DE102016102503A1 - Method of making a stent and stent - Google Patents

Abstract

The invention relates to a method for producing a stent in the form of a tubular support structure comprising at least one thread and to such a stent. In this case, at least one thread is helically wound onto a winding core, wherein the at least one thread is placed over each other at intersection points crosswise, so that a tubular helically wound scrim is formed from the at least one thread on the winding core. Subsequently, in particular a selection of crossing points is added, in particular welded.

Description

Field of the invention

The invention relates to a method for producing a stent in the form of a tubular support structure comprising at least one thread and to such a stent.

Background of the invention

If there is a constriction in a lumen or vessel, a stent can be implanted at that location to keep the constriction open. Such a stent thus forms a hollow or tubular vascular support.

Thus, such stents are typically cylindrical tube-like structures that are inserted into a vessel to support and hold it open. Such stents are e.g. used in coronary vessels, but also find use e.g. in arteries, esophagus, trachea, bile duct, gastrointestinal tract or urethra. One cause of such bottleneck may be e.g. Inflammation or a tumor.

In its research, the World Health Organization (WHO) points out that cardiovascular disease is the leading cause of death in age-related diseases in the Western world. In 2004, 8.5 million people died as a result of the disease. One year later there were 152,510 deaths in Germany. In the same year, more than 230,000 stents were used. In 77% of all vascular dilations (angioplasty) in Germany, a stent is used, with an average of 1.3 stents per person. The current cost of a stent typically varies between € 300 for metal stents and € 1200 for stents with a drug coating, cf. Akmaz, BL: "Medical-technical progress in Germany", dissertation, University of the Federal Armed Forces Hamburg, publisher Hat, 2008 ,

Typically, a distinction is made in medicine between three stent structures. Accordingly, a distinction is basically made between spiral stents, tube stents and braid stents. In this regard, the contribution of Butany, J .; Carmichael, K .; Leong, SW; Collins, MJ, "Coronary artery stents: Identification and Evaluation", Journal of Clinical Pathology (2005), p. 58, pp. 795-804 , which is hereby incorporated by reference.

Spiral stents are wound from a flat rolled material and form a simple stent shape. Due to their spiral shape, they are very flexible and easily adapt to the shape of the vessel. However, such spiral stents have the disadvantage that they have a low or limited radial force and low expansion properties. The radial force is the force with which the stent is able to impart the vessel radially outwards and can therefore also be referred to as deformation resistance or radial rigidity.

Tube stents are typically made by spark erosion or laser beam welding. The stent structure is made from a semifinished product, e.g. cut out a metal tube. Due to the diversity of these two methods, these production methods are frequently used. A disadvantage of this technique, however, is the complicated post-treatment by heat treatment and electrolytic polishing to obtain a functional surface, as well as the large material loss, which is due to the manufacturing process.

The European patent EP 0 801 934 B1 describes a welded sine wave stent using a preformed sine wave wire. Neighboring wave trains are welded together in certain patterns. Disadvantageously, undesirable folding can occur with radial compression of such a structure.

Braid stents are typically divided into machine-braided and hand-braided stents, with machine-braided stents typically braided from multiple wires and hand-braided stents made from a single wire. Machine-braided stents, such as the commercially available WALLSTENT ^® Boston Scientific, Natick, MA / USA (see. Www.bostonscientific.com) are manufactured as woven endless tube and packaged in a subsequent process step to the desired length. Due to the very flexible structure, such a braided stent is suitable for curved vessel walls. A disadvantage of these machine-braided stents is that the subsequent length-tailoring produces wire ends which can be sharp-edged, since the underlying braiding tube is manufactured as an endless product by machine. Such sharp-edged wire ends can lead to injuries, tissue damage and irritation when placing the stent. Tissue damage and irritation can lead to the formation of granulation tissue (scarring). This granulation tissue can grow through the mesh of the metal stent and again lead to a stenosis (constriction of the vessel).

The European patent EP 1 755 491 B1 Boston Scientific Limited therefore describes Method for reducing stent sutures and a stent with reduced suture profiles and closed wire configuration. For this purpose, the capped wire ends are bent over at the ends of the stent and welded.

Nevertheless, such stents, which are initially mechanically braided as an endless tube, have the disadvantage that they have a limited or low radial force. Moreover, disadvantageously, upon radial compression of these stents, significant elongation may occur, e.g. Drug eluting stents (DES) can affect the drug-based coating. The same applies vice versa in the case of dilatation. Also, when loosening a weld at the wire ends again a vulnerable open wire end arise.

From the European patent EP 0 975 279 B1 is a stent with selected welded crossed threads known. In this stent, a plurality of individual wires are welded together according to a selected pattern at certain crossing points. Even with this stent, however, an undesirably large elongation can occur with radial compression. Furthermore, open wire ends may also be present at the axial ends of the stent, which may involve the risk of tissue damage. In addition, it may be necessary for pulmonary stents due to stent migration / dislocation or infections, to remove the implanted vascular support again. In this case, such stents can disintegrate if damaged in several threads, so that the removal of the doctor can be difficult and also there is a risk of tissue damage.

Hand-braided stents are manufactured manually in a complex manufacturing process. Here, the stent structure is braided by hand from a single wire. Unfortunately, the results of manual braiding of stents are poorly reproducible. Furthermore, the productivity of this manufacturing process is in need of improvement, since manual braiding requires a great deal of working time and is therefore expensive. Typically, these stents are therefore individually hand plaited in very low cost environments.

General description of the invention

The object of the invention is therefore to provide an efficient, in particular mechanized, method for producing a stent, or a stent made of a thread structure which can be produced efficiently, inexpensively and mechanistically.

A further aspect of the object is to provide a method for producing a stent or a stent from a thread structure, which is safe in use and meets high medical quality requirements, in particular good mechanical properties with respect to the radial force and radial length change Has compression or dilation.

A further aspect of the object is to provide a method for producing a stent or a stent from a thread structure which has a radial force that is well adjustable within the desired limits.

A further aspect of the object is to provide a method for producing a stent or a stent from a thread structure which, despite radial compression and / or dilatation, poses a small risk of injury to the tissue. In particular, the stent should be fault-tolerant and even in the case of a hypothetical release of a connection point, as far as possible, there should be no injury-causing open end of the wire.

The object of the invention is solved by the subject matter of the independent claims. Advantageous developments of the invention are defined in the subclaims.

A method is disclosed for producing a stent from a thread structure in the form of a tubular wound fabric with the following steps:
Providing a winding core,
helical or helical winding of at least one thread on the winding core, wherein when wound on the winding core of the at least one thread at intersections cross over one another laid over, so is not braided, so that a tubular, preferably axially limited helically wound scrim from the at least one thread the winding core arises, and
Separating or detaching the tubular helically wound web from the hub.

The stent therefore essentially consists only of one or more threads wound into a tubular support structure. Thus, a stent in the form of a tubular thread support structure is produced from the at least one thread in the form of a tubular mat which is not braided, but consists solely of the thread or helical windings deposited one above the other in a specific pattern. The filament (s) are thus deposited on at least almost all of the successive winding points, and thus on the lateral surface, which are arranged next to one another only on the filament (s) previously deposited from the outside, ie placed on it and not led underneath. That is, the thread or threads are in particular not by way of braiding alternately superimposed and guided among themselves. The suture support structure of the stent is therefore formed by a tubular scrim where the scrim is not a braid. Furthermore, the tubular clutch is wound directly in tubular form from the at least one thread.

Advantageously, such a winding method can be very well automated or mechanically carried out on a winding core. Furthermore, such a wind-up process can be performed quickly on a winding core, so that the method disclosed here is particularly efficient and inexpensive. Nevertheless, the method is variable with respect to the desired stent parameters, e.g. Thread material, radial force, winding distance, etc., and it can produce stents of high quality, safety, reproducibility and low tolerance. In particular, the method allows a locally variable force distribution. In comparison to conventional stents, the stent according to the invention offers the possibility of a "mechanical force distribution" which makes it possible to provide the stent with a locally higher radial force at the points where, for example, an increased pressure is applied to the vessel. This is particularly interesting for tracheal and esophageal stents.

• a1) Der zumindest eine Faden wird in einer ersten axialen Richtung entweder in einer linkshändigen oder einer rechtshändigen helixförmigen ersten Hin-Wicklung auf den Wickelkern aufgewickelt,
• a2) anschließend wird derselbe Faden aus dem Schritt a1) an dem zu erzeugenden ersten axialen stirnseitig offenen Stentende um eine der ersten Umlenkeinrichtungen schlingenförmig umgelenkt und
• a3) anschließend wird derselbe Faden aus den Schritten a1) und a2) in der zum Schritt a1) entgegengesetzten zweiten axialen Richtung in einer rechtshändigen bzw. linkshändigen helixförmigen ersten Rück-Wicklung mit der zum Schritt a1) entgegengesetzten Händigkeit auf den Wickelkern wieder zurück aufgewickelt und wird dabei an Kreuzungspunkten auf der helixförmigen ersten Hin-Wicklung aus demselben Faden radial von außen abgelegt.

In particular, the winding core has at least at a first axial stent end to be generated first deflection devices for the at least one thread and the at least one thread is deflected loop-shaped on at least one of the first deflection devices. For this the following steps are carried out:

• a1) the at least one thread is wound onto the winding core in a first axial direction in either a left-handed or a right-handed helical first outward winding;
• a2) Subsequently, the same thread from the step a1) at the first axial end face open stent end is looped around one of the first deflection loop and
• a3) Subsequently, the same thread from the steps a1) and a2) in the second axial direction opposite to step a1) in a right-handed or left-handed helical first return winding with the handedness opposite to step a1) wound back onto the winding core and is stored at intersections on the helical first outward turn from the same thread radially from the outside.

Thus, the same thread is helically wound on the winding core at least once and then rewound in the loop in between. The diverters may e.g. ring-like arranged around the winding core radial deflection pins for each loop to be generated.

In particular, steps a1) to a3) are carried out a plurality of times and, as a result of the multiple loop-shaped deflection of the at least one thread on the first deflection devices, a plurality of first loop-shaped deflections arise from the at least one thread between the helical outward windings and the helical rearward windings that the tubular helically wound scrim is already generated during the winding of the at least one thread by the first plurality of loop-shaped deflections between the helical outward turns and the helical return coils axially delimited with at least a first axial end face open stent end. Preferably, at least almost all the thread sections are deflected at the first axial end side open stent end such that there are substantially no open wire ends on the first axial end face open stent end - typically except for the two terminating ends of the axially wound back and forth thread. In other words, the first axial stent end open at the end is formed by the plurality of loop-shaped deflections of the at least one thread arranged in a ring around the stent axis. The plurality of loop-shaped deflections accordingly forms the annular axial or end edge of the tubular thread support structure, which in particular has the shape of a net-like cylindrical surface.

Advantageously, an axially limited stent with a first axial stent end is thus already generated when winding, which avoids already directly on the loop-shaped deflections sharp-edged wire ends (except for the two terminating ends of the axially wound back and forth thread) and thus reduces the risk of injury, without subsequent steps for bending sharp-edged wire ends are necessary. This is efficient and at the same time creates a stent of high quality and safety against tissue injury.

• a1) der zumindest eine Faden wird in einer ersten axialen Richtung entweder in einer linkshändigen oder einer rechtshändigen helixförmigen ersten Hin-Wicklung auf den Wickelkern aufgewickelt,
• a2) anschließend wird derselbe Faden aus dem Schritt a1) an dem zu erzeugenden ersten axialen stirnseitig offenen Stentende um eine der ersten Umlenkeinrichtungen schlingenförmig umgelenkt,
• a3) anschließend wird derselbe Faden aus dem Schritt a2) in der zum Schritt a1) entgegengesetzten zweiten axialen Richtung in einer rechtshändigen bzw. linkshändigen helixförmigen ersten Rück-Wicklung, aber mit der zum Schritt a1) entgegengesetzten Händigkeit, auf den Wickelkern wieder zurück aufgewickelt und wird dabei an Kreuzungspunkten auf der helixförmigen ersten Hin-Wicklung aus demselben Faden radial von außen abgelegt,
• a4) anschließend wird derselbe Faden aus dem Schritt a3) an dem zu erzeugenden zweiten axialen stirnseitig offenen Stentende um eine der zweiten Umlenkeinrichtungen schlingenförmig umgelenkt und
• b1) anschließend wird derselbe Faden aus dem Schritt a4) in der ersten axialen Richtung in einer helixförmigen zweiten Hin-Wicklung mit derselben Händigkeit wie im Schritt a1) auf den Wickelkern wieder zurück aufgewickelt und wird dabei an Kreuzungspunkten auf der helixförmigen ersten Rück-Wicklung aus demselben Faden radial von außen abgelegt.

According to a particularly preferred embodiment of the invention, the winding core at the first axial stent end to be generated, the first deflection and at the first to be generated axial stent end second axial stent end to be generated second deflection, ie axially on both sides deflection, for the at least one thread on and

• a1) the at least one thread is wound onto the winding core in a first axial direction in either a left-handed or a right-handed helical first outward winding;
• a2) Subsequently, the same thread from step a1) is looped around one of the first deflection devices at the first axial end face of the stent to be produced,
• a3) subsequently, the same thread from step a2) in the second axial direction opposite to step a1) in a right-handed or left-handed helical first return winding but with the handedness opposite to step a1) is wound back onto the winding core and is deposited at intersection points on the helical first outward turn from the same thread radially from the outside,
• a4) Subsequently, the same thread from the step a3) at the second axial end face open stent end is looped around one of the second deflection loop and
• b1) Subsequently, the same thread from step a4) in the first axial direction in a helical second outward winding with the same handedness as in step a1) is wound back onto the winding core and thereby becomes at points of intersection on the helical first return winding filed the same thread radially from the outside.

Thus, preferably at least one helical out-turn and at least one helical-back turn are formed by the same thread by looping the same thread at an axial stent end between the helical out-turn and the subsequent helical-back turn.

In simple words, the same thread is wound in the first axial direction and rewound in the opposite second axial direction.

Preferably, the steps a1) to a4) are repeated several times, so that the at least one thread in each helical reverse winding always on the previously generated helical Hin-windings of the same thread and the same thread at each helical reverse winding always on the previously generated radially outward helical turns of the same thread is deposited radially from the outside to produce the tubular helically wound scrim. As a result of the loop-shaped deflection of the at least one thread, first loop-shaped deflections emerge from the at least one thread between the helical outward windings and the helical reverse windings, and second loop-shaped deflections result from the loop-shaped deflection of the at least one thread at the second deflection devices from the at least one thread between the helical reverse windings and the helical forward windings, so that the tubular helically wound scrim already has, during the winding of the at least one thread through the first and second loop-shaped deflections between the helical outward windings and the helical back windings. Windings, or between the helical back windings and the helical Hin windings, axially limited on both sides with a first and second axial end face open stent end is generated.

In other words, the same thread is wound on the winding core at least once, again wrapped back and wound again, but preferably several times wound alternately and repeatedly rewound and deflected on both sides between the forward windings and the back windings. In this case, the thread of all out-windings and back windings is always stored radially on the previously deposited windings from the outside, i. the thread is not intertwined in particular.

Advantageously, it is thus already possible to produce a single prefabricated stent which is axially delimited on both sides by the loop-shaped deflections already during the, preferably automated, winding, which synergistically combines efficiency, cost, quality and injury safety in a synergistic manner.

In other words, the tubular helically wound scrim is bounded axially at least on one side, preferably on both sides, by loop-shaped deflections between the helical outward turns and the helical backward turns or between the helical backward turns and the helical outward turns of the at least one thread ,

In this case, preferably at least two helical forward windings and at least one directly intermediate helical reverse winding, or vice versa, are formed by the same thread, by the same thread at both axial stent ends between the two helical outward windings and the directly intermediate helical back -Wicklung, or vice versa, axially deflected loop-shaped on both sides.

The at least one thread is thus helically or helically wound with biaxially on the winding core, wherein when wound on the winding core of the at least one thread at intersections cross over one another and not braided, so that a tubular axial limited helix-shaped scrim from which at least one thread is formed on the winding core.

In particular, the same thread is helically wound back and forth several times between the two stent ends with alternately opposite handedness. This results in a biaxial, two-layered helix-shaped tubular double-sided, circular clutches.

Preferably, therefore, the same thread is used for at least one, preferably for at least some, preferably even substantially all helical forward windings and helical reverse windings.

In this case, the same thread crosses over at least some, preferably substantially at all crossing points themselves.

In other words, the same thread is wound alternately in helical outward turns of handedness and helical backwinds in the opposite direction and with opposite handedness, laying the same thread winding by turn on the winding core, with each helical back winding spaced parallel is deposited to the previously deposited helical reverse windings and across the previously deposited helical forward windings and wherein each helical forward winding is deposited parallel spaced from the previously deposited helical forward windings and across the previously deposited helical back windings.

The stent thus produced is therefore preferably a filament stent, in particular a filament stent consisting of a single thread, which is often wound back and forth in both axial directions and deposited radially from the outside at each helical winding superimposed on the axis of the winding core becomes. But it is also possible to use several threads, which are wound back and forth.

A stent consisting of only one thread has the advantage that, even if the stent is damaged, it does not break down into several threads. Thus, the removal is easier for the doctor because the doctor only has to pull on a thread and also the risk of tissue damage is lower.

Preferably, the at least one thread superimposed upon winding on at least some of the crossing points, in particular with itself added, in particular cohesively connected to increase the radial force of the tubular helically wound Geleges.

Particularly preferably, the at least one thread superimposed upon winding on at least some of the crossing points, in particular joined with itself, in particular materially joined, e.g. welded, soldered or glued. Alternatively, positive or frictional connections or combinations thereof, e.g. Crimping, possible.

The bonding or welding is preferably carried out before the separation or removal of the Geleges of the winding core on the winding core. In other words, the scrim is wound on the same winding core and - possibly after a step of thermofixing the wound thread structure - connected or welded at the crossing points, which makes the manufacturing process simple and efficient.

In particular, electron beam welding, laser beam welding, resistance welding, friction welding or micro plasma welding come into consideration for welding the intersection points. The beam welding method, laser and electron beam welding are used in particular because of their high spatial resolution by focusing on a few micrometers, the low heat input and high flexibility.

In the case of polymer-based stents, laser welding as well as ultrasonic welding, heating element welding, etc. come into consideration. In particular, thermoplastic materials can be welded. As an alternative joining technology, here the adhesive technology offers

Although the at least one superimposed thread is preferably connected or welded at a plurality of, but not at all intersection points in order to adjust the mechanical properties of the tubular wound loop as a whole.

Preferably, the proportion of the connected or welded crossing points in the total number of crossing points in the range between 2.5% and 40%, preferably between 5% and 25%. In these areas, in combination with the unbroken tubular scrim, the desired radial force can be adjusted and the elongation of the tubular scrim with radial compression can be kept within the desired limits. It is particularly advantageous that the radial force can be locally varied via the stent, e.g. through appropriately targeted spot weld patterns. In particular, areas with a higher proportion of fixed crossing points and areas with a small number of crossing points can be provided. In this case, an oriented installation may be necessary.

Further preferably, the at least one thread is deposited at the crossing points at a crossing angle in the range of 10 ° to 80 °, preferably in the range of 30 ° to 60 ° above one another. In other words, the helical out-turns and the helical-back windings intersect at an angle in these regions, so that diamond-shaped openings respectively arise between two adjacent helical outward windings and two adjacent helical backward windings transverse thereto, creating a network structure is formed. The network structure of the lateral surface is therefore diamond-shaped. Since the at least one thread or the helical windings is not intertwined, either the two or more directly adjacent helical forward windings are deposited at the most crossing points over the two or more directly adjacent helical return windings running transversely thereto or vice versa , ie they do not run predominately one above the other and with each other.

Preferably, the tubular helix-wrapped scrim is heat-set on the winding core before the at least one superimposed upon winding filament at at least some of the crossing points is welded and / or before the tubular helically wound scrim is separated or removed from the winding core. By thermofixing before joining or before welding the round-Geleges on the winding core, the clutch better retains its tubular shape. It receives a kind of "memory" for the scrim-form on the winding core, whereby the risk of slippage of the at least one thread at the crossing points can be reduced, so that a precise position of the windings is ensured even after the connection or welding.

Preferably, the at least one thread is held under helical winding by means of a biasing device under a defined bias, so that the at least one thread is stored in the helical winding with a defined bias on the previously stored helical windings of opposite handedness.

According to a preferred embodiment of the invention, the winding core has a radial tensioning device, by means of which the finished tubular helix-shaped scrim is radially tensioned on the winding core.

This has the advantage that the scrim is e.g. can be tightened after heat setting and / or before joining or welding, which can have a positive effect on the precision or the reproducibility.

The subject of the invention is also the stent. The stent accordingly comprises a tubular helix-shaped, in particular biaxially wound, round at least one thread, or consists of the round layer, the at least one thread being laid one above the other at points of intersection. The at least one thread or the helical windings are not intertwined, so it is not a braid.

Preferably, the at least one thread is wound in left-handed and right-handed helical windings, which intersect at the crossing points, wherein the helical windings are deposited at the crossing points respectively over the entire underlying helical windings of each opposite handedness and are not intertwined with these particular.

Accordingly, that portion of the at least one thread of all helical windings along the thread is preferably located on at least almost all of the successive intersection points of this helical winding over the at least one thread of the underlying helical windings of opposite handedness, each of them helical winding in its entirety lies completely radially over the entirety of the helical windings of the opposite handedness lying next to each other radially below it.

Preferably, the tubular helically wound scrim is axially delimited with at least a first axial end face open stent end, wherein
the at least one thread is wound in a first axial direction in either a left-handed or a right-handed helical first out-turn,
the same thread is loop-shaped at the front-side jacket edge of the tubular helically wound loop at the first axial end-side open stent end, and
the same thread is wound in the second axial direction opposite to the helical first outward winding in a right-handed or left-handed helical first return winding, ie with the handedness opposite to the helical first outward winding, and at intersection points on the helical first outward winding is stored from the same thread.

Preferably, the tubular helically wound scrim is axially bounded on both sides with a first and second axial stent end open at the end, wherein the same thread helically wound, preferably several times, in the first axial direction and helically wound back in the opposite second axial direction and helix the same thread is looped at the first and second axial end-side open stent ends between the respective helical outward turns and helical backward turns.

Thus, the stent, which is axially delimited on both sides, is formed, which is bounded by the loop-shaped deflections at the axial ends of the stent which are open at the end, which ensures a high level of protection against injury and radial expansion force.

In particular, therefore, the tubular helically wound scrim is axially bounded on both sides with at least a first and a second axial end face open stent end, wherein
the at least one thread is wound in a first axial direction in either a left-handed or a right-handed helical first out-turn,
the same thread is loop-shaped at the front-side jacket edge of the tubular helically wound loop at the first axial end-side open stent end,
the same thread is wound in the second axial direction opposite to the helical first outward turn in a left-handed helical first reverse winding having handedness opposite to the helical first outward turn, and at intersections on the helical first outward turn thereof Thread deposited radially from the outside - that is not intertwined - is,
the same thread is looped at the second axial end face open stent end and
the same filament is wound in the first axial direction in a helical second outward winding having the same handedness as the helical first outward winding and parallel to and adjacent to the helical first outward winding, and at points of intersection on the helical first return winding the same thread stored radially from the outside - that is not intertwined - is.

According to a preferred embodiment of the invention, the same thread is helically wound several times helically in the first axial direction, looped in the second axial direction at the first axial end side open stent, helically wound with opposite handedness in the second axial direction and turn again at the second axial end side open stent end in the first axial direction looped, wherein the same thread stored at each helical reverse winding on the previously generated helical Hin-windings of the same thread - that is not intertwined - and the same thread at each helical reverse winding on the previously generated helical Hin- Windings of the same thread stored - that is not intertwined - is, wherein the loop-shaped deflections between the helical Hin-windings and the helical return windings, the first and second axial end-side open stent ends form.

In other words, the helical forward windings are wound side by side, winding by winding, and the helical rear windings are laid parallel to each other across the windings winding-by-winding and i) the respective helical back windings are alternately on the underlying helically shaped outward windings and ii) the respective helical outward winding deposited on the underlying helical reverse windings.

In other words, a plurality of helical forward windings and rear windings are included, with the helical forward windings and the helical rear windings alternately superimposed - that is not intertwined - are.

Preferably, therefore, the same thread is wound back and forth many times and each helical winding is deposited at the crossing points on the underlying helical windings of opposite handedness.

In this case, a left-handed helical winding on a right-handed helical winding and then a right-handed helical winding on a left-handed helical winding etc. are preferably always alternately deposited.

According to a preferred embodiment of the invention, the at least one superposed thread is connected to at least some of the points of intersection, in particular with itself.

Preferably, the at least one superimposed thread at least some of the crossing points, in particular with itself, welded.

In particular, the at least one superimposed thread at several, but not at all crossing points, in particular with itself, connected or welded.

Preferably, the crossing points are connected or welded at regular intervals, e.g. every second, third, fourth or nth of the crossing points relative to the circumference and / or the central longitudinal axis of the particular cylindrical shape of the tubular helically wound loop.

To set the desired radial force of the tubular wound Geleges it has as proven advantageous when the proportion of the connected or welded crossing points in the total number of crossing points in the range between 2.5% and 40%, preferably between 5% and 25%.

Preferably, the crossing angle of the at least one superposed thread at the crossing points in the range between 10 and 80 °, preferably in the range between 30 ° and 60 °.

According to a preferred embodiment of the invention, the tubular helix-wrapped scrim is heat-set.

A pulmonary stent is exposed to cyclic dilatations at the rate of respiratory rate and is compressed about 1-2 mm in diameter with a starting diameter of 8-12 mm. Upon coughing, significantly larger diameter reductions may occur, e.g. a Nitinol stent and a silicone coating can partially go along. Further areas of application for larger stents with similar requirements as in the trachea (neutral environment, pH ~ 7) are the esophagus, gall bladder and the gastrointestinal tract (pH up to 1). However, use for coronary stents is also possible.

The stent which can be produced according to the invention can therefore in particular comprise a blood vessel stent, e.g. a cardiac or coronary artery stent or stent, or pulmonary, tracheal, laryngeal, ureteral, gastrointestinal, or bile duct stents. Depending on the application different threads come into consideration.

Thus, the thread of a nickel-titanium alloy, of nitinol, of magnesium, of a magnesium alloy, of a medical grade stainless steel, a cobalt alloy, a chromium alloy, a cobalt-chromium alloy, from a niobium alloy, a tantalum alloy, a platinum alloy, a platinum-chromium alloy or a polymer. In the case of a metal thread, it is also possible to speak of a wire so that the stent consists of a tubular wire support structure.

Depending on the application, the at least one thread has a diameter in the range from 1 .mu.m to 400 .mu.m, preferably in the case of a blood vessel stent in the range between 10 .mu.m and 150 .mu.m, and preferably in the case of a pulmonary, tracheal, laryngeal, ureteral, gastrointestinal - or bile duct stents in the range between 10 .mu.m and 300 .mu.m, on.

Preferably, the at least one thread, or the helical windings of the tubular helical wound gel are at a distance in the range of 0.5 mm to 5 mm, preferably in the case of a blood vessel stent in the range between 0.5 mm and 2 mm and preferably in the case of a pulmonary, tracheal, laryngeal, ureteral, gastrointestinal or bile duct stent in the range between 3 mm and 5 mm.

Depending on the application and the thread, the tubular wound scrim can each be in the range between 3 and 150 helical windings, preferably in the range between 12 and 60 helical windings in both axial directions, i. of both hands.

Depending on the application, the diameter of the tubular helical wound gel is in the range between 0.1 mm and 25 mm, preferably in the case of a blood vessel stent in the range between 0.1 mm and 10 mm, and preferably in the case of a pulmonary, tracheal, laryngeal, ureteral, gastrointestinal or bile duct stents ranging between 5 mm and 25 mm.

In summary, the tubular helically wound scrim is in particular a monofilament, unwound and unblochten, biaxial, bilayer and / or by deflections of the, in particular a single, thread axially bounded on both sides, tubular helical wound round clutch.

In the following the invention will be explained in more detail by means of embodiments and with reference to the figures, wherein the same and similar elements are partially provided with the same reference numerals and the features of possibly different embodiments can be combined.

Brief description of the figures

Show it:

1 a perspective view of a winding core,

2 a radial side view of the front of the winding core 1 with partially wound wire,

3 a radial side view of the back of the winding core 2 .

4 a radial side view of the winding core 2 with completely wrapped thread, forming the round-clutch,

5 a schematic view of the symbolically cut and unrolled lateral surface of the winding core to illustrate the thread tray,

6 a schematic representation of the round-Geleges on the winding core and a heat-setting unit,

7 a schematic representation of a section of the Geleges with some welds,

8th a photographic representation of an example wound on a winding core round-gel,

9 a scanning electron micrograph of a welded crossing point of a Nitinol wire of the round-off 8th ,

Detailed description of the invention

Referring to 1 becomes a cylindrical winding core 12 with a lateral surface 12c and two with respect to the central axis of symmetry A axial end faces 12a . 12b used. The winding core 12 is on both sides by a wave 14 continued. Near the two ends 12a . 12b extend out of the lateral surface 12c Radial deflection in the form of upper and lower deflecting pins USa, USb. The upper and lower deflecting pins USa, USb are ring-shaped near both ends of the winding core 12 around the circumference of the lateral surface 12c arranged.

Referring to the 2 - 5 becomes a single thread in this example 22 , in particular a metal wire, in this example in the form of a Nitinol wire with a wire diameter of 200 microns at an initial attachment means in the form of a fastening pin 24 attached. Subsequently, the winding core 12 by means of the shaft 14 continuously in one and the same direction R (cf. 1 ) rotates. During the rotation of the winding core 12 becomes the thread 22 axially back and forth, ie in this example moved up and down to wind it in evenly alternating opposite helical windings. For this example, a converted rewinding machine can be used.

The string 22 is first of the initial fastener 24 passed by an upper deflecting pin US1a.

The string 22 is then in a first axial direction A1, in this example axially downwards in a first outward turn HW1 helically on the winding core 12 wound up with a first handedness until the first outward winding HW1 is deflected around a lower deflection pin US1b. This forms the thread 22 a lower loop-shaped deflection SU1b.

Subsequently, under further rotation of the same direction R of the winding core 12 the axial feed direction of the thread 22 vice versa so as to wind back axially a first return coil RW1 helically in the opposite axial direction A2 and with opposite second handedness.

The first reverse winding RW1 is at the back ( 3 ) at a crossing point HW1RW1 with respect to the axis of rotation A radially from the outside over the thread 22 the first outward winding HW1 filed so that at this point the first return winding RW1 comes to lie radially outside the first outward winding HW1.

The first reverse winding RW1 is again front side ( 2 ) at a further crossing point HW1RW1 with respect to the axis of rotation A radially from the outside over the thread 22 the first outward winding HW1 filed so that at this point the first return winding RW1 again comes to lie radially outside the first outward winding HW1.

Subsequently, the thread 22 is deflected about an upper deflecting pin US2a adjacent to the upper deflecting pin US1a and thereby forms an upper loop-shaped deflecting SU2a.

With another reversal of the axial feed direction of the thread 22 this is then again in the first axial direction A1, ie axially downward in a second outward winding HW2 helical on the winding core 12 wound up again with the first handedness.

The second turn HW2 is reversed ( 3 ) and front ( 2 ) are deposited on the rear and front crossing point RW1HW2 radially from outside on the first reverse winding RW1.

Subsequently, the second outward winding HW2 is deflected by a lower deflecting pin US2b. This forms the thread 22 another lower loop-shaped deflection SU2b.

Subsequently, under further rotation of the same direction R of the winding core 12 the axial feed direction of the thread 22 vice versa so as to wind back axially a second reverse winding RW2 helically in the opposite axial direction A2 and with the opposite second handedness.

The second reverse winding RW2 is at the back ( 3 ) at intersections HW1RW2, HW2RW2 with respect to the axis of rotation A radially from the outside over the thread 22 the first and second out-winding HW1, HW2 stored so that at these points, the second reverse winding RW2 comes to lie radially outside the first and second out-winding HW1, HW2.

The second reverse winding RW2 is again front side ( 2 ) at further crossing points HW1RW2, HW2RW2 with respect to the axis of rotation A radially from the outside over the thread 22 the first and second outward winding HW1, HW2 stored, so that at these locations, the second reverse winding RW2 again comes to lie radially outside the first and second outward winding HW1, HW2.

Subsequently, the thread 22 is deflected about an upper deflecting pin US3a adjacent to the upper deflecting pin US2a, thereby forming an upper loop-shaped deflecting SU3a.

By reversing the axial feed direction of the thread 22 this is then again in the first axial direction A1, ie axially downward in a third outward turn HW3 helical on the winding core 12 wound up again with the first handedness.

The third outward winding HW3 is in each case at the back ( 3 ) and front ( 2 ) are deposited on the rear and front crossing points RW1HW3, RW2HW3 radially from the outside on the first and second reverse windings RW1, RW2.

Subsequently, the third outward winding HW3 is deflected by a lower deflecting pin US3b. This forms the thread 22 another lower loop-shaped deflection SU3b.

Subsequently, under further rotation of the same direction R of the winding core 12 the axial feed direction of the thread 22 vice versa so as to wind back axially a third return winding RW3 helically in the opposite axial direction A2 and with the opposite second handedness.

The third reverse winding RW3 is at the back ( 3 ) at points of intersection HW1RW3, HW2RW3, HW3RW3 with respect to the axis of rotation A radially from the outside over the thread 22 the first, second and third out-winding HW1, HW2, HW3 filed so that at these points, the third reverse winding RW3 comes to lie radially outside the first, second and third outward winding HW1, HW2, HW3.

The third reverse winding RW3 is again front side ( 2 ) at further crossing points HW1RW3, HW2RW3, HW3RW3 with respect to the axis of rotation A radially from the outside over the thread 22 the first, second and third outward winding HW1, HW2, HW3 stored, so that at these points, the third reverse winding RW3 again comes to lie radially outside the first, second and third outward winding HW1, HW2, HW3.

Subsequently, the thread 22 is deflected about an upper deflecting pin US4a adjacent to the upper deflecting pin US3a and forms an upper loop-shaped deflecting SU4a.

This reciprocal winding of the thread 22 will continue until the wire 22 around all upper and lower deflecting pins USa and USb was deflected, with the complete tubular helically wound biaxial double-layered round clutch 30 which is formed in 4 is shown. The upper and lower loop-shaped deflections SUa, SUb form the upper or lower open stent end 34a . 34b or the respective axial edge of the jacket of the round-Geleges 30 ,

The filing pattern of the front side ( 2 . 4 . 5 ) and back ( 3 . 5 ) reveals that the tubular support structure thus produced is a scrim and not a braid.

It can be seen that the totality of the deflection pins short with USa, USb, the entirety of the loop-shaped deflections short with SUa, SUb, the entirety of the forward windings short with HW, the entirety of the back windings short with RW and the entirety of the crossing points from back and forth windings or vice versa short with HWRW, RWHW or 31 . 32 referred to as.

In this example, it is one of a single thread 22 made, thus single-thread, tubular helical wound round clutch 30 in which each winding HW, RW is rotated about 360 ° about the winding core 12 is wound, so that the respective upper and lower loop-shaped deflection SUa, SUb, which limits each winding HW, RW on both sides, are located approximately at the same angular position (shifted by the respective angular feed of winding to winding). However, it is also possible, each winding only by a smaller angle of rotation, for example about 180 °, to the winding core 12 to wind or to wind a larger angle of rotation, for example two revolutions, ie about 720 °, or more or less. The filing at the intersection points thus generated results accordingly.

With the selection of the winding parameters, eg the rotation angle, the desired properties of the finally produced tubular helix-shaped wound round layer can be influenced, in order to be able to adapt this, for example, to the desired application.

5 shows again the sequence of the first and second return windings and first and second back windings in a schematically unrolled representation.

Referring to 6 becomes the finished tubular helix-wound round clutch 30 in a heat-setting unit 40 heat-set at about 350 ° to 650 ° for about 2 to 15 minutes to the tension of the still unwelded Rund-Geleges 30 to influence. As a result, during the subsequent welding of the crossing points, it is possible to prevent the wire from being welded at the points of intersection to be welded 32 slips, which contributes to a higher precision.

The winding core 12 also has a radial clamping device 44 on, in this example, such that the winding core 12 from two halves 12a . 12b exists, which can be pressed apart, in particular after the winding and / or after thermosetting, to that on the winding core 12 wound round clutch 30 up slack.

Referring to 7 when the tubular helix-wrapped round clutch 30 finished, selected crossing points 32 joined together, welded in this example. In this example, there are eight welded crossing points 32 which are selected according to a predetermined pattern, in the present example from left to right as a 2-0-4-0-2 sequence. By means of the number and positioning of the welded crossing points 32 For example, the mechanical properties, eg the radial force, flexibility and / or flexibility, can be set to the desired requirements. The stent 34 is therefore due to the fully wound round clutch 30 educated.

Thus, although a plurality or plurality of crossing points are welded, but not all. There are therefore both unwelded crossing points 31 as well as welded crossing points 32 , In particular, as many as necessary, but as few as possible crossing points are welded together. This will be a stent 34 from the tubular completely helix-wound round clutch 30 made, which has a good radial force but is still not excessively stiff, but flexible. A stent made in this way 34 is in particular compactable and is adaptable to the vessel geometry.

Furthermore, still the two terminating ends of the thread 22 on the clutch 30 attached, eg welded.

Referring to 8th is a prototype of the tubular helix-shaped wound loop 30 from a Nitinol wire with a wire diameter of 200 microns and a diameter of the round-Geleges 30 represented by about 1.5 cm. In this example, the crossing angle at the crossing points is about 60 °.

It was on a winding core 12 for the manual production of a braided filament stent 34 was designed, used. Then the windings were made. It has been shown that with the deflecting pins USa, USb a defined storage location for the thread or wire 22 on the winding core 12 is given, which is advantageous in order to avoid slippage. Furthermore, the thread or wire 22 filed with a defined bias to at the intersection points to be welded 32 a mechanical contact of the crossing thread or wire 22 sure. In addition, by the bias of the thread or wire 22 slipping on the hub 12 counteracted.

As schematically in 5 is shown, the wire is 22 through a clamping device 42 , For example, comprising a spring when winding on the winding core 12 held under a defined bias.

For guiding the thread or wire 22 Along the winding core structure is a precise deflection at the deflecting pins USa, USb of the two stent ends 34a . 34b guaranteed.

Welding investigations have shown that a crossed nitinol wire with a diameter of Ø = 200 μm can be joined by means of micro-electron beam welding technology and that a sufficiently high bond strength can be achieved. The connection can be at the crossing point 32 of the Crossing Nitinol Wire 22 be adjusted by parameters such as beam positioning, focus diameter, wire bias, etc.

Referring to 9 is a welded crossing point 32 represented, which was accordingly welded by means of electron beam technology. Here, a beam current of 0.13 mA, an acceleration voltage of 60 kV, a focus diameter of about 50-100 microns and a pulse duration of 400 ms to 500 ms was used. The electron beam is preferably not perpendicular in the radial direction, but obliquely, so with an axial direction component to the welding crossing points 32 directed to melt the interface between the superimposed wire sections precisely and weld. The thread sections are welded directly to each other, ie there is no welding filler ( DIN 1910-100: 2008-02 ) used.

The present example in 8th . 9 shows a prototype of a self-dilating tracheal stent. However, it is also possible to produce balloon-dilating cardiac stents or other stents if the process parameters are adapted accordingly. To adapt to the particular application of the stent 34 one or more of the following parameters will be adjusted accordingly:
Material of the thread 22 .
Diameter of the thread 22 .
Angle of rotation of the windings HW, RW between the deflection devices USa, USb,
Diameter of the winding core 12 .
Number of welded crossing points 32 .
Number of unwelded crossing points 31 .
Arrangement and / or ratio of the number of welded and unwelded crossing points 32 . 31 , and / or crossing angle of the thread at the crossing points 32 . 31 ,

Depending on the material and diameter of the thread, the joining method and the process parameters of the respective joining method, for example, in electron beam welding, the beam current, focus diameter, etc., can be adjusted. For example, by means of laser beam welding in particular, non-conductive threads, for example made of plastic can be welded. From today's perspective, the complexity of the braiding process makes it difficult to automate the manual process of making a hand-braided stent. However, the present invention can produce a similar suture support structure as a hand-braided stent, ie, in particular, a suture stent 34 in which the one single (or possibly also some threads) on both axial stent ends 34a . 34b looped, but in contrast to the hand-braided stent, the thread or the helical windings are not braided, but is successively deposited on each other by winding or are. In other words, due to the winding process, a different thread guide course is selected without the handweaving alternating over and underpassing of the wire or thread. In order nevertheless to achieve the desired stability, this is achieved, in particular, with defined intersecting points of intersection, in particular welding points at selected points of intersection 32 supported. This may approximate the structure of the hand-braided stent and still allow a mechanized or automated process. The disadvantages of the hand-braided stent, ie high working time and poor reproducibility are eliminated. The result is a stent structure that can run automatically at least in the two sections of the process of winding and welding. It is not necessary to remove the tubular biaxially helically wound scrim from the hub before the welding process is completed. It can therefore be on the same core 12 be wound and welded. It is advantageous if the core 12 easy and quick to install in the technical joining system.

The stent produced by the present invention 34 is a medical implant or an endoprosthesis, in which or which in particular a single thread or wire 22 helically around a cylindrical winding core 12 with the help of deflection pins USa, USb is wound. By the deflection pins USa, USb at the axial ends of the cylindrical winding core 12 can the thread or wire 22 be diverted and stretched. Winding parameters, such as the thread or wire distance can be adjusted. Because the thread or wire 22 are not interlaced and interlaced, but only repeatedly wrapped or stored, are according to a selected pattern according to connecting or welding points at the intersections 32 produced. The connection or welding points are selected in particular in such a way that a homogeneous cohesion of the implant is ensured, the required radial rigidity is achieved and at the same time a sufficiently high axial bending is made possible. In the case of a single-thread stent, only the two ends of the thread are to be closed, which is likewise done with the abovementioned joining or welding methods in one work step with the welding of the selected points of intersection 32 can be done.

By the invention disclosed herein, the hand braiding of finished preconfigured stents can be replaced by an automated winding and welding process and thus the time required can be significantly reduced. In addition, due to the reduction of manual work, a significant cost reduction can be expected. Furthermore, this type of production further automates the process and ensures reproducibility. Production in environments with higher wage structure may be possible.

It will be apparent to those skilled in the art that the above-described embodiments are to be read by way of example, and that the invention is not limited to them, but that they can be varied in many ways without departing from the scope of the claims. It can also be seen that the characteristics, irrespective of whether they are in the Also when individually described together with other features, and features disclosed in connection with the method of manufacture are also deemed to be disclosed to the manufactured stent, and also to features that are disclosed in the claims, figures or otherwise vice versa.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• EP 0801934 B1 [0008]
• EP 1755491 B1 [0010]
• EP 0975279 B1 [0012]

Cited non-patent literature

• Akmaz, BL: "Medical-technical progress in Germany", dissertation, University of the Federal Armed Forces Hamburg, publisher Hat, 2008 [0004]
• Butany, J .; Carmichael, K .; Leong, SW; Collins, MJ, "Coronary Artery Stents: Identification and Evaluation," Journal of Clinical Pathology (2005), p. 58, pp. 795-804. [0005]
• DIN 1910-100: 2008-02 [0129]

Claims (31)

Method for producing a stent ( 34 ) comprising the following steps: providing a winding core ( 12 ), helical winding of at least one thread ( 22 ) on the winding core ( 12 ), wherein when winding on the winding core ( 12 ) the at least one thread at crossing points ( 31 . 32 ) is placed over each other on a cross, so that a tubular helix-wound scrim ( 30 ) from the at least one thread ( 22 ) is formed on the winding core, separating the tubular helically wound Geleges ( 30 ) from the winding core ( 12 ). Method according to claim 1, wherein the winding core ( 12 ) at least at a first axial stent end ( 34b ) first deflection devices (USb) for the at least one thread ( 22 ) and a1) the at least one thread ( 22 ) in a first axial direction (A1) in either a left-handed or a right-handed helical first out-turn (HW1) on the winding core ( 12 ) a2) then the same thread ( 22 ) from the step a1) at the first axial end face open stent end around one of the first deflection devices (USb) is looped around a loop and a3) then the same thread ( 22 ) from step a2) in the second axial direction (A2) opposite to step a1) in a helical first return winding (RW1) with the handedness opposite to step a1) on the winding core ( 12 ) and at intersections ( 31 . 32 ) on the helical first out winding (HW1) from the same thread ( 22 ) is stored. Method according to claim 2, wherein the steps a1) to a3) are carried out a plurality of times and by the loop-shaped deflection of the at least one thread ( 22 ) at the first deflection devices (USb) first loop-shaped deflections (SUb) from the at least one thread ( 22 ) arise between the helical outward turns (HW) and the helical backward turns (RW), so that the tubular helix-shaped loop (FIG. 30 ) already during winding of the at least one thread ( 22 ) is generated by the first loop-shaped deflections (SUb) between the helical outward turns (HW) and the helical backward turns (RW) axially delimited with at least one first axial end face open stent end. Method according to one of the preceding claims, wherein the winding core ( 12 ) at a first axial stent end ( 34b ) first deflecting means (USb) and at the second axial stent end to be produced opposite the first axial stent end to be produced (US Pat. 34a ) second deflection means (USa) for the at least one thread (US 22 ) and a1) the at least one thread ( 22 ) in a first axial direction (A1) in either a left-handed or a right-handed helical first out-turn (HW1) on the winding core ( 12 ) a2) then the same thread ( 22 ) from the step a1) at the first axial end-side open stent end ( 34b a) subsequently the same thread from step a2) in the second axial direction (A2), which is opposite to step a1), in a helical first return winding (RW1) to the step a1) opposite handedness, on the winding core ( 12 ) and at intersections ( 31 . 32 ) is deposited on the helical first out winding (HW1) from the same thread, a4) subsequently the same thread ( 22 ) from the step a3) at the second axial end-side open stent end ( 34a ) is looped around one of the second deflection devices (USa) and b1) subsequently the same thread ( 22 ) from step a4) in the first axial direction (A1) in a helical second outward winding (HW2) having the same handedness as in step a1) on the winding core ( 12 ) and at intersections ( 31 . 32 ) on the helical first return winding (RW1) from the same thread ( 22 ) is stored. Method according to claim 4, wherein the steps a1) to a4) are carried out a plurality of times in succession, the at least one thread ( 22 ) at each helical reverse winding (RW) on the previously generated helical outward turns (HW) of the same thread ( 22 ) and the same thread is deposited at each helical backwinding (RW) on the previously generated helical outward turns (HW) of the same thread to form the tubular helically wound scrim (FIG. 30 ) and wherein by the loop-shaped deflection of the at least one thread on the first deflection means (USa) first loop-shaped deflections (SUa) from the at least one thread ( 22 ) between the helical outward turns (HW) and the helical backward turns (RW) and by the loop-shaped deflection of the at least one thread ( 22 ) at the second deflection devices (USb) second loop-shaped deflections (SUb) from the at least one thread ( 22 ) arise between the helical back windings (RW) and the helical out windings (HW), making the tubular helical wrapped scrim ( 30 ) already during winding of the at least one thread ( 22 ) through the first and second loop-shaped deflections (SUb, SUa) between the helical outward turns (HW) and the helical backward turns (RW), or between the back helical turns (RW) and the helical outward turns ( HW), axially limited on both sides with a first and second axial end face open stent end is generated. Method according to one of the preceding claims, comprising the following step: joining of the at least one thread deposited on one another during winding ( 22 ) at least at some of the crossing points ( 32 ). Method according to one of the preceding claims, comprising the following step: cohesive joining, in particular welding, soldering or gluing the at least one superimposed upon winding filament ( 22 ) at least at some of the crossing points ( 32 ).  The method of claim 7, wherein the welding of the crossing points by means of electron beam welding, laser welding, resistance welding, friction welding or micro-plasma welding is performed. Method according to one of the preceding claims, wherein the at least one superimposed thread ( 22 ) at several, but not at all crossing points connected or welded. Method according to one of the preceding claims, wherein the proportion of connected or welded crossing points ( 32 ) in the total number of crossing points ( 31 . 32 ) ranges between 2.5% and 40%, preferably between 5% and 25%. Method according to one of the preceding claims, wherein the at least one thread at the crossing points ( 31 . 32 ) is deposited one above the other at a crossing angle in the range of 10 ° to 80 °, preferably in the range of 30 ° to 60 °. A method according to any one of the preceding claims, wherein the tubular helix-wrapped scrim ( 30 ) on the winding core ( 12 ) in a heat-setting unit ( 40 ) is heat-set before the at least one superimposed thread ( 22 ) at least at some of the crossing points ( 32 ) and / or before the tubular helix-wrapped scrim ( 30 ) from the winding core ( 12 ) is separated. Method according to one of the preceding claims, wherein the at least one thread ( 22 ) in the helical winding by means of a biasing device ( 42 ) is held under a defined bias, so that the at least one thread is deposited in the helical winding with the defined bias on the previously stored helical windings (HW, RW) opposite handedness. Method according to one of the preceding claims, wherein the winding core ( 12 ) has a radial clamping device, by means of which the finished tubular helically wound scrim is radially tensioned on the winding core. Stent ( 34 ), in particular producible according to one of the preceding claims, comprising a tubular helix wound helically from at least one thread ( 30 ), wherein the at least one thread ( 22 ) at crossing points ( 31 . 32 ) is stored one above the other. Stent ( 34 ) according to claim 15, wherein the tubular helically wound scrim ( 30 ) axially delimited with at least a first axial end face open stent end ( 34b ), wherein the at least one thread ( 22 ) is wound in a first axial direction (A1) in either a left-handed or a right-handed helical first out-turn (HW1), the same thread ( 22 ) at the first axial end side open stent end ( 34b ) is looped in the form of a loop and the same thread is wound in the second axial direction (A2) opposite the helical first outward winding (HW1) in a helical first backwinding (RW1) with the handedness opposite to the helical first outward winding (HW1) and at crossing points ( 31 . 32 ) on the helical first out winding (HW1) from the same thread ( 22 ) is stored. Stent ( 34 ) according to one of claims 15 or 16, wherein the tubular helically wound scrim ( 30 ) axially bounded on both sides with a first and second axial frontally open stent end ( 34a . 34b ), the same thread ( 22 ) helically wound in the first axial direction (A1) and helically wound back in the opposite second axial direction (A2) and the same thread ( 22 ) at the first and second axial end faces open stent end ( 34b . 34a ) is looped between the respective helical forward windings (HW) and helical rear windings (RW). Stent ( 34 ) according to any one of claims 15 to 17, wherein the tubular helically wound scrim ( 30 ) axially delimited on both sides with at least a first and a second axial stent end open at the end ( 34b . 34a ), wherein the at least one thread ( 22 ) is wound in a first axial direction in either a left-handed or a right-handed helical first-turn (HW1), the same thread (FIG. 22 ) at the first axial end side open stent end ( 34b ) is looped, the same thread ( 22 ) is wound in the second axial direction (A2) opposite the helical first outward winding (HW1) in a helical first reverse winding (RW1) with the handedness opposite to the helical first outward winding (HW1), and at intersection points ( 31 . 32 ) on the helical first out winding (HW1) from the same thread ( 22 ) is stored the same thread ( 22 ) at the second axial end side open stent end ( 34a ) is looped and the same thread ( 22 ) is wound in the first axial direction (A1) in a helical second outward winding (HW2) having the same handedness as the helical first outward winding (HW1) and at intersection points (H) 31 . 32 ) on the helical first return winding (RW1) from the same thread ( 22 ) is stored. Stent ( 34 ) according to claim 18, wherein the same thread ( 22 ) helically wound several times in the first axial direction (A1), at the first axial end side open stent end ( 34b ) is looped in the second axial direction (A2), wound back helically in the second axial direction (A2) with opposite handedness, and at the second axial end side open stent end (A2). 34a ) is in turn looped in the first axial direction (A1), wherein the same thread ( 22 ) at each helical reverse winding (RW) on the previously generated helical outward turns (HW) of the same thread ( 22 ) and the same thread ( 22 ) at each helical reverse winding (RW) on the previously generated helical outward turns (HW) of the same thread ( 22 ), wherein the loop-shaped deflections (SUa, SUb) form the first and second axial end-side open stent ends between the helical outward turns (HW) and the helical backward turns (RW). Stent ( 34 ) according to claim 19, wherein the helical Hin-windings (HW) are stored winding by winding in parallel side by side and the helical reverse windings (RW) are stored parallel to each other transverse to the Hin-windings (HW) winding by winding side by side and always alternately i ) the respective helical reverse winding (RW) are deposited on the underlying helical forward windings (HW) and ii) the respective helical forward turn (HW) on the underlying helical reverse windings (RW). Stent ( 34 ) according to one of claims 15 to 20, wherein the at least one superimposed thread ( 22 ) at least at some of the crossing points ( 32 ), in particular cohesively, is connected. Stent ( 34 ) according to one of claims 15 to 21, wherein the at least one superimposed thread ( 22 ) at least at some of the crossing points ( 32 ) is welded. Stent ( 34 ) according to one of claims 15 to 22, wherein the at least one superimposed thread ( 22 ) is connected or welded at several, but not at all crossing points. Stent ( 34 ) according to claim 23, wherein the proportion of connected or welded crossing points ( 32 ) in the total number of crossing points ( 31 . 32 ) ranges between 2.5% and 40%, preferably between 5% and 25%. Stent ( 34 ) according to any one of claims 15 to 24, wherein the crossing angle of the at least one superimposed thread ( 22 ) at the crossing points ( 31 . 32 ) in the range between 10 and 80 °, preferably in the range between 30 ° and 60 °. Stent ( 34 ) according to any one of claims 15 to 25, wherein the tubular helically wound scrim ( 30 ) is heat-set. Stent ( 34 ) according to one of claims 15 to 26, wherein the at least one thread ( 22 ) is selected from the following group of threads: - Nickel-titanium alloy thread, - Nitinol thread, - Magnesium or magnesium alloy thread - Medical grade stainless steel thread, - Cobalt alloy thread, - Thread made of a chromium alloy, cobalt-chromium alloy thread, niobium alloy thread, tantalum thread, platinum alloy thread, platinum-chromium alloy thread , - Polymer thread. Stent ( 34 ) according to one of claims 15 to 27, wherein the at least one thread ( 22 ) has a diameter in the range from 1 μm to 400 μm, preferably in the case of a blood vessel stent in the range between 10 μm and 150 μm, and preferably in the case of a pulmonary, tracheal, laryngeal, ureteral, gastrointestinal or bile duct stents in the range between 10 .mu.m and 300 .mu.m. Stent ( 34 ) according to one of claims 15 to 28, wherein the at least one thread ( 22 ) of the tubular helically wound gel ( 30 ) at a distance in the range of 0.5 mm to 5 mm, preferably in the case of a blood vessel stent in the range between 0.5 mm and 2 mm and preferably in the case of pulmonary, tracheal, laryngeal, ureteral, gastrointestinal or Bile duct stents in the range between 3 mm and 5 mm, is deposited. Stent ( 34 ) according to any one of claims 15 to 29, wherein the tubular wound scrim ( 30 ) in each case in the range between 3 and 150 helical windings, preferably in the range between 12 and 60 helical windings (HW, RW) in both axial directions. Stent ( 34 ) according to any one of claims 15 to 30, wherein the diameter of the tubular helically wound web ( 30 ) in the range between 0.1 mm and 25 mm, preferably in the case of a blood vessel stent in the range between 0.1 mm and 10 mm and preferably in the case of a pulmonary, tracheal, laryngeal, ureteral, gastrointestinal or bile duct stent in the range between 5 mm and 25 mm.

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