Rolling membrane catheter with inflation tube

Abstract

The invention relates to a catheter comprising an outer shaft and an inner shaft wherein the inner shaft is arranged at least partially within the outer shaft. The catheter also includes an expandable element including an expandable volume surrounding the inner lumen. The expandable element includes at least two proximal ends connected to the inner shaft and at least one distal end connected to the outer shaft.

Description

Background Art

[0001] The living environment of many people in modern society (e.g., changed nutritional habits, increased exposure to stressful situations, etc.) has led to an increase in coronary artery disease, which is accompanied by an increasing number of catheter-based interventions to facilitate ideal early diagnosis of this disease and / or to curatively address the disease (e.g., through stent implantation).

[0002] One type of catheter is a catheter with a rolling membrane. A rolling membrane can be understood as a hose-like flexible and tubular element, in which one end of the element (e.g., the distal end as seen in the unfolded state) is at least partially folded into itself. Thus, for example, an inner lumen can be formed that can extend from the proximal side of the rolling membrane catheter to the distal end of the rolling membrane catheter. For example, due to the filling of the fluid into the rolling membrane catheter from the proximal side of the catheter, the rolling membrane can be at least partially unfolded, i.e. spread out along the axis of the catheter in, for example, the distal direction. Due to its flexible properties, the rolling membrane can be able to roll out along the axis of the blood vessel, and due to its rolling motion, can reach even branched and / or thin arteries. Due to its unfolding, the rolling membrane can spread along the vessel wall in a rolling manner (e.g., minimizing friction with the vessel wall).

[0003] However, these catheters generally have the disadvantage that the distal portion of the catheter may not maintain a stable shape in all cases, and in particular, the inner shaft to which the rolling membrane may be connected may tend to kink (e.g. in curved and / or narrowed and / or partially occluded arterial sections). Kinking may then adversely affect the properties of the catheter, such that, for example, a potential inner lumen (which may, for example, be used to deliver medical drugs and / or medical devices) may be blocked, such that the corresponding drug and / or medical device may no longer be delivered to the area of ​​interest.

[0004] The risk of catheter kinking can be at least partially avoided by providing a stable inner tube or shaft for the corresponding catheter, thereby providing the catheter with additional kink resistance. Additional kink resistance can be provided, for example, by using a coil that can be wound around the corresponding part of the catheter. Additionally or alternatively, braids, filaments, etc. can also be used in the inner lumen. However, in some cases, such catheters may become too hard for certain applications. In addition, providing the catheter with additional kink resistance may also adversely affect the manufacturing cost of the corresponding catheter.

[0005] Additionally or alternatively, a catheter with improved kink resistance may be provided by increasing the wall thickness of the catheter. However, due to the increased wall thickness of the catheter, the catheter may also be unable to enter the patient's stenotic blood vessels and may therefore be unsuitable for certain applications (e.g., if a stenotic blood vessel needs to be studied).

[0006] Therefore, there is a need to further improve existing catheters so that catheter-based medical interventions can be further simplified and their application range can be expanded. Summary of the invention

[0007] Thus, a catheter is described that includes an inner shaft, a rolling membrane and an expandable element and optionally an outer shaft, wherein the expandable element includes at least two proximal ends connected to the inner shaft. The expandable element may include an expandable volume. The inner shaft may include an inner shaft lumen.

[0008] In a first embodiment, a catheter is described, comprising an outer shaft, an inner shaft, a rolling membrane, and an expandable element comprising an expandable volume; wherein the inner shaft comprises an inner shaft lumen, and the inner shaft is at least partially arranged within the outer shaft, and the rolling membrane is connected to the outer shaft; and wherein the expandable element comprises at least two proximal ends connected to the inner shaft and at least one distal end connected to the rolling membrane.

[0009] In a second embodiment, a catheter is described that includes an inner shaft, a rolling membrane, an expandable element including an expandable volume, and no outer shaft, wherein the inner shaft includes an inner shaft lumen, and the inner shaft is surrounded by the rolling membrane, and wherein the expandable element includes at least two proximal ends connected to the inner shaft and at least one distal end connected to the rolling membrane.

[0010] This can allow the catheter to have an additional and adjustable stabilizing element, i.e., an expandable element. When the catheter is inserted and / or pushed along the patient's blood vessel, the expandable element can, for example, be adapted to be in a non-expanded state so as to provide maximum flexibility. Once the device is positioned at a desired position in the patient's body (e.g., within the patient's blood vessel), it can then be transformed into an expanded state. The inner shaft lumen can be used to deliver additional interventional devices. When expanded, the expandable element can provide additional kink resistance for the catheter because the expandable volume of the expandable element (e.g., fluid-filled) can offset any deformation forces acting on the expandable element. Therefore, the risk of blocking the inner shaft lumen, for example, due to kinking of the catheter, can be suppressed, and the clearly defined diameter of the inner shaft lumen can be ensured in a cost-effective manner, because no coils, etc. are required to stabilize, for example, the inner shaft lumen. In addition, the catheter can provide the required stability without excessive wall thickness, so that it can, for example, be provided as four French products.

[0011] The (operable) connection may be provided as a direct connection, for example. However, an operable connection may mean that the expandable element may move when the inner shaft or the outer shaft moves.

[0012] In some embodiments, it may be sufficient if the expandable member is generally connected to the inner shaft and the outer shaft, but need not necessarily be connected to at least two proximal ends of the inner shaft and to at least one distal end of the outer shaft.

[0013] In some embodiments, the inner shaft may be concentrically disposed within the outer shaft.

[0014] At least partial arrangement of the inner shaft within the outer shaft can be understood as arranging the inner shaft within the outer shaft so that at least the proximal portion of the inner shaft is located within the outer shaft. In some cases, at least the distal (end) portion of the inner shaft can be adapted to be located outside the outer shaft (in the distal direction).

[0015] The rolling membrane and / or the expandable element can be made of a biocompatible material, preferably a thermoplastic material, such as an (organic) thermoplastic polymer or a thermoplastic elastomer (which can also be used, for example, for balloons used in angioplasty). The rolling membrane and / or the expandable element can be made of a pressure-resistant and / or bendable and / or extensible material, which can be a material (or material combination) selected, for example, from polyamide, polyurethane, poly(dodecane-12-lactam), polyether block amide or thermoplastic polyurethane or a mixture thereof.

[0016] The outer shaft and / or the inner shaft may be made of a biocompatible material, preferably a polymer, a reinforced polymer or alternatively a metal or a metal alloy. The material of the outer shaft and / or the inner shaft may have a higher stiffness than the material of the rolling membrane and / or the expandable element. Preferably, the material made of the outer shaft and the inner shaft may each have a higher stiffness than the material made of the rolling membrane and the expandable element. The material made of the outer shaft and the material made of the inner shaft may each have a higher wall thickness than the material made of the rolling membrane and the expandable element.

[0017] The expandable element may extend, at least when expanded, along the longitudinal axis of the catheter by 20 cm to 40 cm, preferably by 26 cm to 35 cm.

[0018] In some cases, the expandable element can be adapted such that its extension along the longitudinal axis exceeds the radial extension of the expansion element when expanded.

[0019] The extension of the expandable element when expanded can allow a compact catheter design in the initial non-expanded state of the expandable element (e.g., relative to the radius of the catheter), so that simple movement of the catheter to the area of ​​interest in the patient's blood vessel can be facilitated (e.g., with minimized friction). The forward movement of the catheter along the axis of the patient's blood vessel (e.g., in the distal direction) can be simultaneously unrestricted by the large outer radius of the catheter. In other words, at the beginning of the catheter-based treatment, the expandable element and / or the inner shaft and / or the outer shaft can be curled to the smallest possible diameter (e.g., by evacuating the internal volume of the expandable element) and can be expanded only when the desired area of ​​interest is reached. In addition, the extension of the expandable element by 20 cm to 40 cm can also allow the catheter to be stabilized in a relatively large portion of the catheter, so that, for example, at least 50%, at least 70%, or substantially 100% of the catheter length can be stabilized.

[0020] More specifically, the extension along the longitudinal axis may be at least two, three, four, five, six, seven, eight, nine or ten times the extension of the catheter in the radial direction (in the expanded state). It is further emphasized that the longitudinal extension may exceed the radial extension by more than ten times.

[0021] The expandable element may be configured to provide a wall thickness when expanded of 0.02mm to 2mm, or 0.05mm to 0.5mm, preferably 0.1mm to 0.2mm.The wall thickness may be substantially constant.

[0022] The expandable element may be adapted so that the expandable element has a thicker wall thickness in the expanded state than in the non-expanded state (e.g., the thickness in the expanded state may be two, three, four, five, six times greater than in the non-expanded state, etc.). Alternatively, it is also possible to provide a wall thickness within the above range in both the inflated state and the non-inflated state.

[0023] By adapting the expandable element such that it obtains a wall thickness within the above mentioned range, it may be facilitated that the expandable element contributes only to a negligible extent to the overall outer diameter of the catheter, thereby facilitating small sized catheters with a large inner shaft lumen.

[0024] The expandable element may be adapted such that it may be at least partially deployed in a distal direction of the catheter.

[0025] In some applications, the expandable element can be adapted so that it can be folded inwardly into itself, similar to a rolling membrane, so that the expandable element can be rolled out, for example due to or supported by the expansion of the expandable element. The expandable element can be adapted, for example, as a rolling membrane, so that it preferably rolls out along the longitudinal axis of the catheter, preferably in the distal direction.

[0026] By adapting the expandable element so that it can be expanded, the volume occupied by the expandable element in the non-expanded state can be minimized. Thus, it can be ensured that the expandable element does not restrict the use of the catheter so that the catheter cannot be pushed into certain areas of interest that may have a relatively narrow inner diameter.

[0027] The expandable element may include an outer cylindrical element and an inner cylindrical element, wherein the inner cylindrical element may be disposed at least partially within the outer cylindrical element such that the expandable volume is defined as a hollow cylindrical volume therebetween.

[0028] At least one of the outer cylindrical element and / or the inner cylindrical element may be made of a sheet element (e.g., a film) formed into a cylindrical shape. In some examples, the inner cylindrical element and the outer cylindrical element may also be integrally formed from a single sheet element. In other cases, at least one of the outer cylindrical element and / or the inner cylindrical element may be provided as a molded and / or integral cylindrical element (e.g., made of a moldable plastic material).

[0029] The inner cylindrical element may be arranged concentrically within the outer cylindrical element.The hollow cylinder may surround the inner shaft lumen of the catheter, separated from the inner shaft lumen only by the inner cylindrical element.

[0030] By providing the outer cylindrical element and the inner cylindrical element such that a hollow cylinder is formed therebetween, a cylindrical expanded volume of the expandable element may be defined.Thereby, a symmetrical extension of the expandable element along the longitudinal axis of the catheter and also along the radial direction of the expandable element may be facilitated.

[0031] The proximal ends of the inner cylindrical element and the outer cylindrical element may be designed in an open manner, for example, they may not be connected to each other. The proximal ends of the inner cylindrical element and the outer cylindrical element may thus form the two proximal ends of the expandable element. For example, the proximal ends of the inner cylindrical element and the outer cylindrical element may be connected to the inner shaft.

[0032] Each of the inner cylindrical element and the outer cylindrical element may comprise a distal end, and wherein the distal ends may be connected to each other. The connection of the inner cylindrical element to the outer cylindrical element may be liquid-tight, preferably liquid-tight. A liquid-tight or fluid-tight connection may be understood as a connection that may prevent liquid and fluid, respectively, from escaping through the connection, such that the expandable volume may be expanded by the fluid / liquid. The connected distal ends of the cylindrical elements may be connected to the outer element, as described herein.

[0033] Instead of being connected at their distal ends, the inner cylindrical element and the outer cylindrical element may also be formed integrally at the distal ends. For example, the sheet-like element may be folded onto itself. Subsequently, the folded element may be arranged cylindrically, wherein the cylinder axis extends perpendicularly to the direction of the seam or notch of the folded sheet-like element. Thus, the seam or notch may form the entire distal end of the expandable element, and on the opposite side, two proximal ends may be formed.

[0034] The inner cylindrical member and the outer cylindrical member may be connected to each other proximal to at least one distal end of the expandable member.

[0035] The proximal side of the distal end of the expandable element can be understood as a position separated from the distal end of the expandable element by at least 1 cm, 2 cm, 3 cm, 5 cm, 10 cm or at least 20 cm in the proximal direction. By connecting the inner cylindrical element to the outer cylindrical element, a substantially constant wall thickness of the hollow cylinder formed between the inner cylindrical element and the outer cylindrical element (as measured from the outer side of the inner cylindrical element and the inner side of the outer cylindrical element in the radial direction) can be ensured. Therefore, asymmetric expansion of the expandable element can be suppressed.

[0036] The expandable element comprises at least two, preferably 3, 5 or more fixing points and / or at least one fixing seam arranged at least partially along the longitudinal axis (L) of the catheter. The at least two fixing points may be separated from each other by 2 mm to 5 mm. For example, the expandable element may comprise 5 fixing points (e.g., welding points) or more fixing points, which are radially spaced 72 degrees from each other at a (longitudinal) distance of 3 mm to 5 mm. For example, two fixing seams are arranged at least partially along the longitudinal axis (L) of the catheter.

[0037] The inner cylindrical element may be connected to the outer cylindrical element at at least two fixing points, wherein the at least two fixing points may be separated from each other by 2 mm to 5 mm.

[0038] By providing the expandable element or the inner and outer cylindrical elements with at least two fixing points, an asymmetric expansion of the expandable element can be avoided, since the radial distance between the outer side of the inner cylindrical element and the inner side of the outer cylindrical element can be kept constant. This can avoid that the lumen of the inner shaft of the catheter can be blocked by (asymmetrically) expanding the expandable element. Between the fixing points, there can be no connection between the inner and outer cylindrical elements, so that the fluid can propagate freely between the inner and outer cylindrical elements.

[0039] In some applications, the expandable element may be provided with more than two fixing points, for example, with four, eight, twelve, etc. The plurality of fixing points may be arranged in a pattern.

[0040] The inner cylindrical element can be connected to the outer cylindrical element by at least one fixing seam, preferably by at least two fixing seams, arranged at least partially along the longitudinal axis of the catheter. This can ensure a specific control of the wall thickness and the inflation process can also be controlled particularly well. In particular, it can be ensured that the spacing of the inner circular element and the outer circular element relative to each other remains constant.

[0041] If at least two fixing seams are implemented, for example three fixing seams, the fixing seams can be separated from each other by the same angular interval, as seen from an incision through the expandable element perpendicular to the longitudinal axis of the catheter. The seams can extend parallel to the longitudinal axis of the catheter. However, it can also be considered that they include a spiral shape, for example spiraling along the inner cylindrical element and the outer cylindrical element.

[0042] The connection may be provided by welding. Welding may be based on applying radiation (e.g. laser radiation) to two corresponding overlapping parts of the inner cylindrical element and the outer cylindrical element, preferably in contact with each other. The radiation source may be adapted so that the radiation it emits may be sufficient to heat the overlapping parts at least locally to such an extent that they locally melt and form a connection with each other. Additionally or alternatively, welding may also be based on friction welding and / or hot air welding. In some cases, the connection may be established additionally or alternatively by gluing.

[0043] Providing the connection by welding can provide a durable and cost effective connection.

[0044] The inner shaft can include a first tubular element and a second tubular element, wherein the first tubular element can be arranged in the second tubular element, thereby defining an annular lumen. The first tubular element can be arranged concentrically in the second tubular element. The first tubular element and the second tubular element can be provided with a hollow inner lumen. In some cases, the first tubular element can be movable relative to the second tubular element along the longitudinal axis of the catheter.

[0045] At least one of the first tubular element and the second tubular element may be made of a flexible material. In other cases, at least one of the first tubular element and the second tubular element may be made of a rigid, non-flexible material (e.g., metal or any other suitable material). The annular lumen may preferably be in the shape of a hollow cylinder disposed between the first tubular element and the second tubular element.

[0046] The expandable volume of the expandable element may be in fluid communication with the annular lumen.

[0047] In an example, the first tubular element can be connected to the inner cylindrical element of the expandable element, for example, to the proximal end of the inner cylindrical element. In some cases, the second tubular element can be connected to the outer cylindrical element of the expandable element, for example, to the proximal end of the outer cylindrical element. Thus, both proximal ends of the expandable element can be connected to the inner shaft. Thus, the connection of the expandable element to both the first tubular element and the second tubular element can allow a simplified expansion and contraction process of the expandable element from the proximal end of the catheter and from a position outside the patient's body.

[0048] The expandable element may be connected to the distal end of the inner shaft. The inner cylindrical element may be connected to the first tubular element, and the outer cylindrical element may be connected to the second tubular element. Preferably, the proximal end of the inner cylindrical element may be connected to the distal end of the first tubular element, and the proximal end of the outer cylindrical element may be connected to the distal end of the second tubular element.

[0049] By means of aspects described herein, an expandable element may be provided that provides an expandable lumen having a predetermined inner diameter in a dimensionally stable manner.

[0050] The catheter further comprises a rolling membrane, wherein at least one distal end of the expandable element may be connected to the rolling membrane.

[0051] A rolling membrane may be understood as a hose-like flexible and tubular element, wherein one end of the element (e.g. the distal end as seen in the unfolded state) is at least partially folded into itself. Thus, a (hollow) inner rolling membrane lumen may be formed, which may, for example, extend from the proximal side of the rolling membrane catheter to the distal end of the rolling membrane catheter. For example, due to filling the rolling membrane catheter with fluid from the proximal side of the catheter, the rolling membrane may be at least partially unfolded, i.e. spread out along the axis of the catheter in, for example, the distal direction. Due to its flexible properties, the rolling membrane may be able to roll out along the axis of the blood vessel and, due to its rolling motion, may reach even branched and / or thin arteries. Due to its unfolding, the rolling membrane may propagate along the vessel wall in a rolling manner (e.g., minimizing friction with the vessel wall).

[0052] The rolling membrane can be provided as a hose-like element with an inner rolling membrane lumen, wherein at least a portion of the hose-like element, preferably a distal portion (as seen when the rolling membrane is rolled out) is folded inwardly into itself. The rolling membrane can preferably be adapted so that it can be rolled out along the longitudinal direction of the catheter (along the distal direction).

[0053] At least one distal end of the expandable element may be connected to the distal end of the rolling membrane (as seen when the rolling membrane is rolled out) (the distal end of the rolling membrane may also be understood as the most proximal inner portion of the rolling membrane when it is rolled out).

[0054] By providing the catheter with a rolling membrane, a simplified movement of the distal end of the catheter through the patient's blood vessel to the area of ​​interest can be supported. This reduces the complexity of controlling and stirring the catheter along the patient's blood vessel and can therefore also contribute to reducing the complexity of the treatment. If the distal end of the rolling membrane reaches the area of ​​interest, the rolling membrane can undergo further stabilization by means of an expandable element. This makes it possible to avoid kinking of the rolling membrane. Due to the expansion, the inner lumen grows to the desired size and allows sufficient space for further equipment. Kinking and deformations that lead to flattening of the inner lumen are avoided.

[0055] The rolling membrane can be connected to the outer shaft. For example, the proximal end of the rolling membrane (when the rolling membrane is rolled out) can be connected to the outer shaft.

[0056] The rolling film can be spread by providing a liquid or fluid (e.g., from the proximal direction of the catheter) to the annular lumen defined between the inner side of the outer shaft and the outer side of the second tubular element of the inner shaft. Additionally or alternatively, it can be spread by moving the inner shaft distally and / or the outer shaft proximally (or, if no separate outer shaft is provided, the proximal end of the rolling film).

[0057] The expandable volume of the expandable element may be adapted to allow delivery of a medical drug and / or a medical device from the proximal portion of the catheter to the distal portion of the catheter.

[0058] The versatility of the catheter can be increased by providing an inner shaft lumen that allows the delivery of medical drugs and / or medical devices (e.g., stents). Due to the expandable element (set to a non-expanded state at the beginning of the catheter-based intervention), the catheter can be pushed into the patient's narrow blood vessels (e.g., into a blood vessel with an inner diameter similar to the outer diameter of the catheter). Therefore, the catheter can reach even narrow blood vessels. Prior to potential stent implantation / drug delivery, the catheter can be further stabilized by expanding the expandable element. At the same time, a safe inner channel is provided by the inner lumen of the expandable element, which can provide a predetermined diameter (e.g., for delivering four French devices). The predetermined inner diameter can be in the range of 0.5mm to 2mm, 0.8mm to 1.8mm, 1mm to 1.5mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The following drawings are provided to support the understanding of the present invention:

[0060] Figure 1 is an illustration of an exemplary catheter having an expandable element.

[0061] Figure 2 is an illustration of an exemplary catheter having an expandable element with welds. DETAILED DESCRIPTION

[0062] Figure 1 The catheter 1 is exemplarily shown and comprises an outer shaft 13, an inner shaft 2, a rolling membrane 12 and an expandable element 7. The inner shaft 2 is at least partially arranged in the outer shaft 13. The expandable element 7 comprises at least two proximal ends 11 connected to the inner shaft 2 and at least one distal end 10 connected to the rolling membrane 12.

[0063] The inner shaft 2 may be located at the proximal end P of the catheter 1 . The inner shaft 2 includes an inner shaft lumen 3 . The inner shaft lumen 3 extends from the proximal end of the inner shaft 2 to the distal end of the inner shaft 2 .

[0064] The inner shaft 2 may include a first tubular element 4 and a second tubular element 5, wherein the first tubular element 4 may be concentrically arranged within the second tubular element 5. An annular lumen 6 may be defined between the first tubular element 4 and the second tubular element 5. The first tubular element 4 and the second tubular element 5 may be formed by an inner shaft having different diameters.

[0065] The expandable element 7 is preferably arranged at the distal end of the inner shaft 2. The expandable element 7 comprises an expandable volume 15.

[0066] The expandable element 7 may comprise an outer cylindrical element 8 and an inner cylindrical element 9 , wherein the outer cylindrical element 8 may be connected to the inner cylindrical element 9 at least at a distal end 10 of the expandable element 7 .

[0067] Preferably, the proximal end 11 of the expandable element 7 is connected to the distal end of the inner shaft 2. A connection may be provided such that fluid communication of the expandable volume of the expandable element 7 with the annular lumen 6 is established. Furthermore, the expandable lumen of the expandable element 7 may be in fluid communication with the inner shaft lumen 3 of the inner shaft 2.

[0068] exist Figure 1 , the proximal end of each of the outer cylindrical element 8 and the inner cylindrical element 9 can be connected to the inner shaft. Specifically, the proximal end of the outer cylindrical element 8 can be connected to the second tubular element 5 of the inner shaft 2. The proximal end of the inner cylindrical element 9 can be connected to the first tubular element 4 of the inner shaft 2.

[0069] exist Figure 1 In the embodiment, the expandable element 7 is only partially expanded. When further expanded, the expandable element 7 may extend mainly along the longitudinal axis L of the catheter, preferably in the distal direction D.

[0070] The catheter 1 may further comprise a rolling membrane 12. The rolling membrane 12 is connected to the expandable element 7, for example to the distal end 10 of the expandable element 7. When the rolling membrane 12 is deployed, the connection point between the distal end 10 of the expandable element 7 and the rolling membrane 12 may form the distal end of the catheter.

[0071] At its opposite end, the rolling membrane 12 may be connected to the distal end of the outer shaft 13 .

[0072] An inner lumen 14 is formed between the outer shaft 13 and the inner shaft 2. By providing a fluid to the inner lumen 14, preferably from the proximal end P of the catheter 1, rolling out of the rolling film 12 can be initiated. The rolling film 12 can be adapted to roll out along the distal direction D and the longitudinal axis L of the catheter 1. The rolling out can be accompanied by a distal movement of the inner shaft 2 and / or a proximal movement of the outer shaft 13.

[0073] For example, once the rolling membrane 13 has been rolled out, the expandable element 7 can be expanded. This can ensure the stability of the catheter 1. It can also ensure that an inner lumen (including the inner lumen of the expandable element 7) is provided to safely deliver drugs and / or devices to the distal end of the catheter 1. For example, the expandable element 7 can be adapted so that in the expanded state, its inner lumen can include a diameter that is substantially the same as the inner diameter of the inner shaft lumen 3 of the inner shaft 2.

[0074] Figure 2 A catheter 1 is shown, comprising an outer shaft 13 , an inner shaft 2 , a rolling membrane 12 and an expandable element 7 .

[0075] The inner shaft 2 is at least partially arranged within the outer shaft 13. The inner shaft 2 may be located at the proximal end of the catheter 1. The inner shaft 2 includes an inner shaft lumen 3. The inner shaft lumen 3 extends from the proximal end of the inner shaft 2 to the distal end of the inner shaft 2.

[0076] At the distal end of the inner shaft 2, an expandable element 7 is arranged. The expandable element 7 includes an expandable volume. The expandable element 7 includes at least two proximal ends 11 and at least one distal end 10. A rolling membrane 12 is connected to at least the distal end 10 of the expandable element 7. The proximal end 11 of the expandable element 7 is connected to the distal end of the inner shaft 2. The expandable volume of the expandable element 7 is in fluid communication with the inner shaft lumen 3 of the inner shaft 2.

[0077] The rolling membrane 12 is connected to the expandable element 7, for example to the distal end 10 of the expandable element 7. When the rolling membrane 12 is rolled out, the connection point between the distal end 10 of the expandable element 7 and the rolling membrane 12 can form the distal end of the catheter. At its opposite end, the rolling membrane 12 is connected to the distal end of the outer shaft 13.

[0078] An inner lumen 14 is formed between the outer shaft 13 and the inner shaft 2. By providing a fluid to the inner lumen 14, preferably from the proximal end of the catheter 1, rolling out of the rolling film 12 can be initiated. The rolling film 12 can be adapted to roll out along the distal direction D and the longitudinal axis L of the catheter 1. The rolling out can be accompanied by a distal movement of the inner shaft 2 and / or a proximal movement of the outer shaft 13.

[0079] The expandable element comprises at least two fixing points 20 and / or at least one fixing seam arranged at least partially along the longitudinal axis (L) of the catheter.

[0080] Further exemplary embodiments are provided below.

[0081] A method for operating a catheter having an expandable element having an expandable volume may be provided. The catheter may be any catheter as described herein. The method may include the steps of inserting the catheter into a cavity (such as a blood vessel) of a patient. Expanding the expandable volume of the expandable element, preferably after the catheter has been inserted.

[0082] In some cases, a further step of delivering a medical device and / or substance through the inner lumen of the expandable element may be provided, preferably after expanding the expandable volume of the expandable element.

[0083] In some examples, the inserting step may include inserting the catheter into the blood vessel with the expandable element in a deflated state. In some examples, the step of expanding the expandable volume may include expanding after the catheter has reached a predetermined (final) position in a cavity (e.g., a blood vessel).

[0084] In some examples, the method may further include the step of manipulating the catheter so that the inner lumen of the expandable element extends along the longitudinal axis of the catheter and extends to the distal end of the catheter. For example, a rolling membrane connected to the expandable element can be manipulated to be in a spread-out state so that the distal end of the expandable element can be positioned at the distal end of the catheter. This can be achieved as described herein, for example, by moving the inner element and / or the outer element of the catheter as described herein and / or by expanding the rolling membrane.

[0085] For example, the delivering step may include delivering the medical device and / or substance in a distal direction, preferably to the distal end of the catheter.

[0086] In some cases, the method may include the step of deflation of the expandable element. This step may preferably occur after the delivering step (if present).

[0087] The method may further comprise the step of retracting the catheter from the blood vessel. Preferably, this step may be performed after the step of deflation of the expandable element. The retracting step may comprise proximally moving the inner shaft and / or outer shaft of the catheter and / or deflation of the rolling membrane.

Claims

1. A catheter (1), comprising: An outer shaft (13), an inner shaft (2), a rolling membrane (12) and an expandable element (7) including an expandable volume (15); wherein the inner shaft (2) includes an inner shaft lumen (3), and the inner shaft is at least partially arranged in the outer shaft (13), and the rolling membrane (12) is connected to the outer shaft (13); and wherein the expandable element (7) includes at least two proximal ends (11) connected to the inner shaft (2) and at least one distal end (10) connected to the rolling membrane (12).

2. The catheter (1) according to claim 1, wherein the expandable element (7) extends, at least when expanded, along the longitudinal axis (L) of the catheter by 20 cm to 40 cm, preferably by 26 cm to 35 cm.

3. The catheter (1) according to any of the preceding claims, wherein the expandable element (7) is configured to provide a wall thickness of about 0.02 mm to 0.5 mm, preferably about 0.1 mm to 0.2 mm when expanded.

4. The catheter (1) according to any of the preceding claims, wherein the expandable element (7) and / or the rolling membrane can be at least partially rolled out in a distal direction (D) of the catheter.

5. The catheter (1) according to any of the preceding claims, wherein the expandable element (7) comprises an outer cylindrical element (8) and an inner cylindrical element (9), wherein the inner cylindrical element (9) is at least partially arranged inside the outer cylindrical element (8) so that the expandable volume is defined as a hollow cylindrical volume therebetween.

6. The catheter (1) according to claim 5, wherein each of the inner cylindrical element (9) and the outer cylindrical element (8) comprises a distal end, and wherein the distal ends are connected to each other.

7. The catheter (1) according to claim 5 or 6, wherein the inner cylindrical element (9) and the outer cylindrical element (8) are connected to each other proximally of at least one distal end (D) of the expandable element (7).

8. The catheter (1) according to any one of claims 5 to 7, wherein the inner cylindrical element (9) is connected to the outer cylindrical element (8) at at least two fixing points, preferably wherein the at least two fixing points are 2 mm to 5 mm apart from each other.

9. The catheter (1) according to any one of claims 5 to 8, wherein the inner cylindrical element (9) is connected to the outer cylindrical element (8) by at least one fixing seam, preferably by at least two fixing seams, arranged at least partially along the longitudinal axis (L) of the catheter.

10. The catheter (1) according to any one of claims 5 to 9, wherein the connection is provided by welding.

11. A catheter (1) according to any of the preceding claims, wherein the inner shaft (2) comprises or consists of a first tubular element (4) and a second tubular element (5), wherein the first tubular element (4) is arranged in the second tubular element (5), preferably concentrically arranged in the second tubular element (5), thereby defining an annular lumen (6).

12. The catheter (1) according to claim 11, wherein the expandable volume (15) of the expandable element (7) is in fluid communication with the annular lumen (6).

13. The catheter (1) according to any of the preceding claims, wherein the material making up the outer shaft and the material making up the inner shaft each have a higher hardness than the material making up the rolling membrane and the material making up the expandable element.

14. The catheter (1) according to any one of the preceding claims, wherein the proximal end (11) of the expandable element (7) is connected to the distal end of the inner shaft (2).

15. The catheter (1) according to any one of claims 11 to 14, wherein the inner cylindrical element (9) is connected to the first tubular element (4) and the outer cylindrical element (8) is connected to the second tubular element (5).

16. The catheter (1) according to any one of claims 11 to 14, wherein the proximal end of the inner cylindrical element (9) is connected to the distal end of the first tubular element (4), and the proximal end of the outer cylindrical element (8) is connected to the distal end of the second tubular element (5).

17. The catheter (1) according to any of the preceding claims, wherein the inner shaft lumen (3) is adapted to allow delivery of medical drugs and / or medical devices to a distal portion (D) of the catheter.

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