BALLOON CATHETER DEVICE FOR ATRAUMATIC DILAMINATION OF HOLLOW ORGANS AND A METHOD FOR PRODUCEING SUCH A BALLOON CATHETER DEVICE

Description

[0001] The present invention relates to a balloon catheter device (balloon catheter with functional sleeve) and a method for manufacturing such a balloon catheter device with a functional sleeve. Dilation of constrictions in hollow organs using a balloon catheter is an integral part of minimally invasive therapy. This applies particularly to blood vessels. In the context of so-called endovascular therapy, atherosclerotic constrictions and occlusions of blood vessels are treated by balloon dilation.

[0002] Typically, a balloon catheter is inserted into the vascular system under image guidance. After positioning the balloon at the site of the lesion to be treated, it is inflated under high pressure. However, this standard treatment can be associated with serious complications. The balloon inflation injures the vessel wall, typically resulting in longitudinal tears. This injury can lead to clot formation in the first few days after treatment. In the following days, and for up to three months, the blood vessel wall reacts to the dilation trauma with an excessive wall response. Smooth muscle cells in the vessel wall are stimulated by the trauma and produce extracellular matrix ("intimal hyperplasia"). The associated increase in vessel wall volume leads to a recurrence of the narrowing, thus counteracting the treatment outcome.Even the implantation of a stent for permanent vessel dilation cannot prevent this. A stent is a foreign body that can, on the one hand, promote clot formation and, on the other hand, its rigidity prevents the natural pulsatile motility of the stented vessel segment, thus exerting constant irritation on the vessel wall. This irritation can, in turn, lead to excessive production of vessel wall cells with tissue ingrowth through the stent struts and thus to the formation of a renewed narrowing.

[0003] Therefore, the stents commonly implanted today are coated with an antiproliferative agent that reduces cell stimulation and matrix production. In cases of balloon angioplasty alone, without stent implantation, balloon catheters are predominantly used. The outer layer of these catheters is coated with a comparable antiproliferative agent, which is intended to be released into the vessel wall upon balloon inflation. The coating typically consists of a homogeneous, film-like covering of the outer balloon membrane, containing the active ingredient embedded in a carrier material (binder, "excipient"). The therapeutic goal is to deliver a therapeutic dose of the drug into the vessel wall for the critical period of 6 weeks to a maximum of 3 months to suppress the excessive vascular wall response (Katsanos et al., J Am Heart Assoc 2018).

[0004] In particular, WO 2016 / 151035 A1 describes a tubular sleeve for the atraumatic treatment of hollow organs. The sleeve is designed to be deployed using a balloon catheter, leaving it as an implant within the hollow organ. Thus, during balloon inflation, the sleeve separates from the balloon membrane.

[0005] US patent 2014 / 0239558 A1 describes a combination of injection molding and blow molding followed by laser cutting. This method is intended to produce a polymer stent, such as the so-called "Esprit Stent," which, like a conventional stent, opens its cells when deployed on a balloon. Furthermore, the stent is designed to be ejected from the balloon after balloon catheter deployment.

[0006] US patent 2005 / 0182361 A1 describes a sleeve made of an elastic material for protecting an underlying drug layer. The elastic sleeve is fitted over the folded balloon of the balloon catheter. The unfolded sleeve rests elastically over the folded balloon membrane and is stretched by the expanding balloon. During balloon inflation, the sleeve undergoes a significant increase in circumference, forming diamond-shaped windows from the slits. The purpose of this device is to protect the drug layer.

[0007] CN 1 11 107 889 A discloses a balloon catheter on which a cover containing a layer of medicinal drug is arranged. The drug layer, or the cover, is surrounded by a sleeve to protect the drug. The sleeve may be connected to a catheter shaft. The cover and the sleeve are not folded; only the balloon is folded. The cover is designed to be rollable to allow the application of different drugs.

[0008] EP 3 922 217 A1 discloses a tubular nonwoven structure as a drug carrier (referred to as "sleeve") for the atraumatic treatment of hollow organs, in particular for balloon dilation, wherein the sleeve is folded around a longitudinal axis in an initial state and can be unfolded in a final state to conform to the inner wall of a hollow organ, wherein the tubular sleeve is formed from at least first biodegradable polymer nanofibers and the folding of the sleeve is directed as pleating around a longitudinal axis, wherein a medical drug is embedded in the first polymer nanofibers and / or arranged in spaces between the polymer nanofibers, and wherein the first polymer fibers are designed such that they degrade as slowly biodegradable polymer nanofibers (PL) over an adjustable period of 2 weeks to 3 months, so that the drug can be released to a hollow organ wall during this period.The tubular sleeve is made of at least the first and second biodegradable polymer nanofibers.

[0009] US patent 11,000,680 B2 describes a balloon catheter device with an expandable balloon surrounded by a "cage" of axially and tangentially oriented nitinol wires. When the balloon membrane is inflated, this cage creates multiple small cushions intended to exert a more precisely controlled force distribution on the vessel wall, thereby reducing vessel wall trauma compared to a conventional balloon.

[0010] US Patent 5,810,767 A discloses a method in which an intravascular catheter comprises fluid infusion tubing with a balloon surface and, upon inflation of the balloon, defines a plurality of isolated reservoir pockets. As a result, fluid loss in a single side arm is generally limited to one or at most two of the isolated reservoir pockets, and the pressure in the remaining reservoir pockets can be maintained without significant impairment.

[0011] US 2014 / 066960 A1 describes a system comprising a balloon mounted on a catheter and an extendable structure mounted over the balloon, incorporating a variety of axial and radial stabilizing elements. This allows the balloon to be clamped in such a way that, when the balloon is inflated, isolated sections of the balloon protrude through openings in the extendable structure.

[0012] US patent 2006 / 135985 A1 discloses a method and device for introducing an expandable body into a blood vessel, expanding the expandable body from a first diameter to a second diameter different from it, and changing the shape of the inner diameter of the blood vessel at a lesion without the lesion tearing.

[0013] Similar devices and methods are known from DE 10 2012 007 640, WO 02 076 700 A1, US 5 443 495 A1, DE 10 2006 020 687 A1, US 2005 / 0 090 888 A1, DE 2005 056 529, US 2002 / 0 045 930 A1, US 2005 / 0 125 053 A1, US 2008 / 0 262 594, US 5,507,770 A, US 6,059,823 A and US 2010 / 249946 A1.

[0014] The object of the present invention is to provide a medical instrument or device for the atraumatic treatment of hollow organs, which represents an alternative to the medical devices known from the prior art.

[0015] From WO 2016 / 151035 A1 and EP 3 922 217 A1, a tubular sleeve and a tubular nonwoven structure as a drug carrier emerge, which can be jettisoned by means of a balloon of a balloon catheter.

[0016] Furthermore, a method for manufacturing such a medical instrument should be provided.

[0017] These problems are solved by a device according to claim 1 and a method according to claims 14 and 15. Advantageous embodiments thereof are specified in the dependent claims.

[0018] According to the invention, a balloon catheter device is provided for the atraumatic dilation of hollow organs. This comprises a balloon catheter with a balloon, a tubular flat functional sleeve applied to the balloon for directed segmented cushion-like expansion of the balloon.

[0019] The invention is characterized in that the functional sleeve is folded together with the balloon around a longitudinal axis of the sleeve in an initial state, and wherein the folding of the functional sleeve is directed as pleating around a longitudinal axis of the sleeve and can be unfolded in a final state to abut an inner wall of a hollow organ, and wherein the tubular functional sleeve has flat sections and / or flat struts that define passage openings, so that the functional sleeve serves to define the section-wise expansion of the balloon, and wherein the functional sleeve is connected to the balloon in the area of ​​the flat sections and / or the flat struts.

[0020] Atraumatic treatment of hollow organs can refer to two types of procedures. First, it can involve dilating the organ, or second, a time-limited implantation in which a medication is administered. Such a time-limited application lasts for at least two or three minutes, and up to a maximum of five or ten minutes. The simultaneous release of the medication into the organ wall typically lasts for weeks to months.

[0021] The flat sections and / or struts that define the openings of the functional sleeve allow for controlled and, in particular, enhanced balloon inflation, resulting in a uniform cushioning of the balloon in the area of ​​the openings. This achieves (compared to conventional balloons) a more even contact and a more uniform distribution of force on the hollow organ or blood vessel wall during balloon inflation. Consequently, localized, large-scale trauma to the wall and the associated tearing can be reduced.

[0022] In particular, the flat functional sleeve with through-holes reduces or prevents the formation of local stress peaks between the balloon shell and the vessel wall during the expansion process, so that no large cracks can form in the vessel wall during balloon expansion.

[0023] The area in which the cushions are formed will be referred to below as the first functional area.

[0024] In contrast to the balloon catheter device according to the invention, a wire cage, such as that described in US 11,000,680 B2, also exerts trauma on the vessel wall due to local impressions combined with shearing during the deployment process. Furthermore, the wire cage significantly increases the insertion diameter of a balloon catheter device.

[0025] The sleeve according to the invention is connected to the balloon membrane and is foldable and expandable together with the balloon membrane of the balloon catheter. However, the sleeve according to the invention does not have microcompartments, but rather through-openings that are window-like and / or in the form of slits.

[0026] The advantage of flat struts in the functional sleeve compared to a wire structure for segmenting balloon inflation lies in the reduced profile during folding, allowing for a smaller diameter delivery catheter. A low-profile delivery catheter facilitates insertion. Furthermore, a wire structure during balloon inflation can lead to additional damage to the hollow organ wall due to a combination of wire compression and shearing.

[0027] The functional sleeve according to the invention is thus designed in such a segmented manner or has a grouped arrangement of through openings (windows, slots) that the functional sleeve, in its unfolded state, has a contact surface on its outer contour opposite the hollow organ wall in the form of plate-shaped or flat sections or struts.

[0028] In the context of the present invention, the term "flat" means that the tubular sleeve itself and also the struts and sections forming the tubular sleeves have a greater extent in a plane parallel to the balloon surface compared to a thickness orthogonal to the balloon surface.

[0029] According to the invention, the sleeve is thus connected to the balloon membrane essentially along its entire axial length and is first folded together with the membrane and subsequently unfolded together with the membrane. This means that the sleeve always remains on the balloon membrane and, after cushion-shaped balloon inflation of the hollow organ combined with the application of the active ingredient into the organ wall, is removed from the hollow organ together with the membrane.

[0030] A connection between the balloon and the sleeve is preferably achieved by the adhesion of an active ingredient-containing adhesive layer, e.g., a gel, which is arranged between the balloon or balloon membrane and the functional sleeve. Additionally and / or alternatively, a point and / or line connection by laser welding, or a surface connection by bonding, in particular a connection across all flat surfaces or struts, can be provided.

[0031] The functional sleeve exhibits, in particular, a higher stiffness with approximately the same wall thickness or a higher modulus of elasticity than the balloon membrane.

[0032] This significantly promotes the cushion-like expansion. This means that the sleeve should have a higher tensile stiffness than the balloon membrane in order to exert a circumferential limiting effect on the expanding balloon membrane in the area of ​​its surfaces / struts. This allows the cushion effect to develop ideally. An approximately equal tensile stiffness for the sleeve and balloon membrane, or even slightly less, is also conceivable.

[0033] In particular, a medical drug layer can be arranged between the balloon of the balloon catheter and the functional sleeve.

[0034] The medical agent can then be released to the vessel wall in the area of ​​the openings.

[0035] This area is referred to as the second functional area and corresponds to the size of the first functional area.

[0036] The flat sections and / or flat struts ensure that the medical drug layer, which may be located under the functional sleeve, is protected, particularly when the balloon catheter device is folded for low-profile storage and during transport to the site of action.

[0037] The sleeve preferably has a diameter that corresponds approximately to the diameter of the unfolded or expanded balloon.

[0038] The through-openings can be designed as, in particular, laser-cut slots for the application of medication or active ingredients, wherein in the functional sleeve, sections with axial slots, which are referred to as axial sections, and sections with tangential slots, which are referred to as tangential sections, can be formed alternately in an axial direction of the functional sleeve, and wherein the axial sections and the tangential sections form the first functional area and are spaced apart from each other.

[0039] According to the invention, by providing alternating axial sections with corresponding axial slots and tangential or radial sections with corresponding tangential sections, a constant or essentially uniform expansion of the diameter of the sleeve and the balloon in the axial direction occurs.

[0040] The tangential sections form decoupling sections between the axial sections in order to enable an approximately constant diameter in the radial direction over a substantially entire length of the device in the axial direction.

[0041] In particular, the axial sections and the tangential sections are designed and spaced apart in an axial direction in such a way that they do not overlap.

[0042] Furthermore, the axial slots of the axial sections and the tangential slots of the tangential sections can be designed and arranged such that they do not overlap each other in the tangential direction. This means that neither the axial slots nor the tangential slots are offset from each other.

[0043] In the prior art, slots are often arranged offset from one another. According to the invention, the axial slots can be of the same length and width and arranged tangentially around the circumference at approximately equal intervals and tangentially aligned with one another. Furthermore, according to the invention, the tangential slots can be of the same length and width and arranged tangentially around the circumference at approximately equal intervals and tangentially aligned with one another.

[0044] The inventors of the present invention have recognized that such an alternating arrangement of identical axial and tangential slots along a sleeve axis or in the axial direction enables optimal or improved cushion formation. Since the balloon catheter device has a cylindrical shape, the wall stress in the functional sleeve under balloon pressure is twice as high in the tangential direction as in the axial direction (Kessel formula). The axial slots expand under internal balloon pressure. The relatively small expansion of each individual axial slot accumulates around the circumference of the sleeve, resulting in an effective cushion-like expansion of the diameter. No significant expansion occurs in the area of ​​the tangential slots, thus resulting in a relative constriction around the circumference of the sleeve. However, drug delivery can still be achieved via the tangential slots, as is also possible in the area of ​​the axial slots.

[0045] The decoupling sections formed by the tangential segments cause the balloon to constrict in these areas, resulting in a substantially constant diameter in the axial segments. This leads to a uniform distribution of forces in the radial outward direction. In this way, any resulting trauma to the hollow organ is minimized, as only smaller and more evenly distributed tears occur in the organ wall.

[0046] In contrast to known devices, in which a bulbous or balloon-like or approximately spherical expansion occurs, the device according to the invention results in an expansion that is essentially cylindrical in the axial direction.

[0047] It may be provided that the sleeve has alternating axial sections and tangential sections in the axial direction.

[0048] Because the balloon and the sleeve are connected in their connection areas, the balloon catheter device is designed in such a way that the functional sleeve and the balloon fold together or can be folded together by folding along formed fold lines when the balloon is deflated or when the sleeve is removed from a hollow organ.

[0049] The entire functional sleeve, and thus the flat struts or flat sections forming the functional sleeve, may have pores that have the task of releasing the active ingredient underneath to the hollow organ wall when unfolded, but do not have a cushion-forming effect.

[0050] The pores can have a diameter of approximately 50µm to 100µm.

[0051] The corresponding release of the medical agent to a vessel wall can then occur throughout the entire area of ​​the mantle surface, i.e., both in the area of ​​the openings or in the area of ​​the cushions and via the pores in the area of ​​the flat struts.

[0052] According to such an embodiment, the second functional area extends over the entire outer wall of the functional sleeve and is therefore advantageously enlarged accordingly, so that the medical agent can be released over a larger area and / or so that more agent can be released.

[0053] The medical drug layer can be formed together with a polymer, for example a biodegradable polymer, or in the form of a nonwoven structure made of a polymer, e.g. a biodegradable polymer.

[0054] The integrity of this layer or nonwoven structure is then protected by the functional sleeve during the folding and unfolding process.

[0055] Preferably, the medicinal agent can be contained in a polymer gel formulation that forms the medicinal agent layer.

[0056] This is advantageous in that the polymer gel formulation gels and increases in volume upon contact with blood serum, so that the medical agent can be squeezed out between the balloon membrane and the functional sleeve via their openings when the balloon is inflated, and thus efficiently transferred into the hollow organ wall.

[0057] The integrity of this gel layer is also protected by the functional sleeve during the folding process, storage and transport to the point of action.

[0058] The procedure involves folding the balloon and the functional sleeve together and unfolding them within a blood vessel. After the vessel is dilated by cushion-like balloon inflation and the drug is transferred into the vessel wall through the openings and also via the pores, thus covering the entire outer wall of the functional sleeve, the functional sleeve and balloon are folded together again and removed.

[0059] Preferably, the functional sleeve can be made of a stretch-resistant polymer film, e.g., UHWPE polyethylene or non-compliant Pebax®.

[0060] The balloon itself can be made of, for example, semi-compliant or compliant Pebax®.

[0061] The through-openings can be designed as slots or elongated openings, in particular axial slots or sinusoidal axially oriented slots and / or as approximately rectangular or approximately elliptical or approximately circular windows or window-like openings in an otherwise (except for the pores, if present) continuously flat shell wall of the functional sleeve.

[0062] Preferably, the through-openings have rounded corners to prevent cracking caused by notch effects.

[0063] In addition, two or three or four or five or more rows of (preferably axially oriented) slots can be arranged along the longitudinal axis of the sleeve.

[0064] Additionally and / or alternatively, the sleeve can be provided with windows over sections or in sections or over its entire surface.

[0065] Between two or more axially extending, adjacent slots, predetermined tear points can be formed in order to combine the advantages of a functional sleeve that is as closed as possible with the advantages of greater cushion formation during use in the storage and transport of the balloon catheter device.

[0066] By providing axial predetermined breaking points in the area between two or more adjacent axial slots, a larger cushion formation is possible, even if only short axial slots are provided.

[0067] Axially oriented, slit-like openings enhance cushion formation (i.e., outward bulging of the balloon membrane), whereas tangentially oriented, slit-like openings contribute practically nothing to cushion formation (relative constriction of the balloon membrane). The physical explanation is provided by the so-called "boiler formula," according to which the tangential wall stress, acting perpendicular to the axial slits of the functional sleeve during balloon expansion, is twice as great as the axial wall stress. Axially oriented slits widen under internal pressure; this effect is cumulative when grouped around the circumference. Tangentially oriented slits, on the other hand, hardly widen at all.

[0068] In the area of ​​the through-opening, the functional sleeve forms a corresponding first functional area for cushion formation. The active ingredient is released via the second functional area, which either corresponds to the first or preferably comprises the entire outer wall of the functional sleeve, including through-openings, provided the functional sleeve has pores.

[0069] Between the functional sleeve and the balloon, the medical agent layer containing a medical agent can be arranged, with the medical agent layer acting as a coating of the balloon membrane (e.g. by dip coating) made of a polymer (or a combination of polymers), in particular biodegradable, and a medicinal agent, and / or a polymer nonwoven fabric containing the medicinal agent, sprayed onto the balloon membrane, in particular biodegradable, and / or designed as a tubular intermediate sleeve with a nonwoven structure made of a polymer, in particular biodegradable, and the medicinal agent, wherein the medicinal agent is then embedded in microcompartments between the polymer fibers, and wherein this is advantageously in conjunction with corresponding window-like openings, and / or wherein the medicinal agent is contained in a polymer gel formulation as an agent layer.

[0070] The medical active ingredient can thus be contained in a polymer gel formulation which, after coating the balloon membrane, dries with the evaporation of the solvent, is stored dry with the balloon, and upon application gels and increases in volume through contact with water or blood serum, whereby pure hydrogels or combinations with oleo-gels (organo-gels) can be used.

[0071] The functional sleeve arranged over the medical agent thus also serves as protection for the active ingredient layer when the balloon is folded for storage and subsequent transport to the site of action, so that upon contact with liquid and balloon expansion, the drug-containing, in particular biodegradable, polymer is pressed outwards in the area of ​​the openings of the sleeve (windows, slits and pores) and can be applied to a vessel wall.

[0072] This drug delivery by compression through the expanding balloon membrane, through the openings of the functional sleeve onto its outer surface, is particularly effective when the drug is contained in a polymer-gel formulation that gels and expands upon contact with blood serum. After the gel layer expands in volume, compression by the balloon membrane forces the gel through the openings of the sleeve into the wall of the hollow organ.

[0073] If the medical drug layer is formed with biodegradable polymer nanofibers, these detach from the balloon in the area of ​​the through-holes when the balloon is inflated and form (micro)flakes, which are then pressed against the hollow organ wall (especially the vessel wall).

[0074] Following balloon deflation, a gel layer or fibers adhere to the hollow organ wall. The active ingredient is encapsulated within the gel or degradable fibers and, during the biodegradation of the gel or fibers, maintains a therapeutically effective drug concentration in contact with the hollow organ wall for a critical period. Simultaneously, it also partially seals any longitudinal cracks in the hollow organ wall created by balloon dilation. In this way, the drug delivery and its concentration can be optimally adjusted over time to suit the specific application.

[0075] The therapeutically required time period is covered by the release of the active ingredient via the degradation of the biodegradable gel or the polymer nanofibers, ensuring a therapeutically effective dosage level. The biodegradation of the gel or the degradation of the fibers, and thus the release of the active ingredient, should be complete once the critical phase has passed, so that no permanent residues remain in the vessel.

[0076] In the context of the present invention, the term "biodegradable" means that contact of the polymer gel or the polymer nanofibers with body fluid and a hollow organ wall (specifically: blood and vessel wall) induces a decomposition or degradation process of this polymer.

[0077] Preferably, the folding of the tubular functional sleeve can be designed as pleating, or the sleeve itself can be pleated. Within the scope of the present invention, "pleating" means folding the sleeve into 2 to 5 (preferably 3) equally sized pleats evenly distributed around the circumference (preferably 3 x 120°) and extending in the axial direction, wherein the pleats are wound uniformly and in the same direction around the longitudinal axis of the balloon catheter and applied to it. Pleating makes it possible to reduce the outer diameter of the tubular sleeve in its unfolded state.

[0078] First and / or second polymer nanofibers can be intended to be biodegradable polymers.

[0079] The first polymer nanofibers can be formed from slowly degradable polymer fibers (PL). The second polymer nanofibers can be formed from rapidly degradable polymer fibers (PS).

[0080] Preferably, only the slowly degradable polymer (PL) can contain an active ingredient. An anticoagulant such as heparin or another anticoagulant may optionally be incorporated into the rapidly degrading polymer (PS).

[0081] The degradable polymer may preferably exhibit hydrophilic and / or lipophilic properties. The degradation rate depends on the polymer type (e.g., in PLGA - poly-lactide co-glycolide) by the ratio of GA to LA (a higher LA content reduces hydrophilicity and therefore leads to slower dissolution), the molecular chain length (a high molecular weight or a longer chain length results in slower dissolution), and the hydrophilicity of the side groups (e.g., the methyl side groups in PLA are hydrophobic and thus delay dissolution, or in PLGA, a hydrophilic carboxyl group leads to faster dissolution than an ester group).

[0082] Thus, it is intended that the medical drug layer in the area of ​​the passage openings breaks down into multiple spots through the biodegradable polymer gels or into multiple "flakes" or "microflakes" formed by biodegradable polymer nanofibers, which are flat or even-surface and adhere to the hollow organ wall.

[0083] The biocompatible polymer of the polymer gels or the polymer nanofibers can be formed from polymers based on lactic acid (polylactide, PLA), glycolic acid (polyglycolide, PGA) and their copolymers (poly(lactide-co-glycolide), -PLGA), as well as poly(ε-caprolactone), polyethylene glycol, polyethylene oxide, polysebacic acid, poly(trimethylene carbonate), poly(ethylene-co-vinyl acetate), poly(1,5-dioxepan-2-one), polyvinylpyrrolidone (PVP), poly-p-dioxanone (PPDX) and their compounds and copolymers or mixtures thereof.

[0084] Polymer nanofibers preferably have a fiber diameter of less than one micrometer, preferably in the range of 300 to 2000 nm, and particularly in the range of 500 to 1000 nm. According to the present invention, the polymer nanofibers can also have a diameter of up to 3 micrometers.

[0085] Advantageous embodiments in this regard are described in EP 3 922 217 A1, to which full reference is hereby made.

[0086] The medicinal agent can preferably be embedded in a polymer, forming the medicinal agent layer, and wherein the medicinal agent is preferably an antiproliferative, e.g., sirolimus, or other Limus derivatives or paclitaxel (PTX), or a long-term stable depot progestogen, e.g., etonogestrel, levonorgestrel, or an antiprogesterone, e.g., mifepristone, or a spermicide, e.g., nonoxynol 9, or a cytostatic agent, e.g., mitomycin, capecitabine, or methotrexate (MTX).

[0087] The functional sleeve can have a smaller cross-section at a proximal and / or a distal end than the rest of the sleeve, preferably with a proximal and / or a distal tapered section being provided that is approximately conical in shape.

[0088] By reducing the cross-section of the functional sleeve, it can be secured against slipping on the balloon.

[0089] Conventional balloons tend to expand excessively in their distal and proximal sections ("dogbone") during inflation, which can cause particular trauma to the vessel wall in these areas. Therefore, in the embodiments of the balloon catheter device according to the invention, it is advantageous to omit window- or slot-shaped openings in the functional sleeve in the sections immediately adjacent to the balloon shoulders, proximally and distally, in order to prevent dogbone deformation of the balloon during inflation.

[0090] Furthermore, the functional sleeve can be connected to the catheter shaft of the balloon catheter via proximal and / or distal tab elements.

[0091] This also prevents slippage and, in particular, makes it easier to insert the sleeve into the balloon catheter.

[0092] The tubular functional sleeve can have a tangential and / or an axial support layer, wherein the tangential support layer is formed by polymer nanofibers with higher strength and / or by an additional polymer layer (e.g. by a laser-cut tubular, degradable polymer semi-finished product, or by a layer formed by melt electrospinning writing MEW) and / or that the functional sleeve has axial support struts arranged tangentially around the circumference and at equal intervals from each other, which are preferably arranged in the region of the inner fold lines outside the functional sleeve.

[0093] Such a structural design allows the stiffness of the functional sleeve to be adjusted or improved in the axial and tangential directions.

[0094] The coating of the balloon membrane by dip coating, as a sprayed-on polymer fleece, or as an encasing intermediate sleeve can exhibit adhesive properties.

[0095] The adhesive properties of the drug-containing polymer component promote adhesion to the wall of the hollow organ. Specifically, this means that the portions of the drug-containing layer pressed out through the opening of the functional sleeve adhere to the inner wall of a hollow organ when they unfold.

[0096] The sleeve can be bonded to the balloon membrane by means of a material bond, e.g. by spot gluing or polymer welding, with the connection points preferably being arranged on inner fold lines of the balloon membrane.

[0097] The functional sleeve is preferably made of a low-elasticity polymer whose elasticity is lower than that of the balloon membrane of the balloon.

[0098] The total area of ​​the passage opening, if designed as slots, can be at least 10 percent, at least 15 percent, or at least 20 percent up to a maximum of 50 percent, or 45 percent, or 40 percent, or a maximum of 35 percent, and in particular a maximum of 30 percent, of the total area of ​​the functional sleeve; or the total area of ​​the passage openings, if designed as window-like openings, can be at least 30 percent, or at least 35 percent, or at least 40 percent, or at least 45 percent, or at least 50 percent up to 85 percent, or a maximum of 80 percent, or 75 percent, or a maximum of 70 percent, of the total area of ​​the functional sleeve.

[0099] In addition, an outer protective cover can be arranged on the functional sleeve in its initial state.

[0100] This foil-like protective sleeve prevents contact with blood and thus avoids thrombus formation during insertion. At the implantation site, the protective sleeve can then be removed by pulling it back or by tearing it due to unfolding. Furthermore, the stability of the sleeve's fold for transport on the balloon catheter can be enhanced by an adhesive surface treatment of the sleeve's outer surface.

[0101] Furthermore, the invention provides a method for manufacturing a functional sleeve for a balloon catheter device described above. This method comprises the following steps: Blow molding of a tubular polymer blank in a tempered metallic mold to the diameter of an inner shell wall, demolding and cutting to length in the area of ​​sleeve shoulders, mounting the sleeve onto a holding core, which may also consist of an expandable wire mesh that can adapt to both the sleeve unfolding diameter and the smaller diameter of the sleeve shoulders, cutting, in particular laser cutting of through openings in the sleeve to form the functional sleeve.

[0102] Furthermore, the invention provides a method for manufacturing a balloon catheter device as described above. This method comprises the following steps: Applying a layer of medical drug to the outer shell of a preferably pre-folded balloon of a balloon catheter device while the balloon is inflated, applying (axially drawing up) a pre-folded functional sleeve onto / over the dried drug layer while the balloon is deflated, wherein the orientation is such that the folds of the balloon and sleeve lie within each other, joining the functional sleeve and the balloon (chemical, material-bonded connection: welding, gluing), uniformly folding and wrapping the balloon together with the functional sleeve around a longitudinal axis of the balloon catheter device for storage until use.

[0103] The application of the polymer gel solution to the balloon or to a cylindrical molded body (separate nonwoven fabric) can be done by spraying with an air jet (air spraying) or by spinning in an electric field (electrospinning) and / or by a combination of these (electrostatic air spraying) and / or by dipping in a solution (dip coating) and / or by applying a continuous strand of melt (melt electrospinning writing) or discontinuously by means of 3D printing.

[0104] In addition, a separating layer can be applied to the balloon membrane or to the carrier of the nonwoven fabric before the mixture is applied.

[0105] Providing a suitable separating layer later makes it easier to detach the active ingredient layer from the balloon membrane or the carrier.

[0106] The advantages of the methods according to the invention correspond analogously to the advantages that have been explained above with reference to the balloon catheter device according to the invention.

[0107] For all applications of the balloon catheter device according to the invention in hollow organs, atraumatic dilation of constrictions can be achieved through the cushion-shaped segmentation of the outer contour. Possible drug applications can be briefly summarized as follows, depending on the hollow organ application: For use in blood vessels, antiproliferatives such as Limus derivatives (e.g., sirolimus) or paclitaxel (PTX) are suitable as agents for delivery into the vessel wall to reduce excessive wall reaction (intimal hyperplasia). For application in the fallopian tube, agents with contraceptive effects are suitable, e.g., long-term stable depot progestins such as etonogestrel or levonorgestrel, or a suitable antiprogesterone such as mifepristone, or a spermicide such as nonoxynol. In principle, application with a contraceptive agent in the vas deferens is also possible. For the treatment of carcinomas in hollow organs, e.g., in the bile ducts, cytostatic agents such as mitomycin, capecitabine, or methotrexate (MTX) may be used.Other possible applications include other hollow organs such as the pancreatic duct, the urinary tract, lymphatic vessels such as the thoracic duct, the tracheobronchial system, the nasolacrimal duct, the Eustachian tube, or even the gastrointestinal tract.

[0108] Furthermore, medical and therapeutic procedures for the treatment of hollow organs with the balloon catheter device according to the invention are provided.

[0109] For use in blood vessels, the balloon catheter device according to the invention is intended to serve as a carrier for antiproliferatives such as Limus derivatives and thus ensure their transfer with longer-term contact to the vessel wall.

[0110] When used in blood vessels, Limus derivatives have a much more favorable biological effect than paclitaxel. However, they are difficult to transfer into the vessel wall with conventionally coated balloons via a single, brief balloon contact, as they adhere significantly less well than paclitaxel crystals, which are injected into the vessel wall. With the balloon catheter device according to the invention, the polymer drug layer is pressed onto or into the vessel wall as "gel spots" or "microflakes" through the openings of the functional sleeve.

[0111] When applying the balloon catheter device according to the invention to the fallopian tubes, contraceptive agents such as long-term stable depot progestins, e.g., etonogestrel, levonorgestrel, or a suitable antiprogesterone, e.g., mifepristone, or a spermicide, e.g., nonoxynol 9, can be used. In principle, application with a contraceptive agent to the vas deferens is also possible.

[0112] For the treatment of carcinomas in hollow organs, e.g. in the bile ducts, cytostatic agents such as mitomycin, capecitabine or methotrexate (MTX) can be provided as medical agents for the balloon catheter device according to the invention.

[0113] Other possible applications of the balloon catheter device include other hollow organs such as the pancreatic duct, the urinary tract, lymphatic vessels such as the thoracic duct, the tracheobronchial system, the nasolacrimal duct, the Eustachian tube, or the gastrointestinal tract.

[0114] The present invention will be described below with reference to several exemplary embodiments illustrated in the figures. These show in Figure 1 a schematic side view of a balloon catheter device according to a first embodiment of the invention, with window-like through-openings, Figure 2 a schematic lateral view of the balloon catheter device according to a second embodiment, with window-like through-openings and conically tapered sections at the proximal and distal ends, Figure 3a schematic side view of the balloon catheter device according to a third embodiment, with triangular window-like passage openings, Figure 4 a schematic lateral view of the balloon catheter device according to a fourth embodiment, with three rows of slots consisting of longitudinally extending axial slots and proximal and distal tab elements, Figure 5 a schematic lateral view of the balloon catheter device according to a fifth embodiment, with three rows of slots and a pattern of pores (perforations) (not shown) and conically tapered sections at the proximal and distal ends, Figure 6a schematic lateral view of the balloon catheter device according to a sixth embodiment according to the invention, with three rows of slots, conically tapered sections at the proximal and distal ends and axially extending support struts, Figure 7 a schematic lateral view of the balloon catheter device according to a sixth embodiment of the invention with a segmented structure of interconnected circumferential rings, Figure 8 a schematic representation of a folding pattern (pleating into 3 folds) of the functional sleeve, Figure 9 a schematic representation of one third of a circumferential segment, corresponding to the surface area of ​​a fold, in the unfolded state, Figure 10 another embodiment of one third of a circumferential segment, corresponding to the lateral surface of a fold, in the unwound state, Figure 11a schematic representation of a functional sleeve section with axially oriented slots of a functional sleeve, which allows a distinct cushion-like protrusion of an underlying balloon membrane upon expansion, Figure 12 a representation of a functional sleeve section with tangentially oriented slots of a functional sleeve, which allows a slight pre-bulging of an underlying balloon membrane upon expansion, Figure 13 another representation of a section-wise slot pattern of slots of a functional sleeve, Figure 14 another representation of a section-wise slot pattern of slots of a functional sleeve, Figure 15 a schematic representation of grouped axial slots and holes (pores) of the functional sleeve, Figure 16 a schematic representation of a combination of grouped axial slots and holes with intentional cracking between axially closely adjacent slots during balloon expansion, Figure 17a schematic top view of an advantageous embodiment of the functional sleeve of the balloon catheter device according to the invention, and Figure 18 a schematic representation of a balloon catheter device according to the invention with a functional sleeve according to Figure 17 .

[0115] A balloon catheter device 1 according to the invention is described in more detail below with reference to a first embodiment ( Figure 1 ).

[0116] The balloon catheter device 1 is designed for the atraumatic treatment of hollow organs and comprises a balloon catheter 2 (shown without proximal catheter shaft) with a balloon 3. A medical drug layer 4 is applied to an outer sheath wall of the balloon 3.

[0117] The medical agent layer 4 is designed as a coating of a balloon membrane of the balloon 3, wherein the medical agent is contained in a polymer gel formulation.

[0118] Alternatively, the medical drug layer 4 can be designed as a biodegradable polymer fleece sprayed onto the balloon membrane with compartments or microcompartments in which the medical drug is embedded.

[0119] Alternatively, the medical drug layer 4 can be designed as a tubular intermediate sleeve with a nonwoven structure made of biodegradable polymer with microcompartments or compartments in which the medical drug is embedded.

[0120] A functional sleeve 5 is arranged on the medical drug layer 4 or on the balloon 3 of the balloon catheter 2, which is connected to the balloon 3 of the balloon catheter 2.

[0121] The connection of the sleeve 5 to the balloon membrane or balloon 3 is, in particular, metallurgically bonded. The connection is achieved, for example, by spot welding, surface bonding, or by large-area adhesion of an active ingredient-containing gel between the balloon membrane and the functional sleeve. Spot or linear connections are preferably arranged along internal fold lines.

[0122] According to the first embodiment, the functional sleeve 5 is approximately tubular or cylindrical and made of a low-extensibility polymer.

[0123] The functional sleeve 5 has approximately rectangular through-openings 6, which are bounded by flat sections or flat struts 7.

[0124] It is provided that approximately the entire surface of the functional sleeve 5 has the through-opening 6, or that the through-opening 6 is arranged over almost the entire surface of the functional sleeve 5.

[0125] In an initial state, the functional sleeve 5 together with the medical active ingredient layer 4 and the balloon 3 is folded around a sleeve longitudinal axis, the folding being directed as pleating around a sleeve longitudinal axis and being unfoldable in a final state to lie against an inner wall of a hollow organ.

[0126] According to all embodiments, the passage openings have rounded corners.

[0127] Furthermore, the functional sleeve 5 has pores 20 in the area of ​​its struts 7 and on its entire shell wall (not shown in Figure 1 ) on.

[0128] The balloon catheter device 1 according to the invention will now be described in more detail using a second embodiment as an example ( Figure 2Unless otherwise described, the second embodiment, like the subsequent embodiments, essentially corresponds to the balloon catheter device 1 according to the first embodiment. Identical technical features are identified by the same reference numerals.

[0129] According to the second embodiment, the functional sleeve 5 of the balloon catheter device 1 has a smaller cross-section at a proximal and a distal end 8, 9 than the rest of the functional sleeve. These sections are referred to as the proximal and distal conical sections 10, 11. The proximal conical section 10 and the distal conical section 11 are designed to prevent axial displacement of the functional sleeve 5 on the balloon 3.

[0130] According to a third embodiment, the through-openings 6 are approximately triangular in shape ( Figure 3 ).

[0131] According to a fourth embodiment, the through-openings 6 are designed as slots extending in the axial direction, wherein in the present embodiment three rows of tangentially circumferential axial slots are provided ( Figure 4 ).

[0132] Furthermore, according to the fourth embodiment of the balloon catheter device, the functional sleeve 5 is connected to a catheter shaft 14 of the balloon catheter 2 via proximal and distal tab elements 12, 13.

[0133] In this way, the functional sleeve 5 is secured against slipping on the balloon 3 of the balloon catheter device 1. In addition, the tab elements 12, 13 facilitate the insertion of the functional sleeve 5 together with the balloon catheter 2 into a guide catheter or a sheath.

[0134] According to a fifth embodiment, which essentially corresponds to the fourth embodiment, the through-openings 6 are also designed in the form of axial slots, wherein the functional sleeve additionally comprises the proximal conical section 10 and the distal conical section 11 and has a pattern of pores (perforations; not shown) in the area of ​​the struts 7 ( Figure 5 ).

[0135] According to a sixth embodiment, which essentially corresponds to the fifth embodiment, the functional sleeve 5 has three axial struts 15 which extend axially over approximately the entire length of the functional sleeve 5 and are arranged tangentially around the circumference at approximately equal intervals from each other at an angle of approximately 120° ( Figure 6According to this embodiment, three axial support struts are provided to increase the stiffness of the functional sleeve in the axial direction. However, two, four, five, or more axial struts 15 can also be provided.

[0136] The through-openings designed as slots according to the fourth, fifth and sixth embodiments can be opened in the axial direction via predetermined breaking points 17 ( Fig. 16 ) are interconnected so that, during balloon expansion, several adjacent axial slots connect to form a common axial slot, allowing for greater cushion formation in this area.

[0137] According to a seventh embodiment, the through-openings 6 of the functional sleeve are designed in the form of tangentially circumferential recesses or slots, which, however, are interrupted at least once by axially extending struts 7.

[0138] As shown above, the technical features of the present invention with regard to the geometric or structural design of the through-openings 6, the struts 7, the conical sections 10, 11, the tab elements 12, 13, the axial struts or tangential struts or also an axial or a tangential support layer and the predetermined breaking points 17 can be combined with each other as desired, provided that this is technically possible and makes sense.

[0139] Various or different designs of the passage openings 6, insofar as these are designed as slots, are shown in the Figures 11 to 16 depicted.

[0140] Preferably, the slots extend only in the axial direction ( Figure 11 ).

[0141] However, the slots can also be inclined relative to the axial direction ( Figure 13 ).

[0142] Furthermore, the slots can also be wavy in shape ( Figure 14 ).

[0143] Furthermore, according to a less advantageous embodiment, the slits can also extend in the tangential direction, resulting in no significant cushion formation of an underlying, expanded balloon membrane ( Figure 12 ).

[0144] In the area of ​​the struts 7 and especially also in the area between the axial slots, pores 16 are arranged distributed over the entire outer wall of the functional sleeve 5 ( Figure 15 ).

[0145] According to such a design, the slots can also be shorter, whereby, for example, four axial slots can be connected to each other via predetermined tear points 17 when the balloon 3 expands ( Figure 16 ).

[0146] The balloon 3, the medical drug layer 4, and the functional sleeve 5 of the balloon catheter device 1 are folded or pleated around a longitudinal axis of the catheter in their initial state. For example, the folding process involves three equally sized, axially oriented folds evenly distributed around the circumference. The folds extend along a first fold line A and a second fold line B ( Figures 8 to 10 ).

[0147] The folds are evenly and uniformly wound around the longitudinal axis of the balloon catheter and attached to it.

[0148] Furthermore, the invention provides a method for manufacturing a functional sleeve for a balloon catheter device described above. This method comprises the following steps: Blow molding of a tubular polymer blank in a tempered metallic mold to the diameter of an inner shell wall, demolding and cutting to length in the area of ​​sleeve shoulders, mounting the sleeve onto a holding core, which may also consist of an expandable wire mesh that can adapt to both the sleeve unfolding diameter and the smaller diameter of the sleeve shoulders, cutting, in particular laser cutting of through openings in the sleeve to form the functional sleeve.

[0149] Furthermore, the invention provides a method for manufacturing a balloon catheter device as described above. This method comprises the following steps: Applying a medical drug layer to an outer shell wall of a preferably pre-folded balloon of a balloon catheter device in the expanded state of the balloon, applying (axially drawing up) a pre-folded functional sleeve onto / over the dried drug layer with the balloon deflated, wherein the orientation is such that the folds of balloon and sleeve lie within each other, joining the functional sleeve and the balloon (welding, gluing, adhesive drug layer), uniformly folding and wrapping the balloon together with the functional sleeve around a longitudinal axis of the balloon catheter device for storage until use and for transport to the site of action.

[0150] The application of the polymer gel solution to the balloon or to a cylindrical molded body (separate nonwoven fabric) can be done by spraying with an air jet (air spraying) or by spinning in an electric field (electrospinning) and / or by a combination of these (electrostatic air spraying) and / or by dipping in a solution (dip coating) and / or by applying a continuous strand of melt (melt electrospinning writing) or discontinuously by means of 3D printing.

[0151] In addition, a separating layer can be applied to the balloon membrane or to the carrier of the nonwoven fabric before the mixture is applied.

[0152] Providing a suitable separating layer later makes it easier to detach the active ingredient layer from the balloon membrane or the nonwoven fabric from the carrier.

[0153] In the following, a preferred embodiment of a balloon catheter device 1 according to the invention for gentle, cushion-like balloon expansion of the hollow organ and simultaneous application of the active ingredient into the hollow organ wall is described in more detail ( Figure 17 Unless otherwise described, this balloon catheter device 1 has all the features of the balloon catheter devices described above. Identical technical features are identified by the same reference numerals.

[0154] This balloon catheter device 1 comprises the balloon catheter 2 with the balloon 3. A medical drug layer 4 is applied to the outer sheath of the balloon 3.

[0155] Furthermore, the functional sleeve 5 is arranged on the balloon catheter 2, wherein the functional sleeve 5 is connected to the balloon catheter 2 substantially along its entire length. This connection can be a distributed point connection, a planar connection, or a substantially planar connection.

[0156] A connection along connection points or lines of the welded membranes, produced by plastic, in particular polymer, welding, is preferred. Corresponding connection points or lines preferably lie on fold lines of the sleeve and the balloon, especially on inner fold lines.

[0157] The functional sleeve 5 has a higher stiffness than the balloon 3, or, with approximately the same wall thickness, a higher modulus of elasticity.

[0158] In the functional sleeve 5, axial sections 18 and tangential sections 19 are arranged alternately and spaced apart from each other in the longitudinal direction.

[0159] At a proximal end of the functional sleeve 5, one of the axial sections 18 is initially formed.

[0160] In the axial section 18, axial slots 20 extending tangentially or radially around the circumference and spaced approximately equally apart from one another in the axial direction are formed. The axial slots 20 have approximately the same length in the axial direction and are aligned with each other in the tangential direction.

[0161] The first axial section 18 is followed by a first tangential section 19.

[0162] The axial sections 18 are spaced apart from the tangential sections 19 in the longitudinal direction.

[0163] In the tangential section 19, several tangential slots 21 extending transversely to the longitudinal direction or extending tangentially are formed. The tangential slots 21 are arranged at equal intervals from each other in the axial direction and extend tangentially or radially circumferentially over the outer wall of the functional sleeve 5.

[0164] The balloon 3 of the balloon catheter 2 and the functional sleeve 5 connected to it are folded and pleated together around a longitudinal axis of the balloon catheter device 1.

[0165] For the atraumatic treatment of hollow organs, it is then intended to position the balloon catheter device 1 in the area of ​​a hollow organ to be treated.

[0166] Then the balloon 3 of the balloon catheter 2 is expanded, so that the balloon 3 unfolds together with the associated functional sleeve 5.

[0167] Subsequently, the hollow organ expands with cushion formation of the balloon membrane of balloon 3 in the area of ​​the tangential slits 21. In the area of ​​the axial slits 20 and the tangential slits 21, an active ingredient is then applied to an inner lining wall of the hollow organ.

[0168] After completion of the hollow organ dilation and drug application, the balloon 3 of the balloon catheter 2 is deflated, whereby the balloon 3 and the functional sleeve 5 fold back together along predetermined fold lines that were previously created during folding and pleating. The balloon catheter device 1 can then be removed from the human body.

[0169] It is also possible for the functional sleeve 5 to have pores across essentially its entire surface. The medical agent can also be applied through these pores.

[0170] According to the present embodiment, five axial sections 18 are arranged at a proximal and a distal end of the functional sleeve. In total, four axial sections 18 are provided according to this embodiment, with three tangential sections 19 arranged between and spaced apart from the axial sections 18.

[0171] All embodiments and exemplary embodiments of the balloon catheter device according to the invention can be combined with each other as desired, provided that this is technically sensible and possible. Reference symbol list

[0172] 1 Balloon catheter device 2 Balloon catheter 3 Balloon 4 Medical drug layer 5 Functional sleeve 6 Through-holes 7 Struts 8 Proximal end 9 Distal end 10 Proximal conical section 11 Distal conical section 12 Proximal tab elements 13 Distal tab elements 14 Catheter shaft 15 Axial struts 16 Pores 17 Tear points 18 Axial section 19 Tangential section 20 Axial slot 21 Tangential slot

Claims

1. A balloon catheter device (1) for the atraumatic dilation of hollow organs, comprising a balloon catheter (2) with a balloon (3), a tubular functional sleeve (5) applied to the balloon (3) for the directional, segmented, cushion-like unfolding of the balloon (3), wherein the functional sleeve (5) is folded in an initial state together with the balloon (3) about a longitudinal axis of the sleeve, wherein the folding of the functional sleeve (5) is directed as a pleating about a sleeve longitudinal axis and is unfoldable in a final state for abutting against an inner wall of a hollow organ, and wherein the tubular functional sleeve (5) has planar sections and / or planar struts (7) which delimit through-openings (6), characterized in that the functional sleeve (5) is configured to sectionally confine an expansion of the balloon (3), wherein the functional sleeve (5) is connected to the balloon (3) in the region of the planar sections and / or the planar struts (7).

2. The balloon catheter device (1) according to claim 1, characterized in that the functional sleeve (5) is formed from a polymer with low stretchability, the stretchablility of which is lower than the stretchability of the balloon membrane of the balloon (3).

3. The balloon catheter device (1) according to claim 1 or 2, characterized in that the sleeve (5) has a diameter that corresponds approximately to the diameter of the expanded balloon.

4. A balloon catheter device (1) according to any one of claims 1 through 3, characterized in that the connection of the sleeve (5) to the balloon membrane is made, for example, by spot polymer welding or gluing, wherein the connection points are preferably located on inner folding lines, or by surface adhesion of an active-ingredient-containing adhesive gel between the balloon membrane and the functional sheath, wherein the connection between the balloon and the sleeve is preferably achieved by the adhesion of an active-ingredient-containing adhesive layer arranged between the balloon and the functional sleeve, wherein additionally and / or alternatively a spot and / or linear connection by laser welding, or a planar connection by adhesive bonding, in particular a connection over all planar surfaces or struts, is provided.

5. A balloon catheter device (1) according to any one of claims 1 through 4, characterized in that the through-openings (6) are formed as slits, in particular laser-cut slits, wherein these slits have a preferably axially oriented sinusoidal configuration.

6. A balloon catheter device (1) according to any one of claims 1 through 4, characterized in that the through-openings (6) are formed as, in particular, laser-cut slits, wherein in the functional sleeve (5), sections with axial slits, referred to as axial sections, and sections with tangential slits, referred to as tangential sections, are formed alternately in the axial direction of the functional sleeve, and wherein the axial sections and the tangential sections are arranged spaced from one another.

7. The balloon catheter device (1) according to claim 6, characterized in that alternately arranged axial sections with corresponding axial slits and tangential sections with corresponding tangential slits are provided which results in a constant or essentially uniform widening of the diameter of the sleeve and the balloon in a radial direction.

8. The balloon catheter device (1) according to claim 6 or 7, characterized in that the tangential sections form decoupling sections between the axial sections in order to provide an approximately constant diameter in the radial direction over a substantially entire length of the device in the axial direction, so that the device can be expanded substantially cylindrically in the axial direction.

9. The balloon catheter device (1) according to any one of claims 6 through 8, characterized in that the alternately arranged axial sections and tangential sections are formed and arranged at a distance from one another in an axial direction in such that they do not overlap one another, and / or that the axial slits of the axial sections and the tangential slits of the tangential sections are formed and arranged in such that they do not overlap one another in the tangential direction and / or the decoupling sections formed by the tangential sections cause a constriction of the balloon diameter in these areas so that a substantially constant diameter is provided in the axial sections, resulting in a substantially uniform distribution of forces in the radial direction towards the outside during unfolding.

10. The balloon catheter device (1) according to any one of claims 1 through 9, characterized in that a medical active substance layer (4) containing a medical active substance is arranged between the functional sleeve (5) and the balloon (3), wherein the medical active substance layer (4) is formed as a coating of the balloon membrane formed from a polymer gel, in particular a biodegradable polymer gel, and a medical active substance, so that the medical active substance is contained in a polymer gel formulation, and / or a polymer non-woven applied onto the balloon membrane, in particular a biodegradable polymer non-woven with the medical active ingredient, and / or as a tubular intermediate sleeve with a non-woven structure made of, in particular biodegradable polymer and the medical active ingredient, so that the functional sleeve (5) is designed to provide protection of the active ingredient layer arranged under the functional sleeve (5) and forms a second functional area for releasing the active ingredient in the region of the through-openings (6).

11. The balloon catheter device (1) according to claim 10, characterized in that the medical active ingredient is preferably incorporated in a polymer of the medical active ingredient layer (4), and wherein the active medical ingredient is preferably an antiproliferative, e.g. sirolimus, or other limus derivatives, or paclitaxel (PTX), or a long-term stable depot progestogen, e.g. etonogestrel, levonorgestrel, or an antiprogesterone, e.g. mifepristone, or a spermicide, e.g. nonoxinol 9, or a cytostatic agent, mitomycin, capecitabine or methotrexate (MTX).

12. The balloon catheter device (1) according to any one of claims 1 through 11, characterized in that the entire functional sleeve (5), and thus the planar struts (7) forming the functional sleeve, have pores (16), so that the functional sleeve (5) forms the second functional area for active substance release over its entire circumferential wall.

13. The balloon catheter device (1) according to any one of claims 1 through 12, characterized in that the sleeve is unfoldable and foldable together with the balloon membrane.

14. A method for manufacturing a functional sleeve (5) for a balloon catheter device (1) according to any one of claims 1 through 13, comprising the following steps in chronological order: - blow molding of a tubular polymer blank in a temperature-controlled metal mold to the diameter of the inner wall, - demolding and cutting to length in the area of the sleeve shoulders, - mounting the sleeve onto an expandable and / or compressible holding mandrel, - cutting, in particular laser cutting, of through-openings (6) in the sleeve to form the functional sleeve (5).

15. A method according to claim 14 for manufacturing a balloon catheter device (1) according to any one of claims 1 through 13, comprising the following steps: - applying a medical active substance layer (4) to an outer circumferential wall of a preferably pre-folded balloon (3) of a balloon catheter device (1) in the expanded state of the balloon (3), - applying a pre-folded functional sleeve (5) onto / over the dried active substance layer (4) with the balloon deflated, so that the folds of the balloon (3) and sleeve (5) lie inside each other, - connecting the functional sleeve (5) and the balloon (3), - uniform folding and wrapping of the balloon (3) together with the functional sleeve (5) around a longitudinal axis of the balloon catheter device (1) for storage and, when applied, for transportation to the site of action.