Balloon catheter and preparation method thereof

Abstract

The present invention relates to a balloon catheter and a preparation method thereof, wherein the balloon catheter comprises a catheter body and a balloon, wherein the balloon is sleeved on the catheter body, and the balloon comprises at least one first balloon, wherein the first balloon is provided with a plurality of first micropores, and a retaining wall is provided at the first micropores; when the balloon is expanded, the retaining wall is inclined toward the corresponding first micropores to at least partially cover the first micropores, and a liquid medicine channel is reserved between the retaining wall and the first micropores, and the extension direction of the liquid medicine channel is not perpendicular to the longitudinal axis of the balloon catheter. The present invention uses the retaining wall to buffer the liquid medicine, which not only reduces the injection speed of the liquid medicine, but also changes the injection direction of the liquid medicine, thereby reducing the stimulation of the liquid medicine on the blood vessels and reducing the occurrence of vascular spasm.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a balloon catheter and a preparation method thereof. Background Art

[0002] Since the 1970s, it has become increasingly common to treat various cardiovascular diseases through interventional medical devices. It has experienced three milestones of rapid development: percutaneous balloon angioplasty (PTCA), bare metal stents (BMS), and drug-eluting stents (DES). In particular, the emergence of drug-coated stents has achieved great success in treating vascular stenosis, showing the potential of DES in treating stenosis. At present, DES is the first choice for the treatment of obstructive coronary heart disease, but it has problems such as late stent thrombosis, long vascular healing time, and easy impact on vascular pulsation. In addition, the application of DES is limited in in-stent restenosis (ISR), small vessel lesions, and bifurcation lesions. In this case, drug-coated balloons (DCBs) came into being and showed good therapeutic effects.

[0003] The drug-eluting balloons currently on the market all have anti-proliferative drugs coated on the balloon surface. When in use, the balloon is pushed to the target lesion to expand the balloon to release the drug. This design of drug-eluting balloon faces the following challenges: (1) The drug is easily lost during the pushing process, resulting in insufficient drug dosage or even toxic side effects caused by the lost drug; (2) The drug coated on the surface of the drug balloon is easy to form large drug particles during expansion, which can easily cause distal vascular embolism and pose a high safety risk; (3) The drug dosage is uncontrollable, and one balloon can only be used in one part. In response to these problems, people have designed a perfusion drug balloon, which is to inject the drug solution from the inner cavity of the balloon and flow out through the micropores on the balloon surface or other parts of the micropores, and the drug solution is absorbed by the tissue. The advantages of this design of drug-eluting balloon are that there is no loss of drug during the pushing process, no large particles are generated, and the drug dosage is controllable.

[0004] Although the drug-perfused balloon has solved some of the problems of drug-coated balloons, the problems in use caused by its own design are still worthy of attention. In some existing drug-perfused balloons, the drug solution will be directly pressed and sprayed out through the micropores of the outer balloon without any obstruction. The high-speed sprayed liquid flow will stimulate the blood vessel wall and cause vascular spasm, which poses a great safety risk. In addition, the outflowing liquid flow will diffuse outward without direction, resulting in a large amount of drug loss. There are also some other drug-perfused balloons, whose two ends bulge to block blood flow. Although this solves the problem of drug solution loss, the closed two ends are very likely to retain blood and cause thrombosis, which is very risky. In addition, if the pressure of the drug solution is reduced, the drug cannot be effectively absorbed, reducing the therapeutic effect. Summary of the invention

[0005] The object of the present invention is to provide a balloon catheter and a preparation method thereof, so as to solve the problems of the existing drug-infused balloon that is easy to cause vascular spasm and thrombosis, large loss of drug solution and low drug transfer efficiency.

[0006] To achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided a balloon catheter, comprising a catheter body and a balloon, wherein the balloon is sleeved on the catheter body, and the balloon comprises at least one first balloon, wherein the first balloon is provided with a plurality of first micropores, and wherein a barrier wall is provided at the first micropores; when the balloon is expanded, the barrier wall is inclined toward the corresponding first micropores to at least partially cover the first micropores, and a drug solution channel is reserved between the barrier wall and the corresponding first micropores, and an extension direction of the drug solution channel is not perpendicular to the longitudinal axis of the balloon catheter.

[0007] Optionally, the distribution density of the first micropores at the proximal end of the balloon is higher than the distribution density of the first micropores at the distal end of the balloon; and / or, the pore size of the first micropores at the proximal end of the balloon is larger than the pore size of the first micropores at the distal end of the balloon.

[0008] Optionally, when the balloon is expanded, the retaining wall close to the proximal end of the balloon is inclined toward the proximal end of the balloon, and the remaining retaining wall is inclined toward the middle of the balloon.

[0009] Optionally, when the balloon is expanded, all the retaining walls are inclined toward the middle of the balloon.

[0010] Optionally, the blocking wall is configured to be variable in position relative to the first microhole to adjust the extension direction of the drug solution channel.

[0011] Optionally, the retaining wall is formed by extending outward from the corresponding hole wall of the first microhole.

[0012] Optionally, the balloon further comprises a second balloon, the second balloon is nested in the first balloon; a plurality of second micro-holes are formed on the second balloon; the catheter body has a filling cavity;

[0013] The filling chamber is used to deliver liquid medicine to the second balloon to expand the balloon. The filling chamber is also used to deliver liquid medicine to the second balloon so that the liquid medicine flows into the first balloon through a plurality of the second micropores under pressure and then flows out of the first balloon through a plurality of the first micropores.

[0014] Optionally, a plurality of the second micropores and a plurality of the first micropores are staggered in a transverse direction of the balloon.

[0015] Optionally, the pore size of the second micropores ranges from 5.0 μm to 500 μm, and the pore size of the first micropores ranges from 5.0 μm to 800 μm.

[0016] Optionally, the balloon further comprises a second balloon, wherein the second balloon is nested in the first balloon; the catheter body comprises a filling cavity and a drug delivery cavity which are isolated from each other;

[0017] The filling chamber is used to deliver a filling medium to the second balloon to expand the balloon; the drug delivery chamber is used to deliver a drug solution to the first balloon to allow the drug solution to flow out of the first balloon through the first micropores under pressure.

[0018] To achieve the above object, according to one aspect of the present invention, a method for preparing a balloon catheter is provided, comprising:

[0019] Providing a catheter body and a balloon, and sleeve the balloon on the catheter body;

[0020] A plurality of microholes are formed on the balloon, and a retaining wall is arranged at each microhole;

[0021] The retaining wall is configured to tilt toward the corresponding micropore when the balloon is expanded to at least partially cover the micropore, and a drug liquid channel is reserved between the retaining wall and the corresponding micropore, and the extension direction of the drug liquid channel is not perpendicular to the longitudinal axis of the balloon catheter.

[0022] Optionally, in the preparation method, when micropores are opened on the balloon, the distribution density of the micropores at the proximal end of the balloon is higher than the distribution density of the micropores at the distal end of the balloon, and / or the pore size of the micropores at the proximal end of the balloon is larger than the pore size of the micropores at the distal end of the balloon.

[0023] Optionally, in the preparation method, after the balloon is expanded, the retaining wall close to the proximal end of the balloon is inclined toward the proximal end of the balloon, and the remaining retaining wall is inclined toward the middle of the balloon.

[0024] Optionally, in the preparation method, when the balloon is expanded, all the retaining walls are inclined toward the middle of the balloon.

[0025] Optionally, in the preparation method, the diameter of the balloon after expansion remains uniform.

[0026] Compared with the prior art, the balloon catheter and the preparation method thereof provided by the present invention have at least one of the following advantages:

[0027] The balloon catheter is provided with a baffle wall at the first microhole of the first balloon, which can buffer the drug solution through the baffle wall, not only reducing the injection speed of the drug solution, but also changing the injection direction of the drug solution, which can effectively block the stimulation of the blood vessel wall by the liquid flow under high pressure, complete the perfusion of the drug solution in a gentle manner, and reduce the occurrence of vascular spasm.

[0028] The retaining wall is preferably inclined toward the middle of the balloon so that the liquid medicine is sprayed toward the middle of the balloon. This standardizes the diffusion direction of the liquid medicine, effectively reduces the loss of the liquid medicine flowing to both ends, and improves the drug transfer rate. Moreover, the diameter of the first balloon after expansion is uniform, and there is no need to block the front and rear ends of the lesion during the intervention process, which avoids the formation of thrombus by residual blood and improves the safety of the device. In addition, the position of the retaining wall relative to the first micropore is variable, so that the spray direction of the liquid medicine can be adjusted at any time, which is more flexible and convenient to use.

[0029] The distribution density of the first micropores at the proximal end of the balloon is higher than the distribution density of the first micropores at the distal end of the balloon, or the aperture of the first micropores at the proximal end of the balloon is larger than the aperture of the first micropores at the distal end of the balloon, or, when the balloon is expanded, the retaining wall close to the proximal end of the balloon is inclined toward the proximal end of the balloon, and the remaining retaining wall is inclined toward the middle of the balloon. These methods can make the drug diffuse evenly to the blood vessel wall, alleviate the influence of blood pressure and blood flow scouring on the proximal end of the balloon, reduce the loss of drug solution, and further improve the drug transfer rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0031] Figure 1 is an axial cross-sectional view of a balloon catheter and its balloon when it is not expanded provided by a preferred embodiment 1 of the present invention;

[0032] Figure 2 yes Figure 1 A partial enlarged view of the balloon catheter is shown;

[0033] Figure 3 is an axial cross-sectional view of a balloon catheter and its balloon expansion provided in a preferred embodiment of the present invention;

[0034] Figure 4 yes Figure 3 A partial enlarged view of the balloon catheter is shown;

[0035] Figure 5 is an axial cross-sectional view of a balloon catheter and its balloon when it is not expanded provided by a second preferred embodiment of the present invention;

[0036] Figure 6 yes Figure 5 A partial enlarged view of the balloon catheter is shown;

[0037] Figure 7 is an axial cross-sectional view of a balloon catheter and its balloon expansion provided in a second preferred embodiment of the present invention;

[0038] Figure 8 yes Figure 7A partial enlarged view of the balloon catheter is shown;

[0039] Fig. 9 It is an axial cross-sectional view of a balloon catheter and its balloon expansion provided by another preferred embodiment of the present invention.

[0040] In the figure:

[0041] Balloon catheter 100, 200; catheter body 110, 210; balloon 120, 220; inner balloon 121, 221; outer balloon 122, 222; first micropore 124, 223; second micropore 123; barrier wall 125, 224; drug solution channel 126.

[0042] The same or similar reference numerals in the drawings represent the same or similar components. DETAILED DESCRIPTION

[0043] The following is an explanation of the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the present embodiment only illustrate the basic concept of the present invention in a schematic manner, and only the components related to the present invention are shown in the figure instead of being drawn according to the number, shape and size of the components in the actual implementation. The type, quantity and proportion of each component in the actual implementation can be a random change, and the component layout type may also be more complicated.

[0044] In addition, each embodiment of the following description has one or more technical features, but this does not mean that the user of the present invention must implement all the technical features in any embodiment at the same time, or can only implement part or all of the technical features in different embodiments separately. In other words, under the premise that implementation is possible, those skilled in the art can selectively implement part or all of the technical features in any embodiment according to the disclosure of the present invention and according to the design specifications or implementation requirements, or selectively implement a combination of part or all of the technical features in multiple embodiments, thereby increasing the flexibility of the implementation of the present invention.

[0045] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings. It should be noted that the accompanying drawings are all in very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. As used in this specification, the singular forms "one", "a" and "the" include plural objects, unless the content clearly indicates otherwise. As used in this specification, the meaning of "multiple" generally includes two or more, unless the content clearly indicates otherwise. As used in this specification, the term "or" is generally used to include the meaning of "and / or", unless the content clearly indicates otherwise. The term "axial" generally refers to the direction parallel to the longitudinal axis of the balloon catheter; "lateral" generally refers to the direction perpendicular to the axial direction; "proximal" generally refers to the direction close to the balloon catheter operator; "distal" refers to the direction away from the balloon catheter operator. It should also be understood that the present invention repeats reference numbers and / or letters in various embodiments. This repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or configurations discussed. It will also be understood that when an element is referred to as being “connected to” another element, it can be directly connected to the other element, or one or more intervening elements may be present.

[0046] The core idea of ​​the present invention is to provide a balloon catheter, including a catheter body and a balloon, the balloon is sleeved on the catheter body, the balloon includes at least one first balloon, the first balloon is provided with a plurality of first micropores, and a retaining wall is provided at the first micropore. In actual operation, after the balloon is expanded, the retaining wall is inclined toward the corresponding first micropore to at least partially cover the first micropore, and a liquid medicine channel is reserved between the retaining wall and the corresponding first micropore, and the extension direction of the liquid medicine channel is not perpendicular to the longitudinal axis of the balloon catheter; in this way, in the working state, under the pressure of the drug, the liquid medicine in the first balloon flows out from the first micropore and then sprays into the blood vessel through the liquid medicine channel, and the spraying direction of the liquid medicine is not perpendicular to the longitudinal axis of the balloon catheter. Therefore, the balloon catheter of the present invention can buffer the liquid medicine through the retaining wall, reduce the spraying speed of the liquid medicine, and change the spraying direction of the liquid medicine so that the spraying direction of the liquid medicine is no longer perpendicular to the blood vessel wall, thereby completing the perfusion of the liquid medicine in a gentle manner, reducing the stimulation to the blood vessel wall, and reducing the occurrence of vascular spasm.

[0047] It should be known that the balloon of the present invention can be a single-layer balloon or a double-layer balloon. When the balloon is a single-layer balloon, the catheter body has only one filling cavity, which is used to transport liquid medicine to the inside of the balloon to expand the balloon. After expansion, under the action of pressure, the liquid medicine further flows out from the micropores on the balloon and enters the blood vessel. When the balloon is a double-layer balloon, the balloon includes an inner balloon and an outer balloon, and the inner balloon is sleeved in the outer balloon. In an optional scheme, a plurality of first micropores are provided on the outer balloon, and a plurality of second micropores are provided on the inner balloon. At this time, the catheter body has only one filling cavity, and the filling cavity is used to transport liquid medicine to the inner balloon to expand the inner and outer balloons. After expansion, under the action of pressure, the liquid medicine flows into the outer balloon through a plurality of the second micropores, and then flows out of the outer balloon through a plurality of the first micropores and enters the blood vessel. In another optional scheme, only the outer balloon is provided with a plurality of micropores (i.e., the first micropores), while the inner balloon is not provided with any micropores. In this case, the catheter body has a mutually isolated filling cavity and a drug delivery cavity, and a filling medium (such as a contrast solution) is delivered to the inner balloon through the filling cavity to expand the inner and outer balloons. After expansion, a drug solution is delivered to the outer balloon through the drug delivery cavity, and under the pressure of the drug solution, the drug solution flows out of the outer balloon through a plurality of micropores and enters the blood vessel. Here, it should be known that "micropores" refer to holes with a size of micrometers. The present invention does not limit the shape of the micropores. For the convenience of processing, circular micropores are preferred.

[0048] In addition, the inner balloon and the outer balloon of the present invention are both made of non-compliant or semi-compliant materials, and will no longer expand with increasing pressure after expanding to a specified size as the pressure increases. The use of non-compliant or semi-compliant materials avoids the obstruction of drug absorption after the balloon and the blood vessel wall are attached, thereby improving the drug absorption rate. In addition, when the balloon is a single-layer balloon, it is preferred that the diameter of the balloon after expansion is uniform; similarly, when the balloon is a double-layer balloon, it is preferred that the diameter of the outer balloon after expansion is uniform; with this arrangement, there is no need to block the front and rear ends of the lesion during the intervention process, thereby avoiding the formation of thrombi by residual blood and improving the safety of the device.

[0049] Next, the balloon catheter and the preparation method thereof of the present invention will be further described in conjunction with the accompanying drawings and preferred embodiments to further highlight the characteristics and features of the above embodiments.

[0050] Embodiment 1

[0051] Figure 1 is an axial cross-sectional view of a balloon catheter and its balloon when it is not expanded provided in a preferred embodiment 1 of the present invention, Figure 2 yes Figure 1 The enlarged view of the balloon catheter is shown. Figure 3 is an axial cross-sectional view of a balloon catheter and its balloon expansion provided in a preferred embodiment of the present invention, Figure 4 yes Figure 3 A partial enlarged view of the balloon catheter is shown.

[0052] like Figure 1 to Figure 4 As shown, this embodiment provides a balloon catheter 100, which includes a catheter body 110 and a balloon 120, wherein the balloon 120 includes an inner balloon 121 (i.e., a second balloon) and an outer balloon 122 (i.e., a first balloon), wherein the inner balloon 121 and the outer balloon 122 are sequentially sleeved on the catheter body 110 from the inside to the outside, and after expansion, there is a gap between the outer balloon 122 and the inner balloon 121, that is, the expansion diameter of the outer balloon 122 is greater than the expansion diameter of the inner balloon 121, so as to avoid the inner balloon 121 and the outer balloon 122 from fitting together during expansion, and to prevent the first micropore on the outer balloon 122 from being occluded by the inner balloon 121, so as to ensure the smooth overflow of the drug. Optionally, under nominal pressure, the expansion diameters of the outer balloon 122 and the inner balloon 121 differ by 0.05 mm to 5.0 mm, and more preferably, the expansion diameters differ by 0.1 mm to 1.0 mm.

[0053] In addition, the outer balloon 122 is provided with a plurality of first micropores 124, and the diameter of the first micropores 124 is preferably 5.0 μm to 800 μm, more preferably the diameter of the first micropores 124 is 10.0 μm to 200 μm, and further preferably, the diameter of the first micropores 124 is 10.0 μm to 100 μm. The diameter of the first micropores 124 should not be too small, as it is easy to block large particles of medicine, and the diameter of the first micropores 124 can be larger than the second micropores 123, which is conducive to reducing the speed of the drug injection and reducing the stimulation to the blood vessels. The present invention does not limit the number of the first micropores 124, nor does it limit the distribution of the first micropores 124, which can be uniformly distributed or unevenly distributed. In this embodiment, the first micropores 124 are evenly arranged around the longitudinal axis of the outer balloon 122, and several layers are arranged along the longitudinal axis.

[0054] In addition, a plurality of second micropores 123 are provided on the inner balloon 121, and the diameter of the second micropores 123 is preferably 5.0 μm to 500 μm, more preferably the diameter of the second micropores 123 is 5.0 μm to 200 μm, and further preferably, the diameter of the second micropores 123 is 5.0 μm to 50 μm. Here, the diameter of the second micropores 123 should not be too large or too small. Too small may easily block large particles of medicine, and too large may affect the effective expansion of the inner balloon 121. The present invention does not limit the number of the second micropores 123, nor does it limit the distribution of the second micropores 123, which may be uniformly distributed or unevenly distributed. In this embodiment, the second micropores 123 are evenly arranged around the longitudinal axis of the inner balloon 121, and several layers are provided along the longitudinal axis.

[0055] The catheter body 110 is provided with a filling cavity (not shown) so that the liquid medicine is delivered to the inner balloon 121 through the filling cavity. Specifically, after the liquid medicine enters the inner balloon 121 through the catheter body 110, the inner balloon 121 and the outer balloon 122 are expanded. After the expansion, the liquid medicine is continuously infused into the inner balloon 121. Under the pressure of the liquid medicine, the liquid medicine flows into the outer balloon 122 through the second micropores 123 on the inner balloon 121, and then overflows into the blood vessel from the first micropores 124 on the outer balloon 122. Through the buffering effect of the outer balloon 122, the liquid medicine is prevented from being directly sprayed into the blood vessel at a high speed, thereby reducing the stimulation to the blood vessel and the occurrence of vascular spasm.

[0056] Furthermore, the inventors considered that simply using the outer balloon 122 to buffer the liquid medicine would not be very effective, because not only is the injection speed of the liquid medicine at the first micropore 124 very high, but the direction in which the liquid medicine is ejected from the first micropore 124 is also perpendicular to the direction of the blood vessel wall, so the stimulation to the blood vessel wall is still very large. For this reason, the balloon catheter 100 of this embodiment is also provided with a retaining wall 125 at the first micropore 124. Figure 3 As shown in FIG. 4 , when the balloon 120 is expanded (i.e., the balloon 120 is closely attached to the blood vessel wall), the retaining wall 125 is inclined toward the corresponding first micropore 124 to at least partially cover the first micropore 124, and the inclination angle α of the retaining wall 125 (i.e., the angle between the retaining wall 125 and the longitudinal axis of the balloon) is greater than 0° and less than 90°. At this time, a liquid medicine channel 126 is reserved between the retaining wall 125 and the corresponding first micropore 124 (see FIG. 4 ). Figure 4 ), and the extension direction of the drug channel 126 is not perpendicular to the longitudinal axis of the balloon catheter, so that under the pressure of the drug, the drug flows out through the second micropore 123 on the inner balloon 121 to between the inner balloon 121 and the outer balloon 22, and then overflows into the blood vessel from the first micropore 124 on the outer balloon 122 through the drug channel 126. In this process, the drug will pass through the buffering effect of the outer balloon 122 and the baffle 125, so that the speed of the drug injection at the first micropore 124 becomes smaller, and the direction of the drug outflow from the first micropore 124 is no longer perpendicular to the blood vessel wall. This arrangement can effectively block the stimulation of the blood vessel wall by the high-pressure liquid flow, complete the perfusion of the drug in a gentle way, and reduce the occurrence of vascular spasm. It should be known that Figure 3 The arrows shown in the figure represent the flow direction of the liquid medicine.

[0057] In more detail, when the medicine is perfused into the inner balloon 121, the inner balloon 121 gradually expands until the outer balloon 122 and the blood vessel wall are tightly fitted, and then the medicine is continued to be perfused into the inner balloon 121. Under the action of pressure, the medicine flows out through the second micropore 123 on the inner balloon 121 to between the inner balloon 121 and the outer balloon 22, and then overflows into the blood vessel from the first micropore 124 on the outer balloon 122 through the medicine channel 126. In this process, the outflow direction of the medicine is limited by the medicine channel 126, and the extension direction of the medicine channel 126 can be fixed or change with the change of pressure. For example, as the drug pressure increases, the inclination angle α also increases. Conversely, as the drug pressure decreases, the inclination angle α also decreases. Correspondingly, the extension direction of the medicine channel 126 changes with the change of the inclination angle α. When the extension direction of the liquid medicine channel 126 remains unchanged, in this embodiment, the retaining wall 125 can be configured to remain unchanged relative to the first micropore 124, so that it is fixed on the outer balloon 122. When the extension direction of the liquid medicine channel 126 is variable, in this embodiment, the retaining wall 125 is configured to be variable relative to the first micropore 124, so that it can be movably arranged on the outer balloon 122. At this time, the inclination angle of the retaining wall 125 can be adjusted in real time by the drug pressure, so as to adjust the injection speed and injection direction of the liquid medicine at the first micropore 124 at any time, which is more flexible and more convenient to use.

[0058] In more detail, when the balloon 120 is not expanded, the barrier wall 125 is in a closed state. At this time, the barrier wall 125 can be opened inwardly or outwardly parallel to the longitudinal axis of the balloon 120, that is, Figure 1 and Figure 2 As shown; when the balloon 120 is in the process of expansion or after expansion, as shown Figure 3 and Figure 4 As shown, the retaining wall 125 is pushed by the liquid medicine and further opens outwards. At this time, the retaining wall 125 extends toward the outside of the balloon 120 and forms the aforementioned inclination angle α, so that when the liquid medicine enters the first micropore 124, the retaining wall 125 at the first micropore 124 can further buffer the liquid medicine and change the injection direction of the liquid medicine. It should be understood that, here, "the retaining wall 125 opens inwards" means that the retaining wall 125 deviates from the longitudinal axis of the balloon and extends in a direction close to the longitudinal axis of the balloon; "the retaining wall 125 opens outwards" means that the retaining wall 125 deviates from the longitudinal axis of the balloon and extends in a direction away from the longitudinal axis of the balloon.

[0059] In this embodiment, the retaining wall 125 can completely cover the corresponding first micropore 124, that is, the first micropore 124 cannot be seen from the direction perpendicular to the axis of the balloon 120. In an alternative embodiment, the retaining wall 125 can also expose a portion of the corresponding first micropore 124, that is, only a portion of the first micropore 124 can be seen from the direction perpendicular to the axis of the balloon 120. Further, the retaining wall 125 is integrally formed with the outer balloon 122, for example, the outer balloon 122 can be directly pierced by a needle, on the one hand, the first micropore 124 is formed by acupuncture, and on the other hand, a portion of the outer balloon 122 connected to the first micropore 124 is formed into the retaining wall 125, that is, a portion of the outer balloon material on the hole wall of the first micropore 124 is retained to form the retaining wall 125 extending outward, so that the manufacturing is simple and the processing cost is low. In other embodiments, the retaining wall 125 and the outer balloon 122 may be formed separately. For example, the first microhole 124 is firstly formed on the outer balloon 122 , and then the thin-sheet retaining wall 125 is bonded to the first microhole 124 . In this case, the material of the retaining wall 125 is preferably the same as that of the outer balloon 122 .

[0060] In addition, when the balloon 120 is expanded, all the retaining walls 125 are preferably inclined toward the middle of the balloon 120, that is, extending toward the transverse central axis of the balloon 120. In this way, the liquid medicine can be sprayed toward the middle of the balloon 120 (see Figure 3 ), thereby standardizing the diffusion direction of the drug solution, effectively reducing the loss of the drug solution flowing to the two ends of the balloon, and improving the drug transfer rate. Moreover, during the drug solution perfusion process, the inner balloon 121 always maintains an expanded state, and continuously perfuses the drug solution into the inner balloon 121, achieving continuous perfusion of the drug, which can improve the absorption rate of the drug and improve the treatment effect. In addition, the diameter of the outer balloon 122 after expansion is preferably uniform, that is, the diameter at both ends of the outer balloon 122 is the same as the diameter in the middle of the outer balloon. In this way, there is no need to block the front and rear ends of the lesion during the intervention process, avoiding the formation of thrombi by residual blood, and improving the safety of the device. The shape of the outer balloon 122 after expansion is cylindrical as a whole, and has a good wall adhesion effect. The present invention does not limit the shape of the inner balloon 121. The diameters at both ends of the inner balloon 121 may be the same as or different from the diameter in the middle of the inner balloon. Preferably, the diameter of the inner balloon 121 after expansion is uniform. Correspondingly, the shape of the inner balloon 121 after expansion is also cylindrical as a whole. It should be understood that the middle of the balloon (the middle is the transverse center axis of the balloon) should not be narrowly understood as an absolute middle position, and in some cases, it also includes a position deviating from the middle. In addition, it should be understood that when the first microhole 124 is exactly opened on the transverse center axis of the balloon, the retaining wall 125 can be arranged on one side of the transverse center axis, and preferably the retaining wall 125 is inclined toward the transverse center axis.

[0061] Furthermore, in order to better block the liquid medicine, the second micropores 123 on the inner balloon 121 and the first micropores 124 on the outer balloon 122 are arranged in a staggered manner in the transverse direction of the balloon (i.e., the axial positions are different), so that the liquid medicine can be blocked by the wall of the outer balloon 122 after flowing out from the second micropores 123, thereby achieving the purpose of buffering. Furthermore, in this embodiment, the first micropores 124 are evenly arranged around the longitudinal axis of the outer balloon 122, and several layers are arranged along the longitudinal axis. At this time, it is preferred that the retaining wall 125 is evenly arranged around the longitudinal axis of the outer balloon 122, and several layers are arranged along the longitudinal axis, and the retaining wall 125 is inclined toward the middle of the balloon, so that the liquid medicine sprayed out of each first micropore 124 is sprayed 360° toward the middle of the balloon, and the drug transfer efficiency is high.

[0062] Further in this embodiment, the catheter body 110 can be a single-lumen tube or a multi-lumen tube, and a filling cavity and a guidewire cavity are provided therein. The distal end of the filling cavity has at least one perfusion port, which is communicated with the interior of the inner balloon 121. The distal end of the catheter body 110 is provided with a developing mark for marking the position of the proximal and distal ends of the balloon. In addition, both the inner balloon 121 and the outer balloon 122 can be made of non-compliant materials or semi-compliant materials.

[0063] The present invention does not limit the types of drugs in the drug solution, and can be selected according to actual needs, such as anti-proliferative drugs, anti-inflammatory drugs, anti-inflammatory drugs, anti-proliferative drugs, antibacterial drugs, anti-tumor drugs, anti-mitotic drugs, cell-inhibiting drugs, cytotoxic drugs, anti-osteoporosis drugs, anti-angiogenic drugs, anti-restenosis drugs, microtubule-inhibiting drugs, anti-metastasis drugs or anti-thrombotic drugs, etc. Drugs include but are not limited to the following drugs: dexamethasone, prednisolone, corticosterone, budesonide, estrogen, sulfasalazine, aminosalicylic acid, acemetacin, aescin, aminopterin, antimycotics, arsenic trioxide, aristolochic acid, aspirin, scutellariae, ginkgo biloba, rapamycin and its derivatives (including zotarolimus, everolimus, biolimus, 7-O-desmethylrapamycin, temsirolimus, dafolimus, etc.), endostatin, angiostatin, blood The invention can be used in combination with the following: guanopeptidin, monoclonal antibodies capable of blocking smooth muscle cell proliferation, levofloxacin, paclitaxel, docetaxel, hydroxycamptothecin, vinblastine, vincristine, doxorubicin, 5-fluorouracil, cisplatin, thymidine kinase inhibitor antibiotics (especially actinomycin-D), hormones, antibody anticancer drugs, bisphosphonates, selective estrogen receptor modulators, strontium ranelate, cyclosporine A, cyclosporine C and brefeldin A; it can also be a combination of these drugs.

[0064] In combination with the preferred embodiment, the working principle of the balloon catheter 100 of this embodiment is further described. First, expand the balloon 120: the liquid medicine (containing the medicine) is delivered to the inner balloon 121 through the filling cavity of the catheter body 110, so that the inner balloon 121 gradually expands, and the outer balloon 12 also expands accordingly, until the outer balloon 122 and the blood vessel wall are closely attached to expand the narrow lesion. Then, spray the liquid medicine: after the balloon 120 is expanded, continue to deliver the liquid medicine to the inner balloon 120, so that the liquid medicine flows out to the outer balloon 122 through the second micropore 123 on the inner balloon 121 under pressure, and then further flows out into the blood vessel through the first micropore 124 on the outer balloon 122 and through the liquid medicine channel 126 under pressure. After the treatment is completed, the liquid medicine is withdrawn to shrink the balloon 120, and then the balloon catheter 100 is withdrawn from the body.

[0065] Embodiment 2

[0066] Figure 5 The axial cross-sectional view of the balloon catheter and the balloon when it is not expanded provided in the second preferred embodiment of the present invention, Figure 6 for Figure 5 A partial enlarged view of the balloon catheter. Figure 7 The axial cross-sectional view of the balloon catheter and the balloon expansion thereof provided in this embodiment is as follows: Figure 8 for Figure 7 A partial enlarged view of the balloon catheter.

[0067] like Figure 5 ~ and Figure 8 As shown, this embodiment provides a balloon catheter 200, which includes a catheter body 210 and a balloon 220, wherein the balloon 220 includes an inner balloon 221 and an outer balloon 222, wherein the inner balloon 221 and the outer balloon 222 are sequentially sleeved on the catheter body 210 from the inside to the outside, and after expansion, there is a gap between the outer balloon 222 and the inner balloon 221, that is, the expansion diameter of the outer balloon 222 is greater than the expansion diameter of the inner balloon 221, so as to avoid the inner balloon 221 and the outer balloon 222 from being attached during expansion, and to prevent the first micropore on the outer balloon 222 from being occluded by the inner balloon 221, so as to ensure the smooth overflow of the drug. Optionally, under nominal pressure, the expansion diameters of the outer balloon 222 and the inner balloon 221 differ by 0.05mm to 5.0mm, and more preferably, the expansion diameters differ by 0.1mm to 1.0mm.

[0068] Different from the first embodiment, the inner balloon 221 is not provided with micropores (i.e., isolated from the outer balloon 222), but only a plurality of first micropores 223 are provided on the outer balloon 222, and the diameter of the first micropore 223 is preferably 5.0 μm to 800 μm, more preferably the diameter of the first micropore 223 is 10.0 μm to 200 μm, and further preferably, the diameter of the first micropore 223 is 10.0 μm to 100 μm. The present invention does not limit the number of the first micropores 223, and does not limit the distribution mode of the first micropores 223, which can be uniformly distributed or unevenly distributed. In this embodiment, the first micropores 223 are evenly arranged around the longitudinal axis of the outer balloon 222, and several layers are provided along the longitudinal axis. In addition, the balloon catheter 200 of this embodiment is also provided with a retaining wall 224 on the first micropore 223. The implementation mode of the retaining wall 224 is the same as that of the first embodiment, and will not be described in detail.

[0069] In addition, the catheter body 210 is provided with a filling cavity (not shown) and a drug delivery cavity (not shown) which are isolated from each other. The filling cavity is communicated with the inner balloon 221, and the drug delivery cavity is communicated with the space between the outer balloon 222 and the inner balloon 221. The drug delivery cavity may wrap the filling cavity. The specific working principle is: the filling medium (preferably contrast agent) is delivered to the inner balloon 221 through the filling cavity, so that the inner balloon 221 and the outer balloon 222 expand until the outer balloon 222 fits tightly against the blood vessel wall. After expansion, the drug solution is continuously delivered between the inner balloon 221 and the outer balloon 222 through the drug delivery cavity. Under the pressure of the drug solution, the drug solution overflows into the blood vessel through the first micropore 223 on the outer balloon 222. In this process, the drug solution will pass through the buffering effect of the outer balloon 222 and the baffle wall 224, so that the speed of the drug solution sprayed at the first micropore 223 becomes smaller, and the direction of the drug solution flowing out of the first micropore 223 is no longer perpendicular to the blood vessel wall. Such a setting can effectively block the stimulation of the blood vessel wall by the liquid flow under high pressure, complete the perfusion of the drug solution in a gentle manner, and reduce the occurrence of vascular spasm. It should be known that Figure 7 The arrows shown in the figure represent the flow direction of the medicinal liquid and the flow direction of the filling medium respectively. In addition, after the medicinal liquid is perfused, the filling medium is withdrawn to retract the balloon 220, and finally the balloon catheter 200 is withdrawn from the body.

[0070] In this embodiment, the distal end of the drug delivery cavity has at least one drug delivery port, which is connected to the space between the outer balloon 222 and the inner balloon 221. The filling medium is preferably a contrast agent, so that the position of the balloon can be visualized by the contrast agent.

[0071] The other structures are basically the same as those in the first embodiment and will not be described in detail here. For details, please refer to the implementation method in the first embodiment.

[0072] Embodiment 3

[0073] This embodiment provides a method for preparing a balloon catheter, which is used to prepare the balloon catheter described in Embodiment 1 or Embodiment 2, and can also be used to prepare a balloon catheter with a single-layer balloon.

[0074] When preparing a balloon catheter with a single-layer balloon, first provide a catheter body and a single-layer balloon, and then sleeve the single-layer balloon on the catheter body. Then, open a plurality of micropores on the single-layer balloon, and set a retaining wall at each of the micropores. The retaining wall is configured to tilt toward the corresponding micropore after the single-layer balloon is expanded and at least partially cover the micropore. A drug solution channel is reserved between the retaining wall and the corresponding micropore, and the extension direction of the drug solution channel is not perpendicular to the longitudinal axis of the balloon catheter.

[0075] When preparing a balloon catheter with a double-layer balloon, first provide a catheter body and a double-layer balloon, wherein the double-layer balloon includes an inner balloon and an outer balloon, and a plurality of first micropores are opened on the outer balloon, and a plurality of second micropores are opened on the inner balloon, and a retaining wall is set at each of the first micropores, and then, the inner balloon and the outer balloon are sequentially sleeved on the catheter body, wherein the retaining wall is configured to tilt toward the corresponding first micropore after the double-layer balloon is expanded and at least partially cover the first micropore, and a drug solution channel is reserved between the retaining wall and the first micropore, and the extension direction of the drug solution channel is not perpendicular to the longitudinal axis of the balloon catheter.

[0076] Embodiment 4

[0077] After further research, the inventor found that during the use of the balloon catheter, the proximal and distal ends of the balloon are subjected to different pressures. The proximal end of the balloon has continuous blood pressure and blood flow scouring. The actual situation is that the outflowing liquid is more likely to flow to the distal end of the balloon. Based on this, in Example 4, the first micropores on the surface of the outer balloon are distributed in an uneven manner, that is, the number of first micropores distributed per unit area is inconsistent, or the pore size is inconsistent. This is done to allow the drug to diffuse evenly to the blood vessel wall. In a preferred embodiment, the distribution density of the first micropores at the proximal end of the balloon is higher than the distribution density of the first micropores at the distal end of the balloon. More preferably, the distribution density of the first micropores gradually decreases from the proximal end to the distal end of the balloon, that is, the first micropores at the proximal end are densely distributed, and the first micropores at the distal end are sparsely distributed. In another preferred embodiment, the aperture of the first micropore at the proximal end of the balloon is larger than the aperture of the first micropore at the distal end of the balloon. More preferably, the aperture of the first micropore gradually decreases from the proximal end to the distal end.

[0078] In another preferred embodiment, Fig. 9As shown, the opening of the baffle wall 125 corresponding to the first microhole near the proximal end of the balloon faces the proximal end of the balloon, that is, after the outer balloon 222 is expanded, the baffle wall 125 near the proximal end of the balloon is inclined toward the proximal end of the balloon, and the openings of the baffle wall 125 corresponding to the first microholes at other positions are all toward the center line L of the balloon (the center line is the transverse central axis), that is, the remaining baffle wall 125 is inclined toward the middle of the balloon. These designs can be used to relieve blood pressure and blood flow scour, reduce the loss of liquid medicine, and further improve the drug transfer rate. It should also be understood that these methods can be used alone or in combination.

[0079] It should be understood that the balloon catheter of the present invention is not only suitable for treating blood vessels, but also can be used for any human lumen, such as veins, aorta, etc., which need to be isolated, drained, supported, etc. Moreover, the drug is delivered in a liquid manner and contacts the target tissue area, which greatly reduces the delivery loss and improves the efficiency of drug transfer to the target tissue. In addition, it should be understood that the uniform diameter of the outer balloon or single-layer balloon of the present invention after expansion means that the diameters of the two ends of the balloon and the working areas at the two ends are the same. In this case, the balloon includes elliptical, cylindrical or spherical shapes. In addition, the micropores on the balloon can be punched perpendicular to the longitudinal axis of the balloon or along the radial direction of the balloon by a microinjection needle.

[0080] In summary, according to the technical solution provided by the embodiment of the present invention, the balloon catheter of the present invention is provided with a retaining wall at the first micropore of the outer balloon, which can buffer the liquid medicine through the retaining wall, not only reducing the injection speed of the liquid medicine, but also changing the injection direction of the liquid medicine, which can effectively block the stimulation of the blood vessel wall by the liquid flow under high pressure, complete the perfusion of the liquid medicine in a gentle manner, and reduce the occurrence of vascular spasm. In addition, the retaining wall is preferably inclined toward the middle of the balloon so that the liquid medicine is all injected toward the middle direction of the balloon. In this way, the diffusion direction of the liquid medicine is standardized, which can effectively reduce the loss of the liquid medicine flowing to the two ends and improve the drug transfer rate. Moreover, the diameter of the outer balloon after expansion is uniform, and there is no need to block the front and rear ends of the lesion during the intervention process, which avoids the formation of thrombus by residual blood and improves the safety of the device. In particular, in order to relieve blood pressure and blood flow scour, the distribution density of the micropores on the outer balloon is dense at the proximal end and sparse at the distal end, or the aperture of the micropores is large at the proximal end and small at the distal end. In particular, the opening of the baffle wall near the proximal end of the balloon is toward the proximal end of the balloon, and the remaining baffle walls are inclined toward the middle of the balloon, thereby reducing the loss of liquid medicine and further improving the drug transfer rate.

[0081] It should be understood that the above-mentioned embodiments specifically disclose the features of the preferred embodiments of the present invention so that those skilled in the art can better understand the present invention. Those skilled in the art should understand that, based on the disclosure of the present application document, it is easy to make appropriate modifications to the present invention to achieve the same purpose and / or achieve the same advantages as the embodiments disclosed in the present invention. Those skilled in the art should also recognize that such similar constructions do not depart from the scope disclosed in the present invention, and they can be variously changed, replaced and altered without departing from the scope disclosed in the present invention.

Claims

1. A balloon catheter, comprising a catheter body and a balloon, wherein the balloon is sleeved on the catheter body, characterized in that: The balloon includes at least one first balloon, which is provided with a plurality of first micropores, and a baffle wall is arranged at the first micropore; when the balloon is expanded, the baffle wall is inclined toward the corresponding first micropore to at least partially cover the first micropore, and a drug liquid channel is reserved between the baffle wall and the corresponding first micropore, and the extension direction of the drug liquid channel is not perpendicular to the longitudinal axis of the balloon catheter; when the balloon is expanded, the baffle wall close to the proximal end of the balloon is inclined toward the proximal end of the balloon, and the remaining baffle wall is inclined toward the middle of the balloon, or, when the balloon is expanded, all baffle walls are inclined toward the middle of the balloon; the balloon is made of non-compliant material or semi-compliant material.

2. The balloon catheter according to claim 1, characterized in that: The distribution density of the first micropores at the proximal end of the balloon is higher than the distribution density of the first micropores at the distal end of the balloon; and / or the pore size of the first micropores at the proximal end of the balloon is larger than the pore size of the first micropores at the distal end of the balloon.

3. The balloon catheter according to claim 1 or 2, characterized in that: The blocking wall is configured to be variable in position relative to the first microhole to adjust the extension direction of the drug solution channel.

4. The balloon catheter according to claim 1 or 2, characterized in that: The blocking wall is formed by extending outwards from the corresponding hole wall of the first microhole.

5. The balloon catheter according to claim 1 or 2, characterized in that: The balloon further comprises a second balloon, which is nested in the first balloon; a plurality of second micro-holes are formed on the second balloon; and the catheter body has a filling cavity; The filling chamber is used to deliver liquid medicine to the second balloon to expand the balloon. The filling chamber is also used to deliver liquid medicine to the second balloon so that the liquid medicine flows into the first balloon through a plurality of the second micropores under pressure and then flows out of the first balloon through a plurality of the first micropores.

6. The balloon catheter according to claim 5, characterized in that: The plurality of the second micropores and the plurality of the first micropores are staggered in the transverse direction of the balloon.

7. The balloon catheter according to claim 5, characterized in that: The pore size of the second micropores ranges from 5.0 μm to 500 μm, and the pore size of the first micropores ranges from 5.0 μm to 800 μm.

8. The balloon catheter according to claim 1 or 2, characterized in that: The balloon further comprises a second balloon, wherein the second balloon is nested in the first balloon; the catheter body comprises a filling cavity and a drug delivery cavity which are isolated from each other; The filling chamber is used to deliver a filling medium to the second balloon to expand the balloon; The drug delivery cavity is used to deliver liquid medicine to the first balloon, so that the liquid medicine flows out of the first balloon through the first micropores under pressure.

9. A method for preparing a balloon catheter, characterized in that: include: Providing a catheter body and a balloon, and sleeve the balloon on the catheter body; A plurality of microholes are formed on the balloon, and a retaining wall is arranged at each microhole; The retaining wall is configured to be inclined toward the corresponding micropore after the balloon is expanded to at least partially cover the micropore, and a liquid medicine channel is reserved between the retaining wall and the corresponding micropore, and the extension direction of the liquid medicine channel is not perpendicular to the longitudinal axis of the balloon catheter; When the balloon is expanded, the barrier wall near the proximal end of the balloon is inclined toward the proximal end of the balloon, and the remaining barrier walls are inclined toward the middle of the balloon, or, when the balloon is expanded, all the barrier walls are inclined toward the middle of the balloon.

10. The method for preparing a balloon catheter according to claim 9, characterized in that: When micropores are formed on the balloon, the distribution density of the micropores at the proximal end of the balloon is higher than that at the distal end of the balloon, and / or the pore size of the micropores at the proximal end of the balloon is larger than that of the micropores at the distal end of the balloon.

11. The method for preparing a balloon catheter according to claim 9, characterized in that: The diameter of the balloon after expansion remains uniform.

Images