Balloon catheter

Abstract

The present invention relates to a balloon catheter, which can release a liquid medicine through micropores on the balloon, enabling the liquid medicine to be absorbed by the target tissue. During the process of releasing the liquid medicine, it can also reduce the impact force formed by the liquid medicine on the inner wall of the body lumen, avoid the occurrence of lumen spasm, reduce the damage to the lumen, and at the same time reduce the loss of the drug during the transportation and perfusion processes, and improve the transfer rate of the drug.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly relates to a balloon catheter for intravascular drug delivery. Background Art

[0002] Coronary heart disease seriously affects human health. In June 2017, the data released in "Report on Cardiovascular Diseases in China 2016" showed that the prevalence and mortality of cardiovascular diseases in China are still on the rise. It is estimated that there are more than 11 million cases of coronary heart disease. Drug-eluting stents are the preferred treatment for coronary heart disease and are widely used. However, more and more evidence shows that in some cases, drug-coated balloons show advantages in comprehensive evaluation. Drug-coated balloons are a new interventional treatment technology. The drug-coated balloon attaches drugs that inhibit cell proliferation to the surface of the balloon. By inflating the balloon, the drugs are delivered into the local vascular wall of the lesion to achieve the effect of inhibiting smooth muscle proliferation.

[0003] In clinical applications, the balloon is inflated at the stenosis site for a certain period of time, and the drugs coated on the surface of the balloon contact the blood vessel wall, thereby transferring the drugs to the blood vessel wall to exert the therapeutic effect of the drugs. The general inflation time for using drug balloons is 30 seconds to 60 seconds, and all deliveries must be completed within 25 minutes. Since the contact time between the drugs on the balloon surface and the blood vessel wall is very short, the transfer and utilization of drugs are limited, and there are challenges in the efficacy of drug balloons. During the delivery and inflation of the balloon, a large amount of drugs will be lost: the drug loss during the delivery of the balloon in the blood vessel is about 10% to 25%, the actual transfer to the target tissue is about 1% to 10%, the entry into the distal circulation after balloon inflation is 60% to 70%, and the remaining on the balloon after inflation is 10% to 20%.

[0004] Therefore, how to reduce the large amount of drug loss during delivery and improve the efficiency of drug transfer to tissues is a problem that needs to be further solved for drug-coated balloons. Summary of the Invention

[0005] The purpose of the present invention is to provide a balloon catheter to solve the problems of a large amount of drug loss during the delivery of existing drug-coated balloons and low drug transfer efficiency, and at the same time ensure the safety of drug perfusion and reduce the damage to the internal lumen of the body.

[0006] To achieve the above purpose, a balloon catheter provided by the present invention includes a catheter body and a balloon disposed at the distal end of the catheter body; a plurality of micropores are provided on the surface of the balloon, and the micropores are used for releasing liquid medicine; when the balloon is inflated, the central axis of each micropore is inclined with respect to the longitudinal axis of the balloon catheter.

[0007] Optionally, after the balloon is inflated, at least one recessed area is defined on the surface of the balloon, and the micropores are disposed on the inclined surface of the recessed area.

[0008] Optionally, after the balloon is inflated, both the proximal end and the distal end of the balloon are conical, and the micropores are disposed on the conical surface at the proximal end of the balloon, and / or the micropores are disposed on the conical surface at the distal end of the balloon.

[0009] Optionally, the distribution density of the micropores on the conical surface at the proximal end of the balloon is greater than the distribution density of the micropores on the outer conical surface at the distal end of the balloon, and / or the pore diameter of the micropores on the conical surface at the proximal end of the balloon is greater than the pore diameter of the micropores on the conical surface at the distal end of the balloon.

[0010] Optionally, the recessed area has two inclined surfaces oppositely disposed in the axial direction of the balloon, and the micropores are disposed on each inclined surface.

[0011] Optionally, the recessed area is in an annular shape, and there are a plurality of the recessed areas, and the plurality of recessed areas are arranged at equal or unequal distances along the longitudinal axis of the balloon catheter.

[0012] Optionally, the balloon includes a plurality of sub-balloons connected end to end in sequence; both ends of each sub-balloon have tapered portions, and the tapered portions of any two adjacent sub-balloons are connected to form a recessed area at the connection position.

[0013] Optionally, the interiors of the plurality of sub-balloons communicate with each other; the catheter body has an axially extending drug delivery channel, and at least one drug delivery port is provided at the distal end of the drug delivery channel, and the drug delivery channel is used to deliver liquid medicine to each sub-balloon through at least one drug delivery port; wherein, at least one drug delivery port is provided inside the most distal sub-balloon, and / or at least one drug delivery port is provided inside the nearest sub-balloon.

[0014] Optionally, the interiors of the plurality of sub-balloons are isolated from each other; the catheter body has an axially extending drug delivery channel, and a plurality of drug delivery ports are provided at the distal end of the drug delivery channel, and the drug delivery channel is used to deliver liquid medicine to each sub-balloon through the plurality of drug delivery ports; wherein, each sub-balloon communicates with the drug delivery channel through at least one drug delivery port.

[0015] Optionally, the balloon is prepared by a hot blow molding process of a hollow pipe in a balloon mold, wherein the balloon mold has a mold cavity, and the shape of the mold cavity matches the shape of the balloon after inflation.

[0016] Optionally, the balloon catheter further includes a restraint structure disposed on the balloon. The restraint structure is made of an elastic material and fixed on the outer surface of the balloon, and the diameter of the restraint structure after inflation is smaller than the diameter of the balloon after inflation, so that a depression area is formed on the surface of the balloon under the restraint of the restraint structure after the balloon is inflated.

[0017] Optionally, there are a plurality of the restraint structures, and the plurality of restraint structures are arranged at equal or unequal distances along the longitudinal axis of the balloon catheter at intervals.

[0018] Optionally, the restraint structure is an elongate body and is bundled on the balloon, or the restraint structure is an annular body and is sleeved on the balloon.

[0019] The balloon catheter provided by the present invention has the following advantages:

[0020] First, after the balloon of the balloon catheter of the present invention is inflated, since the central axis of the micropores on the balloon is inclined relative to the longitudinal axis of the balloon catheter, when the liquid medicine is perfused into the balloon, the liquid medicine overflows from the micropores and can change direction, so that the liquid medicine is no longer released into the lumen in a direction perpendicular to the inner wall of the body lumen. With such a setting, the force formed by the perfused liquid medicine on the lumen wall is greatly reduced, thereby reducing the irritation to the lumen wall, thus reducing the occurrence of lumen wall spasm, and at the same time reducing the damage caused to the lumen wall by the impact of the liquid medicine, and improving the treatment effect;

[0021] Second, at least one depression area is defined on the surface of the balloon after inflation of the present invention, and micropores are opened on the inclined surface of the depression area. With such a setting, it is not only convenient for the processing of the micropores, but also beneficial for the balloon structures on both sides of the depression area to be closely attached to the lumen wall. Thus, by means of the extrusion action of the balloon structures on both sides of the depression area and the lumen wall, the liquid medicine can be more timely and effectively diffused into the target tissue, thereby increasing the drug transfer rate. At the same time, it is also convenient to store the liquid medicine through the depression area, reducing the loss of the liquid medicine flowing to both ends, and further increasing the drug transfer rate;

[0022] Third, the depression area of the present invention has two inclined surfaces that are oppositely arranged in the axial direction of the balloon, and micropores are provided on each inclined surface. By doing so, the inclination directions of the micropores on different inclined surfaces are exactly opposite, so that the liquid medicine can be sprayed both in the proximal direction of the balloon and in the distal direction of the balloon, and / or the distribution density of the micropores on the conical surface at the proximal end of the balloon is greater than the distribution density of the micropores on the conical surface at the distal end of the balloon, and / or the pore diameter of the micropores on the conical surface at the proximal end of the balloon is greater than the pore diameter of the micropores on the conical surface at the distal end of the balloon. These methods can all make the drug evenly diffuse into the target tissue, relieve the influence of the blood flow pressure and blood flow scouring at the proximal end of the balloon, reduce the loss of the liquid medicine, and further increase the drug transfer rate. Description of the Drawings

[0023] Those of ordinary skill in the art will understand that the provided drawings are used to better understand the present invention and do not constitute any limitation to the scope of the present invention. In the drawings:

[0024] Figure 1 is a schematic structural diagram of an exemplary balloon catheter of the present invention;

[0025] Figure 2 is Figure 1 a partial enlarged view of the shown balloon catheter;

[0026] Figure 3 is a diagram of the use state of an exemplary balloon catheter of the present invention;

[0027] Figure 4 is a schematic diagram of preparing a balloon with a concave area through a constraint structure in the first embodiment of the present invention;

[0028] Figure 5 is Figure 4 a sectional view taken along the line A-A shown;

[0029] Figure 6 is a schematic diagram of preparing a balloon with a concave area through a balloon mold in the second embodiment of the present invention.

[0030] In the figures: balloon catheter 10; catheter body 11; balloon 12; concave area 121; inclined surface 122; micropore 123; longitudinal axis L1 of the balloon catheter; tangent line L2 of the inclined surface; central axis L3 of the micropore; angle α between the tangent line of the inclined surface and the longitudinal axis of the balloon catheter; angle β between the central axis of the micropore and the longitudinal axis of the balloon catheter; blood vessel wall S; constraint structure 13; conical shape 124 at the proximal end of the balloon; conical shape 125 at the distal end of the balloon; balloon mold 20; mold cavity 21.

[0031] In the drawings, the same or similar reference numerals represent the same or similar components. Detailed Embodiments

[0032] The following uses specific specific examples to illustrate the embodiments 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. The 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 drawings provided in this embodiment only illustrate the basic concept of the present invention schematically. Therefore, only the components related to the present invention are shown in the drawings, rather than being drawn according to the number, shape, and size of the components in actual implementation. The types, quantities, and proportions of the components in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0033] In addition, each of the embodiments of the following description content has one or more technical features. However, this does not mean that the inventor must implement all the technical features in any one embodiment at the same time, or can only separately implement some or all of the technical features in different embodiments. In other words, on the premise that implementation is possible, those skilled in the art can, according to the disclosure of the present invention and depending on the design specifications or implementation requirements, selectively implement some or all of the technical features in any one embodiment, or selectively implement the combination of some or all of the technical features in multiple embodiments, thereby increasing the flexibility when implementing the present invention.

[0034] 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 accompanying drawings are all in a very simplified form and use non-precise scales, and are only used to conveniently and clearly assist in explaining the objectives of the embodiments of the present invention. As used in this specification, the singular forms "a", "an" and "the" include plural objects unless the context clearly indicates otherwise. As used in this specification, the meaning of "plural" generally includes two or more unless the context clearly indicates otherwise. As used in this specification, the term "or" is generally used in the sense of including "and / or" unless the context clearly indicates otherwise. The term "axial direction" generally refers to the direction parallel to the longitudinal axis of the balloon catheter; "proximal end" generally refers to the direction close to the operator of the balloon catheter; "distal end" refers to the direction away from the operator of the balloon catheter. It should also be understood that the present invention repeats reference numerals 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 there can be one or more intermediate elements.

[0035] The core idea of the present invention is to provide a balloon catheter for intravascular administration. The balloon catheter includes a catheter body and a balloon provided at the distal end of the catheter body. Among them, a plurality of micropores are provided on the surface of the balloon, and the micropores are used to release the liquid medicine. In particular, when the balloon expands, the central axis of each micropore is inclined with respect to the longitudinal axis of the balloon catheter. By setting it like this, the micropores can be set by using the inclined surface formed on the surface of the balloon, so that the central axis of the micropore forms an angle less than 90° with the longitudinal axis of the balloon catheter, thereby changing the direction and angle of the micropore, thereby reducing the stimulating effect of the liquid medicine on the inner lumen wall of the body, thereby reducing the occurrence of lumen spasm and the damage caused to the lumen wall, and improving the treatment effect.

[0036] It should be understood that the balloon catheter 10 of the present invention is not limited to interventional blood vessels. Whenever it is necessary to deliver drugs or other substances for treatment in human body lumens such as the esophagus, bile duct, uterus and its appendages, prostate, etc., the balloon catheter of the present invention can be used.

[0037] The following will describe in detail the structure and usage mode of the balloon catheter proposed by the present invention with reference to the accompanying drawings and preferred embodiments.

[0038] Figure 1 It is a schematic structural diagram of an exemplary balloon catheter of the present invention. Figure 2 is Figure 1 a partial enlarged view of the balloon catheter in. As Figure 1 shown, the embodiment of the present invention relates to a balloon catheter 10, which includes a catheter body 11 and a balloon 12 provided at the distal end of the catheter body 11. Among them, after the balloon 12 is fully inflated, a bevel 122 is formed on the outer surface of the balloon 12. As Figure 2 shown, the bevel 122 forms an angle α with the longitudinal axis L1 of the balloon catheter, and α is less than 90° and greater than 0°. It should be understood that the bevel 122 is usually an arc surface. Therefore, α is the angle between the tangent line L2 of the bevel 122 and the longitudinal axis L1 of the balloon catheter. And a plurality of micropores 123 are provided on the bevel 122, and the micropores 123 are used to release the liquid medicine. Moreover, after the balloon 12 is fully inflated, the central axis L3 of each micropore 123 forms an angle β with the longitudinal axis L1 of the balloon catheter, and β is complementary to α, that is, the micropores 123 are opened in a direction perpendicular to the bevel 122.

[0039] In order to form the bevel 122, in some embodiments, when the balloon 12 is fully inflated, at least one recessed area 121 is defined on the surface of the balloon 12, and the recessed area 121 has a bevel 122, so that the micropores 123 can be provided on the bevel 122 of the recessed area 121. In some embodiments, when the balloon 12 is inflated, both the proximal end and the distal end of the balloon 12 are conical, and micropores 123 are provided on the surface of the conical shape 124 at the proximal end of the balloon and / or the conical shape 125 at the distal end of the balloon. Here, since the surface of the conical shape is also the bevel 122, the micropores 123 can also be provided on the surface of the conical shapes at both ends of the balloon according to needs. The position of the bevel 122 on the balloon 12 should be set according to the actual lesion position. Generally, in order to achieve a better treatment effect, the micropores 123 can be provided on the bevel 122 of the recessed area 121. Further, it is also preferred to provide the micropores 123 on the surface of the conical shapes at both ends of the balloon. In an alternative embodiment, the surface of the balloon can also be formed with protrusions to construct the bevel 122 through the protrusions. The structural manner of the protrusions is similar to that of the recessed area and will not be described in detail.

[0040] Figure 3This is a usage state diagram of an exemplary balloon catheter of the present invention. As Figure 3 shown, when the liquid medicine is perfused inside the balloon 12, along the directions indicated by the solid arrows, the liquid medicine overflows from each micropore 123. Since the central axis of each micropore 123 is not perpendicular to the blood vessel wall S, the spraying direction of the liquid medicine is no longer perpendicular to the blood vessel wall S. Thereby, the impact force of the liquid medicine spraying is reduced, the irritation of the liquid medicine spraying to the blood vessel wall is reduced, the occurrence of vasospasm is prevented, and the damage to the blood vessel wall is also reduced. In particular, the balloon structures on both sides of the recessed area 121 can be closely attached to the blood vessel wall S, so as to utilize the squeezing effect generated by the balloon structures on both sides of the recessed area 121 and the blood vessel wall S to promote the liquid medicine to diffuse into the blood vessel tissue in time. Thereby, the drug transfer rate is improved. Moreover, the recessed area 121 can also store the liquid medicine, reduce the loss of the liquid medicine flowing to both ends, and further improve the drug transfer rate.

[0041] To further improve the drug transfer rate, the distribution density of the micropores 123 on the conical shape 124 at the proximal end of the balloon is preferably greater than the distribution density of the micropores 123 on the conical shape 125 at the distal end of the balloon, and / or the aperture of the micropores 123 on the conical shape 124 at the proximal end of the balloon is preferably greater than the aperture of the micropores 123 on the conical shape 125 at the distal end of the balloon. These methods can relieve the blood pressure and blood flow scouring, and reduce the loss of the liquid medicine. Further, the recessed area 121 preferably has two inclined surfaces 122 oppositely arranged in the axial direction of the balloon 12, and a plurality of micropores 123 are arranged on each inclined surface 122 of the recessed area 121. The central axis of the micropores 123 on any inclined surface 123 is perpendicular to the tangent plane of the inclined surface 123. Therefore, by arranging the micropores 123 on the two opposite inclined surfaces 122 of the same recessed area 121, the liquid medicine can be sprayed both in the proximal direction and the distal direction of the balloon. Such a method can also make the drug evenly diffuse to the blood vessel wall, relieve the influence of the blood flow pressure and blood flow scouring on the proximal end of the balloon, reduce the loss of the liquid medicine, and further improve the drug transfer rate.

[0042] The present invention does not limit the number of micropores 123 provided on each inclined surface 122, nor does it limit the distribution pattern of the micropores 123 on each inclined surface 122. The micropores 123 can be evenly distributed or unevenly distributed. In this embodiment, the micropores 123 on the same inclined surface 122 are preferably arranged evenly around the longitudinal axis of the balloon catheter. The present invention does not particularly limit the pore diameter of the micropores 123. For example, the pore diameter range of the micropores 123 can be selected from 5.0 μm to 500 μm, preferably 10.0 μm to 250 μm, and more preferably 10.0 μm to 50 μm. Further, the number of micropores 123 on the balloon 12 can be selected from 5 to 100, preferably 5 to 50. Further, the angle β between the central axis L3 of the micropore 123 and the longitudinal axis L1 of the balloon catheter can be selected to be not more than 89°, preferably not more than 60°, and more preferably not more than 30°. Here, it should be understood that a "micropore" refers to a hole with a size in the micrometer range. The present invention does not limit the shape of the micropores 123. For convenience of processing, circular micropores are preferably used. Further, the recessed area 121 is preferably in an annular shape (i.e., a continuous and uninterrupted circle of recesses). More preferably, there are multiple (multiple includes 2) recessed areas 121, and the multiple recessed areas 121 are arranged at equal or unequal distances along the longitudinal axis of the balloon catheter. In this case, the micropores 123 on the multiple inclined surfaces 122 with the same inclination direction on different recessed areas 121 are arranged in multiple layers along the longitudinal axis of the balloon catheter. In this embodiment, the multiple recessed areas 121 are preferably arranged at equal distances along the longitudinal axis of the balloon catheter, which is beneficial for uniform diffusion to the vascular tissue and reduces the loss of the liquid medicine.

[0043] The balloon 12 can be made of a polymer elastic material, and further preferably a non-compliant or semi-compliant material. The advantage of a non-compliant or semi-compliant material is that as the pressure increases, the balloon 12 stops expanding when it reaches the specified size and does not expand further with the increase of pressure, thus avoiding damage to the blood vessel caused by over-expansion of the balloon. For example, the material for preparing the balloon 12 can be selected from PEBAX (polyether block polyamide), polyethylene, polyamide, etc. The balloon 12 can be a balloon for angioplasty and any other balloon used in interventional cardiovascular methods.

[0044] The present invention does not limit the types of drugs to be delivered. For example, it can be drugs that inhibit cell proliferation, anti-inflammatory drugs, anti-inflammatory drugs, antibacterial drugs, anti-tumor drugs, anti-mitotic drugs, anti-osteoporosis drugs, anti-angiogenic drugs, etc. Moreover, it can be a combination of multiple drugs. Schematically, the drug is, for example, one or a combination of mTOR inhibitors (everolimus), paclitaxel and its derivatives, antiplatelet drugs, cilostazol, ticlopidine, triptolide, dexamethasone, methotrexate, fluorouracil, mercaptopurine, hydroxyurea, cytarabine, carboplatin, cisplatin, oxaliplatin, bicisplatin, daunorubicin, doxorubicin, and arsenic trioxide. The mTOR inhibitor can be one or a combination of rapamycin (sirolimus), everolimus, deforolimus, temsirolimus, and zotarolimus.

[0045] Further, in order to more clearly understand the preparation method of the balloon of the present invention, the following further description will be made by taking Examples 1 to 4 as examples, but the preparation methods of the following examples should not be used as a limitation on the preparation method of the balloon of the present invention.

[0046] Example 1

[0047] Figure 4 is the schematic diagram of preparing a balloon with a concave area through a constraint structure in Example 1 of the present invention. Figure 5 is Figure 4 the cross-sectional view along the line A-A in

[0048] As Figures 4-5 shown, the balloon catheter 10 of this embodiment further includes a constraint structure 13. By using the constraint structure 13, the entire balloon 12 can be constrained into Figure 4 the structural state shown, so as to obtain a balloon 12 with a concave area 121. The constraint structure 13 is fixed on the outside of the balloon 12 and can expand as the balloon 12 is filled. Moreover, the diameter of the constraint structure 13 after expansion is smaller than the diameter of the balloon 12 after expansion. Thus, when the balloon 12 is fully expanded, under the restraint of the constraint structure 13, a concave area 121 can be formed on the balloon surface.

[0049] The constraint structure 13 is mainly made of elastic materials, including but not limited to materials such as nickel-titanium metal, elastic polymers, or high-strength fibers. Preferably, there are multiple constraint structures 13, and the multiple constraint structures 13 are arranged at equal or unequal distances at intervals along the longitudinal axis of the balloon catheter, and more preferably arranged at equal distances along the longitudinal axis of the balloon catheter. In some embodiments, the constraint structure 13 can be an elongated body such as a wire, rope, thread, or belt, and can be directly tied to the balloon 12. In other embodiments, the constraint structure 13 can be an annular body, for example, a constraint ring sleeved on the balloon 12.

[0050] Taking the restraint ring as an example, when the balloon 12 is not fully inflated, the restraint ring can be sleeved onto the balloon 12, and the restraint ring can be adhesively fixed to the balloon 12 by using a hot blow molding process. After that, the balloon 12 is continuously inflated until the balloon 12 is fully inflated. After the balloon 12 is fully inflated, since the diameter of the restraint ring after inflation (such as 2.0 mm) is smaller than the diameter of the balloon 12 after inflation (such as 3.0 mm), a circular depression area 121 is formed on the surface of the balloon 12 due to the restraint effect of the restraint ring. Then, a Hamilton micro-syringe needle is used to vertically punch holes on the inclined surface 122 of the depression area 121, and the micropores 123 can be obtained. In this embodiment, as Figure 5 shown, four micropores 123 can be equidistantly punched around the longitudinal axis of the balloon catheter on the inclined surface 122 of the balloon 12.

[0051] It should be known that the axial length of the balloon 12 is mainly set according to the length of the diseased blood vessel. Therefore, the present invention does not limit the axial length of the balloon 12, nor does it limit the number of the restraint structures 13. Exemplarily, the axial length of the balloon 12 after full inflation can be 20 mm, and 4 restraint rings can be used to form 4 depression areas 121 on the surface of the balloon 12. The 4 depression areas 121 are equidistantly distributed. In addition, the material of the restraint ring can be selected from nylon.

[0052] Embodiment Two

[0053] Figure 6 is the schematic diagram of preparing a balloon with a depression area through a balloon mold in the second embodiment of the present invention.

[0054] As Figure 6 shown, this embodiment provides a balloon mold 20. The shape of the cavity 21 of the balloon mold 20 matches the shape of the balloon 12 after inflation. During actual preparation, a balloon 12 with a depression area 121 can be prepared by using a hollow pipe in the balloon mold 20 through a hot blow molding process. After that, when the balloon 12 is fully inflated, a Hamilton micro-syringe needle is used to punch holes on the inclined surface 122 of the depression area 121, and the micropores 123 can be obtained.

[0055] Embodiment Three

[0056] In Embodiment Three, the balloon 12 includes a plurality of sub-balloons (not shown) connected end to end in sequence. Each sub-balloon has tapered portions at both ends, and the tapered portions of any two adjacent sub-balloons are connected to form a depression area 121 at the connection position. That is, the depression area 121 is formed by splicing the tapered portions of two adjacent sub-balloons. More specifically, a plurality of sub-balloons are taken, the tapered portions (i.e., tapered pipe sections) at both ends of the plurality of sub-balloons are cut, and the tapered portions of adjacent sub-balloons are hot-melt connected by using a heat gun. After that, a Hamilton micro-syringe needle is used to vertically punch holes on the tapered portions, and the micropores 123 can be obtained.

[0057] The present invention does not limit the number of sub-balloons. Specifically, the number of sub-balloons is set according to the length of the lesion site so that the length of the entire balloon can meet the treatment requirements. For example, in this embodiment, the length of each sub-balloon is 5.0 mm, the number is 6, and the diameter of each sub-balloon after complete inflation is 3.0 mm.

[0058] In a preferred embodiment, the interiors of the plurality of sub-balloons communicate with each other. The catheter body 11 has an axially extending drug delivery channel (not shown), and at least one drug delivery port (not shown) is provided at the distal end of the drug delivery channel, so that the drug solution is simultaneously delivered to each sub-balloon through the drug delivery channel by at least one of the drug delivery ports. Preferably, at least one of the drug delivery ports is provided inside the sub-balloon at the distal end, that is, the interior of the sub-balloon at the most distal end communicates with the drug delivery channel through at least one drug delivery port, so that the drug solution flows from the distal end of the balloon to the proximal end of the balloon, causing each sub-balloon to be filled and expanded. Alternatively, at least one of the drug delivery ports is provided inside the sub-balloon at the proximal end, that is, the interior of the sub-balloon at the nearest proximal end communicates with the drug delivery channel through at least one drug delivery port, so that the drug solution flows from the proximal end of the balloon to the distal end of the balloon, causing each sub-balloon to be filled and expanded. Or, at least one drug delivery port is provided inside the balloon at the most distal end, and at least one drug delivery port is provided inside the balloon at the nearest proximal end at the same time.

[0059] In another preferred embodiment, the interiors of the plurality of sub-balloons may also be isolated from each other, that is, not communicating with each other. At this time, the catheter body 11 has an axially extending drug delivery channel, and a plurality of drug delivery ports are provided at the distal end of the drug delivery channel, so that the drug solution is delivered to each sub-balloon through the drug delivery channel by the plurality of drug delivery ports, and each sub-balloon communicates with the drug delivery channel through at least one drug delivery port.

[0060] Example 4

[0061] In Example 4, the damage to the blood vessel wall of the existing perfusion drug balloon and the balloon catheter of the present invention was compared in an in vitro test. During the test, there was no concave area on the surface of the existing perfusion drug balloon, and 40 holes were punched perpendicular to the balloon surface using a Hamilton micro-syringe needle, and the holes were evenly distributed on the balloon surface. The balloon catheter of the present invention was tested using the sample prepared in Example 1, and 40 holes were also punched on the balloon surface, and the holes were evenly distributed on the balloon surface, and the aperture of the holes was the same as that of the holes on the existing perfusion drug balloon.

[0062] During the test, porcine coronary arteries were taken for in vitro experiments. The existing drug perfusion balloon and the balloon catheter of the present invention were respectively connected to a pressure pump, placed into the blood vessels, and physiological saline was used as the perfusion liquid. After the pressure was increased to 10 atmospheres, perfusion was maintained for 1 minute. After perfusion, the blood vessels were longitudinally incised, and the damage to the vascular endothelium was observed under a dissecting microscope. The results showed that the existing drug perfusion balloon caused a large area of congestion damage to the endothelium due to the direct vertical impact of the drug solution on the blood vessel wall, while no obvious damage was found in the balloon catheter of the present invention because the drug solution did not vertically impact the blood vessel wall. Therefore, the safety of the balloon catheter of the present invention is superior to that of the existing drug perfusion balloon.

[0063] Therefore, after applying the balloon catheter of the present invention, during the process of perfusing the drug solution into the body lumen, the force formed by the drug solution on the lumen wall can be greatly reduced, thereby reducing the irritation to the lumen wall, preventing the occurrence of lumen spasm, and at the same time reducing the damage caused by the impact of the drug solution on the lumen wall and improving the treatment effect. In addition, by providing a recessed area on the surface of the balloon, not only is it convenient for the processing of micropores, but also it is beneficial for the balloon structures on both sides of the recessed area to closely fit the blood vessel wall. Thus, with the extrusion effect of the balloon structures on both sides of the recessed area and the blood vessel wall, the drug solution can be more timely and effectively diffused into the vascular tissue, thereby improving the drug transfer rate. At the same time, it is also convenient to store the drug solution through the recessed area, reducing the loss of the drug solution flowing to both ends and further improving the drug transfer rate. Additionally, it should be noted that the present invention does not limit the axial cross-sectional shape of the recessed area, including but not limited to a V shape. Furthermore, the constraint structure is not limited to being fixed to the balloon through a hot blow molding process.

[0064] It should be understood that the above embodiments specifically disclose the features of the 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 disclosed content of this application document, it is easy to make appropriate modifications to the present invention to achieve the same purpose and / or the same advantages as the disclosed embodiments of the present invention. Those skilled in the art should also recognize that such similar structures do not deviate from the scope of the present invention disclosed, and they can be subject to various changes, substitutions, and alterations without departing from the scope of the present invention disclosed.

Claims

1. A balloon catheter, characterized in that, it includes a catheter body and a balloon provided at the distal end of the catheter body; a plurality of micropores are provided on the surface of the balloon, and the micropores are used for releasing a liquid medicine; when the balloon expands, the central axis of each micropore is inclined with respect to the longitudinal axis of the balloon catheter, and the central axis of each micropore forms an angle β with the longitudinal axis of the balloon catheter, and an inclined surface is formed on the outer surface of the balloon, and the inclined surface forms an angle α with the longitudinal axis of the balloon catheter, α is less than 90° and greater than 0°, and β and α are complementary angles; when the balloon expands, both the proximal end and the distal end of the balloon are conical, and the micropores are provided on the surface of the conical shape at the proximal end of the balloon, and the micropores are provided on the surface of the conical shape at the distal end of the balloon, the distribution density of the micropores on the surface of the conical shape at the proximal end of the balloon is greater than the distribution density of the micropores on the surface of the conical shape at the distal end of the balloon, and the pore diameter of the micropores on the surface of the conical shape at the proximal end of the balloon is greater than the pore diameter of the micropores on the surface of the conical shape at the distal end of the balloon.

2. The balloon catheter according to claim 1, characterized in that, when the balloon expands, at least one concave area is defined on the surface of the balloon, and the micropores are provided on the inclined surface of the concave area.

3. The balloon catheter according to claim 2, characterized in that, the concave area has two inclined surfaces oppositely arranged in the axial direction of the balloon, and the micropores are provided on each inclined surface.

4. The balloon catheter according to claim 3, characterized in that, the concave area is in an annular shape, and there are a plurality of the concave areas, and the plurality of concave areas are arranged at equal or unequal distances at intervals along the longitudinal axis of the balloon catheter.

5. The balloon catheter according to any one of claims 2-4, characterized in that, the balloon includes a plurality of sub-balloons connected end to end in sequence; both ends of each sub-balloon have tapered portions, and the tapered portions of any two adjacent sub-balloons are connected to form a concave area at the connection position.

6. The balloon catheter according to claim 5, characterized in that, the interiors of the plurality of sub-balloons communicate with each other; the catheter body has an axially extending medicine delivery channel, and at least one medicine delivery port is provided at the distal end of the medicine delivery channel, and the medicine delivery channel is used for delivering the liquid medicine to each sub-balloon through at least one medicine delivery port; wherein, at least one medicine delivery port is provided inside the most distal sub-balloon, and / or, at least one medicine delivery port is provided inside the nearest sub-balloon.

7. The balloon catheter according to claim 5, characterized in that, the interiors of the plurality of sub-balloons are isolated from each other; the catheter body has an axially extending medicine delivery channel, and a plurality of medicine delivery ports are provided at the distal end of the medicine delivery channel, and the medicine delivery channel is used for delivering the liquid medicine to each sub-balloon through the plurality of medicine delivery ports; wherein, each sub-balloon communicates with the medicine delivery channel through at least one medicine delivery port.

8. The balloon catheter according to any one of claims 2-4, characterized in that, The balloon is prepared by a hot blow molding process of a hollow pipe in a balloon mold. Among them, the balloon mold has a cavity, and the shape of the cavity matches the shape of the balloon after inflation.

9. The balloon catheter according to any one of claims 2-4, characterized in that the balloon catheter further includes a constraint structure provided on the balloon. The constraint structure is made of an elastic material and fixed on the outer surface of the balloon, and the diameter of the constraint structure after inflation is smaller than the diameter of the balloon after inflation, so that a depression area is formed on the surface of the balloon under the restraint of the constraint structure after the balloon is inflated.

10. The balloon catheter according to claim 9, characterized in that there are a plurality of the constraint structures, and the plurality of constraint structures are arranged at equal or unequal distances along the longitudinal axis of the balloon catheter at intervals.

11. The balloon catheter according to claim 9, characterized in that the constraint structure is an elongated body and is bundled on the balloon, or the constraint structure is an annular body and is sleeved on the balloon.

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