Balloon catheter

Abstract

This invention relates to a balloon catheter that allows for the aspiration of drug solution from outside the balloon catheter via a return channel. This ensures that the blocked target area maintains a high drug concentration, thereby reducing drug loss during delivery and perfusion, improving the efficiency of drug transfer to the target tissue, and reducing the risk of thrombosis.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a balloon catheter. Background Technology

[0002] Coronary heart disease (CHD) seriously affects human health. Data released in the "China Cardiovascular Disease Report 2016" in June 2017 showed that the prevalence and mortality rates of cardiovascular disease in my country are still on the rise, with an estimated 11 million people suffering from CHD. Drug-eluting stents are the preferred treatment for CHD and are widely used. However, increasing evidence suggests that drug-eluting balloons, when used in conjunction with other interventional procedures, offer advantages in certain situations. Drug-eluting balloons are a novel interventional treatment technique. The balloon attaches a drug that inhibits cell proliferation to its surface. By inflating the balloon, the drug is delivered to the affected area within the blood vessel wall to inhibit smooth muscle cell proliferation.

[0003] In clinical applications, a balloon is inflated at the narrowed area and held for a certain period of time. The medication coated on the balloon surface comes into contact with the blood vessel wall, thus transferring the drug to the vessel wall to exert its therapeutic effect. Drug-eluting balloons typically inflate for 30 to 60 seconds and must complete delivery within 25 minutes. Due to the very short contact time between the balloon surface medication and the blood vessel wall, drug transfer and utilization are limited, posing a challenge to the efficacy of drug-eluting balloons. Significant drug loss occurs during balloon delivery and inflation: approximately 10% to 25% of the drug is lost during vascular delivery, with about 1% to 10% actually transferred to the target tissue. After inflation, 60% to 70% enters the distal circulation, and 10% to 20% remains on the balloon.

[0004] Therefore, how to reduce the significant loss of drugs during delivery and improve the efficiency of drug transfer to tissues are problems that drug-eluting balloons need to address in the future. Summary of the Invention

[0005] The purpose of this invention is to provide a balloon catheter to solve the problems of significant drug loss during delivery and low drug transfer efficiency in existing drug-coated balloons.

[0006] To achieve the above objectives, according to one aspect of the present invention, a balloon catheter is provided, comprising a catheter body and a balloon, wherein the balloon comprises a first balloon, a second balloon and a third balloon, the first balloon, the second balloon and the third balloon being sequentially and spaced apart from the proximal end to the distal end of the catheter body along the axial direction of the catheter body;

[0007] The diameters of the first and third balloons after inflation are both larger than the diameter of the second balloon after inflation; the catheter body includes at least a fluid inlet channel and a fluid return channel that are isolated from each other; the fluid inlet channel is used to deliver fluid to the second balloon, and a plurality of micropores are formed on the surface of the second balloon for releasing the fluid; the distal end of the fluid return channel has at least one suction port, through which fluid around the second balloon is aspirated.

[0008] Optionally, at least one of the suction ports is located between the first balloon and the second balloon.

[0009] Optionally, the catheter body further includes a filling channel, which is isolated from the inlet channel and the return channel, respectively;

[0010] The inflation channel has at least one inflation port, which communicates with the first balloon to deliver an inflation medium to the first balloon through the inflation channel, thereby inflating the first balloon.

[0011] The inlet channel has at least two inlets, which are respectively connected to the second balloon and the third balloon, so as to deliver liquid to the second balloon and the third balloon through the inlet channel, causing the second balloon and the third balloon to inflate.

[0012] Optionally, the catheter body includes an outer tube and an inner tube; the outer tube includes an axially extending first inner lumen, a second inner lumen, and a third inner lumen, the first inner lumen being configured as the return fluid channel, the third inner lumen being configured as the filling channel, and the inner tube being configured as the inlet fluid channel;

[0013] The inner tube is inserted into the second inner lumen and extends beyond the distal end of the second inner lumen; the second balloon and the third balloon are fitted onto the distal end of the inner tube; the first balloon is fitted onto the outer tube.

[0014] Optionally, the catheter body includes an outer tube, an inner tube, and a suction catheter; the outer tube includes an axially extending first inner lumen, a second inner lumen, and a third inner lumen, the third inner lumen being configured as the filling channel, the inner tube being configured as the inlet channel, and the suction catheter being configured as the return channel;

[0015] The aspiration catheter is inserted into the first inner lumen and extends beyond the distal end of the first inner lumen; the inner tube is inserted into the second inner lumen and extends beyond the distal end of the second inner lumen; the second balloon and the third balloon are fitted onto the distal end of the inner tube; the first balloon is fitted onto the outer tube.

[0016] Optionally, the inlet channel has at least three inlets, which are respectively connected to the first balloon, the second balloon and the third balloon, so as to deliver drug solution to the first balloon, the second balloon and the third balloon through the inlet channel, so as to inflate the first balloon, the second balloon and the third balloon.

[0017] Optionally, the catheter body includes an outer tube and an inner tube, the outer tube including an axially extending first inner lumen and a second inner lumen, the first inner lumen being configured as the return fluid channel, and the inner tube being configured as the inlet fluid channel;

[0018] The inner tube is inserted into the second inner lumen and extends beyond the distal end of the second inner lumen; the second balloon and the third balloon are fitted onto the distal end of the inner tube; the first balloon is fitted onto the outer tube.

[0019] Optionally, the catheter body includes an outer tube, an inner tube, and a suction tube; the outer tube includes an axially extending first inner lumen and a second inner lumen, the suction tube is configured as the return fluid channel, and the inner tube is configured as the inlet fluid channel;

[0020] The aspiration catheter is inserted into the first inner lumen and extends beyond the distal end of the first inner lumen; the inner tube is inserted into the second inner lumen and extends beyond the distal end of the second inner lumen; the second balloon and the third balloon are fitted onto the distal end of the inner tube; the first balloon is fitted onto the outer tube.

[0021] Optionally, the second balloon is a single-layer balloon or a double-layer balloon; when the second balloon is a double-layer balloon, micropores are formed on the surface of the outer layer of the double-layer balloon, or, a number of micropores are formed on the surfaces of both the outer and inner layers of the double-layer balloon.

[0022] Optionally, the axial length of the first balloon after inflation is less than its radial height, and / or the axial length of the third balloon after inflation is less than its radial height.

[0023] Optionally, the first balloon and / or the third balloon are non-compliant balloons.

[0024] To achieve the above objectives, according to another aspect of the present invention, a balloon catheter is provided, comprising a catheter body and a balloon, the balloon comprising a proximal balloon and a distal balloon, the proximal balloon and the distal balloon being sequentially spaced on the catheter body from the proximal end to the distal end along the axial direction of the catheter body;

[0025] The catheter body includes at least a fluid inlet channel and a fluid return channel that are isolated from each other; the fluid inlet channel is used to deliver fluid; a plurality of micropores are formed on the surface of the distal balloon or the fluid inlet channel for releasing the fluid; the distal end of the fluid return channel has at least one aspiration port, through which fluid outside the balloon catheter is aspirated, and at least one aspiration port is located between the proximal balloon and the distal balloon.

[0026] Optionally, when a plurality of micropores are formed on the surface of the distal balloon, the distal balloon includes a proximal portion and a distal portion, the diameter of the distal portion after expansion is larger than the diameter of the proximal portion after expansion, and the micropores are located on the surface of the proximal portion.

[0027] Optionally, the axial length of the proximal balloon after inflation is less than its radial height.

[0028] Optionally, when a number of micropores are formed on the surface of the inlet channel, the axial length of the distal balloon after inflation is less than its radial height.

[0029] Optionally, the proximal balloon and / or the distal balloon are non-compliant balloons.

[0030] The balloon catheter provided by this invention has the following advantages:

[0031] The balloon catheter of this invention is primarily used for drug delivery. In practical use, the proximal and distal balloons can be inflated in the target area within the body, temporarily blocking blood flow. This allows the medication to enter the target area (such as a blood vessel) through micropores on the surface of the distal balloon or the inlet channel, achieving continuous drug perfusion. Furthermore, during infusion, the return channel on the catheter body continuously aspirates the medication from the blocked area, while new medication is continuously delivered to the inlet channel. This ensures a continuous flow of medication from the distal balloon or the micropores of the inlet channel into the blocked target area. This maintains a high concentration of medication within the blocked area, improving the efficiency of drug diffusion to the target tissue and reducing drug loss during delivery and perfusion. Simultaneously, the suction effect of the return channel within the blocked area creates fluid circulation, reducing the probability of thrombus formation and improving device safety. Moreover, by blocking the target area with proximal and distal balloons, the loss of drug solution flowing to both ends of the balloon is reduced, further improving the drug transfer efficiency.

[0032] The axial length of the proximal balloon (including the first balloon) and / or the distal balloon (including the third balloon) after inflation is preferably less than its radial height. This design can better solve the problem of vascular calcification lesions, because the shape of vascular calcification lesions is usually irregular. Conventional balloon shapes cannot fit well against the vessel wall of calcification lesions and cannot effectively block the diseased vessels. However, the proximal and distal balloons of the present invention can be disc-shaped after inflation, ensuring the adhesion between the balloon and the vessel wall and the occlusion effect. Attached Figure Description

[0033] Those skilled in the art will understand that the accompanying drawings are provided to better understand the invention and do not constitute any limitation on the scope of the invention. In the drawings:

[0034] Figure 1 This is a schematic diagram of an exemplary balloon catheter of the present invention, wherein the outer tube is a cross-sectional view;

[0035] Figure 2 yes Figure 1 A magnified view of a portion of the balloon catheter shown;

[0036] Figure 3 This is a schematic diagram illustrating the use of an exemplary balloon catheter of the present invention;

[0037] Figure 4 This is an end view of an exemplary outer tube of the present invention;

[0038] Figure 5 This is a partially enlarged view of an exemplary balloon catheter of the present invention;

[0039] Figure 6 This is a partially enlarged view of an exemplary balloon catheter of the present invention, wherein the first balloon is disc-shaped;

[0040] Figure 7 These are micrographs of the micropores provided in the experiments of this invention;

[0041] Figure 8 This is a comparison diagram of the immediate tissue drug concentration of a conventional drug-coated balloon and the balloon catheter of the present invention in the experiment of the present invention.

[0042] In the figure: balloon catheter 100; catheter body 110; outer tube 110a; inner tube 110b; aspiration catheter 110c; balloon 120; first balloon 121; second balloon 122; third balloon 123; micropore 124; inlet channel 111; return channel 112; filling channel 113; aspiration port 114; first lumen 115; second lumen 116; third lumen 117; blood vessel S.

[0043] The same or similar reference numerals in the accompanying drawings represent the same or similar parts. Detailed Implementation

[0044] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show components related to the present invention and are not drawn according to the actual number, shape, and size of components in the actual implementation. In the actual implementation, the type, quantity, and proportion of each component can be arbitrarily changed, and the component layout may also be more complex.

[0045] Furthermore, while each embodiment described below possesses one or more technical features, this does not imply that users of the present invention must simultaneously implement all technical features in any embodiment, or can only separately implement some or all technical features in different embodiments. In other words, provided it is feasible, those skilled in the art can, based on the disclosure of the present invention and depending on design specifications or implementation requirements, selectively implement some or all technical features in any embodiment, or selectively implement a combination of some or all technical features in multiple embodiments, thereby increasing the flexibility in implementing the present invention.

[0046] To make the objectives, advantages, and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention. As used in this specification, the singular forms “a,” “an,” and “the” include plural objects unless otherwise expressly indicated. As used in this specification, “a plurality of” generally means two or more unless otherwise expressly indicated. As used in this specification, the term “or” is generally used to include the meaning of “and / or” unless otherwise expressly indicated. The term “axial” generally refers to a direction parallel to the longitudinal axis of the balloon catheter; “proximal” generally refers to a direction closer to the balloon catheter operator; and “distal” refers to a direction farther from the balloon catheter operator. It should also be understood that reference numerals and / or letters are repeated in various embodiments of the present invention. This repetition is for simplicity and clarity and does not in itself indicate a relationship between the various embodiments and / or configurations discussed. It will also be understood that when an element is referred to as "connecting" another element, it can be directly connected to the other element, or there can be one or more intermediate elements.

[0047] The core idea of ​​this invention is to provide a balloon catheter, comprising a catheter body and a balloon. The balloon includes a first balloon, a second balloon, and a third balloon, which are sequentially spaced from proximal to distal along the axial direction of the catheter body. The inflated diameters of the first balloon and the third balloon are both larger than the inflated diameter of the second balloon. Furthermore, the catheter body includes at least two separate inlet and outlet channels, with the distal end of the outlet channel having at least one aspiration port. In actual use, after each balloon inflates within the target area, because the diameters of the first and third balloons are larger than that of the second balloon, they can block the target area at both ends of the second balloon, temporarily obstructing blood flow. Then, a liquid medication (containing a liquid drug) can be delivered to the second balloon through the inlet channel on the catheter body. Because the surface of the second balloon has several micropores, the medication inside will overflow from these micropores into the blocked target area under the pressure of the medication. Due to the drug concentration gradient, the medication diffuses to the target tissue and is absorbed by it. However, as the drug is transferred, the drug concentration in the target tissue increases, and the drug concentration gradient decreases. At this point, without intervention, the efficiency of drug diffusion to the target tissue will decrease. Therefore, during the infusion of the drug solution, it is also necessary to aspirate the drug solution around the second balloon (i.e., the drug solution within the target area) through at least one aspiration port at the distal end of the catheter body via the return channel. This allows new drug solution to be continuously injected into the target area through the micropores of the second balloon, maintaining a high concentration of drug solution within the target area. This increases the drug concentration gradient, helping the drug solution to continuously diffuse into the target tissue, thereby improving drug transfer efficiency. In particular, due to the aspiration effect of the return channel, the fluid circulation within the target area is promoted. Therefore, even if the target area is blocked, the risk of residual blood forming a thrombus can be reduced or avoided, improving the safety of device use. It should be understood that the target area here includes, but is not limited to, blood vessels. Furthermore, the balloon catheter of the present invention is not limited to delivering drug solutions; in other cases, it can also deliver other liquid substances, such as nanorobots. It should also be understood that the inflated diameters of the first and third balloons being larger than the inflated diameter of the second balloon includes the maximum inflated diameters of the first and third balloons being larger than the maximum inflated diameter of the second balloon.

[0048] In this invention, the distal end of the return channel has at least one aspiration port, preferably located between the first balloon and the second balloon. This facilitates the timely aspiration of medication from the periphery of the second balloon into the return channel through the proximal aspiration port, resulting in high aspiration efficiency, good aspiration effect, and simplified catheter structure with low manufacturing cost. It should also be understood that the second balloon can be a single-layer balloon or a double-layer balloon. When the second balloon is a double-layered balloon, there are two scenarios: First, several micropores are created only on the surface of the outer balloon, while the inner balloon has no micropores. The inner balloon is nested within the outer balloon, and an infusion chamber is formed between them. In this case, the entire balloon is inflated through the inner balloon, and the medication is delivered through the inlet channel to the infusion chamber between the inner and outer balloons, and then overflows into the target area through the micropores on the outer balloon. Second, several micropores are created on the surfaces of both the outer and inner balloons. The inner balloon is nested within the outer balloon, and an infusion chamber is also formed between them. In this case, the entire balloon is inflated through the inner balloon, and the medication is first infused into the inner balloon, then overflows into the outer balloon through the micropores on the inner balloon, and further overflows into the target area through the micropores on the outer balloon. It should be understood here that the term "micropore" in this invention refers to a hole with a size in the micrometer range, but the shape of the hole is not limited. Considering the ease of processing, the micropore is preferably a circular hole.

[0049] In this invention, the first, second, and third balloons are all made of non-compliant or semi-compliant materials, which expand to a specified size with increasing pressure and then cease to expand with further pressure. Furthermore, the use of non-compliant or semi-compliant materials avoids the second balloon from adhering to the blood vessel wall and hindering drug absorption, thus improving the absorption rate of the drug solution. For example, the materials used to prepare the balloons can be PEBAX (polyether block polyamide), polyethylene, or polyamide. The second balloon can be an angioplasty balloon or any other balloon used in interventional cardiovascular procedures, and its expansion is primarily achieved through drug infusion, while the first and third balloons can be expanded using conventional methods during percutaneous interventional procedures.

[0050] Furthermore, this invention does not limit the difference between the diameter of the second balloon after inflation and the diameters of the first and third balloons after inflation. Moreover, this invention does not limit the shape of the first, second, and third balloons after inflation; they can be spherical, elliptical, cylindrical, etc., with an elliptical shape being preferred. Preferably, the axial length of the first balloon after inflation is greater than its radial height, and / or the axial length of the third balloon after inflation is less than its radial height; for example, the first and / or third balloons are disc-shaped, to better address the problem of vascular calcification lesions.

[0051] This invention does not impose any particular requirements on the number and distribution of micropores on the second balloon; they can be uniformly or non-uniformly distributed. In a preferred embodiment, the micropores on the second balloon are uniformly arranged around the longitudinal axis of the second balloon, and are arranged in several layers along the longitudinal axis. When the second balloon is a single-layer balloon, the pore size preferably ranges from 5.0 μm to 500 μm, more preferably from 10 μm to 250 μm, and even more preferably from 10 μm to 50 μm. Furthermore, when the second balloon is a single-layer balloon, the number of micropores is preferably 5.0 to 100, more preferably from 5.0 to 50, and even more preferably from 5.0 to 25. It should be understood that the micropore size and number defined for a single-layer balloon also apply to the outer balloon in a double-layer balloon configuration.

[0052] Each balloon in this invention can be manufactured using a blow molding process, and the catheter body can be integrally formed or formed in parts. The catheter body can be a double-lumen tube, a triple-lumen tube, or a tube with more than one chamber. Furthermore, the balloon catheter of this invention is not limited to interventional blood vessels; it can be used in any human lumen, such as the esophagus, bile duct, uterus and its appendages, prostate, etc., where drugs or other substances need to be delivered for treatment.

[0053] The balloon catheter of the present invention will now be further described in conjunction with the accompanying drawings and preferred embodiments to better highlight the features and characteristics of the above embodiments. In the following description, it is assumed that the balloon catheter is used to deliver medication and treat cardiovascular diseases, thereby illustrating the features and characteristics achievable by the present invention, but this should not be construed as limiting the present invention.

[0054] Figure 1 This is a schematic diagram of the balloon catheter provided in a preferred embodiment of the present invention. Figure 2 yes Figure 1 A magnified view of a portion of the balloon catheter shown. Figures 1-2As shown, this embodiment provides a balloon catheter 100, which specifically includes a catheter body 110 and a balloon 120. The balloon 120 includes a first balloon 121, a second balloon 122, and a third balloon 123. The first balloon 121, the second balloon 122, and the third balloon 123 are sequentially and spaced apart on the catheter body 110 from the proximal end to the distal end along the axial direction of the catheter body 110. The inflated diameters of the first balloon 121 and the third balloon 123 are both larger than the inflated diameter of the second balloon 122. In this embodiment, the second balloon 122 is a single-layer balloon with a plurality of micropores 124 for releasing medication. The pore size of the micropores 124 is 5.0 μm to 500 μm, preferably 10 μm to 250 μm, and more preferably 10 μm to 50 μm. The number of micropores 124 is 5.0 to 100, preferably 5.0 to 50, and more preferably 5.0 to 25. Furthermore, the micropores 124 are uniformly arranged around the longitudinal axis of the second balloon 122, and are arranged in several layers along the longitudinal axis.

[0055] In this embodiment, the catheter body 110 includes a fluid inlet channel 111, a fluid return channel 112, and a filling channel 113, which are isolated from each other. The fluid inlet channel 111 is used to deliver medication to the second balloon 122 and the third balloon 123, causing the second balloon 122 and the third balloon 123 to inflate. After inflation, medication is also delivered to the second balloon 122 through the fluid inlet channel 111. The pressure of the medication causes it to overflow from the micropores 124 of the second balloon 122 into the blood vessel. Specifically, the fluid inlet channel 111 has at least two inlets (not shown), which are respectively connected to the second balloon 122 and the third balloon 123, thereby allowing the fluid inlet channel 111 to deliver medication to the second balloon 122 and the third balloon 123 through the inlets. The filling channel 113 is used to deliver a filling medium to the first balloon 121, causing the first balloon 121 to inflate. Specifically, the inflation channel 113 has at least one inflation port (not shown) communicating with the first balloon 121 to deliver an inflation medium to the first balloon 121. The invention does not limit the inflation medium; it is primarily a liquid, including but not limited to physiological saline, and may also include contrast agents. The distal ends of both the inlet channel 111 and the inflation channel 113 are closed, and the distal end of the return channel 112 has at least one aspiration port 114, preferably located between the first balloon 121 and the second balloon 122.

[0056] In another preferred embodiment, the third balloon 123 may not be provided; instead, it may be implemented by providing a protrusion at the distal end of the second balloon 122. In this embodiment, the balloon 120 includes a first balloon 121 (i.e., a proximal balloon) and a second balloon 122 (i.e., a distal balloon). The second balloon 122 includes a proximal portion and a distal portion. The diameter (including the maximum diameter) of the inflated distal portion is larger than the diameter (including the maximum diameter) of the inflated proximal portion. The micropore is located on the surface of the proximal portion.

[0057] In another preferred embodiment, the second balloon 122 may be omitted; instead, an opening is directly made on the surface of the catheter body 110 for releasing the medication. In this embodiment, the balloon 120 includes a first balloon 121 (i.e., a proximal balloon) and a third balloon 123 (i.e., a distal balloon), and micropores are formed in the segment of the inlet channel 111 located between the first balloon 121 and the third balloon 123.

[0058] In another preferred embodiment, the shapes of the first balloon 121 and / or the third balloon 123 are specially designed to address the problem of vascular calcification lesions. For example... Figure 6 As shown, the first balloon 121 expands into a disc shape. In its expanded state, the length of the first balloon 121 along the catheter axial direction is less than the height of its radial protrusion; preferably, the height of the protrusion is twice or more than its length. In a more preferred embodiment, the first balloon 121 is a non-compliant balloon with a maximum expansion diameter equal to or slightly larger than the vessel diameter, allowing for free deformation within the blocked vessel. This achieves good occlusion in cases of vascular calcification while minimizing damage to the vessel. Similarly, not shown, the third balloon 123 also expands into a disc shape. In its expanded state, the length of the third balloon 123 along the catheter axial direction is less than the height of its radial protrusion; preferably, the height of the protrusion is twice or more than its length. In a more preferred embodiment, the third balloon 123 is also a non-compliant balloon, achieving good occlusion in cases of vascular calcification while minimizing damage to the vessel. It should be understood that when micropores are formed in the inlet channel or the distal balloon, the axial length of the proximal balloon after inflation is preferably less than its radial height. It should also be understood that when micropores are formed on the surface of the inlet channel, the axial length of the distal balloon after inflation is preferably less than its radial height.

[0059] The following description primarily uses three balloons as an example, but it should not be construed as limiting the invention. Those skilled in the art should be able to apply the following description to the case of two balloons.

[0060] Figure 3 This is a schematic diagram of the balloon catheter provided in a preferred embodiment of the present invention during use. Figure 3 As shown, taking an interventional vascular system as an example, after the balloon catheter 100 is inserted into the interventional vascular system S, the three balloons inflate. The first balloon 121 and the third balloon 123 bulge proximally and distally to the second balloon 122, briefly blocking the vascular system S and preventing blood flow. Subsequently, medication is delivered to the second balloon 122 via the inlet channel 111. Under the pressure of the medication, the medication overflows through the micropores 124 on the second balloon 122 into the vascular system S. Due to the concentration gradient of the medication, the overflowing medication diffuses and transfers into the vascular tissue, where it is absorbed. Figure 3 The middle arrow indicates the direction of drug flow. Simultaneously with drug infusion, the drug solution around the second balloon 122 is aspirated through at least one aspiration port 114 at its distal end via the return channel 112. A portion of the overflowing drug solution is then drawn back into the return channel 112 (the aspirated drug solution is not used). Meanwhile, new drug solution is continuously delivered to the second balloon 122 through the inlet channel 111 and overflows through the micropore 124. This ensures that the drug solution within the blocked blood vessel S maintains a consistently high concentration (i.e., the drug concentration within the blood vessel is higher than the concentration within the vascular tissue), facilitating drug diffusion into the vascular tissue under the influence of the concentration gradient, thereby improving drug transfer efficiency and absorption rate. Furthermore, the flow generated by the aspiration port 114 reduces the probability of thrombus formation, enhancing the safety of the device.

[0061] This invention does not limit the type of drug delivered, but may include, for example, drugs that inhibit cell proliferation, anti-inflammatory drugs, antibacterial drugs, antitumor drugs, antimitotic drugs, anti-osteoporosis drugs, and anti-angiogenic drugs. Furthermore, it may be a combination of multiple drugs. Illustratively, drugs may include, for example, mTOR inhibitors, paclitaxel and its derivatives, antiplatelet drugs, cilostazol, ticlopidine, tripterygium wilfordii, dexamethasone, methotrexate, fluorouracil, mercaptopurine, hydroxyurea, cytarabine, carboplatin, cisplatin, oxaliplatin, bicycloplatin, daunorubicin, doxorubicin, and arsenic trioxide, in one or more combinations. The mTOR inhibitor may be rapamycin (sirolimus), everolimus, desifolimus, tesimolimus, and zotacolimus, in one or more combinations.

[0062] In this embodiment, the catheter body 110 can be manufactured in parts. In some embodiments, the catheter body 110 can be assembled from an outer tube 110a and an inner tube 110b. See also... Figure 1 and Figure 2 The catheter body 110 includes an outer tube 110a and an inner tube 110b. For example... Figure 4As shown, the outer tube 110a is a three-lumen tube, specifically including an axially extending first inner lumen 115, a second inner lumen 116, and a third inner lumen 117. The distal end of the first inner lumen 115 is open and directly configured as a return fluid channel 112. The distal end of the third inner lumen 117 is closed and configured as a filling channel 113. Furthermore, the second inner lumen 116 is used to accommodate the inner tube 110b, and the distal end of the inner tube 110b extends out of the second inner lumen 116, thereby constructing an inlet fluid channel 111 by the inner tube 110b. Additionally, the first balloon 121 is fitted onto the outer tube 110a, while the second balloon 122 and the third balloon 123 are fitted onto the distal portions of the inner tube 110b extending from the outer tube 110a. In an alternative embodiment, the catheter body 110 can also be integrally manufactured, for example, by machining the outer tube 110a and the inner tube 110b.

[0063] Furthermore, such as Figure 5 As shown, the catheter body 110 also includes an aspiration catheter 110c for providing a return channel 112. The aspiration catheter 110c is inserted into the first lumen 115, and preferably, the distal end of the aspiration catheter 110c extends out of the first lumen 115 into the blood vessel. In this case, medication can be aspirated through at least one aspiration port 114 at its distal end via the aspiration catheter 110c. This method results in high aspiration efficiency and good aspiration effect. In this embodiment, a syringe or pump can be placed at the proximal end of the aspiration catheter 110c, allowing for manual or mechanical aspiration of the medication. It should also be understood that the distal end of the aspiration catheter 110c extending out of the first lumen 115 into the blood vessel is not necessary; in other cases, the distal end of the aspiration catheter 110c can also be hidden within the first lumen 115.

[0064] The outer tube 110a can also be a dual-lumen tube, including an axially extending first inner lumen 115 and a second inner lumen 116. The distal opening of the first inner lumen 115 is directly configured as a return fluid channel 112, while the second inner lumen 116 is used to accommodate the inner tube 110b, and the distal end of the inner tube 110b extends out of the second inner lumen 116, thereby providing a direct inlet channel 111 from the inner tube 110b. In this case, the first balloon 121 is fitted onto the outer tube 110a, while the second balloon 122 and the third balloon 123 are fitted onto the distal portion of the inner tube 110b extending out of the outer tube 110a. The inlet channel 111 has at least three inlets that communicate with the first balloon 121, the second balloon 122, and the third balloon 123, respectively, thereby delivering medication to the three balloons from the inner tube 110b, causing the three balloons to inflate. Similarly, when the outer tube 110a is a double-lumen tube, the return channel 112 can also be provided by the suction conduit 110c.

[0065] Furthermore, the catheter body 110 also has a guidewire lumen for inserting a guidewire. For example, the inner tube 110b provides the guidewire lumen. The proximal and distal ends of the second balloon 122 are also provided with contrast markers to determine the location where medication needs to be infused. The contrast markers are made of a metallic contrasting material. In some embodiments, contrast markers are provided near the proximal and distal ends of the second balloon 122, respectively; in some embodiments, contrast markers are provided near the distal end of the first balloon 121 and near the proximal end of the third balloon 123. The contrast markers can be contrast points or contrast rings.

[0066] In this embodiment, the number of suction ports 114 is one. In other embodiments, the number of suction ports 114 may be multiple, including two or more.

[0067] Next, this embodiment also provides experimental results comparing the drug transfer effect of existing drug-coated balloons and the balloon catheter of the present invention; wherein, a micro-injection needle is used to drill holes in a direction perpendicular to the longitudinal axis of the second balloon 122 to form micropores 124, the pore size of which is 245 μm. Figure 7 As shown, after drilling, the pore size of micropore 124 can be confirmed using a microscope. Figure 7 This is a micrograph of a 245 μm micropore (124). Furthermore, in the experiment, animal blood vessels were used in vitro, with a sample size of 3 replicates.

[0068] Specifically, a conventional drug-coated balloon was prepared, wherein the drug was a mixture of paclitaxel and iopromide in a 1:1 mass ratio, and was coated onto the balloon surface using ultrasonic spraying. After inflation, the balloon had a diameter of 3.0 mm and a length of 18 mm, with a total drug content of 508 micrograms. In the balloon catheter of this invention, equal volumes of paclitaxel and the surfactant Tween80 were added to water and ultrasonically agitated using a probe for 180 minutes to ensure uniform dispersion, serving as the perfusion solution. During the experiment, the drug-coated balloon inflated for 60 seconds after entering the blood vessel, while the balloon catheter of this invention infused 1 ml of the drug solution within 60 seconds of entering the blood vessel, with a drug content of 508 micrograms. After inflation or perfusion, the experimental blood vessel segment was cut off, and the drug tissue concentration of both was tested. The experimental results are as follows: Figure 8 As shown. Experimental results indicate that, after using the balloon catheter of the present invention, the immediate tissue drug concentration is 2.5 times that of a drug-coated balloon, demonstrating that the balloon catheter of the present invention has a significant drug transfer effect.

[0069] In summary, the technical solution provided by the embodiments of the present invention utilizes balloon infusion to deliver drugs to tissues, solving the problem of significant drug loss during delivery using traditional drug-coated balloons. This results in good drug delivery and high drug transfer efficiency. Furthermore, by occluding blood vessels with proximal and distal balloons, the loss of drug solution flowing to both ends during infusion is further reduced, further improving drug transfer efficiency. In addition, the aspiration of drug solution through an aspiration catheter not only further improves the efficiency of drug transfer to tissues but also reduces the risk of thrombus formation within the occluded blood vessel, ensuring good safety. Moreover, the disc-shaped proximal and / or distal balloons effectively address the problem of vascular calcification, leading to better therapeutic effects.

[0070] It should be understood that the above embodiments specifically disclose the features of preferred embodiments of the present invention, enabling those skilled in the art to better understand the present invention. Those skilled in the art should understand that, based on the disclosure of this application, appropriate modifications can be easily made to the present invention to achieve the same purpose and / or the same advantages as the embodiments disclosed herein. Those skilled in the art should also recognize that such similar structures do not depart from the scope of the present invention, and that they can be changed, substituted, and modified in various ways without departing from the scope of the present invention.

Claims

1. A balloon catheter, characterized in that, The catheter includes a catheter body and a balloon, wherein the balloon comprises a first balloon, a second balloon and a third balloon, the first balloon, the second balloon and the third balloon being sequentially and spaced apart from the proximal end to the distal end of the catheter body along the axial direction of the catheter body; the first balloon, the second balloon and the third balloon are all made of non-compliant or semi-compliant materials; The diameters of the first balloon and the third balloon after inflation are both larger than the diameter of the second balloon after inflation; the first balloon and the third balloon adhere to the blood vessel wall after inflation, while the second balloon does not adhere to the blood vessel wall after inflation, leaving a gap; The catheter body includes an outer tube and an inner tube; the outer tube includes an axially extending first inner lumen and a second inner lumen, the distal end of the first inner lumen being open; an aspiration catheter is inserted into the first inner lumen, the aspiration catheter providing a return fluid channel, and the distal end of the aspiration catheter extending out of the first inner lumen; the inner tube is inserted into the second inner lumen and extends beyond the distal end of the second inner lumen; a second balloon and a third balloon are fitted onto the distal portion of the inner tube extending out of the outer tube; the first balloon is fitted onto the outer tube; the inner tube is configured as an inlet fluid channel; The inlet channel is used to deliver liquid to the second balloon, and the surface of the second balloon has a plurality of micropores for releasing the liquid; the distal end of the return channel has at least one suction port, and at least one suction port is located at the proximal end of the second balloon, so as to draw back the liquid around the second balloon through at least one suction port, so that the liquid in the occlusion area can be maintained at a high concentration, which helps the liquid to continuously diffuse into the target tissue, and the suction effect of the return channel drives the liquid circulation in the occlusion area.

2. The balloon catheter according to claim 1, characterized in that, The catheter body further includes a filling channel, which is isolated from the inlet channel and the return channel respectively; the outer tube further includes an axially extending third inner cavity, which is configured as the filling channel; The inflation channel has at least one inflation port, which communicates with the first balloon to deliver an inflation medium to the first balloon through the inflation channel, thereby inflating the first balloon. The inlet channel has at least two inlets, which are respectively connected to the second balloon and the third balloon, so as to deliver liquid to the second balloon and the third balloon through the inlet channel, causing the second balloon and the third balloon to inflate.

3. The balloon catheter according to claim 1, characterized in that, The inlet channel has at least three inlets, which are respectively connected to the first balloon, the second balloon and the third balloon, so as to deliver liquid to the first balloon, the second balloon and the third balloon through the inlet channel, so as to inflate the first balloon, the second balloon and the third balloon.

4. The balloon catheter according to claim 1, characterized in that, The second balloon is a single-layer balloon or a double-layer balloon; when the second balloon is a double-layer balloon, a number of micropores are formed on the surface of the outer layer of the double-layer balloon, or a number of micropores are formed on the surface of both the outer and inner layers of the double-layer balloon.

5. The balloon catheter according to claim 1, characterized in that, The axial length of the first balloon after inflation is less than its radial height, and / or the axial length of the third balloon after inflation is less than its radial height.

6. A balloon catheter, characterized in that, The catheter includes a catheter body and a balloon, the balloon comprising a proximal balloon and a distal balloon, the proximal balloon and the distal balloon being sequentially spaced on the catheter body from proximal to distal along the axial direction of the catheter body; the proximal balloon, after inflation, adheres to the vessel wall; both the proximal balloon and the distal balloon are non-compliant balloons; The catheter body includes an outer tube and an inner tube; the outer tube includes an axially extending first inner lumen and a second inner lumen, with the distal end of the first inner lumen open; an aspiration catheter is inserted into the first inner lumen, the aspiration catheter providing a return fluid channel, and the distal end of the aspiration catheter extending out of the first inner lumen; the inner tube is inserted into the second inner lumen and extends beyond the distal end of the second inner lumen; a distal balloon is fitted over the distal portion of the inner tube extending out of the outer tube; a proximal balloon is fitted over the outer tube; the inner tube is configured as an inlet fluid channel; The inlet channel is used to deliver liquid; several micropores are formed on the surface of the distal balloon or the inlet channel for releasing the liquid; the distal end of the return channel has at least one aspiration port, through which liquid outside the balloon catheter is aspirated to maintain a high concentration of liquid in the occlusion area, helping the liquid to continuously diffuse into the target tissue, and the aspiration action of the return channel drives the circulation of liquid in the occlusion area; at least one aspiration port is located between the proximal balloon and the distal balloon; When the distal balloon has micropores on its surface, the distal balloon includes a proximal portion and a distal portion. The diameter of the distal portion after expansion is larger than the diameter of the proximal portion after expansion. The micropores are located on the surface of the proximal portion. After expansion, the proximal portion does not adhere to the blood vessel wall but leaves a gap, while the distal portion adheres to the blood vessel wall after expansion. When the inlet channel has micropores on its surface, the distal balloon adheres to the blood vessel wall after expansion.

7. The balloon catheter as described in claim 6, characterized in that, The axial length of the proximal balloon after inflation is less than its radial height.

8. The balloon catheter as described in claim 6, characterized in that, When a number of micropores are formed on the surface of the inlet channel, the axial length of the distal balloon after inflation is less than its radial height.

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