The invention relates to an embolic protection device according to the preamble of claim1which prevents undesirable macroscopic particles out of a blood stream from entering one or more branch vessels of a main blood vessel, such as the aortic arch. The invention also relates to a forming device for shaping the inventive embolic protection device, as well as a method for folding and unfolding the inventive embolic protection device by means of the forming device.

Cerebral embolism is a known complication in heart surgery and in interventional cardiology. Particles can be loosened by surgical or interventional operations. They can enter the blood stream and, in particular, trigger an embolism in the brain. If a cerebral embolism happens, it can cause a stroke or even death.

Embolic protection devices are known, for example, from the applicant's EP2859864.

It is an object of the present invention to provide an improved embolic protection device so that in a simple manner undesirable macroscopic particles from a blood stream are prevented from entering one or more branch vessels of a main blood vessel.

The inventive solution is achieved by the features the independent claims. Further advantageous developments of the invention are provided by the dependent claims.

According to a first aspect of the invention an embolic protection device for insertion into an aortic arch is provided, comprising a filter unit, a frame and a feed unit, wherein the filter unit is arranged at the frame. The frame provides a proximal area comprising a proximal shape, which is arranged in an inner area of the frame and is connected to the feed unit, wherein the proximal shape comprises a first part and a second part, wherein the second part is formed at one end of the first part.

The inner area of the frame comprises both the plane spanned by the frame as well as the area below or above this plane.

The inventive embolic protection device provides in an advantageous manner a device which is characterised by a spring mechanism created by the connection of the proximal shape and the feed unit, which provides that the embolic protection device is pressed on to the wall of the blood vessel in the aorta in the direction of the head vessels substantially in the distal area. Undesirable macroscopic particles are substantially deflected using the embolic protection device.

The proximal area is positioned in front of the ostium of the left subclavian artery by retracting the feed unit. Thus a stable position is achieved in the aortic arch. In an alternative positioning scenario, the embolic protection device can also be inserted via the right subclavian artery. In this case, the proximal area is positioned in front of the ostium of the brachiocephalic artery by retracting the feed unit.

The spring mechanism is formed in particular by the geometry of the proximal shape. Preferably, the first part of the proximal shape is arranged below the plane of the frame, in particular in the inner area of the frame. The first part is advantageously formed in the shape of an arch. The second part of the proximal shape is arranged preferably above the frame, in particular in the inner area of the frame. The second part is advantageously formed straight. Preferably, the first and the second part are at an angle to one another and/or to the plane of the frame. In other words, at least the first and/or the second part(s) may be arranged above or below the plane of the frame, wherein the angle between the first part and the plane of the frame differs from the angle between the second part and the plane of the frame, so that the first and the second part enclose an angle.

Using the feed unit, the proximal shape can be brought under tension, so that the spring effect is transmitted via the proximal shape to the entire frame of the embolic protection device. Due to this tension transmission, the distal area of the frame in particular folds up.

The frame of the embolic protection device extends over a two dimensional plane and changes in the proximal area into a proximal shape, which advantageously can protrude from this plane downwards or upwards. The proximal shape arranged inside the frame and connected with the feed unit creates the spring mechanism, which ensures that the frame with the filter unit can be secured over one or more blood vessels, so that they are protected or covered. When the filter unit is spread, radial forces take effect. The positioning of the embolic protection device is performed by the spring mechanism and by the feed unit. Furthermore, a haptic feedback is achieved when positioning the embolic protection device or a resistance is felt when retracting of the feed device so that, accordingly, the correct position of the embolic protection device can be checked. In particular, the head blood vessel by which the embolic protection device is introduced is also covered and protected.

Because of the geometry of the frame, in particular the proximal shape and/or the distal shape, the embolic protection device adapts itself flexibly to the anatomical conditions in the aortic arch regardless of the entry path and offers a complete coverage of all head blood vessels.

Advantageously, the first part and the second part of the proximal shape are arranged in the inner area of the frame. In particular, the connection point between proximal shape and feed unit is arranged in the inner area of the frame so that the coverage of the entry blood vessel is ensured. In other words, the proximal area of the frame or, respectively, of the filter unit covers the ostium of the entry blood vessel and extends far beyond it. At the same time, the proximal area of the frame or, respectively, of the filter unit is in contact with the aorta wall. In particular, therefore, this ensures coverage of the entry blood vessel when the embolic protection device is placed in the aortic arch.

The inventive embolic protection device, in particular the frame and the filter unit arranged on it, can be completely folded and unfolded. In the folded state, the embolic protection device is preferably dimensioned such that its diameter is substantially 1.4-2.2 mm, in particular 1.7-1.8 mm. The embolic protection device has three states: an unfolded state, in which the embolic protection device is in its basic form (basic state), a folded state, for example, in a catheter (folded state), and an unfolded state (placement state), when the embolic protection device is used as intended, such as in the aortic arch in the final position. The final position in the aortic arch is also called the placement position in the following.

The geometric form of the three states is different. During transportation and preparation for implantation, the embolic protection device is in its basic state, as shown, for example, in the figures. Due to mechanical reshaping, the basic state is converted into the folded state. The reversibly deformable material of the frame, for example, a superelastic nitinol wire, can be reshaped so that the embolic protection device can be pushed into a catheter. In doing so, the embolic protection device is extended along its direction, wherein, by folding up the distal shape and the proximal shape into an outer area of the frame, it changes into a straight or extended shape. The consequent change in length depends on the reduction in the width. In this case, the folded frame, i.e. the two sides of the frame outside the distal shape and/or proximal shape, are located from the tip to the end of the frame, that is, from the distal shape to the proximal shape, parallel to each other in the catheter. The specially attached filter unit is able to follow this mechanical deformation and is located in the intermediate space between catheter and wire. The frame made of nitinol provides a so-called shape memory effect.

In the placement position in the aortic arch, the geometry of the frame of the embolic protection device flexibly adapts to the aorta wall and lies in a slight arc, following the curvature of the aorta, in front of the head blood vessel outflows. When leaving the catheter, both the distal shape as well as the proximal shape folds back into their original shape, thus enabling an atraumatic positioning of the frame at the aorta wall. Due to the specific shape of the folded distal shape and proximal shape, transitions or corners with sharp edges are avoided. Radial forces generated by the shape memory effect of the frame, span the filter surface. Extra frame stability is achieved by the physiological conditions in the aorta since, due to the surface resistance of the filter, the blood flow additionally presses the frame of the embolic protection device into its placement position.

The material of the frame is preferably nitinol. The frame can be a wire, or a hollow wire in whose hollow space a platinum-/platinum-iridium-/tantalum wire is placed, wherein the hollow space is almost completely filled. Alternatively, the frame can be made from DFT wire, for example, from Fort Wayne Metals, or can be a wire with a firmly attached platinum/tantalum core. These examples for the material of the frame have the advantage that the frame is radiopaque.

The filter unit comprises a filter material which is selectively permeable so that, for example, undesirable macroscopic particles from the blood stream cannot enter into one or more branch vessels of a main blood vessel, such as the aortic arch. For example, the filter material comprises different materials, such as plastics or metallic materials such as nitinol. It is possible, depending on the material used, to weave, cast, laser-cut or to stamp the filter material. Preferably the filter material is a woven membrane made of polyamide. The filter material preferably has a pore size of 40-150 μm and an open porosity of 35-60%, by means of which it ensures, on the one hand, good protection from undesirable particles and, on the other hand, good porosity for blood. The filter material can have square or rectangular open surfaces. The thickness of the filter material is preferably 20-120 μm.

The feed unit is a tube made of wound stainless steel wire, but other materials can be chosen also. The feed unit is resistant to kinking and serves, when positioning the embolic protection device, to transmit torque and force. Advantageously, the length of the feed unit is 120-250 cm with a diameter of 1.5 mm and has a plastic coating externally (pebax coating, polyethylene (PE), polytetrafluorethylene (PTFE), polyamide (PA)).

The length of the embolic protection device is advantageously 50 to 100 mm. The width of the embolic protection device is advantageously 15 to 45 mm.

In a further development, the embolic protection device provides that the first part of the proximal shape is at a first angle to the plane of the frame and the second part is at a second angle to the first part of the proximal shape. Advantageously, the first and second parts of the proximal shape are aligned coaxially at the connecting point between first and second parts and form the spring mechanism by varying the sizes of the angles via the feed unit, so that the embolic protection device can be secured in the placement position in the aortic arch. The first part of the proximal shape is at an angle of about 25 to 50 degrees, preferably 30 degrees, downwards to the two-dimensional plane of the frame, measured from the first part to the plane. The first part is straight or arc-shaped and preferably has a length of 0.5 to 2.5 cm cm. The second part, preferably straight in shape, is formed at the end of the first part. The second part encloses a second angle of preferably 80 to 115 degrees with the first part, measured from the second part to the first part. If the second angle is measured to the two-dimensional plane of the frame, it is substantially 110 to 145 degrees, measured from the second part to the plane. Preferably, the second part is substantially 1-5 cm long. This geometric shape of the proximal shape ensures that the geometry of the proximal shape in the positioned state is such that it adapts to the anatomy.

Another advantageous further development provides that the proximal shape comprises two ends of the frame which extend parallel to each other in the inner area of the frame. This makes the frame more stable longitudinally as well as laterally. In further developments of the embolic protection device, the two ends are attached to the feed unit by means of an adhesive bond. The ends of the wire are not freely accessible therefore. Further developments are also possible in which the proximal shape comprises only one end of the frame wherein the second end of the frame is attached, for example, to the feed device.

In advantageous further developments, provision is made that the frame has a distal area which comprises a distal shape, which is arranged in an inner area of the frame. Advantageously, the tip of the distal shape is coated with atraumatic material (such as membrane material, polymer, rubber or resin adhesive) so that atraumatic protection is provided. Advantageously, this material can be formed as a nose in the shape of a droplet.

In another advantageous further development, the distal shape is characterised such that it provides a constriction towards the inside of the frame. The constriction serves as a connection place for the filter unit. It also serves as an aid to positioning in the aorta since it is provided with radiopaque markers and can be used advantageously as a means for displaying the alignment of the frame in the catheter. The distal shape arranged in the inner area of the frame serves, furthermore, in an advantageous manner as an aid to positioning when pushing the embolic protection device through a forming device into a catheter. In this process, the distal shape can be hooked on to or into the forming device and be folded in the direction opposite that of the original direction. In other words, the distal shape can be folded outwards, that is, into an area outside the inner area of the frame. The advantage of this is that, when pushing through a catheter, for example, the frame can be arranged space saving in the catheter. By folding the distal shape, torsional forces are transferred to the frame, which result in the folding back of the distal shape in the inner area of the frame when unfolding the embolic protection device in the aortic arch.

Advantageously the joint between frame and filter unit is an adhesive tunnel connection. The adhesive tunnel connection is made as an enveloping polymer shape around the frame. In other words, the adhesive envelopes the frame in the shape of a tube or cylinder. The polymer shape forms a so-called adhesive tunnel, in which the frame is arranged and can move relative to the latter. Advantageously, the joint between the adhesive tunnel and the filter unit can also be mechanically stable. By separating the filter unit from the frame, flexibility is created in the distal and proximal areas, which enables, or at least facilitates the folding of these areas when folding or unfolding the embolic protection device.

In another advantageous further development, provision is made that the filter unit is connected to the frame outside the proximal and/or distal area(s). This connection is mechanically stable, that is, with no relative movement between adhesive and frame. Advantageously the connection is formed as a flexible joint. For example, the joint can be a glue joint, a form fit, a weld or a sewn joint. The adhesive tunnel enables a stable and flexible connection to be made also or in particular during the folding or unfolding of the embolic protection device.

In a further advantageous further development, the filter unit in the distal area is connected with the frame substantially as far as the constriction. This prevents the filter unit from unintentionally folding down underneath the frame. The connection can be formed up to the start of the constriction.

In another advantageous further development, the filter unit in the proximal area is connected to the frame substantially up to the first part of the proximal shape. The connection can be made up to the start of the first part.

In another advantageous further development, the filter unit in the distal and proximal areas is connected flexibly to the frame. Therefore, this enables a relative movement to be made between frame and filter unit. This ensures that the frame in the proximal and distal areas is connected movably with the filter unit. In contrast, the frame in the remaining area is connected immovably to the filter unit.

Advantageously, this connection is an adhesive tunnel connection which is made as an enveloping polymer shape around the frame. For an adhesive tunnel connection, the frame is immersed in an adhesive. During drying of the adhesive, the adhesive is moved and forms a polymer shape on the filter unit (like a tube). Geometric changes of the embolic protection device, in particular of the frame, for example, when folding or unfolding the frame or, respectively, the filter unit, can be carried out easily, thus avoiding a delay or, in the most extreme case, damage to the embolic protection device.

Preferably the frame is connected to the filter unit with prestressing. For example, the slightly pressed frame can be connected to the filter unit in order to maintain a prestressing. The connecting of the filter material to the frame is preferably arranged such that the frame, both in the basic state as well as in the positioned state, applies a prestress to the filter unit.

Advantageously, the filter unit is glued to the frame from below. The result is that a smooth surface is created for the flow of blood.

In an advantageous further development, the edge of the filter unit is sealed before attachment to the frame to prevent changes in shape as it is being used, as well as effecting as atraumatic an interaction with the aorta wall as possible.

In another advantageous further development, provision is made that the filter unit protrudes over the frame. Preferably, the filter unit protrudes outside the proximal and/or distal area(s). The protrusion of the filter unit over the frame outside the distal or proximal areas is advantageously between 0.5 and 2.0 mm wide, so that a sealing lip is formed to the vessel wall when the frame is positioned in the placement state in the aortic arch. The sealing lip supports an atraumatic placement of the frame as well as the stability of its shape. Additionally, this sealing lip in the placement state closes against the aorta wall, thus preventing leakage, such as through a valve, around the sides of the embolic protection device.

Advantageously the protrusion is sealed, providing a smooth closure of the filter material. This also supports the atraumatic placement of the frame.

In another advantageous further development, provision is made that the filter unit in the proximal and/or distal area(s) of the frame is flipped over the frame from the lower side to the upper side. Thus the filter unit protrudes into the outer area of the frame. Due to the flipping or turning over/folding over of the filter unit over the proximal and/or distal area(s) of the frame, the attachment of the filter unit on the frame is improved, wherein the complete covering of all head blood vessels is ensured when the embolic protection device is positioned in the aortic arch. The filter unit is located in the proximal and/or distal area(s) as a double layer, thereby increasing the effectiveness of the filter.

In another advantageous further development, the filter unit in the distal and/or proximal area(s) is secured by means of a thread, yarn or wire to the distal shape or proximal shape. Additionally, this connection can be sealed to achieve a stable shape. Furthermore, due to the sealing, the connection in this area is atraumatic.

In an advantageous further development, the filter unit is secured to the distal shape by gluing. The gluing can be achieved by means of a resin adhesive. Due to the gluing, the frame has an atraumatic tip in the distal area, so if contact is made with the distal area with, for example, the aorta wall, it is protected from injuries.

Advantageously the filter unit is attached in the proximal area by means of a coil. The coil is made of stainless steel wire which wraps the ends of the frame preferably in the shape of a spiral. The coil serves to stabilise the connection between filter unit and feed unit. In addition, the coil shape supports the change in shape during of the folding and unfolding of the embolic protection device.

In order to improve the embolic protection device even further, it is provided in an advantageous further development that the filter unit is made of a fibre material wherein the fibres are aligned in such a way that they are at an angle of substantially 45 degrees with a longitudinal axis of the frame. The fibre material consists of a woven membrane which ensures that it has increased flexibility in the longitudinal and lateral directions of the frame. The longitudinal direction of the frame extends from the proximal to the distal area and is preferably the centre line of the frame. Preferably, the oblique orientation of the fibres forms an angle of 45±10 degrees to the longitudinal axis of the frame.

In another advantageous further development, provision is made that the proximal shape is connected to the feed unit, wherein the two ends of the frame are wrapped by a wire, whose ends are arranged parallel to the ends of the frame. The joining of the proximal shape of the frame to the feed unit is done preferably by means of an adhesive joint. The ends of the frame are inserted into an open lumen of the feed unit where they are glued. The wire which wraps the ends of the frame and consequently secures it, is preferably a stainless steel wire and serves to make the ends of the frame additionally stable. The ends of the wrapped stainless steel wire lie parallel to the ends of the frame wire and are preferably glued together in the feed unit. The transition from the frame wire to the feed unit as well as the wrapped stainless steel wire are preferably sealed flexibly, such as with a polymer mixture, to provide a smooth surface as well as an even transition.

Preferably the frame of the embolic protection device has a basic state in the form of an oval shape. The oval shape matches the native shape of the aortic arch roof and thus enables all three head blood vessels to be covered reliably. The upper area of the aortic arch at this point is shaped like, for example, the inside of an oval, inverted bowl. Thus, by inserting an oval shape, a positive fit is achieved. Preferably, the oval shape is tapered towards the proximal shape. In other words, the cross section through the aorta at the point at which the embolic protection device is placed, is oval so that the oval shape of the frame advantageously adapts to the physiological shape at this point.

According to a second aspect of the invention a forming device for shaping the inventive embolic protection device is provided. The embolic protection device has all or at least some of the mentioned features—they will not be repeated again at this point. The shaping is carried out to feed the embolic protection device into a catheter, wherein the frame of the embolic protection device having the filter unit arranged at it, is transformed from an expanded state to an extended state. The forming device has two subsections which meet at the narrowest cross section. The subsections are each preferably funnel-shaped. The distal subsection is preferably formed as a flat or round funnel and serves as the entrance for the inventive embolic protection device. The proximal subsection is preferably formed as a circular funnel and serves to receive an substantially circular tube, such as a commercially obtainable introducer sheath or a commercially obtainable catheter. The forming device is a tool with a geometry which allows the embolic protection device, in particular its frame, to change its shape in such a way that it has a diameter in the folded state of preferably substantially 1.4-2.0 mm, in particular 1.7-1.8 mm. It is ensured with the forming device that the embolic protection device can be easily put into an substantially circular tube, such as a commercially obtainable introducer sheath or a commercially obtainable catheter.

In a further development, the preferably flat or round opening of the forming device is shaped such that the proximal shape and/or a distal shape of the frame of the embolic protection device can be folded outwards. Amongst other things, this ensures the correct and damage-free introduction of the embolic protection device, for example, into a catheter. In other words, the proximal and/or distal shape(s) which extend(s) in the basic state of the embolic protection device towards the inside of the frame is/are folded in the opposite direction, i.e. outwards, by the flat or round opening.

According to a third aspect of the invention a method for folding the inventive embolic protection device by means of the forming device is provided. The embolic protection device has all or at least some of the mentioned features—they will not be repeated again at this point. The method comprises the steps:

Moving of the frame of the embolic protection device in front of the flat or round opening of the forming device, wherein the feed unit is guided through the forming device; introducing or retracting the proximal shape into the forming device, wherein the proximal shape is folded outwards; hooking the distal shape over the outer edge of the distal subsection of the forming device, wherein, by inserting further, the distal shape folds outwards and is inserted into the forming device.

In a further development of the method, it is advantageously provided that, by inserting the frame in the forming device, the frame is pushed together and is extended longitudinally. Due to the tapering shape of the distal subsection of the forming device, the frame is pushed together from both sides so that, when it leaves to enter the narrowest cross section of the forming device, it has a longitudinally extended shape.

In a further development of the method, it is advantageously provided that the embolic protection device is pushed out of the aforementioned tube, containing the folded embolic protection device and which can be, for example, a commercially obtainable introducer sheath, into a catheter placed beforehand in the aortic arch. A hemostasis valve on the proximal end of the catheter serves here to receive and secure the tube and simultaneously to minimise the loss of blood as the placing is taking place. With a forward push on the feed unit, the embolic protection device is now pushed out of the tube into the catheter. As soon as the frame is located completely in the catheter, the tube can be removed and retracted through the feed unit. The embolic protection device can then be pushed by pushing the feed unit forward and out through the distal end of the catheter into the aorta arch.

In another further development of the method, it is advantageously provided that the embolic protection device is pushed out of the aforementioned tube, which can be, for example, a commercially obtainable catheter, into a sheath placed beforehand in the aortic arch. With a push on the tube through the sheath, the embolic protection device in the tube can be pushed to the distal end of the sheath in the aortic arch.

In all further developments of the inventive embolic protection device, provision is made that the folded up proximal shape transfers a prestress to the frame, which is substantially equal to the tension causing the bent proximal shape to be straightened.

Furthermore, a method for unfolding the embolic protection device from a catheter containing it is also provided. The invention also comprises the provision that the embolic protection device can be received in a longitudinal or cylinder-shaped or catheter-like device due, for example, to the method for folding the embolic protection device. When unfolding the embolic protection device out of the catheter, it is first pushed out until the distal area of the frame has left the catheter. With a further push feeding the embolic protection device out of the catheter, the distal shape is pushed out, which folds back into the inner area of the frame. Due to the folding of the distal shape, the frame in the distal area is restored to the prestressed state before the folding of the embolic protection device. The folding of the distal shape serves as an aid to orientation and makes it possible for the frame of the embolic protection device to change shape so that it can be inserted into practically any catheter. Furthermore, the folding of the distal shape is atraumatic.

At its proximal area, the feed unit can have two markings, wherein the first, with later placement of the embolic protection device through the guide catheter, indicates that the distal shape is located directly in front of the exit opening of the catheter and the second marking indicates that the frame has already left the catheter completely.

In a further advantageous further development, the direction of the frame is displayed by one or more markers. The markers can be radiopaque. The markers can be arranged in particular in the distal area of the frame. The distal area indicates the direction of the frame as it is pushed out of the catheter. The advantage of this is that primarily the position of the frame, the direction in which it is being fed and the placement position can be established precisely.

