Patent Description:
Embolisation devices for occluding a bodily lumen are disclosed in <CIT> and <CIT>.

Such embolisation devices may have a core and a plurality of flexible bristles which extend radially outwardly from the core. The embolisation device may also be provided with a membrane having a contracted delivery configuration and an expanded deployed configuration. The contracted delivery configuration is such that the embolisation device may be loaded into a delivery catheter allowing the embolisation device to be translated through the delivery catheter for delivery to a bodily lumen.

However, during translation through a delivery catheter, the membrane of the embolisation device may deform, for example, by folding from the initial contracted delivery configuration due to forces acting on the membrane during translation. Such forces may be exerted by the bristles of the embolisation device and/or the inner wall of the delivery catheter.

Furthermore, due to this deformation of the membrane during translation through the delivery catheter, expansion of the membrane from the contracted delivery configuration to the expanded deployed configuration upon delivery to a bodily lumen may not occur in a reliable manner. In such cases, the membrane may not expand completely to its intended expanded deployed configuration or may exhibit undulations in its surface. In addition to this, the bristles neighbouring the membrane may also not expand in a reliable manner upon delivery. For example, the bristles may clump together such that they are not evenly distributed around the circumference of the device. These issues result in less occlusion of the bodily lumen, and, due to the uneven distribution of the bristles, also result in lower anchoring forces.

Accordingly, there is a need for an improved embolisation device in which deformation of the membrane during translation through the delivery catheter is minimised whilst also allowing reliable expansion of the membrane and adjacent bristles to their expanded deployed configurations.

<CIT> discloses a membrane implant, said implant being implantable by endovascular methods into the vessel to be treated, wherein the membrane implant consists of an expandable stent and a membrane connected with the stent, with said membrane covering the meshes of the stent at least in a central region, wherein said membrane is provided in the form of a non-woven fabric comprising plastic fibrils, and the membrane forms an integral bond with the stent and, at <NUM> least partially, is of porous design.

<CIT> discloses implantable medical devices for the occlusion of a bodily lumen, cavity, vessel, or organ, as well as methods for manufacturing such occlusion devices, and methods for treating a subject using the occlusion devices. The devices generally include a wire having shape memory properties and a flexible membranous material disposed about the wire. Some embodiments include a lateral fringe on the membranous material. Some embodiments include a fluid capture cup affixed to the wire.

In a first aspect, there is provided a laminate membrane for an implant, comprising: an inner layer having an inner layer thickness; a first covering layer disposed on one side of the inner layer, the first covering layer having a first covering layer thickness; and a second covering layer disposed on another side of the inner layer, the second covering layer having a second covering layer thickness; wherein the inner layer comprises, or consists of, a polyurethane and polytetrafluoroethylene composite, and, wherein at least one of the first covering layer and the second covering layer comprises, or consists of, a hydrophilic material. The laminate membrane comprises a through-hole extending through the inner layer, first covering layer and second covering layer, for passing through of a core of the embolisation device.

In a second aspect, there is provided an embolisation device according to claim <NUM>.

In a third aspect, there is provided a method of manufacturing a laminate membrane according to claim <NUM>.

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

<FIG> shows a cross-section of a laminate membrane <NUM> according to an embodiment of the present disclosure. The laminate membrane <NUM> comprises an inner layer <NUM> having an inner layer thickness X, a first covering layer <NUM> having a first covering layer thickness Y and a second covering layer <NUM> having a second covering layer thickness Z. The first covering layer <NUM> is disposed on one side of the inner layer <NUM>. The second covering layer <NUM> is disposed on another side of the inner layer <NUM>. In this embodiment, the first covering layer <NUM> is disposed on one side of the inner layer <NUM>, and the second covering layer <NUM> is disposed on the opposite side of the inner layer <NUM>.

As shown in <FIG>, laminate membrane <NUM> and each of the inner layer <NUM>, first covering layer <NUM> and second covering layer <NUM> may be disc-shaped. The laminate membrane <NUM> has a through-hole H which may be a central through-hole.

First covering layer <NUM> may entirely cover one side of the inner layer <NUM>. Second covering layer <NUM> may entirely cover the other side of the inner layer <NUM>.

The laminate membrane <NUM> may be configured to have a contracted delivery configuration and an expanded deployed configuration. In the contracted delivery configuration (see <FIG>), the laminate membrane <NUM> forms a conical shape with a smaller radial extent than in the expanded deployed configuration (see <FIG>).

The inner layer <NUM> provides the backbone of the laminate membrane <NUM> which provides structural properties of the laminate membrane <NUM> such as stiffness and elasticity. In this embodiment, the first covering layer <NUM> and the second covering layer <NUM> are outermost surface layers of the laminate membrane <NUM>. The first covering layer <NUM> and the second covering layer <NUM> dictate the properties of the outer surface of the laminate membrane <NUM> such as the frictional properties and surface energy.

The first covering layer <NUM> and the second covering layer <NUM> may each be made from a lower friction material than the material from which the inner layer <NUM> is made.

The skilled person will be aware of many different ways of determining whether a material is a lower friction material than another material. For example, the materials to be compared may be formed so as to have flat surfaces, and the surface energy, surface roughness, or static coefficient of friction (relative to itself or another common surface) of these surfaces may be measured, as would be understood by the skilled person. The flat surfaces of each of the materials being tested may be formed by the same process (e.g. each formed by electrospinning, extrusion, film casting, dip casting, spin casting, spray deposition or vapour deposition).

In other words, at least one of the first covering layer <NUM> and the second covering layer <NUM> are made of a material which exhibit a lower surface roughness or static coefficient of friction (measured relative to itself or another common surface) than the material from which the inner layer <NUM> is made of.

The stiffness of the inner layer <NUM> may be greater than the stiffness of each of the first covering layer <NUM> and the second covering layer <NUM>.

The elasticity of the first covering layer <NUM> and/or the second covering layer <NUM> may be higher than or equal to the elasticity of the inner layer <NUM>. In such cases, the laminate membrane <NUM> may allow for a contracted delivery configuration with a lower radial profile without risk of permanent deformation as the first covering layer <NUM> and/or the second covering layer <NUM>, which experience greater elongation during bending of the laminate membrane <NUM> than the inner layer <NUM>, are better able to stretch relative to the inner layer <NUM>.

Various materials may be used for the inner layer <NUM>, first covering layer <NUM> and the second covering layer <NUM>.

In some examples not falling under the scope of the appended claims, the inner layer <NUM> may consist of polyurethane (PU) and each of the first covering layer <NUM> and the second covering layer <NUM> may consist of polytetrafluoroethylene (PTFE). In this case, the inner layer <NUM> of PU provides high stiffness to the laminate membrane <NUM>, whereas the first covering layer <NUM> and the second covering layer <NUM> of PTFE result in the outer surface of the laminate membrane <NUM> having low friction. The high stiffness may allow the laminate membrane <NUM> to reliably transition from the contracted delivery configuration to the expanded deployed configuration, whilst the low friction surfaces may reduce deformation during translation.

In this embodiment, first covering layer thickness Y and second covering layer thickness Z are the same, and the first covering layer thickness Y and the second covering layer thickness Z are each smaller than the inner layer thickness X.

The inner layer thickness X may be between <NUM> to <NUM>, and the first covering layer thickness Y and the second covering layer thickness Z may be between <NUM> to <NUM>. In another embodiment, the inner layer thickness X may be between <NUM> to <NUM>, and the first covering layer thickness Y and the second covering layer thickness Z may be between <NUM> to <NUM>.

The laminate membrane <NUM> may be manufactured by providing the inner layer <NUM>, providing the first covering layer <NUM> on one side of the inner layer <NUM>, and providing a second covering layer <NUM> on another side of the inner layer <NUM>. Each of the inner layer <NUM>, first covering layer <NUM> and the second covering layer <NUM> may be deposited using electrospinning.

<FIG> shows a cross-section of a laminate membrane <NUM> according to another embodiment comprising an inner layer <NUM> having an inner layer thickness X', a first covering layer <NUM> having a first covering layer thickness Y' and a second covering layer <NUM> having a second covering layer thickness Z'. The first covering layer <NUM> is disposed on one side of the inner layer <NUM>. The second covering layer <NUM> is disposed on the opposite side of the inner layer <NUM>.

The inner layer thickness X' may be between <NUM> to <NUM>, and the first covering layer thickness Y' and the second covering layer thickness Z' may be between <NUM> to <NUM>. In another embodiment, the inner layer thickness X' may be between <NUM> to <NUM>, and the first covering layer thickness Y' and the second covering layer thickness Z' may be between <NUM> to <NUM>.

Laminate membrane <NUM> is similar to laminate membrane <NUM> shown in <FIG>, except that first covering layer <NUM> and second covering layer <NUM> also cover the outer edge surface of the inner layer <NUM>. In particular, first covering layer <NUM> and second covering layer <NUM> also cover the curved edge surface of the inner layer <NUM>. Hence, the first covering layer <NUM> and the second covering layer <NUM> together cover all external surfaces of the inner layer <NUM>.

<FIG> shows an embolisation device <NUM> according to an embodiment of the present disclosure. The embolisation device <NUM> has a longitudinally extending core <NUM> and a plurality of flexible bristles <NUM> extending outwardly from the core, the flexible bristles <NUM> are configured to have a contracted delivery configuration and an expanded deployed configuration in which the flexible bristles <NUM> extend generally radially outwardly from the core to anchor the device in a bodily lumen. The flexible bristles <NUM> may be configured to be resilient such that they are biased from their contracted delivery configuration to their expanded deployed configuration.

The embolisation device <NUM> also has a laminate membrane <NUM> disposed on the core <NUM>. The laminate membrane <NUM> may be any of the laminate membranes described herein. The laminate membrane <NUM> has a through-hole which allows the core <NUM> to pass through the laminate membrane <NUM>. The laminate membrane <NUM> is configured to occlude flow through the bodily lumen.

The laminate membrane <NUM> is positioned on the core <NUM> within a segment of flexible bristles <NUM>. Some flexible bristles 32a are disposed proximally adjacent to one side of the laminate membrane <NUM> and some flexible bristles 32b are disposed distally adjacent to the opposite side of the laminate membrane <NUM>.

<FIG> shows the embolization device <NUM> in its expanded deployed configuration in a bodily lumen <NUM>, where the flexible bristles <NUM> and the laminate membrane <NUM> are in their expanded deployed configurations. In this configuration, the laminate membrane <NUM> occludes flow through the bodily lumen <NUM>. The flexible bristles <NUM> anchor the embolisation device <NUM> in the bodily lumen <NUM>, preventing migration of the embolisation device <NUM>.

The orientation of the expanded laminate membrane <NUM> in its expanded deployed configuration and the orientation of the expanded flexible bristles <NUM> in the expanded deployed configuration is the same. For example, both the laminate membrane <NUM> and the adjacent flexible bristles <NUM> may be deployed pointing distally or proximally.

<FIG> shows the embolization device <NUM> in its contracted delivery configuration in a delivery catheter <NUM>, where the flexible bristles <NUM> and the laminate membrane <NUM> are in their contracted delivery configurations. When the flexible bristles <NUM> and the laminate membrane <NUM> are in their contracted delivery configurations, at least a portion of the laminate membrane <NUM> contacts the delivery catheter. In the contracted delivery configuration, the embolisation device <NUM> may be translated through the delivery catheter <NUM>.

The orientation of the collapsed laminate membrane <NUM> in its contracted delivery configuration and the orientation of the collapsed flexible bristles <NUM> in the contracted delivery configuration is the same. For example, both the laminate membrane <NUM> and the adjacent flexible bristles <NUM> may be collapsed pointing distally or proximally.

Using any of the laminate membranes as described herein may provide an embolisation device <NUM> in which deformation of the membrane <NUM> during translation through the delivery catheter <NUM> is minimised whilst also allowing reliable expansion of the membrane <NUM> and adjacent bristles <NUM> to their expanded deployed configurations.

Although the above explanation is considered to fully clarify how the present disclosure may be straight-forwardly put into effect by those skilled in the art, it is to be regarded as purely exemplary. In particular, there are a number of variations which are possible, as may be appreciated by those skilled in the art.

For example, even though the above laminate membranes are disc-shaped, they may be of any shape such as rectangular, square or cylindrical.

Further, even though the above laminate membranes are described in relation to an embolisation device with a core and a plurality of flexible bristles, laminates according to the present disclosure are also applicable to any type of embolisation device.

Specifically, according to an aspect of the present disclosure, there is provided an embolisation device, comprising: a laminate membrane as described herein.

In an embodiment, the laminate membrane is configured to have a contracted delivery configuration and an expanded deployed configuration. The embolisation device may comprise an embolisation coil. The laminate membrane may be disposed around at least part of the embolisation coil. At least a part of the laminate membrane may be disposed between adjacent turns in the embolisation coil.

Furthermore, even though the above laminate membranes are described in relation to embolisation devices, laminate membranes according to the present disclosure are also applicable to any type of medical implant, and, in particular, a medical implant with a contracted delivery configuration and an expanded deployed configuration, where the medical implant is configured to be delivered to a bodily lumen in the contracted delivery configuration. For example, the laminate membranes according to the present disclosure are particularly suited to expandable stents. Using the laminate membranes of the present disclosure may reduce deformation of the membrane during translation through the delivery catheter whilst also allowing reliable expansion of the membrane to its expanded deployed configuration.

Further, each of the inner layer, first covering layer and the second covering layer may be made from various materials. The inner layer is made from a composite of polyurethane and one or more other materials. In particular, the inner layer is made from a polyurethane and polytetrafluoroethylene composite. In some examples not falling under the scope of the appended claims, the inner layer may be made from a copolymer of <NUM>% 55D polyurethane and <NUM>% silicone, by weight. In other examples not falling under the scope of the appended claims, the inner layer <NUM> may comprise, or consist of, condensed PTFE or fluorinated ethylene propylene (FEP).

Each of the first covering layer and the second covering layer may be made from a composite of materials. The first covering layer and the second covering layer may be made from different materials from each other. At least on of the first covering layer and the second covering layer comprises or consists or a hydrophilic material. First covering layer may be made from: a hydrophobic material such as polytetrafluoroethylene and/or ultra-high molecular weight polyethylene; a hydrophilic material; and/or silicone. The second covering layer may be made from: a hydrophobic material such as polytetrafluoroethylene and/or ultra-high molecular weight polyethylene; a hydrophilic material; and/or silicone.

Further, the structural properties of the inner layer, first covering layer and the second covering layer may be varied from the above. In particular, the inner layer may have higher elastic recovery, tear-resistance and/or permeability than at least one of the first covering layer and the second covering layer. At least one of the first covering layer and the second covering layer may have lower surface energy than the inner layer.

In the above embodiments, the inner layer, the first covering layer and the second covering layer are each single layers. However, in alternative embodiments, the inner layer, the first covering layer and/or the second covering layer may each be formed of multiple sub-layers.

Further, the above laminate membranes may further comprise a tie-layer disposed between the inner layer and one or each of the fist covering layer and the second covering layer. Such a tie-layer may increase the adherence between the layers. As an example, such a tie-layer may be DuPont™ Bynel®. The tie-layers may be made from: modified ethylene vinyl acetate polymer; acid modified ethylene acrylate resin; anhydride modified ethylene acrylate resin; or anhydride-modified linear low-density polyethylene resin. Generally, the tie-layers may be made from ethylenes including acetates & acrylates thereof. <FIG> shows an exemplary embodiment of a laminate membrane <NUM> comprising tie-layers <NUM>, <NUM>. The laminate membrane <NUM> is similar to laminate membrane <NUM> in that in has an inner layer <NUM>, first covering layer <NUM> and second covering layer <NUM>. However, laminate membrane <NUM> has a first tie-layer <NUM> disposed between the inner layer <NUM> and the first covering layer <NUM>, and a second tie-layer <NUM> disposed between the inner layer <NUM> and the second covering layer <NUM>.

In some embodiments, the inner layer and the first covering layer and/or the second covering layer may be chemically or electrostatically adhered to each other.

Furthermore, even though the above manufacturing method uses an electrospinning process for forming each of the layers, various other manufacturing methods may be used. For example, the layers may be formed by electrospinning, extrusion, film casting, dip casting, spin casting, spray deposition or vapour deposition. Furthermore, different layers may be formed by different methods. For example, the inner layer may be formed from dip casting or spray casting. The first covering layer and the second covering layer may each be formed by electrospinnning onto the inner layer.

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.

Claim 1:
A membrane (<NUM>, <NUM>, <NUM>) for an embolisation device, comprising:
a though-hole (H) for passing through of a core of the embolisation device,
characterised in that
the membrane is a laminate membrane, and
the laminate membrane further comprises
an inner layer (<NUM>, <NUM>, <NUM>) having an inner layer thickness (x, x');
a first covering layer (<NUM>, <NUM>, <NUM>) disposed on one side of the inner layer, the first covering layer having a first covering layer thickness (y, y'); and
a second covering layer (<NUM>, <NUM>, <NUM>) disposed on another side of the inner layer, the second covering layer having a second covering layer thickness (z, z'); wherein the inner layer comprises, or consists of, a polyurethane and polytetrafluoroethylene composite, and, wherein at least one of the first covering layer and the second covering layer comprises, or consists of, a hydrophilic material wherein the through-hole (H) extends through the inner layer, first covering layer and second covering layer.