Implant for treating arteriovenous malformation

Abstract

The invention relates to an implant for the treatment of arteriovenous malformations, in particular aneurysms, in which the implant can be brought into a target site in the vasculature of a patient in a compressed state by means of a microcatheter, and the implant is imparted with a second structure by means of which it assumes an expanded state when released from the microcatheter, wherein the implant is releasably connected to the insertion aid via a separation site, and wherein the implant in the expanded state has a body having a proximal section and a distal section wherein the proximal section and the distal section have a dome-shaped configuration wherein the convex side of the dome of the proximal section is in a proximal direction and the convex side of the dome of the distal section is in a distal direction. The convex side of the dome of the proximal section faces in the distal direction, and wherein the proximal section and the distal section are connected to each other by a plurality of connecting struts. Alternatively, the implant may have the shape of a closed tulip head. The implant according to the invention can effectively adapt to the shape of a corresponding aneurysm.

Description

[0001] This application is a divisional application of the PCT international invention patent application filed on December 15, 2020, with application number 202080095783.X and invention title "Implant for the Treatment of Aneurysms". Technical Field

[0002] The present invention relates to an implant for treating arteriovenous malformations—particularly aneurysms—that, in a compressed state, can be guided to a destination in a patient’s vascular system via a microcatheter, and that the implant is pre-configured with a second structure that allows the implant to be in an expanded state upon release from the microcatheter, wherein the implant is detachably connected to an insertion aid via a cut or separation point. Background Technology

[0003] Aneurysms are typically sac-like or fusiform dilatations of the blood vessel wall, and due to the constant pressure of blood, they mainly occur in areas of structural weakness in the vessel wall. Therefore, the internal vessel wall of an aneurysm is sensitive and easily damaged. Rupture of an aneurysm usually leads to serious health damage, and in the case of a cerebral aneurysm, it can cause neurological dysfunction and even death.

[0004] Aside from surgical interventions such as clamping the aneurysm, endovascular methods for treating aneurysms are known, primarily employing two approaches. One option involves filling the aneurysm with an occlusive device, particularly using a so-called coil (platinum spiral). The coil facilitates thrombus formation, thus ensuring the aneurysm's occlusion. The other approach is known to use a stent-like implant to block the pathway to the aneurysm from the vessel side, such as the neck of a berry-shaped aneurysm, thereby disconnecting it from blood flow. Both methods aim to reduce blood flow into the aneurysm, thereby alleviating, ideally even eliminating, the pressure acting on the aneurysm and thus reducing the risk of aneurysm rupture.

[0005] When filling an aneurysm with a coil, underfilling can occur, allowing blood flow into the aneurysm and causing continued pressure on its inner wall. The risk of the aneurysm continuing to expand and eventually rupture remains, albeit in a reduced form. Furthermore, this treatment method is only suitable for aneurysms with a relatively narrow neck—so-called berry aneurysms—otherwise there is a risk of the coil protruding into the vessel from the wider neck (where it can form clots), potentially causing occlusion. In the worst case, the coil can be completely flushed out of the aneurysm, causing occlusion in other areas. To hold the coil in place within the aneurysm sac, the aneurysm neck is usually additionally covered with a special stent.

[0006] Another type of endovascular treatment has led to a focus on so-called shunts. These implants are similar in appearance to stents used to treat stenosis. However, because the purpose of shunts is not to keep the blood vessel open, but to block the aneurysm on the side of the vessel, their mesh size is very narrow; alternatively, such implants are coated with a membrane. One disadvantage of these implants is the risk that the outflow branch immediately adjacent to the aneurysm being treated may also be covered and thus closed in the medium to long term.

[0007] WO2012 / 034135A1 discloses an implant comprising first and second parts arranged one after another within a catheter, but which, upon release within an aneurysm, take on a three-dimensional, near-spherical shape and thereby fill the aneurysm. The basic material of the three-dimensional implant is a mesh fabric, and the embodiments and figures are based on a tubular braid composed of shape memory material. A disadvantage of this prior art example has been found to be the unfavorable stiffness of the implant. Since aneurysms are rarely perfectly circular, the three-dimensional implant should be able to adapt to the morphology of the aneurysm in the most feasible way. Furthermore, the implant is too bulky for low-bore catheters.

[0008] Another implant for inserting an aneurysm is disclosed in WO2017 / 089451A1. The implant described therein comprises several subunits, each having a strut frame with a covering arranged between them. However, the implant must first form multiple coils within the aneurysm until adequate coverage of the aneurysm surface is achieved.

[0009] WO2009 / 135166A2 discloses an implant for aneurysms that has a barrel shape and consists of multiple interwoven filaments that converge centrally at a point both proximally and distally. With the aid of this implant, an aneurysm can be blocked using a single implant. However, blood flow may cause the barrel structure to be compressed, resulting in a reduction in the overall volume of the implant. This relates to incomplete filling of the aneurysm.

[0010] Generally, the problem arises on the one hand, the desire for an available implant that can individually fill the aneurysm. However, it must be remembered that aneurysms are often irregularly shaped and vary in size, so a single implant should be able to effectively accommodate these different shapes. It is precisely because of this issue that traditional coils are still frequently used, as they largely fill the space of the aneurysm independently and become entangled during the process, with the attending physician adjusting the number of coils inserted based on the size of the aneurysm. Summary of the Invention

[0011] Based on the prior art mentioned above, the object of the present invention is to provide an implant that, as a single implant or in combination with other occlusion devices, can fill the aneurysm while adapting to the shape and size of the aneurysm.

[0012] According to the first embodiment, this objective is achieved by the proposed invention, which provides an implant for treating arteriovenous malformations—particularly aneurysms—in which the implant can be delivered in a compressed state to a target site in a patient's vascular system via a microcatheter, and the implant is pre-configured as a second structure that allows the implant to be in an expanded state upon release from the microcatheter, wherein the implant is detachably connected to an insertion aid at a dissociation point, and wherein the expanded implant has a base comprising a proximal segment and a distal segment, the proximal and distal segments being dome-shaped, the convex side of the dome of the proximal segment facing proximally, and the convex side of the dome of the distal segment facing distally, and wherein the proximal and distal segments are interconnected by a plurality of connecting struts.

[0013] The implant offers a high degree of flexibility due to its distal and proximal domes and the connecting strut extending between them. This is ensured in both the axial and radial directions; that is, the implant can adapt to available space in the longitudinal direction as well as in the rotational direction about the longitudinal axis. In the expanded state, the implant may be slightly larger than the interior of the aneurysm, but the flexibility generated by the connecting strut extending longitudinally between the distal and proximal domes allows the implant to adapt effectively. For example, the connecting strut can be slightly compressed or twisted to achieve adaptation in the axial or radial directions, respectively. Since the implant is typically slightly larger than the size of the aneurysm to be treated, it anchors itself within the aneurysm. In this case, the connecting strut serves to achieve length compensation and adaptation to the aneurysm. Good anchoring is achieved due to the spring effect.

[0014] The longitudinal direction should be understood as the direction corresponding to or parallel to the axis extending from the proximal to the distal side. Connecting struts extending in the longitudinal direction should also be understood to include those with longitudinal members but not extending in a straight line in the longitudinal direction. In fact, it is advantageous if the connecting struts between the proximal and distal segments are curved, as this ensures flexibility in length. By employing a straighter construction, the connecting struts can be slightly stretched, but if the curvature increases, they can also be compressed together. In this way, the connecting struts exert a certain spring-like effect in both the axial and radial directions. This spring effect improves the anchorage of the implant in the aneurysm. Curved extension is understood as a construction of connecting struts with one or more curved portions.

[0015] In the longitudinal direction, the individual connecting struts extend substantially parallel to each other; that is, the connecting struts do not intersect and generally do not interweave, thus allowing them to compress or stretch independently. Similarly, rotational movement of the distal segment relative to the proximal segment about the longitudinal axis is possible, thus ensuring radial flexibility of the connecting struts. As suggested by the present invention, a substantially parallel configuration of the connecting struts in the longitudinal direction is also possible if the curvatures of the individual connecting struts extend differently.

[0016] The terms "proximal" and "distal" should be understood as follows: when the implant is inserted, the portion facing the attending physician is called the proximal side, and the portion facing away from the attending physician is called the distal side. Typically, the implant is thus moved forward in a distal direction via a microcatheter. For example, the microcatheter may be a microcatheter with an inner diameter of 0.021", 0.027", or 0.033". The term "axial" refers to the longitudinal axis of the implant, which extends from the proximal side to the distal side when the implant is in the extended position, while "radial" refers to the direction orthogonal to it.

[0017] The dome-shaped proximal and distal ends of the implant can also be described as plate-shaped. To better accommodate the shape of the aneurysm, the segments arranged in the distal region are typically slightly rounded toward their respective ends. Furthermore, rounding is particularly non-invasive. The convex bends of the dome or plate thus point toward the distal or proximal end of the implant, while the concave bends point toward the interior of the implant. Depending on the situation, the proximal and distal segments can also be oblique rather than rounded, in which case the generally relatively flat ends are understood as convex. However, the proximal plate, in particular, does not need to be perfectly round; it usually has a rounded portion, but it has a central extension in the proximal direction where the proximal plate terminates toward the separation point. The diameters of the distal and proximal segments are variable in the expanded state and can be appropriately adjusted according to the specific situation, thus allowing treatment of different aneurysm sizes and aneurysm neck sizes. The implant is typically designed such that it presents a diameter larger than the interior diameter of the aneurysm during free expansion. Therefore, the implant secures itself within the aneurysm in a forced closure manner.

[0018] Conveniently, the proximal and / or distal segments consist of frame struts that are at least partially connected to each other. These frame struts can form a mesh or ring structure, particularly in the proximal and / or distal segments. The frame struts thus intersect at certain intersections, creating gaps between the frame struts. These gaps or meshes / rings can have different shapes and, for example, can be honeycomb, rhomboid, or flower-shaped with rounded edges. The advantage of rounded shapes is that they are particularly non-invasive. However, the gaps / gaps need not be completely surrounded by struts; for example, these rings may preferably have an opening on one side, which will further increase the flexibility of the segment. Viewed from the distal or proximal side, the implant can, for example, have 3 to 8 rings arranged in a circular pattern.

[0019] In terms of its main structure, the implant's matrix is ​​therefore preferably composed of frame struts forming the proximal and distal segments and connecting struts that connect the proximal and distal segments to each other. The struts are designed to ensure that the implant is easy to fold and unfold for placement in or release from the microcatheter.

[0020] Connecting struts link the proximal and distal sections. The total number of connecting struts can be, for example, 3 to 10, particularly 6 to 8. The connection points between the connecting struts and the distal or proximal sections, which are typically composed of frame struts, can be arranged in various ways, and for example, they can be arranged in the same plane, but also offset from each other. The length and shape of the connecting struts can also be the same, or they can be different. For example, in the case of staggered connection points, it may also be necessary to arrange connecting struts of different lengths. Different cross-sections can also be selected for the connecting struts according to the intended use requirements.

[0021] Specifically, the implant's struts (frame struts and connecting struts) can be manufactured using laser cutting technology. However, it is also feasible to provide a woven structure for the matrix, where individual struts are interwoven or woven together. Other manufacturing processes can also be employed, such as electroplating or photolithography, 3D printing, or rapid prototyping. The provided struts can have circular, oval, square, or rectangular cross-sections; in the case of square or rectangular cross-sections, the edges can have a rounded construction. Individual struts can also consist of several individual filaments twisted together or extending in parallel.

[0022] Conveniently, the distal segment may include a region without frame struts, which is expandable and compressible. This region is preferably centrally located within the distal segment, thus arranging it approximately at the distal end of the matrix. In the case of a preferred mesh / ring structure, this thus creates an opening in the distal segment between the meshes / rings. This region causes the size of the distal segment to adapt to the requirements within the aneurysm, particularly regarding circumference. Different sizes and numbers of meshes / rings can be selected to meet specific application needs. As determined by the size and shape of the aneurysm, the distal segment can be expanded or compressed to a greater or lesser degree, achieving flexibility through the (central) region without frame struts. This region thus generates a certain amount of elasticity or spring effect.

[0023] Particularly preferably, a membrane is provided that at least partially covers the proximal segment, thus covering the neck of the aneurysm and largely preventing blood from flowing into the aneurysm. By disconnecting the aneurysm from blood flow, it eventually shrinks / degenerates, and the risk of aneurysm rupture is eliminated, in which the membrane thus has a blood flow regulating function.

[0024] The membrane does not necessarily have to be limited to the proximal segment; it can also be placed on the distal segment, and / or the connecting struts can also be fitted with a membrane. If there are areas in the distal segment where the frame struts are not arranged as described above, then those areas should also be without a membrane. Placing an additional membrane will enhance the blood flow regulation effect of the membrane(s). Furthermore, it further reduces the risk associated with endoleak—that is, blood flowing in through the gap between the implant and the aneurysm sac.

[0025] According to a second embodiment, the present invention relates to an implant for treating arteriovenous malformations, particularly aneurysms, which, in a compressed state, can be guided via a microcatheter to a destination in a patient's vascular system. The implant is pre-configured with a second structure that allows it to expand upon release from the microcatheter. The implant is detachably connected to an insertion aid via a cut or separation point. In the expanded state, it has a base composed of struts that are at least partially interconnected at their intersection points, creating a gap between the struts. In the expanded state, the struts extend radially outward at the proximal end of the base and, further in a distal direction, extend axially and radially inward, creating a protrusion of the base. The base has a region at its distal end in which the struts are not connected to each other. In the expanded state, the base may, in particular, have an opening at its distal end.

[0026] According to this second embodiment, the expanded matrix has a closed tulip shape. The struts converge centrally at the separation point proximally. Starting from the separation point, the struts first extend radially outward, then further distally, while again approaching the central longitudinal axis. In some cases, the struts may also extend proximally in their radially outwardly extending portions, resulting in an inwardly curved portion of the matrix as a whole at the proximal end. The struts are at least partially interconnected, creating an intermediate space or mesh between the edges of the struts. This space or mesh can have different shapes, such as honeycomb, heart-shaped, leaf-shaped, or rhomboid, and the edges of the intermediate space / mesh are typically rounded. The interconnected struts can form segments resembling tulip petals; that is, several petal-shaped segments emanate from the proximal end of the matrix and form the outer surface of the matrix distributed circumferentially, the segments closely abutting the inner wall of the aneurysm. These segments converge at the proximal end of the matrix. In this way, a matrix is ​​created where the individual segments are elastic and movable, thus adapting well to the shape of the aneurysm, enabling non-invasive implantation. The elastic distal end of the strut / segment serves as a support to push the proximal end of the matrix into the neck of the aneurysm, thereby promoting a good seal between the aneurysm and the blood flow.

[0027] At the distal end, the pillars are not connected to each other, so the matrix is ​​open here. However, the pillars or segments formed by the pillars can overlap at the distal end, so that the opening is effectively closed, but the opening at the distal end can be preserved if each pillar / segment terminates in front of the opening on the distal side.

[0028] Typically, the matrix is ​​largely adapted to the shape of the aneurysm; that is, the struts first extend radially outward to the aneurysm wall and then continue further distally along it, forming a radially inward curved portion. Therefore, the exact shape of the matrix formed within the aneurysm also depends on the shape of the aneurysm. Whether the opening is retained at the distal end of the matrix or whether the struts overlap also depends on the shape of the aneurysm. In the case of aneurysms that are relatively small relative to the body, the struts can, for example, be compressed to the point where their distal ends overlap and the opening disappears, while in larger aneurysms, the distal opening can be retained. In the expanded state, the implant may be slightly larger than the interior of the aneurysm, but the flexibility created by the struts allows for effective adaptation of the implant. Since the size of the implant is usually slightly too large compared to the size of the aneurysm to be treated, the implant anchors itself within the aneurysm. The shape of the matrix resembles a closed tulip flower, but can also be described as a upset spherical or ellipsoidal shape, although this is understood to mean not only a precise geometry but also a shape that at least approximates the relevant geometry. Typically, a flattened or centrally located expansion base at the proximal end can be used to prevent the implant from extending beyond the aneurysm and entering the maternal blood vessel.

[0029] Regarding the struts of the second embodiment of the invention, the same applies to the description of the first embodiment; that is, the struts of the implant can be specifically manufactured using laser cutting technology, but it is also feasible for them to have a woven structure in the form of a matrix, including individual struts woven or woven together. Other manufacturing processes can also be used, such as electroplating or photolithography, 3D printing, or rapid prototyping. The provided struts can have circular, oval, square, or rectangular cross-sections; in the case of square or rectangular cross-sections, the edges can have a rounded construction. Individual struts can also consist of several individual filaments that are twisted together or extend in parallel.

[0030] Similarly, according to the second embodiment, one or more membranes can be provided to cover the substrate. Particularly preferred is a membrane provided in the proximal region of the substrate, capable of achieving at least partial coverage. As a result, the membrane covers the neck of the aneurysm and largely prevents blood from flowing into the aneurysm. Disconnecting the aneurysm from blood flow leads to its eventual shrinkage / degeneration and eliminates the risk of aneurysm rupture; therefore, the membrane has a blood flow regulating function.

[0031] The membrane need not be confined to the proximal region of the matrix; a membrane can also be placed in the distal region. However, if the distal ends of the struts do not overlap significantly, there is usually no membrane at the distal end with the opening. By providing membranes in other regions of the matrix, the blood flow regulation effect of the membrane(s) is enhanced. Furthermore, the risk associated with endoleak—that is, blood flowing in through the gap between the implant and the aneurysm sac—is further reduced.

[0032] Regardless of the embodiment, the implant is preferably made at least partially of a shape memory material. This allows the desired second structure to be pre-defined in the implant, which automatically adopts that form upon exiting the microcatheter. Shape memory metals are particularly well-known in the field of medical engineering, among which nickel-titanium alloys, such as those used under the name Nitinol, deserve special mention. Typically, the second structure forms upon exiting the microcatheter due to the removal of external constraints imposed by the microcatheter; however, it is also possible for the second structure to form due to temperature changes that occur upon exiting the microcatheter.

[0033] The implant can be detachably connected to an insertion aid via a separation / cutting point. This insertion aid can be a conventional push suture used to advance the implant through the vascular system to the desired location. However, an insertion aid with a tubular or flexible design and a lumen is particularly preferred. With the aid of such an insertion aid, after the matrix is ​​inserted into the aneurysm and dilated there, additional occlusion devices can be inserted into the interior of the aneurysm and / or the matrix, thereby achieving further occlusion of the aneurysm. It is also contemplated to use the insertion aid to introduce other filling materials into the aneurysm, filling materials known from the prior art, such as viscous embolic materials, for example, onyx.

[0034] It is advantageous to use additional occlusion devices or materials for filling because it prevents external forces from compressing (clamping) the implant. In practice, an aneurysm may act externally on the inserted implant, which is hollow inside. The implant may then be compressed and no longer able to completely fill the aneurysm, or may partially expel the aneurysm, leading to obstruction of blood flow in the maternal vessel. This is prevented by additionally filling the interior of the implant with an occlusion device or material introduced through a tubular or flexible insertion aid.

[0035] Furthermore, additionally inserted occlusion devices can fill the gap between the implant exterior and the aneurysm inner wall. This is particularly important when treating irregularly shaped aneurysms. To allow additionally introduced occlusion devices, especially conventional occlusion coils, into the space between the implant exterior and the aneurysm inner wall, the distal segment or distal region of the matrix should not be covered by a membrane; instead, if a membrane is provided, it should be confined to the proximal segment or proximal region. It is considered particularly advantageous that tubular or flexible insertion aids terminate approximately in the middle of the latter when the matrix expands, allowing the occlusion device introduced via the insertion aid to migrate outward from there and through the gap between the struts into the area between the implant and the aneurysm.

[0036] If the insertion aid has a lumen, the insertion of additional occlusion devices or materials is significantly simplified. With membrane-covered implants, there is a real question of exploration regarding how to introduce additional occlusion devices or materials into the aneurysm to achieve the most complete possible seal to prevent blood flow into the maternal vessel. Subsequent insertions might require introducing another catheter and puncturing the implant's membrane. As proposed in this invention, this is significantly simplified because the insertion of the occlusion device or material can be completed during implantation. Preferably, the implant is first expanded within the aneurysm, but not yet dissected. The occlusion device is then introduced through a tubular or flexible insertion aid. Finally, dissection and final release of the implant occur, allowing the insertion aid and microcatheter to be withdrawn proximally.

[0037] Insertion aids with internal lumens can be implemented in various ways, but they should certainly provide sufficient flexibility to allow the insertion aid to navigate through narrow-lumen vessels, especially those located intracranial. For example, the insertion aid can be a catheter-type design, i.e., it can be composed of a braided fabric of metal and / or plastic materials. However, the insertion aid can also be designed as a tubular thiocarbide tube. For example, the tube can be made of a flexible polymer material or a metal helical structure, and in the case of a metal helical structure, multiple layers can be provided, typically up to four layers, preferably two layers. These layers thus form a hollow structure consisting of one or more helices. In the case of a multi-layered metal helical structure, the helical configurations of two adjacent layers are preferably opposite, i.e., a right-hand helical structure is above a left-hand helical structure, and vice versa. The helical structures thus twist in opposite directions. Providing several layers with opposite configurations is considered useful so that the tube can transmit torsional motion from the proximal to the distal side.

[0038] In the case of tubing made of polymer materials, slits can be provided in the tubing to further increase the flexibility of the hose.

[0039] For linear and tubular or flexible insertion aids, it is advantageous if flexibility increases from proximal to distal. This ensures that, on the one hand, the insertion aid has sufficient rigidity in the proximal region to allow for advancement and the transmission of torsional forces, but on the other hand, the insertion aid is flexible enough in the distal region to navigate through narrow blood vessels. For example, the diameter can decrease from proximal to distal, and this decrease can be gradual or occur in one or more steps.

[0040] Insertion aids can also be constructed from multiple components. In particular, in the case of tubular or flexible insertion aids, the proximal region can be designed as a tubular subcortex tube, while the distal region can be designed as a flexible conduit.

[0041] Regardless of how the insertion aid is manufactured, it is delivered to the target location via microcatheters. This also applies if the insertion aid itself is a conduit-like design. Furthermore, an external friction-reducing coating on the insertion aid is considered advantageous, for example, using PTFE (polytetrafluoroethylene, Teflon).

[0042] Separation of the implant from the insertion aid is achieved by electrolytic, thermal, mechanical, or chemical means. Electrolytic separation methods involve electrolytically corroding the separation point by applying voltage, causing the implant to disconnect from the insertion aid. To prevent anodizing of the implant, it should be electrically isolated from the separation point and the insertion aid. Electrolytic separation of implants is a well-known practice in the prior art, particularly for coils used to close aneurysms. For example, a related cut / separation point is described in publication WO2011 / 147567A1. This principle is based on the fact that, when voltage is applied, a properly designed separation point made of a suitable material (particularly a metal) is typically dissolved by anodizing to such an extent that the region of the implant located distal to the corresponding separation point is released. The cut point can be made of, for example, stainless steel, magnesium, magnesium alloys, or cobalt-chromium alloys. A particularly preferred magnesium alloy is… It was developed by MeKo from Sarstedt / Germany (see WO2013 / 024125A1). It is an alloy composed of magnesium and, in particular, lanthanides, especially dysprosium. Another advantage of using magnesium and magnesium alloys is that the magnesium residue remaining in the body poses no physiological problem.

[0043] Dissolution at the separation point is induced by the application of voltage. This can be alternating current or direct current, with a low current intensity (<3mA) sufficient. In this case, the separation point typically acts as the anode, its metal being oxidized and dissolved. It is important that the separation point be electrically connected to the voltage source, especially via an insert. For this purpose, the insert itself must also be designed to be conductive. Due to the fact that the corrosion-induced current is influenced by the surface of the cathode, the cathode surface should be significantly larger than the anode surface. To some extent, the rate of dissolution at the separation point can be controlled by appropriately determining the dimensions of the cathode surface relative to the anode surface. Therefore, the invention also relates to an apparatus comprising a power source and, where applicable or suitable, electrodes to be placed on a body surface.

[0044] Specifically, the separation point can take the form of a separation element arranged outside the insertion aid and connected to the proximal end of the substrate. Applying voltage causes the connection between the separation element and the substrate to corrode to the extent that separation / cutting and release of the implant is achieved. Preferably, the separation element is arranged circumferentially around the insertion aid such that the element can form a disk with a central hole through which the insertion aid can pass. One or more separation wires can be attached to the separation element, which advantageously have insulation to allow voltage to be applied to the separation point in a concentrated manner. The separation wires (one or more) can be wired outside the insertion aid or through the interior of the insertion aid. If the insertion aid is made of metal, especially if it has a conduit-like design including a metal braid, current can also be supplied through the metal braid.

[0045] As already mentioned, it is advantageous if the insertable aid extends into the matrix in an expanded state. In particular, tubular or flexible insertable aids can extend distally beyond the dissociation point. In the embodiment described above, which provides a dissociation element circumferentially surrounding the insertable aid, the dissociation element is thus positioned closer to the distal end of the insertable aid. Therefore, the matrix can be introduced into the aneurysm first and expanded by withdrawing the microcatheter. A further occlusion device, particularly a coil, can then be introduced into the matrix via the insertable aid protruding into the matrix. Once this process is complete, implant dissociation occurs, and the microcatheter and insertable aid are eventually removed from the vascular system.

[0046] In cases of mechanical separation / cutting, a shape-closed, force-closed, or friction-fitted connection is typically present, which is disrupted when the implant is released, causing separation from the insertion aid. One option is to provide a radial protrusion in a distal region on the lateral side of the insertion aid, the distal region protruding into the implant. A microcatheter is positioned around the insertion aid. In this way, a friction-fitted connection is established between the insertion aid, the proximal end of the implant, and the microcatheter. When the microcatheter retracts proximally relative to the implant and the insertion aid, the external contraction caused by the microcatheter is eliminated, causing the proximal end of the implant to radially expand and disengage from the protrusion; i.e., friction-fit disengagement.

[0047] In this context, the distal region of the insertion aid is understood as the area further distal to the implant that interacts with it, but it is not necessarily the distal end of the insertion aid; it often extends even further into the implant to facilitate the placement of the occlusive device. Radial protrusions are those that project outwards in the radial direction—that is, perpendicular to the longitudinal axis of the insertion aid.

[0048] External constraints preventing proximal expansion cannot always be caused by the microcatheter; an additional sheath can also be provided around the distal end of the insertion aid, pressing the proximal end of the implant against the insertion aid. To enable release, this sheath must, of course, also be retractable proximally relative to the insertion aid and the implant.

[0049] The radial protrusions can be made of elastic materials, particularly elastomeric materials. The proximal end of the implant is pressed against the insertion aid by a microcatheter or sheath and is almost clamped in place, thus achieving a friction-fit connection. In particular, the protrusions can be shaped as pads. The pads can surround the insertion aid in a ring-like form, wherein several radially extending rings or helical structures can be provided to achieve a particularly secure fastening.

[0050] The proximal end of the implant may also have a thickened portion, which, for example, is held between the radial protrusions of the insertion aid. For example, the thickened portion may be spherical or have a similar geometry. In this case, the fixation of the implant to the insertion aid is a combination of friction fit and shape-closure fit.

[0051] To allow the attending physician to visualize the separation, radiopaque markings located in the area where the implant is attached to the insertion aid are advantageous. For example, radiopaque markings may be provided in this area on the proximal end of the insertion aid, microcatheter, and / or implant, or on the sheath surrounding the insertion aid, and their movement, particularly their movement relative to each other, can be observed using radiographic techniques.

[0052] Another feasible approach is to provide a purely shape-closure fastening method. In this regard, a disengagement element can be positioned proximally to the implant, engaging in a shape-closure manner within a recess provided for this purpose in a tubular or tubular insertion aid. The fact that the insertion aid is surrounded by a microcatheter or additional sheath prevents the disengagement element from radially expanding and leaving the recess. This ensures that the disengagement element remains securely within the recess as long as the microcatheter or sheath does not retract proximally. Only when the microcatheter / sheath moves proximally and no longer covers the recess can the disengagement element leave the recess, resulting in disengagement and ultimately, release of the implant. The recess in the insertion aid can surround the entire wall of the insertion aid or simply be recessed into that wall as a depression.

[0053] According to another variation, one or more disengagement elements extend proximally at the proximal end of the implant and are held in place in a shape-closed manner by one or more retaining elements arranged on the insertion aid. The retaining elements are made of a material with shape memory properties, wherein the retaining element is pre-programmed to present a second structure that it attempts to present but is prevented from occupying as soon as the microcatheter or a separate sheath surrounds the retaining element. External constraints, in particular, prevent the retaining element from occupying the second structure; however, the retaining element may also undergo temperature changes after the microcatheter / sheath has retracted, causing the element to present its second structure. When its second structure is presented, the retaining element opens and releases the disengagement elements, resulting in implant disengagement.

[0054] For example, in this embodiment, the separating element may be spherical, and the retaining element may surround the separating element in a shell-like manner. The spherical separating element can be disengaged as the shell-like retaining element expands. Separation can be achieved for a single separating element interacting with a single retaining element, but it is also preferable to combine multiple retaining elements with associated separating elements along the circumference of the insertion aid to ensure uniform release over the entire circumference.

[0055] Regardless of whether electrolytic or mechanical separation is involved, the proximal end of the implant retained at the separation point can be specifically provided in the form of a proximal line, the connection of which to the separation element / separation point is released for the purpose of disconnecting the implant. Especially in the case of mechanical separation, an additional separation element can be attached to the proximal line fixed by an insertion aid.

[0056] Another option is to design the separation point as a thermal separation point. In the case of a thermal separation point, the connection between longitudinally adjacent portions of the implant can be disrupted by heating the separation point, causing it to soften or melt, thereby achieving separation. Another option is to utilize chemical transection in such a way that separation is caused by a chemical reaction occurring at the separation point.

[0057] Different types of separation can also be combined, such as electrolytic separation and mechanical separation. For this purpose, mechanical connections are established between components, especially mechanical connections created by form fit, and these connections remain in place until the component maintaining the mechanical connection is electrolytically corroded.

[0058] Regarding the combination of electrolytic and mechanical separation, one option is to provide an insertion aid end piece at the distal end of the insertion aid, said end piece having an electrolytically etchable separation point, which is connected to the implant end piece at the proximal end of the implant via an insulating element. Specifically, a shape-closed connection may exist between the insertion aid end piece, the insulating element, and the implant end piece to ensure a secure attachment between the insertion aid and the implant during advancement through the microcatheter. Furthermore, the shape-closed connection also ensures proper transmission of torsional motion.

[0059] The insertion aid end piece is preferably made at least partially of a metal that ensures conductivity at the separation point, meaning that current can be applied to the insertion aid and conducted to the separation point. To enable current application at the separation point, it is also conceivable to provide a separate conductor insulated from the insertion aid itself. The separation point typically serves as the anode, causing the metal used for the separation point to oxidize, and thus leading to the dissolution of the separation point. The cathode is typically an electrode disposed on the patient's body surface; however, another electrical conductor may be provided on or through the insertion aid to close the circuit acting on the separation point. Preferably, at least the separation point is made of a metal that dissolves well by electrolysis or electroplating, such as a cobalt-chromium alloy; however, other stainless steel alloys are also possible. Optionally, the separation point may be subjected to pre-corrosion to improve its dissolution characteristics.

[0060] In most cases, implant tips are also made of metal. It is advantageous to manufacture implants from metals with shape memory properties, such as, in particular, nickel-titanium alloys, or from metals that dissolve relatively quickly in the body, such as magnesium. This way, over time, the area of ​​the implant that is only needed, not permanently, will disappear. The more distal areas of the insertion aid tips (which remain in the body after dissection) can also be made of magnesium, for example. Therefore, unwanted foreign matter will dissolve.

[0061] An insulating element positioned between the insertion aid and the implant terminal ensures that the implant is insulated from the applied voltage, thereby concentrating the current at the separation point. This insulating element is made of an electrically insulating material. The form fit between the two terminals is preferably achieved / transmitted through the insulating element.

[0062] According to a particularly preferred embodiment, both the insertion aid end piece and the implant end piece include a first short tubular element, at which a narrow connecting web is disposed and extends longitudinally toward a second short tubular element, which has an interruption / cutout on its circumference. Preferably, when viewed radially, the interruption / cutout is located opposite the connecting web. An insulating element is adapted to the two ends in such a way that the respective second tubular elements with their cutouts can each engage with a portion of the insulating element, the two portions of which are arranged longitudinally back-to-back with each other. Each of these portions provides space to accommodate the second tubular element. In this case, the longitudinal direction is understood as from proximal to distal, and vice versa.

[0063] When the insertion aid end piece, insulating end piece, and implant end piece are connected together, the second tubular element of the implant end piece is located proximal to the first tubular element, while the second tubular element of the insertion aid end piece is located distal to the first tubular element. The second tubular element of the implant end piece engages in a receiving space of a portion of the insulating element positioned more proximal to it, while the second tubular element of the insertion aid end piece engages in a receiving space of a portion of the insulating element arranged more distally to it. Therefore, the insertion aid end piece and the implant end piece ultimately engage with each other, but always through an interface layer formed by the insulating element. In the assembled configuration, the second tubular element of the implant end piece is located proximal to the second tubular element of the insertion aid end piece. The interruption / cutout in the second tubular element of the end piece is typically located in a radially opposite position.

[0064] The separation point is conveniently located in the region of the narrow connecting web of the insertion aid end piece, for example, where the connecting web of the insertion aid end piece connects to the first continuous tubular element. By applying a voltage, the separation point can be readily corroded and dissolved, at least to the extent that the region of the insertion aid end piece, i.e., the first tubular element, separates from the rest of the separation element. In this context, the term separation element is understood to refer to the entirety of the insertion aid end piece, the insulating element, and the implant end piece. The implant, along with the implant end piece, the insulating element, and the additional distal region of the insertion aid end piece, thus remains in the body, while the proximal region of the insertion aid end piece remains connected to the insertion aid and is removed from the body.

[0065] The described separation element—which represents a combination of a mechanical connection locked by shape closure and electrolytic separability—offers particular advantage in the mechanical security of the connection, providing this security, for example, even when the insertion aid is withdrawn in the proximal direction. The mechanical connection remains even after the microcatheter has been withdrawn or when the microcatheter has been withdrawn. Separation occurs only when voltage is applied to the separation element and in a well-controlled manner.

[0066] Essentially, the aforementioned separation element can also be used to insert any other implant. This is particularly true for the last described embodiment, which involves a combination of electrolytic separation and mechanical connection, and is therefore especially safe to use. Thus, the present invention includes a corresponding separation system even if the implant itself has a design that does not conform to the design and construction detailed in this patent application.

[0067] The dissociation point can be located proximal to the matrix, but as described above, it is preferably provided within the matrix or implant, which causes the insertion aid to extend into the implant in an expanded state. On the one hand, in the case of a tubular or flexible design of the insertion aid, this facilitates the insertion of further occlusion devices, and on the other hand, the struts forming the proximal segment or region can converge at least partially at the dissociation point, resulting in slight indentation / inward bending in the proximal segment / region. Indentation in the proximal mid- and distal segments / regions is associated with the advantage that invasive support ends are excluded, or cannot contact the aneurysm wall, as they are repositioned within the matrix.

[0068] Membrane covering should be understood to refer to any arrangement having a corresponding strut or segment of membrane, whether the membrane is applied to the outside or inside of the strut / segment, or whether the strut / segment is embedded in the membrane, the latter being preferred.

[0069] When the implant includes a membrane, it can self-separate and occlude the aneurysm from the blood flow, meaning that no additional occlusion device, such as a coil or similar, is required. The membrane provides sufficient elasticity to not impede the folding and unfolding of the implant, and the membrane is not damaged in the process. A membrane positioned in the proximal segment or region of the implant is particularly advantageous because it forms a seal against the maternal vessel in this way. Typically, inserting a single suitable implant into the aneurysm is sufficient, but several implants as proposed in this invention can also be used. Furthermore, as described above, an occlusion device or occlusion material can be placed within the implant. In this case, an insertion aid with a lumen is particularly advantageous. A stent or shunt can also be placed in the maternal vessel.

[0070] However, embodiments of the invention are also conceivable in which the substrate is not equipped with a membrane. In this case, the implant is typically used as a support structure to hold other implants, such as coils, smaller inventive implants with or without membranes, or even other occlusion devices as described in the introductory section. It is also conceivable to combine the implants proposed in this invention with other filling materials (as they are known in the prior art), such as viscous embolic materials like onyx. Unless a further occlusion device or material has been introduced during implantation, the procedure typically begins with inserting the implant into the aneurysm, followed by inserting a microcatheter between the struts forming the implant, and introducing an occlusive or embolic agent into the aneurysm through the microcatheter.

[0071] Within the framework of this invention, reference is made to membranes in a plural form, and it is explicitly stated herein that no separation is required between the individual membranes; rather, the individual membranes can be well bonded together and thus form a monolithic membrane. Conversely, a membrane, such as a membrane covering a proximal segment or proximal region, can also consist of several individual membranes, each designed to cover / fill a mesh / ring in the proximal segment.

[0072] Within the scope of this invention, a membrane is a thin structure having a flat surface, whether the structure is liquid-permeable, impermeable, or partially permeable. However, for the purpose of aneurysm treatment, a membrane that is completely or at least substantially impermeable to fluids such as blood is preferred. Furthermore, the membrane may be designed to include orifices through which additional occlusion devices can be introduced. Another option is to design the membrane in such a way that it can be punctured by a microcatheter to introduce additional occlusion devices, or even punctured by the occlusion device itself.

[0073] The membrane can be made of polymer fibers or thin films. Preferably, the membrane is produced by an electrospinning process. In this process, struts are typically embedded in the membrane. This can be achieved by rotating or weaving fibers around the struts—particularly the frame struts of the proximal and / or distal segments.

[0074] In electrospinning, fibrils or fibers are separated from a polymer solution and deposited onto a substrate by applying an electric current. This deposition causes the fibrils to coalesce into a nonwoven fabric. Typically, the fibrils have diameters ranging from 100 to 3000 nm. Membranes produced by electrospinning have a very uniform texture. The membranes are tough, able to withstand mechanical stress, and can be mechanically punctured without openings, thus creating cracks that propagate from them. Another advantage of electrospun membranes is their ability to establish a large contact surface with blood. The thickness and porosity of the fibrils can be controlled by appropriately selecting process parameters. In the production of membranes and with regard to materials suitable for this purpose, particular attention is paid to disclosures WO2008 / 049386A1, DE2806030A1, and the references therein.

[0075] Instead of electrospinning, membranes can also be produced through impregnation or spray coating processes, such as spray coating. Regarding the membrane material, it is important that the mechanical stresses generated when the implant is pulled into the microcatheter, deployed, or unfolded do not damage it. To ensure this, the membrane should have sufficient elasticity.

[0076] The membrane can be composed of polymeric materials such as polytetrafluoroethylene, polyester, polyamide, polyurethane, or polyolefin. Polycarbonate urethane (PCU), particularly electrospun polycarbonate urethane, is particularly preferred. In particular, integral bonding between the membrane and the support / segment is desirable. This integral bonding can be achieved through covalent bonds provided between the membrane and the support / segment. The formation of covalent bonds is promoted by the silanization of the support / segment, i.e., by the chemical bonding of silicon—especially silane—compounds to at least a portion of the surface of the support / segment. On the surface, silicon and silane compounds, for example, are attached to hydroxyl and carboxyl groups. Essentially, other mediated adhesion methods between the support / segment and the membrane, besides silanization, are also conceivable.

[0077] In this case, the silane compound should be considered to follow the general formula R. m SiX n All those compounds (m, n = 0-4, where R represents an organic group, particularly alkyl, alkenyl, or aryl, and X represents a hydrolyzable group, particularly OR, OH, or halogen, where R = alkyl, alkenyl, or aryl). In particular, silanes can have the general formula RSiX3. Furthermore, related compounds having multiple silicon atoms also belong to the silane compound category. Specifically, silane derivatives in the form of organosilicon compounds are considered silane compounds in this context.

[0078] Other substances that promote thrombus formation or endothelial formation can be embedded or deposited on the membrane. Thrombus-promoting substances are therefore advantageous because they support the formation of thrombi or clots within the aneurysm, which ensures permanent occlusion of the aneurysm. One example in this regard is nylon filaments. Because aneurysms are caused by degenerative diseases of the vessel wall, particularly atherosclerosis, promoting endothelial formation and correcting endothelial dysfunction may also have beneficial effects. This is particularly applicable to areas where the aneurysm comes into contact with blood flow in the actual vessel (the parent vessel). Preferably, thrombus-promoting substances are applied to the inner side of the membrane, while endothelial-promoting substances are applied to the outer side of the membrane, where the outer side is understood to refer to the side of the membrane facing the vessel wall in the implanted state, and the inner side is understood to refer to the side of the membrane facing the interior of the aneurysm. Examples of thrombus-promoting substances include collagen, while hyaluronic acid, statins (3-hydroxy-3-methylglutaryl-CoA reductase inhibitors), and other polymers can promote endothelial cell colonization. Polysaccharides capable of mimicking the glycocalyx, especially glycosaminoglycans, are particularly suitable polymers. Another material that can be used is POSS-PCU (polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane). It is a nanocomposite material that has been described, among other applications, as a scaffold for artificial organs and a coating for medical devices (Tan et al., Crit Rev. Biomed Eng. 2013; 41(6):495-513). POSS-PCL (polyhedral oligomeric silsesquioxane poly(caprolactone-urea) urethane) can also be used. Functionalized derivatives of both POSS-PCU and POSS-PCL are also applicable, especially those that can be obtained by linking with polyacrylic acid (poly-AA). Since the POSS-PCU and / or POSS-PCL nanocomposite polymers are only less suitable for direct fixation onto the implant surface, it has been found advantageous to combine polymers such as polyacrylic acid (poly-AA) with nanocomposite materials. This can be achieved, for example, by plasma polymerization of acrylic acid. The poly(AA-g-POSS-PCU) surface obtained in this manner promotes collagen binding (especially type I collagen) and thus promotes endothelial formation (see Solouk et al., Mater Sci Eng C Mater Biol Appl. 2015; 46: 400-408). Some additives, such as collagen or hyaluronic acid, are also advantageous because they can improve friction against the inner side of the catheter during implant advancement and the biocompatibility of the implant. Typically, a biofunctional or bioactive coating can be present on the membrane.

[0079] Preferably, the matrix in its expanded state has an approximate spherical, ellipsoidal, oval, or cylindrical shape with an outwardly convex curved base. In particular, in the case of the second embodiment, the shape of the matrix in its expanded state can also be described as a closed tulip flower. In this case, the given geometry is understood not only as an exact shape but also as a shape at least approximating the corresponding geometry. Essentially, a spherical shape is well-suited for filling regularly shaped aneurysms. However, when the implant is longitudinally compressed or stretched, the resulting shape can be more accurately described as ellipsoidal, or a cylindrical shape with a convex, outwardly curved base region, depending on the degree of rounding / camber of the proximal and distal domes and the stretching / compression of the matrix in the longitudinal direction. In this case, the base region of the cylinder is considered the end face. Depending on the intended application, the diameter or length of the matrix in its expanded state is typically between 4 and 25 mm. Such a diameter is sufficient to fill typical aneurysms, especially those located in intracranial regions. The actual diameter generated within an aneurysm may vary, thus allowing the use of implants to treat aneurysms of different sizes and aneurysms with necks of different sizes.

[0080] Conveniently, one or more radiopaque markers are provided on the implant, allowing the attending physician to visualize the treatment. These may include, for example, spiral structures, helices, or rivets made of radiopaque material, attached to the implant. Radiopaque markers on microcatheters are also useful, as mentioned above. Radiopaque markers may consist, for example, of platinum, palladium, platinum-iridium, tantalum, gold, tungsten, or other radiopaque metals. It is also feasible to provide a coating of radiopaque material, such as a gold coating, to the implant, particularly the struts of the matrix. For example, this coating may have a thickness of 1 to 6 μm. It is not necessary to apply a coating of radiopaque material to the entire matrix. However, even when applying a radiopaque coating, placing one or more radiopaque markers on the implant, particularly at the distal end of the implant, is considered useful.

[0081] Another method to render the implant radiopaque is to embed a radiopaque substance, such as a heavy metal salt like barium sulfate, into the membrane. Such substances are known, for example, as contrast agents in X-ray technology applications.

[0082] Another option involves using struts made of metals with shape memory properties—especially suitable nickel-titanium alloys that at least partially include a platinum core. Such struts are called DFT (drawn filled tube) wires. In this way, the advantageous properties of nickel-titanium, namely imparting shape memory, are combined with the advantageous properties provided by platinum, namely ensuring X-ray visibility.

[0083] The implant provided by the proposed invention is particularly suitable for the treatment of intracranial aneurysms, but it can also be considered for use in other types of aneurysms, such as aortic aneurysms or peripheral aneurysms, in which case the size of the implant will be appropriately adjusted.

[0084] In addition to the implant itself, this invention relates to the use of the implant to treat arteriovenous malformations, particularly aneurysms. All descriptions of the implant itself also apply in a similar manner to the use of the implant and the methods of using the implant.

[0085] Further description of the invention is provided by way of example with reference to the accompanying drawings. It should be noted that the drawings illustrate preferred embodiments and variations of the invention, and the invention itself is not limited thereto. Within the scope of technical convenience, the invention particularly includes any alternative combinations of technical features set forth in the claims or description as relevant to the invention. Attached Figure Description

[0086] The invention is described in the following figures, wherein:

[0087] Figure 1 A side view of an inventive implant in an aneurysm according to a first embodiment is shown;

[0088] Figure 2 The view from the far side of XX shows the view from Figure 1 The implant of the present invention;

[0089] Figure 3 This is a side view of an inventive implant according to a first embodiment of the present invention, wherein the separation point is located near the substrate;

[0090] Figure 4 This is a side view of an inventive implant according to a first embodiment of the present invention, wherein the separation point is arranged inside the matrix;

[0091] Figure 5 An implant placed in an aneurysm according to a first embodiment is shown, wherein a membrane covers the proximal segment;

[0092] Figure 6 An implant placed in an aneurysm according to a first embodiment is shown, wherein a membrane covers the proximal and distal segments;

[0093] Figure 7 An implant without a membrane, placed in an aneurysm according to a first embodiment, is shown, wherein the dissection point is arranged proximal to the base;

[0094] Figure 8 An implant without a membrane, placed in an aneurysm according to a first embodiment, is shown, wherein the dissociation point is arranged in the matrix;

[0095] Figure 9 An implant placed in an aneurysm according to a first embodiment is shown, wherein a membrane covers the proximal segment and a separation point is arranged inside the matrix;

[0096] Figure 10 An implant according to a second embodiment is shown during its release within the aneurysm;

[0097] Figure 11 Showing Figure 10 The implant shown is released at a later stage;

[0098] Figure 12 An implant comprising a tulip-shaped substrate according to a second embodiment is depicted.

[0099] Figure 13 It shows the insertion of another occluder into Figure 12 In the implant shown;

[0100] Figure 14 The electrolytically corroded separation point used to sever the implant is shown;

[0101] Figure 15 This shows another electrolytically corroded separation point used to sever the implant;

[0102] Figure 16 The mechanically releaseable, friction-fit-based disengagement point for releasing the implant is shown;

[0103] Figure 17 It is used for release Figure 16 An enlarged view of the mechanically releasable separation point of the implant shown.

[0104] Figure 18 A further example of a mechanically releasable separation point based on frictional attachment is shown;

[0105] Figure 19 The insertion aid is shown in the form of a flexible tube;

[0106] Figure 20 The diagram shows a shape-closed, mechanically releasable disengagement point for releasing the implant;

[0107] Figure 21 Another shape-closed, mechanically releasable disengagement point for releasing the implant is shown;

[0108] Figure 22 An implant with a two-part insertion aid is shown;

[0109] Figure 23 Another implant with a two-part insertion aid is shown;

[0110] Figure 24 This is an oblique view of another variation of the separation point for separating implants in a closed state, based on shape closure.

[0111] Figure 25 It is from the closed state Figure 24 A side view of the separation point.

[0112] Figure 26 It is in the open state from Figure 24 A perspective view of the separation point.

[0113] Figure 27 A separation element with a shape-fit connection between the insertion aid and the implant is shown, which allows for electrolytic decomposition;

[0114] Figure 28 Showing from Figure 27 Individual components of the separate elements;

[0115] Figure 29 Showing Figure 27 Different perspective views of the separated elements depicted in the figure;

[0116] Figure 30 yes Figure 27 An exploded view of the interlocking components of the separating element, and

[0117] Figure 31 Showing the use Figure 27 The separation element shown is used for implant separation. Detailed Implementation

[0118] Figure 1 This is a schematic diagram of the invention according to a first embodiment, shown as a side view. An implant 1 has been placed in an aneurysm 2, indicated by dashed lines. The implant 1 has a base 6, which consists of a proximal segment 7, a distal segment 8, and a connecting strut 9, the two segments being connected by the connecting strut 9.

[0119] The proximal segment 7 is covered by a membrane 12. Both the proximal segment 7 and the distal segment 8 are made of frame struts 10, which form individual meshes or rings 11. In the proximal segment 7, the frame struts 10 are embedded in the membrane 12. The connecting struts 9 have a curved shape, which ensures that the implant 1 can adapt well to the corresponding conditions of the aneurysm 2 in both the axial and radial directions. This flexibility is further enhanced by the region 14 in the distal segment 8 where there are no frame struts 10.

[0120] In the proximal region, the implant 1 is connected to the insertion aid 5 via a separation point 4, which consists of insertion wires. For example, the separation point 4 can be designed to be electrolytically separable, allowing the implant 1 to be separated after it has been successfully placed in the aneurysm 2.

[0121] exist Figure 2 In the image, implant 1 is shown according to the cross-section. Figure XX Viewed from the distance. Individual rings 11 formed by the frame struts 10 can be seen, covered by a membrane 12. The membrane 12 regulates blood flow and causes the aneurysm 2 to be largely cut off from blood flow.

[0122] Figure 3 This is a side view of a first embodiment of the implant 1 proposed in this invention. The implant 1 also has a distal segment 8 and a proximal segment 7, which are connected to each other by a connecting strut 9. The connecting strut 9 extends in a curve. The proximal segment 7 is covered by a membrane 12. Further proximally, the implant 1 is connected to the insertion aid 5 via a separation point 4.

[0123] Figure 4 The illustrations and Figure 3 The diagram in the image roughly corresponds to this, but in this case, the separation point 4 is located inside the substrate 6. This ensures that no protruding end of the line is left near the proximal end of the implant 1 after separation.

[0124] exist Figure 5 In the diagram, implant 1 is shown in a fully deployed state. In the current configuration, implant 1 is shown with the proximal segment 7 covered by membrane 12, while the distal segment 8 is not covered by membrane. The separation point 4 is located close to the substrate 6.

[0125] Figure 6 The corresponding implant 1 is shown, which is related to Figure 5 The difference with implant 1 is that the distal segment 8 in this illustration is also provided with a membrane 13. The further covering of implant 1 with membrane 13 provides the advantage of largely preventing blood from flowing into aneurysm 2 even in the event of endoleak.

[0126] Figure 7 The corresponding implant 1 placed in aneurysm 2 is shown, without a membrane. This implant 1, designed in this way, serves as a support structure to retain any additional occlusion device introduced into aneurysm 2.

[0127] Figure 8 To a large extent correspond to Figure 7 But with Figure 7 Unlike other implants, the separation point 4 is located inside the base 6. Therefore, a central indentation / inward bending portion is created in the base 6, thereby preventing part of the implant 1 from protruding into the main blood vessel 15.

[0128] exist Figure 9 Another implant 1 is shown, having a separation point 4 disposed within a matrix 6, wherein the proximal segment 7 is covered by a membrane 12. Therefore, implant 1 largely corresponds to... Figure 5The implants are arranged with different separation points 4.

[0129] exist Figure 10 The diagram illustrates a second embodiment of the inventive implant 1, which, upon expansion, takes on the shape of a tulip. The implant 1 is introduced into the aneurysm 2 via a microcatheter 3 through a blood vessel 15 and is released by advancing the implant 1 or retracting the microcatheter 3. In the state shown here, only the distal segment 8 of the implant 1 has expanded, while the proximal region of the implant 1 remains within the microcatheter 3.

[0130] exist Figure 11 middle, Figure 10 The release of implant 1 shown is in a later stage. Separation point 4 can be seen, but it is still located within microcatheter 3.

[0131] Figure 12 A side view of the implant according to the second embodiment is shown. The implant 1 consists of partially interconnected struts 16 forming a mesh-like gap 11 between them. The implant 1 includes a plurality of petal-shaped segments 17 extending from the proximal end of the implant 1, initially radially outward and slightly proximal, and then further distally and radially inward. In this way, the petal-shaped segments 17 are closely abutting the inner wall of the aneurysm 2. The central region 14 remains without struts 16 at the distal end of the implant 1, thereby creating an opening whose size can be larger or smaller depending on the required size of the aneurysm 2.

[0132] Proximally, a separate strut 16 of the implant 1 is connected to a dissociation element 18, which is arranged in a ring around the insertion aid 5. The insertion aid 5 is tubular in design and has a lumen through which a further occlusion device can be introduced into the implant 1. Release of the implant 1 can be achieved by subjecting the ring dissociation element 18 to electrolytic corrosion. Specifically, the implant 1 can initially be inserted into the aneurysm 2, causing it to dilate without any release occurring at the dissociation element 18. A further occlusion device can then be introduced through the insertion aid 5 to fill the internal space of the implant 1. Subsequently, when this process is complete, an electric current is applied to the ring dissociation element 18 to release the implant 1. Finally, the insertion aid 5 and the microcatheter 3 (not shown) are retracted proximally and removed from the vascular system.

[0133] Figure 13 This illustrates how an additional occlusion device 19 is introduced into the internal space of the implant 1 via the insertion aid 5. The implant 1 corresponds to... Figure 12 The implant shown is illustrated, but presented in a simplified form. By retracting the microcatheter 3, the implant 1 has been expanded within the aneurysm 2, causing the strut 16 of the implant 1 to be positioned against the inner wall of the aneurysm 2. However, separation of the implant 1 has not yet occurred.

[0134] Figure 14 and 15 Different methods of electrolytically separating implant 1 are shown. In both cases, an annular separating element 18 is arranged around the tubular insertion aid 5, which is connected to the proximal end of implant 1; this is only implied here. Current can be transmitted through a ( Figure 14 ) or two ( Figure 15 A conductive separation line 20 is applied to the separation element 18, which enables electrolytic corrosion, leading to the separation and eventual release of the implant 1. The separation line 20 is properly insulated so that current is applied to the separation point in a precisely targeted manner. Alternatively, the separation line 20 may extend through the cavity of the insertion aid 5, or a metal mesh of the conduit-like insertion aid may be used as a suitable conductor.

[0135] exist Figure 16 and 17 The image shows a detachable connection between the implant 1 and the insertion aid 5, based on frictional engagement. A radial protrusion 21, in the form of an elastic pad, is arranged around the internally hollow insertion aid 5. The proximal end 23 of the implant 1, in this case comprising a separate strut projecting proximal to the implant 1, has a spherical thickening 22 and is sandwiched between the microcatheter 3 and the insertion aid 5. The interaction of the microcatheter 3, the insertion aid 5, the proximal end 23 of the implant 1, and particularly the radial protrusion 21 and the thickening 22, results in the establishment of a frictional connection and prevents premature dissociation of the implant 1.

[0136] Figure 17 The principle is illustrated in detail. Once the microcatheter 3 is retracted proximally (top left of this diagram), the proximal end 23 of the implant 1 can expand radially, causing the implant 1 to separate. To allow the treating physician to examine the separation process, additional radiopaque markings 24 are provided on the microcatheter 3.

[0137] Figure 18 Images a, b, and c show other mechanically separable separation points based on friction locking, where a combination of friction locking and shape-closure locking is achieved by a suitable thickening 22 disposed at the proximal end 23 of the implant 1. The thickening 22 of the proximal end 23 of the implant 1 is disposed between the radial protrusions 21 of the insertion aid 5, and vice versa. In each case, a microcatheter 3 (not shown) surrounds the device and prevents the proximal end 23 from expanding in the radial direction. Therefore, the implant 1 will not separate until the microcatheter 3 has retracted proximally.

[0138] exist Figure 19The diagram shows a tubular insertion aid 5 with radial protrusions 21 arranged thereon to create a frictional connection. Furthermore, various slits 25 are provided in the insertion aid 5, which increase flexibility and facilitate the advancement of the implant 1 through the microcatheter 3, particularly in narrow blood vessels.

[0139] Figure 20 The proximal end 23 of the implant 1 is depicted as closed and secured. A closed disengagement element 26 is disposed at the proximal end 23, engaging in a corresponding recess 27 in the insertion aid 5. When the microcatheter 3 retracts in the proximal direction, the closed disengagement element 26 can expand radially and exit the recess 27, resulting in the release of the implant 1. To make the retraction process of the microcatheter 3 visible, the catheter is also provided with radiopaque markers 24.

[0140] Figure 21 Another example of a closed-shape separating element 26 is shown, wherein the separating element 26 is shaped like a circular segment and is designed to fit into a corresponding recess 27 provided in the insertion aid 5. When the microcatheter 3 is retracted, as indicated by the arrow, the separating element 26 can exit the recess 27.

[0141] exist Figure 22 and 23 The diagram shows that the insertion aid 5 can consist of two parts. Figure 22 and 23 They are basically the same, but Figure 22 It shows the separation of closed shapes, while Figure 23 The frictional separation described above is shown. The insertion aid 5 with a lumen is formed more rigidly in the proximal portion 28 than in the more flexible distal portion 29. For this purpose, the distal portion 29 has a helical structure in the form of two layers of highly flexible hollow stranded wire. In order to also be able to transmit torsional forces, the helical structures are oriented in opposite directions.

[0142] Figure 24 Another variation is depicted for securing the implant 1 to the insertion aid 5 via a shape-closure connection, wherein at least one disengagement element 31 extends proximally from the proximal end of the implant 1 and is held in a shape-closure manner by a retaining element 30 disposed on the insertion aid 5, the retaining element thus engaging around the disengagement element 31. The disengagement element 31 has a spherical shape. The retaining element 30 is made of a material with shape memory properties. A microcatheter 3, not shown here, is arranged around the retaining element 30 in the closed state and prevents the latter from exhibiting an expanded second structure and releasing the disengagement element 31. Figure 25 This is a side view of the same situation.

[0143] Figure 26This shows the microcatheter 3 after it has retracted proximally. The retaining element 30 is in a pre-defined open second structure, allowing the dissociation element 31 to be withdrawn, which results in the dissociation of the implant 1.

[0144] Figure 27 This illustrates a separation element 46 based on a combination of mechanical shape-locking closure and electrolytic separability. The separation element 46 is shown from the front (a), side (b), and rear (c) portions. The separation element 46 comprises three components: an insertion aid end piece 32 located at the distal end of an insertion aid (not shown); an implant end piece 33 located at the proximal end of an implant (not shown); and an insulating element 34 that electrically separates the insertion aid end piece 32 and the implant end piece 33 from each other, even when they are engaged. The insertion aid end piece 32 and the implant end piece 33 overlap, i.e., the distal region of the insertion aid end piece 32 is distal to the proximal region of the implant end piece 33.

[0145] exist Figure 28 The individual components of the separating element 46 are shown from the front (a), side (b), and rear (c). The insertion auxiliary end piece 32 includes a first short tubular member 35 that is radially closed. This is connected to a second short tubular member 37 having a radial break 38 via a connecting web 36.

[0146] The implant end piece 33 has almost the same structure, namely, it has a radially closed first short tubular element 39, a second short tubular element 41 with a radially provided interruption 42, and a connecting web 40 disposed between the two. However, the positions of the insertion aid end piece 32 and the implant end piece 33 are reversed, that is, the second tubular elements 37 and 41 with interruptions 38 and 42 face each other, wherein the interruptions 38 and 42 are offset by 180°.

[0147] The insulating element 34 has a proximal portion 44 and a distal portion 45. The second tubular element 37 of the insertion aid end piece 32 engages with and surrounds the distal portion 45, while the second tubular element 41 of the implant end piece 33 engages with and surrounds the proximal portion 44. In this configuration, recesses present in the proximal and distal portions 44, 45 are aligned with the second tubular elements 37, 41, i.e., the recesses are completely or substantially filled by them. In this way, the insertion aid end piece 32 and the implant end piece 33 are interlocked with each other, but the area of ​​the insulating element 34 is always arranged between them, such that the voltage applied to the insertion aid end piece 32 is not transmitted to the implant end piece 33, resulting in the two end pieces 32, 33 being insulated from each other.

[0148] Equally important is the electrolytically corroded separation point 43, which dissolves upon application of current, causing separation at this point. The implant is thus released along with the still-attached portion of the separation element 46, while the first tubular element 35 of the insertion aid end piece 32, located proximally, remains on the insertion aid and retracts along with it in the proximal direction. The separation point 43 is the narrow connection point between the first tubular element 35 and the connecting web 36.

[0149] Figure 29 The separating element 46, with its interconnected insertion aid end piece 32, implant end piece 33, and insulating element 34, is shown from different perspectives. It can be seen how the insertion aid end piece 32 and implant end piece 33 engage with each other in a shape-closed manner, but the area of ​​the insulating element 34 always prevents direct contact between the insertion aid end piece 32 and implant end piece 33. Furthermore, it can be seen that the cavity of the separating element 46 is provided for connection to a tubular or flexible insertion aid. Therefore, this allows additional occlusion devices such as coils or embolic agents to be introduced into the aneurysm.

[0150] Figure 30 This is an exploded view of the separating element 46, showing that the second tubular elements 37 and 41 of the insertion end piece 32 and the implant end piece 33—both of which are provided with interruptions—overlap each other, with the insulating element 34 located between them. The interruptions 38 and 42 in the end pieces 32 and 33 and the recesses in the insulating element 34 designed to fit into the second tubular elements 37 and 41 are both offset radially by 180°.

[0151] at last, Figure 31 The dissociation of the implant at the dissociation element 46 is shown. Current is applied to the dissociation point 43 via the insertion aid and the metal insertion aid end piece 32, which is connected as the anode. This arrangement causes the corrosively designed dissociation point 43 to dissolve, and the proximal region of the insertion aid end piece 32 disconnects from the rest of the dissociation element 46. The latter is released along with the implant, while the proximal portion of the insertion aid end piece can retract proximally and be removed from the vascular system. The metal portion of the dissociation element 46 remaining on the implant can be made, for example, of magnesium, which dissolves over time, resulting in the removal of unwanted foreign matter. The dissociation element 46 ensures a strong shape-closure connection between the insertion aid and the implant, keeping the implant in place even if the surrounding microcatheter retracts proximally, causing the dissociation element 46 to be released. Release of the implant is not caused until voltage is applied to the dissociation point 43. Furthermore, the shape-closure connection between the insertion aid and the implant also allows for the transmission of torsional motion.

[0152] The present invention also discloses the following embodiments:

[0153] 1. An implant for treating arteriovenous malformations, particularly aneurysms (2), wherein the implant (1) is capable of being delivered in a compressed state to a target site in a patient's vascular system via a microcatheter (3), wherein the implant (1) is pre-configured as a second structure that causes the implant to be in an expanded state upon release from the microcatheter (3), wherein the implant (1) is detachably connected to an insertion aid (5) at a separation point (4), wherein the implant (1) in the expanded state has a base (6) comprising a proximal segment and a distal segment (7, 8) having a dome-shaped construction, the convex side of the dome of the proximal segment (7) facing the proximal direction, and the convex side of the dome of the distal segment (8) facing the distal direction, and wherein the proximal segment and the distal segment (7, 8) are interconnected by a plurality of connecting struts (9).

[0154] 2. The implant according to Example 1, wherein the connecting strut (9) arranged between the proximal and distal segments (7, 8) is curved.

[0155] 3. The implant according to Example 1 or 2, wherein the proximal segment and / or distal segment (7, 8) are composed of frame struts (10) that are at least partially connected to each other.

[0156] 4. The implant according to Example 3, wherein, in the expanded state, the frame strut (10) forms a mesh or ring structure (11) in the proximal and / or distal segments (7, 8).

[0157] 5. The implant according to embodiment 3 or 4, wherein the distal segment (8) preferably includes a region (14) without a frame strut (10) in a central location, the region (14) being expandable and compressible.

[0158] 6. The implant according to any one of Examples 1 to 5, wherein the proximal segment (7) is provided with a membrane (12) that at least partially covers the proximal segment (7).

[0159] 7. The implant according to Example 6, wherein the distal segment (8) is provided with a membrane (13) that at least partially covers the distal segment (8).

[0160] 8. The implant according to Example 6 or 7, wherein the connecting strut (9) is at least partially covered with a membrane.

[0161] 9. An implant for treating arteriovenous malformations, particularly aneurysms (2), wherein the implant (1) is capable of being guided to a destination in a patient's vascular system via a microcatheter (3) in a compressed state, and the implant (1) is pre-configured as a second structure that causes the implant to be in an expanded state upon release from the microcatheter (3), wherein the implant (1) is detachably connected to an insertion aid (5) via a separation point (4), and in the expanded state has a base (6) consisting of struts (16), wherein the struts (16) are at least partially interconnected at intersection points to form a gap (11) between the struts (16), wherein the struts (16) extend radially outward at the proximal end of the base (6) in the expanded state, and further extend axially and radially inward in a distal direction to create a protrusion of the base (6), wherein the base (6) has a region at the distal end where the struts (16) are not interconnected with each other.

[0162] 10. The implant according to Example 9, wherein the base (6) in the expanded state has an opening (14) at the distal end.

[0163] 11. The implant according to any one of Examples 1 to 10, wherein the substrate (6) in the expanded state is approximately spherical, ellipsoidal, oval, tulip-shaped or cylindrical with a convex outwardly curved base surface.

[0164] 12. The implant according to any one of Examples 1 to 11, wherein when the base (6) is in the expanded state, the distal end of the insertion aid (5) is located inside the base (6).

[0165] 13. The implant according to any one of Examples 1 to 12, wherein the insertion aid (5) has a tubular or flexible design and has a lumen.

[0166] 14. The implant according to Example 13, wherein the tubular or flexible insertion aid (5) protrudes beyond the separation point (4) in the distal direction.

[0167] 15. The implant according to any one of Examples 1 to 13, wherein a separation element (18) is disposed outside the insertion aid (5), the element being connected to the proximal end (23) of the implant (1), wherein the implant (1) can be released by applying a voltage to the separation element (18).

[0168] 16. The implant according to embodiment 15, wherein the separation element (18) is arranged circumferentially around the insertion aid (5).

[0169] 17. The implant according to any one of Examples 1 to 14, wherein the insertion aid (5) has a radial protrusion (21) at its distal end on the outer side and extends into the implant (1) together with the distal end, such that a frictional connection is provided between the insertion aid (5), the implant (1), and the microcatheter (3) or a sheath surrounding the distal end of the insertion aid (5), wherein the implant (1) is released by movement of the microcatheter (3) or the sheath relative to the implant (1) and the insertion aid in the proximal direction.

[0170] 18. The implant according to Example 17, wherein the radial protrusion (21) is made of an elastic material.

[0171] 19. The implant according to embodiment 13 or 14, wherein a separation element (26) is disposed at the proximal end of the implant (1), the separation element engaging in a shape-closed manner in a recess (27) provided in a tubular or flexible insertion aid (5) for this purpose, so that separation of the implant (1) occurs by movement of the microcatheter (3) or a sheath surrounding the distal end of the insertion aid (5) relative to the implant (1) and the insertion aid (5) in the proximal direction.

[0172] 20. The implant according to any one of Embodiments 1 to 14, wherein at least one separating element (31) extends in a proximal direction at the proximal end of the implant (1), the element being secured in a form-closed manner by a retaining element (30) disposed on the insertion aid (5), wherein the retaining element (30) is made of a material having shape memory properties and the retaining element (30) is preset to a second structure, wherein the separating element (31) is released and separation of the implant (1) occurs when the second structure is presented, wherein the retaining element (30) is prevented from presenting the second structure by a surrounding microcatheter (3) or another sheath surrounding the retaining element (30).

[0173] 21. The implant according to any one of Embodiments 1 to 14, wherein an insertion aid end piece (32) is disposed at the distal end of the insertion aid (5), the end piece having an electrolytically corroded separation point (43), wherein the insertion aid end piece (32) is connected in a shape-closed manner to an implant end piece (33) disposed at the proximal end of the implant (1), and wherein an insulating element (34) is disposed between the insertion aid end piece (32) and the implant end piece (33) to avoid direct contact between the insertion aid end piece (32) and the implant end piece (33).

[0174] 22. The implant according to embodiment 21, wherein the insertion aid end piece (32) and the implant end piece (33) each have a first tubular element (35, 39) and a second tubular element (37, 41), a connecting abdominal plate (36, 40) is disposed between each of the first tubular elements (35, 39) and the second tubular elements (37, 41), and each of the second tubular elements (37, 41) has a radial interruption (38, 42), wherein the insertion aid end piece (32) and the implant end piece (33) are connected together such that the second tubular element (41) of the implant end piece (33) is arranged proximal to the second tubular element (37) of the insertion aid end piece (33).

Claims

1. An implant for treating arteriovenous malformations, wherein, The implant is capable of being guided to its destination in the patient's vascular system via a microcatheter in a compressed state, and the implant is pre-configured with a second structure that allows the implant to be in an expanded state upon release from the microcatheter. The implant is detachably connected to an insertion aid via a first separation point and, in the expanded state, has a base composed of struts. Its features are, The struts are at least partially interconnected at their intersection points, thereby forming a gap between the struts, wherein the struts form a plurality of individual segments converging at the proximal end of the struts, the plurality of individual segments being configured to adapt to the inner wall of the arteriovenous malformation, wherein the struts extend radially outward at the proximal end of the base in an expanded state, and further extend axially and radially inward in a distal direction, thereby creating a protrusion of the base, wherein the base has a region at the distal end where the struts are not connected to each other.

2. The implant according to claim 1, characterized in that, The arteriovenous malformation mentioned is an aneurysm.

3. The implant according to claim 1 or 2, characterized in that, The substrate in the expanded state has an opening at the distal end.

4. The implant according to claim 1, characterized in that, The matrix in the expanded state is approximately spherical, ellipsoidal, oval, tulip-shaped, or cylindrical with a convex, outwardly curved base surface.

5. The implant according to claim 1, characterized in that, When the substrate is in the expanded state, the distal end of the insertion aid is located inside the substrate.

6. The implant according to claim 1, characterized in that, The insertion aid has a tubular design and an inner lumen.

7. The implant according to claim 6, characterized in that, The insertion aid, having the tubular design, protrudes beyond the first separation point in the distal direction.

8. The implant according to claim 1, characterized in that, A first separation element is disposed on the outside of the insertion aid and is connected to the proximal end of the implant, wherein the implant can be released by applying a voltage to the first separation element.

9. The implant according to claim 8, characterized in that, The first separating element is arranged in a ring around the insertion aid.

10. The implant according to claim 1, characterized in that, The insertion aid has a radially projecting distal end on the outer side and extends into the implant together with the distal end, such that a frictional connection is provided between the insertion aid, the implant, and the microcatheter or a sheath surrounding the distal end of the insertion aid, wherein the implant is released by movement of the microcatheter or sheath relative to the implant and the insertion aid in the proximal direction.

11. The implant according to claim 10, characterized in that, The radial protrusions are made of an elastic material.

12. The implant according to claim 6, characterized in that, The second separation element is disposed at the proximal end of the implant and engages in a shape-closed manner in a recess provided in an insertion aid having a tubular design for this purpose, so that separation of the implant occurs by movement of the microcatheter or a sheath surrounding the distal end of the insertion aid relative to the implant and the insertion aid in the proximal direction.

13. The implant according to claim 1, characterized in that, At least one third separation element extends proximally at the proximal end of the implant, the at least one third separation element being secured in a form-closed manner by a retaining element disposed on the insertion aid, wherein the retaining element is made of a material having shape memory properties and the retaining element is preset to a second structure, wherein the at least one third separation element is released and separation of the implant occurs when the second structure is presented, wherein the retaining element is prevented from presenting the second structure by a surrounding microcatheter or another sheath surrounding the retaining element.

14. The implant according to claim 1, characterized in that, An insertion aid end piece is disposed at the distal end of the insertion aid, the insertion aid end piece having a second separation point that can be electrolytically etched, wherein the insertion aid end piece is connected in a shape-closed manner to an implant end piece disposed at the proximal end of the implant, and wherein an insulating element is disposed between the insertion aid end piece and the implant end piece to avoid direct contact between the insertion aid end piece and the implant end piece.

15. The implant according to claim 14, characterized in that, The insertion aid end piece and the implant end piece each have a first tubular element and a second tubular element, a connecting web is disposed between the respective first tubular elements and the second tubular elements, and the second tubular elements each have a radial interruption, wherein the insertion aid end piece and the implant end piece are connected together such that the second tubular element of the implant end piece is arranged proximal to the second tubular element of the insertion aid end piece.

16. The implant according to claim 1, characterized in that, The insertion aid has a flexible tube design and an inner lumen.

17. The implant according to claim 16, characterized in that, The insertion aid, having the design of the aforementioned flexible tube, protrudes beyond the first separation point in the distal direction.

18. The implant according to claim 16, characterized in that, The second separation element is disposed at the proximal end of the implant and engages in a shape-closed manner in a recess provided in an insertion aid with a tubular design for this purpose, so that separation of the implant occurs by movement of the microcatheter or a sheath surrounding the distal end of the insertion aid relative to the implant and the insertion aid in the proximal direction.

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