Drug-loaded balloon catheter

Abstract

The invention provides a medicine-carrying balloon catheter, which relates to the technical field of medical instruments and comprises a balloon body and a conveying catheter, the medicine covering film is arranged on the outer side of the balloon body; the medicine layer is arranged between the medicine covering film and the balloon body; the ejection assembly comprises an inner-layer catheter penetrating through the conveying catheter and extending into the balloon body, an inner-layer balloon arranged on the side wall of the inner-layer catheter and a connecting wire arranged on the outer side wall of the balloon body and connected with the end of the medicine covering film, and the filling medium penetrates through the inner-layer catheter to enable the inner-layer balloon to expand; the medicine covering film, close to the inner-layer sacculus, on the outer side of the sacculus body is broken, and the medicine is released. The inner layer catheter and the conveying catheter which are concentric are arranged, a contrast agent is filled to enable the balloon body to swell out, then the inner layer balloon is ejected out, the connecting wire limits movement of the two ends of the medicine covering film, force is concentrated in the middle of the medicine covering film, and the medicine covering film, close to the inner layer balloon, on the outer side of the balloon body is broken to release medicine.

Description

Technical Field

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

[0002] A balloon catheter is a medical device used in stenotic blood vessel positions. A balloon catheter is inserted into a stenotic or occluded segment, and the balloon is inflated to expand the stenotic or occluded segment so as to make the blood flow in the blood vessel unobstructed. Balloon catheters are mainly used in blood vessels such as coronary arteries, cerebral blood vessels, and large arteries. However, when using a balloon for treatment, the inflated balloon will compress the blood vessel, which may cause blood vessel damage, resulting in excessive proliferation of smooth muscle cells, and it is very likely that restenosis will occur again after a period of time.

[0003] To solve the above problems, the current trend in the prior art is to set drugs, such as paclitaxel, on the surface of the balloon to prevent restenosis at the lesion site. However, during the processes of balloon delivery, dilation, etc., the drug is easily lost under the flushing of blood, and the amount of drug actually reaching the lesion site is small, resulting in a poor preventive effect on restenosis.

[0004] Therefore, an improved technical solution is needed to address the deficiencies of the above - mentioned prior art. Summary of the Invention

[0005] The purpose of the present invention is to provide a drug - loaded balloon catheter. By providing an inner balloon to further push out the balloon body, the drug - coated film is ruptured to release the drug, so as to solve the problems that during the processes of balloon delivery, dilation, etc., the drug is easily lost under the flushing of blood, the amount of drug actually reaching the lesion site is small, and the preventive effect on restenosis is poor.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A drug - loaded balloon catheter, comprising a balloon body and a delivery catheter;

[0008] A drug - coated film provided on the outer side of the balloon body;

[0009] A drug layer provided between the drug - coated film and the balloon body;

[0010] An ejection assembly, the ejection assembly includes an inner catheter passing through the delivery catheter and extending into the interior of the balloon body, an inner balloon provided on the side wall of the inner catheter, a connecting wire provided on the outer side wall of the balloon body and connected to the end position of the drug - coated film, and a filling medium passing through the inner catheter to inflate the inner balloon, causing the drug - coated film near the inner balloon on the outer side of the balloon body to rupture and release the drug.

[0011] Preferably, a guide wire catheter is provided on the inner catheter, and the guide wire catheter is for a guide wire to pass through.

[0012] Preferably, the connecting wires are arranged in a ring shape at equal intervals on the side wall of the inner catheter.

[0013] Preferably, the connecting wires are members made of nitinol alloy wires.

[0014] Preferably, the length of the connecting wires is set such that the balloon body is in a just-straightened or already-straightened state after inflation.

[0015] Preferably, multiple groups of drug coatings are arranged at equal intervals, and the connecting wires, the inner balloon, and the drug coatings are correspondingly arranged.

[0016] Preferably, a Y-shaped valve is connected to the proximal end of the delivery catheter. The middle channel of the Y-shaped valve communicates with the cavity of the inner catheter, and the side channel of the Y-shaped valve communicates with the delivery catheter.

[0017] Preferably, the drug layer is paclitaxel or rapamycin.

[0018] Preferably, a communication port adapted to the inner balloon is provided on the side wall of the inner catheter.

[0019] Preferably, radiopaque rings are provided at both the distal end and the proximal end of the balloon body.

[0020] Advantageous effects:

[0021] (1) By providing concentric inner and delivery catheters, the present invention first fills the gap between the inner and delivery catheters with contrast agent to bulge the balloon body, and then fills the inner catheter with contrast agent to bulge the inner balloon, causing the balloon body to be further pushed out. The connecting wires restrict the movement of both ends of the drug coating, making the force concentrated in the middle of the drug coating, so that the middle of the drug coating ruptures first to release the drug. The drug release is precise, and the drug retention rate is high during the transportation and expansion of the balloon body, thereby improving the preventive effect on restenosis;

[0022] (2) By providing a communication port adapted to the inner balloon on the side wall of the inner catheter, the present invention can effectively ensure the structural strength of the inner catheter and reduce the possibility of deformation of the inner catheter;

[0023] (3) By providing multiple groups of drug coatings, and correspondingly arranging multiple groups of inner balloons and connecting wires, the smaller drug coatings are easier to tear, making the drug coverage of the stenosis uniform. Description of the Drawings

[0024] The accompanying drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0025] Figure 1It is a cross-sectional structural view of the drug-loaded balloon catheter in the embodiment of the present invention;

[0026] Figure 2 It is a cross-sectional structural view of the overall structure of the drug-loaded balloon catheter in the contracted state in the embodiment of the present invention;

[0027] Figure 3 It is Figure 2 an enlarged view of the structure at position A of

[0028] Figure 4 It is a cross-sectional structural view of the overall structure of the drug-loaded balloon catheter in the inflated state in the embodiment of the present invention;

[0029] Figure 5 It is Figure 4 an enlarged view of the structure at position B of

[0030] In the figure: 1. Balloon body; 2. Delivery catheter; 3. Drug coating film; 4. Drug layer; 51. Inner catheter; 511. Communication port; 52. Inner balloon; 53. Connecting wire; 54. Guide wire catheter; 6. Y-shaped valve; 7. Marking ring. Detailed implementation manners

[0031] Next, the technical solutions in the embodiments of the present invention will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art belong to the scope protected by the present invention.

[0032] In the description of the present invention, it should be understood that for the orientation description, such as the upper, lower, front, rear, left, right, etc., the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0033] In the description of the present invention, the meaning of several is one or more, the meaning of multiple is two or more, greater than, less than, exceeding, etc. are understood as not including the present number, and above, below, within, etc. are understood as including the present number. If there is a description of first and second, it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0034] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features.

[0035] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the term "connection" should be understood in a broad sense. For example, it can be a fixed connection or a movable connection, or a detachable connection or a non-detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection or a connection capable of mutual communication; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two components, indirect communication or the interaction relationship between two components.

[0036] In the description of the present invention, "distal end" refers to the end farther from the doctor during the operation, and "proximal end" refers to the end closer to the doctor during the operation.

[0037] In the description of the present invention, "before use" refers to the state before the drug-coated balloon catheter is not used, not inserted into the human body or not in contact with body fluids such as blood and tissue fluid in the human body, and "during use" refers to the state after the drug-coated balloon catheter has been inserted into the human body or in contact with body fluids such as blood and tissue fluid in the human body.

[0038] In the description of the present invention, the "contracted state" refers to the state in which the "balloon body" fits together within a partial length range or the entire length range.

[0039] In the description of the present invention, the "in-vivo environment" refers to the environment below the epidermis of the skin where body fluids exist, such as the dermis layer and subcutaneous tissue, or inside blood vessels, organs, etc.

[0040] The present invention will be described in detail below with reference to embodiments. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0041] In the prior art, when drugs are provided on the surface of the balloon, during the transportation and expansion of the balloon, the drugs are easily lost under the flushing of blood, and the amount of drugs actually reaching the lesion site is small, resulting in a poor prevention effect on restenosis.

[0042] The present invention provides a drug-coated balloon catheter, referring to Figures 1 to 5 , including a balloon body 1 and a delivery catheter 2;

[0043] A drug film 3 provided on the outer side of the balloon body 1;

[0044] A drug layer 4 provided between the drug film 3 and the balloon body 1;

[0045] Ejection assembly. The ejection assembly includes an inner catheter 51 that passes through the delivery catheter 2 and extends into the interior of the balloon body 1, an inner balloon 52 provided on the side wall of the inner catheter 51, and a connecting wire 53 provided on the outer side wall of the balloon body 1 and connected to the end position of the drug coating film 3. Specifically, the position where the connecting wire 53 is connected to the drug coating film 3 is set at a distance of 1 mm from the end of the drug coating film 3. The purpose is to enable the connecting wire 53 to directly pull the drug coating film 3 after being straightened. Contrast agent or gas passes through the inner catheter 51 to expand the inner balloon 52, causing the drug coating film 3 near the inner balloon 52 on the outside of the balloon body 1 to rupture and release the drug.

[0046] Specifically, contrast agent is filled into the gap between the inner catheter 51 and the delivery catheter 2 to bulge the balloon body 1. Then, contrast agent is filled into the inner catheter 51 to bulge the inner balloon 52, causing the balloon body 1 to be further ejected. The connecting wire 53 restricts the movement of both ends of the drug coating film 3.

[0047] The balloon body 1 is an expandable sac-like structure made of nylon or PET and expands into an oval sphere after being filled with a filling medium. The balloon body 1 has certain flexibility and biocompatibility, has good passage in blood vessels and has little impact on the internal environment of the body.

[0048] The delivery catheter 2 is connected to the balloon body 1 by bonding or welding. The delivery catheter 2 is provided with a channel that runs through its own length direction, and liquid or gas can enter the balloon body 1 from the channel.

[0049] The drug coating film 3 is fixed on the balloon body 1 by bonding. The drug coating film 3 is a component made of polylactic acid material. The drug coating film 3 has certain ductility and can remain attached while the balloon body 1 expands. After the balloon body 1 expands, the drug coating film 3 is in a near-limit stretching state.

[0050] The inner catheter 51 is a tube body made of PET material, has certain structural strength, and has a cavity provided along its length direction. The cavity does not penetrate the inner catheter 51 at the distal end. The inner catheter 51 is not easily deformed under the influence of the internal pressure of the balloon body 1. The inner balloon 52 is made of PU material and has certain expansion and contraction properties. During operation, a filling medium can be injected along the inner catheter 51 to compress and expand the inner balloon 52. The position of the inner balloon 52 corresponds to the position of the drug coating film 3. After the inner balloon 52 expands, it abuts against the inner side wall of the balloon body 1.

[0051] Specifically, the filling medium can be liquid or gas, such as contrast agent, normal saline, helium gas, and iodine contrast agent is preferably used.

[0052] The connecting wire 53 is a component made of a material with certain elasticity, preferably a nitinol wire. One end of the connecting wire 53 is welded or bonded to the outer side wall of the balloon body 1, and the other end is welded or heat-melted to the end of the drug coating film 3. After the inner balloon 52 expands, a radially outward pressure is applied to the balloon body 1, causing the drug coating film 3 to be deformed under pressure. At this time, the connecting wire 53 is in a straightened state, and both ends of the drug coating film 3 are connected to the connecting wire 53, and the deformation amount is limited. As a result, the middle part of the drug coating film 3 first ruptures after being subjected to a certain pressure, enabling the internal drug layer 4 to adhere to the inner wall of the blood vessel. By setting the inner catheter 51 to control the ejection of the inner balloon 52, the connecting wire 53 restricts the movement of both ends of the drug coating film 3, allowing the middle part to first rupture and release the drug. The drug release is precise, and the drug preservation rate is high during the transportation and expansion of the balloon body 1, thereby enhancing the preventive effect against restenosis.

[0053] During use, first, a filling medium is filled into the delivery catheter 2 to expand the balloon body 1. Then, a filling medium is delivered into the inner catheter 51. After the inner balloon 52 expands, it abuts against the side wall of the balloon body 1, and the connecting wire 53 applies a pulling force to the drug coating film 3. During the process of the drug coating film 3 expanding under the extrusion force of the inner balloon 52, the force is concentrated in the middle part and first ruptures, enabling the drug protected by the drug coating film 3 to be released. The released drug directly adheres to the lesion site, playing a good role in preventing restenosis.

[0054] In a preferred embodiment of the present invention, a guide wire catheter 54 is provided on the inner catheter 51, and the guide wire catheter 54 allows the guide wire to pass through. By providing the guide wire catheter 54, it is easy for the guide wire to reach the position, and thus it is convenient for the balloon to reach the position.

[0055] In a preferred embodiment of the present invention, the inner balloon 52 is located between the connecting wires 53. By arranging the inner balloon 52 between the connecting wires 53, after the inner balloon 52 expands, it can abut against the corresponding position of the drug coating film 3, ensuring the stability of drug release.

[0056] In a preferred embodiment of the present invention, the connecting wires 53 are arranged in an annular and equally spaced manner on the outer side wall of the balloon body 1. In one embodiment, the connecting wires 53 are arranged in six, and the ends of the drug coating film 3 can be stably connected. In other embodiments, in order to make the ends of the drug coating film 3 more stable, the connecting wires 53 can be arranged in 7, 8, 9 or more numbers.

[0057] In a preferred embodiment of the present invention, the connecting wire 53 is a component made of nitinol wire. The nitinol wire has a certain structural strength and elasticity, and can stably hold both ends of the drug coating film 3 after being straightened, improving the stability of the connecting wire 53. In other embodiments of the present application, the connecting wire 53 can be a component made of nylon, enabling the connecting wire 53 to have a certain structural strength and stably connecting the drug coating film 3.

[0058] In a preferred embodiment of the present invention, the length of the connecting wire 53 is set such that the balloon body 1 is in a just-straightened or already-straightened state after inflation. Specifically, in the contracted state, the connecting wire 53, the balloon body 1, and the inner balloon 52 are all in the contracted state. In the inflated state, the balloon body 1 expands and straightens the connecting wire 53. At this time, the connecting wire 53 generates a pulling force on the drug coating 3.

[0059] In a preferred embodiment of the present invention, multiple groups of drug coatings 3 are arranged at equal intervals, and the connecting wire 53, the inner balloon 52, and the drug coating 3 are arranged correspondingly. By arranging multiple groups of drug coatings 3, a single drug coating 3 can be made smaller, thereby facilitating the tearing of the drug coating 3. Moreover, the design of multiple groups of drug coatings 3 allows the release points of the drug layer 4 to be uniform, enabling the drug to be released more evenly and improving the accuracy of drug release.

[0060] In a specific embodiment, the drug coating 3 is arranged in two groups, and each group of drug coatings 3 is connected to each other. Connecting wires 53 are connected to both ends of each group of drug coatings 3, and the inner balloon 52 is arranged between the corresponding connecting wires 53, with the quantity and position corresponding to those of the drug coating 3. According to the different lengths of the stenosis, the drug coating 3 can be arranged in three groups, four groups, five groups, or six groups.

[0061] In a preferred embodiment of the present invention, a Y-valve 6 is connected to the proximal end of the delivery catheter 2. The main channel of the Y-valve 6 is communicated with the cavity of the inner catheter 51, and the side channel of the Y-valve 6 is communicated with the delivery catheter 2. The Y-valve 6 and the proximal end of the delivery catheter 2 are fixed by means of a Luer connection. The Luer connection is a medical connection system that enables the safe and leak-free connection between the proximal end of the delivery catheter 2 and the Y-valve 6, allowing the filling medium to be stably delivered through the Y-valve 6.

[0062] In a preferred embodiment of the present invention, the drug layer 4 is paclitaxel or sirolimus. When paclitaxel and sirolimus are released onto the blood vessel wall, they can inhibit the proliferation of vascular smooth muscle cells, thereby effectively preventing vascular restenosis.

[0063] In a preferred embodiment of the present invention, a communication port 511 adapted to the inner balloon 52 is provided on the side wall of the inner catheter 51. Only one communication port 511 is designed on the side wall of the inner catheter 51 to avoid the influence of multiple communication ports 511 on the structural strength of the inner catheter 51 and reduce the possibility of deformation of the inner catheter 51.

[0064] In a preferred embodiment of the present invention, radiopaque rings 7 are provided at both the distal and proximal ends of the balloon body 1. The radiopaque rings 7 are fixed to the balloon body 1 by means of adhesion. The radiopaque rings 7 are made of platinum-iridium alloy, which can assist the doctor in judging the position of the balloon body 1 under imaging equipment and reduce the surgical difficulty. Both the distal and proximal ends of the balloon body 1 are designed with a constriction, and the constricted parts are connected to the radiopaque rings 7.

[0065] In a preferred embodiment of the present invention, the distal diameter of the balloon body 1 gradually contracts from the proximal end to the distal end, and the diameter of the proximal end of the balloon body 1 gradually expands from the proximal end to the distal end. Hydrogel coatings are provided at both of the above two positions. By generating a water film on the balloon body 1, the surface friction of the balloon body 1 is reduced, thereby facilitating the delivery and retrieval of the balloon body 1.

[0066] The following specifically describes a drug - loaded balloon catheter of the present invention through specific embodiments.

[0067] Embodiment 1

[0068] This embodiment provides a drug - loaded balloon catheter. Referring to Figures 1 to 5 , it includes a delivery catheter 2. The delivery catheter 2 has a channel running through its own length direction. The inner catheter 51 passes through the channel of the delivery catheter 2, and the delivery catheter 2 and the inner catheter 51 are concentrically arranged. The proximal ends of the delivery catheter 2 and the inner catheter 51 are commonly connected with a Y - valve 6 in a luer connection manner. Among them, the main channel of the Y - valve 6 communicates with the cavity of the inner catheter 51, and the side channel of the Y - valve 6 communicates with the delivery catheter 2. By setting the Y - valve 6, the input between the delivery catheter 2 and the inner catheter 51 is not interfered with each other, reducing the difficulty of inputting the filling medium.

[0069] The distal end of the delivery catheter 2 is welded with a balloon body 1. The balloon body 1 is an expandable sac - like structure made of PET material, having a certain expansion and contraction ability. When the position of the balloon body 1 needs to be adjusted multiple times, it can meet multiple expansions and contractions and is not easily damaged. At the same time, PET has less impact on the internal environment of blood vessels. The distal and proximal diameters of the balloon body 1 both gradually contract from the middle to the ends to form contraction segments, and the contraction segments are provided with hydrogel coatings to reduce the surface friction of the balloon body 1, thereby improving the passability of the balloon body 1. The filling medium can enter the balloon body 1 along the gap between the delivery catheter 2 and the inner catheter 51. After the balloon body 1 is filled, it expands, and after the filling medium is withdrawn, the balloon body 1 contracts.

[0070] A drug - coated film 3 is adhered to the outer surface of the balloon body 1. The drug - coated film 3 is a component made of polylactic acid material. The drug - coated film 3 has a certain ductility and can remain attached while the balloon body 1 expands. After the balloon body 1 expands, the drug - coated film 3 is in a near - limit stretching state.

[0071] The inner catheter 51 is a tube body made of PET material, having a certain structural strength, and a cavity is arranged along the length direction inside. The cavity does not penetrate the inner catheter 51 at the distal end.

[0072] The distal side wall of the inner catheter 51 is adhesively bonded with an inner balloon 52, and the inner balloon 52 is a component made of PU and has a certain expandability and contractibility. During operation, a filling medium can be injected along the inner catheter 51 to make the inner balloon 52 expand after being filled. The position of the inner balloon 52 corresponds to the position of the drug coating film 3. After the inner balloon 52 expands, it abuts against the inner side wall of the balloon body 1, and the inner side wall of the balloon body 1 is squeezed to make the drug coating film 3 stressed.

[0073] The filling medium includes but is not limited to contrast agents, helium, and normal saline. Preferably, an iodine contrast agent is used. Under a imaging device, the filling medium can be visualized, which is convenient for doctors to judge.

[0074] A guide wire catheter 54 is melt-connected to the inner catheter 51. The guide wire catheter 54 penetrates axially for a guide wire to pass through. After the guide wire passes through, it guides the balloon body 1 to facilitate its placement.

[0075] A connecting wire 53 is welded to the outer side wall of the balloon body 1. The other end of the connecting wire 53 is fusion-bonded to the drug coating film 3. A certain distance is set between the connection part of the connecting wire 53 and the drug coating film 3 and the end of the drug coating film 3. The purpose is that after the balloon body 1 expands, the connecting wire 53 straightens and pulls the end of the drug coating film 3. The connecting wire 53 is preferably made of nitinol wire or can also be made of nylon material. The connecting wire 53 has a certain elasticity and structural strength. After the inner balloon 52 expands, the inner balloon 52 exerts a radially outward pressure on the balloon body 1, making the drug coating film 3 deformed under pressure. The two ends of the drug coating film 3 are connected to the connecting wire 53, and the amount of deformation is limited. As a result, the middle part of the drug coating film 3 first ruptures after being subjected to a certain pressure, so that the internal drug layer 4 adheres to the inner wall of the blood vessel. By setting the inner catheter 51 to control the protrusion of the inner balloon 52 and the connecting wire 53 to limit the movement of the two ends of the drug coating film 3, the middle part first ruptures to release the drug, the drug release is precise, and the drug retention rate is high during the transportation and expansion of the balloon body 1, thereby improving the preventive effect on restenosis.

[0076] During use, after the balloon body 1 is in place, a contrast agent is injected into the side channel of the Y-valve 6. The contrast agent fills the balloon body 1 and makes the balloon body 1 expand, and the drug coating film 3 also expands and adheres more closely to the side wall of the balloon body 1; a contrast agent is input into the main channel of the Y-valve 6. After the inner balloon 52 is filled, it gradually expands and at least expands radially and abuts against the side wall of the balloon body 1. At this time, the balloon body 1 is further pushed out, and both ends of the drug coating film 3 are pulled by the connecting wire 53, and the expansion is restricted, so that the force is concentrated in the middle part of the drug coating film 3, making the drug coating film 3 tear first, thereby realizing the release of the drug. The drug adheres to the blood vessel wall after being released from the drug coating film 3. The drug layer 4 is preferably made of paclitaxel or rapamycin. When the drug layer 4 is released onto the blood vessel wall, it can inhibit the proliferation of vascular smooth muscle cells, thereby effectively preventing vascular restenosis.

[0077] In this embodiment, a communication port 511 adapted to the inner balloon 52 is provided on the side wall of the inner catheter 51. Only one communication port 511 is designed on the side wall of the inner catheter 51 to avoid the design of multiple communication ports 511 affecting the structural strength of the inner catheter 51 and reducing the possibility of deformation of the inner catheter 51.

[0078] In this embodiment, a developer ring 7 is bonded to the end of the contraction section of the balloon body 1. The developer ring 7 is made of platinum-iridium alloy, which can assist the doctor in judging the position of the balloon body 1 under the imaging device and reduce the surgical difficulty.

[0079] In this embodiment, the connecting wires 53 are welded to the side wall of the inner catheter 51 at equal intervals in a circular shape. Six connecting wires 53 are provided, which can stably connect the ends of the drug film 3.

[0080] In other embodiments of the present invention, in order to make the ends of the drug film 3 more stable, the number of connecting wires 53 can be set to 7, 8, 9 or more.

[0081] Embodiment 2

[0082] Refer to Figure 4 , the difference between this embodiment and the first embodiment is that the number of drug films 3 is different. In order to make the drug film 3 easier to tear, the drug film 3 can be set in a form of small area and multiple groups. The drug film 3 with a small area is more sensitive to the deformation amount of the balloon body 1 and is easier to tear and release the drug when the balloon body 1 deforms. In this embodiment, the drug film 3 is set in two groups, and each group of drug films 3 is connected to each other. The advantage of this design is that the drug film 3 can be seamlessly connected to ensure uniform coverage of the blood vessel wall at the stenosis.

[0083] Specifically, according to the different lengths of the stenosis, the drug film 3 is set in three groups, four groups, five groups, or six groups.

[0084] In summary: By providing the concentric inner catheter 51 and the delivery catheter 2, the balloon body 1 bulges by filling with contrast agent, and then the inner balloon 52 is pushed out, and the balloon body 1 is further pushed out. The connecting wires 53 limit the movement of both ends of the drug film 3, so that the force is concentrated in the middle of the drug film 3, causing the drug film 3 on the outer side of the balloon body 1 near the inner balloon 52 to rupture and release the drug. The drug release is accurate, and the drug preservation rate is high during the transportation and expansion of the balloon body 1, thereby improving the preventive effect on restenosis.

[0085] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A drug-loaded balloon catheter, characterized in that: It includes a balloon body and a delivery catheter; A drug coating disposed on the outside of the balloon body; A drug layer disposed between the drug coating and the balloon body; The ejection assembly includes an inner layer catheter passing through the delivery catheter and extending to the inside of the balloon body, an inner layer balloon arranged on the side wall of the inner layer catheter, and a connecting wire arranged on the outer side wall of the balloon body and connected to the end position of the drug coating. The filling medium passes through the inner layer catheter to expand the inner layer balloon, causing the drug coating on the outside of the balloon body close to the inner layer balloon to rupture and release the drug.

2. The drug-loaded balloon catheter according to claim 1, characterized in that: The inner layer catheter is provided with a guidewire catheter, and the guidewire catheter is used for the guidewire to pass through.

3. The drug-loaded balloon catheter according to claim 1, characterized in that: The connecting wires are arranged in a ring shape and at equal intervals on the side wall of the inner layer conduit.

4. The drug-loaded balloon catheter according to claim 1, characterized in that: The connecting wire is a component made of nickel-titanium alloy wire.

5. The drug-loaded balloon catheter according to claim 4, characterized in that: The length of the connecting wire is set to allow the balloon body to be in a just straightened or straightened state after expansion.

6. The drug-loaded balloon catheter according to claim 1, characterized in that: The drug coatings are arranged in multiple groups at equal intervals, and the connecting wires, the inner balloon and the drug coatings are arranged correspondingly.

7. The drug-loaded balloon catheter according to claim 1, characterized in that: The proximal end of the delivery catheter is connected with a Y-shaped valve, the main channel of the Y-shaped valve is communicated with the cavity of the inner layer catheter, and the side channel of the Y-shaped valve is communicated with the delivery catheter.

8. A drug-loaded balloon catheter according to any one of claims 1 to 7, characterized in that: The drug layer is paclitaxel or rapamycin.

9. A drug-loaded balloon catheter according to any one of claims 1 to 7, characterized in that: A communication port matched with the inner layer balloon is provided on the side wall of the inner layer catheter.

10. A drug-loaded balloon catheter according to any one of claims 1 to 7, characterized in that: The distal end and the proximal end of the balloon body are both provided with developing rings.

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