wall 211. A free portion 321a of each of the plurality of flexible bristles 4 extends radially outwardly from the tube, and, in particular, the tube wall 211.

[0082] A clamped portion 321b of each of the plurality of flexible bristles 4 is clamped between two opposing sides of the tube wall 211. The opposing sides of the tube wall 211 provide a clamping force on each of the clamped portions 321b such that the flexible bristles 4 are secured to the core 3.

[0083] In the embodiment shown in Figure 5, the tube of the core 3 has a lumen 313 extending along substantially the entire length of the tube. In this embodiment, the lumen 313 is a continuous lumen in which the clamped portions 321b of the flexible bristles 4 are disposed within the lumen 313. The opposing sides of the tube wall 211 may not contact each other at regions between the clamped portions 321b such that a continuous lumen is defined.

[0084] One portion of the lumen 313 may not be in fluid communication with another portion of the lumen 313, for example, due to a clamped portion 321b entirely filling a section of the lumen 313.

[0085] In certain embodiments, the portions of the tube wall 211 between some or all of the clamped portions 321b may be configured such that the opposing sides of the tube wall 211 contact each other (not shown in Figure 5).

[0086] Optionally, the portions of the tube wall 211 of the tube between each of the clamped portions 321b may be configured such that the opposing sides of the tube wall 311 contact each other such that the tube may comprise a number of distinct, isolated lumens disposed along the length of the tube. The lumens of the tube may be substantially filled by the clamped portions 321b of the plurality of flexible bristles 4.

[0087] The core 3 and flexible bristles 4 of the bristle portion 2 shown in Fig. 5 may be manufactured by creating, for example, by machining, a plurality of holes in the tube wall 211 of the tube. One or some of the plurality of flexible bristles 4 may be inserted through each of the plurality of holes in the tube wall 211 such that a portion 321b of each of the flexible bristles 4 extends into the lumen 313 of the tube. The portions 321b of each of the flexible bristles 4 may be clamped between two opposing sides of the tube wall 211.

[0088] In this regard, at least portions of the tube may be shrunk, for example, heat shrunk or chemically shrunk, in a radial direction such that the portions 321b of each of the flexible bristles 4 are clamped between two opposing sides of the tube wall 211.

[0089] Additionally, or alternatively, at least portions of the tube may be compressed (e.g. mechanically compressed), for example, by crimping, in a radial direction such that the portions 321b of each of the flexible bristles 4 are clamped between two opposing sides of the tube wall 211.

[0090] One or more of the bristles of Fig. 5 may comprise a thick portion 213 as previously disclosed with reference to Fig. 4.

[0091] Fig. 6 shows a schematic cross-sectional view of a bristle portion 2 of a venous ablation system in an unconstrained configuration according to one or more embodiments. For example, the bristle portion 2 shown in Fig. 6 may be provided in the bristle device 1 described with reference to Figs. 1A and IB. In the embodiment shown in Fig. 6, the core 3 of the bristle portion 2 comprises a tube having a tubular wall 211. The plurality of bristles 4 each penetrate the tube wall 211 so that the tube wall 211 secures the plurality of bristles 4 to the core 3. The plurality of bristles 4 extend at least radially outwardly from the core 3. The tube wall 211 may comprise a plurality of holes in the wall, with one or more of the plurality of bristles 4 penetrating each hole in the tube wall 211. The tube may be generally cylindrical. The tube may define a lumen along the longitudinal axis of the tube. The bristle portion 2 of Fig. 6 may comprise a first set of bristles 4 configured to extend proximally and a second set of bristles 4 configured to extend distally, the distal direction opposite to the proximal direction. In some embodiments, the bristles 4 extend in a single longitudinal direction in the deployed configuration (either distally or proximally, but not both). That is, in some embodiments, the bristle portion of Fig. 6 may comprise only bristles 4 extending distally, or only bristles 4 extending proximally. The first and second sets of bristles 4 may each be grouped into a single segment located away from the other sets of bristles 4, as illustrated in Fig. 1A (i.e. there may be provided a gap between the bristle segments which is larger than the gap between neighbouring bristles within a single segment). With additional reference Figs. 1A and IB, the bristle device 1 may comprise more than two bristle segments, wherein each segment comprises only distally or proximally extending bristles. The core 3 is at least partially integral with the delivery portion 5 of the bristle device 1. For example, the delivery portion 5 may comprise one or more of the tube wall 211, the inner mandrel 414 and the filler material which are configured to extend from a proximal end of a delivery catheter to a distal end of the delivery catheter.

[0092] As in the case of some embodiments described with reference to Figs. 4 and 5, the core 3 described with reference to Fig. 6 may be electrically conductive. For example, the tube wall 211 may be made of a conductive material such that the tube wall 211 is electrically connected to one or more of the plurality of bristles 4 by contacting one or more of the bristles 4. Alternatively, or additionally, the inner mandrel 414 may be made of a conductive material such that the inner mandrel is electrically connected to the distal portion D, and optionally one or more of the plurality of bristles 4 by contacting one or more of the bristles 4. In such embodiments where the core 3 is conductive, the proximal portion may be electrically connected to the proximal portion of the venous ablation system via the core 3. In some embodiments, the delivery portion 5 may also be conductive (for example one or more of the tube wall 211 and / or the inner mandrel 414 may also be the delivery portion 5 and extend all the way to the proximal portion of the venous ablation system) and the electrical connection to the bristles 4 is provided via both the delivery portion 5 and the core 3. In other embodiments, the delivery portion 5 may be non- conductive (for example one of the tube wall 211 and the inner mandrel 414 may be made of a non-conductive material and may be integral with the delivery portion 5 and extend all the way to the proximal portion of the venous ablation system, and the other of the tube wall 211 and the inner mandrel 414 may be conductive and not be provided as part of the delivery portion 5), and the electrical connection to the distal portion D and optionally the bristles from the proximal portion of the venous ablation system may be provided via a separate conductive element extending alongside the delivery portion 5 from the proximal portion to the core 3.

[0093] As shown in Fig. 6, the plurality of flexible bristles 4 each penetrate through the tube wall 211 such that a portion of each of the flexible bristles 4 is disposed within the lumen of the tube.

[0094] The tube wall 211 may have a plurality of holes therein (not shown) through which, for example, a single one or some of the plurality of flexible bristles 4 passes therethrough. The holes may each have substantially the same diameter as the flexible bristle 4 which passes therethrough. As can be seen from Figure 6, each of the plurality of flexible bristles 4 penetrates through the tube wall 211. A free portion 421a of each of the plurality of flexible bristles 4 extends radially outwardly from the tube, and, in particular, the tube wall 211.

[0095] A clamped portion 421b of each of the plurality of flexible bristles 4 is clamped between an inner mandrel 414 disposed within the lumen of the tube and the tube wall 211.

[0096] The clamped portions 421b of each of the flexible bristles 4 may be disposed within an annulus 415 defined between the inner mandrel 414 and the tube wall 211.

[0097] The inner mandrel 414 may comprise or consist of, for example, any suitable polymer metal or resin.

[0098] The outer surface of the inner mandrel 414 and the inner surface of the tube wall 211 provide a clamping force on each of the clamped portions 421b such that the flexible bristles 4 are secured to the core 3.

[0099] The portions of the tube wall 211 between some or all of the clamped portions 421b may be configured such that the outer surface of the inner mandrel 414 and the inner surface of the tube wall 211 contact each other (not shown in Figure 6).

[0100] Optionally, the portions of the tube wall 211 between some or all of the clamped portions 421b may be configured such that the outer surface of the inner mandrel 414 and the inner surface of the tube wall 211 contact each other such that the core 3 defines a number of distinct, isolated annuluses disposed along the length of the tube. The annuluses of the core 3 may be substantially filled by the clamped portions 421b.

[0101] The annulus 415 or annuluses of the core 3 may be filled with any filler material disclosed herein, such as the filler material 212 of Figure 4.

[0102] The core 3 and flexible bristles 4 of the bristle device 1 may be manufactured by creating, for example, by machining, a plurality of holes in the tube wall 211 of the tube. One of the plurality of flexible bristles 4 may be inserted through each of the plurality of holes in the tube wall 211 such that a portion 421b of each of the flexible bristles 4 extends into the lumen of the tube. An inner mandrel 414 may be inserted into the lumen of the tube such that the portions 421b are clamped between the inner mandrel 414 and the tube wall 211. Optionally, the tube wall 211 of the tube may be shrunk or mechanically compressed and / or the inner mandrel 414 may be radially expanded once it has been inserted into the lumen of the tube.

[0103] One or more of the bristles of Fig. 6 may comprise a thick portion 213 as previously disclosed with reference to Fig. 4.

[0104] Fig. 7 shows a schematic cross-sectional view of a bristle portion 2 of a venous ablation system in an unconstrained configuration according to one or more embodiments. For example, the bristle portion 2 shown in Fig. 7 may be provided in the bristle device 1 described with reference to Figs. 1A and IB. In the embodiment shown in Fig. 7, the core

[0105] 3 of the bristle portion 2 comprises a volume of material 912. The plurality of bristles 4 are each partially disposed within the volume of material 912 such that the material 912 surrounds and secures the plurality of bristles 4. The plurality of bristles 4 extend at least radially outwardly from the core 3. The bristle portion 2 of Fig. 7 may comprise a first set of bristles 4 configured to extend proximally and a second set of bristles 4 configured to extend distally, the distal direction opposite to the proximal direction. In some embodiments, the bristles 4 extend in a single longitudinal direction in the deployed configuration (either distally or proximally, but not both). That is, in some embodiments, the bristle portion of Fig. 7 may comprise only bristles 4 extending distally, or only bristles

[0106] 4 extending proximally. The first and second sets of bristles 4 may each be grouped into a single segment located away from the other sets of bristles 4, as illustrated in Fig. 1A (i.e. there may be provided a gap between the bristle segments which is larger than the gap between neighbouring bristles within a single segment). Referring additionally to Figs. 1 A and IB, the bristle device 1 may comprise more than two bristle segments, wherein each segment comprises only distally or proximally extending bristles. The core 3 is at least partially integral with the delivery portion 5 of the bristle device 1. For example, the delivery portion 5 may comprise the material 912 which is configured to extend from a proximal end of a delivery catheter to a distal end of the delivery catheter.

[0107] As in the case of some embodiments described with reference to Figs. 4 to 6, the core 3 described with reference to Fig. 7 may be electrically conductive. For example, the volume of material 912 may be include a conductive material embedded in the material such as a conductive wire or mesh or cylinder, such that the core 3 is electrically connected to one or more of the plurality of bristles 4 (when conductive) by contacting one or more of the bristles 4 with the embedded conductive material. In such embodiments where the core 3 is conductive, the distal portion D may be electrically connected to the proximal portion of the venous ablation system via the core 3. In some embodiments, the delivery portion 5 may also be conductive (for example the conductive material such as the embedded conductive wire or mesh may also be the delivery portion 5 and extend all the way to the proximal portion of the venous ablation system) and the electrical connection to the distal portion D and optionally bristles 4 is provided via both the delivery portion 5 and the core 3. In other embodiments, the delivery portion 5 may be non-conductive (for example the material 912 may be non-conductive and integral with the delivery portion 5 and extend all the way to the proximal portion of the venous ablation system, and conductive material embedded in the material 912 may only be provided in the core 3 and not the delivery portion 5), and the electrical connection to the distal portion D and optionally the bristles from the proximal portion of the venous ablation system may be provided via a separate conductive element extending alongside the delivery portion 5 from the proximal portion to the core 3.

[0108] In the embodiment shown in Fig. 7, a free portion 921a of each of the plurality of flexible bristles 4 extends radially outwardly from the core 3.

[0109] The volume of material 912 may comprise or consist of any of the materials listed for the filler materials described herein.

[0110] The core 3 is formed from a material 912. A portion 921b of each of the flexible bristles 4 is disposed within a volume of the material 912 of the core 3. The material 912 surrounds the portion 921b and secures the portion 921b to the core 3.

[0111] As shown in Figure 7, the material 912 substantially entirely surrounds and contacts an end portion 921b of each of the flexible bristles 4. Specifically, the material 912 may contact substantially an entire transversely extending edge surface of each of the flexible bristles 4.

[0112] Referring to Figure 7, the volume of the material 912 is a bulk or homogenous volume of the core 3 formed from a continuous volume of the material 912.

[0113] The material 912 of the core 3 engages the portions 921b of the flexible bristles 4. The material 912 acts to secure the plurality of flexible bristles 4 to the core 3.

[0114] The material 912 may be an adhesive. In such embodiments, the material 912 may engage the portions 921b of the flexible bristles 4 by adhering or bonding to the portions 921b. The material 912 may be a curable material or settable material, which is curable or settable upon heating, solvent flashing and / or irradiating. Upon curing or setting, the material 912 may harden so as to secure the flexible bristles 4 to the core 3.

[0115] The material 912 may engage the portions 921b of the flexible bristles 4 to mechanically anchor the flexible bristles 4 to the core 3.

[0116] As one (or a sub-set) of the plurality of flexible bristles 4 passes into the material 912 of the core 3, the flexible bristles 4 are attached to the core 3 individually or in a (small) subset. Accordingly, if the integrity of the attachment of one of the flexible bristles 4 becomes compromised, the integrity of the attachments of the other flexible bristles 4 may not be compromised. For example, if one of the plurality of flexible bristles 4 is dislodged from the core 3, the attachment of the remaining flexible bristles 4 may remain uncompromised, which is not the case when the majority of the attachment force for a particular bristle 4 is provided for by surrounding / neighbouring bristles 4.

[0117] Furthermore, the material 912 may be chosen so as to influence the structural properties of the core 3, for example, flexibility.

[0118] The core 3 and flexible bristles 4 of the venous ablation system may be manufactured by providing a core 3 formed from a material 912 and providing a plurality of flexible bristles 4 such that a portion 921b of each of the flexible bristles 4 is disposed within a volume of the material 912.

[0119] For example, the portions 921b of the flexible bristles 4 may be inserted into the material 912. Thereafter, the material 912 may be cured or set such that the material 912 surrounds the portions 921b and secures the portions 921b to the core 3, for example, by the hardening and / or contraction of the material 912.

[0120] In certain embodiments, the core 3 may be formed by molding the material 912. For example, the portions 921b of the flexible bristles 4 may be inserted into a mold cavity defined by a mold. A material to be molded may be inserted into the mold cavity. The material may be allowed to set such that the material 912 surrounds and secures the flexible bristles 4. The mold may then be removed to leave the core 3 and flexible bristles 4 secured thereto. In certain embodiments, a mold is not required. For example, the material 912 may be shaped into the core 3. Thereafter, the plurality of flexible bristles 4 may be inserted into the shaped material 912 such that the portions 921b are disposed within a volume of the material 912. Thereafter, the material 912 may optionally be cured or set such that the material 912 surrounds the portions 921b and secures the portions 921b to the core 3, for example, by the hardening and / or contraction of the material 912.

[0121] One or more of the bristles of Fig. 7 may comprise a thick portion 213 as previously disclosed with reference to Fig. 4.

[0122] Fig. 8 shows a schematic cross-sectional view of a bristle portion 2 of a venous ablation system in an unconstrained configuration according to one or more embodiments. For example, the bristle portion 2 shown in Fig. 8 may be provided in the bristle device 1 described with reference to Figs. 1A and IB. In the embodiment shown in Fig. 8, the core 3 of the bristle portion 2 comprises a volume of material 1112. The plurality of bristles 4 are each partially disposed within the volume of material 1112 such that the material 1112 surrounds and secures the plurality of bristles 4. The plurality of bristles 4 extend at least radially outwardly from the core 3. The bristle portion 2 of Fig. 8 may comprise a first set of bristles 4 configured to extend proximally and a second set of bristles 4 configured to extend distally, the distal direction opposite to the proximal direction. In some embodiments, the bristles 4 extend in a single longitudinal direction in the deployed configuration (either distally or proximally, but not both). That is, in some embodiments, the bristle portion 2 of Fig. 8 may comprise only bristles 4 extending distally, or only bristles 4 extending proximally. The first and second sets of bristles 4 may each be grouped into a single segment located away from the other sets of bristles 4, as illustrated in Fig. 1A (i.e., there may be provided a gap between the bristle segments which is larger than the gap between neighbouring bristles within a single segment). Referring additionally to Figs. 1 A and IB, the bristle device 1 may comprise more than two bristle segments, wherein each segment comprises only distally or proximally extending bristles 4. The core 3 is at least partially integral with the delivery portion 5 of the bristle device 1. For example, the delivery portion 5 may comprise one or more of the material 1112 and structural member 1113 which are configured to extend from a proximal end of a delivery catheter to a distal end of the delivery catheter.

[0123] The embodiment shown in Fig. 8 is similar to the embodiment of Fig. 7 in that the venous ablation system has a core 3 formed from a material 1112, and where a portion of each of the flexible bristles 4 is disposed within a volume of the material 1112 and a free portion extends radially outwardly. The volume of material 1112 may comprise or consist of any of the materials listed for the filler materials described herein.

[0124] However, in the embodiment shown in Fig. 8, the core 3 further comprises a structural member 1113. The structural member 1113 may be disposed at least partially or entirely within the material 1112 of the core 3. The structural member 1113 may have a lower flexibility than the material 1112 which provides structural support to the core 3.

[0125] As in the case of some embodiments described with reference to Figs. 4 to 7, the core 3 described with reference to Fig. 8 may be electrically conductive. For example, the volume of material 912 may be include a conductive material embedded in the material such as a conductive wire or mesh or cylinder, or the structural member 1113 may be made of a conductive material such that the core 3 is electrically connected to the distal portion D, and optionally one or more of the plurality of bristles 4 by contacting one or more of the bristles 4 with the embedded conductive material or the structural member 1113 when conductive. In such embodiments where the core 3 is conductive, the distal portion D may be electrically connected to the proximal portion of the venous ablation system via the core 3. In some embodiments, the delivery portion 5 may also be conductive (for example the conductive material such as the conductive wire or mesh embedded in the material 1112, or the structural member 1113 when conductive, may also be the delivery portion 5 and extend all the way to the proximal portion of the venous ablation system) and the electrical connection to the distal portion D / bristles 4 is provided via both the delivery portion 5 and the core 3. In other embodiments, the delivery portion 5 may be non-conductive (for example the material 912 may be non-conductive and integral with the delivery portion 5 and extend all the way to the proximal portion of the venous ablation system, and the conductive material embedded in the material 912 or the structural member 1113 when conductive, may only be provided in the core 3 and not the delivery portion 5), and the electrical connection to the distal portion D and optionally the bristles from the proximal portion of the venous ablation system may be provided via a separate conductive element extending alongside the delivery portion 5 from the proximal portion to the core 3.

[0126] The structural member 1113 may extend longitudinally along the length of the core 3. The structural member 1113 may be elongated or rod-shaped.

[0127] The structural member 1113 may be disposed within the material 1112 before the material 1112 is cured or set so as to secure the structural member 1113 within the material 1112 of the core. Alternatively, the structural member 1113 may be disposed within the material 1112 by inserting it into the material 112 after it has been cured or set, for example, by boring a hole within the material 1112 using the structural member 1113 itself and / or another device, such as a drill.

[0128] It is noted that in Figs. 4 to 8, an end of the flexible bristles 4 terminates within the core 3. However, some or all of the flexible bristles 4 of the embodiments described with reference to Figs. 4 to 8 may extend through the core 3 such that both ends of the flexible bristles are exterior to the core 3. The means and methods described in relation to Figs. 4 to 8 are equally applicable to such embodiments.

[0129] For example, Fig. 4 shows a bristle 4a penetrating through the tube wall 211 at two locations (i.e. a first location and a second location). Both of the ends of the flexible bristle 4a are disposed outside the core 3. Both ends extend radially outwardly from the core 3, and, in particular, the tube wall 211.

[0130] The above-noted first location and second location may be chosen in various manners.

[0131] In this regard, reference is made to bristle 4a which shows the first and second locations on substantially opposite sides of the circumference of the tube.

[0132] In other embodiments, the first and second locations may be, for example, in the same quarter of the circumference of the core 3. In other embodiments, the first and second locations are in the same half, third, fifth or sixth of the circumference of the core 3. For example, the first and second locations for bristle 4b are not diametrically opposite one another so that the bristle 4b is curved within the core 3.

[0133] It will be understood from the above-described embodiments that in any of the embodiments, the proximal portion may be electrically connected to the distal portion D, and optionally one or more of the conductive bristles (when provided) via one or more of the delivery portion 5 and the core 3 (i.e., that the electrical energy is configured to pass from the proximal portion of the system, and through one or more of the delivery portion 5 and core 3), when one or both of the delivery portion 5 and core 3 are conductive. In other embodiments, the electrical energy may bypass either or both of the delivery portion 5 or core 3 if either or both are non-conductive, by the use of a separate conductive element such as one or more conductive wires, meshes or coatings on the delivery portion 5 or core 3. Any of the venous ablation systems disclosed herein, including those disclosed in the accompanying figured and those disclosed in the appended claims, may generally be manufactured by the following process: forming a bristle portion at a distal portion of the venous ablation system by forming a plurality of resiliently flexible bristles on a core, such that the plurality of bristles extend at least radially outwardly from the core, the bristles having a collapsed delivery configuration and an expanded deployed configuration in which the bristles are configured to contact the vessel wall; wherein the core is at least partially integral with a delivery portion configured to deliver the bristle portion through a delivery catheter; the method comprising electrically connecting the distal portion to a proximal portion of the venous ablation system, the proximal portion configured to electrically connect to an electrical source.

[0134] In some embodiments, at least some of the bristles are electrically conductive and the method comprises electrically connecting the proximal portion to the said electrically conductive bristles.

[0135] In some embodiments, the step of electrically connecting the distal portion to a proximal portion of the venous ablation system comprises electrically connecting the proximal portion to the distal portion in a bipolar arrangement, such that the proximal portion is electrically connected to a first part of the distal portion by a first electrical connection, and the electrically connecting the proximal portion to a second part of the distal portion by a second electrical connection, the first and second electrical connections electrically isolated from one another

[0136] In some embodiments where the core and delivery portion are electrically conductive and the method comprises electrically connecting the proximal portion to electrically conductive bristles, the step of electrically connecting of the said bristles to a proximal portion may be the same step as forming the plurality of resiliently flexible bristles on the core.

[0137] In some embodiments the core may be formed of an electrically conductive material and the distal portion may include the core. In embodiments where the method comprises electrically connecting the proximal portion to electrically conductive bristles, the step of electrically connecting the plurality of bristles to the proximal portion may include the step of electrically connecting the plurality of bristles to the core (for example by physically contacting the plurality of bristles with the core). In other embodiments the core may be made of a non-conductive material and the plurality of bristles may be electrically connected to the proximal portion by a separate conductive element.

[0138] In some embodiments the delivery portion may be formed of an electrically conductive material and the step of electrically connecting the distal portion to the proximal portion may include electrically connecting the distal portion to the delivery portion. In embodiments where the delivery portion and core are integrally formed of a conductive material and the method comprises electrically connecting the proximal portion to electrically conductive bristles, this step may be the same step as forming the plurality of bristles on the core. In other embodiments, this step may include connecting the delivery portion to the distal portion via a separate conducting element such as one or more conducting wires.

[0139] In some embodiments the plurality of bristles may be formed on the core by penetrating the plurality of bristles through the core and securing the plurality of bristles to the core

[0140] In any of the embodiments described with reference to Fig. 2, the venous ablation system may be manufactured as described with reference to Figs. 3A and 3B.

[0141] In any of the embodiments wherein the core comprises a tube having a tube wall, the steps of penetrating and securing the bristles to the core may comprises penetrating the plurality of flexible bristles through a plurality of holes in the tube wall (e.g. tube wall 211). The plurality of flexible bristles may be secured to the tube wall by one or more of: mechanically compressing the tube; melting a portion of the tube when the bristles penetrate the tube wall; and shrinking the tube wall chemically or by heating the tube wall.

[0142] In any of the embodiments described wherein the core comprises a tube having a tube wall, the step of securing the bristles to the core may comprise clamping the plurality of flexible bristles between opposing sides of the tube wall (e.g. tube wall 211).

[0143] In any of the embodiments wherein the core comprises a tube comprising a tube wall, the step of securing the bristles to the core may comprise clamping the plurality of flexible bristles between an inner surface of the tubular wall (e.g. tube wall 211) and an outer surface of a mandrel (e.g. mandrel 414) disposed in a lumen of the tubular wall. In any of the embodiments described wherein the core comprises a tube comprising tube wall, the method of manufacture may comprise providing a filler material (e.g. filler material 212) within a lumen of the tube to secure the bristles in the tube. The method may comprise curing or setting the filler material.

[0144] In any of the embodiments described wherein the core comprises a volume of material (e.g. material 912 or 1112), the steps of providing and securing the bristles to the core may comprise partially disposing each of the plurality of bristles within the volume of material such that the material surrounds and secures the plurality of bristles. Optionally the method further may further comprise providing a structural member disposed at least partially within the volume of material. The bristles may be secured to the volume of material by one or more of: adhering or bonding the material to the plurality of bristles; mechanically anchoring the bristles to the material; and curing or setting the material.

[0145] Any of the venous ablation systems disclosed herein may be used in a method of closing a blood vessel of a patient. In the method, a delivery catheter may be inserted into the vasculature of the patient. A distal portion of the delivery catheter may be positioned at a target site in the blood vessel using any suitable technique. For example, a guidewire may be navigated to the target site in the blood vessel and the delivery catheter may be translated over the guidewire to reach the blood vessel. A bristle device of a venous ablation system according to any of the embodiments disclosed herein may be delivered to the distal portion of the delivery catheter, for example by pushing the delivery portion through the delivery catheter, and deployed from the delivery catheter so that the flexible bristles contact the vessel wall (for example as shown in Fig. IB). The bristle device may be deployed by pinning the bristle device and moving the delivery catheter proximally, or by pinning the delivery catheter and moving the bristle device distally. The bristle device may be translated to denude the vessel wall (for example by translating the venous ablation system distally and proximally or rotating the system one or multiple times as indicated by the arrow A in Fig. IB). Alternatively, or additionally, to translating the bristle device, the method may comprise applying electrical energy, for example RF energy, to the distal portion, for example by an RF generator or other electrical source electrically connected to the distal portion. The venous ablation system and delivery catheter may subsequently be removed from the patient. The bristle device may be repositioned inside the delivery catheter before the venous ablation system and delivery catheter are removed. In some embodiments, where at least some of the bristles are electrically conductive, electrical energy may be delivered directly to the vessel wall via the electrically conductive bristles.

[0146] In the methods disclosed herein, the order of presentation of the method steps do not denote a chronological order unless a subsequent step requires a previous step to be performed in order to enact the subsequent step.

[0147] All of the above are fully within the scope of the present disclosure, and are considered to form the basis for alternative embodiments in which one or more combinations of the above-described features are applied, without limitation to the specific combinations disclosed above.

[0148] In light of this, there will be many alternatives which implement the teaching of the present disclosure. It is expected that one skilled in the art will be able to modify and adapt the above disclosure to suit its own circumstances and requirements within the scope of the present disclosure, while retaining some or all technical effects of the same, either disclosed or derivable from the above, in light of his common general knowledge in this art. All such equivalents, modifications or adaptions fall within the scope of the present disclosure.

Claims

CLAIMS1. A venous ablation system comprising a bristle device, the bristle device comprising: a distal portion comprising a bristle portion, the bristle portion comprising a core and a plurality of resiliently flexible bristles extending at least radially outwardly from the core, the bristles having a collapsed delivery configuration and an expanded deployed configuration in which the bristles are configured to contact the vessel wall; and a delivery portion configured to deliver the bristle portion through a delivery catheter, the delivery portion at least partially integral with the core; the bristle device comprising a proximal portion electrically connected to the distal portion, the proximal portion configured to electrically connect to an electrical source.

2. The venous ablation system according to claim 1, wherein at least some of the bristles are electrically conductive and the proximal portion is electrically connected to the said electrically conductive bristles.

3. The venous ablation system according to claim 1 or claim 2, wherein at least some of the bristles are electrically insulated.

4. The venous ablation system according to any preceding claim, wherein the proximal portion is electrically connected to the distal portion in a bipolar arrangement, such that the proximal portion is electrically connected to a first part of the distal portion by a first electrical connection, and the proximal portion is electrically connected to a second part of the distal portion by a second electrical connection, the first and second electrical connections electrically isolated from one another.

5. The venous ablation system according to claim 4, wherein the first part comprises a proximal set of electrically conductive bristles and the second part comprises a distal set of electrically conductive bristles distal to the proximal set.

6. The venous ablation system according to any preceding claim, further comprising the electrical source.

7. The venous ablation system according to claim 6, wherein the electrical source is an RF generator configured to electrically connect to the proximal portion and to supply radiofrequency energy to the distal portion.

8. The venous ablation system according to claim, wherein the RF generator is configured to supply radiofrequency energy having a power of at least 0.01W and / or less than 100W.

9. The venous ablation device of any preceding claim, wherein the core is formed of an electrically conductive material and the proximal portion is electrically connected to the distal portion via the core.

10. The venous ablation device of any preceding claim, wherein the delivery portion is formed of an electrically conductive material and the proximal portion is electrically connected to the distal portion via the delivery portion.

11. The venous ablation system according to any preceding claim, wherein the plurality of bristles penetrate through the core such that the core secures the bristles.

12. The venous ablation device of claim 11, wherein the core comprises a twisted wire portion, the plurality of bristles clamped by the twisted wire portion.

13. The venous ablation device of claim 11, wherein the core comprises a tubular wall, and the plurality of bristles each penetrate the tubular wall so that the tubular wall secures the plurality of bristles to the core.

14. The venous ablation device of claim 13, wherein the core further comprises a filler material disposed within a lumen defined by the tubular wall, the filler material surrounding and securing portions of the flexible bristles which are disposed within the lumen.

15. The venous ablation device of claim 13 or 14, wherein the plurality of bristles are clamped between two opposing sides of the tubular wall.

16. The venous ablation device of claim 13 or 14, wherein the core further comprises a mandrel disposed in a lumen of the tubular wall, and each of the plurality of bristlesare clamped between an outer surface of the mandrel and an inner surface of the tubular wall.

17. The venous ablation device of claim 11, wherein the core comprises a volume of material and the plurality of bristles are each partially disposed within the volume of material such that the material surrounds and secures the plurality of bristles.

18. The venous ablation device of claim 17, wherein the core comprises a structural member disposed at least partially within the volume of material, the structural member having a lower flexibility than the material.

19. The venous ablation device of any preceding claim, wherein the plurality of bristles comprise a first set of bristles and a second set of bristles, the first set of bristles configured to extend in a proximal direction in the expanded deployed configuration and the second set of bristles configured to extend in a distal direction opposite to the proximal direction in the expanded deployed configuration.

20. The venous ablation device of any preceding claim, wherein each of the plurality of bristles comprises a thick portion, the thick portion being thicker than a portion of the bristle extending through the core.

21. The venous ablation device of any preceding claim, wherein at least some of the plurality of bristles comprise barbs or hooks disposed along the length of the bristles and / or at the tips of the bristles.

22. The venous ablation device of any preceding claim, further comprising one or more radiopaque markers.

23. A method of manufacturing a venous ablation system, comprising: forming a bristle portion at a distal portion of the venous ablation system by forming a plurality of resiliently flexible bristles on a core, such that the plurality of bristles extend at least radially outwardly from the core, the bristles having a collapsed delivery configuration and an expanded deployed configuration in which the bristles are configured to contact the vessel wall; wherein the core is at least partially integral with a delivery portion configured to deliver the bristle portion through a delivery catheter;the method comprising electrically connecting the distal portion to a proximal portion of the venous ablation system, the proximal portion configured to electrically connect to an electrical source.

24. The method of claim 23 wherein at least some of the bristles are electrically conductive and the method comprises electrically connecting the proximal portion to the said electrically conductive bristles.

25. The method of claim 23 or 24, wherein the step of electrically connecting the distal portion to a proximal portion of the venous ablation system comprises electrically connecting the proximal portion to the distal portion in a bipolar arrangement, such that the proximal portion is electrically connected to a first part of the distal portion by a first electrical connection, and electrically connecting the proximal portion to a second part of the distal portion by a second electrical connection, the first and second electrical connections electrically isolated from one another.

26. The method of any of claims 23 to 25, wherein the core is formed of an electrically conductive material and the distal portion includes the core.

27. The method of claim 23 to 26, wherein the delivery portion is formed of an electrically conductive material and the step of electrically connecting the distal portion to the proximal portion includes electrically connecting the distal portion to the delivery portion.

28. The method of any of claims 23 to 27, wherein the plurality of bristles are formed on the core by penetrating the plurality of bristles through the core and securing the plurality of bristles to the core.

29. The method of claim 28, wherein the core is a twisted wire portion and the steps of penetrating and securing the bristles to the core comprise: placing the plurality of flexible bristles between two wire elements; and twisting the two wire elements to form the twisted wire portion, the plurality of bristles clamped between the twisted wire portion.

30. The method of claim 28, wherein the core comprises a tube having a tubular wall and the steps of penetrating and securing the bristles to the core comprises:penetrating the plurality of flexible bristles through a plurality of holes in the tubular wall.

31. The method of claim 30, wherein the step of securing the bristles to the core comprises: clamping the plurality of flexible bristles between opposing sides of the tubular wall; or clamping the plurality of flexible bristles between an inner surface of the tubular wall and an outer surface of a mandrel disposed in a lumen of the tubular wall.

32. The method of claim 30 or 31, wherein the plurality of flexible bristles are secured to the tube wall by one or more of: mechanically compressing the tube; melting a portion of the tube when the bristles penetrate the tube wall; shrinking the tube wall chemically or by heating the tube wall.

33. The method of any of claims 30 to 32, further comprising providing a filler material within a lumen of the tube to secure the bristles in the tube.

34. The method of claim 28, wherein the core comprises a volume of material and the steps of penetrating and securing the bristles to the core comprises partially disposing each of the plurality of bristles within the volume of material such that the material surrounds and secures the plurality of bristles,35. The method of claim 34, wherein the method further comprises providing a structural member disposed at least partially within the volume of material.

36. The method of claim 34 or 35, wherein the step of securing the bristles to the core comprises one or more of the following: adhering or bonding the material to the plurality of bristles; mechanically anchoring the bristles to the material; curing or setting the material.

37. A method of closing a blood vessel of a patient, comprising the steps of: inserting a delivery catheter into the vasculature of the patient;positioning a distal portion of the delivery catheter at a target site in the blood vessel; delivering a bristle device of a venous ablation system according to any of claims 1 to 22 to the distal portion of the delivery catheter; deploying the bristle device from the delivery catheter so that the flexible bristles contact the vessel wall; and at least one of the following: translating the bristle device to denude the vessel wall; and / or delivering electrical energy to the distal portion.

38. The method of claim 37, comprising the step of delivering electrical energy to the distal portion, wherein the electrical energy is delivered to the vessel wall via plurality of the bristles.

39. The method of claim 37 or claim 38, wherein the electrical energy is radiofrequency energy.

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