Intracranial controllable drug balloon dilatation catheter and drug delivery method for narrow area of blood vessel

Abstract

The invention relates to the technical field of manufacturing of medical instruments, in particular to an intracranial controllable drug balloon dilatation catheter and a drug delivery method for a narrow area of a blood vessel. According to the intracranial controllable medicine balloon dilatation catheter, the inner-layer catheter body is arranged in the outer-layer catheter body in a sleeved mode and fixedly connected with the far end of the outer-layer catheter body; the balloon is assembled on the outer-layer tube body and is provided with a plurality of dosing holes along the circumferential direction; a medicine adhesion layer is compounded on the surface of the balloon section of the outer-layer tube body; the stress releasing pipe is connected to the end, close to the operation end, of the outer-layer pipe body. The Y-shaped tube base is connected to the end, away from the outer-layer tube body, of the stress releasing tube, one connector is connected with an injection device to inject medicine carriers into the balloon, and the other connector is used for a guide wire to penetrate through. When intracranial vascular stenosis is treated, directional drug release can be achieved by means of the drug delivery holes and the drug adhesion layer. The medicine is sprayed to the focus through the administration hole, the medicine is promoted to permeate into the middle layer of the blood vessel wall through the attaching force generated by the balloon expansion, the problems of non-uniform liquid medicine distribution, insufficient permeation and the like are effectively solved, and the local medicine concentration and the treatment effect are improved.

Description

Technical Field

[0001] This invention relates to the field of medical device manufacturing technology, and in particular to an intracranial controllable drug balloon dilation catheter and a method for drug delivery to vascular stenosis areas. Background Technology

[0002] Intracranial vascular stenosis is a major cause of ischemic stroke, seriously threatening patients' lives and health. Currently, commonly used clinical treatments include conservative drug therapy, endovascular interventional therapy, and balloon angioplasty. Among these, balloon angioplasty is widely used due to its minimally invasive nature and relatively simple procedure.

[0003] Intracranial balloon dilation catheters are mainly used to mechanically dilate narrowed blood vessels and restore blood flow, but the restenosis rate is high after the procedure. To address this issue, drug-eluting balloon technology has emerged. This technology uses an anti-proliferative drug carried on the surface of the balloon, which is released to the vessel wall during dilation to inhibit excessive smooth muscle cell proliferation and reduce the risk of restenosis.

[0004] However, existing drug-eluting balloon catheters have several shortcomings in intracranial applications: First, drug release efficiency is low, relying heavily on mechanical compression during balloon expansion to achieve drug transfer, making it difficult to precisely control the dosage and range of administration; second, the uniformity of balloon-vascular wall adhesion is insufficient, leading to uneven drug distribution and affecting treatment efficacy; third, it is difficult to balance catheter delivery and tracking performance, as intracranial vessels are tortuous and small, requiring catheters to have both good support and flexibility, which existing products often fail to meet; fourth, the interaction between the drug carrier and the vessel wall lacks effective regulation, resulting in insufficient drug penetration depth and the inability to form an effective drug concentration in the middle layer of the vessel wall.

[0005] In summary, technical personnel are urgently needed to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide an intracranial controllable drug-eluting balloon dilation catheter, which aims to solve the problems of low drug release efficiency, insufficient drug delivery accuracy, uneven drug distribution due to poor uniformity of balloon-to-vascular wall adhesion, and insufficient drug carrier penetration depth in the intracranial application of existing drug-eluting balloon catheters.

[0007] This invention relates to an intracranial controllable drug-eluting balloon dilation catheter, characterized in that it comprises an inner tube body, an outer tube body, a balloon, a stress-relieving tube, and a Y-shaped connector; the inner tube body is sleeved within the outer tube body and fixedly connected to the distal end of the outer tube body; the balloon is assembled on the outer tube body and has multiple drug delivery ports along its circumference; the surface of the balloon section of the outer tube body is coated with a drug adhesion layer; the stress-relieving tube is connected to the end of the outer tube body near the operating end; the Y-shaped connector is connected to the end of the stress-relieving tube away from the outer tube body, and one interface of the Y-shaped connector is used to connect an injection device to inject a drug carrier into the balloon, and the other interface is used for guidewire insertion.

[0008] As a further improvement to the technical solution disclosed in this invention, the balloon is formed with multiple grooves, which are evenly distributed circumferentially along its central axis; the drug delivery holes are evenly distributed in each groove.

[0009] As a further improvement to the technical solution disclosed in this invention, the inner tube is composed of a low-friction lubrication layer, a support and reinforcement layer, and a flexible adaptation layer in the radial direction.

[0010] As a further improvement to the technical solution disclosed in this invention, the low-friction lubrication layer is made of polytetrafluoroethylene or polyethylene; the support reinforcement layer is a spring body, a braided structure or a metal hyaluronic acid tube; the flexible adapter layer is made of Nylon12, Pebax or TPU, and has a gradual change in hardness from the proximal end to the distal end.

[0011] As a further improvement to the technical solution disclosed in this invention, along its radial direction, the outer tube is composed of a support layer and a polymer material layer with gradually varying hardness, sequentially from the inside to the outside.

[0012] As a further improvement to the technical solution disclosed in this invention, corresponding to the assembly position of the balloon, multiple drug carrier filling holes are evenly distributed circumferentially on the outer tube.

[0013] As a further improvement to the technical solution disclosed in this invention, a imaging ring is provided at the distal end of the outer tube body, next to the drug carrier filling hole.

[0014] Furthermore, this invention also discloses a method for drug delivery to areas of vascular stenosis, implemented using an intracranial controllable drug balloon dilation catheter, comprising the following steps: S1: Preoperative preparation and catheter delivery The guidewire is inserted through the instrument interface of the Y-shaped tube and then through the lumen of the inner tube until the distal end of the guidewire crosses the stenotic area of ​​the intracranial blood vessel. The balloon is then pushed to the stenotic area along the extension trajectory of the guidewire, and the alignment accuracy between the balloon and the stenotic area is confirmed with the assistance of imaging equipment. S2: Balloon pre-dilation and drug delivery injection The injection device is connected to the injection device interface of the Y-shaped tube seat. The expansion medium is slowly injected into the balloon to inflate the balloon to the preset pressure and pre-dilate the narrowed blood vessel wall. After the pre-dilation is completed, the balloon is kept in an inflated state, and a drug carrier solution containing paclitaxel or rapamycin is injected through the same injection interface until the drug carrier fills the internal cavity of the balloon and the drug concentration matches the drug loading of the drug adhesion layer. S3: Targeted drug release and penetration Maintaining the balloon's inflation pressure, the drug carrier is evenly sprayed onto the surface of the blood vessel wall in the narrowed area through the drug delivery port; at the same time, the adhesion force of the balloon to the blood vessel wall after inflation promotes the penetration of the drug carrier into the middle layer of the blood vessel wall. S4: Balloon decompression and catheter withdrawal The residual drug carrier and expansion medium inside the balloon are slowly released through the injection device. After the balloon is fully contracted, the intracranial controllable drug balloon dilation catheter is slowly withdrawn in the opposite direction along the guidewire. The guidewire is left in the blood vessel for observation. After imaging equipment confirms that there is no thrombus formation in the stenotic area and that blood flow in the blood vessel is unobstructed, the guidewire is then slowly withdrawn.

[0015] As a further improvement to the technical solution disclosed in this invention, in step S2, the expansion medium is physiological saline or iopromide, and when the expansion medium is injected into the balloon, a slow and uniform injection method is adopted.

[0016] As a further improvement to the technical solution disclosed in this invention, in step S3, during the process of the drug carrier being sprayed onto the surface of the blood vessel wall through the drug delivery orifice, the balloon inflation pressure is kept stable; and after the drug carrier has finished spraying, the balloon is kept in contact with the blood vessel wall for a preset time.

[0017] Regarding the topic of intracranial controllable drug-eluting balloon dilation catheters, their practical application can achieve at least the following beneficial technical effects, specifically: 1) Multiple drug delivery ports circumferentially arranged on the balloon, combined with a drug adhesion layer on the surface of the outer tube, enable targeted release and dual action of the drug carrier. During surgery, the drug is directly sprayed through the delivery ports, and the adhesion force after the balloon expands promotes drug penetration into the middle layer of the blood vessel wall, thus effectively solving the problems of uneven distribution and insufficient penetration of traditional drug delivery balloons, and improving local drug concentration and efficacy. 2) The nested fixed connection between the inner and outer tubes, along with the stress relief tube, ensures the overall rigidity and tracking of the intracranial controllable drug balloon dilation catheter, while also adapting to the anatomical characteristics of tortuous intracranial blood vessels. Furthermore, the dual-interface design of the Y-shaped tube seat enables independent operation of drug injection and guidewire insertion, simplifying the surgical procedure, improving intraoperative controllability, and better meeting the precision operation requirements of intracranial interventional therapy.

[0018] Regarding the topic of drug delivery methods in areas of vascular stenosis, its practical application yields at least the following beneficial technical effects: During the surgical procedure, guidewire positioning and precise balloon alignment are first achieved. Pre-dilation creates suitable conditions for drug penetration, followed by drug carrier release under stable expansion pressure. The drug evenly covers the vessel wall surface through the delivery port and, with the help of the balloon's adhesion to the vessel wall, penetrates into the middle layer, forming a synergistic effect between the surface and deep layers. This effectively improves the problems of uneven drug distribution and limited depth of action in traditional methods, ensuring that the local drug concentration meets therapeutic requirements. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a three-dimensional schematic diagram of the intracranial controllable drug balloon dilation catheter disclosed in this invention.

[0021] Figure 2 yes Figure 1 Top view.

[0022] Figure 3 yes Figure 2 AA sectional view.

[0023] Figure 4 yes Figure 3 A magnified view of part of I.

[0024] Figure 5 yes Figure 3 A magnified view of part II.

[0025] Figure 6 This is a three-dimensional schematic diagram of the inner tube of the intracranial controllable drug balloon dilation catheter disclosed in this invention.

[0026] Figure 7 This is a three-dimensional schematic diagram of the outer tube of the intracranial controllable drug balloon dilation catheter disclosed in this invention.

[0027] Figure 8 This is a three-dimensional schematic diagram of the balloon in the intracranial controllable drug balloon dilation catheter disclosed in this invention.

[0028] 1-Inner tube body; 2-Outer tube body; 21-Drug carrier filling hole; 3-Balloon; 31-Groove; 32-Drug administration port; 4-Stress relief tube; 5-Y-type tube seat; 51-Drug injection interface; 52-Device interface. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to specific embodiments. Figures 1-5 The diagram shows the structure of the intracranial controllable drug-eluting balloon dilation catheter disclosed in this invention. It can be seen that it mainly consists of an inner tube body 1 (such as...). Figure 6 As shown), outer tube 2 (as shown) Figure 7 As shown), balloon 3 (as shown) Figure 8 The device is composed of several parts, including the inner tube 1 (shown in the diagram), the stress relief tube 4, and the Y-shaped tube seat 5. The inner tube 1 is fitted inside the outer tube 2 and is fixedly connected only to the distal end of the outer tube 2. The balloon 3 is mounted at a pre-set position on the outer tube 2, serving as the core carrier for vasodilation and drug release. The stress relief tube 4 is connected to the end of the outer tube 2 closest to the operating end to buffer stress concentration during the procedure. The Y-shaped tube seat 5 is connected to the end of the stress relief tube 4 furthest from the outer tube 2, enabling independent drug injection and guidewire insertion, thus meeting the overall treatment needs for intracranial arterial atherosclerosis.

[0030] The inner tube 1 preferably adopts a radial three-layer composite structure, consisting of a low-friction lubrication layer, a support and reinforcement layer, and a flexible adaptation layer from the inside out. The low-friction lubrication layer is precision-machined to form a smooth inner wall surface, reducing frictional resistance during guidewire or auxiliary instrument insertion. The low-friction lubrication layer is made of polytetrafluoroethylene (PTFE) or polyethylene to ensure smooth guidewire movement within the tube and prevent excessive frictional resistance from affecting the doctor's operational precision.

[0031] It is worth noting that the supporting reinforcement layer uses a spring body, a braided structure, or a metal hypotube. If a braided structure is chosen, the number of spindles is controlled within the range of 16 to 36. In this way, not only is sufficient pushing rigidity provided to the inner tube 1 to ensure that it effectively transmits pushing force in intracranial blood vessels, but it also retains a certain degree of flexibility to prevent the tube from bending in tortuous blood vessels, laying the foundation for subsequent precise location of lesions.

[0032] The flexible adapter layer plays a crucial role in adapting to the anatomical features of intracranial blood vessels and is made of Nylon 12, Pebax, or TPU. The flexible adapter layer exhibits a gradual change in hardness from proximal to distal. This allows the proximal end of the inner tube body 1 to have higher rigidity, facilitating the application of pushing force and torque by the physician and improving operational control; while the distal end maintains its softness, allowing it to flexibly deform along the curvature of the intracranial blood vessels, reducing friction and damage to the vessel walls, and ensuring the catheter successfully reaches the lesion area.

[0033] The outer tube 2 preferably adopts a radial two-layer composite structure, consisting of a support layer and a layer of polymer material with gradually varying hardness from the inside out. The support layer uses a spring-like or braided structure, which works in conjunction with the support and reinforcement layer of the inner tube 1 to further improve the anti-torsion performance of the intracranial controllable drug balloon dilation catheter, ensuring that the doctor's torsional manipulation can be accurately transmitted to the distal end, achieving rapid positioning of the balloon 3. The polymer material layer with gradually varying hardness is made of Nylon12, Pebax, or TPU, and has 2 to 5 hardness gradients along the length of the tube. Its distal hardness matches the distal hardness of the flexible adaptation layer of the inner tube 1, while its proximal hardness is slightly higher than that of the proximal end of the inner tube 1, forming a "synergistic hardness gradient between the inner and outer layers," which ensures both delivery stability and enhances vascular compatibility.

[0034] Corresponding to the assembly position of the balloon 3, the outer tube 2 has multiple drug carrier filling holes 21 evenly distributed along the circumference, and the holes are elliptical in shape (e.g., Figure 7 As shown in the figure, the drug carrier filling hole 21 is connected to the internal cavity of the balloon 3. After the drug carrier enters the balloon 2 through the drug carrier filling hole 21, it is then evenly sprayed onto the surface of the blood vessel wall in the narrowed area through the drug delivery hole 32. Furthermore, a contrast ring (not shown in the figure) is provided at the distal end of the outer tube 2, next to the drug carrier filling hole 21, and the contrast ring is made of platinum-iridium alloy or platinum-tungsten alloy. The position of the balloon 3 can be clearly shown under X-ray fluoroscopy, helping doctors to accurately determine the alignment of the balloon 3 with the lesion area and avoid the balloon 3 deviating from the treatment site.

[0035] As Figure 8 As shown, the balloon 3 is formed with multiple grooves 31, which are evenly distributed circumferentially along its central axis. Drug delivery orifices 32 are evenly distributed within each groove 31. When the balloon 3 inflates, the grooves 31 prevent the drug delivery orifices 32 from directly contacting the blood vessel wall, thus preventing the drug delivery orifices 32 from scratching the blood vessel wall.

[0036] In addition, the balloon segment of the outer tube 2 is coated with a drug adhesion layer (not shown in the figure). The drug adhesion layer is made of a special polyurethane material. Drugs such as paclitaxel or rapamycin are uniformly adhered to the surface of the drug adhesion layer in powder form. This effectively avoids drug loss due to folding and friction during delivery, ensuring that the drug remains in sufficient quantity before reaching the lesion area, thus providing a guarantee for subsequent effective treatment.

[0037] Furthermore, the stress relief tube 4 is preferably made of soft Pebax material, with its inner diameter matching the outer diameter of the outer tube 2, and is fixedly connected to the end of the outer tube 2 near the operating end. When the doctor applies pushing force or torque at the operating end, the stress relief tube 4 can buffer stress concentration through its own deformation, preventing the outer tube 2 from breaking due to excessive stress, while also improving the doctor's operating feel and enhancing the precision of intraoperative control.

[0038] The Y-shaped tube seat 5 is made of medical-grade PC material. One end is fixedly connected to the end of the stress relief tube 4 away from the outer tube body 2 by adhesive bonding. The other end has two independent interfaces: one interface is used to connect the injection device to inject the drug carrier into the balloon 3, and the interface is equipped with a sealing ring to prevent leakage during drug carrier injection; the other interface is used for guidewire insertion. The inner wall of the interface is smoothed, working in conjunction with the low-friction lubrication layer of the inner tube body 1 to ensure smooth guidewire insertion. The dual-interface design allows for independent drug injection and guidewire operation, eliminating the need for frequent instrument changes during surgery and simplifying the surgical procedure.

[0039] This invention discloses a method for forming an intracranial controllable drug-eluting balloon dilation catheter, specifically including the following steps: 1. Inner tube body 1 forming Using co-extrusion molding equipment, low-friction lubricating layer material (PTFE or polyethylene), supporting and reinforcing layer material (16-36 spindles braided structure / metal spring / metal hypo tube), and flexible adapter layer material (Nylon12, Pebax, or TPU) are simultaneously extruded in a radially layered structure to form the inner tube body 1 blank. The blank is then drawn into a cooling device for shaping to ensure the stability of the tube body shape. The flexible adapter layer is subjected to a hardness gradient treatment through a segmented heating and shaping process, so that the proximal hardness reaches Shore D60 and the distal hardness decreases to Shore D30, completing the molding of the inner tube body 1. After molding, the tube body diameter error is tested to be ≤±0.02mm to ensure that it meets the requirements for intracranial vascular delivery.

[0040] 2. Outer tube body 2 forming A winding device is used to form a support layer from a metal spring or braided structure, ensuring that the support layer is uniform and free of broken wires, thus guaranteeing torsional resistance. A coating device is used to coat the surface of the support layer with Nylon 12, Pebax, or TPU material, forming 2 to 5 layers of polymer material with gradually varying hardness. A laser drilling device is used to process 2 to 8 elliptical drug carrier filling holes 21 circumferentially at the pre-set balloon 3 assembly position. A platinum-iridium alloy or platinum-tungsten alloy imaging ring is placed at the far end of the outer tube 2, next to the drug carrier filling holes 21, ensuring that the imaging ring is firmly fixed without loosening, thus completing the forming of the outer tube 2.

[0041] 3. Balloon 3-plasty Nylon12, Pebax, or TPU raw materials are processed into balloon 3 preforms using extrusion equipment, ensuring that the concentricity of the preforms is ≥96% and the wall thickness is uniform. The preforms are heated and softened, then stretched to form a bubble, which is placed in a molding die with circumferential grooves. Compressed air is introduced to make the bubble conform to the inner wall of the die. After cooling and shaping, a balloon 3 prototype with grooves 31 is formed. Drug delivery holes 32 are machined in the grooves 31 using laser equipment. After drilling, the balloon 3 is placed in an oven for heat preservation to release internal stress and avoid deformation during subsequent expansion, thus completing the balloon 3 molding. After molding, the balloon 3 expansion diameter error is tested to be ≤±5% to ensure expansion accuracy.

[0042] 4. Preparation of drug adhesion layer and assembly of balloon 3 A special polyurethane material is coated on the surface of the balloon 3 assembly section of the outer tube 2 to form a drug adhesion layer; paclitaxel or rapamycin drug powder is evenly sprayed onto the surface of the drug adhesion layer by electrostatic spraying; the two tube feet of the balloon 3 are connected to the outer tube 2 at preset positions using laser welding equipment; after welding, a sealing test is performed by introducing 0.2MPa compressed air into the balloon to verify that there is no leakage of the drug carrier.

[0043] 5. Overall assembly Insert the inner tube 1 into the outer tube 2, adjust their positions to align their distal ends, and use a low-power laser welding machine to weld the distal end of the outer tube 2 to ensure connection strength. After welding, grind the weld points until smooth and burr-free. Bond one end of the stress relief tube 4 to the end of the outer tube 2 near the operating end with medical-grade epoxy resin. Bond the Y-shaped tube seat 5 to the other end of the stress relief tube 4, ensuring that the two interfaces of the Y-shaped tube seat 5 are connected to the cavity of the inner tube 1 and the gap between the outer tube 2 and the balloon 3, respectively. After bonding, check the sealing of the interfaces to complete the overall assembly.

[0044] In addition, the present invention also discloses a method for administering drugs to a narrowed vascular region via the above-mentioned intracranial controllable drug balloon dilation catheter, the specific steps of which are as follows: S1: Preoperative preparation and catheter delivery The guidewire is inserted through the instrument interface of the Y-shaped tube seat 5, and then through the lumen of the inner tube body 1 until the distal end of the guidewire crosses the stenotic area of ​​the intracranial blood vessel. Subsequently, the balloon 3 is pushed to the stenotic area of ​​the blood vessel along the extension trajectory of the guidewire. With the assistance of imaging equipment (such as X-ray fluoroscopy), the alignment accuracy of the balloon 3 with the stenotic area of ​​the blood vessel is confirmed by observing the position of the imaging ring, ensuring that the balloon 3 completely covers the lesion site. S2: Pre-dilation of balloon 3 and drug delivery injection The injection device is connected via the injection port of the Y-shaped port 5. An expansion medium (preferably physiological saline or iopromide) is slowly injected into the balloon 3. The balloon 3 is inflated to the preset pressure using a slow and uniform injection method to pre-dilate the narrowed blood vessel wall and create a suitable vascular environment for subsequent drug penetration. After pre-dilation, the balloon 3 is kept in an inflated state, and a drug carrier solution containing paclitaxel or rapamycin is injected through the same injection port until the drug carrier fills the internal cavity of the balloon 3, and the drug concentration matches the drug loading of the drug adhesion layer to ensure that the total amount of drug meets the treatment requirements. S3: Targeted drug release and penetration The inflation pressure of balloon 3 is kept stable to avoid pressure fluctuations affecting the uniformity of drug release. Under pressure, the drug carrier is evenly sprayed onto the surface of the blood vessel wall in the narrow area through the drug delivery port 32. At the same time, the adhesion force of balloon 3 to the blood vessel wall after inflation promotes the penetration of the drug carrier into the middle layer of the blood vessel wall, forming a synergistic effect of "surface coverage + deep penetration". After the drug carrier has finished spraying, the adhesion state between balloon 3 and blood vessel wall is maintained for a preset time to ensure full absorption of the drug. S4: Balloon 3 decompression and catheter withdrawal The residual drug carrier and expansion medium inside balloon 3 are slowly released through the injection device. After balloon 3 is fully contracted, the intracranial controllable drug balloon dilation catheter is slowly withdrawn in the opposite direction along the guidewire. The guidewire is left in the blood vessel for observation. After imaging equipment confirms that there is no thrombus formation in the stenotic area and that blood flow in the blood vessel is unobstructed, the guidewire is slowly withdrawn to complete the entire treatment process.

[0045] It is worth noting that Balloon 3 is made of non-compliant or semi-compliant materials, such as Nylon 12, Pebax, or TPU. These materials have good structural stability, with a diameter error of ≤±5% after balloon inflation, allowing for precise control of the degree of vascular dilation and avoiding over-dilation that could damage blood vessels. Simultaneously, its rupture pressure is ≥10 atm, far exceeding the safe pressure required for intracranial vascular dilation, ensuring that the balloon will not rupture due to excessive pressure during surgery and providing a guarantee for surgical safety.

[0046] It is also important to note that the drug adhesion layer requires uniformity testing during preparation. This involves observing the distribution of drug powder on the adhesion layer surface to ensure no drug agglomeration and a drug dosage deviation of ≤±0.1μg per square millimeter. Uniform drug distribution ensures that all parts of the diseased blood vessel wall receive the same dosage, avoiding differences in treatment efficacy due to uneven drug distribution and ensuring stable therapeutic results for each procedure.

[0047] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An intracranial controllable drug-eluting balloon dilation catheter, characterized in that, The device includes an inner tube, an outer tube, a balloon, a stress-relieving tube, and a Y-shaped connector. The inner tube is fitted inside the outer tube, and its distal end is fixedly connected to the distal end of the outer tube. The balloon is mounted on the outer tube and has multiple drug delivery ports along its circumference. The balloon section of the outer tube is coated with a drug adhesion layer. The stress-relieving tube is connected to the end of the outer tube near the operating end. The Y-shaped connector is connected to the end of the stress-relieving tube away from the outer tube, and one of its interfaces is used to connect an injection device to inject a drug carrier into the balloon, while the other interface is used for guidewire insertion.

2. The intracranial controllable drug-eluting balloon dilation catheter according to claim 1, characterized in that, The balloon is formed with multiple grooves, which are evenly distributed circumferentially along its central axis; the drug delivery holes are evenly distributed in each of the grooves.

3. The intracranial controllable drug-eluting balloon dilation catheter according to claim 1, characterized in that, Along its radial direction, the inner tube is composed of a low-friction lubrication layer, a support and reinforcement layer, and a flexible adaptation layer from the inside to the outside.

4. The intracranial controllable drug-eluting balloon dilation catheter according to claim 3, characterized in that, The low-friction lubricating layer is made of polytetrafluoroethylene or polyethylene; the supporting reinforcement layer is a spring body, a braided structure or a metal hyaluronic acid tube; the flexible adapter layer is made of Nylon12, Pebax or TPU and has a gradual change in hardness from the proximal end to the distal end.

5. The intracranial controllable drug-eluting balloon dilation catheter according to claim 1, characterized in that, Along its radial direction, the outer tube is composed of a support layer and a layer of polymer material with gradually varying hardness, arranged sequentially from the inside to the outside.

6. The intracranial controllable drug-eluting balloon dilation catheter according to claim 1, characterized in that, Corresponding to the assembly position of the balloon, the outer tube has multiple drug carrier filling holes evenly distributed along the circumference.

7. The intracranial controllable drug-eluting balloon dilation catheter according to claim 6, characterized in that, A contrast ring is provided at the distal end of the outer tube, next to the filling hole of the drug carrier.

8. A method for administering medication to a narrowed area of ​​a blood vessel, carried out using an intracranial controllable drug balloon dilation catheter as described in any one of claims 1-7, characterized in that, Includes the following steps: S1: Preoperative preparation and catheter delivery The guidewire is inserted through the instrument interface of the Y-shaped tube seat, and then through the cavity of the inner tube body until the distal end of the guidewire crosses the stenotic area of ​​the intracranial blood vessel; then the balloon is pushed to the stenotic area of ​​the blood vessel along the extension trajectory of the guidewire; and the alignment accuracy of the balloon with the stenotic area of ​​the blood vessel is confirmed with the assistance of imaging equipment. S2: Balloon pre-dilation and drug delivery injection The injection device is connected through the injection device interface of the Y-shaped tube seat, and the expansion medium is slowly injected into the balloon to inflate the balloon to a preset pressure, thereby pre-dilatating the narrowed blood vessel wall. After pre-dilation, the balloon is kept in an inflated state, and a drug carrier solution containing paclitaxel or rapamycin is injected through the same injection port until the drug carrier fills the internal cavity of the balloon and the drug concentration matches the drug loading of the drug adhesion layer. S3: Targeted drug release and penetration Maintaining the inflation pressure of the balloon, the drug carrier is evenly sprayed onto the surface of the blood vessel wall in the narrow area through the drug delivery port; at the same time, the adhesion force of the balloon to the blood vessel wall after inflation promotes the penetration of the drug carrier into the middle layer of the blood vessel wall. S4: Balloon decompression and catheter withdrawal The residual drug carrier and expansion medium inside the balloon are slowly released through the injection device. After the balloon is fully contracted, the intracranial controllable drug balloon dilation catheter is slowly withdrawn in the opposite direction along the guidewire. The guidewire is left in the blood vessel for observation. After imaging equipment confirms that there is no thrombus formation in the stenotic area and that blood flow in the blood vessel is unobstructed, the guidewire is then slowly withdrawn.

9. The method for administering medication to a vascular stenosis area according to claim 8, characterized in that, In step S2, the expansion medium is physiological saline or iopromide, and the expansion medium is injected into the balloon in a slow and uniform manner.

10. The method for administering medication to a vascular stenosis area according to claim 8, characterized in that, In step S3, during the process of the drug carrier being sprayed onto the surface of the blood vessel wall through the drug delivery orifice, the balloon inflation pressure is kept stable; and after the drug carrier has finished spraying, the balloon is kept in contact with the blood vessel wall for a preset time.

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