Patent Description:
Embolisation devices may be deployed in the vasculature at a particular location by a medical practitioner so as to promote blood clot formation and ultimately occlude the blood vessel. Typically, an embolisation device is pushed through a guide catheter using a delivery wire until a point of deployment is reached. Once the device reaches the required point of deployment, the device is deployed from the guide catheter in a distal direction, detached from the delivery wire, and the delivery wire and delivery catheter are removed.

It is important that the embolisation device does not migrate within the vasculature once deployed, as this could cause serious adverse effects. Likewise, it is important that the constituent components of the embolisation device do not break, detach or become dislodged from the embolisation device as these could also migrate within the vasculature, causing similar adverse effects.

Accordingly, there is a need for embolisation devices with a reduced risk of migration.

There is also a need for embolisation devices to have a lesser longitudinal extent such that they are able to be deployed in a wider variety of vasculatures.

<CIT> discloses an occlusion device for a vascular or biological lumen including a plurality of coiling members held together at both the proximal and distal ends by retaining features. A restraining loop holds coiling members together at a point along a length of the coiling members.

<CIT> discloses a vascular filter including a hub and a basket portion. The filter is formed from a plurality of strands of a biocompatible material such as a polymer or a super-elastic metal alloy. The strands are intertwined to form the hub. The strands are then secured by forming a knot such as a crown knot or a splice. The free ends of the strands form a basket portion of the filter.

According to a first aspect, there is provided an embolisation device for promoting clot formation in a bodily lumen, the embolisation device having a collapsed delivery configuration and an expanded deployed configuration, the embolisation device comprising a plurality of flexible bristles, wherein at least one of the plurality of bristles comprises a twisted portion, the at least one twisted portion securing the plurality of bristles to one another, and wherein the plurality of bristles extend at least radially outwardly from the at least one twisted portion. The one or more twisting portions may inhibit the individual bristles from becoming detached from the embolisation device. The twisting portions may negate the need for a separate securing element for securing the bristles together, such as a stem, and reduce the longitudinal extent of the embolisation device, allowing the device to be deployed in smaller or shorter vasculatures.

The embolisation device of the first aspect further comprises a core body, wherein the at least one twisted portion of the bristles are located within the core body such that the core body surrounds and secures the at least one twisted portion. The core body may further inhibit the bristles from becoming detached from the embolisation device.

The core body of the embolisation devices disclosed herein may mechanically anchor the plurality of flexible bristles.

The core body may adhere or bond to the plurality of flexible bristles.

The core body may be a curable material or settable material, and may be curable or settable upon heating, solvent flashing and/or irradiating.

The core body may be cured or set such that the core body surrounds and secures the portion of the flexible bristle.

The core body may be a polymer, and, optionally, a nylon. The core body may be a resin. The core body may be a metal and/or an alloy.

According to a second aspect, there is provided an embolisation system comprising an embolisation device of the first aspect, further comprising an interconnecting module attached to the embolisation device at the core. The interconnecting module may be configured to connect to a delivery element. The interconnecting module may be configured to connect to a bristle segment comprising a second plurality of bristles. The bristle segment may comprise a plurality of bristles secured in the same manner as the first aspect, or may comprise a plurality of bristles extending at least radially outwardly from a stem.

The embolisation system may further comprise a radiopaque marker attached to the core.

According to a third aspect, there is provided an embolisation device for promoting clot formation in a bodily lumen, the embolisation device having a collapsed delivery configuration and an expanded deployed configuration, the embolisation device comprising a plurality of bristle segments, each segment comprising a plurality of flexible bristles, wherein, for at least one of the bristle segments: at least one of the plurality of bristles comprises a twisted portion, the at least one twisted portion securing the plurality of bristles in the segment to one another, and wherein the plurality of bristles extend at least radially outwardly from the at least one twisted portion. The embolisation device of the third aspect further comprises a core body, wherein the at least one twisted portion of the bristles are located within the core body such that the core body surrounds and secures the at least one twisted portion.

According to a fourth aspect, there is provided method of manufacturing an embolisation device for promoting clot formation in a lumen and having a collapsed delivery configuration and an expanded deployed configuration, the method comprising: providing a plurality of flexible bristles; and twisting at least one bristle of the plurality of bristles to form at least one twisted portion, the at least one twisted portion securing the plurality of bristles to one another such that the bristles extend at least radially outwardly from the at least one twisted portion. The method comprises providing a core body, wherein the at least one twisted portion of the bristles are located within the core body such that the core body surrounds and secures the at least one twisted portion.

For a better understanding of the present disclosure, and to show how the same may be carried into effect, reference will be made, by way of example only, to the following schematic drawings, in which:.

Throughout this disclosure the term 'embolisation device' may refer to a device which may be permanently or semi-permanently implanted in a bodily lumen. Accordingly, the 'embolisation device' may be configured to be disposed within the bodily lumen for a period of time, such as a number of days, or disposed in the lumen indefinitely. To this end, the 'embolisation device' may be configured to be selectively detached from a delivery element so that it may be implanted in the bodily lumen in isolation.

Throughout this disclosure the term 'bodily lumen' may refer to the inside space within a tubular structure of the human or animal body. The 'bodily lumen' may be, for example, an artery or vein.

Throughout this disclosure the term '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.

Throughout this disclosure the term 'to anchor' may refer to partly or fully securing an element in a position.

Throughout this disclosure, the term 'stem' may refer to an elongate element which extends longitudinally along the length of the embolisation device to act as a backbone for the device, and has a significantly smaller radial extent than the further elements of the embolisation device (for example, the plurality of flexible bristles). A stem may extend along substantially the whole longitudinal extent of the plurality of flexible bristles (e.g. when the embolisation device is in an unrestrained configuration, collapsed delivery configuration and/or expanded deployed configuration). The stem may extend along substantially the whole length of the embolisation device.

Throughout this disclosure, the term 'core body' may refer to any body suitable for surrounding and securing a portion of a flexible bristle which extends through the core body.

In any of the examples described herein, the term 'bristle' may refer to an elongate strand of material formed substantially a single piece. The 'bristle' may be a resilient bristle. The resilient bristle may be biased towards a particular curvature.

Throughout this disclosure, the term 'radially outwardly' does not exclude the element additionally extending in the longitudinal direction of the device. For example, the plurality of flexible bristles may extend radially outwardly and longitudinally from the core body or longitudinal axis of the embolisation device.

Through this disclosure, the term 'radial extent' may refer to a radial size in a particular direction radially outwardly from the centre of the core body or twisted portion of the embolisation device. For example, the embolisation device has a lower radial extent in the collapsed delivery configuration than in the expanded deployed configuration.

Throughout this disclosure, the term 'surround' may refer to when a first element contacts a second element about substantially an entire circumference of the second element.

Throughout this disclosure, the term 'mechanically anchor' refers to the anchoring of an element substantially by mechanical forces caused by the macroscopic properties of the anchoring element, rather than intermolecular forces and/or chemical bonds between the anchoring element and the anchored element which are responsible for adhering/bonding.

Throughout this disclosure, the term "bristle segment" may refer to a group of bristles wherein the spacing between adjacent bristles is less than a predetermined distance. When two bristle segments are "spaced apart", the spacing between the bristle segments (i.e. the spacing between the most distal bristle of the first segment and the most proximal bristle of the second segment) is greater than the spacing between adjacent bristles within at least one of the bristle segments.

The plurality of flexible bristles may have a collapsed configuration in the collapsed delivery configuration. The plurality of flexible bristles may have an expanded configuration in the expanded deployed configuration. The plurality of bristles may extend radially outwardly from the stem in a plurality of radial directions about the stem.

In the expanded configuration, the plurality of flexible bristles may be configured to anchor the device in the bodily lumen. The plurality of flexible bristles may be configured to provide substantially all of the anchoring force for the embolisation device in the bodily lumen.

In the expanded configuration, the plurality of flexible bristles may be configured to contact the bodily lumen.

The collapsed delivery configuration is adopted when the device is positioned inside the delivery catheter. More particularly, in the collapsed delivery configuration, the plurality of flexible bristles extending outwardly from the stem have a radial extent which is less than the radial extent of the bristles in the expanded deployed configuration of the element.

The bristles may be made of a flexible or resiliently deformable material such as stainless steel, Elgiloy or Nitinol. Other suitable materials may also be used, such as any suitable polymer or any other shape memory metal or metal alloy.

The diameter of an individual flexible bristle may range from <NUM> (<NUM> inches) to <NUM> (<NUM> inches). For example, the diameter of an individual flexible bristle may be <NUM> (<NUM> inches), <NUM> (<NUM> inches) or <NUM> (<NUM> inches). The average radial diameter of the radial profile formed by the expanded flexible bristles may range from <NUM> to <NUM>.

A flow restrictor may be a membrane made from thin film Nitinol, thin film PTFE, a thin film elastomer such as polyurethane, a polymer or any other type of suitable biocompatible material. The membrane may be made of any self-expanding material. The membrane may have a thickness of <NUM> to <NUM> and a radial diameter of <NUM> to <NUM>. For example, the diameter of the membrane may be <NUM>, <NUM> or <NUM>. Furthermore, the membrane may be non-permeable or semi-permeable.

<FIG> schematically depicts an embolisation device <NUM>. The embolisation device <NUM> is configured for deployment in a bodily lumen so as to promote clot formation therein. The embolisation device <NUM> in <FIG> is shown in an unconstrained configuration.

The embolisation device <NUM> comprises a stem <NUM>, a plurality of flexible bristles <NUM> in bristle segments 120a, 120b and a flow restricting membrane <NUM>.

The embolisation device <NUM> is guided through a delivery catheter using a delivery element <NUM> (depicted schematically in <FIG>). The delivery element may be releasably connected to a proximal end of the embolisation device, for example by a threaded connection. Once the embolisation device has been delivered to the target site within the bodily lumen, then the embolisation device is moved distally relative to the delivery catheter such that the bristles expand to the expanded deployed configuration and engage the walls of the bodily lumen to anchor the device to the lumen. The embolisation device <NUM> is then released from the delivery element and the delivery element and delivery catheter are withdrawn.

The stem <NUM> of the embolisation device <NUM> may be made of a twisted wire or wires, wherein the twisted wire holds the bristles <NUM> in the embolisation device. <FIG> shows close up cross-section view of the embolisation device <NUM>, taken along the line A-A in <FIG>. The bristle <NUM> shown in <FIG> extends out of the plane of the figure and is shown in cross section. As can be seen by <FIG>, the twisted wire of the stem <NUM> abuts or clamps the bristle <NUM> at two radially opposite locations on the surface of the bristle. The friction provided by this contact between the stem <NUM> and the bristle <NUM> holds the bristle <NUM> in place. However, in the illustrated example, the twisted wire of the stem <NUM> does not surround the part of the bristle <NUM> that extends between the twisted wires. In particular, the twisted wire only contacts the bristle <NUM> at two points, rather than about the circumference of the part of the bristle <NUM> between the twisted wires. This is indicated by the gaps <NUM> in <FIG>. In other words, the frictional force applied by the twisted wires to the bristle <NUM> are centred upon only two points on the surface of the bristle <NUM>. As a result, there remains a risk that the bristle <NUM> detaches or dislodges from the twisted wire and from the embolisation device <NUM>. Furthermore, it has been observed that once a single bristle becomes dislodged from the embolisation device <NUM>, the force required to dislodge further bristles is greatly reduced. As such, the risk of further bristles becoming dislodged increases.

The stem <NUM> may also increase the longitudinal dimension of the embolisation device, meaning that some vasculatures may not be suitable for the embolisation device <NUM> as it is too long.

<FIG> schematically depicts a side view of an embolisation device <NUM> in a collapsed delivery configuration inside a delivery catheter C.

As can be seen from <FIG>, in the collapsed delivery configuration of the embolisation device <NUM>, the plurality of flexible bristles 120a, 120b have been collapsed into a collapsed configuration.

As also can be seen from <FIG>, in the collapsed delivery configuration of the embolisation device <NUM>, the flow restricting membrane <NUM> has been collapsed into a collapsed configuration.

In <FIG>, both the proximal bristle segment 120a and the distal bristle segment 120b point proximally. However, as will be evident to the person skilled in the art, any arrangement in this regard is possible. In particular, the proximal bristle segment 120a and the distal bristle segment 120b may point distally. The proximal bristle segment 120a may point proximally and the distal bristle segment 120b may point distally. The proximal bristle segment 120a may point distally and the distal bristle segment 120b may point proximally.

<FIG> schematically depicts the embolisation device <NUM> in an expanded deployed configuration in a bodily lumen L. The embolisation device <NUM> may be pushed through the delivery catheter C by delivery element <NUM> (for example a delivery wire) until it reaches the distal end of the catheter C. Once the end of the catheter is in the target position in a bodily lumen L, the device <NUM> is moved distally relative to the catheter C by the delivery element <NUM>, with the catheter C held in place. The device <NUM> is then disposed within the bodily lumen L in the expanded deployed configuration by removing the delivery catheter C whilst inserted in the bodily lumen L such that the embolisation device <NUM> is allowed to expand in the bodily lumen L. The delivery element <NUM> is then removed from the device <NUM>, for example by twisting the delivery element to cause the two to detach.

The expanded deployed configuration of the embolisation device <NUM> has a greater radial extent than the collapsed delivery configuration shown in <FIG>. In the expanded deployed configuration shown in <FIG>, the plurality of flexible bristles 120a, 120b and the flow restricting membrane <NUM> contact the bodily lumen L so as to anchor the embolisation device <NUM> within the bodily lumen L. The anchoring force provided by the plurality of flexible bristles 120a, 120b and the flow restricting membrane <NUM> may be sufficient to resist migration of the embolisation device <NUM> in the bodily lumen L.

In the expanded deployed configuration shown in <FIG>, the embolisation device <NUM> may occlude the bodily lumen L and promote clot formation therein.

<FIG> schematically depicts another embolisation device <NUM> according to the present disclosure. Again, the embolisation device <NUM> is configured for deployment in a bodily lumen so as to promote clot formation therein. The embolisation device <NUM> in <FIG> is shown in an unconstrained configuration.

The embolisation device <NUM> comprises a plurality of bristles <NUM>. At least one of the plurality of bristles <NUM> comprises a twisted portion <NUM>. The twisted portion secures the plurality of bristles to one another, such that the plurality of bristles are secured together by the twisted portion <NUM>. For example, the at least one twisted portion may be threaded about the other bristles in a manner that is sufficient to secure them together. It is noted that the twisted portion <NUM> is simplified for illustration purposes. It will be apparent to the skilled person that there are many different possible configurations of the at least one twisted portion that can be used to secure the plurality of bristles <NUM> together, such as one or more knots or loops or any combination thereof. In other examples, a plurality of bristles <NUM> may have a twisted portion to ensure that the bristles <NUM> are securely fastened together. In some examples, the plurality of bristles may be plaited or braided to one another. As the bristles <NUM> are secured to one another by the twisted portion <NUM>, the longitudinal extent of the embolisation device <NUM> is reduced as a separate securing element is not required. For example, a longitudinally extending stem upon which the bristles are secured may not be required.

The embolisation device <NUM> may further comprise a flow restrictor, such as a flow restricting membrane <NUM> (for example a disc-shaped membrane), located longitudinally within the bristles. The flow restrictor may be mounted on the device by manipulating a portion of bristles such that they extend longitudinally in a low radial profile (for example using a bristle manipulator), mounting the flow restrictor over the portion of bristles onto the device (i.e. passing them through a central hole of the membrane), and releasing the bristles such that the flow restrictor is positioned longitudinally within the bristles and secured in place by the proximal and distal neighbouring bristles, as shown in <FIG>. Alternatively, the membrane <NUM> may be a mesh membrane and at least some of the bristles pass through holes in the mesh proximal to the centre of the mesh membrane such that those bristles secure the membrane <NUM> to the device <NUM>.

As in the case of the embolisation device <NUM> shown in <FIG>, the embolisation device <NUM> has a collapsed delivery configuration in which it may be placed within a delivery catheter, analogous to the configuration shown in <FIG>. The embolisation device <NUM> may be pushed through a delivery catheter by a delivery element (e.g. as shown in <FIG>, for example by a push wire or delivery wire), which may be releasably connected to the embolisation device by an interconnecting module <NUM> comprising a releasable connecting mechanism, or which may be a pushing element. Once the embolisation device is at the desired location within a bodily lumen, the embolisation device <NUM> and delivery catheter are moved relative to one another and the embolisation device <NUM> delivered to the bodily lumen. For example, the catheter is retracted whilst the delivery element is held in place. The delivery element is then released from the embolisation device <NUM> (if necessary) and removed from the bodily lumen with the delivery catheter.

The connecting mechanism may be any suitable connecting mechanism. For example, the mechanism may comprise a male/female threaded connector connected to the embolisation device, and a female/male threaded connector connected to the delivery element. The delivery element may then be rotated to release the embolisation device <NUM> from the delivery element. It will be apparent to the skilled person that any other releasable connecting mechanism would be suitable. The interconnecting module <NUM> comprising the connecting mechanism may be connected to the embolisation device <NUM> by adhesive or welding.

In the expanded deployed configuration, the bristles <NUM> of the embolisation device <NUM> extend outwardly to engage the bodily lumen to anchor the device to the bodily lumen, analogous to the configuration shown in <FIG>.

As in the case of the embolisation device shown in <FIG>, the embolisation device <NUM> comprises a plurality of bristles <NUM>. At least one of the plurality of bristles <NUM> comprises a twisted portion <NUM>. The twisted portion secures the plurality of bristles to one another, such that the plurality of bristles are secured together by the twisted portion <NUM>, as described above in relation to <FIG>. It will again be apparent that there are many different possible configurations of the twisted portion that can be used to secure the plurality of bristles <NUM> together. In other examples, a plurality of bristles <NUM> may each have a twisted portion to ensure that the bristles <NUM> are securely fastened together. In some examples, the plurality of bristles may be plaited or braided to one another.

In addition to the twisted portion <NUM>, the embolisation device <NUM> of <FIG> comprises a core body <NUM> surrounding and securing the twisted portion <NUM>. The twisted portion <NUM> and the core body <NUM> both work to inhibit the flexible bristles <NUM> from become dislodged. The bristles comprising the twisted portions are especially inhibited from being dislodged (e.g. extracted) from the core body <NUM> due to the presence of the twisted portion. In embodiments where the bristles are plaited or braided together, the plaits inhibit each of the bristles from becoming dislodged.

The core body <NUM> of <FIG> may also be made of any suitable material for surrounding and securing the portions of the flexible bristles extending through the core body. For example, the core body <NUM> may be made of a material that adheres or bonds to the plurality of flexible bristles. Additionally and alternatively, the cored body <NUM> may be configured such that the core body <NUM> mechanically anchors the flexible bristles <NUM>.

For example, the core body <NUM> may be a curable material or settable material, for example which is curable or settable upon heating, solvent flashing and/or irradiating. The core body <NUM> may be a polymer, a nylon, a resin or a metal or metal alloy.

The device <NUM> may also comprise a flow restrictor corresponding to the previous embodiments. The flow restrictor may comprise a membrane <NUM>, for example a disc-shaped membrane, and may be mounted on the device by manipulating a portion of the bristles to extend longitudinally in a low radial profile, passing them through a central hole of the membrane, and releasing the bristles so that the membrane is secured longitudinally between the bristles. The flow restrictor may also extend partially through the core body <NUM> to further secure the membrane <NUM> to the device. For example, the membrane <NUM> may be mounted to the device before the core body <NUM> is added to the device during manufacture.

The embolisation device <NUM> of <FIG> again has a collapsed delivery configuration in which it may be placed within a delivery catheter C. The embolisation device <NUM> may be pushed through a delivery catheter by a delivery element, which may be releasably connected to the embolisation device by a connecting mechanism. Once the embolisation device is at the desired location within a bodily lumen, the embolisation device <NUM> and the delivery catheter are moved relative to one another and the embolisation device is delivered to the bodily lumen. For example, delivery element is held in place and the catheter is retracted. The delivery element is then released from the embolisation device <NUM> and removed from the bodily lumen with the delivery catheter.

The connecting mechanism may be any suitable connecting mechanism such as a screw mechanism, and may be comprised in an interconnecting module <NUM> connected to the device as discussed in further detail in the previously-described examples. For example, the module <NUM> may be secured to the device <NUM> by the core body <NUM> or by adhesive or welding to the core body <NUM>.

<FIG> schematically depicts another embolisation device, according to the present disclosure, in an unconstrained configuration. The embolisation device of <FIG> comprises two bristle segments, each comprising a plurality of bristles extending generally (i.e. at least) radially outwardly from a core body <NUM> and from a twisted portion <NUM>, respectively. The two bristle segments are connected to one another. The bristle segments may be directly connected to one another, for example via adhesive or welding, or spaced apart via an interconnecting module <NUM>, which may be attached to the respective bristle segments by, for example, welding or adhesive. The interconnecting module <NUM> may be made of any biocompatible material, and may be a polymer, nylon, a resin, a metal or an alloy. The interconnecting module may be a unitary body. A flow restrictor may be mounted between the bristle segments (e.g. on the interconnecting module <NUM>) or between the bristles of a bristle segment. As before, the embolisation device shown in <FIG> has a collapsed delivery configuration in which it may be placed in a delivery catheter, and may be deployed to a bodily lumen in the same manner as with the previously described examples (i.e. an interconnecting module comprising a releasable connecting mechanism may be attached to a proximal end of the device for releasably connecting the device to a delivery element).

It will be apparent to the skilled person that the interconnecting module <NUM> may be configured to connect any two of the embolisation devices disclosed herein, and an embolisation device of any number of spaced apart bristle segments may be provided by using a plurality of interconnecting modules <NUM> to connect them.

<FIG> schematically depicts a side view of an embolisation device <NUM> in a collapsed delivery configuration inside a delivery catheter C. The embolisation device <NUM> may be any of the embodiments disclosed here, for example the embodiments described with reference to <FIG>, <FIG> or <FIG>.

As can be seen from <FIG>, in the collapsed delivery configuration of the embolisation device <NUM>, the plurality of flexible bristles and (optionally) the flow restrictor of the device have been collapsed into a collapsed configuration. It is noted, as with the example shown in <FIG>, that the flexible bristles of each segment of the device <NUM> may point in either the proximal or the distal direction when in the collapsed configuration.

<FIG> schematically depicts the embolisation device <NUM> in an expanded deployed configuration in a bodily lumen L. The embolisation device <NUM> may be pushed through the delivery catheter C by delivery element <NUM> (for example a delivery wire) until it reaches the distal end of the catheter C. Once the end of the catheter is in the target position in a bodily lumen L, the device <NUM> is moved distally relative to the catheter C by the delivery element <NUM>, with the catheter C held in place. The device <NUM> is then disposed within the bodily lumen L in the expanded deployed configuration by removing the delivery catheter C whilst inserted in the bodily lumen L such that the embolisation device <NUM> is allowed to expand in the bodily lumen L. The delivery element <NUM> is then removed from the device <NUM>, for example by twisting the delivery element to cause the two to detach when the delivery element <NUM> detaches from an interconnecting module <NUM> of the device <NUM>. Alternatively, the device may not comprise an interconnecting module <NUM> and the delivery element <NUM> may be a push wire. Accordingly, the device <NUM> is then delivered by simply pushing the device <NUM> out of the catheter C.

The expanded deployed configuration of the embolisation device <NUM> has a greater radial extent than the collapsed delivery configuration shown in <FIG>. In the expanded deployed configuration shown in <FIG>, the plurality of flexible bristles and (optionally) the flow restricting membrane contact the bodily lumen L so as to anchor the embolisation device <NUM> within the bodily lumen L. The anchoring force provided by the plurality of flexible bristles and the flow restricting membrane may be sufficient to resist migration of the embolisation device <NUM> in the bodily lumen L.

An embolisation device comprising one or more twisted portions to secure the bristles, such as that illustrated in <FIG> and <FIG>, may be manufactured by:.

The method may comprise forming a plurality of twisted portion. For example, the method may comprise plaiting or braiding the bristles together at a central portion.

The bristles may additionally be shape-set once the twisted portions have been formed in order to securely fasten the bristles in place.

It will be appreciated by the skilled person that there are a multitude of possible manners in which to twist the at least one bristle. The number of twisted portions and the manner in which the bristle is twisted to secure the bristles will depend on various factors such as the number of bristles to be secured, the mechanical properties of the bristles and the diameter and length of the bristles.

A core body is additionally provided after the twisted portions are formed. For example, the one or more twisted portions may be inserted into a mould and a material for the core body may be added to the mould and set. Alternatively, the core body material could be added directly to the twisted portions, for example in liquid phase, and set to create the core body.

Claim 1:
An embolisation device (<NUM>, <NUM>) for promoting clot formation in a bodily lumen (L), the embolisation device (<NUM>, <NUM>) having a collapsed delivery configuration and an expanded deployed configuration, the embolisation device (<NUM>, <NUM>) comprising a plurality of flexible bristles (<NUM>), wherein at least one of the plurality of bristles (<NUM>) comprises a twisted portion (<NUM>), the at least one twisted portion (<NUM>) securing the plurality of bristles (<NUM>) to one another, and wherein the plurality of bristles (<NUM>) extend at least radially outwardly from the at least one twisted portion (<NUM>);
characterised in that
the embolisation device (<NUM>, <NUM>) further comprises a core body (<NUM>), wherein the at least one twisted portion (<NUM>) of the bristles (<NUM>) are located within the core body (<NUM>) such that the core body (<NUM>) surrounds and secures the at least one twisted portion (<NUM>).