Medical implant, and method for producing a medical implant
The medical implant addresses thrombogenicity and blood flow issues by using a support body with adjustable porosities and filament density to minimize metal content, effectively treating vascular lesions while maintaining blood flow to branching vessels.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- ACANDIS GMBH & CO KG
- Filing Date
- 2025-12-09
- Publication Date
- 2026-06-25
Smart Images
Figure EP2025085977_25062026_PF_FP_ABST
Abstract
Description
[0001] Acandis GmbH December 9, 2025 M / CAN-431-PC JK / AS / pk
[0002] Medical implant; method for manufacturing a medical implant
[0003] Description
[0004] The invention relates to a medical implant for treating a local lesion in a vessel, in particular for treating a bifurcation aneurysm, comprising a support body that is compressible and expandable. A medical implant according to the preamble of claim 1 is known, for example, from DE 10 2012 112 730 A1, which is attributed to the applicant. The invention further relates to a method for manufacturing such a medical implant.
[0005] To treat vascular lesions such as aneurysms, medical implants, such as flow diverters, are used to reduce blood flow into the lesion, allowing the blood within the lesion to coagulate, possibly with the aid of an embolic agent. Due to the implant's position within the vessel, particularly at a bifurcation, blood flow into a branching vessel may be restricted. This can lead to an insufficient supply of nutrients to the downstream tissue areas.
[0006] For example, EP 3 244 843 A discloses a treatment system for bifurcation aneurysms in which at least two implants are inserted in the region of a bifurcation to treat the aneurysm and largely maintain blood flow into a branching vessel. However, the arrangement of multiple implants in the vessel presents significant disadvantages with regard to the thrombogenicity of the treatment system.
[0007] From the aforementioned DE 10 2012 112 730 A, an implant with a braided support body is also known, designed to reduce blood flow into a lesion. Although the known implant already functions very well, there is potential for improvement regarding the implant's thrombogenicity. M / CAN-431-PC
[0008] 2
[0009] Furthermore, US 2009 / 0306762 Al, WO 2005 / 065579 Al, and US 2008 / 0288054 Al describe medical implants for aneurysm treatment that can at least largely divert blood flow away from an aneurysm. However, the risk of thrombus formation is increased with these known implants.
[0010] The invention is therefore based on the objective of providing a medical implant for the treatment of a vascular lesion, which reduces the risk of thrombus formation. Furthermore, the invention is based on the objective of providing a method for manufacturing such an implant.
[0011] According to the invention, this problem is solved by a medical implant having the features of claim 1. With regard to the method, this problem is solved by the subject matter of claim 16.
[0012] Specifically, the problem is solved by a medical implant for treating a local lesion in a vessel, in particular for treating a bifurcation aneurysm, with a radially compressible and expandable support body. The support body has at least one support mesh and one densification mesh, each formed by interwoven filaments. The densification mesh is woven into the support mesh in such a way that at least one densified area with a first porosity and at least one support area with a second porosity, which is free with respect to the densification mesh, is formed. The ratio of the first porosity to the second porosity is between 1:1.15 and 1:2, in particular between 1:1.2 and 1:2, in particular between 1:1.4 and 1:2, in particular between 1:1.6 and 1:2, and in particular between 1:1.8 and 1:2.
[0013] The medical implant or support structure has a network of filaments, in particular a tubular wall made of filaments. The porosity preferably describes the ratio of the projected surface area of the filaments to the total surface area of the support structure.
[0014] The invention has several advantages. M / CAN-431-PC
[0015] 3
[0016] The thrombogenicity of the implant can be reduced by the support body design according to the invention. In other words, the risk of thrombus formation can be reduced by the support body design according to the invention. This is advantageously achieved by ensuring that the number of filaments in the support body is sufficiently large, preferably in only one section or in selected sections, to treat a lesion. The filaments are preferably arranged so closely together in selected sections that the blood flow from a lesion can be diverted, at least to a large extent. Advantageously, the arrangement of the filaments is adjustable such that a lesion can be treated efficiently without significantly affecting the thrombogenicity of the implant.
[0017] The filaments of the support body are preferably designed as DFT wires with a radiopaque core sheathed in a superelastic material, particularly nitinol. Generally, the risk of thrombus formation increases with the amount of metal in the support body. By ensuring that the number of filaments is sufficiently high to treat a lesion only in selected sections of the support body, the total amount of metal is reduced. Furthermore, this reduces the proportion of filaments to the total surface area of the support body, thereby lowering the risk of thrombus formation.
[0018] According to the invention, the support body is formed from a support mesh into which a densification mesh is woven, at least partially. The densification mesh is preferably formed by additional filaments that are woven only into that area of the support mesh which, in the implanted state, is intended to reduce blood flow into a lesion. By weaving in additional filaments, or by weaving the densification mesh into preferably a section of the support body, a densified area is formed that is sufficiently impermeable to blood to reduce blood flow into a lesion. By limiting the additional filaments to a selected area of the support body, the amount of metal in the support body can be reduced, thereby decreasing the risk of thrombus formation. M / CAN-431-PC
[0019] 4
[0020] Those sections of the support body that comprise only the support mesh are preferably free of the compression mesh. These sections of the support body preferably form support areas designed to provide a sufficiently high support force to anchor the implant in the vessel.
[0021] Preferably, two support areas are provided, separated from each other by the compacted area. In other words, the support body can have two support areas located proximal and distal to the compaction mesh. It is also possible for the support body to have multiple compacted areas or multiple compaction meshes, each separated from the others by a support area.
[0022] The at least one densified area has a first porosity, and the at least one support area has a second porosity. The first porosity is lower than the second porosity, or the second porosity is higher than the first porosity. This is achieved, among other things, by preferably having a larger number of filaments in the area of the first porosity than in the area of the second porosity. Furthermore, the proportion of filaments to the total surface area is preferably higher in the area of the first porosity than in the area of the second porosity. In the area of the first porosity, the densification mesh is preferably interwoven with the support mesh to increase the number of filaments.
[0023] A ratio of first porosity to second porosity between 1:1.15 and 1:2 has proven particularly advantageous in order to achieve, on the one hand, a sufficiently high support force in the support area and, on the other hand, a sufficient blood density in the compacted area, whereby both functions can be fulfilled without significantly affecting the thrombogenicity of the implant.
[0024] The inventive ratio between the first and second porosities allows for a reduction in the amount of metal in the support body, since only the first porosity contains a sufficient number of filaments to treat a lesion. The second porosity preferably contains only as many filaments as are necessary to achieve sufficient support for the implant. This saving of filaments in the area of the M / CAN-431-PC
[0025] The second porosity advantageously reduces the thrombogenicity of the implant.
[0026] In particular, the ratio of the first porosity to the second porosity can be between 1:1.2 and 1:2, in particular between 1:1.3 and 1:2, in particular between 1:1.4 and 1:2, in particular between 1:1.5 and 1:2, in particular between 1:1.6 and 1:2, in particular between 1:1.7 and 1:2, in particular between 1:1.8 and 1:2, in particular between 1:1.9 and 1:2.
[0027] Furthermore, the medical implant according to the invention enables efficient treatment of a local lesion without significantly affecting blood flow into an outgoing vessel near the lesion. For this purpose, the implant's supporting body is designed such that both functions can be fulfilled.
[0028] For this purpose, the supporting body has at least the compacted area with the first porosity and at least the support area with the second porosity.
[0029] While the lower, primary porosity of the densified area in the implanted state serves to divert blood flow away from the lesion, the larger, secondary porosity of the supporting area ensures that blood flow into offshoot vessels located near the lesion is largely preserved. In other words, the primary porosity is sufficiently blood-impermeable to reduce blood flow into the lesion, and the secondary porosity is sufficiently blood-permeable to maintain blood flow into the offshoot vessel.
[0030] The arrangement and length of the first and second porosities, or of the at least one densified area and the at least one support area along the longitudinal axis of the support body, as well as the size of the first and second porosities, are adjustable such that both functions—i.e., diverting blood flow away from the lesion and maintaining blood flow into an outgoing vessel—can be fulfilled. This allows the implant to be adapted to different vascular anatomies.
[0031] In particular, the medical implant is suitable for treating lesions located at or near a bifurcation. Such a bifurcation can include at least one main vessel and at least two branching tributaries. The densification network or densified area of the implant can be positioned in one of the tributaries. M / CAN-431-PC
[0032] 6. The support section should be positioned so that the aneurysm is at least partially covered and blood flow into the aneurysm through the first porosity is reduced. The support section can be positioned in the main vessel of the bifurcation such that it spans the other tributary vessel, while maintaining blood flow into the tributary vessel through the second porosity.
[0033] For example, the implant can be placed in a bifurcation where the branches leading from the main vessel each form an angle between 20° and 110° with the main vessel. In other words, the medical implant can be flexible enough to be positioned in a bifurcation with a vessel angle between 20° and 110°. It is also conceivable that the implant could be positioned in a vessel without branches that forms an angle between 20° and 110°.
[0034] The implant's support body is preferably substantially tubular in shape. In particular, the support body is substantially tubular in its manufactured state. The support body is preferably tubular in such a way that, in the implanted state, it allows for adaptation to a vessel wall. The tubular shape may also include a conical form. Furthermore, it may include bulges (barrels) or flared longitudinal ends. Preferably, the support body is at least partially cylindrical.
[0035] Preferred embodiments of the invention are specified in the dependent claims.
[0036] For example, the initial porosity, i.e., the porosity of the densified area, can be between 45% and 65%, particularly at most 60%, particularly at most 55%, and particularly at most 50%. Such a porosity is particularly well suited to reducing blood flow into a lesion in the implanted state.
[0037] Furthermore, the second porosity, i.e., the porosity of the support area, can be between 75% and 90%, in particular at least 80%, and in particular at least 85%. Such a porosity is advantageously particularly well suited for M / CAN-431-PC.
[0038] 7. To maintain blood flow into branching vessels in the implanted state.
[0039] Preferably, the filaments of the support mesh and the compaction mesh each form meshes. The at least one support area preferably has a larger mesh size than the at least one compaction area. Advantageously, the porosity can be changed or influenced by the mesh size. Consequently, the first and second porosities can be easily changed by the mesh size. For example, the mesh size can be adjusted by the number of filaments.
[0040] The at least one support area preferably has a mesh size between 0.2 mm and 1.5 mm, in particular at least 0.4 mm, in particular at least 0.6 mm, in particular at least 0.8 mm, in particular at least 1 mm, in particular at least 1.2 mm. This advantageously allows sufficient blood permeability to be achieved so that blood flow into an outgoing vessel can be maintained. Furthermore, this allows the outgoing vessel to be accessed through the mesh with a treatment device, for example a catheter, in particular a 2 French catheter.
[0041] In an advantageous embodiment, the compaction mesh is arranged in a central longitudinal section of the support body such that a proximal and / or a distal longitudinal section of the support body is unobstructed with respect to the compaction mesh. The compacted area, i.e., the area in which the compaction mesh is woven into the support mesh, is preferably overlaid on both sides by the support mesh. The support mesh can have a length greater than the length of the compaction mesh. The first or second mesh edge of the support mesh and the compaction mesh are spaced apart from each other in the longitudinal direction of the implant. In particular, the first mesh edge of the support mesh can be spaced apart from the first mesh edge of the compaction mesh, and / or the second mesh edge of the support mesh can be spaced apart from the second mesh edge of the compaction mesh.The area of the support mesh that extends above the compaction mesh, i.e., the sections of the support body that only contain the support mesh M / CAN-431-PC.
[0042] The 8 sections comprise the support areas. Preferably, two support areas are provided, separated from each other by the compacted area.
[0043] Preferably, the densifying mesh is interwoven into the supporting mesh in such a way that a single-layer wall is formed. The medical implant advantageously comprises a single-layer wall that forms the supporting body. The filaments of the densifying mesh can be interwoven into the supporting mesh in such a way that they are completely integrated into the supporting mesh or the wall of the supporting body. By forming a single-layer wall through the interweaving of the densifying mesh into the supporting mesh, a uniform distribution of forces is achieved across the entire implant surface. This design contributes to improved structural integrity and minimizes the risk of deformation or misplacement.
[0044] Preferably a 1-over-1 braid is used, such that each filament of the compaction braid crosses over every second filament of the support braid and undercrosses every second, intermediate, filament of the support braid.
[0045] Furthermore, the filaments of the support mesh can have a larger diameter than the filaments of the compression mesh. This reduces the influence of the compression mesh filaments on the radial force of the support body in the compressed area. Conversely, a smaller diameter for the compression mesh filaments prevents an increase in the wall thickness of the support body in the compressed area. Using filaments with different diameters in the support and compression meshes improves the strength and flexibility of the implant. The stronger support mesh provides the necessary stability, while the finer compression mesh enhances the flexibility and adaptability of the implant to the anatomical structure of the vessel.
[0046] The filaments of the support mesh preferably have a sufficiently large diameter to provide the necessary support force for secure implant anchorage. By using such a large filament diameter, the number of filaments in the at least one support area, particularly compared to the densified area, can be kept low. This is preferably understood to mean that, despite the M / CAN-431-PC
[0047] 9. With a low number of filaments in the support area, a sufficiently high support force can be achieved if the filament diameter in the support area is sufficiently large. In other words, a reduction in the number of filaments can be compensated for to some extent by increasing the filament diameter with regard to support force. This allows the amount of metal in the support area and thus the thrombogenicity of the entire implant to be reduced.
[0048] The ratio between the diameter of the filaments of the compaction mesh and the diameter of the filaments of the support mesh is preferably at most 1:2, in particular at most 1:2.5, in particular at most 1:2.75, in particular at most 1:3, in particular at most 1:3.5, in particular at most 1:4, in particular at most 1:4.5, in particular at most 1:5.
[0049] For example, the filaments of the supporting mesh have a diameter between 38 pm and 85 pm, in particular at least 40 pm, in particular at least 45 pm, in particular at least 50 pm, in particular at least 55 pm, in particular at least 60 pm, in particular at least 65 pm, in particular at least 70 pm, in particular at least 75 pm, in particular at least 80 pm.
[0050] Furthermore, the filaments of the compaction mesh can have a diameter between 20 pm and 50 pm, in particular at most 45 pm, in particular at most 40 pm, in particular at most 35 pm, in particular at most 30 pm, in particular at most 25 pm.
[0051] The number of filaments in the densified area is preferably at least twice, in particular at least three times, in particular at least four times, in particular at least five times, greater than the number of filaments in the support area. The porosity can be adjusted by the number of filaments. An increase in the number of filaments advantageously leads to a decrease in porosity. Because there are more filaments in the densified area than in the support area, it can be ensured that, on the one hand, the densified area has a sufficient number of filaments to divert blood flow away from a lesion when implanted, and on the other hand, the at least one support area has a sufficient number of filaments.
[0052] 10 shows that the supporting force is sufficient to anchor the implant in the vessel and to maintain blood flow into a branching vessel.
[0053] The supporting mesh can, for example, have 12 to 24, in particular at least 16, in particular at least 20, filaments. The compaction mesh can have 12 to 48, in particular at least 24, filaments.
[0054] If the supporting mesh and the compaction mesh each have 24 filaments, the compacted area is formed from 48 filaments. In this particularly preferred embodiment, the at least one compacted area has twice as many filaments as the at least one supporting area.
[0055] The support mesh and / or the compression mesh preferably form closed loops at their proximal and / or distal longitudinal ends. Particularly preferably, both the support mesh and the compression mesh form closed loops at both longitudinal ends. The closed loops at the proximal and distal longitudinal ends of the support mesh provide increased stability and prevent the implant from slipping. This ensures secure placement within the vessel and minimizes the risk of unintended movement after implantation.
[0056] It is advantageous that the loops generate increased uprighting force at the longitudinal ends of the support body, thereby ensuring secure anchorage of the support body near the lesion. Furthermore, the closed loops preferably create a diameter increase at the longitudinal ends of the support body (flaring). Such radial widening of the longitudinal ends can, for example, reduce the risk of implant migration.
[0057] Furthermore, by forming closed loops at both longitudinal ends of the support mesh, the number of filaments in the support mesh can be further reduced, as the closed loops provide additional support or erection force at the longitudinal ends of the support mesh. This can further reduce the risk of thrombus formation. M / CAN-431-PC
[0058] 11
[0059] Alternatively, the supporting mesh and / or the compaction mesh can form closed loops at one longitudinal end and have open filament ends at the other longitudinal end.
[0060] The filaments of the support mesh and / or the compression mesh may comprise stainless steel or a superelastic metal, in particular nitinol, and / or a plastic material, in particular bioresorbable, and / or an X-ray visible material, in particular platinum.
[0061] Preferably, the filaments are designed such that a radiopaque core material is encased in a shape-memory material. In other words, the surface of the filaments can be made of a shape-memory material. The advantage here is that the implant is self-expanding or exhibits self-expanding properties due to the shape-memory material.
[0062] Preferably, the filaments are formed from an X-ray-visible core material, in particular platinum or a platinum alloy, and a shape-memory material, in particular a nickel-titanium alloy, wherein the core material has a cross-sectional area of between 10% and 50%, in particular between 20% and 30%, of the filament. The proportion of the core material to the cross-sectional area of the filament depends, for example, on the filament diameter or can be adapted to the filament diameter.
[0063] It is advantageous that the filaments exhibit optimal radiolucency due to the core material. This allows, for example, a surgeon to easily determine the implant's position during insertion or once implanted. Platinum or a platinum alloy is particularly preferred as the core material, since these materials offer optimal radiopacity and consequently good radiolucency. As a result, it is unnecessary to use additional marker elements, such as marker sleeves that can be applied or crimped onto the wire. However, the use of additional marker elements is not precluded.
[0064] Such filaments or wires, formed from an X-ray visible core material encased in a shape memory material, are used in the M / CAN-431-PC.
[0065] 12
[0066] Generally known as DFT wires. The filaments of the support braid and / or the compaction braid are particularly preferably designed as DFT wires.
[0067] Preferably, at least one radiopaque marker is positioned at the junction between the densified area and the supporting area. The radiopaque marker ensures optimal radiographic visibility of the implant. This allows for ideal positioning of the implant within the lesion, particularly a bifurcation aneurysm. It makes it easy for the surgeon to estimate where the implant will be placed in the vessel after its release from an introducer.
[0068] Alternatively or additionally, radiopaque end markers can be provided, especially at the closed loops of the implant.
[0069] In a preferred embodiment, the marker elements can be designed as marker sleeves that can be firmly connected to the filament, in particular by crimping them onto the filament. Such marker sleeves exhibit, for example, a higher X-ray density compared to marker coils, resulting in improved X-ray visibility. Crimping the marker sleeves onto the filaments ensures a stable connection between the marker sleeves and the filaments.
[0070] Furthermore, the filaments can have a braiding angle relative to the longitudinal axis of the support body, with the filaments in the densified area having a different braiding angle than the filaments in the support area. The braiding angle is preferably determined by the inclination of the filaments relative to the longitudinal axis of the support body. This is advantageous because the porosity of the support body can be easily adjusted by the braiding angle.
[0071] Preferably, the filaments in the densified area have a larger braid angle than the filaments in the supporting area. Consequently, the densified area preferably has lower porosity than the supporting area. This allows for good coverage of the lesion in the densified area. Furthermore, it allows for the maintenance of blood flow into an outgoing vessel in the supporting area. M / CAN-431-PC
[0072] 13
[0073] The filaments in the support area preferably have a braiding angle between 45° and 60°, particularly at most 55°, and especially at most 50°. Such a braiding angle in the support area is particularly preferred because the secondary porosity can be adjusted in such a way that, on the one hand, good support and thus good anchorage in the vessel can be ensured, and on the other hand, it is ensured that the blood flow into an outgoing vessel is maintained.
[0074] The filaments in the densified area can have a braiding angle between 60° and 80°, in particular at least 75°, in particular at least 70°, in particular at least 65°. Such a braiding angle is particularly preferred because the first porosity in the densified area can be adjusted so that the blood flow can be at least partially diverted away from the lesion.
[0075] The braid angle of the filaments of the support braid and the braid angle of the filaments of the compression braid are preferably the same in the compressed area. This contributes to the fact that a uniform and relatively small crimping force is sufficient to compress the support body.
[0076] In an advantageous embodiment, the at least one densified area has a different cross-sectional diameter than the at least one support area. In particular, the densified area has a larger cross-sectional diameter than the support area. This advantageously ensures that the densified area adapts optimally to the vessel wall in the region of a lesion when implanted.
[0077] Advantageously, each section along the longitudinal axis of the implant can be individually adapted. This allows each section of the implant to have different dimensions, i.e., a different length in the axial direction and / or a different cross-sectional diameter. This enables the implant to be optimally adapted to a patient's vascular anatomy.
[0078] Thus, each section of the implant, for example the at least one compacted area and / or the at least one support area, preferably has a length between 3 mm and 15 mm in the axial direction, in particular at least 5 mm. M / CAN-431-PC
[0079] 14 mm, in particular at least 7 mm, in particular at least 9 mm, in particular at least 11 mm, in particular at least 13 mm.
[0080] Furthermore, each section, for example the at least one compacted area and / or the at least one support area, preferably has a cross-sectional diameter between 2.5 mm and 8 mm, in particular at least 3 mm, in particular at least 4 mm, in particular at least 5 mm, in particular at least 6 mm, in particular at least 7 mm.
[0081] Furthermore, the support body can have a change in cross-sectional diameter in the axial direction, particularly from distal to proximal. The change in cross-sectional diameter in the axial direction can be between 0.5 mm and 2 mm, and in particular at least 1 mm. For example, the support body can have a cross-sectional diameter of 4 mm at a proximal longitudinal end and a cross-sectional diameter of 3 mm at a distal longitudinal end.
[0082] Furthermore, by changing the cross-sectional diameter along the longitudinal axis of the implant, it is possible to create a bulge in the support body. This bulge is preferably located on the section of the implant that covers the aneurysm when implanted. For example, the densified area can include a bulge. Such stents, which feature a bulge, are commonly referred to as barrel stents.
[0083] The support structure can have an antithrombogenic coating, which may include heparin and / or fibrin. In other words, the support structure can be coated with a material that has antithrombogenic properties. The coating can exert an anticoagulant effect, thus favorably influencing the adhesion of blood proteins. A layer of cells, particularly endothelial cells, can then form over the support structure. The support structure material is thus masked by a layer of blood proteins, which also prevents or reduces the deposition of platelets and coagulation proteins, such as fibrinogen, which are primarily responsible for thrombus formation. Overall, this results in a reduction in the tendency for thrombus formation. M / CAN-431-PC
[0084] 15
[0085] The antithrombogenic coating preferably comprises heparin and / or fibrin, with heparin being covalently bound to fibrin.
[0086] According to dependent claim 16, the invention relates to a method for manufacturing the medical implant according to the invention. At least two filaments are helically braided around a common longitudinal axis, forming the support mesh. During the braiding of the filaments of the support mesh, one or more filaments forming a densification mesh are integrally woven into at least one section of the support mesh such that at least one densified area with a first porosity and at least one support area with a second porosity, which is free with respect to the densification mesh, is formed.
[0087] Preferably, the filaments of the support mesh and the compaction mesh are woven such that they form closed loops at one longitudinal end, particularly at the same longitudinal end. Open filament ends are formed at the other longitudinal end of the support mesh and the compaction mesh. Two adjacent open filament ends of the support mesh and the compaction mesh can be joined together, particularly by welding or crimping, to form closed loops. In this way, it can be achieved that the support mesh and the compaction mesh each have closed loops at both longitudinal ends.
[0088] The invention is explained in more detail with reference to exemplary embodiments in connection with the schematic drawing.
[0089] This shows
[0090] Fig. 1 shows an unfolded view of the medical implant according to an embodiment of the invention; and
[0091] Fig. 2 shows an unfolded view of the medical implant according to a further embodiment of the invention. M / CAN-431-PC
[0092] 16
[0093] The same reference numbers are used below for identical or equivalent parts.
[0094] Figures 1 and 2 show an embodiment of a medical implant 10 according to the invention, in particular a stent, for treating a local lesion in a vessel. This example illustrates the application of the implant 10 or the stent 10 for treating a bifurcation aneurysm. Other applications are conceivable. For example, the implant 10 or the stent 10 is generally suitable for treating vascular lesions.
[0095] The implant 10 has a support body 11 that is compressible and expandable. Specifically, the support body 11 is self-expanding. In use, the support body 11 is at least partially tubular in shape.
[0096] Figures 1 and 2 show the support body 11 of the implant 10 in its unfolded or unfolded state for the sake of clarity.
[0097] The support body 11 has at least one support mesh 12 formed by interwoven filaments 20. The filaments 20 of the support mesh 12 are designed as DFT wires.
[0098] Furthermore, the support body 11 has a compaction mesh 13 formed by interwoven filaments 21. The compaction mesh 13 is formed by additional filaments 21 woven into the support mesh 12. The filaments 20 of the compaction mesh 13 are designed as DFT wires.
[0099] Figures 1 and 2 show that the compaction mesh 13 is woven into the support mesh 12 in such a way that a compacted area 13a with a first porosity 13b and two support areas 12a, each with a second porosity 12b, which are free with respect to the compaction mesh 13, are formed. M / CAN-431-PC
[0100] 17
[0101] It can be seen that the densification network 13 is formed by additional filaments 21 which are only interwoven into that area of the supporting network 12 which, in the implanted state, is intended to reduce blood flow into a lesion.
[0102] By interweaving additional filaments 21 or by interweaving the densification network 13 into only a section of the support body 11, the densified area 13a is formed, which is sufficiently impermeable to blood flow into a lesion. By limiting the additional filaments 21 to a selected area of the support body 11, the amount of metal in the support body 11 can be reduced, thereby decreasing the risk of thrombus formation.
[0103] The two sections of the support body 11, which comprise only the support mesh 12, are free with respect to the compression mesh 13. These sections of the support body 11 form the support areas 12a, which are designed to provide a sufficiently high support force to anchor the implant 10 in the vessel.
[0104] The ratio of the first porosity 13b of the compacted area 13a to the second porosity 12b of the support areas 12a is between 1:1.15 and 1:2, in particular between 1:1.2 and 1:2, in particular between 1:1.4 and 1:2, in particular between 1:1.6 and 1:2, in particular between 1:1.8 and 1:2.
[0105] Such a ratio of the first porosity 13b to the second porosity 12b results in the support areas 12a having a sufficiently high support force to anchor the implant 10 in the vessel, and the denser area 13a being sufficiently blood-tight to reduce blood flow into a lesion. Both functions are fulfilled, with the thrombogenicity of the implant 10 being optimized.
[0106] The first porosity 13b is between 45% and 65%. This means that the first porosity 13b is so low that blood flow in the implanted state can be at least partially diverted from a lesion.
[0107] The second porosity 12b is between 75% and 90%. This second porosity 12b is sufficiently high to maintain blood flow, at least to a large extent, into an outgoing vessel when the device is implanted. M / CAN-431-PC
[0108] 18
[0109] The filaments 20, 21 of the support mesh 12 and the compaction mesh 13 each form meshes. It can be seen that the support areas 12a have a larger mesh size than the compacted area 13a. The first and second porosities 12b, 13b can be varied by the mesh size.
[0110] Figures 1 and 2 show that the compaction mesh 13 is arranged in a central longitudinal section of the support body 11. A proximal and a distal longitudinal section of the support body 11 are unobstructed with respect to the compaction mesh 13.
[0111] The support body 11 according to Figs. 1 and 2 has three regions along its longitudinal axis: a compacted region 13a and two support regions 12a. The compacted region 13a, i.e., the region in which the compaction mesh 13 is interwoven into the support mesh 12, is overlaid on both sides by the support mesh 12.
[0112] The two support areas 12a are separated from each other by the compacted area 13a. The support body 11 has two support areas 12a, which are arranged proximal and distal to the compaction mesh 13 and the compacted area 13a, respectively.
[0113] The compaction mesh 13 is interwoven into the support mesh 12 in such a way that a single-layer wall is formed. The compaction mesh 13 is interwoven into the support mesh 12 in the same plane. The filaments 20, 21 of the support mesh 12 and the compaction mesh 13 are arranged in the same plane.
[0114] It can be seen that the filaments 20 of the support mesh 12 have a larger diameter than the filaments 21 of the compression mesh 13. The filaments 20 of the support mesh 12 have a sufficiently large diameter to provide the necessary support force for the secure anchoring of the implant 10.
[0115] The first porosity 13b of the densified area 13a and the second porosity 12b of the support areas 12a can be adjusted or changed by the diameter of the filaments 20, 21. The ratio between the diameter of the M / CAN-431-PC
[0116] 19
[0117] The ratio of the diameter of the filaments 20 of the support mesh 12 and the diameter of the filaments 21 of the compaction mesh 13 is at most 1:2.
[0118] Figures 1 and 2 show that the support mesh 12 and the compression mesh 13 each form closed loops 16 at their proximal and distal longitudinal ends 14a, 14b, 15a, 15b. The closed loops 16 at one longitudinal end 14a, 15a are formed by redirecting the filaments 20, 21. The closed loops 16 at the other longitudinal end 14b, 15b are formed by welding or crimping open filament ends.
[0119] The number of filaments 20, 21 in the densified area 13a is at least twice as large as the number of filaments 20 in the support mesh 12. The porosity of the densified area 13a and the support areas 12a can be adjusted by the number of filaments 20, 21.
[0120] The filaments 20, 21 of the support mesh 12 and the compression mesh 13 are designed as DFT wires comprising a radiopaque core material sheathed in a superelastic metal, in particular nitinol. Other materials for the filaments 20, 21 are conceivable.
[0121] Figures 1 and 2 show that the filaments 20, 21 have a braiding angle relative to the longitudinal axis of the support body 11.
[0122] According to Fig. 1, the filaments 20, 21 of the support mesh 12 and the compaction mesh 13 have the same braiding angle over the entire length of the support body 11. The first porosity 13b of the compacted area 13a and the second porosity 12b of the support area 12a are determined by the number of filaments 20, 21 and the filament diameter, assuming a constant braiding angle.
[0123] According to Fig. 2, the filaments 20, 21 in the densified area 13a have a larger braiding angle than the filaments 20 in the support area 12a. In addition to the number of filaments 20, 21 and the filament diameter, the first porosity 13b of the densified area 13a and the second porosity 12b of the support area 12a can be adjusted by the braiding angle. M / CAN-431-PC
[0124] 20
[0125] It can be seen that the filaments 20 of the support mesh 12 have a different braiding angle in the support areas 12a than in the densified area 13a. The porosity of the densified area 13a or the first porosity 13b is determined in this case by the number of filaments 20, 21 as well as by the filament diameter and the braiding angle of the filaments 20, 21.
[0126] To produce the support body 11 of the implant 10, the support mesh 12 and the compression mesh 13 are formed essentially simultaneously, or at least in a single operation. The process begins by weaving the filaments 20 of the support mesh 12 together in a tubular fashion on a braiding mandrel, thus forming a support area 12a. Once a portion of the support body 11 has been created, one or more additional filaments 21 are incorporated into the braiding process and interwoven with the filaments 20 of the support mesh 12. In this way, the compression mesh 13 is formed integrally with the support mesh 12.
[0127] The filaments 21 of the compaction mesh 13 are preferably V-shaped in the support mesh 12, wherein the apex of the V-shaped filament 21 forms the edge loops 16 of the compaction mesh 13 or the deflection points of the edge loops 16.
[0128] List of references
[0129] 10 implants
[0130] 11 Support bodies
[0131] 12 supporting mesh
[0132] 12a Support area
[0133] 12b first porosity
[0134] 13 compaction network
[0135] 13a compacted area
[0136] 13b second porosity
[0137] 14a proximal longitudinal end of the support mesh
[0138] 14b distal longitudinal end of the support mesh
[0139] 15a proximal longitudinal end of the compaction network
[0140] 15b distal longitudinal end of the compression mesh M / CAN-431-PC closed loops filaments of the support mesh filaments of the compression mesh
Claims
M / CAN-431-PC 22 Claims 1. Medical implant (10) for treating a local lesion in a vessel, in particular for treating a bifurcation aneurysm, comprising a radially compressible and expandable support body (11) having at least one support mesh (12) and a densification mesh (13), each formed by interwoven filaments (20, 21), wherein the densification mesh (13) is interwoven section by section into the support mesh (12) such that at least one densified area (13a) with a first porosity (13b) and at least one support area (12a) with a second porosity (12b), which is free with respect to the densification mesh (13), is formed, characterized by the fact that the ratio of the first porosity (13b) to the second porosity (12b) is between 1:1.15 and 1:2, in particular between 1:1.2 and 1:2, in particular between 1:1.4 and 1:2, in particular between 1:1.6 and 1:2, in particular between 1:1.8 and 1:
2.
2. Medical implant (10) according to claim 1, characterized by the fact that the first porosity (13b) is between 45% and 65%, in particular at most 60%, in particular at most 55%, in particular at most 50%.
3. Medical implant (10) according to claim 1 or 2, characterized by the fact that the second porosity (12b) is between 75% and 90%, in particular at least 80%, in particular at least 85%.
4. Medical implant (10) according to one of the preceding claims, characterized by the fact that the filaments (20, 21) of the support mesh (12) and the compression mesh (13) each form meshes, wherein the at least one support area (12a) has a larger mesh size than the at least one compression area (13a). M / CAN-431-PC 23 5. Medical implant (10) according to one of the preceding claims, characterized by the fact that the compression mesh (13) is arranged in a central longitudinal section of the support body (11) such that a proximal and / or a distal longitudinal section of the support body (11) is free with respect to the compression mesh (13).
6. Medical implant (10) according to one of the preceding claims, characterized by the fact that the compression mesh (13) is woven into the support mesh (12) in such a way that a single-layer wall is formed.
7. Medical implant (10) according to one of the preceding claims, characterized by the fact that the filaments (20) of the support mesh (12) have a larger diameter than the filaments (21) of the compression mesh (13).
8. Medical implant (10) according to one of the preceding claims, characterized by the fact that the ratio between the diameter of the filaments (20) of the compression mesh (13) and the diameter of the filaments (21) of the support mesh (12) is at most 1:2, in particular at most 1:2, in particular at most 1:2.5, in particular at most 1:2.75, in particular at most 1:3, in particular at most 1:
4.
9. Medical implant (10) according to one of the preceding claims, characterized by the fact that the number of filaments (20, 21) in the at least one compacted area (13a) is at least twice, in particular at least three times, in particular at least four times, in particular at least five times, greater than the number of filaments (20) in the at least one support area (12a).
10. Medical implant (10) according to one of the preceding claims, characterized by the fact that the support mesh (12) and the compression mesh (13) are each attached to the M / CAN-431-PC 24 closed loops (16) are formed at the proximal and distal longitudinal ends (14a, 14b, 15a, 15b).
11. Medical implant (10) according to one of the preceding claims, characterized in that the filaments (20, 21) of the support mesh (12) and / or the compression mesh (13) comprise stainless steel or a superelastic metal, in particular nitinol, and / or a plastic material, in particular bioresorbable, and / or radiopaque material, in particular platinum.
12. Medical implant (10) according to one of the preceding claims, characterized by the fact that at least one marker element is arranged at the transition between the at least one compacted area (13a) and the at least one support area (12a).
13. Medical implant (10) according to one of the preceding claims, characterized by the fact that the filaments (20, 21) have a braiding angle with respect to the longitudinal axis of the support body (11), wherein the filaments in the at least one compacted area (13a) have a different, in particular larger, braiding angle than the filaments in the at least one support area (12a).
14. Medical implant (10) according to one of the preceding claims, characterized by the fact that the at least one compacted area (13a) has a different, in particular larger, cross-sectional diameter than the at least one support area (12a).
15. Medical implant (10) according to one of the preceding claims, characterized by the fact that the support body (11) has an antithrombogenic coating, which in particular comprises heparin and / or fibrin. M / CAN-431-PC 25 16. Method for manufacturing a medical implant (10) according to one of the preceding claims, in which at least two filaments (20) are helically braided around a common longitudinal axis and form a supporting braid (12), wherein during braiding the Filaments (20) of the support network (12) one or more filaments (21) forming a densification network (13) are integrally woven into at least one section of the support network (12) such that at least one densified area (13a) with a first porosity (13b) and at least one support area (12a) with a second porosity (12b) which is free with respect to the densification network (13) is formed.