Drug balloon dilation catheter

Abstract

The utility model discloses a kind of drug balloon dilatation catheter, drug is the drug of inhibiting vascular intima hyperplasia, including balloon, the stent of coating in the outside of balloon, the drug-loaded microsphere particle layer of being set on the outer surface of balloon, balloon and stent all have the shrinkage state for being placed in blood vessel and the expansion state for being expanded in blood vessel, and the maximum diameter of stent under expansion state is less than the maximum diameter of balloon, stent has a plurality of interval settings mesh along longitudinal direction and peripheral direction, in shrinkage state, drug-loaded microsphere particle layer is housed between balloon and stent;In expansion state, balloon and at least part of drug-loaded microsphere particle layer located on it are inflated to the outside of stent from each mesh.The dilatation catheter can isolate blood from drug-loaded microsphere particle layer by stent when conveying, can avoid blood scouring drug-loaded microsphere particle layer to make drug-loaded microsphere particle layer loss in conveying process, to improve the transfer efficiency of drug to blood vessel.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, specifically to a drug-eluting balloon dilation catheter. Background Technology

[0002] Obstruction of blood vessels is a common disease, such as peripheral artery disease (PAD), which generally refers to various arterial diseases other than coronary arteries and intracranial arteries. One of the main treatments for PAD is angioplasty, using a balloon catheter. Angioplasty is performed using a balloon to reshape the blood vessel pathway, or to perform pre-dilation and post-dilation procedures while ensuring vascular access through stent deployment.

[0003] Traditional balloon dilation of narrowed blood vessels can damage the intima, leading to adverse consequences such as aortic dissection and restenosis. Applying drugs like paclitaxel or rapamycin to the balloon surface can inhibit intimal hyperplasia and reduce these adverse effects. However, existing drug-eluting balloons suffer from significant drug loss during vascular delivery, reducing the efficiency of drug transfer into the blood vessel. Summary of the Invention

[0004] The purpose of this invention is to provide a drug balloon dilation catheter that can reduce drug loss during delivery and improve the efficiency of drug transfer to blood vessels, addressing the problems in the prior art.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A drug-eluting balloon dilatation catheter includes a balloon, the drug being a drug that inhibits vascular intimal hyperplasia, and a stent covering the outside of the balloon and a drug-loaded microsphere layer disposed on the outer surface of the balloon. Both the balloon and the stent have a contracted state for insertion into a blood vessel and an expanded state for expansion within the blood vessel. In the expanded state, the maximum diameter of the stent is smaller than the maximum diameter of the balloon. The stent has a plurality of spaced mesh openings along its longitudinal and circumferential directions. In the contracted state, the drug-loaded microsphere layer is housed between the balloon and the stent; in the expanded state, at least a portion of the balloon and the drug-loaded microsphere layer thereon protrude from each of the mesh openings to the outside of the stent.

[0006] In some embodiments, in the expanded state, the mesh openings are arranged in an array along the longitudinal and circumferential directions of the support.

[0007] In some embodiments, the stent includes a main body and connecting portions respectively disposed at both ends of the main body for connection with the balloon. The main body includes longitudinal rods extending in a longitudinal direction, and a plurality of longitudinal rods are spaced apart in a circumferential direction. The main body also includes transverse rods connected between each pair of adjacent longitudinal rods. A plurality of transverse rods are spaced apart in the longitudinal direction between each pair of adjacent longitudinal rods and between each pair of adjacent transverse rods. A mesh is formed between each pair of adjacent longitudinal rods and each pair of adjacent transverse rods. Each longitudinal rod and each transverse rod is capable of expanding and contracting with the balloon.

[0008] In some embodiments, the connection points of each of the transverse bars on two adjacent longitudinal bars are located at different positions in the longitudinal direction.

[0009] In some embodiments, adjacent ends of two adjacent transverse bars are connected in the circumferential direction, or connected at the same location on the longitudinal bar.

[0010] In some embodiments, the connecting portion includes a connecting rod extending in the longitudinal direction, and multiple connecting rods are spaced apart in the circumferential direction. In each connecting portion, the number of connecting rods is not greater than the number of longitudinal rods. One end of each connecting rod is connected to or integrally formed with a different longitudinal rod. The connecting rods are capable of expanding and contracting with the balloon.

[0011] In some embodiments, in the contracted state, the area of ​​the mesh openings is less than or equal to 7 mm². 2 In the expanded state, the area of ​​the mesh is 7~25mm. 2 The height of the portion of the balloon protruding outside the stent is 0.02-2 mm.

[0012] In some embodiments, the thickness of the drug-loaded microsphere layer is 0.06 mm to 0.8 mm, and the drug-loaded microsphere layer includes a plurality of drug-loaded microspheres, each of which has a size of 200 nm to 100 μm.

[0013] In some embodiments, the size of each drug-loaded microsphere is less than 1 μm, or greater than or equal to 1 μm but less than 10 μm, or greater than or equal to 10 μm but less than 100 μm.

[0014] In some embodiments, the drug is paclitaxel or rapamycin; the drug-loaded microsphere layer is a biodegradable microsphere layer.

[0015] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art: In the drug-eluting balloon dilation catheter of this utility model, a stent is provided outside the balloon, which can maintain a better expansion length, expansion diameter, and expansion speed when the balloon expands in the blood vessel, avoiding excessive and rapid expansion of the blood vessel and reducing the radial and longitudinal forces of the balloon on the blood vessel wall. Moreover, when the dilation catheter is delivered in the blood vessel, the stent can separate the blood from the drug-loaded microsphere layer, which can prevent the blood from washing away the drug-loaded microsphere layer and causing it to be lost during delivery, thereby improving the efficiency of drug transfer into the blood vessel. Attached Figure Description

[0016] Figure 1 This is a frontal view of the drug-eluting balloon dilation catheter in this embodiment when it is not dilated; Figure 2 for Figure 1 Enlarged view of a portion of point A in the middle; Figure 3 for Figure 1 Enlarged view of a portion of point B in the middle; Figure 4 This is a frontal view of the drug-eluting balloon dilation catheter in the dilated state according to this embodiment; Figure 5 This is a side view of the drug-eluting balloon dilation catheter in the dilated state according to this embodiment; Figure 6 This is one of the schematic diagrams showing the morphology of the drug-loaded microspheres in the drug-eluting balloon dilation catheter of this embodiment; Figure 7 This is the second schematic diagram of the morphology of the drug-loaded microspheres in the drug balloon dilation catheter of this embodiment.

[0017] The components are: 1. outer tube; 2. inner tube; 3. balloon; 31. protrusion; 4. support; 41. longitudinal rod; 42. transverse rod; 43. connecting rod; 5. tip tube; 6. drug-loaded microspheres; 7. imaging ring. Detailed Implementation

[0018] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0019] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model patent product is in use. They are only for the convenience of describing this utility model patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model patent. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0020] Unless otherwise specified, the terms "proximal end" and "distal end" mentioned in this utility model have the same meaning in terms of orientation. That is, in the state of use, the distal end is the end away from the operator, and the proximal end is the end closer to the operator. The operator controls the drug balloon dilation catheter at the proximal end.

[0021] like Figure 1 and Figure 4 As shown, the drug-eluting balloon dilation catheter of this invention includes an outer tube 1, an inner tube 2, a balloon 3, a stent 4, and a drug-loaded microsphere layer.

[0022] The proximal portion of the inner tube 2 is inserted into the lumen of the outer tube 1, and the distal portion of the inner tube 2 is fitted with a pointed tube 5.

[0023] The balloon 3 is fitted over the inner tube 2, with its proximal end connected to the distal end of the outer tube 1, and its distal end connected to the proximal end of the tip tube 5. The stent 4, in a tubular structure, covers the outside of the balloon 3, with its proximal end connected to the proximal end of the balloon 3, and its distal end connected to the distal end of the balloon 3. The balloon 3 can be connected to the outer tube 1, the tip tube 5, and the stent 4 by adhesive bonding or thermal fusion.

[0024] The balloon 3 is a semi-compliant balloon, and its diameter can increase with the increase of the pressure inside the balloon cavity. The balloon 3 can be made of nylon material.

[0025] The stent 4 expands and contracts in sync with the balloon 3. Both the balloon 3 and the stent 4 have a contracted state for insertion into the blood vessel and an expanded state for expansion within the vessel. During expansion, the expansion diameter of the stent 4 is smaller than that of the balloon 3. Thus, the stent 4 restricts the balloon 3 to maintain optimal expansion length and diameter during expansion within the vessel. Simultaneously, the balloon 3 expands gently and uniformly due to the restriction of the stent 4, preventing excessively rapid or excessive expansion of the vessel and reducing the radial and longitudinal forces exerted by the balloon 3 on the vessel wall. Furthermore, the stent 4 also provides positioning, preventing the balloon 3 from rotating or shifting relative to the diseased vessel, ensuring uniform shear force on the vessel wall, and reducing the probability of vascular damage and complications.

[0026] The stent 4 has multiple spaced mesh openings along its longitudinal and circumferential directions, allowing a portion of the balloon 3 to protrude from the mesh openings onto the outside of the stent 4 when the dilation catheter is in the dilated state. When the stent 4 is in the constricted state, the area of ​​the mesh openings is less than or equal to 7 mm². 2 When the support 4 is in its expanded state, the area of ​​the mesh is 7~25mm. 2 The balloon 3 bulges out from each mesh hole to the outside of the support 4 to form multiple protrusions 31, the height of which is 0.02-2mm.

[0027] Specifically, the stent 4 includes a main body and a connecting part. The connecting part is located at the distal end and proximal end of the main body, respectively. The connecting parts located at both ends of the main body are connected to the balloon 3, and multiple mesh holes are provided on the main body.

[0028] The main body includes longitudinal rods 41 and transverse rods 42, both of which are capable of expanding and contracting with the balloon 3. The longitudinal rods 41 extend in the longitudinal direction, and multiple longitudinal rods 41 are spaced apart in the circumferential direction. Transverse rods 42 connect each pair of adjacent longitudinal rods 41, and multiple transverse rods 42 are spaced apart in the longitudinal direction between each pair of adjacent longitudinal rods 41. Thus, a mesh is formed between each pair of adjacent longitudinal rods 41 and each pair of adjacent transverse rods 42.

[0029] Preferably, the connection points of each transverse rod 42 on two adjacent longitudinal rods 41 are located at different positions in the longitudinal direction. In the circumferential direction, the adjacent ends of two adjacent transverse rods 42 are connected, or connected to the same position on the longitudinal rods 41, and the two adjacent transverse rods 42 are symmetrically arranged relative to the longitudinal rods 41 to which they are connected. Thus, after the support 4 expands with the balloon 3, its cross-section is approximately circular, and the mesh openings on the support 4 are arrayed along both the longitudinal and circumferential directions of the support 4. Each transverse rod 42 can have an S-shaped structure, such as... Figure 1 and Figure 2 As shown.

[0030] The diameter and height of the longitudinal rod 41 and the transverse rod 42 are 0.05mm-0.35mm, preferably 0.1mm-0.2mm. The width of the longitudinal rod 41 is 50% wider than the width of the transverse rod 42. In this embodiment, the width of the transverse rod 42 is 0.15mm.

[0031] The connecting part includes a connecting rod 43 extending longitudinally. Multiple connecting rods 43 are spaced apart in the circumferential direction. The end of each connecting rod 41 is connected to or integrally formed with the end of a different longitudinal rod 41. The connecting rod 43 can also expand and contract with the balloon 3.

[0032] In each connecting part, the number of connecting rods 43 is no greater than the number of longitudinal rods 41. In this embodiment, the number of connecting rods 43 in each connecting part is half the number of longitudinal rods 41.

[0033] The connecting rod 43 can have a straight, wavy, or S-shaped structure, with an S-shaped structure being preferred. Figure 1 and Figure 3 As shown, this results in a relatively large deformation of the connecting rod 43 along with the balloon 3.

[0034] The diameter of the connecting rod 43 is 0.05mm-0.35mm, preferably 0.1mm-0.2mm.

[0035] The longitudinal rod 41, the transverse rod 42, and the connecting rod 43 are all made of nickel-titanium material.

[0036] The drug-loaded microsphere layer is disposed on the outer surface of the balloon 3. This layer can be disposed on the entire outer surface of the balloon 3, or it can be distributed at intervals within the areas corresponding to each mesh opening on the outer surface of the balloon 3. In the contracted state, the drug-loaded microsphere layer is located between the balloon 3 and the stent 4. Thus, when the dilator catheter delivers medication into the blood vessel, the stent 4 can separate the blood from the drug-loaded microsphere layer, preventing the blood from washing away the drug-loaded microsphere layer during delivery and thus avoiding loss of the drug-loaded microsphere layer from the outer surface of the balloon. In the expanded state, when part of the balloon 3 protrudes beyond the stent 4 to form a protrusion 31, the drug-loaded microsphere layer located on the protrusion 31 also protrudes beyond the stent 4 and contacts the blood vessel wall, directly squeezing the drug-loaded microsphere layer into the vascular intima, thereby achieving drug delivery. Figure 4 and Figure 5 As shown.

[0037] The drug-loaded microsphere layer includes multiple drug-loaded microspheres 6, which can be spherical, such as... Figure 6 As shown. Alternatively, the drug-loaded microspheres 6 can also be spherical with a pointed tip facing away from the capsule 3, such as... Figure 7 As shown.

[0038] The drug in the drug-loaded microspheres 6 is an anti-inflammatory drug for vascular intimal hyperplasia. Paclitaxel or rapamycin can be used as the drug.

[0039] In this embodiment, the drug-loaded microsphere layer is a biodegradable microsphere layer. The drug-loaded microsphere 6 also includes a drug carrier, which is a biodegradable polymer material, such as PLLA, PGA, PGLA, etc.

[0040] Drug carriers and drugs are combined through blending or physical adsorption to form drug-loaded microspheres 6. Of course, drug-loaded microspheres 6 can also be formed through other processes.

[0041] The drug-loaded microsphere layer also includes excipients, which firmly bind the drug-loaded microspheres 6 to the outer surface of the balloon 3. Amphiphilic excipients are preferred; these are substances that possess both hydrophilic and lipophilic properties. Amphiphilic excipients readily form micelles, which can encapsulate the drug-loaded microspheres 6 during catheter delivery, preventing them from being washed away by blood flow. Upon contact with the vessel wall, the micelles open, allowing the drug-loaded microspheres 6 to migrate into the vessel wall. Examples of suitable excipients include polycaprolactone-polyglycidyl ether and polylactic acid-polyvinylpyrrolidone.

[0042] The thickness of the drug-loaded microsphere layer is 0.06 mm to 0.8 mm. The size of a single drug-loaded microsphere 6 is 200 nm to 100 μm. Specifically, the size of the drug-loaded microsphere 6 is less than 1 μm, or greater than or equal to 1 μm but less than 10 μm, or greater than or equal to 10 μm but less than 100 μm.

[0043] The dilation catheter may also include a protective membrane covering the outside of the stent 4. The protective membrane is made of a biodegradable polymer material and has a thickness of 20 μm. During delivery via the dilation catheter, the protective membrane further reduces drug loss. When the drug-loaded microspheres 6 have pointed tips, the microspheres 6 are more likely to puncture the protective membrane and contact the vessel wall during balloon dilation.

[0044] The inner tube 2 is also provided with contrast rings 7 on both sides of the drug-loaded microsphere particle layer, which can be used to locate the position of the balloon 3 in the blood vessel.

[0045] The method of using this drug-eluting balloon dilation catheter is as follows: (1) When balloon 3 and stent 4 are in a contracted state, balloon 3 and stent 4 are guided to the lesion site in the patient's body. During this process, the drug-loaded microsphere layer is located between balloon 3 and stent 4. (2) A filling medium, which can be gas or liquid, is introduced into the cavity of balloon 3 to expand and maintain the expansion. When balloon 3 expands, it also expands the external stent 4. Since the expansion diameter of balloon 3 is larger than that of stent 4, some parts of balloon 3 bulge out from the mesh of stent 4 to the outside of stent 4, thus forming multiple protrusions 31. The drug-loaded microspheres are located on each protrusion 31, thereby contacting the blood vessel wall and directly squeezing the drug-loaded microspheres into the blood vessel intima. After expansion, balloon 3 widens the narrowed area, increases the blood vessel diameter, and improves blood flow and oxygen supply. (3) After the blood vessels are dilated, the filling medium in the balloon 3 is discharged, causing the balloon 3 and stent 4 to contract, and the stent 4 is withdrawn from the patient's body along with the balloon 3. The above embodiments are only for illustrating the technical concept and features of this utility model. Their purpose is to enable those skilled in the art to understand the content of this utility model and implement it. They should not be used to limit the protection scope of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be covered within the protection scope of this utility model.

Claims

1. A drug-eluting balloon dilation catheter, comprising a balloon, characterized in that: The drug is a drug that inhibits vascular intimal hyperplasia. The drug-eluting balloon dilation catheter also includes a stent covering the outside of the balloon and a drug-loaded microsphere layer disposed on the outer surface of the balloon. Both the balloon and the stent have a contracted state for insertion into the blood vessel and an expanded state for expansion in the blood vessel. In the expanded state, the maximum diameter of the stent is smaller than the maximum diameter of the balloon. The stent has a plurality of spaced meshes along the longitudinal and circumferential directions. In the contracted state, the drug-loaded microsphere layer is housed between the balloon and the stent. In the expanded state, at least a portion of the balloon and the drug-loaded microsphere layer thereon bulge out from each of the mesh openings to the outside of the stent.

2. The drug-eluting balloon dilation catheter according to claim 1, characterized in that: In the expanded state, the mesh openings are arranged in an array along the longitudinal and circumferential directions of the support.

3. The drug-eluting balloon dilation catheter according to claim 1 or 2, characterized in that: The stent includes a main body and connecting portions respectively disposed at both ends of the main body for connection with the balloon. The main body includes longitudinal rods extending in the longitudinal direction, and multiple longitudinal rods are spaced apart in the circumferential direction. The main body also includes transverse rods connected between each pair of adjacent longitudinal rods. Multiple transverse rods are spaced apart in the longitudinal direction between each pair of adjacent longitudinal rods. A mesh is formed between each pair of adjacent longitudinal rods and each pair of adjacent transverse rods. Each longitudinal rod and each transverse rod is capable of expanding and contracting with the balloon.

4. The drug-eluting balloon dilation catheter according to claim 3, characterized in that: The connection points of each of the transverse bars on the two adjacent longitudinal bars are located at different positions in the longitudinal direction.

5. The drug-eluting balloon dilation catheter according to claim 3, characterized in that: Along the circumferential direction, the adjacent ends of two adjacent transverse bars are connected, or connected at the same position on the longitudinal bar.

6. The drug-eluting balloon dilation catheter according to claim 3, characterized in that: The connecting part includes a connecting rod extending in the longitudinal direction. Multiple connecting rods are spaced apart in the circumferential direction. In each connecting part, the number of connecting rods is no greater than the number of longitudinal rods. One end of each connecting rod is connected to or integrally formed with a different longitudinal rod. The connecting rods can expand and contract with the balloon.

7. The drug-eluting balloon dilation catheter according to claim 3, characterized in that: In the contracted state, the area of ​​the mesh openings is less than or equal to 7 mm². 2 In the expanded state, the area of ​​the mesh is 7~25mm. 2 The height of the portion of the balloon protruding outside the stent is 0.02-2 mm.

8. The drug-eluting balloon dilation catheter according to claim 1, characterized in that: The thickness of the drug-loaded microsphere layer is 0.06 mm to 0.8 mm, and the drug-loaded microsphere layer includes multiple drug-loaded microspheres, each of which has a size of 200 nm to 100 μm.

9. The drug-eluting balloon dilation catheter according to claim 8, characterized in that: Each of the drug-loaded microspheres has a size of less than 1 μm, or greater than or equal to 1 μm but less than 10 μm, or greater than or equal to 10 μm but less than 100 μm.

10. The drug-eluting balloon dilation catheter according to claim 1, characterized in that: The drug is either paclitaxel or rapamycin; the drug-loaded microsphere layer is a biodegradable microsphere layer.

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