Balloon catheter with flexible retention element with coated and uncoated section

Abstract

The invention relates to a balloon catheter (1) for transurethral use, comprising an at least single-lumen catheter shaft (4) with an inflation lumen and an inflatable balloon (5), wherein the balloon (5) is connected to the distal end of the inflation lumen in a fluid-permeable manner, and a flexible distal shaft (7) arranged distal to the balloon (5) as well as a distal tip (9), wherein the balloon catheter (1) comprises precisely one flexible retaining element (6), and wherein the flexible retaining element (6) is provided so as to be axially displaceable along the balloon (5) and is suitable for dividing the balloon (5) into a distal (5d) and a proximal (5p) section, and wherein the proximal balloon section (5p) is coated with a medication, and wherein the distal balloon section (5d) is not coated with a medication, and wherein a placement aid (10) is provided on the balloon catheter (1),The placement aid (10) is tubular at least in the region of the balloon (5), and the tubular section has a length at least equal to the length of the balloon (5). The balloon catheter according to the invention allows the conservative treatment of benign prostatic hyperplasia without the use of additional imaging techniques.

Description

[0001] The invention relates to a balloon catheter, in particular for the treatment of benign prostatic hyperplasia, wherein the balloon of the balloon catheter can be divided into several sections by at least one flexible retaining element.

[0002] Balloon catheters are used in a wide variety of medical applications. They are generally characterized by the presence of an inflatable balloon, which is usually inflated by a fluid medium once inside the patient's body.

[0003] The balloon can be used to expand certain parts of the body, for example to treat narrowed blood vessels, but it can also be used to transfer and deliver medication.

[0004] Balloons in balloon catheters can come in a wide variety of shapes. Balloons with constrictions at specific points are particularly suitable for certain applications. For example, the balloon is made of materials that are less easy to inflate or is connected to the catheter shaft at these points.

[0005] The disadvantage of these balloons is that the constriction is part of the balloon and thus fixed in a specific location. Depending on the balloon's intended use and the anatomy of the area to be treated, it may be useful to individually adjust the constriction and thus divide the balloon into several sections. This is not possible with conventional balloons with a fixed constriction.

[0006] Such constricted balloons are used, among other things, to treat benign prostatic hyperplasia. Benign prostatic hyperplasia is a noncancerous enlargement of the prostate gland. In its early stages, this can be treated with medication with relatively good success.

[0007] DE 10 2013 219 509 A1 relates to a balloon catheter with an expandable balloon and a non-expandable cuff which, when located between the longitudinal ends of the balloon, can divide the balloon into several balloon sections because it prevents the part of the balloon it encompasses from expanding.

[0008] WO 2020 / 172560 A1 relates to a balloon catheter for treating benign prostatic hyperplasia comprising a balloon and a coating layer disposed on an outer surface of the balloon, wherein the coating layer contains an initial drug load of a therapeutic agent.

[0009] The known balloon catheters for treating benign prostatic hyperplasia have several disadvantages. First, the constriction within the balloon is fixed and cannot be adjusted to the individual needs and anatomy of the patient. This does not ensure optimal drug delivery, as the drug-coated portion of the balloon cannot be adjusted to the size of the prostate being treated.

[0010] Accordingly, the medication is either delivered to an area that is too small, which does not ensure complete treatment of the affected region, or to an area that is too large, which impairs or even destroys healthy tissue and, in the worst case, functional tissue such as the internal and / or external anal sphincter in the prostate area.

[0011] Furthermore, existing catheters for the treatment of benign prostatic hyperplasia lack a protective mechanism that would prevent premature release of medication from the balloon during placement in the urethra. This not only leads to uncontrolled drug release in the urethra, but also makes administering painkillers, for example, into the urethra before and during treatment critical, as this would only cause more medication to be washed out of the balloon catheter.

[0012] Accordingly, it is the object of the invention to provide a balloon catheter on whose balloon constrictions and thus balloon sections can be flexibly arranged.

[0013] Furthermore, it is an object of the invention to provide a balloon catheter for the treatment of benign prostatic hyperplasia which does not have the aforementioned disadvantages.

[0014] This object is achieved by an invention having the features of claim 1. Advantageous embodiments are the subject of the dependent claims.

[0015] The urethral balloon catheter according to the invention, hereinafter also referred to as balloon catheter for simplification, is intended for transurethral use and comprises an at least single-lumen catheter shaft with an inflation lumen and an inflatable balloon, wherein the balloon is connected to the distal end of the inflation lumen in a fluid-permeable manner.

[0016] Optionally, the urethral balloon catheter comprises at least a double-lumen catheter shaft with an inflation lumen and a drainage lumen.

[0017] The urethral balloon catheter according to the invention further comprises a flexible distal shaft arranged distally of the balloon and a distal tip.

[0018] Optionally, the distal shaft includes a thickened section located proximally at the tip.

[0019] In designs with at least a double-lumen shaft with a drainage lumen, the distal end of the drainage lumen for draining urine ends open at the tip, preferably radially outward, when the tip of the flexible shaft enters the filled bladder. This allows the attending physician to determine that the distal tip has reached the bladder based on the discharge of urine.

[0020] According to the invention, the balloon of the balloon catheter can be divided into two sections by precisely one flexible retaining element. The retaining element is defined as a flexible retaining element in that it is axially displaceable along the balloon and is not permanently or permanently connected to the balloon. Rather, the retaining element is merely arranged around the balloon in a form-fitting manner.

[0021] A balloon catheter according to the invention for transurethral use accordingly comprises at least a single-lumen catheter shaft with an inflation lumen and an inflatable balloon, wherein the balloon is connected to the distal end of the inflation lumen in a fluid-permeable manner, and a flexible distal shaft arranged distally of the balloon as well as a distal tip, wherein the balloon catheter further comprises exactly one flexible retaining element, wherein the one flexible retaining element is provided so as to be axially displaceable along the balloon and is suitable for dividing the balloon into a distal and a proximal section, and wherein a placement aid is provided on the balloon catheter, wherein the placement aid is provided in a tubular manner at least in the region of the balloon and wherein the tubular section has at least the length of the balloon with regard to its length.

[0022] According to the invention, the balloon catheter comprises exactly one retaining element, wherein the exactly one retaining element divides the balloon into a distal and a proximal section and wherein the proximal balloon section is coated with a drug and wherein the distal balloon section is not coated with a drug.

[0023] The retaining element is preferably made of a biocompatible material commonly used in the manufacture of balloon catheters, particularly PTF or PTFE. The material must be tear-resistant, as the balloon should not expand, or not expand significantly, in the area of ​​the retaining element during inflation. The maximum expansion of the balloon in the area of ​​the retaining element is 0 to 50%, preferably 0 to 30%, more preferably 0 to 20%, and especially 0 to 10% of the nominal diameter of the inflated balloon.

[0024] The retaining element is provided in the form of a ring or tube with a length of 0.1 to 3.0 cm, preferably 0.1 to 2.0 cm and in particular 0.1 to 1.0 cm.

[0025] If a single retaining element is provided on the balloon of the balloon catheter, the retaining element divides the balloon catheter into a first and a second or a proximal and a distal section.

[0026] The part of the urethral balloon catheter comprising the catheter shaft and the proximal balloon section will hereinafter also be referred to as the proximal catheter region.

[0027] The part of the urethral balloon catheter comprising the distal shaft with an optionally thickened section as well as a distal tip and the distal section of the balloon shall hereinafter also be referred to as the distal catheter region.

[0028] The proximal balloon section formed by the retaining element is usually coated with a drug. The distal balloon section formed by the retaining element is usually not coated with a drug and serves as an uncoated pilot balloon.

[0029] The retaining element can also serve to create a defined boundary between coated and uncoated balloon sections.

[0030] It may be useful to equip at least some sections of the balloon with radiopaque markers for visualization in imaging techniques, especially angiography.

[0031] It is particularly advantageous to equip the distal balloon section with at least one such marker, especially if the balloon catheter is intended as a urethral catheter for the treatment of benign prostatic hyperplasia. This allows the treating physician to determine, even in the X-ray image, when the distal balloon section is located within the patient's bladder. This is important for the application of a urethral catheter according to the invention, which will be described in more detail later.

[0032] It is also advantageous to equip the proximal balloon section with at least one such marker, especially if the balloon catheter is intended as a urethral catheter for the treatment of benign prostatic hyperplasia. This allows the treating physician to determine, even in the X-ray image, when the proximal balloon section is located in the area of ​​the patient's prostate. For this purpose, two markers can be provided, in particular, to mark the beginning and end of the coating. This is important for the application of a urethral catheter according to the invention, which will be described in more detail later.

[0033] "Proximal" refers to the area along the catheter that points toward the user, and "distal" refers to the area along the catheter that points away from the user. The position of the catheter tip is correspondingly distal. A "forward" movement thus indicates a distal movement, and a backward movement a proximal movement. Further positional relationships are evident from the figures.

[0034] The urethral balloon catheter according to the invention further comprises a placement aid which is provided at least in the proximal region and has a tubular section in the region of the balloon, wherein the tubular section preferably has at least the length of the proximal balloon section with regard to its length.

[0035] If the urethral catheter is divided into a distal and a proximal section by a single retaining element, the placement aid preferably extends from the proximal end to this single retaining element. However, embodiments are also conceivable in which the placement aid covers the entire balloon area, including all balloon sections formed by the various retaining elements.

[0036] Accordingly, the inner diameter of the placement aid is preferably larger than the inner diameter of the retaining element and thus the form fit of the retaining element is stronger than the form fit of the placement aid.

[0037] The urethral balloon catheter is accordingly arranged at least partially, namely at least with the proximal balloon section, within the distal tubular section of the placement aid.

[0038] The placement aid is designed to be retractable or displaceable along the balloon catheter, particularly proximally, in order to initially cover the entire proximal balloon section of the balloon catheter in different positions.

[0039] If the placement aid is pulled so far proximally that the proximal balloon section is no longer positioned within the placement aid or the placement aid no longer hinders the inflation of the balloon, this corresponds to a complete retraction of the placement aid.

[0040] If the placement aid covers the entire balloon or only the corresponding proximal balloon section, for example, these parts of the balloon cannot be inflated with proper pressurization. If the placement aid only covers a proximal portion of the balloon, only the distal section of the balloon can be inflated with proper pressurization. If the placement aid does not cover the balloon, the balloon can be inflated over its entire length, with the exception of the retaining element, with proper pressurization.

[0041] Accordingly, only the distal portion of the balloon can expand upon inflation if the placement aid covers the proximal portion of the balloon.

[0042] Accordingly, at least the tubular section of the placement aid that covers the balloon of the balloon catheter or parts thereof is designed to be dimensionally stable (non-compliant) so that it can withstand application-specific pressurization and prevents inflation of the balloon in this area.

[0043] Distally, the placement aid preferably extends to the retention element or across the entire balloon of the balloon catheter, but not beyond the thickened portion of the shaft or even to the distal tip. The placement aid preferably ends distally, at the latest, before the proximal end of the distal shaft.

[0044] Proximally, the placement aid extends so far that the proximal end of the placement aid is still outside the urethra even when the urethral balloon catheter has been inserted or placed into the urethra as intended, and thus the proximal end of the placement aid can be grasped by the user in order to be able to gradually withdraw the placement aid proximally from the balloon of the urethral catheter.

[0045] The placement aid also serves to protect the coated portion of the balloon from loss of the coating. Especially when coated with medication, the medication should be released only at the target site, such as the prostate.

[0046] A handle element can optionally be provided at the proximal end of the placement aid to allow easy gripping and retraction of the placement aid.

[0047] Likewise, a marker element may be provided at the proximal end of the urethral balloon catheter and / or at the proximal end of the placement aid to indicate to the user the exact distal position of the placement aid.

[0048] This marking element can, for example, comprise a number of individual markers at the proximal end of the urethral balloon catheter and / or at the proximal end of the placement aid, wherein, for example, the first marker indicates the position of the placement aid in which the balloon is completely within the placement aid, the second marker indicates the position of the placement aid in which only the distal portion of the balloon is outside the placement aid, and the third marker indicates the position of the placement aid in which the balloon is completely outside the placement aid. Additional markers can be used to represent additional positions of the placement aid.

[0049] Preferably, the placement aid is formed entirely from its distal to its proximal end by a tubular, preferably flexible element.

[0050] However, embodiments of the placement aid are also conceivable in which only certain sections of the placement aid are provided in a tubular shape, but other sections are formed, for example, by connecting elements such as threads, bands or similar elements.

[0051] For example, it is conceivable for the placement aid to comprise only a tubular section distally, in which the balloon of the balloon catheter is arranged. Connecting elements can be provided proximally, by means of which the distal tubular section can be gradually retracted. Embodiments in which tubular sections and connecting elements alternate along the length of the placement aid are also conceivable.

[0052] Preferably, the placement aid is made of a low-friction material, particularly polytetrafluoroethylene (PTFE) or expanded polytetrafluoroethylene (ePTFE). This low-friction material simplifies both the advancement of the urethral balloon catheter according to the invention through the urethra and the gradual retraction of the placement aid during placement and treatment.

[0053] The inflation lumen extends from the proximal end of the urethral balloon catheter to the inflatable balloon. The optional drainage lumen extends from the proximal end of the urethral balloon catheter to the tip of the distal shaft.

[0054] To secure the distal shaft to the rest of the balloon catheter, a projection made of polyamide or a similarly robust and rigid material, such as that used for the balloon, is provided on the part of the balloon catheter distal to the balloon. The distal shaft can be secured to this projection. Accordingly, the projection itself and the proximal portion of the distal shaft overlap in the area of ​​the projection.

[0055] The extension continues the drainage lumen of the catheter shaft, and the distal shaft also includes a corresponding drainage lumen which, when attached to the extension, continues the drainage lumen of the catheter shaft.

[0056] The balloon can be coated, at least partially and preferably only in certain sections formed by the retaining element(s), with one or more medications. The medication is preferably a cytostatic or antiproliferative medication, for example, paclitaxel or sirolimus. The medication is preferably paclitaxel. However, the possible applications are not limited to the medications mentioned, but include all medications that can be administered via a balloon catheter.

[0057] The balloon is designed to be inflatable and can be reversibly converted from a compressed state to an expanded or dilated state by inflation. Deflation converts the balloon to the compressed or contracted state. The balloon is preferably made of a polyamide such as nylon (polyhexamethylene adipamide); a block copolymer of polyamides, polyethers, and polyesters; polyesters, polyurethanes, and / or polyolefins.

[0058] By expanding the coated balloon section, the drug, especially paclitaxel, is applied to the urethra and diffuses to the prostate, which inhibits the cell proliferation of the corresponding prostate cells and thereby treats the hyperplasia.

[0059] The distal shaft comprises a relatively soft distal tip, which is made of silicone, for example, and can be coated with polytetrafluoroethylene, hydrogel, or a silicone elastomer for lubrication.

[0060] The tip may have a larger diameter at a thickening than the other areas of the balloon catheter.

[0061] The distal portion is preferably 2 to 7, and especially 3 to 5 cm long, with the tip thereof 1 to 4, and preferably 2 to 3 cm long. The outer diameter of the distal shaft, and especially of the distal tip, may be 6 to 8 French (2 to 2.667 mm); the catheter shaft may have an outer diameter of 3 to 6, and especially 4 to 5 French.

[0062] The distal shaft or distal tip is preferably made of silicone, the catheter shaft is preferably made of polyamide.

[0063] At the distal tip, there is optionally at least one opening through which the optional drainage lumen opens to the outside. The optional at least one opening is preferably located laterally in the distal region of the tip, i.e., in the radial direction. This ensures that urine flow through the drainage lumen can only be detected once it reaches the bladder. However, the at least one opening can also be arranged at the end, i.e., in the axial direction.

[0064] For treatment, the attending physician can advance the urethral balloon catheter according to the invention into the urethra until at least the distal portion of the balloon, i.e., the uncoated pilot balloon, is located in the bladder. For further placement of the balloon, the distal portion of the balloon can now be inflated by applying pressure as directed and then retracted to the entrance of the bladder.

[0065] Now the proximal part of the balloon is in the area of ​​the prostate and can also be inflated after the placement aid has been removed or retracted.

[0066] After sufficient time for drug delivery, the balloon can be deflated and removed from the urethra and bladder.

[0067] The invention also includes a method for treating benign prostatic hyperplasia using a urethral balloon catheter according to the invention with a retaining element forming a distal balloon portion and a proximal balloon portion, wherein the proximal balloon portion is coated with a drug, comprising the following steps: (A) Providing a urethral balloon catheter according to the invention, wherein the placement aid rests against the proximal end of the retaining element; (B) Optional anesthesia of the urethra by injecting a local anesthetic into the urethra; (C) Insertion of the urethral catheter into the urethra of a patient requiring treatment for benign prostatic hyperplasia; (D) Advance the urethral catheter into the urethra and, if necessary, further lubricate the catheter tip by introducing a suitable fluid through the optional drainage lumen; (E) Place the urethral catheter by advancing the catheter into the urethra to a point where the distal balloon portion lies within the bladder; (F) Optional X-ray control of the catheter position if a radiopaque marker is provided in the distal balloon section; (G) inflating the distal balloon portion to a pressure of 2 to 8 atm, preferably 2 to 4 atm, and more preferably 4 atm; (H) Retract the entire catheter so that the distal portion of the balloon lodges in and blocks the bladder outlet; (I) deflating the distal balloon portion to a residual pressure of 0.1 to 2 atm, preferably 0.2 to 1.5 atm, and more preferably 0.5 to 1.0 atm; (J) Retract the placement aid so that the proximal area of ​​the balloon is also exposed and is no longer covered by the placement aid; (K) Optional X-ray control of the catheter position, provided that at least one radiopaque marker is provided in the coated proximal balloon section; (L) inflating the balloon and thus also the now exposed proximal portion of the balloon with a pressure of 4 to 20 atm, preferably 6 to 14 atm and in particular 8 to 10 atm; (M) Maintaining the catheter in the inflated state until sufficient drug delivery is achieved, which may take 1 to 15 minutes, 4 to 12 minutes, and especially 8 to 10 minutes; (N) deflation of the balloon; (O) If necessary, repeat steps (L) to (N) once or several times until sufficient drug release is achieved; (P) Removal of the urethral catheter with deflated balloon by completely withdrawing the urethral catheter from the urethra.

[0068] Furthermore, the invention also encompasses the use of the catheter according to the invention for the transurethral treatment of benign prostatic hyperplasia, such as in the method described above.

[0069] The urethral balloon catheter according to the invention overcomes the disadvantages of conventional balloon catheters for the treatment of benign prostatic hyperplasia.

[0070] The flexible retention element allows the attending physician to individually adjust the relative sizes of the balloon sections. No, or at least only a few, different balloon sizes need to be kept on hand.

[0071] Another advantage over conventional urethral catheters is that the treatment can be performed on an outpatient basis, for example, using lidocaine as a local anesthetic, without the need for a complex, X-ray-equipped catheter laboratory. Unlike other radiological interventions, X-ray monitoring of catheter placement is only optional, as correct placement is achieved by partially expanding the balloon and thus securing the balloon catheter in the bladder outlet.

[0072] Additionally, if a drainage lumen is present, the urine flowing out when the distal tip penetrates the bladder can indicate that the bladder has been reached. If necessary, additional ultrasound guidance provides further confidence during the procedure.

[0073] In particular, with the urethral balloon catheter according to the invention, the combination of the retaining element and the placement aid makes it possible to place the balloon very precisely in the area of ​​the prostate even without imaging techniques and thus achieve optimal drug transfer to the target area.

[0074] The invention and the technical environment are explained in more detail below using the figures as examples. It should be noted that the figures show a particularly preferred embodiment of the invention. However, the invention is not limited to the embodiment shown. In particular, the invention encompasses, to the extent technically feasible, any combination of the technical features listed in the claims or described in the description as relevant to the invention.

[0075] They show: Fig. 1 a urethral balloon catheter according to the invention with a pulled-up retaining element and adjacent placement aid in the inflated state. Fig. 2 the urethral balloon catheter according to the invention in the deflated state and ready for intervention. Fig. 3 the urethral balloon catheter according to the invention with partially inflated distal balloon section. Fig. 4 the urethral balloon catheter according to the invention with retracted placement aid, with inflated distal balloon section and partially inflated proximal balloon section. Fig. 5 the urethral balloon catheter according to the invention with retracted placement aid, with inflated distal balloon section and inflated proximal balloon section. Fig. 6 the urethral balloon catheter according to the invention with an offset retaining element for enlarging the distal balloon section.

[0076] Fig. Figure 1 shows a preferred embodiment of the urethral balloon catheter 1. For clarity, the balloon catheter 1 is shown in the inflated state. The balloon catheter 1 comprises a proximal region 2 and a distal region 3. The proximal region 2 comprises the at least single-lumen catheter shaft 4 (shown here in abbreviated form) with the inflation lumen and the optional drainage lumen (not shown), and the proximal portion of the balloon 5p coated with a drug. The distal region 3 comprises the distal portion of the balloon 5d, the distal shaft 7 with a distal thickening 8, and a distal tip 9 with preferably lateral openings (not shown).

[0077] The proximal and distal regions 2, 3 are defined by the retaining element 6, which divides the balloon 5 into a distal 5d and a proximal 5p section.

[0078] The placement aid 10 according to the invention is provided in the proximal region 2 of the urethral balloon catheter 1. It is preferably tubular and made of a low-friction material and preferably extends distally to the retaining element 6, preferably flush with it. In the inflated view, the placement aid 10, which also serves to protect the coating of the proximal balloon section 5p, is shown next to the catheter 1.

[0079] The inflation lumen and optional drainage lumen begin at the proximal end of the catheter shaft 4. Distally, the inflation lumen extends to the balloon 5 and is fluid-permeable to it for inflation and deflation. The drainage lumen ends distally with one or more openings, preferably on the side, in the area of ​​the distal tip 9.

[0080] Proximal to the distal tip 9, the distal shaft 7 preferably has a thickening 8 with a larger diameter than the rest of the shaft 7. The thickening 8 preferably has a larger diameter than the rest of the catheter 1 when the balloon 5 is compressed.

[0081] Fig. 2 shows the urethral balloon catheter 1 according to the invention according to Fig. 1 in the deflated state prior to use in an intervention. The distal balloon section 5d is deflated, as is the proximal balloon section 5p (not visible here within the placement aid 10). The flexible retaining element 6 is placed in the desired position, and the placement aid 10 is advanced to the proximal end of the retaining element 6.

[0082] Fig. 3 shows the urethral balloon catheter 1 according to the invention according to Fig. 2, wherein the distal balloon portion 5d is inflated. This state is achieved during placement of the catheter 1, when the distal region 3 lies within the bladder and the distal balloon portion 5d is inflated to fix the catheter 1 within the bladder.

[0083] Fig. 4 shows the urethral balloon catheter 1 according to the invention according to Fig. 3, wherein after placement, the placement aid 10 was retracted, releasing the proximal balloon section 5p. The proximal balloon section 5p is now also partially inflated. This state is achieved after placement of the catheter 1, after the distal balloon section 5d has been inflated to fix the catheter 1 within the bladder, and the drug delivery from the proximal balloon section 5p to the prostate can take place.

[0084] Fig. 5 shows the urethral balloon catheter 1 according to the invention according to Fig. 4, whereby the proximal balloon section 5p has now also been fully inflated for drug delivery. This state is achieved after placement of catheter 1 and optional verification of the position of the proximal balloon section 5p. The balloon now remains inflated for as long as necessary for sufficient drug delivery.

[0085] Fig. 6 shows the urethral balloon catheter 1 according to the invention in the state according to Fig. 4 but in an alternative arrangement of the flexible retaining element 6. The retaining element 6 is displaced further proximally on the balloon and arranged such that the distal balloon section is enlarged and the proximal balloon section is reduced. List of reference symbols 1 urethral balloon catheter 2 proximal area of ​​the urethral balloon catheter 3 distal area of ​​the urethral balloon catheter 4 Catheter shaft 5 balloon (5d: distal section; 5p: proximal section) 6 Retaining element 7 distal shaft 8 distal thickening 9 distal tip 10 Placement aid p proximal d distal

Claims

[1] Balloon catheter (1) for transurethral use with - a catheter shaft (4) with at least one lumen and an inflation lumen; and - an inflatable balloon (5), wherein the balloon (5) is fluid-permeable to the distal end of the inflation lumen; and - a flexible distal shaft (7) arranged distally of the balloon (5) and a distal tip (9); characterized byin that the balloon catheter (1) comprises precisely one flexible retaining element (6), wherein the flexible retaining element (6) is provided so as to be axially displaceable along the balloon (5) and is suitable for dividing the balloon (5) into a distal (5d) and a proximal (5p) section, and wherein the proximal balloon section (5p) is coated with a medicament and wherein the distal balloon section (5d) is not coated with a medicament, and wherein a placement aid (10) is provided on the balloon catheter (1), wherein the placement aid (10) is provided in a tubular manner at least in the region of the balloon (5), and wherein the tubular section has at least the length of the balloon (5) with regard to its length. [2] Balloon catheter according to claim 1, characterized bythat the catheter shaft (4) is provided with at least a double lumen with an inflation lumen and a drainage lumen, wherein the distal end of the drainage lumen ends open at the distal tip (9) for drainage of the urine when the tip (9) enters the filled urinary bladder. [3] Balloon catheter according to claim 2, characterized by that the distal end of the drainage lumen ends laterally open to the outside at the distal tip (9). [4] Balloon catheter according to one of the preceding claims, characterized by that the distal region (3) comprises a thickening (8) proximal to the distal tip (9). [5] Balloon catheter according to one of the preceding claims, characterized by that the placement aid (10) is made of a low-friction material, in particular PTFE or ePTFE. [6] Balloon catheter according to one of the preceding claims, characterized bythat the drug is a cytostatic or antiproliferative drug, in particular paclitaxel or sirolimus and preferably paclitaxel. [7] Balloon catheter according to one of the preceding claims, characterized by that the retaining element (6) is provided in a ring or tubular shape and is arranged in a form-fitting manner around the balloon (5) with a length of 0.1 to 3.0 cm, preferably from 0.1 to 2.0 cm and in particular from 0.1 to 1.0 cm. [8] Balloon catheter according to one of the preceding claims, characterized by that the distal balloon portion (5d) comprises at least one radiopaque marker. [9] Balloon catheter according to one of the preceding claims, characterized by that the proximal balloon section (5p) comprises at least one radiopaque marker, in particular two radiopaque markers, which mark the starting and end regions of the coating.

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