DE102009060279A1 - Device for supplying a medical implant and arrangement with such a device - Google Patents

Abstract

The invention relates to a device for feeding a medical implant (10) into a body cavity with a feed element (11), a holding surface (13) for the implant (10) being formed at one end (12a) of the feed element (11) , the end (12a) with the holding surface (13) can be placed in the body cavity and the holding surface (13) is adapted in such a way that the implant (10) can be detached from the holding surface (13) to be released in the body cavity.

Description

The invention relates to a device for delivering a medical implant having the features of the preamble of claim 1. Such a device for releasing a stent in a vessel is for example made EP 1374801 A1 known. The invention further relates to an arrangement comprising a device for delivering a medical implant into a body cavity, in particular into a vessel, and a medical implant.

Typically, when implanting a stent, an application system in the form of a catheter is placed in the vascular area to be treated, with the stent retained within the catheter tip, usually due to the radial restoring force created by the compression of the stent acting on the inner wall of the catheter. In the target vessel, a relative movement between the stent and the catheter tip causes the stent to be released from the delivery system. In strongly tortuous vessels, good catheter flexibility requires relatively high flexibility and, in addition, sufficiently high axial stability for moving the catheter in the vessel. A related improvement of existing application systems is in the old, post-published patent application to the applicant DE 10 2009 023 661.9 discloses a catheter tip having distally tapered inner wall of the applicant from the applicant. With this advancement, the loading of the vessels occurring during implantation of a stent can be reduced.

However, there is a widening of the vessel diameter due to the catheter wall. This is the case especially for small vessels. For example, if an uncrimped stent with a certain outside diameter is implanted, the overall diameter of the system will be at least the outside diameter of the stent plus twice the wall thickness of the catheter. Since the stent is usually oversized relative to the inner diameter of the vessel, the vessel is relatively heavily stressed during implantation due to the increase in the diameter of the application system due to the catheter. By crimping the stent, the system diameter can indeed be reduced. However, the possibility of introducing the stent in the crimped state through a catheter is not easily achievable in the case of very small vessels, for example in the case of vessels with dimensions in the region of 100 μm. Further limitations with regard to crimping may result from structurings or stent designs which are unsuitable for the implanted state.

The invention is based on the object to provide a device for supplying a medical implant, which is improved in view of a reduced stress on the vessel during implantation or during discharge of the implant from the device. The invention is further based on the object to provide an arrangement with such a device.

According to the invention the object is achieved with respect to the device by the subject-matter of claim 1 and with regard to the arrangement by the subject-matter of claim 13.

The invention is based on the idea to provide a device for supplying a medical implant in a body cavity with a supply element, wherein at one end of the supply element, a holding surface for the implant is formed. The end with the support surface is placeable in the body cavity, wherein the support surface is adapted such that the implant is releasable from the support surface for release in the body cavity. The holding surface is formed on an outer periphery of the feed element. The feed element has at least one hollow channel which extends into the region of the holding surface and is connected to at least one, in particular with a plurality of openings, which are formed in the holding surface. The hollow channel is connected to a suction device and / or a pressure device or connectable and forms a suction line and / or a pressure line such that the implant can be acted upon in use with a holding pressure for fixing the implant to the feed element and / or with a release pressure for releasing the implant is.

In contrast to known application systems, the device according to the invention provides the prerequisite for the implant being detachably connected to the feed element on the inner surface of its wall. Thus, the conventionally required in the prior art fixation of the implant on the outer surface of the implant wall can be omitted by the inside of the catheter tip. The device thus allows a particularly space-saving mounting for an implant, which is easily solvable in the region of the target vessel to be treated. The outer diameter of the application system in the region of the implant holder is thus determined in use by the outer diameter of the implant. Compared with known application systems, the system diameter in the region of the implant holder can be reduced by about twice the previous catheter wall.

The outer profile of the feed element is usually cylindrical. Other external profiles of the feed element are possible. The outer profile of the feed element can essentially the Inner profile of the implant correspond. Geometric deviations between the inner profile of the implant and outer profile of the feed element are possible.

The holder or the fixation of the implant on the feed element is effected by a negative pressure or a suction effect, which is generated by the user from the proximal and outside of the body. Due to the negative pressure, the implant is sucked in the region of the holding surface to the feed element and thereby fixed. In use, the implant is thus subjected to a holding pressure for fixing the implant to the feed element. By releasing the negative pressure or the holding pressure, the fixation of the implant can be easily solved.

As a pressure transfer medium, a liquid, for example. NaCl solution can be used.

The negative pressure is generated by the suction device, which is connected to the hollow channel in the feed element. The hollow channel extends in the region of the holding surface and is connected to at least one, in particular a plurality of openings, which are formed in the holding surface. As a result, the negative pressure is transmitted to the outer circumference of the feed element, so that an implant arranged in the region of the holding surface is sucked onto the feed element at least in regions and thus fixed.

For a sufficient fixation, it is not necessary that the implant rests on the entire circumference of the holding surface, where this is possible. It may be sufficient for a partial region of the inner surface of the implant wall to cover one or more of the openings formed in the holding surface, so that the negative pressure in this region acts on the implant wall and exerts the holding force.

With the device according to the invention also implants can be supplied, whose inner diameter is slightly larger than the outer diameter of the holding portion. This facilitates the removal of the delivery member from the implant once the vacuum is removed. In the abovementioned eccentric positioning or fixation of the implant relative to the feed element, only a portion of the inner surface of the implant wall rests on the holding surface and covers the openings formed there. In this case, it is also possible to form the openings mainly or exclusively on the side of the holding region where the eccentrically positioned implant rests against the holding surface. This is, for example, the holding situation for a cylindrical implant, such as a stent and a cylindrical feed element, whose outer diameter is slightly smaller than the inner diameter of the implant, in particular stents.

The hollow channel is alternatively or additionally connected to a pressure device or connectable such that the hollow channel forms a pressure line and can act on the implant to assist the release with a release pressure. This improves the safe and reliable discharge of the implant from the delivery system. The pressure transfer or the transmission of the release pressure takes place in the same way as the vacuum transfer, namely on the openings provided in the holding surface. As a result, a pressure is applied to the inner surface of the implant wall so that a radially outward release force acts on the implant wall. As a medium for pressurizing, a liquid such as a NaCl solution may be used. The delivery of the fluid associated with the positive pressure transfer also causes the delivery member to not only better disengage from the implant, but also slides better along the implant when the implant is positioned in the target vessel. A separation of the feed element and the implant is thus possible in a particularly safe and reliable manner. The release pressure functionality may be combined with a mechanical fixation of the implant instead of the suction fixation. In this alternative embodiment, the mechanical fixation is realized, for example, by a press fit between the implant and the holding surface of the feed element. By acting on the flexible implant wall with the release pressure, it is widened, so that the delivery element can be removed from the implant. The released implant remains in the target vessel. Due to the mechanical fixation of the implant, the formation of the hollow channel as a pressure line is sufficient. The suction line is not mandatory.

It is also possible to combine the release pressure functionality and the suction functionality, so that both the fixation and the release of the implant takes place by pressurization, in particular by exposure to overpressure and underpressure.

The pressure transmission can be done by one and the same line, in particular the hollow channel, since this takes place separately in time. It is also possible to provide a plurality of hollow channels, which have different functions, wherein, for example, a first hollow channel acts as a pressure line and a second hollow channel as a suction line. Further hollow channels can be provided, for example for the drug supply.

The device according to the invention has the advantage that the supply element with the holding surface for the implant does not necessarily have to be arranged in a catheter, but at least in sections, in particular in the region of the implant-fixing end of the supply element, can be fed into the target vessel independently of the catheter. Other, more proximal areas of the device may be guided in a catheter. Thus, the device according to the invention can also be used in connection with a catheter, wherein very small vessels can be achieved by the catheter-independent fixation of the implant on the inner surface of the implant wall. For this purpose, the distal end portion of the device, ie the feed element with the holding surface beyond the catheter tip also be advanced in the distal direction, so that the advantage of the small diameter of the application system comes into effect. This means that conventional catheters designed for transporting a fluid or a device in the inner lumen can still be used in conjunction with the device according to the invention, the advantage of the device according to the invention being that the positionability of the implant does not depend on the implant End region of the catheter is limited, but moreover is effective by the catheter-independent fixation on the feed element. The delivery element can thus be pushed out beyond the tip and fixes the implant independently of the catheter.

The device according to the invention is also suitable for the transcutaneous treatment of nearby vessels, especially in the eye. For supplying the medical implant in the body cavity, in particular in the vessel, this can be punctured by means of the device according to the invention, and advantageously at a location which is close to the site to be treated.

In general, the device according to the invention is useful for endoscopic applications. By an endoscope, in contrast to a catheter, we mean a somewhat stiffer system than a catheter, but it can also have a certain flexibility. An endoscope is usually not designed to transport a liquid or device in the inner lumen. Endoscopes are also usually sterilizable systems and have a higher mechanical stability. They are also shorter than catheters, which are usually delivered through longer cavities. Thus, the aspect ratio length / thickness is smaller in endoscopes than in catheters. In the treatment of an eye can be spoken of an endoscopic application rather because the vessel to be treated is very close to the main and the application system should be rather stiff. The telescopic embodiments of the invention disclosed elsewhere for passage through peripheral vessels may be referred to as a catheter application. Ultimately, in both cases are devices for the supply of medical implants in a hollow body organ, in particular in a vessel. In this application, when endoscopic treatments are addressed, in general, the o. G. design and handling-related features, wherein the transport or supply of an implant is the goal of the device.

A further advantage of the device according to the invention, in particular of the delivery element in relation to the application of implants through catheters, relates to the ratio wall / inner diameter of the delivery system. In conventional catheters, the wall should be as thin as possible, thereby providing more space for the implant without increasing the outside diameter of the catheter. However, the thin wall of the catheter can lead to collapse of the system. Therefore, catheters are made of multiple layers of different materials and braiding / coil reinforcement. However, such systems are very expensive. In addition, the stability of such a system may still be inadequate despite the reinforcement. The application system according to the invention has the advantage that the lumen can be made much smaller in relation to the overall diameter of the system than in known systems. Thus, the ratio wall thickness / outer diameter is greater than in known systems. No large lumen of the hollow channel is required to effect the vacuum or, for example, sufficient delivery of medicaments or fluids through the delivery member. The system according to the invention or the device according to the invention is therefore more stable than known application systems and can be produced, for example, from a single material without increasing the risk of collapse or breakage. The production of different materials is not excluded.

In the context of the invention, the device for supplying a medical implant both without the implant (claim 1) and with the implant in the form of an arrangement comprising such a device and a medical implant (claim 14) is disclosed and claimed.

In a preferred embodiment, radially arranged side channels are provided which connect the hollow channel and the openings in the holding surface. As a result, the transmission of the negative pressure from the hollow channel to the holding surface of the feed element is achieved in a simple manner.

The delivery member may include a tip that is disposed distal to the support surface by the user and configured to urge a calculus, particularly a thrombus, through the tip to the vessel wall in use and / or to puncture a vessel or tissue. This facilitates the placement of the holding surface with the fixed implant adjacent to the thrombus. It is also possible to use the sharp tip for puncturing. Preferably, the tip in longitudinal section two, with respect to the longitudinal axis of the feed element, differently inclined sides or a side parallel to the longitudinal axis of the feed element and an oblique side. This improves the operability of the delivery element in the vessel, since the distal end of the tip is arranged as close as possible to the vessel wall when the tip is moved past the thrombus. The delivery member may have more flexibility at its tip than in a user-proximal portion of the delivery member. This makes it possible to move and maneuver the delivery member from the applicant or generally from a proximal position with good transfer, the flexible tip allows adaptation to the vessel / cavity geometry. The different flexibility ranges of the feed element can be achieved by the combination of different materials, which are explained in detail elsewhere, and / or by geometric relationships. For example, the feed element can have a user-proximal region that has a larger diameter than a distal region of the delivery element, in particular a distal region, which is adjoined by the tip.

In a further preferred embodiment, the hollow channel is connected or connectable to a supply device for medicaments and / or liquids, such that the hollow channel forms both a suction line and a medicament supply and / or liquid supply. This has the advantage that the hollow channel fulfills two functions, namely the suction and / or pressure function as well as the drug supply and / or fluid supply, whereby the versatility of the application system or the device for supplying the medical implant is extended. Preferably, the hollow channel has a drug delivery / fluid delivery outlet port provided at the end of the delivery member. This has the advantage that the drugs used for the treatment can be released directly in the target vessel.

The hollow channel may have at least one valve which, as seen by the user, is arranged distally downstream of the openings or proximally upstream and which closes the hollow channel in the suction or pressure mode. This prevents blood from entering the hollow channel in the suction mode or the medium in the hollow channel exiting in the pressure mode, for example, through a possible outlet opening for the supply of medicament.

The hollow channel may have at least one further opening, which is formed at the end of the feed element for sucking and holding a concretion, in particular a thrombus. The embodiment has the advantage that, by sucking and fixing the thrombus on the delivery element, it may possibly be mechanically removed from the vessel. If this is not possible, then the implant can be placed in the target vessel as originally intended to push the thrombus against the vessel wall and open the vessel.

The feed element with the holding surface and at least one first hose-like feed element can be arranged telescopically in one another. This embodiment is particularly suitable for the treatment of remote vessels, in which only in the last section in front of the target vessel, the reduced outer diameter of the application system is significant. In this case, the first supply element and at least one second hose-like supply element can be arranged telescopically displaceable one inside the other, whereby the length of the device can be increased. The feed element preferably has a varying diameter, namely a diameter which changes in the longitudinal direction of the feed element. The diameter of the delivery element becomes larger in the proximal direction, ie towards the user. This facilitates the feedability of the feed element. This will be described in the context of the two following embodiments, namely in the case where the supply element reaches the user and in the event that the supply element is shorter and is displaced by a pusher in the catheter.

The supply element with the holding surface may be formed in its length so that a user-viewed from the proximal end of the feed element in the fully extended state by the user is actuated. Thus, at maximum length, ie at fully telescoped telescoping feed elements, the proximal end of the feed element with the holding surface of the user tangible. This facilitates or simplifies the handling or actuation of the feed element with the holding surface for the implant. At the catheter end, a stop may be formed, the function of which is to block the internally located element, for example, the supply element in its axial Ausschubbewegung when the predetermined extension stroke of the feed element is achieved with the support surface.

The feed element with the holding surface can be arranged to be relatively movable in a line, in particular in a catheter, wherein the hollow channel formed in the feed element is either connected or connectable by the line to the suction device and / or the pressure device and / or the drug supply device. In this embodiment, a conventional catheter may be used to guide the delivery member to the support surface, with the delivery member being moved with the support surface, for example, by a pusher. The direction of the catheter has two functions. On the one hand, the conduit serves the mechanical guidance of the feed element, on the other hand, the line connects the hollow channel in the feed element with an actuating device which is arranged outside the line, for example with a suction device, and / or a pressure device, and / or a drug delivery device. The sealing of the feed element against the inner surface of the conduit of the catheter takes place in a manner familiar to the person skilled in the art.

The invention is further based on the idea to provide an arrangement comprising a device according to the invention and a medical implant, which is fixable in the region of the holding surface on the feed element, wherein the implant has a wall with at least one holding and / or release area, which in use at least one opening in the holding surface is covered and can be acted upon by a holding force, which is generated in use by the suction effect. The holding force acts radially inwards. For the holding and / or release area or the suction area each area closed surface of the wall is suitable. Also, a wall with a porous structure can be sucked by the feed element. For example, the porous structures or the holding and / or release region of the implant can be smaller than the openings in the holding region or in the holding surface. In this case, the openings are partially closed and partially uncovered. The suction effect can be achieved under these conditions in that the size of the openings, in particular their diameter, is adjusted so that due to the surface tension in the open, uncovered areas of the openings no liquid is sucked into the hollow channel. Thus, a pressure loss is prevented and acts on the implant wall which required for the fixation of the implant holding force. By a porous structure is meant, for example, a film with very fine perforations.

It is not necessary that the entire wall is closed continuously, also an embodiment of the implant with a continuous closed wall in connection with the invention is disclosed. It is sufficient if the suction regions of the wall have a slightly larger diameter than the openings formed in the holding surface, so that the openings can be completely covered by the suction region and thus subjected to a negative pressure. The assignment of the suction regions or the holding and / or release regions of the implant wall to the openings in the holding surface can be effected either by an alignment of the implant on the holding surface, such that the holding and / or releasing regions or at least a part of the holding and / or release areas are aligned with the openings. It is also possible to achieve sufficient coverage of the openings in the support surface by a large number of openings and holding and / or release areas, so that statistically the probability of overlap is sufficiently high. Thus, the holding and / or release areas and the openings formed in the holding surface can be designed statistically or by the geometric arrangement so that the probability of (partial) coverage is 100%.

In principle, a single opening, which cooperates with a suction region or a holding and / or release region of the implant wall, is sufficient for fixing the implant. Preferably, a plurality of openings are provided in the holding surface, which cooperate with a correspondingly large holding and / or release area or with a plurality of small holding and / or release areas. The openings may be arranged distributed in the longitudinal direction and / or circumferential direction of the feed element.

The holding and / or releasing area is a region of the wall which is suitable for being pressurized in such a way that a radially inwardly directed force (holding force) and / or a radially outward force (releasing force) acts on the wall ,

In the preferred embodiment, the wall comprises a rotationally symmetrical, in particular a cylindrical wall, which is rigid or flexible. The flexible wall may have a longitudinal slot. The rigid implant wall is suitable for particularly small vessels where the implant diameter is so small that crimping of the implant is not possible. The flexible implant wall is suitable for slightly larger vessels, where a reduction in the diameter of the implant by the suction and / or by crimping the implant is possible.

The flexibility of the wall can be achieved for example by a longitudinal slot formed in the wall, through which the wall can be widened or reduced in diameter. The wall may alternatively or in addition to the longitudinal slot be structured by a perforation, wherein the ratio between the material surface and the entire wall surface more than 20%, in particular more than 30%, in particular more than 40%, in particular more than 50%, in particular more than 60%, in particular more than 70%, in particular more than 80%, in particular more than 90%. The perforation improves the longitudinal expansion of the implant wall.

The term flexibility is understood as meaning both the flexibility of the wall in the circumferential direction and the flexibility of the wall in the longitudinal direction. The flexibility of the wall in the circumferential direction is made possible, for example, by the longitudinal slot in the wall and allows a kind of crimping of the implant to very small diameters. The flexibility in the longitudinal direction is to be understood in the context of the curvature of the implant, which can occur, for example, in tortuous vessels. The flexibility of the wall for such curvatures is made possible, for example, by the perforation, which supports an extension of the structure or the implant on the curved outer diameter. The invention will be explained in more detail below with reference to exemplary embodiments with reference to the attached schematic drawings with further details. In these show:

1 a longitudinal section through a supply element of a device according to an embodiment of the invention, in which an implant is arranged on the holding surface;

2 the feed element according to 1 when connected to a crimped implant disposed in an introducer sheath;

3a . 3b a cross section through the feed element according to 1 with fixed implant and with dissolved or released implant in the target vessel;

4a . 4c the feed element according to 1 in three different states when removing an in-vessel implant;

5a . 5b a plan view of a unwound implant with perforation in the unstretched and in the longitudinally stretched state;

6a . 6b a longitudinal section through the supply element of a device according to another embodiment of the invention in the treatment of a thrombus;

7 a cross section through the supply element of a device according to another embodiment of the invention, in which the tip fulfills a suction function;

8th a longitudinal section through a supply element of a device according to another embodiment of the invention, which is telescopic; and

9 the arrangement of the feed element according to 8th in differently sized vessels with different bifurcations.

In 1 an embodiment of the device according to the invention is shown, which is particularly suitable for the treatment of vascular occlusions or constrictions by implants, or by vascular supports, such as stents. With the device, other implants can be supplied. The device is suitable in particular for the treatment of vessels with a diameter of less than 300 μm, in particular less than 200 μm, in particular less than 150 μm, in particular less than 100 μm, without being restricted thereto.

The device according to 1 can be used, for example, for the treatment of an arterial or venous occlusion in the eye area. A closure in the eye area can occur for two main reasons. On the one hand, a thrombus occludes the vessel, either in the artery or in the vein. On the other hand, you can press an artery against the vein and close it. The invention is not limited to this application nor to the dimensions mentioned above. Rather, the invention can also be used successfully for the treatment of vessels or cavities with a larger diameter or for other medical applications.

The embodiment according to 1 shows in longitudinal section the feed element 11 a device according to an embodiment of the invention. The device may comprise further elements, for example, ports or actuators associated with the illustrated feed element 11 are connected or interact with this. In particular, the feed element 11 proximally with hoses, tubes, in particular with hoses with a larger diameter than the feed element 11 , or be connected to other supply and handle elements (not shown). The device can also only from the feed element 11 consist. The feed element 11 is the part of the device placed in the target vessel around the implant 10 to dismiss there. For this purpose has an end, in particular a first end 12a of the feed element 11 a holding surface 13 for the implant 10 on. The first end 12a of The delivery element is distally positioned as seen by the user or constitutes the distal end.

The term distal refers to more distant from the user components or sections of an element. The term proximal designates closer to the user arranged components or sections of components.

The feed element 11 is an elongated rotationally symmetrical, in particular cylindrical body which can be actuated or handled by the user, for example for puncturing a vessel or for an endoscopic application. The feed element 11 forms the last or outermost element of the application system distally from the user, which is guided to the target vessel.

The feed element 11 has a distal end 12a and a proximal end 12b on. In the area of the distal end 12a or at the distal end 12a of the feed element 11 is a holding surface 13 for the implant 10 intended. The length of the holding surface 13 corresponds approximately to the implant length or is slightly longer. The holding surface 13 forms the seat of the implant 10 when inserted into the vessel. In the simplest case, the feed element 11 a constant diameter over its entire length, including at the level of the holding surface 13 on. It is also possible, as in the embodiment according to 1 shown that the outer diameter in the area of the holding surface 13 is smaller than the outer diameter in a proximal portion of the feed element 11 ,

As in 1 shown, is the holding surface 13 on the outer circumference of the feed element 11 educated. This causes the fixation of the implant 10 takes place on the inner surface, at least partially on the support surface 13 is applied. This determines the outer diameter of the implant 10 the total diameter of the application system in the area of the holding surface 13 , The outer diameter of the overall system is therefore smaller than in innenfixierenden catheters.

The circumferential profile of the holding surface 13 is to the inner profile of the implant to be fixed 10 customized. In the embodiment according to 1 is the circumferential profile of the holding surface 13 rotationally symmetrical, in particular cylindrical. Other profile shapes are possible.

With regard to the dimensions, for example, the inner diameter of the implant may be slightly larger than the outer diameter of the feed element 11 , in particular the holding surface 13 of the feed element 11 , This will remove the feed element 11 from the implant 10 further eased. It is also possible that the inner diameter of the implant and the outer diameter of the feed element 11 , in particular in the area of the holding surface 13 is equal to. It is even conceivable that between the implant and the holding surface 13 an interference fit exists when the implant is radially deformable, for example by a perforation or by a longitudinal slot. This will be the discharge of the implant 10 facilitated by a pressurizing pressure. It is also possible that the friction of the vessel wall is greater than the friction between the implant and the feed element 11 to the implant 10 from the feed element 11 slough. For this purpose, acting as a stop transition region 27 according to 1 advantageous (mechanical fixation). The implant can be displaced distally, with both the negative pressure and the stop preventing the implant from shifting in the proximal direction. The discharge takes place by interrupting the negative pressure and pulling the supply element against the friction of the vessel wall. The friction can either by a corresponding surface and / or structuring of the feed element 11 or be achieved by the pure overstretching of the vessel.

This means that the holding function can be achieved in various ways, for example, by an exclusively mechanical fixation of the implant or by a combined mechanical and negative pressure assisted fixation or by an exclusively vacuum-assisted fixation of the implant.

The holding function of the feed element 11 is through at least one hollow channel 14 reached in the feed element 11 is trained. The hollow channel 14 extends from the proximal end 12b of the feed element 11 in the area of the holding surface 13 , The hollow channel 14 is at the proximal second end 12b accessible through an entrance opening 25 , The entrance opening 25 is on the front side of the feed element 11 in the region of the proximal end 12b educated. The hollow channel 14 runs coaxially to the longitudinal axis of the feed element 11 , It is also possible to use the hollow channel 14 eccentrically with respect to the longitudinal axis of the feed element 11 to arrange.

The hollow channel 14 extends in the area of the holding surface 13 and is in an area below the holding surface 13 educated. In the embodiment according to 1 extends the hollow channel 14 almost over the entire length of the holding surface 13 , It is also possible to use the hollow channel 14 shorter, such that this the holding surface 13 not complete, as in 1 but only partially overlapped.

There are also several hollow channels possible, for example, a channel for suction (suction line) and a channel for conveying (pressure line), so that a separation of functions takes place

The hollow channel 14 is with several openings 15 connected in the holding area 13 are formed. The openings 15 allow fluid communication between the hollow channel 14 and the inner surface of the implant 10 that on the feed element 11 is fixed. As in 1 are shown along the longitudinal direction of the support surface 13 several openings 15 intended. In the embodiment according to 1 are concretely 12 arranged in a longitudinal plane openings 16 in the holding area 13 educated. Another number of openings 15 in the longitudinal direction of the holding surface 14 is possible. For example, in principle, a single opening 15 be enough. In particular, at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 11, at least 12 openings 15 be provided in the longitudinal plane. As in the 3a . 3b are shown, also in the circumferential direction of the feed element in the region of the holding surface a plurality of openings 15 provided, for example, eight openings may be provided distributed on the circumference in a cross-sectional plane. Again, there are different numbers of openings 15 possible, with reference to the disclosure of the number of openings in connection with the above-mentioned longitudinal arrangement of the openings.

The openings 15 may be circular. Other opening profiles, such as oval or slot-shaped are possible.

The openings 15 are with the hollow channel 14 through side channels 16 connected, extending radially between the hollow channel 14 and the openings 15 in the feed element 11 extend. The hollow channel 14 is at the distal end 12a closed, so that the total suction power at the holding surface 13 is applied. The distal closure of the hollow channel 14 takes place in a simple manner by a closed end face 26 in the area of the distal first end 12a ,

The hollow channel 14 is with an in 1 Suction device not shown connected or connectable and forms a suction line. By the suction device, a negative pressure is generated, passing through the hollow channel 14 and the side channels 16 on the openings 15 and thus on the holding surface 13 is transmitted. The resulting suction effect makes the implant 10 in use on the feed element 11 fixed. In 1 is for illustrative purposes between the implant wall and the support surface 13 drawn a gap. In practice, the implant wall is located on the holding surface 13 at. It is also possible that the implant wall only partially on the support surface 13 is applied, wherein in the adjacent region of the implant wall, the fixing holding force on the implant 10 is applied. One between the remaining area of the implant wall and the holding surface 13 present gap is harmless.

Even in the areas where a gap exists, a suction effect can be caused by the negative pressure. Due to the small dimensions of the gap can be achieved that due to the surface tension no liquid penetrates into the conduit. It is possible that the implant rests only at certain points on the holding surface. It is possible that the gap extends over the entire circumference. The gap is formed by an angle of 360 °. For example, the implant abuts only at the ends of the implant. In general, the holding and / or release area of the wall can be interrupted both along the length and along the circumference.

Reducing the entire area where the implant rests reduces implant removal force when the vacuum is broken and the delivery member is pulled proximally.

The holding and / or release region of the wall generally forms the contact surface between the implant 10 and feed element 11 or holding surface 13 ,

The feed element 11 has a tapered in the distal direction, in particular conically tapered transition region 27 on. The transition area 27 For example, it can serve as a stop on a telescopic system that provides longitudinal movement of the feed element 11 limited. Furthermore, the transition area 27 when loading the application system with the implant as a stop for the implant 10 act. In the embodiment according to 1 connects the transition area 27 the distal end 12a with the holding surface 13 and the proximal end 12b , in which the hollow channel 14 is trained. The outer diameter of the proximal end 12b is greater than the outer diameter of the distal end 12a with the holding surface 13 ,

The feed element 11 can also be referred to as a tube.

In the embodiment according to 1 the implant is loaded in the uncrimped state. It is also possible, as in 2 represented, the implant on the tube or on the holding surface 13 to crimp the feed element. In this case, as indicated by the arrow in 2 shows the system before use within an external lock or introducer sheath 28 crimped. The implant, especially the stent is in the introducer sheath 28 held and the holding surface 13 gets along with the distal end 12a of the feed element 11 in the implant 10 or introduced the stent. Then the negative pressure on the hollow channel 14 to the holding surface 13 created, whereby the implant or the stent 10 to the tube or the holding surface 13 is sucked. The crimping of the implant or of the stent has the advantage that the dimensions of the entire system can be reduced in relation to the dimensions of the vessel. This reduces the stress on the vessel wall.

For suction fixation by the feed element 11 For example, implants, in particular stents, which have suction regions, ie regions in which the implant wall is closed, are generally suitable, so that a negative pressure acting on the closed surface in this region can affect the implant 10 at the holding surface 13 fixed. In the simplest case, the entire implant wall is closed. It is also sufficient that discrete intake regions are formed, which is achieved for example by a partial covering of the implant or the lattice structure of the implant. For sputtered stents, the areas between perforations may act as suction areas. Even with braided stents or implants, it is possible to use the crossings of the wires as suction areas. The openings 15 can with the intake areas 23 be aligned such that the intake areas 23 (please refer 5a . 5b ) with the openings 15 are aligned. It is also possible that the openings 15 be arranged so that the implant 10 or the stent does not need to be aligned, but in any position on the support surface 13 enclosed area or an intake area 23 at the height of an opening 15 is located or aligned with this.

The intake area (s) 23 correspond to the holding and / or release areas and are generally area that can be acted upon by a pressure to generate a force.

The implant 10 or the stent may be a circumferentially closed cylinder that is not flexible and not crimpable. The inner diameter of the cylinder is slightly larger than the outer diameter of the distal end 12a of the feed element 11 , When fixing a part of the inner surface of the cylinder is located on the support surface 13 at. A non-flexible implant is particularly useful when the length is limited and the vessel is relatively straight.

It is also possible to use an implant with a flexible wall, ie with a flexibility in the radial direction, which can be crimped or radially deformed, with the application system according to FIG 1 to use, which has the advantage that the wall almost completely or at least in a larger area than a rigid implant to the support surface 13 invests. An example of an implant 10 with a flexible wall is in the 3a . 3b shown. The implant also has a cylindrical shape here. Through the longitudinal slot 29 the lumen or the inner diameter of the implant is variable. When expanded, the implant has, as in 3b represented, in cross section a C-shape. As a result, a particularly simple crimping of the implant is possible without complex structural geometries are required.

As in the 5a . 5b shown in the implant wall structuring in the form of perforations 24 be provided, which improves the flexible behavior of the implant (see 5b ). The implant according to the 5a . 5b (unwound state) indicates due to the perforation 24 a structure that allows extension of the implant ( 5b ). This allows the implant 10 Extend in tortuous vessel areas at the outer radius of the curved, adapted to the tortuous vessel areas implant. The perforated structure also has the advantage that the endothelialization is favored.

Examples of suitable perforation geometries are disclosed in the copending applications entitled "Medical Implant and Method of Making Such Implant" and "Medical Device", which are assigned to the Applicant and incorporated herein by reference in their entirety.

In 5a is also shown that the suction 23 To form those closed areas of the implant wall that are located between the perforations 24 are located.

The operation of the device according to 1 or according to 2 is in the 3a and 3b shown. This mode of operation applies to all embodiments disclosed in the application in which a flexible implant 10 is used. As in 3a shown holding the over the hollow channel 14 and the side channels 16 on the holding surface 13 transferred negative pressure the implant 10 or the C-shaped stent. If the negative pressure is released, the implant dissolves 10 from the holding surface 13 and unfolds to the vessel wall 30 , The release of the implant 10 from the feed element 11 can be supported by that over the hollow channel 14 and the side channels 16 an overpressure on the implant 10 which is the unfolding of the implant 10 supported.

In the 4a to 4c It is shown that the delivery element or in general the device for supplying a medical implant can not be used only for releasing the implant in the vessel. It is also possible to remove an implant or stent released in the vessel from the vessel. The device thus serves not only as a delivery system but also as a return system for implants.

This is the holding surface 13 brought to the implant inner wall ( 4a ), at the same time a negative pressure at the openings 15 is created. Then the feed element becomes 11 rotated as indicated by the arrow 4b clarified and indeed in the implant into it. As a result, an increasing part of the inner surface of the implant comes into contact with the holding surface 13 passing through the openings 15 the implant wall, as far as these the openings 15 cover, suck and hold. In 4c It is shown that the entire inner surface of the implant on the support surface 13 is applied and sucked by this. The outer diameter of the implant 10 is thus reduced so far that the implant 10 can be removed from the vessel. This possibility of use also applies to all embodiments in this application.

6a . 6b show further embodiments of the device according to the invention. In these embodiments, a tip is 17 at the distal end 12a of the feed element 11 arranged. Specifically, the tip is 17 at the frontal area 26 the distal end 12a provided and extends in extension of the support surface 13 in the distal direction. In general, the tip can be shaped like the tip of a known puncture needle. The summit 17 has the function of pushing a thrombus to the vessel wall before the retaining surface 13 with the implant 10 pushed forward and the implant is released in the target vessel ( 6b ). The summit 17 has a first side in cross section 18a and a second page 18b , The first page 18a is, relative to a longitudinal axis of the feed element 11 , inclined. The second page 18b the top 17 extends parallel to the longitudinal axis of the feed element 11 , This creates a particularly favorable profile of the tip, which causes the tip 17 between the thrombus 31 and the vessel wall 30 can be moved without damaging the thrombus ( 6a ). It is also possible the two sides 18a . 18b to arrange differently inclined relative to the longitudinal axis of the feed element.

In 7 is shown a further embodiment in which the hollow channel 14 completely through the proximal end 12a extends through and an opening 19 which has the hollow channel 14 connects with the environment. The opening 19 can be either in the face 26 , or if on the frontal surface 26 the summit 17 is arranged, in the first, inclined side 18a the top 17 be educated. Through the continuous hollow channel 14 according to 7 For example, drugs can be administered as soon as the implant 10 or the stent is in the vessel and the hollow channel 14 no longer required as a vacuum channel or suction channel.

For example, thrombuslösende drugs through the hollow channel 14 administer. Another application of the hollow channel 14 is to use this to aspirate the thrombus. Thus, an attempt can be made to remove the thrombus in this way from the vessel before the implant 10 or the stent is discharged. This is the hollow channel 14 either connected to a drug delivery device or with the suction device, which anyway for fixing the implant 10 is required. In the embodiment according to 7 it is also possible to use the feed element 11 Initially, without implant, with the primary goal being to aspirate the thrombus, at the top 17 to fix and so to remove from the vessel. At this point it is again pointed out that the feed element 11 or the associated device both with the implant 10 (in the form of an assembly) as well as without the implant 10 disclosed and claimed.

Due to the negative pressure, it can happen that the hollow channel 14 Blood sucks, passing through the very narrow capillary openings 15 Only small blood flows arise in the hollow channel 14 reach. This also applies to the further opening 19 for drug delivery. There is a possibility, the top 17 to be provided with a valve (not shown), so that the blood flow takes place only in the direction of the tip, ie away from the user, and not in the direction towards the user.

The embodiment according to 8th has a telescopic structure, which has the advantage that the sliding of the system or the movement in the distal direction during placement of the implant is improved, especially in areas outside of the target vessel. The feed element 11 can be very thin and flexible thereby preserving the advantages of implanting stents in very small vessels. The telescopic insert is intended for endovascular treatment in which a critical vessel is reached from a peripheral vessel. This is how in 8th illustrated, provided that the feed element 11 and a proximal of the feed element arranged tubular further feed element 20a telescopically slidable. As in 8a shown forms the conical transition region 27 a stop for the hose-like feed element 20a whose distal end is complementary to the stop or to the transition region 27 is trained. Concretely, the inner wall of the distal end of the hose-like feed element tapers 20a in the distal direction. The hose-like feed element 20a is in another hose-like feed element 20b guided, which in turn can be telescopically mounted. Alternatively, the first tube-like feed element 20a in the pipe 21 be guided by a catheter.

The feed element 11 with the holding surface 13 forms the distal outermost element of the delivery system according to 8th , The different elements 11 . 20a . 20b are relatively movable to each other. It is possible that all elements 11 . 20a . 20b reach the user, allowing the user the proximal end of all elements 11 . 20a . 20b can see and operate.

It is also possible that the user only a part of the feed elements 11 . 20a . 20b sees and can press directly. Removal of the pushers will increase the total suction lumen and increase suction and / or reduce the pressure necessary to deliver medication. Alternatively, the user may select the feed elements 11 . 20a . 20b , in particular the feed element 11 with the holding surface 13 move distally through a pusher. The pushers can be the inner elements, such as the feed element 11 with the holding surface 13 or move the tube and then uncouple. It is also possible that the pusher (s) enable a retract function.

In 9 is the interventional use of the application system with the telescopic structure according to 8th shown. In this case, the entire catheter or the line 21 introduced through the femoral artery. The pushability of the system is ensured in the large vessels. Due to the telescopic structure of the delivery system, it is able to penetrate into the branched small vessels ( 9 ). It is also possible that the individual catheters or supply elements are preformed in such a way that they follow the anatomy in the region of the corresponding bifurcations. The output of each catheter or delivery element from the next larger catheter or supply element can also be made laterally, for example by laterally aligned recesses in the catheters or supply elements.

• – Außendurchmesser: ≤ 1,2 mm, insbesondere ≤ 1 mm, insbesondere ≤ 0,8 mm, insbesondere ≤ 0,6 mm, insbesondere ≤ 0,4 mm, insbesondere ≤ 0,3 mm.
• – Wandstärke: ≤ 200 µm, insbesondere ≤ 150 µm, insbesondere ≤ 100 µm, insbesondere ≤ 50 µm, insbesondere ≤ 40 µm, insbesondere ≤ 30 µm, insbesondere ≤ 20 µm, insbesondere ≤ 10 µm.

The following dimensions of the tube or the feeding element 11 are suitable for the treatment of small vessels with a diameter of between 500 μm and 1 mm:

• - Outer diameter: ≤ 1.2 mm, in particular ≤ 1 mm, in particular ≤ 0.8 mm, in particular ≤ 0.6 mm, in particular ≤ 0.4 mm, in particular ≤ 0.3 mm.
• Wall thickness: ≤ 200 μm, in particular ≤ 150 μm, in particular ≤ 100 μm, in particular ≤ 50 μm, in particular ≤ 40 μm, in particular ≤ 30 μm, in particular ≤ 20 μm, in particular ≤ 10 μm.

By outer diameter is meant the diameter on which the stent sits, ie the diameter of the distal end 12a in the area of the holding surface 13 ,

• – Außendurchmesser: ≤ 0,8 mm, insbesondere ≤ 0,6 mm, insbesondere ≤ 0,4 mm, insbesondere ≤ 0,2 mm, insbesondere ≤ 0,15 mm, insbesondere ≤ 0,12 mm, insbesondere ≤ 0,10 mm.
• – Wandstärke: ≤ 150 µm, insbesondere ≤ 100 µm, insbesondere ≤ 50 µm, insbesondere ≤ 40 µm, insbesondere ≤ 30 µm, insbesondere ≤ 20 µm, insbesondere ≤ 10 µm, insbesondere ≤ 5 µm.

For the treatment of vessels with a diameter of less than 500 microns, the following dimensions of the feed element 11 in the area of the holding surface 13 proved to be useful:

• - Outer diameter: ≤ 0.8 mm, in particular ≤ 0.6 mm, in particular ≤ 0.4 mm, in particular ≤ 0.2 mm, in particular ≤ 0.15 mm, in particular ≤ 0.12 mm, in particular ≤ 0.10 mm ,
• Wall thickness: ≤ 150 μm, in particular ≤ 100 μm, in particular ≤ 50 μm, in particular ≤ 40 μm, in particular ≤ 30 μm, in particular ≤ 20 μm, in particular ≤ 10 μm, in particular ≤ 5 μm.

The above-mentioned outer diameters can be applied to a region with a length of ≦ 10 mm, in particular ≦ 8 mm, in particular ≦ 6 mm, in particular less than 4 mm, in particular ≦ 3 mm, in particular ≦ 2 mm in the region of the distal end 12a , So where the stent or the implant is fixed, be limited.

• – Stents mit Durchmesser zwischen 200 µm und 1 mm. Der Stent weist eine Wandstärke auf, die kleiner als 5/100, insbesondere kleiner als 2/100, insbesondere kleiner als 1/100 des Durchmessers ist. Beispiele:
• – Stent mit Durchmesser 1 mm, Wandung kleiner als 50 µm, insbesondere kleiner als 10 µm
• – Stent mit Durchmesser 500 µm, Wandung kleiner als 25 µm, insbesondere kleiner als 5 µm
• – Stent mit Durchmesser kleiner als 200 µm. Der Stent weist eine Wandstärke auf, die kleiner als 10/100, insbesondere kleiner als 8/100, insbesondere kleiner als 5/100, insbesondere kleiner als 3/100 des Durchmessers ist. Beispiele:
• – Stent mit Durchmesser 200 µm, Wandung kleiner als 20 µm, insbesondere kleiner als 6 µm
• – Stent mit Durchmesser 100 µm, Wandung kleiner als 10 µm, insbesondere kleiner als 3 µm
• – Stent mit Durchmesser 500 µm, Wandung kleiner als 25 µm, insbesondere kleiner als 5 µm

The following values are possible for the dimensions of the stent:

• - Stents with a diameter between 200 μm and 1 mm. The stent has a wall thickness which is less than 5/100, in particular less than 2/100, in particular less than 1/100 of the diameter. Examples:
• - Stent with a diameter of 1 mm, wall smaller than 50 microns, especially smaller than 10 microns
• - Stent with a diameter of 500 microns, wall less than 25 microns, especially less than 5 microns
• - stent with a diameter smaller than 200 μm. The stent has a wall thickness which is less than 10/100, in particular less than 8/100, in particular less than 5/100, in particular less than 3/100 of the diameter. Examples:
• - Stent with a diameter of 200 microns, wall less than 20 microns, especially less than 6 microns
• - Stent with a diameter of 100 microns, wall less than 10 microns, especially less than 3 microns
• - Stent with a diameter of 500 microns, wall less than 25 microns, especially less than 5 microns

It is also possible to use very thin-walled, sputtered stents or implants. The thickness of the wall of such stents is ≦ 15 μm, in particular ≦ 12 μm, in particular ≦ 10 μm, in particular ≦ 8 μm, in particular ≦ 6 μm, in particular ≦ 5 μm, in particular ≦ 4 μm, in particular ≦ 3 μm.

The diameter of the feed element 11 in the amount of the holding means or the holding surface 13 is ≤ 1 mm, in particular ≤ 500 μm, in particular ≤ 200 μm, in particular ≤ 150 μm, in particular ≤ 120 μm, in particular ≤ 100 μm, in particular ≤ 80 μm, in particular ≤ 60 μm.

The implant can be made by a sputtering technique and photolithographic etching, both cylindrical and planar, which is then rolled cylindrically. The advantage of this is that the structure is very flat and can be sucked in very well. It is also possible to braid the implant, in particular the stent, wherein the wires have a diameter of ≤ 10 μm, in particular ≤ 5 μm.

Materials for the tube (feed element 11 ) can be: glass, plastic, ceramics and super elastic metal like Nitinol. For example, the tube can be cylindrically sputtered using a very thin copper wire as the carrier. The preparation of the delivery element can be done as in the stent. The advantage of glass, ceramics and NiTinol is that the thin tubes will not plastically deform even with large deformations or forces, which could affect the accuracy of the treatment. Additional materials may include radiopaque materials such as tungsten, platinum-iridium, iridium or iridium alloys. Also stainless steel is possible.

The suction function can be fulfilled as follows: A vacuum chamber can be connected to the proximal end of the feed element. It can be in the form of a soft pipette, possibly filled with a liquid that is pressed together before the implant is placed on the holding surface of the tube. The operation can be carried out before use so that the negative pressure does not exist in the packaging and decreases due to leaks in storage time. The overpressure chamber can be constructed accordingly.

Furthermore, the application discloses both the use of the device for supplying the medical implant for the treatment of eye diseases and a method for the treatment of eye diseases with the device for supplying the medical implant according to this application.

LIST OF REFERENCE NUMBERS

10

implant

11

supply element

12a

End / first end

12b

End / second end

13

holding surface

14

hollow channel

15

openings

16

side channels

17

top

18a, 18b

Sides of the top

19

opening

20a

first hose-like feed element

20b

second hose-like feed element

21

management

22

wall

23

suction

24

perforation

25

inlet opening

26

face

27

Transition area

28

introducer

29

longitudinal slot

30

vessel wall

31

thrombus

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 1374801 A1 [0001]
• DE 102009023661 [0002]

Claims (15)

Device for supplying a medical implant ( 10 ) in a body cavity with a feed element ( 11 ), whereby at one end ( 12a ) of the feed element ( 11 ) a holding surface ( 13 ) for the implant ( 10 ), the end ( 12a ) with the holding surface ( 13 ) is placeable in the body cavity and the holding surface ( 13 ) is adapted such that the implant ( 10 ) for releasing in the body cavity from the holding surface ( 13 ) is detachable, characterized in that the holding surface ( 13 ) on an outer circumference of the feed element ( 11 ) is formed and the feed element ( 11 ) at least one hollow channel ( 14 ), which extends into the region of the holding surface ( 13 ) and with at least one, in particular with a plurality of openings ( 15 ) connected in the holding surface ( 13 ) are formed, wherein the hollow channel ( 14 ) is connected or connectable to a suction device and / or a pressure device and forms a suction line and / or a pressure line such that the implant ( 10 ) in use with a holding pressure for fixing the implant to the feed element ( 11 ) and / or with a release pressure for releasing the implant can be acted upon. Device according to claim 1, characterized in that side channels ( 16 ), which are arranged radially, the hollow channel ( 14 ) and the openings ( 15 ) connect. Apparatus according to claim 1 or 2, characterized in that the feed element ( 11 ) a peak ( 17 ), which is distal to the support surface (by the user). 13 ) is arranged and designed such that in use a concretion, in particular a thrombus, through the tip ( 17 ) is pressed against the vessel wall and / or a vessel or tissue is puncturable. Device according to claim 3, characterized in that the tip ( 17 ) in longitudinal section two, with respect to the longitudinal axis of the feed element ( 11 ), differently inclined sides, or one to the longitudinal axis of the feed element ( 11 ) parallel page ( 18b ) and a sloping side ( 18a ) or is conical. Device according to at least one of claims 1 to 4, characterized in that the hollow channel ( 14 ) is connected or connectable to a supply device for medicaments and / or liquids in such a way that the hollow channel ( 14 ) forms both a suction and / or pressure line as well as a drug supply and / or fluid supply. Apparatus according to claim 5, characterized in that the hollow channel ( 14 ) has an outlet for drug delivery and / or fluid delivery which at the end ( 12a . 12b ) of the feed element ( 11 ) is provided. Device according to at least one of claims 1 to 6, characterized in that the hollow channel ( 14 ) has at least one valve which the openings ( 15 ) is arranged downstream of the user distally or proximally upstream and in the suction or pressure mode the hollow channel ( 14 ) closes. Device according to at least one of claims 1 to 7, characterized in that the hollow channel ( 14 ) at least one further opening ( 19 ), which at the end ( 12a ) of the feed element ( 11 ) is designed for sucking and holding a concretion, in particular a thrombus. Device according to at least one of claims 1 to 8, characterized in that the feed element ( 11 ) with the holding surface ( 13 ) and at least one first hose-like feed element ( 20a ) are telescopically arranged one inside the other. Apparatus according to claim 9, characterized in that the first feed element ( 20a ) and at least one second hose-like feed element ( 20b ) are telescopically arranged one inside the other. Apparatus according to claim 9 or 10, characterized in that the feed element ( 11 ) with the holding surface ( 13 ) is formed in its length such that a user-proximal end ( 12b ) of the feed element ( 11 ) in the fully extended state by the user is operable. Device according to at least one of claims 1 to 10, characterized in that the feed element ( 11 ) with the holding surface ( 13 ) in a line ( 21 ), in particular in a catheter, is arranged relatively movably, wherein the in the feed element ( 11 ) formed hollow channel ( 14 ) through the line ( 21 ) is connected or connectable to the suction device and / or the pressure device and / or the drug delivery device and / or fluid supply. Arrangement comprising a device according to one of the preceding claims and a medical implant ( 10 ), which in the area of the holding surface ( 13 ) on the feed element ( 11 ) is fixable, wherein the implant ( 10 ) a wall ( 22 ) with at least one holding and / or releasing area ( 23 ) which, in use, has at least one opening ( 15 ) in the holding surface ( 13 ) is covered and with a holding force and / or a release force can be acted upon, which is generated in use by the holding pressure or the release pressure. Arrangement according to claim 13, characterized in that the wall ( 22 ) comprises a rotationally symmetrical, in particular a cylindrical wall, which is rigid or flexible. Arrangement according to claim 13 or 14, characterized in that the wall ( 22 ) by a perforation ( 24 ), wherein the ratio between the material surface and the entire wall surface is more than 20%, in particular more than 30%, in particular more than 40%, in particular more than 50%, in particular more than 60%, in particular more than 70%, in particular more than 80%, in particular more than 90%.

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