Device for draining cerebrospinal fluid

Abstract

The invention relates to a device (1) for draining cerebrospinal fluid, wherein: the device (1) comprises a shaft (2) which can be implanted into a cranial bone (14) of a human or animal; the device (1) is suitable for draining cerebrospinal fluid from the subarachnoid space and / or a cerebral ventricle (15) into the diploe of the cranial bone (14), and the shaft (2) has outlet openings (4) pointing in the radial direction; a valve (17) is arranged in the interior of the shaft (2) and connects a first chamber (21) to a second chamber (22); the second chamber (22) is fluidically connected to the outlet openings (4), and a tube (5) joins the shaft (2) at the distal end face of the shaft (2) or a conduit (20) to which a tube (5) is connected is arranged on the distal end face of the shaft (2); the tube (5), in its proximal portion, or the conduit (20) is fluidically connected to the first chamber (21), and the tube (5) distally has at least one inlet opening (8) for cerebrospinal fluid; the inlet openings (8) can be placed in the subarachnoid space (6) and / or in the region of a cerebral ventricle (15), and the tube (5) has a lumen (9) into which a wire (6) can be introduced; the wire (6), in the introduced state, protrudes from the device (1) at the proximal end face thereof. The invention allows the treating doctor to place and adjust the device (1), according to requirements, in order to conduct the cerebrospinal fluid into the diploe of the cranial bone (14). Placement is possible under local anaesthesia.

Description

[0001] Device for draining cerebrospinal fluid

[0002] The invention relates to a device for draining cerebrospinal fluid, wherein the device has a shaft that can be implanted into a skull bone of a human or animal, wherein the device is suitable for draining cerebrospinal fluid from the subarachnoid space or a brain ventricle into the diploe of the skull bone, and the shaft has radially directed outlet openings, wherein a valve is arranged inside the shaft.

[0003] The bony skull contains not only the brain tissue itself, which makes up about 80% of its volume, but also blood (10%) and cerebrospinal fluid (10%). This fluid is also called cerebrospinal fluid or simply CSF. Cerebrospinal fluid is a nearly clear, colorless fluid produced by ependymal cells in the brain ventricles and by the choroid plexus (a network of blood vessels in the brain ventricles). The brain ventricles are chambers in the brain filled with cerebrospinal fluid. In addition, cerebrospinal fluid surrounds the brain in the subarachnoid space, the space between the arachnoid mater (spider membrane) and the pia mater (the delicate inner meninges). The cerebrospinal fluid protects the brain from pressure damage, as the brain essentially floats in the fluid, and also provides protection for the brain and spinal cord from external shocks.Furthermore, cerebrospinal fluid plays a role in the transport and removal of organic waste. The total volume of the cerebrospinal fluid space is 100 to 160 ml. Between 450 and 600 ml of cerebrospinal fluid are produced daily within the skull. Normal intracranial pressure in a healthy adult is 5 to 15 mmHg. Continuous reabsorption of cerebrospinal fluid is essential to prevent this pressure from rising continuously. This reabsorption occurs through the arachnoid granulations, which are outpouchings of the arachnoid mater through the dura mater (the tough outer membrane surrounding the brain) into the wall of the venous sinus. The cerebrospinal fluid passes through these granulations into the venous sinus and thus into the venous bloodstream.

[0004] When the balance between cerebrospinal fluid (CSF) production and reabsorption is disrupted, a chronic increase in the total CSF volume occurs, a condition known as hydrocephalus. This leads to an increase in intracranial pressure, accompanied by the displacement of parts of the brain towards the foramen magnum, which can ultimately result in death from compression of brain tissue essential for the respiratory and cardiovascular systems. Chronic elevation of intracranial pressure causes irreversible brain damage, particularly visual impairment and even blindness. Hydrocephalus can occur in children and, less frequently, in adults, but is most common in people over 80 years of age. In this age group, the incidence is approximately 400 per 100,000.

[0005] To treat an acute increase in intracranial pressure, cerebrospinal fluid can be drained externally via a ventricular drain. For this procedure, a hole is drilled into the skull, and the drain is inserted into a lateral ventricle. However, such an external ventricular drain must be removed after a few days and replaced with an internal cerebrospinal fluid drainage system, as otherwise an infection within the skull can occur.

[0006] Internal cerebrospinal fluid (CSF) shunts are typically placed from a lateral ventricle into the abdominal cavity or peritoneum (the lining of the abdominal cavity) or into the right atrium of the heart. While creating such a shunt is now routine, revision rates between 30 and 80% are reported in the literature (Kaestner et al., Neurol Neurochir Pol. 2017, 51, 72-76; Stone et al., J Neurosurg Pediatr. 2013, 11, 15-9). Another problem is overdrainage due to a so-called siphon effect. Because the CSF is drained into an area significantly below the brain, a vacuum can form, caused by the suction effect of communicating vessels. Consequently, too much cerebrospinal fluid may be drained, impairing its function.To counteract the siphon effect and overdrainage, cerebrospinal fluid drainage can be controlled via a valve; the drainage rate should be in the range of 10 to 50 ml / h. However, valves can become clogged or malfunction.

[0007] To avoid the siphon effect, drainage of the cerebrospinal fluid without a significant difference in elevation would be desirable. Therefore, alternatives to drainage into the abdominal cavity or a cardiac atrium have already been explored.

[0008] Direct drainage of cerebrospinal fluid into surgically accessible veins has proven problematic, as these are thin-walled and can be damaged by minor manipulations or become blocked by thrombus formation.

[0009] As an alternative, the drainage of excess cerebrospinal fluid into the skeletal system, in which CSF is drained into a bone, has been repeatedly investigated in the past. Various shunts have been examined in this context (see, e.g., Morosanu et al., Neurochirurgie 2022, 68, e84-e96), but so far these procedures have not become established or have presented various problems.

[0010] The diploe is the spongy interior of the skull bone, also commonly referred to as the cancellous bone or simply spongiosa. It lies between the outer and inner layers of the skull. Within the diploe are numerous veins that connect the intracranial and extracranial venous systems. However, the drainage of excess cerebrospinal fluid into the diploe is still in an experimental stage and is the subject of computer models (Nzekwu et al., Comput Methods Biomech Biomed Engineering 2015, 18, 662-675).

[0011] US 2014 / 0276347 A1 describes an intraosseous shunt suitable for draining cerebrospinal fluid into the diploë. This device is essentially a screw-like device inserted into the skull bone, featuring openings into the subarachnoid space and openings that allow cerebrospinal fluid to drain laterally into the diploë. The shunt incorporates an internal valve to regulate flow. However, achieving optimal shunt placement to maintain the desired cerebrospinal fluid flow rate has proven challenging.

[0012] Based on the aforementioned state of the art, the task was therefore to provide a device for draining cerebrospinal fluid that is suitable for draining the fluid into the diploes of the skull bone and can be placed and adjusted according to the requirements of the treating physician.

[0013] This problem is solved according to the invention by a device for draining cerebrospinal fluid, wherein the device has a shaft that can be implanted into a skull bone of a human or animal, wherein the device is suitable for draining cerebrospinal fluid from the subarachnoid space and / or a cerebral ventricle into the diploe of the skull bone, and the shaft has radially extending outlet openings, wherein a valve is arranged inside the shaft which connects a first chamber to a second chamber, wherein the second chamber has a fluid connection with the outlet openings and a tube opens into the shaft at the distal end face of the shaft or a tube is arranged at the distal end face of the shaft to which a tube is connected.wherein the tube in its proximal section or the pipe is in fluid communication with the first chamber and the tube has at least one distal inlet opening for cerebrospinal fluid, wherein the inlet openings can be placed in the subarachnoid space and / or in the region of a cerebral ventricle and the tube has a lumen into which a wire can be inserted, wherein the wire, when inserted, protrudes from the proximal end face of the device.

[0014] In the invention, cerebrospinal fluid is introduced into the shaft of the device via a tube. The distal end of the tube opens into the subarachnoid space or a cerebral ventricle. Here, the tube has at least one, but preferably several, inlet openings through which the fluid can enter the tube. The fluid is directed proximally, where the tube is in direct or indirect fluid communication with the first chamber. Subsequently, the fluid passes through the valve into the second chamber, which in turn has a fluid communication with the radially directed outlet openings. Finally, the fluid flows radially through the outlet openings into the diploes of the skull bone.

[0015] The use of a flexible tube ensures that the brain, into which the tube connects, is not damaged. The tube has a lumen into which a wire can be inserted. This may be the same lumen used for draining the fluid, but a separate, additional lumen is also conceivable, for example, for continuous pressure measurement. The wire is typically only needed during the initial placement of the device, particularly the tube, and is subsequently removed.

[0016] Once the wire is inserted into the lumen of the tube, it protrudes from the proximal end of the device. The treating physician can then grasp the wire and position the distal end of the tube as desired. In particular, the wire allows the physician to control the tube, for example, by inserting it more or less deeply into the subarachnoid space or a cerebral ventricle, or by rotating it. The wire can thus serve as a stabilizing guide wire, if necessary. The tube is preferably designed to conform to a certain degree of curvature without kinking so severely that fluid drainage is impaired. Once the tube is correctly positioned, the wire is withdrawn proximally from the lumen and removed. If necessary, the tube can be shortened to the desired length. A typical tube length is between 50 and 150 mm.In one embodiment, the hose is then fixed within the shaft. This can be achieved, for example, by inserting a hose clamp into the proximal end of the hose. In this context, the proximal end of the device is also closed, so that the discharged fluid is guided through the hose into the first chamber, from there through the valve into the second chamber, and finally out of the radial outlet openings.

[0017] According to an alternative embodiment, a short tube or a plug with an internal cavity is arranged in the shaft, to which the hose is connected. The tube can be designed distally to ensure a secure connection with the hose, for example, in the form of a hose barb. The tube can project distally beyond the shaft itself, typically by a few millimeters. This facilitates the connection with the hose compared to the previously described variant, in which the hose must be inserted into the shaft and connected there. In this embodiment, the hose is not directly connected to the first chamber, but indirectly via the tube. Accordingly, the tube must have a fluid connection to the first chamber by means of suitable openings.

[0018] The pipe and hose can also be designed as a single unit. According to this embodiment, the device can be inserted into the skull bone by first drilling a hole in the skull bone, then inserting the shaft into the hole, and finally inserting the component supporting the pipe, along with the hose, into the shaft. If necessary, the shaft is then closed proximally or fitted with additional components. Alternatively, the hose can also be inserted into the hole as a single unit within the overall device. In particular, it is also possible to use a hose adapter that can be inserted into the shaft and locks into place. Such a hose adapter can be designed similarly to a compressed air coupling for pressure hose connections. For example,A short metal tube is inserted into the distal section of the hose so that the hose can be radially clamped within the hose adapter. Clamping rings or pliers can be provided inside the hose adapter for this purpose. This system makes inserting and securing the hose particularly easy. The hose adapter can then be inserted into the distal end of the shaft, where it clicks into place. This can be achieved using locking lugs known from prior art. It is therefore a hose adapter with a click-lock function. Advantageously, the hose adapter has a cylindrical shape. Hose adapters that can be fixed in the shaft in other ways, e.g., by screwing them in, are also conceivable.

[0019] To provide more space for the valve inside the shaft, the opening of the hose or the arrangement of the tube on the distal end face of the shaft can be located off-center, i.e., eccentrically. This is particularly relevant when the valve is perpendicular to the longitudinal axis of the shaft. The off-center arrangement of the tube / hose allows the valve itself to be larger. This is advantageous for enabling the valve to open or close within the desired pressure range.

[0020] Typically, a seal is provided in the distal region of the shaft or device. This seal is embedded in the distal end of the shaft and has a passage for the hose and / or tube for connecting the hose. The seal can be secured with an additional cap or screw.

[0021] The valve between the first and second chambers allows cerebrospinal fluid to drain from the device while preventing backflow of blood from the diploi into the subarachnoid space or a cerebral ventricle. The stem can be positioned by drilling a hole in the skull and screwing it in. The stem can be designed as a screw body with an external thread. Drilling the hole should be done carefully, avoiding heat generation, for example, using a hand drill and tap. This can be done under local anesthesia. Atraumatic and precise insertion of the screw body is crucial.

[0022] The length of the shaft and the external thread running along it are matched to the thickness of the skull bone so that the device is securely held in the skull bone, particularly in the outer and inner tabula, without protruding excessively in either the proximal or distal direction. Furthermore, the outlet openings are positioned so that they open into the diploes, i.e., approximately centrally in the axial direction. Advantageously, the outlet openings open radially in different directions and are preferably arranged radially around the entire device. Manufacturing the shaft can be simplified by using a disc-shaped cap at the distal end.

[0023] The outlet openings can have different shapes. For example, they can be grooves cut into the shaft. These can run longitudinally along the shaft, perpendicular to it, or diagonally to it. Combinations of these shapes are also possible. The grooves can extend to the distal end of the shaft or end before it. Circumferential indentations in the shaft are also possible. Other outlet opening shapes are conceivable, such as circular or oval openings. The crucial factor is that the cerebrospinal fluid can pass through the outlet openings without difficulty.

[0024] According to the invention, screwing the shaft into the skull bone to create a positive-locking connection is preferred. However, other methods for fixing the shaft in a designated opening in the skull bone are not excluded. For example, a friction-locking connection by inserting the shaft or a material-locking connection by gluing or using bone cement would be conceivable. The invention includes all methods of fixing the shaft in the skull bone and any joining techniques, in particular positive-locking, material-locking, and friction-locking connections, provided they are compatible with the intended use from a medical perspective.

[0025] According to the invention, axial means the direction corresponding to or parallel to the axis in which the shaft or screw body is inserted or screwed in, while radial means the direction orthogonal to this axis. The cerebrospinal fluid thus exits radially into the diploa, while the device is inserted axially into the skull bone. From the diploa, the fluid can be drained via the venous system. In this context, proximal means towards the outside of the body, i.e., towards the treating physician, and distal means towards the inside of the body, i.e., away from the treating physician. In other words, the distal end of the device points towards the brain, while the proximal end points outwards. The longitudinal direction is understood to be the direction from proximal to distal; the longitudinal axis of the shaft runs accordingly through the center of the shaft. The longitudinal direction therefore corresponds to the axial direction.

[0026] Preferably, the hose can be moved longitudinally within the shaft using the wire. This allows for control of the hose's position relative to the shaft and the rest of the device. The longitudinal mobility of the hose refers to the situation before the hose is finally fixed in or to the device. However, adjustments can also be made afterward, for example, if the initial hose placement proves to be suboptimal. In this case, the hose is released, the wire is reinserted to correct the hose's position, and then the wire is removed and the hose is re-fixed.

[0027] Ideally, the inlet openings of the tube should be radially oriented, meaning the cerebrospinal fluid (CSF) inlets are located laterally. This allows fluid to enter the tube from all sides. Having multiple openings reduces the risk of CSF drainage being impaired by the blockage of individual inlets. The inlet openings can also be positioned axially at different locations, for example, more proximally and more distally. The more proximally located inlets can be used for draining CSF from the subarachnoid space, while the more distal inlets can be used for draining CSF from a cerebral ventricle.

[0028] To protect brain tissue and prevent axial obstruction, the distal end of the tube should ideally be closed. This facilitates guidance using the wire, which can be inserted into the tube to its end. When the wire is in contact with the closed end of the tube, it can be easily advanced over the wire. This also simplifies lateral control of the tube.

[0029] In the case of a direct connection, the fluid connection between the hose and the first chamber of the device can be established by providing radially oriented openings in the hose's proximal region. The fluid that has entered the hose distally exits laterally proximally and enters the first chamber, from where it passes through the valve into the second chamber and finally exits through the outlet openings. Providing lateral, i.e., radially oriented, openings is also advantageous because it allows the hose to be axially fixed and sealed at its proximal end, for example, by inserting a hose barb, connecting it to a sealing head, and attaching a cap.

[0030] If the fluid connection between the hose and the first chamber is indirect, namely via a tube that connects the hose to the shaft, this tube can sensibly have radially oriented openings to establish a fluid connection with the first chamber. The cerebrospinal fluid then flows from the hose into the tube and from there into the first chamber. The further transfer of the fluid from the first chamber through the valve into the second chamber corresponds to the embodiment in which the fluid flows directly from the hose into the first chamber.

[0031] To make the wire easier to handle, it is advisable to provide a grip at the proximal end. This allows the user to pull the wire back and forth and also rotate it without needing an additional tool such as pliers. The grip can be designed in various ways; one option is to provide an easy-to-grip ring. Other possibilities include thickened sections, grip plates attached to the wire, or similar features.

[0032] The proximal end of the device can be made of an elastic material, similar to a septum as used in vials. This allows the wire to pass through while simultaneously ensuring that the opening for the wire closes automatically after its removal, thus sealing the device proximally. Alternatively, an additional method for closing the proximal opening for the wire can be provided, for example, with a removable or insertable cover. The proximal end of the device can also be formed by a cap. Suitable materials for the proximal end include silicone or PTFE (polytetrafluoroethylene). Creating a puncture opening is also useful for taking samples or performing measurements when necessary.The advantage of using a material like silicone or PTFE is that it self-seals even after puncture, remaining cerebrospinal fluid (CSF)-tight. Furthermore, the material adheres well to the skull. To allow for easy removal of the cap, it may have features such as grooves for a wrench. A sealing head, made of a hard plastic, can be positioned between the cap and the shaft to seal the proximal end of the tube, although this is not strictly necessary due to the self-sealing mechanism. A valve and / or ports for measuring instruments can also be integrated into the proximal end of the device. This allows, for example, pressure measurements to monitor the effectiveness of the hydrocephalus treatment and CSF drainage. CSF can also be withdrawn or medications administered as needed.

[0033] Furthermore, it is possible to equip the proximal end of the device with a reservoir, similar to a Rickham or Ommaya reservoir. This reservoir can be designed so that it can be punctured with a cannula to withdraw fluid. Accordingly, the reservoir should have an external membrane or septum for puncture, e.g., made of silicone, when implanted. Drugs or diagnostic agents can also be administered via the reservoir if necessary.

[0034] Preferably, the first and / or the second chamber are designed as radially circumferential chambers; more preferably, both the first and the second chamber are designed as such. Accordingly, the first chamber forms a radially circumferential inner chamber, and the second chamber a radially circumferential outer chamber. Providing radially circumferential chambers has the advantage that the cerebrospinal fluid to be drained can enter the inner chamber through various openings from the hose or tube and flow from the outer chamber into the diploe through various outlet openings. It is advantageous to have several openings for the different fluid transitions, as this compensates for the potential clogging of individual openings.In the context of the inner and outer chambers, "radially circumferential" means that the chambers each extend at least over a part of the circumference of the device; a complete ring formation by the chambers is not absolutely necessary.

[0035] The use of an umbrella-style check valve has proven advantageous. This is a structurally simple valve consisting of a pin and a shield made of an elastic material attached to the pin. The pin protrudes through the surface with the openings through which the fluid is intended to flow in one direction. When the fluid flows in the desired direction with sufficiently high pressure, the shield lifts slightly from the surface, opening the openings. Conversely, when the fluid flows in the opposite, undesired direction, the shield adheres to the surface and is further pressed against it by the fluid flow. This prevents the ingress of fluid, such as blood from the diploe, into the device according to the invention. Common, medically suitable elastomers can be used as the elastic material, for example, silicone, fluorosilicone, or suitable types of rubber.The use of an umbrella-type check valve is particularly advantageous because its simple design ensures continuous operation without intermediate maintenance, and clogging of the valve is generally not to be expected despite the components and cells contained in the cerebrospinal fluid.

[0036] However, other valves are also conceivable, such as a duckbill valve or a valve based on a spring mechanism. Regardless of the type of valve, it should be set to open at the pressures typically caused by the cerebrospinal fluid, while simultaneously ensuring that the CSF outflow is not excessive. A typical setting is a valve that opens at a pressure or pressure differential of 15 ± 5 mbar (in the desired fluid direction). It is also possible to set the valve to open at a pressure differential of 20 to 28 mbar, particularly around 25 mbar, in the direction of flow. At a pressure differential of less than approximately 10 mbar, the valve may close automatically.

[0037] The valve can be positioned orthogonally to the longitudinal direction, thus creating a connection between the first, inner chamber and the second, outer chamber. This provides sufficient space to the side of the valve for the tube and the wire, enabling correct placement of the tube in the subarachnoid space or a cerebral ventricle. As mentioned previously, this space can be further increased if the wire is passed eccentrically through the shaft rather than centrally, thus providing more room for the valve itself and allowing for the selection of a larger valve if necessary.

[0038] In the case of a valve arranged orthogonally to the longitudinal direction, the valve can be recessed into the screw body in the area of ​​the thread, provided a corresponding receptacle for the valve is provided there. To seal the second chamber (outer chamber) adjoining the valve from the outside, a sealing cap can be provided at this point, sealing the receptacle to the outside.

[0039] Instead of arranging the valve orthogonally to the longitudinal direction, arranging it longitudinally is also fundamentally possible. However, in this case as well, it must be ensured that the wire can run longitudinally through the shaft. This can be achieved, in particular, by using a valve that allows the wire to pass through in addition to regulating the fluid. Specifically, the valve can have a self-closing passage for the wire.

[0040] A duckbill valve, also known as a beak or duckbill valve, is suitable here, and it preferably has a continuous rim. The flaps or sails of the duckbill valve point distally, allowing the wire to be advanced through the valve from the proximal end to the distal end, thus enabling control of the device. Once the tubing is correctly positioned, the wire can be withdrawn and the valve closes automatically.

[0041] On the other hand, the rim located at the proximal end of the duckbill valve allows cerebrospinal fluid to flow from the first to the second chamber. When the valve is closed, the rim of the valve, made of an elastic material, rests on, for example, a perforated disc, with the perforations designed to allow the fluid to pass through. As soon as the fluid pressure exceeds a certain threshold, the rim lifts slightly, and the fluid can pass through and enter the second chamber. The duckbill valve can be inserted into the first chamber, which may be formed, for example, by a cylindrical or cup-shaped object, the proximal end of which may be formed by the perforated disc.

[0042] According to a particularly preferred embodiment, a port is arranged at the proximal end section of the device. This port has a fluid connection to the second chamber and allows cerebrospinal fluid to be drained to the outside. This port can be oriented radially or axially, with the radial direction being preferred. Preferably, the port has a closure mechanism. This additional drainage option allows cerebrospinal fluid to be drained as needed if the intended drainage into the diploë proves insufficient, for example, at the beginning of treatment when high intracranial pressure has already developed. Simultaneously, the amount of cerebrospinal fluid drained can be measured in this way. This amount can be up to 500 ml per day.Should the flow rate prove to be too high or too low, the device can be readjusted by repositioning the tube. Once the cerebrospinal fluid drainage is optimally adjusted, the additional drainage option can be deactivated, allowing further cerebrospinal fluid drainage to occur into the diplois of the skull bone as described above.

[0043] The additional connection at the proximal end of the device can be designed as a tubular handpiece. In particular, such an additional connection can also be combined with a proximal end that incorporates a reservoir similar to a Rickham or Ommaya reservoir, thus eliminating the need to puncture the reservoir with a cannula. In this case, fluid is supplied or drained via the connection.

[0044] It is possible to attach the additional port to the proximal end section, or to equip the latter with a port from the outset. The proximal end section can therefore be designed as a single piece or in multiple parts. For draining cerebrospinal fluid via the additional port, a longitudinally arranged valve as described above has proven advantageous because it is able to expel any residual air in the proximal region of the shaft more quickly, which would otherwise impede drainage.

[0045] The diameter of the device according to the invention is typically approximately 10 to 18 mm, with the thread, in the case of a screw body, having an outer diameter of, for example, 10 to 14 mm. The thread length should be appropriate to the thickness of the skull and can be approximately 8 to 14 mm. A diameter of 0.8 to 1.2 mm, preferably 1.0 mm, has proven suitable for the entry and exit openings.

[0046] In addition to the device according to the invention, the invention also relates to a method for draining cerebrospinal fluid, in which an opening, typically a bore, is made in the skull bone and a device according to the invention is used to drain the cerebrospinal fluid into the diploes. The description provided applies accordingly to the method according to the invention. The device according to the invention can be inserted under local anesthesia using a hand drill as a self-contained system.

[0047] All descriptions of features of the invention refer to all embodiments, unless otherwise indicated by the context.

[0048] The invention is explained in more detail by way of example with reference to the embodiments illustrated in the figures. It should be noted that the figures show preferred embodiments of the invention; however, the invention is not limited to these. In general, the invention encompasses, insofar as it is technically feasible, any combination of the technical features listed in the claims or described in the description as relevant to the invention.

[0049] Figure 1 shows the device according to the invention;

[0050] Fig. 2 shows the device according to the invention.

[0051] Fig. 1 implanted in the skull bone;

[0052] Fig. 3 shows another variant of the device according to the invention;

[0053] Fig. 4 the device according to the invention in

[0054] Longitudinal section;

[0055] Fig. 5 the device according to the invention in

[0056] Longitudinal section without wire;

[0057] Fig. 6 shows the device according to the invention.

[0058] Fig. 5 in longitudinal section, rotated 90°;

[0059] Fig. 7 shows an alternative embodiment of the device according to the invention in longitudinal section;

[0060] Fig. 8 shows a side view of the device according to the invention from Fig. 7;

[0061] Fig. 9 shows an oblique view of the device according to the invention from Fig. 7;

[0062] Fig. 10 shows the device according to the invention.

[0063] Fig. 7 in longitudinal section, rotated 90°;

[0064] Fig. 11 shows an alternative embodiment of the device according to the invention in longitudinal section;

[0065] Fig. 12 shows a hose adapter for securing the

[0066] Hose in the shaft;

[0067] Fig. 13 shows a longitudinally arranged

[0068] Duckbill valve in exploded view; Fig. 14 shows a longitudinally arranged one

[0069] Duckbill valve in longitudinal section;

[0070] Fig. 15 shows the device according to the invention in one embodiment.

[0071] exploded view and

[0072] Fig. 16 shows the device according to the invention.

[0073] Fig. 15 in longitudinal section.

[0074] Fig. 1 shows an oblique view of the device 1 according to the invention. This device has a shaft 2 with a thread 3 for screwing into the skull bone. A tube 5 enters the distal end of the shaft 2, and inlet openings 8 for the cerebrospinal fluid are located at the distal end of this tube. The fluid flows through the tube 5 in a proximal direction (obliquely upwards in the illustration) to enter the shaft 2 of the device 1 and be drained there through the outlet openings 4 into the diploes.

[0075] Proximal to the shaft 2, the device has a proximal end section 10 made of an elastic material such as silicone, with a total of three access points 13 provided for removing the proximal end section 10 using a wrench. Furthermore, a port 11 is located in the region of the proximal end section 10, through which cerebrospinal fluid can be drained externally. This is particularly useful if the intended drainage into the diploë is insufficient, or at the beginning of treatment when high intracranial pressure has already developed and needs to be reduced quickly. The port 11 also provides a means of pressure measurement without having to completely remove the end section 10. The proximal end section 10 is thus comparable to a Rickham cap. The port 11 can be used as a separate element within the end section 10, for example.The device 1 may be made of a hard plastic or, as a component of the end section itself, of an elastic material. A tube can be attached to the connection 11. In Fig. 2, the device 1 from Fig. 1 is shown together with the brain 16, with the device 1 being implanted in a skull bone 14, which is only shown schematically. In this case, the tube 5 of the device 1 extends into a cerebral ventricle 15. There, cerebrospinal fluid can enter the tube 5 through the inlet openings 8 and be drained via the device 1 or its outlet openings 4 into the diploes of the skull bone 14.

[0076] Fig. 3 shows another device 1 according to the invention, which is basically identical in construction to the device from Fig. 1, but has a shorter tube 5. The tube 5 can also be adjusted to the desired length by the physician as needed. A comparatively short tube 5 serves to drain cerebrospinal fluid from the subarachnoid space.

[0077] Fig. 4 shows a longitudinal section through the device 1 according to the invention. The tube 5 has an inner lumen 9 that is closed at the distal end but has distal lateral inlet openings 8 for receiving cerebrospinal fluid. During placement of the tube 5, a wire 6 runs through it, which is used to position the tube 5 as desired. For easier handling, the wire 6 has a proximal grip 7, here in the form of a ring. After correct placement of the tube 5, the wire 6 can be removed. The tube 5 is attached to a tube olive 12 located inside the shaft 2. The shaft 2 has a thread 3, which allows the device 1 to be screwed into the skull bone.

[0078] The flow of cerebrospinal fluid is represented by the arrows. It enters at the inlet openings 8 at the distal end of the tube 5, flows proximally into the shaft 2 of the device 1 into a first chamber, passes through a valve into a second chamber, and from there through the outlet openings 4 to the outside into the diploe. An additional connection 11 is provided in the region of the proximal end section 10.

[0079] In Fig. 5, the device 1 according to the invention is also shown in longitudinal section, but after placement, i.e., the wire 6 has already been removed. Furthermore, compared to the device 1 shown in Fig. 4, the device 1 has a significantly longer tube 5, which thus extends into deeper cerebral ventricles. The cerebrospinal fluid again enters through the inlet openings 8 and passes through the lumen 9 of the tube 5 into the interior of the shaft 2. There, it passes via the valve 17 from the first to the second chamber inside the shaft and finally exits through the outlet openings 4 into the diploe. In addition, a distal seal 18 for sealing the tube 5 in the distal direction and a sealing head 19 made of a hard plastic, which provides a seal in the proximal direction, are visible.Additionally, the connection 11 is shown in the area of ​​the proximal end section 10, through which an excess of cerebrospinal fluid can be drained if necessary.

[0080] In Fig. 6, the device 1 according to the invention from Fig. 5 is again shown in longitudinal section, but rotated by 90°. Accordingly, the valve 17 is not visible here; cerebrospinal fluid exits through the outlet openings 4 on the left and right.

[0081] Figure 7 shows a longitudinal section of the device 1 according to the alternative embodiment, in which the hose 5 does not open into the shaft 2 at its distal end face, but rather a tube 20 is arranged at the distal end face of the shaft 2, to which the hose 5 is connected. This tube 20 projects slightly beyond the distal end face of the shaft 2, which simplifies the connection of the hose 5. At its distal end, the tube 20 has a connection in the form of a hose barb, onto which the hose 5 can be attached. The tube 20 is connected to the first chamber in such a way that the cerebrospinal fluid can enter the first chamber. From there, as in the other embodiments, the fluid passes through a valve 17 into the second chamber and finally reaches the outlet openings 4.

[0082] The tube 5 itself has several inlet openings 8 at its distal end through which cerebrospinal fluid can enter the lumen 9 of the tube 5. A wire 6 (not shown) can be guided through this lumen 9 to position the tube 5 appropriately. Otherwise, the construction of the device 1 largely corresponds to that shown in Fig. 4; the difference lies in the connection between the tube 5 and the shaft 2.

[0083] Figure 8 shows a side view of the device 1 from Figure 7. The inlet openings 8 are visible, through which the cerebrospinal fluid enters the tube 5, from there the pipe 20, and finally passes through the chambers and the valve in the shaft 2 to the outlet openings 4. Proximally, the device 1 has a proximal end section 10, which has a connection 11 for the additional drainage of cerebrospinal fluid as needed. Furthermore, the proximal end section 10 has engagement points 13 to allow the end section 10 to be removed if necessary.

[0084] Fig. 9 shows the same device as Fig. 8 in an oblique view. It is particularly evident how the hose 5 is attached to the pipe 20.

[0085] Fig. 10 also shows the device from Fig. 7 in longitudinal section, but rotated 90° relative to that figure. Accordingly, the valve 17 is not visible here, but various outlet openings 4 at different positions on the shaft 2 are.

[0086] Fig. 11 shows a longitudinal section of a device 1 according to the invention in an embodiment in which the hose 5 opens off-center into the first chamber 21 of the shaft 2. This leaves correspondingly more space for the valve 17, which regulates the flow of cerebrospinal fluid from the first chamber 21 to the second chamber 22.

[0087] Figure 12 shows a hose adapter 23. A short metal tube 24 is inserted into the proximal end of the hose 5, thereby clamping the hose 5 in the hose adapter 23. Furthermore, the hose adapter 23 has a locking projection 25 for fixing it in the shaft 2 of the device 1.

[0088] Fig. 13 shows a valve 17 in the form of a duckbill valve. This is inserted longitudinally into the shaft 2, which is why two valve functions are necessary to ensure, on the one hand, the flow of cerebrospinal fluid and, on the other hand, the passage of a wire 6. The valve 17 has two flaps (sails) 26, which are slightly pushed to the side when a wire 6 is inserted from the proximal side (here, from above). When the wire 6 is removed after the tube 5 has been correctly positioned, the flaps 26 close again and the valve 17 is closed longitudinally.

[0089] Furthermore, the valve 17 has an additional valve function due to its circumferential rim 27. This rim rests on a disc 28 provided with openings 29. When cerebrospinal fluid (CSF) reaches the valve 17 through the openings 29 and the pressure exceeds a certain threshold, the circumferential rim 27 lifts slightly from the disc 28, creating a gap through which CSF can enter the second chamber 22.

[0090] Fig. 14 shows the valve 17 from Fig. 13 in the assembled state.

[0091] Figure 15 shows an exploded view of the device 1 according to an embodiment with a longitudinally inserted duckbill valve 17. This valve is located in a cup-shaped object 31. The connection of the tube 5 is made via a tube adapter 23; the distal end of the shaft 2 is formed by a disc-shaped cover 30. The shaft 2 has several outlet openings 4 in the form of radially extending indentations in the shaft 2. In the proximal region, i.e., the area ultimately located on the outside of the skull, there is a proximal end section 10 and a port 11 to allow for the additional drainage of excess cerebrospinal fluid if necessary. As long as this bypass is not required, the port can be closed with a plug 33. A seal 32 is also visible.

[0092] Fig. 16 finally shows the device 1 according to Fig. 15 in the assembled state.

Claims

Patent claims 1. Device for draining cerebrospinal fluid, wherein the device (1) has a shaft (2) that can be implanted into a skull bone (14) of a human or animal, wherein the device (1) is suitable for draining cerebrospinal fluid from the subarachnoid space and / or a cerebral ventricle (15) into the diploe of the skull bone (14), and the shaft (2) has radially extending outlet openings (4), wherein a valve (17) is arranged inside the shaft (2), characterized in that the valve (17) connects a first chamber (21) to a second chamber (22), wherein the second chamber (22) has a fluid connection with the outlet openings (4) and a tube (5) opens into the shaft (2) at the distal end face of the shaft (2) or a pipe (20) is arranged at the distal end face of the shaft (2). to which a hose (5) is connected,wherein the tube (5) in its proximal section or the pipe (20) is in fluid communication with the first chamber (21) and the tube (5) has at least one distal inlet opening (8) for cerebrospinal fluid, wherein the inlet openings (8) can be placed in the subarachnoid space and / or in the region of a cerebral ventricle (15) and the tube (5) has a lumen (9) into which a wire (6) can be inserted, wherein the wire (6) protrudes from the proximal end face of the device (1) when inserted.

2. Device according to claim 1, characterized in that the shaft (2) is a screw body with an external thread (3).

3. Device according to claim 1 or 2, characterized in that the hose (5) is movable in the longitudinal direction in the shaft (2) by means of the wire (6).

4. Device according to one of claims 1 to 3, characterized in that the inlet openings (8) of the hose (5) point in a radial direction.

5. Device according to claim 4, characterized in that the inlet openings (8) of the hose (5) are distributed over the length of the hose (5) at different axial positions.

6. Device according to claim 4 or 5, characterized in that the distal end of the tube (5) is closed in the axial direction.

7. Device according to one of claims 1 to 6, characterized in that the hose (5) has openings proximally pointing in a radial direction for establishing a fluid connection with the first chamber (21 ).

8. Device according to one of claims 1 to 6, characterized in that the tube (20) has radially directed openings for establishing a fluid connection with the first chamber (21).

9. Device according to one of claims 1 to 8, characterized in that the wire (6) has a gripping device (7) at its proximal end, which allows the user to move the wire (6) forward and backward and to rotate it.

10. Device according to one of claims 1 to 9, characterized in that the proximal end section (10) of the device (1 ) is formed from an elastic material.

11. Device according to one of claims 1 to 10, characterized in that the first chamber (21 ) is designed as a radially circumferential inner chamber and / or the second chamber (22) is designed as a radially circumferential outer chamber.

12. Device according to one of claims 1 to 11, characterized in that the hose (5) opens off-center into the shaft (2) at the distal end face of the shaft (2) or the tube (20) is arranged off-center at the distal end face of the shaft (2).

13. Device according to one of claims 1 to 12, characterized in that the valve (17) is an umbrella check valve.

14. Device according to one of claims 1 to 12, characterized in that the valve (17) is arranged longitudinally in the shaft (2) and has a self-closing passage for the wire (6).

15. Device according to one of claims 1 to 14, characterized in that a connection (11) is arranged at the proximal end section (10) of the device (1) which has a fluid connection with the second chamber (22) and can be drained externally via the cerebrospinal fluid.

16. Device according to one of claims 1 to 15, characterized in that the proximal end section (10) of the device (1 ) has a reservoir.

17. Device according to one of claims 1 to 16, characterized in that the hose (5) can be fixed in a hose adapter (23), wherein the hose adapter (23) can be inserted into the shaft (2) in a snap-in manner.

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