DE102019121559A1 - Medical device for insertion into a hollow body organ and method for producing a medical device - Google Patents

Abstract

The invention relates to a medical device (2), in particular an occlusion device, for insertion into a hollow body organ with a compressible and expandable lattice structure (10) made of lattice elements (11, 12, 13, 14) which form cells (15), the lattice structure ( 10) comprises at least some sections of a cover (16) made of an electrospun fabric, the cover (16) having such a porosity that the cover (16) in an implanted state of the lattice structure (10) allows the blood flow in the hollow body organ through the lattice structure (10) ) in the area of the cover (16). The invention also relates to a method for producing such a medical device.

Description

The invention relates to a medical device for insertion into a hollow body organ according to the preamble of patent claim 1. The invention also relates to a manufacturing method. A medical device of this type is, for example, derived from that which goes back to the applicant WO 2014/177634 A1 known.

The previously known medical device describes a highly flexible stent which has a compressible and expandable lattice structure, the lattice structure being formed in one piece. The lattice structure comprises closed cells which are each delimited by four lattice elements. The lattice structure has at least one cell ring which comprises between three and six cells.

In addition, stents with lattice structures which are formed from a single wire are known from the applicant's practice. The wire is intertwined with itself to form a tubular braid. The wire is deflected at the axial ends of the tubular braid so that atraumatic loops are formed. The axial ends can be widened in a funnel shape.

The known medical device is particularly suitable for treating aneurysms in small, cerebral blood vessels. Such blood vessels have a very small cross-sectional diameter and are often very tortuous. The known stent is designed to be highly flexible for this purpose, so that on the one hand it can be compressed to a very small cross-sectional diameter and on the other hand it has a high degree of bending flexibility, which enables it to be fed into small cerebral blood vessels.

To treat aneurysms in cerebral blood vessels, it is useful to use stents that stretch over an aneurysm and shield it from the blood flow within the blood vessel. In order to make this possible, it is known to provide stents with a cover which closes the cells of the stent and thus prevents blood from flowing into an aneurysm. Such covers are often made from textile materials. In combination with the stent structure, however, this results in a relatively high wall thickness of the stent, which in turn limits the compressibility of the stent. The cover thus limits the compression to a small cross-sectional diameter, which in turn hinders the delivery of the stent into small cerebral blood vessels. The one going back to the applicant EP 2 946 750 B1 tries to solve the compressibility of a stent with a textile covering by providing fiber strands of the textile material from loosely arranged individual filaments.

Textile-like structures which are suitable for covering aneurysms are known from the prior art. In particular shows EP 2 546 394 A1 such a cover, a so-called graft, which has an electrospun structure. In order to achieve a particularly low porosity, several layers of this electrospun structure are superimposed. However, this leads to a high wall thickness, which is a hindrance when feeding into small, strongly curved blood vessels.

Out WO 02/49536 A2 an electrospun structure is also known which comprises two layers of electrospun fabric, the two layers having different porosities. Here, too, the wall thickness is relatively large and thus limits the compressibility of the electrospun structure.

EP 2 678 446 B1 deals with a stent for neurovascular applications which is covered with a non-woven fabric. The nonwoven fabric is produced by electrospinning and comprises several layers, an inner layer being impermeable to liquids and an outer layer being spongy. The fiber fleece thus forms a very difficult liquid-permeable membrane and, because of the sponge-like layer, has an increased wall thickness, which impairs the compressibility of the sten.

The invention is based on the object of specifying a medical device for insertion into a hollow body organ which can be compressed to a very small extent and at the same time provides good shielding of an aneurysm. Furthermore, the object of the invention is to provide a manufacturing method.

According to the invention, this object is achieved with regard to the medical device by the subject matter of claim 1 and with regard to the manufacturing method by the subject matter of claim 16.

Specifically, the object is achieved by a medical device, in particular by an occlusion device, for insertion into a hollow body organ, in particular into a blood vessel, with a compressible and expandable lattice structure made of lattice elements. The grid elements are connected to one another in one piece and form cells. In the following, the terms hollow body organ and (blood) vessel are used simultaneously.

According to the invention it is provided that the lattice structure at least in sections Cover made of an electrospun fabric, wherein the cover has such a porosity that the cover, in an implanted state of the lattice structure, interrupts the blood flow in the hollow body organ through the lattice structure in the area of the cover.

In an electrospun fabric, pores are usually irregular in shape. In any case, the manufacturing process does not allow a pattern-like arrangement or design of pores to be created. However, the pore sizes can be adjusted using the process parameters at least to such an extent that it is ensured that at least some of the pores have a certain minimum size.

For example, the electrospinning process can take place directly on the lattice structure, so that a connection to the lattice structure is simultaneously established when the cover is formed.

The invention has the advantage that it combines a highly flexible lattice structure as a carrier structure with a cover which, due to its manufacturing process, is particularly thin and flexible. In this respect, the medical device is altogether highly compressible and can be easily inserted into very small blood vessels. The high flexibility of the support structure or the lattice structure is due to the very small pore size of the pores of the cover. Overall, the small pores lead to the formation of a thin wall thickness of the cover and thereby enable the lattice structure to be compressed to a very small cross-sectional diameter.

With the medical device according to the invention, treatments in blood vessels are therefore also possible that cannot be achieved with previous medical devices that have a lattice structure and a cover. This is particularly relevant for the treatment of aneurysms in cerebral blood vessels, for which the invention is particularly suitable. In particular, interruption of the blood flow through such blood vessels is made possible, for example in order to treat an aneurysm that has formed there.

Because of the high compressibility of the device according to the invention, very low feeding forces occur when feeding through a catheter. The material of the cover can also contribute to reducing the feed forces. In particular, in the case of the device with a cover, the feed forces can be the same or less than when the grid structure is fed in alone.

The highly flexible lattice structure as a support structure has the further advantage that the lattice structure can be pulled back into a catheter, e.g. after a temporary placement inside the blood vessel, since no lattice elements protrude due to the cover that could get caught on a catheter tip.

Preferred embodiments of the invention are specified in the subclaims.

In a preferred embodiment, the cover covers at least 70%, in particular at least 80%, in particular at least 90% of a cross-sectional area of the hollow body organ, in particular the blood vessel. This achieves a reliable reduction and, in particular, a reliable interruption of the blood flow through the hollow body organ. The latter is almost achieved in particular when the cover covers at least 90% of the cross-sectional area of the hollow body organ.

In order to further improve the interruption of the blood flow through the cover in the expanded state of the lattice structure, in a further preferred embodiment at least 60%, in particular at least 70%, in particular at least 80% of the area of the cover is formed by pores. These preferably have an inscribed circle diameter of at least 30 μm. The inscribed circle diameter is the diameter of the largest possible circle that can be inscribed in the pore. In other words, the inscribed diameter of the pore corresponds to the outer diameter of a cylinder that can just about be pushed through the pore.

The minimum size of the pores can be adjusted in the course of the production of the cover and has a significant influence on the compressible cross-sectional diameter and the bending flexibility of the lattice structure. A cover made from an electrospun fabric is extremely thin and flexible, so that the flexibility of the lattice structure is supported. The formation of very small pores barely prevents the cover from compressing the lattice structure, in contrast to previously known covers made from other textile materials. Overall, the entire medical device according to the invention can thus be compressed to a considerably smaller cross-sectional diameter and thus guided into particularly small blood vessels via small catheters.

The pores preferably have a size of at most 750 μm ² , in particular of at most 500 μm ² , in particular of at most 300 μm ² . This ensures that the permeability of the cover is not too great, so that a medical meaningful interruption of the blood flow through the body's hollow organ and thus a meaningful shielding of the aneurysm from the blood flow in the vessel is achieved.

The advantages of the present invention are further improved if the cover comprises at least 15 pores on an area of 100,000 μm ² , which are at least 30 μm ² , in particular at least 50 μm ² , in particular at least 70 μm ² , in particular at least 90 μm ² , exhibit. It is also beneficial if the cover comprises at least 15, in particular at least 20, in particular at least 25, pores over an area of 100,000 μm ² , which have a size of at least 30 μm ² .

The flexibility of the cover or the lattice structure is increased in that the cover is preferably formed from threads arranged in an irregular network-like manner and having a thread thickness between 1 μm and 2 μm.

The cover is preferably arranged on an outside and / or inside of the lattice structure. In the event that the cover is arranged on an outside of the lattice structure, the lattice structure forms a support structure which applies a sufficient radial force to fix the cover against a vessel wall. The carrier structure supports the cover arranged on the outside. Alternatively, the cover can also be arranged on an inside of the lattice structure. In particular, it is possible for the lattice structure to be embedded between two covers which are each formed by an electrospun fabric. The lattice elements of the lattice structure can in this respect be completely encased by the electrospun fabric. Specifically, it can be provided that the electrospun fabric of a cover on the inside of the lattice structure extends through the cells of the lattice structure and is connected to the electrospun fabric of a cover on the outside of the lattice structure. The grid elements that delimit the cells are encased on all sides by electrospun tissue.

In a preferred embodiment, the cover is irreversibly connected to the lattice structure, in particular in a materially bonded manner. The irreversible connection between the cover and the grid structure prevents the cover from becoming detached from the grid structure, for example when the medical device is fed through a catheter.

The cover is preferably formed from a plastic material, in particular a polyurethane. Such materials are particularly light and can be easily produced in fine threads using an electrospinning process. On the one hand, the plastic material enables a particularly thin and fine-pored cover to be produced. On the other hand, the plastic material already has a high degree of flexibility, so that the medical device can be compressed to a high degree. Alternatively, the cover can also be formed by polyethylene and / or by fluoropolymers or by, for example, polycarbonate-based, thermoplastic polyurethanes. Furthermore, for example, it can additionally be provided that fillers, such as anti-thrombogenic substances, are embedded in the aforementioned materials of the cover after the electrospinning process.

The cover preferably has a blood-permeable and a blood-impermeable area. This has the advantage that the medical device in the expanded state enables both a supply of nutrients into the aneurysm and, at the same time, good shielding of the aneurysm. Furthermore, a supply of nutrients into branching blood vessels and adjacent inner walls of the vessels is also possible. The blood permeability of the cover is useful in order to supply the cells of the aneurysm wall with nutrients, so that a degeneration of the cells and a possible rupture of the aneurysm resulting therefrom is avoided. Specifically, the blood-impermeable area is preferably formed by the cover. The blood-permeable area is here preferably formed by the partial area of the surface of the lattice structure that is not covered by the cover. Alternatively or in addition, the blood-permeable area can be formed by the sub-area of the cover that is not formed from the pores already mentioned. For example, the blood-impermeable area can thus be formed by the remaining 40% of the area of the cover if 60% of the area of the cover - as already explained above - is formed by pores.

In a preferred embodiment, the cover has X-ray-visible markers, in particular X-ray-visible sleeves, for example made of patina or gold, at least at the longitudinal ends. This facilitates the positioning of the medical device under an X-ray control. Since the cover is irreversibly connected to the lattice structure, in particular in a materially bonded manner, the relative position between the cover and the lattice structure is constant. No additional X-ray markers, which would make a relative displacement between the cover and the lattice structure recognizable, are therefore required. Overall, the number of X-ray markers, for example X-ray marker sleeves, can be reduced, which in turn has a positive effect on the compressibility of the medical device result.

In order to increase the stability of the lattice structure, in a preferred embodiment the lattice elements are encased by an adhesion promoter, in particular polyurethane, the adhesion promoter preferably forming the material connection between the cover and the lattice structure.

The lattice elements preferably form webs which are coupled to one another in one piece by web connectors, or wires which are interwoven. A lattice structure formed in one piece has a comparatively thin wall thickness, so that as a result the blood flow within a blood vessel is less strongly influenced. A braided lattice structure, on the other hand, is characterized by a particularly high flexibility, in particular bending flexibility. Furthermore, lattice structures that are formed from a wire mesh are more cost-effective to produce than lattice structures that are made from one piece.

In a preferred embodiment of the invention it is provided that the lattice structure at least in sections forms a cylindrical and / or funnel-shaped hollow body. An essentially cylindrical hollow body enables the lattice structure to rest against the vessel walls of a blood vessel. A funnel-shaped hollow body can be used, for example, to catch thrombi within a blood vessel or to treat vessels with varying diameters. In the case of a funnel-shaped hollow body, the axial ends of the lattice structure can be designed to be radially widened (flaring), in particular funnel-shaped or radially tapered, in particular conical. The flaring angle can preferably be between 50 ° and 70 °, in particular between 55 ° and 65 °. In this context, funnel-shaped can be understood to mean both a rotationally symmetrical cross-sectional contour and, alternatively, a non-rotationally symmetrical cross-sectional contour.

In a preferred embodiment, the medical device is arranged in a compressed state on or on a transport wire so that the medical device can be axially displaced within a feed tube (also referred to as an insertion aid), the feed tube expediently having an inner diameter of at most 5 μm. The arrangement of the medical device on or on the transport wire is reversible or irreversible. In one embodiment, this enables the medical device to be used as a permanent implant, in particular in the form of a permanently implantable stent, when the medical device is arranged reversibly on the transport wire. For this purpose, after the medical device has been placed inside the blood vessel, the reversible arrangement with the transport wire is released and the wire is removed from the vessel. In an alternative embodiment to this, the medical device can be used as a thrombectomy device in the case of an irreversible arrangement on or on the transport wire, the thrombectomy device preferably only being released temporarily in a blood vessel and being removed again from the vessel after treatment with the transport wire.

The medical device is preferably precisely compatible with a 2Fr catheter. Precisely fitting compatibility means that a relative movement between the medical device and such a 2Fr catheter is possible in the axial direction. For this purpose, a minimal gap or play is provided between the outer diameter of the medical device and the inner diameter of the catheter used in use. In other words, the outer diameter of the medical device has, for example, a value that is 0.05 mm to 0.1 mm smaller than the inner diameter of the catheter used in use. The advantage of the perfectly fitting compatibility with a 2Fr catheter is that the transport wire and the catheter body form a very compact unit in use, so that relative movements between the transport wire and the catheter body in the radial direction, i.e. perpendicular to the guide wire, are practically avoided. This in turn enables the catheter to be precisely navigable and guided with little resistance.

1. a. Bereitstellen einer komprimierbaren und expandierbaren Gitterstruktur aus Gitterelementen, die geschlossene Zellen der Gitterstruktur begrenzen ;
2. b. Beschichten der Gitterstruktur mit einem Haftvermittler, insbesondere aus Polyurethan; und
3. c. Aufbringen einer Abdeckung auf die Gitterstruktur durch einen Elektrospinnprozess.

A secondary aspect of the invention relates to a method for producing a medical device for insertion into a hollow body organ. In particular, within the scope of the application, a method for producing a medical device having the aforementioned features is disclosed and claimed. In general, the method according to the invention comprises the following steps:

1. a. Providing a compressible and expandable lattice structure made of lattice elements which delimit closed cells of the lattice structure;
2. b. Coating the grid structure with an adhesion promoter, in particular made of polyurethane; and
3. c. Applying a cover to the lattice structure using an electrospinning process.

In the method according to the invention, the cover is produced directly on the lattice structure. In order to achieve a firm connection between the lattice structure and the cover, a Adhesion promoter used, which is preferably formed from a biocompatible plastic. The adhesion promoter acts as an adhesive and connects the cover irreversibly, i.e. firmly, to the grid structure. It has been found to be particularly advantageous if polyurethane is used as the adhesion promoter.

It is preferably provided that the coating of the lattice structure with the adhesion promoter takes place by means of a dip coating process. Such a process can be carried out particularly quickly and easily and is characterized by a high level of process reliability. For this purpose, the lattice structure is immersed in a vessel filled with the adhesion promoter, so that the adhesion promoter rests against the lattice elements of the lattice structure. The cells of the lattice structure generally remain free of an adhesion promoter and are therefore not closed by the adhesion promoter.

A particularly effective fixing of the cover on the lattice structure is achieved in a preferred variant of the method according to the invention in that the adhesion promoter and the cover each have a plastic material. The two plastics of the adhesion promoter and the cover easily connect to one another, so that there is a firm connection to the grid structure. This is particularly effective if the plastic material, as provided in preferred variants, comes from the same group of materials. In particular, both the adhesion promoter and the cover can be formed from polyurethane.

The advantages and preferred refinements listed with regard to the medical device can be applied analogously to the method and vice versa.

• 1: eine perspektivische Darstellung einer Gitterstruktur einer erfindungsgemäßen medizinischen Vorrichtung nach einem bevorzugten Ausführungsbeispiel.

The invention is explained in more detail below on the basis of an exemplary embodiment with reference to the accompanying illustrations. It shows:

• 1 : a perspective illustration of a lattice structure of a medical device according to the invention according to a preferred embodiment.

The attached figure shows a medical device 2 which is suitable for introduction into a hollow body organ. The medical device 2 has a lattice structure in particular 10 that is compressible and expandable. In other words, the lattice structure 10 assume a feeding state in which the lattice structure 10 has a relatively small cross-sectional diameter. The lattice structure 10 is preferably self-expanding, so that the lattice structure 10 automatically expands to a maximum cross-sectional diameter without the influence of external forces. To this end, the lattice structure 10 preferably a memory alloy or is formed from such a material. The state in which the lattice structure 10 has the maximum cross-sectional diameter corresponds to the expanded state. In this state the lattice structure exercises 10 no radial forces.

1 shows the lattice structure 10 in the expanded state. It can be clearly seen that the lattice structure 10 is essentially cylindrical. It is also possible that the lattice structure 10 in sections has a geometry different from a cylindrical shape. For example, the lattice structure 10 be funnel-shaped at least at a proximal end.

In 1 exhibits the lattice structure 10 three areas. A middle area 20th , a first axial area 21st and a second axial section 22nd . The middle area 20th includes a cover 16 that are on the outside of the lattice structure 10 is arranged. It is possible that the cover 16 also on the inside of the lattice structure 10 is arranged. The cover 16 spans the entire lattice structure 10 and in particular covers cells 15th . The cover 16 can extend along the entire lattice structure 10 or only extend in areas.

For example, an axial area or both axial areas 21st , 22nd the lattice structure 10 be uncovered, as shown in 1 is shown.

Furthermore, the lattice structure 10 in sections a different cross-sectional diameter. The lattice structure is concrete 10 or the cover 16 in the middle area 20th funnel-shaped, ie it has a taper 23 in the middle area 20th on. It is possible that the lattice structure 10 or the cover 16 in the middle area 20th and / or in one of the axial areas 21st , 22nd is formed conically tapering or conically widening. It is possible that the lattice structure 10 or the cover 16 in the middle area 20th and / or in one of the axial areas 21st , 22nd has a round, elliptical or other spherical shape. In other words, the lattice structure 10 in the embodiment according to 1 in a side view a geometry in the manner of an hourglass. In an alternative embodiment, the lattice structure 10 multiple tapers 23 have in the axial direction.

Such a configuration is advantageous in medical devices which are used as thrombus collectors or generally as thrombectomy devices. The lattice structure 10 can in such cases essentially form a basket-like structure.

The lattice structure 10 is formed in one piece. The lattice structure 10 is preferably made from a tubular blank, for example by laser cutting. Individual grid elements or webs are thereby used 11 , 12 , 13 , 14th the lattice structure 10 exposed by the laser cutting processing. The areas removed from the blank form cells 15th the lattice structure 10 . From one bar connector each 17th go four bars each 11 , 12 , 13 , 14th off, each ridge 11 , 12 , 13 , 14th two cells each 15th assigned. The bridges 11 , 12 , 13 , 14th each limit the cells 15th .

The uncovered areas 21st , 22nd also enable good coupling to a transport wire 19th . They also provide the edge cells attached to a cover 16 hardly participate in an aneurysm anyway, but rather should effect an anchoring in a blood vessel, in this way a high permeability, so that the inner walls of the vessel are well supplied with nutrients in this area.

The cover 16 is made of an electrospun fabric and is therefore characterized by a particularly thin wall thickness. At the same time is the cover 16 sufficiently stable to allow expansion of the lattice structure 10 to follow.

The cover 16 has a large number of different sizes and pores, ie completely free through openings. The pores are not shown in the figures. The cover 16 has such a porosity that it is in an implanted state of the lattice structure 10 substantially completely covers or fills the inner cross-section of a hollow body organ, in particular a blood vessel. In other words it is the cover 16 completely closed in cross section. The porosity is set such that the cover 16 on the one hand forms an almost complete barrier against a flow and on the other hand simultaneously allows the passage of nutrients and a feed wire. In particular, the cover covers at least 70%, in particular at least 80%, in particular at least 90% of a cross-sectional area of the hollow body organ, in particular the blood vessel.

An interruption can also be understood as a slow process. Even if only a reduction in flow occurs at the beginning, the deposition of proteins and blood components ensures complete closure in the long term, preferably in a few minutes, in particular in a few days.

The cover 16 is preferably complete and irreversible with the lattice structure 10 connected. The coverage is specific 16 preferably with the bars 11 , 12 , 13 , 14th glued, for example by an adhesion promoter, which is applied to the lattice structure by a dip coating process 10 was applied.

It is possible for the adhesion promoter, which is preferably applied to the lattice structure by the aforementioned dip-coating process, to be essentially form-fitting on the lattice structure 10 adheres. The cover 16 then, because of the plastic material of the material group, preferably integrally connects with the adhesion promoter. Overall, there is such an irreversible connection between the lattice structure 10 and the cover 16 produced.

It is also possible to apply the cover 16 on the lattice structure 10 a laser cutting process follows through the electrospinning process. Specifically, the pores of the cover 16 can be post-processed using laser cutting. In particular, it is conceivable to individually adapt the pore shape and / or the pore size by means of a laser cutting process. The pore size of individual pores can, for example, be increased in a targeted manner. Furthermore, the cover 16 be structured overall, in particular by the laser cutting process. In the middle area 20th the cover 16 or the lattice structure 10 Openings can also be made, in particular by means of laser cutting, in order, for example, to enable blood to flow into branching blood vessels.

The electrospinning process creates several threads that are irregularly aligned with one another. This creates pores. In order to enable sufficient flexibility and easy feedability of the medical device into very small blood vessels, it is necessary that the threads have a thread diameter between 1 μm and 2 μm so that pores with comparatively small pore sizes are formed. However, some pores can be sufficiently large to ensure blood permeability. Specifically, the pores have a diameter of at least 31 µm.

A special feature of the electrospinning process is that it is covered 16 There are places at which only, ie not more than, two threads cross one another. This has the consequence that the cover 16 overall has a very thin wall thickness and is therefore highly flexible.

The high flexibility of the cover 16 in combination with the high flexibility of the lattice structure 10 results in a medical device being able to be inserted into a blood vessel through very small delivery catheters. In particular, delivery catheters can be used which have a size of 2 French.

To have good visibility of the cover 16 To allow under an X-ray control, the cover has 16 an X-ray marker at each axial end 18th on. Specifically, the X-ray markers 18th be formed as X-ray visible sleeves, for example made of platinum or gold.

List of reference symbols

2

medical device

10

Lattice structure

11

Lattice element

12

Lattice element

13

Lattice element

14th

Lattice element

15th

cell

16

cover

17th

Bar connector

18th

X-ray marker

19th

Transport wire

20th

middle area

21st

first axial area

22nd

second axial area

23

rejuvenation

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• WO 2014/177634 A1 [0001]
• EP 2946750 B1 [0005]
• EP 2546394 A1 [0006]
• WO 0249536 A2 [0007]
• EP 2678446 B1 [0008]

Claims (18)

Medical device (2), in particular occlusion device, for insertion into a hollow body organ with a compressible and expandable lattice structure (10) made of lattice elements (11, 12, 13, 14) which form cells (15), characterized in that the lattice structure (10 ) at least in sections comprises a cover (16) made of an electrospun fabric, the cover (16) having such a porosity that the cover (16) in an implanted state of the lattice structure (10) allows the blood flow in the hollow body organ through the lattice structure (10) interrupts in the area of the cover (16). Medical device according to Claim 1 , characterized in that the cover (16) in the expanded state of the lattice structure (10) covers a cross-sectional area of the hollow body organ to at least 70%, in particular at least 80%, in particular at least 90%. Medical device according to Claim 1 or 2 , characterized in that at least 60%, in particular at least 70%, in particular at least 80% of the area of the cover (16) is formed by pores which have an inscribed circle diameter of at least 30 µm. Medical device according to one of the preceding claims, characterized in that the pores have a size of at most 750 µm ² , in particular of at most 500 µm ² , in particular of at most 300 µm ² . Medical device according to one of the preceding claims, characterized in that the cover (16) is formed from threads arranged in an irregular network-like manner and having a thread thickness between 1 µm and 2 µm. Medical device according to one of the preceding claims, characterized in that the cover (16) is arranged on an outside and / or inside of the lattice structure (10). Medical device according to one of the preceding claims, characterized in that the cover (16) is connected to the lattice structure (10) irreversibly, in particular in a materially bonded manner. Medical device according to one of the preceding claims, characterized in that the cover (16) is formed from a plastic material, in particular from a polyurethane. Medical device according to one of the preceding claims, characterized in that the cover (16) has a blood-permeable and a blood-impermeable area. Medical device according to one of the preceding claims, characterized in that the cover (16) has x-ray-visible markers (18), in particular x-ray-visible sleeves, at least at the longitudinal ends. Medical device according to one of the preceding claims, characterized in that the lattice elements (11, 12, 13, 14) are sheathed with an adhesion promoter, in particular polyurethane, the adhesion promoter being the, in particular, material connection of the cover (16) to the lattice structure (10) ) forms. Medical device according to one of the preceding claims, characterized in that the lattice elements (11, 12, 13, 14) form webs which are integrally coupled to one another by web connectors (17) or wires which are interwoven with one another. Medical device according to one of the preceding claims, characterized in that the lattice structure (10) forms, at least in sections, a cylindrical and / or funnel-shaped hollow body. Medical device according to one of the preceding claims, characterized in that the medical device is arranged in a compressed state on a transport wire (19) so that the medical device is axially displaceable within a supply tube, the supply tube having an inner diameter of at most 0.7 mm, in particular a maximum of 0.52 mm, in particular a maximum of 0.42 mm. Medical device according to one of the preceding claims, characterized in that the medical device is precisely compatible with a 2Fr catheter. Method for producing a medical device for insertion into a hollow body organ according to one of the preceding claims, wherein the method comprises the following steps: a. Providing a compressible and expandable lattice structure (10) made of lattice elements (11, 12, 13, 14) which delimit closed cells (15) of the lattice structure (10); b. Coating the grid structure (10) with an adhesion promoter, in particular made of polyurethane; and c. Applying a cover (16) to the lattice structure (10) by means of an electrospinning process. Procedure according to Claim 16 , characterized in that the lattice structure (10) is coated with the adhesion promoter by a dip coating process. Procedure according to Claim 16 or 17th , characterized in that the adhesion promoter and the cover (16) each have a plastic material, in particular from the same group of materials, preferably polyurethane.

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