Medical device for treating blood vessel diseases, in particular an endovascular implant, and production method

Abstract

The invention relates to a medical device for treating hollow organs of the body, in particular an endovascular implant, comprising a tubular support structure (10) which has a wall with a substantially uniform wall thickness t and which is convertible from a radially compressed state to a radially expanded state. The invention is characterized in that the support structure (10) is adapted to plastically deform, during the transition from the compressed state to the expanded state, such that the wall thickness t of the wall decreases, in particular uniformly.

Description

[0001] Medical device for the treatment of blood vessel diseases, in particular endovascular implant, and manufacturing process

[0002] The invention relates to a medical device for the treatment of blood vessel diseases, in particular an endovascular implant, with the features of the preamble of claim 1. The invention further relates to a manufacturing method for such a device.

[0003] A device similar to the type mentioned above is known, for example, from US 2022 / 0226133 A1. This patent describes a stent that has a substantially tubular support structure. The tubular support structure is formed from a grid-like arrangement of webs arranged in a plane of the tubular support structure. This plane of the support structure essentially corresponds to a cylindrical surface. The webs together form a wall as part of the support structure, with a wall thickness that is essentially uniform. This results from the manufacturing process of the known stent, in which a tubular blank is first provided, and the structure of the support framework, or the webs, is then added by laser cutting. This creates openings bounded by the webs, resulting in a grid-like support structure.The wall thickness of the original, tubular blank is retained, so that the known stent essentially has a uniform wall thickness.

[0004] The supporting structure, formed from webs, comprises in particular webs that are arranged in a serpentine pattern. Two webs arranged at angles to each other are monolithically connected via a connecting arch, a so-called apex.

[0005] The well-known stent is used to be inserted into a blood vessel via a balloon catheter. The support structure is therefore manufactured in a state where it has a cross-sectional diameter that is at least nearly reached during implantation in the blood vessel; such a state is referred to as the expanded state.

[0006] 102355-WO - MSP Keller Schneider

[0007] September 16, 2025 Patent and Trademark Attorneys To insert the stent into the blood vessel, the support structure must be radially compressed, causing adjacent struts to fold against each other.

[0008] When the stent is compressed onto the balloon of the balloon catheter, the ribs and especially the tips deform plastically to reduce the angle between them. This can be achieved using a crimping device that exerts a radial force on the stent, overcoming the bending resistance of the tips and causing the stent to clamp onto the balloon. The stent, along with the catheter, is then guided to the treatment site in the blood vessel. There, the balloon is filled with fluid, causing the stent to expand radially. The pressure within the balloon provides the energy to plastically deform the ribs and tip again. This increases the angle between the ribs, pressing the stent against the vessel wall. Due to this plastic deformation, the stent resists the radial inward force of the vessel and thus supports the vessel wall.The ribs and tips therefore provide bending resistance against deformation and thus against radial compression of the stent by the inward force of the vessel.

[0009] Generally, each individual rib has a rib width, which is essentially determined in the circumferential plane of the wall. Furthermore, each rib has a depth or thickness that essentially corresponds to the wall thickness. If each rib is considered as a bending beam, then the rib width, in particular, has a significantly greater influence on the rib's bending resistance, or rather its tip, than the rib thickness. The force with which the stent resists radial compression by the vessel is therefore largely determined by the rib width. Consequently, it would be possible to reduce the wall thickness of the support structure, and thus the rib thickness, to a minimum.At the same time, however, an excessive reduction in wall thickness leads to the webs deforming due to torsion during the expansion of the support structure, i.e., during the transition from the radially compressed state to the radially expanded state, which can lead to an uneven and undesirable geometric arrangement of the webs relative to each other in the expanded state.

[0010] 102355-WO - MSP Keller Schneider

[0011] September 16, 2025 Patent and Trademark Attorneys Against this background, it has proven effective in practice to choose the bridge thickness so that it at least corresponds to the bridge width, and often is even greater. However, this also entails disadvantages.

[0012] On the one hand, increased stent thickness, and thus increased wall thickness of the support structure, leads to greater disruption of blood flow within a blood vessel. Flow turbulence occurs as blood passes through the stent, which can cause eddies immediately behind the stent, leading to stagnation. This creates a breeding ground for thrombi, which can form there and further impair blood flow. Another disadvantage is that the increased wall thickness of the support structure also results in a larger cross-sectional diameter for the entire balloon catheter and stent assembly, limiting the maneuverability of the system through the blood vessels. This also increases the risk of injuring the blood vessel during the delivery of such a stent using a balloon catheter.

[0013] These disadvantages are exacerbated in stents made of polymers rather than metals. US 2022 / 0226133 A1 describes such a polymer stent. Compared to metals, polymers have a lower modulus of elasticity, meaning that sufficient resistance to compression by the vessel via the bending resistance of the stent structure, particularly the webs and tips, can only be achieved by increasing the size of the webs. Consequently, the web thicknesses, i.e., the wall thicknesses of the supporting structures, of polymer stents are typically greater than those of metal stents. This increases the risk of blood turbulence and corresponding flow stagnation, which in turn leads to an increased risk of thrombus formation. Furthermore, polymer stents are particularly difficult to guide to the treatment site using catheters, as the overall diameter of the catheter-stent system is increased.

[0014] Against the background of this prior art, the invention aims to provide a medical device for the treatment of body hollow organs, in particular an endovascular implant, which is dimensionally stable in a body hollow organ.

[0015] 102355-WO - MSP Keller Schneider

[0016] September 16, 2025 Patent and trademark attorneys can position the device and at the same time hardly impairs the function of the body's hollow organ, in particular reducing the risk of thrombus formation as an endovascular implant. Furthermore, it is an object of the invention to specify a manufacturing process for such a medical device.

[0017] According to the invention, this problem is solved with regard to the medical device by the subject matter of claim 1 and with regard to the manufacturing process by the subject matter of claim 13.

[0018] The invention is based specifically on the concept of providing a medical device for treating hollow body organs, in particular a stent, with a tubular support structure having a wall of substantially uniform thickness. The support structure is also capable of transitioning from a radially compressed state to a radially expanded state. According to the invention, the support structure adapts to plastically deform during the transition from the compressed state to the expanded state, thereby reducing the wall thickness, particularly uniformly.

[0019] Where blood vessels are mentioned below, this applies analogously to all conceivable hollow body organs, i.e., hollow organs in a human or animal body. Such a hollow organ may, for example, be located in the lungs, particularly in the bronchi, or may include the esophagus, as well as visceral or urogenital organs. It is also possible to use the device according to the invention in the area of ​​heart valves. In general, the device is also suitable for treating defects of the heart, particularly in the area of ​​the heart valves. Defects in blood vessels near the heart, such as the aorta, can also be treated with the device. Where a vessel wall is mentioned below, this refers not only to the wall of a blood vessel but also to the wall of any other hollow organ.

[0020] While in previously known medical devices radial expansion is achieved by the deformation of the connecting tips of the support structure, thus allowing the struts to move away from each other, the

[0021] 102355-WO - MSP Keller Schneider

[0022] September 16, 2025. Patent and trademark attorneys. The medical device according to the invention involves a plastic deformation of the support structure material. The underlying idea is that the entire support structure stretches during the transition from the compressed state to the expanded state, i.e., during expansion, so that the wall thickness is reduced simultaneously across the entire support structure. This results in plastic stretching of the support structure material, which in turn reduces the wall thickness of the support structure. In the expanded state, which can essentially correspond to the implanted state of the medical device, the support structure thus has a wall with a comparatively small thickness, so that flow turbulence that promotes thrombus formation is hardly possible. The risk of thrombus formation is thus efficiently reduced.

[0023] In other words, according to the invention, the support structure is configured such that an increase in the circumference of the support structure is accompanied by a reduction in the wall thickness. Essentially, the support structure is thus stretched circumferentially at the material level. This radial expansion can simultaneously result in an axial shortening of the support structure. Such behavior can be taken into account in advance during the design of the medical device.

[0024] The supporting structure can therefore be manufactured in a compressed state and subsequently expanded within a body cavity organ, whereby the supporting structure retains its expanded state.

[0025] It is particularly advantageous if the support structure comprises or is formed from at least one polymer material. The polymer material can be synthetic or biological. It is also possible for the polymer material to be biodegradable, meaning it dissolves in the implanted state over a predetermined period. This can be advantageous for temporarily supporting a blood vessel until healing occurs, enabling the blood vessel to spontaneously resume its original support function. A medicinal agent can be embedded in the polymer material, particularly in the biodegradable polymer material. Examples of possible agents will be explained in more detail later.

[0026] 102355-WO - MSP Keller Schneider

[0027] September 16, 2025 Patent and Trademark Attorneys It has been shown that it is advantageous if the polymer material includes polycaprolactones (PCL), polylactides (PLA, PLLA), polyurethanes and / or hydrogels.

[0028] Therefore, for the purposes of this application, hydrogels, preferably polyvinyl alcohols (PVA), gelatin, collagen and / or elastin, are considered to be polymers.

[0029] In general, various polymer materials can be used. In particular, several different polymer materials can be combined with one another. Therefore, mixtures of different polymer materials can be used. Within the scope of this disclosure, the term "polymer material" consequently refers not only to a single polymer but also describes mixtures of several polymers. It is also possible to construct the implant in several layers, with the layers being formed from different polymer materials. Thus, both material combinations and mixtures, as well as composite materials, can be used as implant materials. It is particularly advantageous if the implant material includes a radiopaque material and / or medical agents. It is also possible for the polymer materials of the layers to be identical.

[0030] The polymer material can be a synthetic or biological polymer. Examples of such polymers include polycaprolactones (PCL), polylactides (PLA, PLLA), polyurethanes, or a combination of at least two synthetic or at least two biological polymers. A combination of a synthetic and a biological polymer is also possible. In the context of this application, proteins are considered biological polymers. In addition to plastic properties, the polymer material can also exhibit partially elastic properties. In particular, the polymer material can comprise at least one thermoplastic material, such as polyurethane.

[0031] It is also possible for the support structure to include at least one metal component. The metal can serve to reinforce the polymer or to provide X-ray visibility. It is preferred if the metal is also plastically deformable. Alternatively, the support structure can consist solely of metal.

[0032] 102355-WO - MSP Keller Schneider

[0033] September 16, 2025 Patent and trademark attorneys. Metals exist. This can involve a single plastically deformable metal or several plastically deformable metals. One possible deformable metal is tantalum.

[0034] The support structure can be balloon-expandable. It is preferred that the support structure be in a compressed or at least partially compressed state after manufacturing. When the support structure is subsequently compressed onto a balloon of a balloon catheter, the wall thickness may increase minimally. It is also possible that the support structure has a smaller diameter than the balloon in its manufactured state. When applied to the balloon, the support structure is pre-expanded outwards. It is advantageous if the wall has a uniform thickness in a manufactured state, particularly in the radially compressed state of the support structure. Naturally, manufacturing tolerances may result in variations in wall thickness.However, these tolerance deviations in wall thickness are preferably no more than 7%, in particular no more than 5%, and in particular no more than 3% across the entire support structure.

[0035] In a preferred embodiment of the medical device, the ratio between the wall thickness of the support structure in its radially expanded state and its wall thickness in its radially compressed state is at most 50%, particularly at most 30%, particularly at most 20%, and particularly at most 10%. In other words, the wall thickness of the support structure in its expanded state can be one-tenth of the wall thickness of the support structure in its radially compressed state. Since the resistance of the support structure to the inward force of the hollow body organ is primarily exerted across the entire wall and not through the mechanical bending properties of individual structural elements, the support structure can be designed to exert sufficient resistance against the blood vessel even in its expanded state to support the blood vessel.

[0036] In general, it should be noted that the percentage change in wall thickness mentioned here is directly proportional to the change in the cross-sectional diameter of the

[0037] 102355-WO - MSP Keller Schneider

[0038] September 16, 2025 Patent and Trademark Attorneys. The cross-sectional diameter of the support structure, when implanted within a body cavity, depends on the geometry of that cavity. The diameter of the body cavity, particularly the diameter of a blood vessel, may vary, resulting in varying wall thickness along the implant when expanded. Furthermore, the implant wall may be stretched more on the outer surface of a curved vessel than on the inner surface, leading to a thinner wall thickness on the outer surface than on the inner surface.

[0039] Within the scope of this application, the expansion diameter is therefore defined as a recommended diameter after expansion (nominal diameter). At the recommended diameter, the support structure typically exhibits a support function characterized by sufficient resistance to the inward force of the body's hollow organ while simultaneously providing high stability.

[0040] The medical device according to the invention can be designed as a type of plaster in which a large part of the wall is formed by material. In previously known metallic stents and also most polymer stents, a large part of the wall in the expanded state is formed by openings between structural elements of the support structure. The invention can deviate from this and provide an increased proportion of material-covered wall surface, since the amount of material is less crucial for the expandability of the support structure. As a type of plaster, the medical device can have a mechanical function for stabilizing the vessel wall, but can also additionally, predominantly, or exclusively have a fluid-dynamic or protective function. Protective functions include, for example, the release of medication into the vessel wall.

[0041] In a particularly preferred embodiment of the medical device, the wall has a wall thickness of at most 30 pm, particularly at most 4 mm, when the cross-sectional diameter of the support structure in the radially expanded state is between 3 mm and 6 mm, in particular between 3.5 mm and 5 mm, preferably 4 mm.

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[0043] September 16, 2025 Patent and Trademark Attorneys 20 m, in particular at most 10 pm, in particular at most 5 pm. Such a small wall thickness ensures very good flow through the support structure in the implanted state, largely preventing the formation of flow turbulence. Such a thin wall thickness is particularly advantageous when the medical device has a predominantly fluid-dynamic or protective function. For medical devices that mainly perform a mechanical function, the wall thickness in the expanded state is advantageously at most 80 pm, in particular at most 50 pm, in particular at most 20 pm.

[0044] The support structure, in particular the wall, can have patterned openings, wherein the openings in a manufacturing state, particularly in the radially compressed state, of the support structure are circular, slit-shaped, or polygonal, particularly rhomboid. A slit-shaped opening can also essentially have an oval base shape. In principle, it is conceivable that the support structure can be designed as a completely closed entity, i.e., as a closed tube. Since the expansion occurs via material-inherent properties, namely an elongation of the material of the support structure, which reduces the wall thickness during expansion, it is not necessary to provide individual, interconnected structural elements that enable expansion. This is a significant difference from the prior art.

[0045] With regard to treatment goals, however, it is advisable to provide openings in the vessel wall, for example, to ensure continued nutrient supply to the blood vessel wall. The medical device can also be used to bridge aneurysms, and it is medically advantageous to maintain blood flow into the aneurysm. This flow should be reduced to avoid further stressing the blood vessel wall in the area of ​​the aneurysm. At the same time, it is beneficial to supply the blood vessel wall within the aneurysm with nutrients or to promote targeted thrombus formation within the aneurysm to close it. In this respect, the

[0046] 102355-WO - MSP Keller Schneider

[0047] September 16, 2025 Patent and Trademark Attorneys The support structure has corresponding openings, which may have different shapes. If the openings are circular in the manufacturing state, expansion results in a deformation of the openings, so that after expansion essentially oval or elongated hole-like openings are present, the main axis of which extends in the circumferential direction of the support structure.

[0048] If slot-shaped openings are provided in the support structure, these can run parallel to a longitudinal axis of the support structure, along a circumferential direction of the support structure, and / or obliquely to both the longitudinal axis and the circumferential direction. Naturally, it is possible for several different slot-shaped openings to be provided. The support structure can therefore have slot-shaped openings that run parallel to the longitudinal axis or the circumferential direction, as well as slot-shaped openings that run obliquely to both the longitudinal axis and the circumferential direction. In this respect, all geometric combinations of opening arrangements are conceivable. For example, circular openings can also be combined with slot-shaped or oval openings and / or polygonal openings.During radial expansion of the support structure, slot-shaped openings extending parallel to a longitudinal axis of the support structure can deform into cloverleaf-like or rhomboid-shaped openings. Slot-shaped openings extending circumferentially or obliquely along the wall of the support structure can stretch along a longitudinal direction of the support structure during expansion, thus assuming a rhomboid or cloverleaf-like geometry. Depending on the geometry of the openings, the deformation resulting from the expansion can lead to an increase or, alternatively, a decrease in the size of the opening area. It is also possible that the opening area remains essentially unchanged or nearly unchanged.

[0049] In a further preferred embodiment of the invention, the minimum distance between two openings in the wall of the support structure in its radially expanded state is greater than the wall thickness in the radially expanded state of the lattice structure. This ensures particularly good stability of the support structure in its expanded state.

[0050] 102355-WO - MSP Keller Schneider

[0051] September 16, 2025 Patent and Trademark Attorneys Particular advantages are evident when the ratio between the wall thickness and the minimum spacing in the expanded state of the support structure is less than 80%, in particular less than 60%, in particular less than 40%, and in particular less than 20%. In other words, the minimum spacing between two openings in the wall of the support structure in its expanded state can be five times the wall thickness in the expanded state of the support structure.

[0052] Furthermore, in preferred embodiments, the ratio between the open area of ​​the wall and the total area (open area and closed area) of the wall, in particular the wall porosity, is less than 50%. The ratio between the open area of ​​the wall and the total area of ​​the wall is referred to as porosity. This is usually specified in the expanded state of the support structure. In the medical device described here, the manufacturing state corresponds to the radially compressed state. At the same time, the porosity of the medical device according to the invention applies in all states, especially also in the expanded state, since the material of the support structure preferably expands uniformly during expansion.In general, the porosity, particularly in the expanded state of the support structure, can be less than 80%, more specifically less than 70%, more specifically less than 60%, preferably less than 50%, more specifically less than 40%, more specifically less than 30%, and more specifically less than 20%. Such a particularly low porosity, combined with the larger distance between the openings in the wall of the support structure, ensures a secure fit of the support structure to the vessel wall and thus a homogeneous distribution of forces on the vessel wall. Forces exerted locally by the support structure on the vessel wall, and the associated risk of vascular injury or inflammatory reactions, are therefore reduced. This is a particular advantage of the medical device described here compared to the prior art.

[0053] In principle, porosity can increase during expansion. It is also conceivable that the porosity remains essentially unchanged or even decreases. This depends on...

[0054] 102355-WO - MSP Keller Schneider

[0055] September 16, 2025. Patent and trademark attorneys commented on the geometry of the openings described above. Because the material stretches during expansion and the wall becomes thinner, an increase in porosity does not necessarily occur during expansion. This represents a further difference from the prior art.

[0056] Furthermore, the support structure can be designed to have at least two material layers with different properties. Generally, the support structure can be made of several different polymers. Advantageously, polymers with different properties for medical treatment are combined. In particular, the material layers can be biodegradable, exhibiting different degradation rates. For example, a first material layer can be biodegradable for a longer period than a second material layer. Specifically, a first material layer can be designed to degrade faster than a second material layer.

[0057] With regard to the materials used, further medically advantageous configurations are conceivable. For example, a medicinal agent can be embedded in the polymer material, particularly in one of at least two material layers. If the support structure consists of several material layers, the medicinal agent is preferably embedded in an outer layer of the support structure. In this respect, the medical device can exhibit pharmaceutical properties. For example, cytostatic agents can be integrated, which inhibit the proliferation of biological cells and thus, for instance, reduce the risk of stenosis or restenosis in the blood vessel. It is also possible to use medicinal agents with anti-inflammatory and / or antithrombotic effects.Such active substances can serve to reduce arteriosclerotic processes.

[0058] It is also conceivable to embed medical agents in the polymer material that promote cell function and cell proliferation of endothelial cells in order to accelerate recovery.

[0059] 102355-WO - MSP Keller Schneider

[0060] September 16, 2025 Patent and Trademark Attorneys to achieve endothelialization and thus promote the adhesion of the support structure to a vessel wall. Such active substances can be, for example, growth factors. Other medical agents that can be embedded in the polymer material can have adhesion-promoting properties to accelerate the attachment of endothelial cells to the support structure. Through adhesion-promoting substances, the support structure can essentially be "glued" to the vessel wall. The adhesive forces thus connect the support structure to the vessel wall across its entire surface and stabilize the support structure, particularly with regard to the shear stresses of the pulsating blood flow. This is especially advantageous when the support structure has a very thin wall in its expanded or implanted state.

[0061] If the wall of the support structure has at least two layers of different polymer materials, it can be particularly advantageous if the polymer material containing the medicinal agents is located on either the outer or inner surface of the wall. This allows for targeted delivery of the medicinal agents either to the blood vessel wall or to the blood flowing through it. If the medicinal agents are embedded in a layer of material on the outer surface of the wall, they can effectively diffuse into a vessel wall supported by the device, particularly the support structure. It is especially advantageous if both layers of material contain different active agents, which can selectively act on the blood flowing through them and / or on the vessel wall, either individually or separately.Furthermore, one or more additional material layers may be provided, located between a radially inner and a radially outer material layer, and may themselves contain active ingredients or be free of active ingredients.

[0062] In this context, it is advantageous if the polymer material containing the medical agents is biodegradable. This allows for a targeted and long-term release of the active ingredients into the surrounding tissue or bloodstream.

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[0064] September 16, 2025 Patent and Trademark Attorneys In general, when embedding pharmaceutical agents in a polymer material, it is particularly advantageous if the polymer material, especially if it forms the inner surface of the support structure, is biodegradable. The degradation of the polymer material, i.e., its breakdown, efficiently releases the pharmaceutical agents. The release rate can be determined in vitro by immersing a prototype of the device in an electrolyte solution, preferably under flow conditions similar to human blood. The release rate of the support structure can then be precisely configured by adjusting the layer thickness or material composition.

[0065] If the support structure consists of several biodegradable layers, it can be advantageous for the individual layers to dissolve at different rates. For example, the individual layers can dissolve radially from the inside out. This gradually reduces the cross-sectional profile of the support structure and thus the disruption of blood flow, while the outer layer remains firmly attached to the vessel wall. Alternatively, the outer layer can dissolve gradually as the first layer, followed by other, more internal layers. This allows drugs dissolved in the outer layer to diffuse into the vessel wall in an initial phase after implantation of the device.

[0066] It is also conceivable that the polymer material itself is porous. For example, the polymer material forming the support structure could be a foam-like material. This increases the porosity of the support structure at the micro level and can promote the adhesion of endothelial cells and thus the integration of the support structure into biological tissue. This can efficiently support tissue healing.

[0067] A similarly high level of microporosity can be achieved by using a polymer material produced by electrospinning. Such a polymer material is formed from a multitude of microscopically small threads that are arranged in a largely random orientation, thus forming a felt-like fabric or network.

[0068] 102355-WO - MSP Keller Schneider

[0069] September 16, 2025. Patent and trademark attorneys. However, it is fundamentally possible to produce fabrics or nets with regularly aligned threads using electrospinning. In particular, the support structure can consist of a network of aligned, preferably counter-oriented, helical threads forming diamond-shaped openings. During expansion, the threads can stretch. This is accompanied by a reduction in thread thickness, at least in certain sections. This applies especially to the threads that extend at least partially in the circumferential direction of the support structure.

[0070] Furthermore, high microporosity can also be achieved using a foam-like polymer. However, microporosity must be distinguished from the porosity of the support structure described above, particularly the surface area of ​​the support structure. The surface area of ​​the support structure has larger openings than the microporosity. Therefore, the openings that constitute the porosity described above are larger than the pores that constitute the microporosity. Microporosity and the porosity achieved through these openings can be combined.

[0071] For example, the openings can have an area on the order of 0.01 mm². 2 and 4 mm 2 Pores can have dimensions between 1 pm, for example. 2 and 100 pm 2They exhibit various characteristics. Another difference can be that openings have a regular geometry and distribution, whereas pores have a variable geometry. Openings can also extend across the entire wall, whereas individual pores are only distributed across a portion of the wall.

[0072] In a multi-layered support structure, it is also possible that only one or only some of the material layers are porous. For example, it can be advantageous if only a radially outer material layer is porous, perhaps to release active ingredients more effectively, while a radially inner material layer is smooth and thus exhibits better resistance to blood flow.

[0073] In the present invention, the support structure is preferably expandable. This, according to the invention, causes the radial expansion of the support structure. The expansion is

[0074] 102355-WO - MSP Keller Schneider

[0075] September 16, 2025 Patent and trademark attorneys preferably actively trigger this process, in particular by inflating a balloon on which the medical device, especially the support structure, is mounted in a compressed state. The balloon can be inflated, for example, with a saline solution, especially with the addition of a contrast agent, whereby a fluid pressure of no more than 12 bar is set within the balloon. As the fluid pressure builds up, the balloon expands radially, thereby also expanding the medical device, especially the support structure. Due to the plastic deformation of the support structure's wall, the support structure retains its expanded state when the balloon is subsequently compressed again to be removed from the blood vessel. The medical device with the expanded support structure then remains in the blood vessel, preferably lying tightly and supportively against the blood vessel wall.It is possible that the supporting structure, after expansion, may be slightly compressed again by elastic forces or allowed to be compressed by the vessel wall, a process known as "recoiling." The main thing is that the supporting structure and the vessel wall remain in contact so that forces can be transmitted.

[0076] Due to the material's inherent elastic properties, the medical device according to the invention has the additional advantage of being able to adapt well to different geometries of blood vessels. Blood vessels are not generally straight and tubular, but have various shapes and curvatures. The medical device described here can adapt particularly well to such conditions and therefore provide good support with minimal impact on blood flow.

[0077] To ensure that the support structure conforms well to an irregular, especially curved, vessel geometry in its implanted state, it is advantageous for the balloon of the balloon catheter to be "compliant." Such balloons can be expanded with a pressure of less than 1 bar. In its compressed state, the balloon is tubular. When inflated, the balloon follows the contour of the vessel and presses the implant against the vessel wall without significantly altering the vessel's anatomy. The implant remains in this configuration and continues to follow the contour even after the balloon deflates.

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[0079] September 16, 2025. Patent and trademark attorneys of the vessel. The implant can thus assume a curved contour or a contour with varying diameter along the vessel. Accordingly, the elongation of the wall, and therefore the wall thickness, can vary along the implant and around its circumference in the expanded state. This configuration is particularly suitable for support structures with fluid-dynamic or protective functions. For example, if a calcified vessel is to be dilated, the use of a "non-compliant or semi-compliant" balloon is advisable. Such balloons are folded in the compressed state and can be pressurized to an internal pressure of up to 12 bar. These balloons can be used particularly in support structures that have a mechanical function.Regardless of the balloon type, it is advantageous if the implant, when expanded, also allows for deformation within its elastic range, so that it follows the pulsation of the vessel. This is achieved through the appropriate selection of the implant material.

[0080] It is preferred that the balloon expands uniformly along its length. It is also advantageous if the balloon has a rough or sticky outer surface for contact with the support structure. Both of these measures prevent the support structure from sliding or slipping on the balloon as it expands, or from being axially compressed between two expanded balloon ends (hourglass effect).

[0081] Regardless of the implantation site, it is advantageous in the present invention that the wall thickness of the support structure is largely uniform in its expanded state. Deviations from a uniform wall thickness preferably range from a maximum of 10%, more particularly a maximum of 8%, more particularly a maximum of 6%, more particularly a maximum of 5%, more particularly a maximum of 4%, more particularly a maximum of 3%, and more particularly a maximum of 2%. The uniform wall thickness described herein is preferably maintained in both the longitudinal and circumferential directions of the support structure. Particularly in the circumferential direction, good homogeneity is advantageous to prevent the support structure from overstretching and tearing.

[0082] 102355-WO - MSP Keller Schneider

[0083] September 16, 2025 Patent and Trademark Attorneys The uniform wall thickness described here can be maintained only in the circumferential direction, while variations in the longitudinal direction are possible or even desirable. In the longitudinal direction, the supporting structure can, for example, have a continuously changing wall thickness or areas with varying wall thicknesses. Additionally or alternatively, areas with varying wall thicknesses can be present in the circumferential direction. Areas with a differing, particularly comparatively greater, wall thickness, both in the longitudinal and circumferential directions, are advantageously evenly distributed and stabilize the supporting structure. The comparatively greater wall thickness can be formed as an outwardly directed thickening.

[0084] With regard to ensuring good integration of the medical device into the biological tissue at the treatment site, it can be advantageous if the support structure on the material surface, particularly at least on an outer circumferential surface, has a predetermined surface roughness or a predetermined microstructure. In the context of this application, surface roughness refers to a micro-level unevenness of the surface that does not exhibit a regular pattern. Microstructuring, on the other hand, exhibits such a patterned arrangement. The height or depth of the irregularities can be between 200 nm and 2 pm for both surface roughness and microstructuring. It is advantageous if the surface roughness or microstructuring has a height of 400 nm to 1 pm.It has been shown that such surface roughness or microstructuring results in particularly strong adhesion of biological cells to the surface of the supporting structure.

[0085] Additionally or alternatively, the outer surface of the support structure can also be coated with a chemical or biochemical coating. Such a coating can be tailored to improve the attachment of endothelial cells to the support structure. In general, a surface modification can be provided that improves the healing of the blood vessel being treated and the integration of the medical device into the blood vessel.

[0086] 102355-WO - MSP Keller Schneider

[0087] September 16, 2025 Patent and Trademark Attorneys Through microstructuring and / or coating, the medical device behaves like a type of endovascular plaster that adheres to the inner wall of a blood vessel. This significantly increases the stability of the medical device within the blood vessel. Due to its plaster-like behavior, the medical device can perform a fluid-dynamic function in addition to, or as an alternative to, the mechanical function of the supporting structure. This can, for example, involve redirecting or diverting blood flow, particularly from an aneurysm, a process also known as "flow diversion." It is also possible for the medical device to completely stop bleeding in a plaster-like manner. Furthermore, the medical device can perform a protective function, in particular by acting as a filter or releasing active substances into the vessel wall or the bloodstream.Thus, the medical device can be described as an endovascular patch, which can be described using English technical terms such as "endovascular / intima(l) plaster" or "endovascular / intima(l) patch" or "endovascular / intima(l) skin".

[0088] A subordinate aspect relates to a method for manufacturing a previously described medical device, wherein the method comprises the following steps: a) providing a negative mold having at least one depression on an inner circumference forming a negative structure of a support structure, b) rotating the negative mold about a central axis of rotation, c) introducing a polymer material into the rotating negative mold such that the polymer material is deposited into the depression under the influence of a centrifugal force, d) curing the polymer material while rotating the negative mold to form the support structure, and e) removing the support structure from the negative mold.

[0089] 102355-WO - MSP Keller Schneider

[0090] September 16, 2025 Patent and Trademark Attorneys It may be provided that in step c) the polymer material is introduced into the negative mold by means of an injection needle, the injection needle being positioned coaxially in the negative mold. The introduction of the polymer material can take place with the injection needle fixed in position within the negative mold. Alternatively, the injection needle can be guided longitudinally through the negative mold in a continuous longitudinal motion while the polymer material is being introduced. The injection needle can also be fixed in position at various locations within the negative mold during the introduction of the polymer material.

[0091] The provision of the negative mold according to step a) may comprise the following steps: i. generating a rotationally symmetric mandrel which has at least one protrusion on an outer surface forming a positive structure of the support structure, ii. positioning the mandrel in a mold, wherein the mandrel is aligned coaxially to the mold and an annular space remains between the mandrel and an inner circumferential wall of the mold, iii. filling the annular space with a molding material to form the negative shape of the support structure, and iv. removing the mandrel from the mold.

[0092] The manufacturing process proposed here involves producing the medical device, preferably an implant or stent, by centrifuging the polymer material. The polymer material is introduced into a rotating negative mold, where centrifugal forces ensure that the polymer material is evenly deposited within the mold. This results in a support structure with a particularly uniform wall thickness. A particular advantage of the manufacturing process described here is that centrifugation allows for the production of support structures with not only a very uniform but also a very thin wall thickness. These advantages are especially evident when compared to the

[0093] 102355-WO - MSP Keller Schneider

[0094] September 16, 2025 Patent and Trademark Attorneys present a state of the art in which polymer stents are manufactured by laser cutting. Laser cutting involves high temperatures acting on the polymer material, which limits the material selection and simultaneously requires particularly precise control of the process parameters to prevent unwanted melting of the polymer material. The method described here is particularly well suited for the production of support structures made of multiple material layers.

[0095] The method described here does not preclude its use in initially producing a tubular support structure wall without integrated openings by centrifugation, with openings being introduced into the wall only in a subsequent process step. These openings can, for example, be cut from the wall using a laser.

[0096] Another suitable method for manufacturing the medical device described above is electrospinning, in particular near-field electrospinning (NFES). In NFES, threads are applied in a defined orientation to a cylindrical, electrically conductive collector under the influence of an electrical voltage.

[0097] Specifically, the present invention also discloses a method for manufacturing a previously described medical device, wherein the method comprises the following steps: a) providing a cylindrical, electrically conductive collector and a deposition nozzle; b) applying a voltage between the electrically conductive collector and the deposition nozzle; c) expelling a polymer material from the nozzle so that a polymer thread forms between the collector and the deposition nozzle; and d) depositing the polymer thread, in particular in a helical form, around the cylindrical, electrically conductive collector.

[0098] 102355-WO - MSP Keller Schneider

[0099] September 16, 2025 Patent and Trademark Attorneys The threads can advantageously be oriented helically, with diamond-shaped openings being created by applying threads in a counter-rotating, helical pattern. These openings can form the porosity or microporosity described above. During radial expansion, the diamonds are pulled in a circumferential direction, which changes the angle between the threads. The threads themselves are pulled axially during radial expansion, i.e., along their own axis, which leads to a reduction in their thickness. This, in turn, leads to a reduction in the wall thickness of the support structure, which consists of several overlapping threads. The reduction in wall thickness and thread diameter during expansion is almost proportional. For example, a thread in its resting state can have a diameter between 10 and 80 pm, preferably between 20 and 50 pm.

[0100] The invention is explained in more detail below with reference to an exemplary embodiment and the accompanying schematic drawings. These show

[0101] Fig. 1a shows a side view of a section of a prior art stent with several serpentine-like arranged webs;

[0102] Fig. 1b shows a perspective view of a web of the stent according to Fig. 1a with a web width and a web thickness or wall thickness;

[0103] Fig. 1c shows a perspective view of the bridge according to Fig. 1b, showing the forces acting during compression;

[0104] Fig. 2a shows a side view of a support structure of a medical device according to the invention in a preferred embodiment in the compressed state;

[0105] Fig. 2b shows the support structure according to Fig. 2a in an expanded state;

[0106] Fig. 3a shows a longitudinal section view of the wall of the support structure according to Fig. 2a in the compressed state;

[0107] 102355-WO - MSP Keller Schneider

[0108] September 16, 2025 Patent and Trademark Attorneys Fig. 3b a longitudinal section view of the wall of the support structure according to Fig. 2b in the expanded state;

[0109] Fig. 4a shows a longitudinal sectional view of a balloon catheter with the support structure of a medical device according to the invention in the compressed state according to a preferred embodiment;

[0110] Fig. 4b shows a longitudinal sectional view of the catheter according to Fig. 4a, with the support structure in an expanded state;

[0111] Fig. 5a shows a longitudinal section view through a blood vessel with an aneurysm, with the catheter according to Fig. 4a being inserted with the support structure in a compressed state;

[0112] Fig. 5b shows a longitudinal section view through the blood vessel according to Fig. 5a, with the supporting structure in an expanded state and covering the aneurysm;

[0113] Fig. 6 shows a schematic representation of the minimum distance between two openings in the wall of the support structure according to a preferred embodiment;

[0114] Fig. 7 shows a longitudinal sectional view through a rotary mold with a negative form for forming a medical device according to a preferred embodiment by means of a centrifugation process;

[0115] Fig. 8 shows a longitudinal section view through a rotary mold during the production of a support structure of the medical device according to the invention;

[0116] Fig. 9a shows a longitudinal section view through a blood vessel with a stenosis during the positioning of a medical device according to the invention using a balloon catheter;

[0117] Fig. 9b shows a longitudinal section view through the blood vessel according to Fig. 9a, with the support structure of the medical device expanded;

[0118] 102355-WO - MSP Keller Schneider

[0119] September 16, 2025 Patent and Trademark Attorneys Fig. 10a a longitudinal section view through a wall of a support structure of an implanted medical device abutting a vessel wall of a blood vessel with a stenosis, wherein the support structure is formed from two layers of material; and

[0120] Fig. 10b shows another longitudinal section view of the support structure according to Fig. 10a, the section passing through openings in the support structure.

[0121] Figure 1a schematically shows a portion of a prior art stent. The stent comprises a support structure 10 and is typically formed by laser cutting from a tubular blank. The laser cuts are preferably made in such a way as to expose webs 13, which are arranged in a substantially serpentine pattern. The webs 13 usually have an S-shaped base and are directly connected to one another or merge seamlessly or monolithically. The points where the webs 13 merge are called tips 14. Typically, rings are formed from several circumferentially adjacent webs 13, which are coupled to one another by tips 14, with several rings arranged consecutively along one longitudinal axis of the stent.These rings can be coupled by means of connectors, wherein the connectors preferably couple two longitudinally adjacent and mutually assigning tips 14 to each other.

[0122] Each web comprises a web width w and a web thickness t. Fig. 1b shows the ratio of web width w to web thickness t. The web thickness t simultaneously forms the wall thickness t of the support structure 10. In other words, the web thickness, or wall thickness t, extends in a radial direction with respect to the longitudinal axis of the support structure 10.

[0123] Fig. 1c shows the compression forces F acting on a web 13 when the support structure 10 is compressed. During compression, i.e., the transition from a radially expanded to a radially compressed state, bending forces act on the tips 14 (not shown in Fig. 1c). These provide a corresponding counterforce, regardless of whether the deformation is plastic or elastic. The in

[0124] 102355-WO - MSP Keller Schneider

[0125] September 16, 2025 Patent and trademark attorneys of the present application, however, the support structures 10 described mainly exhibit plastic deformation properties.

[0126] The compression described here occurs when the support structure 10 is compressed (crimped) onto a delivery system, for example, onto a balloon 42 of a balloon catheter 40. In this compressed state, the support structure 10, or the medical device, is guided into a body cavity, in particular a blood vessel 60, and expanded by the application of force. During expansion, forces again act on the support structure 10, which are now directed opposite to the compression forces F and cause plastic deformation of the webs 13 and tips 14 in the opposite direction. The expansion continues until contact is made with the vessel wall and is extended slightly beyond this point to widen the vessel wall beyond its original diameter. When the balloon 42 is subsequently deflated and removed, the support structure 10 is compressed inwards by the radially expanded blood vessel 60.The tips 13 are thus subjected to bending forces and oppose them with a counterforce, i.e., a bending resistance. The bending resistances of all tips 13 sum to a compression resistance of the supporting structure 10, which ensures that the blood vessel 60 does not compress further, i.e., that a predetermined minimum diameter of the body cavity is maintained.

[0127] As can be seen from Figures 1b and 1c, taking into account the theory of the behavior of a bending beam, the bending resistance is primarily determined by the web width w. Therefore, if the bending resistance is to be increased, it is advantageous to choose the largest possible web width w. At the same time, a small web thickness is beneficial with regard to blood flow. This reduces the formation of stagnation zones and turbulence, which can lead to the formation of thrombi. However, a high ratio between the web width w and the web thickness carries the risk of impairing the overall stability of the web 13. To prevent twisting of the web 13 under radial compression, a certain minimum web thickness or wall thickness t is therefore required. This leads to various disadvantages,

[0128] 102355-WO - MSP Keller Schneider

[0129] September 16, 2025 Patent and trademark attorneys, particularly with regard to the aforementioned influence on the flow within a hollow body organ, for example a blood vessel.

[0130] The medical devices according to the invention therefore utilize a support structure 10 whose wall thickness t changes, in particular is reduced, during the transition from the compressed state to the expanded state. Specifically, the medical device, in particular an endovascular implant, has a support structure 10 which has a wall with a wall thickness t. The wall thickness t is uniform, but variable, over the entire wall or support structure 10. In particular, the support structure 10 is configured such that a wall thickness t of the wall is reduced during the transition from the compressed state to an expanded state.

[0131] Fig. 2a shows such a support structure 10 in a side view, where the support structure 10 is in a compressed state. The compressed state can be partially or fully compressed. The support structure 10 can be partially or fully compressed immediately after manufacturing, i.e., in its manufacturing state. If the manufacturing state of the support structure 10 is partially compressed, the support structure 10 can be further compressed after manufacturing onto a balloon 42 of a balloon catheter 40. The compression is generally carried out in the radial direction.

[0132] The support structure 10 has a wall formed by a polymer material 11. The polymer material 11, or rather the wall, is perforated by several openings 12. In the embodiment shown in Fig. 2a, the openings 12 are essentially circular. Alternatively, the support structure 10a can be composed of webs 13 that define diamond-shaped openings 12. Essentially, four webs 13, arranged at angles to each other, can be provided to define an opening 12. In such a configuration, the support structure 10 forms a lattice-like structure.

[0133] Generally, within the scope of this application, areas of the wall of the

[0134] Support structure 10 formed with polymer material 11, i.e. areas that have openings 12

[0135] 102355-WO - MSP Keller Schneider

[0136] September 16, 2025 Patent and trademark attorneys surround or limit, referred to as “bridges” 13. This is independent of the shape of the openings. In particular, the openings may be in the form of pores or cells and may have a circular, oval, diamond-shaped or other form.

[0137] Fig. 2b shows the support structure 10 according to Fig. 2a in an expanded state. It can be seen that the stretching of the polymer material 11 also results in a distortion of the openings 12. Specifically, the openings 12 deform from their circular shape in the compressed state to an oval shape in the expanded state. The openings 12 extend with their main axis in the circumferential direction of the support structure 10.

[0138] Fig. 3a shows a sectional view of the wall of the support structure 10 in the compressed state according to Fig. 2a. The wall is formed by a polymer material 11 and is perforated by several circular openings 12. The wall has a thickness t.

[0139] Figure 3b shows the wall of the support structure 10 according to Figure 2b, where the support structure 10 is in its expanded state. It is clearly evident that the expansion causes elongation, which significantly reduces the wall thickness t. The support structure 10 is therefore thinner in its expanded state than in its compressed state. This results in less interference with fluid flows through the support structure 10 when it is expanded within a hollow body organ.

[0140] The medical device or the support structure 10 is preferably introduced via a balloon catheter 40. Such a balloon catheter 40 is shown in Figures 4a and 4b.

[0141] The balloon catheter 40 comprises a catheter shaft 41, at the distal end of which a balloon 42 is located. The balloon 42 can be pressurized via the catheter shaft 41, which has corresponding supply channels. This can be done using a liquid or a gas. Pressurizing the balloon 42 causes it to expand radially. The support structure 10 is located on the balloon 42.

[0142] 102355-WO - MSP Keller Schneider

[0143] On September 16, 2025, patent and trademark attorneys were ordered to act. An inner surface of the support structure 10 conforms to the outer surface of the balloon 42. In Fig. 4a, the support structure 10 is shown in a compressed state.

[0144] The balloon catheter 40 further comprises a guidewire 43, which may be guided into the balloon catheter 40 through a central channel. The guidewire 43 may exit the catheter shaft 41 at its tip. The guidewire 43 serves, in particular, to define a path for the balloon catheter 40 into a body cavity, especially a blood vessel. The guidewire 43 thus guides the balloon catheter 40 to the treatment site.

[0145] In the combined view of Figures 4a and 4b, it can be seen that the support structure 10, with a first wall thickness t, can be guided into a body cavity in its compressed state. Once the support structure 10 has reached the treatment site, the balloon 42 can be pressurized, causing it to expand. This exerts a radially outward expansion force on the support structure 10. The support structure 10 is thus expanded radially outward, resulting in plastic deformation of the polymer material 11. The wall thickness t of the support structure 10 is thereby reduced. Essentially, the polymer material 11 expands circumferentially. This material flows, which on the one hand reduces the wall thickness t and simultaneously increases the outer circumference of the support structure 10.

[0146] Figures 5a and 5b schematically show the placement of a support structure 10 in a blood vessel 60 containing an aneurysm 61, in particular an intracranial aneurysm 61. The aneurysm 61 is formed specifically in a bend of the blood vessel 60. The medical treatment goal is to largely isolate the aneurysm 61 from the blood flow, thereby reducing pressure on the vessel wall within the aneurysm 61. At the same time, however, a certain supply of nutrients to the vessel wall within the aneurysm 61 must be ensured to prevent rupture of the aneurysm 61.

[0147] 102355-WO - MSP Keller Schneider

[0148] September 16, 2025 Patent and Trademark Attorneys For this purpose, medical devices, in particular endovascular implants designed as stents or flow diverters, are preferably used. These can have a support structure 10 according to the invention, which is provided with openings 12. As can be seen in Fig. 5a, such a support structure 10 is first guided to the treatment site in the region of the aneurysm 61 via the balloon catheter 40. A fluid is then introduced into the balloon 42 of the catheter 40 via the catheter shaft 41, which builds up pressure in the balloon 42, leading to its expansion. This expands the support structure 10, causing it to conform to the blood vessel wall (Fig. 5b).

[0149] The support structure 10 has openings 12. Such openings are shown by way of example in Fig. 6. It can be advantageous if the openings 12 are located only at one edge of the support structure 10 in order to ensure blood flow into branching blood vessels while efficiently covering the aneurysm 61. Likewise, it can be advantageous if the openings 12 at the axial edge of the support structure 10 are larger or more pronounced than openings 12 in a central segment of the support structure 10. It is also conceivable that the support structure 10 has no openings 12. In that case, however, it is advantageous if the polymer material 11 is porous, in particular blood-permeable, to ensure a supply of nutrients to the vessel wall and the aneurysm 61.

[0150] Preferably, the support structure 10 is positioned so that it efficiently covers an access point to the aneurysm 61, a so-called aneurysm neck. The support structure 10 thus lies against the inner wall of the blood vessel 60 and bridges the access point to the aneurysm 61. Subsequently, the pressure is released from the balloon 42 of the balloon catheter 40, for example, by aspirating fluid from the balloon 42 via the catheter shaft 41. The balloon catheter 40 is then free and can be withdrawn from the blood vessel 60. The support structure 10, however, remains at the treatment site and prevents blood from continuing to enter the aneurysm 61 at high pressure or velocity.

[0151] 102355-WO - MSP Keller Schneider

[0152] September 16, 2025 Patent and Trademark Attorneys The medical device proposed here is designed to have a support structure 10 comprising several openings 12. These openings 12 can have different geometries. In any case, a minimum distance is maintained between two immediately adjacent openings 12 of the support structure 10. This minimum distance s is to be greater than the wall thickness t of the support structure 10. This ensures sufficient stability of the support structure 10. The medical device can be used to treat vascular segments with atherosclerotic changes or stenoses (narrowing of the vessels). Such changes or stenoses often occur in coronary arteries, the carotid artery, and peripheral or intracranial blood vessels 60.

[0153] The support structure 10 can have two material layers 11a, 11b. A higher number of material layers 11a, 11b is possible. An outer material layer 11a can contain pharmaceutical agents that are released when the medical device is implanted and diffuse into the vessel wall of the blood vessel 60. These agents may be particularly suitable for treating or alleviating inflammatory processes in the blood vessel 60.

[0154] At least one of the material layers 11a, 11b can be biodegradable. It is particularly advantageous if the outer material layer 11a, which also contains pharmaceutical active ingredients, is biodegradable. The biodegradation of the outer material layer 11a can thus contribute to a controlled, gradual release of the active ingredients.

[0155] Overall, the medical device, in particular the support structure 10, can have a mechanical and / or a fluid-dynamic and / or a purely protective function. A mechanical function can be provided by the wall of the support structure 10. The wall of the support structure 10 exhibits internal bending resistance and thus automatically resists deformation, in particular ovalization or waviness. In other words, the wall thickness t ensures the dimensional stability of the support structure 10. This also results in a radial resistance force, which, in the implanted state, ensures that the

[0156] 102355-WO - MSP Keller Schneider

[0157] September 16, 2025 Patent and Trademark Attorneys Support structure 10 opposes a narrowing of a blood vessel 60 and thus prevents further narrowing and possibly restenosis.

[0158] A fluid-dynamic and a protective function are achieved by the fact that the support structure 10, in its implanted state, conforms to a vessel wall, in particular by adhering to it. The fluid-dynamic function is particularly advantageous in the treatment of an aneurysm 61 and can, in particular, influence blood flow in or around an aneurysm 61. The protective function is demonstrated, in particular, by the fact that the support structure 10, for example, forms a filter that prevents tissue fragments or thrombi transported by the bloodstream from entering branching blood vessels 60. The implant can also prevent tissue fragments or thrombi from detaching from the vessel wall and entering the bloodstream. Such tissue fragments or thrombi can originate, for example, from calcified plaques or soft plaques. The delivery of active substances via the polymer material 11 of the support structure 10 is also a component of the protective function.

[0159] For the fluid-dynamic and protective functions of the support structure 10, the radial resistance plays only a minor role. What is more important is that the device remains positioned at the treatment site, particularly adhering to the vessel wall. The medical device described here fulfills these functions and can therefore be referred to as an endovascular plaster or, in English, as an "endovascular / intima(l) plaster," "endovascular / intima(l) patch," or "endovascular / intima(l) skin." It is advantageous to include this designation in the instructions for use or on the packaging of the medical device to explain its function more precisely.

[0160] The support structure 10 is preferably produced by a centrifugation process. This is illustrated by way of example in Fig. 7.

[0161] Fig. 7 shows in particular a rotary mold 55, on the inner circumferential wall 51 of which a negative mold 20 of the support structure 10 is attached. The negative mold 20 essentially forms a geometric shape complementary to the support structure 10.

[0162] 102355-WO - MSP Keller Schneider

[0163] September 16, 2025 Patent and Trademark Attorneys. The negative mold 20 has one or more recesses 22 on its inner circumference 21, which can be filled with a material, in particular the polymer material 11, to form the structural elements of the support structure 10. For this purpose, the rotary mold 55 is rotated and the polymer material 11 is introduced into the rotating rotary mold 55 or the rotating negative mold 20 via an injection needle 30. The injection needle 30 can be moved linearly to precisely position it at a predetermined location within the negative mold. At this position, the injection needle 30 can be held stationary while the polymer material 11 is introduced into the negative mold 20 via the injection needle 30.Alternatively, the injection needle 30 can be moved uniformly and linearly through the negative mold 20 during the introduction of the polymer material 11 to achieve a good and uniform distribution of the polymer material 11 within the negative mold 20. The recesses 22 of the negative mold 20 are thereby filled with the polymer material 11, which is deposited in the recesses 22 due to centrifugal forces. The rotation of the rotary mold 55 is preferably effected by a rotating shaft 52, which can be designed as a hollow shaft. The hollow shaft allows air to be guided from an inlet area 53 through the negative mold 20 and extracted via the hollow rotating shaft 52. Airflow in the opposite direction is also possible.

[0164] To produce the negative mold 20, a structured mandrel, whose mandrel essentially replicates the structure of the support structure 10, can be placed in a mold, leaving an annular space between the inner circumferential wall of the mold and the mandrel. This annular space can then be filled with an elastic material, such as silicone or a silicone-like material. After removing the mold and the structured mandrel, the elastic material remains as a negative mold for producing the support structure 10.

[0165] Fig. 8 illustrates the step of introducing the polymer material 11 into the negative mold 20 when the support structure 10 is to be formed from several layers with different polymer materials 11, 11'. Fig. 9 shows a cross-sectional view through a rotary mold 55, which has a rotating shaft 52 with a hollow channel 56.

[0166] 102355-WO - MSP Keller Schneider

[0167] September 16, 2025 Patent and Trademark Attorneys Opposite, an axial opening is provided as an inlet area 53. The hollow channel 56, together with the inlet area 53, allows air to flow through the rotary mold 55 to promote the evaporation of a solvent contained in the polymer materials 11, 11' and thus accelerate the curing of the polymer materials 11, 11'. Alternatively or additionally, the curing of the polymer material 11 can also be achieved by heat input, cooling, or a chemical reaction. The type of curing depends on the material used. Regardless of the type of curing, however, it is advantageous if this takes place under controlled environmental conditions, particularly with regard to temperature and humidity. For this purpose, the rotary mold 55 can be located in a closed chamber during the process.

[0168] A negative mold 20 is arranged in the rotary mold 55. The negative mold 20 can have arbitrarily structured projections 25 and channels 24 surrounding the projections 25 as recesses 22 (not shown in Fig. 8, but see Fig. 7). In the embodiment shown in Fig. 8, the negative mold 20 has an edge boundary 26 at each of its axial ends. The edge boundary 26 can, in particular, be formed by an annularly circumferential flange that extends radially inwards and thus forms the axial boundary for the support structure 10 to be produced. The annularly circumferential flange can be formed by a separate component or be an integral, in particular monolithic, part of the negative mold 20. It is also possible that the negative mold 20 has a smooth outer wall, in particular without outwardly projecting projections or flanges. It is also possible that the negative mold 20 is formed by the rotary mold 55.The negative mold 20 is therefore not necessarily a separate component; rather, the rotary mold 55 itself can form the negative mold 20 or be designed and functional as a negative mold 20.

[0169] Through the axial opening 54, an injection needle 30 is inserted into the negative mold 20 while the rotating mold 55 and thus also the negative mold 20 are rotating, so that one exit end of the injection needle 30 is positioned inside the rotating negative mold 20. Then, a polymer material 11 is injected into the rotating mold 20 via the injection needle 30.

[0170] 102355-WO - MSP Keller Schneider

[0171] September 16, 2025 Patent and Trademark Attorneys. Negative mold 20 is inserted. The polymer material 11 is deposited on the inside of the negative mold 20 under the influence of a centrifugal force. Subsequently, the process of feeding polymer material 11 is interrupted so that a solvent contained in the polymer material 11 can escape from the deposited first layer of the polymer material 11. During this time, the rotary mold 55 is preferably kept in rotation. In this way, the first layer of polymer material 11 at least partially hardens.

[0172] After the first layer of polymer material 11 has cured or at least partially cured, a further polymer material 11' is introduced into the negative mold 20 via the injection needle 30. For this purpose, the injection needle 30 can be held stationary or moved linearly and, in particular, coaxially through the negative mold 20. The further polymer material 11' can be different from the previously introduced polymer material 11. It is also conceivable that the further polymer material 11' is identical to the previously introduced polymer material 11. The further polymer material 11' is also deposited in the negative mold 20 under the influence of centrifugal force, forming a second layer on top of the first layer. In this way, a support structure 10 with two or more layers of different polymer materials 11, 11' can be produced.However, it is also possible to construct the support structure 10 from several layers of the same polymer material 11. By curing the polymer material 11 layer by layer, the mechanical properties of the support structure 10 or the speed of the manufacturing process can be positively influenced, for example.

[0173] Figures 9a and 9b illustrate the process of inserting a medical device according to the invention into a blood vessel 60. The blood vessel 60 has a vessel wall 62 in which a stenosis 63 has formed due to tissue changes. The stenosis 63 leads to a reduction in the flow cross-section and a stiffening of the vessel wall 62, which impairs blood flow. The medical device is inserted to restore the flow diameter required for good blood flow.

[0174] 102355-WO - MSP Keller Schneider

[0175] September 16, 2025 Patent and Trademark Attorneys The medical device comprises a support structure 10, which can be configured as described above. The support structure 10 is arranged in a compressed state on a balloon 42 of a balloon catheter 40 and is guided through the blood vessel 60 by means of the balloon catheter to the location of the stenosis 63 (Fig. 9a). Once the support structure 10 is positioned in the region of the stenosis 63, the balloon 42 is filled with a fluid and thus radially expanded under the influence of the fluid pressure. This also causes the support structure 10 to expand radially, whereby the support structure 10 plastically deforms and conforms to the vessel wall 62. By maintaining or increasing the fluid pressure in the balloon 42, the expansion of the support structure 10 continues, dilating the stenosis 63.This is usually performed under X-ray guidance, which is why the fluid typically contains a contrast agent. Once the desired flow diameter is set, the balloon 42 is depressurized and thus shrinks back to the catheter shaft 41. The plastically deformed support structure 10 retains its cross-sectional diameter and thus supports the blood vessel 60, so that it remains open in the area of ​​the stenosis 63 (Fig. 9b). Due to the plastic deformation, the support structure 10 has a smaller wall thickness t in the implanted state according to Fig. 9b than in the compressed state according to Fig. 9a. It is clearly visible in Fig. 9b that the support structure 10 fits closely to the vessel wall 62 and at least partially follows its course.

[0176] It should be noted that the wall thickness t in the accompanying drawings is not shown to scale with respect to the compressed and expanded states. Rather, the wall thickness in the expanded state is shown particularly pronounced for the sake of clarity.

[0177] Figures 10a and 10b show a partial section through an implanted support structure 10, which is composed of two material layers 10a, 10b. The support structure 10 comprises, in particular, an outer material layer 10a, which lies directly against the vessel wall 62. An inner material layer 10b is in direct contact with the blood flowing through the blood vessel 60.

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[0179] September 16, 2025 Patent and Trademark Attorneys The longitudinal section according to Fig. 10a passes through a region of the support structure 10 that is completely closed in the longitudinal direction, i.e., any openings 12 are located outside the cut edge. For example, the support structure 10 can comprise several circular openings 12, these being arranged in a regular, in particular pattern-like, pattern in rows along the longitudinal axis of the support structure 10. Between them is the region shown in the section, in which only polymer material 11 is present, in particular the two material layers 11a, 11b, each comprising a polymer material 11. The outer material layer 11a can be biodegradable and carry at least one pharmaceutical active ingredient, the active ingredient being embedded in the polymer material 11 of the outer material layer. Alternatively, the longitudinal section according to Fig. 10 can pass through a support structure 10 that has no openings 12.

[0180] The longitudinal section according to 10b, however, runs through a region of the support structure 10 that is interrupted by openings 12. It can be seen that the openings 12 completely penetrate the wall, in particular the two material layers 11a, 11b. The region with openings 12 can occupy part of the circumference of the support structure 10, whereas another part of the circumference of the support structure 10 is formed without openings. This can be advantageous if the part without openings 12 is to be used, for example, to cover an aneurysm that is located opposite a branching blood vessel 60. The part of the support structure 10 with the openings can then be positioned so that the openings 12 allow blood flow into the branching blood vessel 60. However, as shown in Fig. 10b, the openings 12 can also serve to further supply the vessel wall 62 with nutrients.Likewise, it can be advantageous if the openings 12 are of different shapes along the circumference or length of the support structure 10.

[0181] 102355-WO - MSP Keller Schneider

[0182] September 16, 2025 Patent and Trademark Attorneys Reference List

[0183] 10 Support structure

[0184] 11 Polymer material

[0185] 11' further polymer material

[0186] 11a outer material layer

[0187] 11 b inner material layer

[0188] 12 Opening

[0189] 13 Bridge

[0190] 14 top

[0191] 20 negative molds

[0192] 21 Inner circumference

[0193] 22 In-depth study

[0194] 24-channel

[0195] 26 Edge boundary

[0196] 27 lead

[0197] 30 injection needles

[0198] 31 Linear drive

[0199] 40 balloon catheters

[0200] 41 Catheterization

[0201] 42 Balloon

[0202] 43 Guide wire

[0203] 51 Inner perimeter wall

[0204] 52 Rotary shaft

[0205] 53 Entrance area

[0206] 55 Rotary Mold

[0207] 56 Hollow channel

[0208] 102355-WO - MSP Keller Schneider

[0209] September 16, 2025 Patent and Trademark Attorneys 60 Blood Vessel

[0210] 61 Aneurysm

[0211] 62 Vessel wall

[0212] 63 Stenosis F Bending force s Minimum distance t Wall thickness w Web width

[0213] 102355-WO - MSP Keller Schneider

[0214] September 16, 2025 Patent and Trademark Attorneys

Claims

39 Patent claims 1. Medical device for the treatment of body hollow organs, in particular an endovascular implant, with a tubular support structure (10) having a wall with a substantially uniform wall thickness t and being convertible from a radially compressed state to a radially expanded state, characterized in that the support structure (10) is adapted to deform plastically during the transition from the compressed state to the expanded state in such a way that the wall thickness t of the wall decreases, in particular uniformly.

2. Medical device according to claim 1 characterized in that the support structure (10) comprises or is formed from at least one polymer material.

3. Medical device according to claim 2 characterized in that the polymer material comprises polycaprolactone (PCL), polylactides (PLA, PLLA), polyurethanes and / or hydrogels, in particular polyvinyl alcohols (PVA), gelatin, collagen or elastin.

4. Medical device according to one of the preceding claims characterized in that the wall in a manufacturing state, in particular in the radially compressed state of the support structure (10), has a uniform wall thickness t, wherein a ratio between the wall thickness t of the wall in the radially expanded state of the support structure (10) and the wall thickness t of the wall in the radially compressed state of the support structure (10) is at most 50%, in particular at most 30%, in particular at most 20%, in particular at most 10%. 102355-WO - MSP Keller Schneider September 16, 2025 Patent and Trademark Attorneys 40 5. Medical device according to one of the preceding claims characterized in that the wall, with a cross-sectional diameter of the support structure (10) in the radially expanded state between 3 mm and 6 mm, in particular between 3.5 mm and 5 mm, preferably 4 mm, has a wall thickness of at most 30 pm, in particular at most 20 pm, in particular at most 10 pm.

6. Medical device according to one of the preceding claims characterized in that the support structure (10), in particular the wall, has patterned openings (12), wherein the openings (12) in a manufacturing state, in particular in the radially compressed state, of the support structure (10) are circular, slit-shaped or polygonal, in particular diamond-shaped.

7. Medical device according to claim 6 characterized in that the slot-shaped openings (12) extend parallel to a longitudinal axis of the support structure (10), along a circumferential direction of the support structure (10) and / or obliquely to the longitudinal axis and to the circumferential direction.

8. Medical device according to one of the preceding claims characterized in that a minimum distance s between two openings (12) of the wall in the radially expanded state of the support structure (10) is greater than the wall thickness in the radially expanded state of the support structure (10).

9. Medical device according to claim 8 characterized in that the ratio between the wall thickness t and the minimum distance s in the expanded state of the support structure (10) is less than 80%, in particular less than 60%, in particular less than 40%, in particular less than 20%. 102355-WO - MSP Keller Schneider September 16, 2025 Patent and Trademark Attorneys 41 10. Medical device according to one of the preceding claims characterized in that the wall has at least two material layers with different properties.

11. Medical device according to claim 10 characterized in that the polymer material (11) is biodegradable, in particular wherein the material layers are biodegradable and have different degradation rates.

12. Medical device according to claim 11 characterized in that a pharmaceutical active ingredient is embedded in the polymer material (11), in particular at least one of the material layers, in particular wherein a material layer with a pharmaceutical active ingredient forms an outer layer of the support structure (10).

13. Method for manufacturing a medical device according to any of the preceding claims, the method comprising the following steps: a) providing a negative mold (20) having at least one recess (22) on an inner circumference (21) forming a negative structure of a support structure (10), b) rotating the negative mold (20) about a central axis of rotation, c) introducing a polymer material (11) into the rotating negative mold (20) such that the polymer material (11) is deposited into the recess (22) under the influence of a centrifugal force, d) curing the polymer material (11) under rotation of the negative mold (20) to form the support structure (10), and e) removing the support structure (10) from the negative mold (20). 102355-WO - MSP Keller Schneider September 16, 2025 Patent and Trademark Attorneys 14. The method of claim 13, characterized in that the provision of the negative mold (20) according to step a) comprises the following steps: i. generating a rotationally symmetric mandrel having at least one projection on an outer surface forming a positive structure of the support structure (10), ii. positioning the mandrel in a mold, wherein the mandrel is aligned coaxially to the mold and an annular space remains between the mandrel and an inner circumferential wall of the mold, iii. filling the annular space with a molding material to form the negative shape (20) of the support structure (10), and iv. removing the mandrel from the mold.

15. A method for manufacturing a medical device according to any one of claims 1 to 12, wherein the method comprises the following steps: a) providing a cylindrical, electrically conductive collector and a deposition nozzle; b) applying a voltage between the electrically conductive collector and the deposition nozzle; c) expelling a polymer material from the nozzle so that a polymer thread forms between the collector and the deposition nozzle; and d) depositing the polymer thread, preferably in a helical form, around the cylindrical, electrically conductive collector. 102355-WO - MSP Keller Schneider September 16, 2025 Patent and Trademark Attorneys

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