Balloon microcatheter for treating cerebrovascular stenosis

Abstract

The invention discloses a balloon micro-catheter for treating cerebrovascular stenosis, and particularly relates to the technical field of medical instruments.The balloon micro-catheter comprises a guide wire and a catheter body arranged outside the guide wire in a sleeving mode, a balloon is arranged on the catheter body, an expansion assembly used for inflating the interior of the balloon is arranged on the catheter body, and the balloon micro-catheter is connected with the guide wire. The balloon is connected with a support in a sleeved mode, and a fixing assembly is arranged on the balloon. When the catheter body moves in the blood vessel, the fixing assembly fixes the support to the balloon, and when the balloon expands, the fixing assembly is far away from the support. According to the balloon micro-catheter for treating cerebrovascular stenosis, the fixing assembly is arranged to abut against the two ends of the stent, and when the balloon expands, the fixing assembly is far away from the stent, so that the stability between the stent and the balloon is improved while supporting of the stent is not affected by the fixing assembly, the situation that the catheter punctures again in an operation is avoided as much as possible, and the operation efficiency is improved. And the operation success rate is increased.

Description

Technical Field

[0001] The invention relates to the technical field of medical devices, and in particular to a balloon microcatheter for treating cerebral vascular stenosis. Background Art

[0002] As is known, cerebral vascular stenosis is one of the main causes of stroke and other cerebrovascular diseases. Cerebral vascular stenosis is mainly caused by atherosclerosis, a disease that causes lipids and calcified substances to deposit on the inner wall of the blood vessel, which in turn causes the vascular lumen to narrow and hinders blood flow to the brain. Traditionally, the treatment methods for cerebral vascular stenosis include drug therapy and surgical treatment. Drug therapy mainly includes antiplatelet drugs and anticoagulants to prevent thrombosis and promote blood flow. However, drug therapy has limited effect on severely narrowed or completely occluded blood vessels. Surgical treatment includes intracranial and extracranial vascular bypass and carotid endarterectomy. Although these operations can directly solve the problem of vascular stenosis, they have high surgical risks and require high physical conditions for patients. In recent years, interventional therapy has gradually become an important method for treating cerebral vascular stenosis. Interventional therapy has the advantages of minimally invasive and fast recovery, and mainly includes intravascular stent implantation and balloon dilatation. Stent implantation implants a metal stent into the narrowed blood vessel segment to support the inner wall of the blood vessel and prevent re-stenosis.

[0003] For example, the Chinese patent document with the authorization announcement number CN112807553A, the announcement date 2021-05-18, and the name "A Balloon Microcatheter" includes a catheter, a balloon, a developing ring, a catheter seat, a first outer tube, a second outer tube, and a filling joint; the catheter is composed of a coaxial outer tube and an inner tube, the inner lumen of the catheter is a guidewire lumen, and the reinforcing rib structure on the catheter separates the annular channel between the inner tube and the outer tube into a first filling chamber and a second filling chamber, and a developing ring is fixedly connected to the catheter; the balloon is fixedly connected to the distal end of the catheter, and the inner lumen of the balloon is connected to the first filling chamber and the second filling chamber. The advantages of this invention: the preoperative balloon preparation is simpler and more thorough, which shortens the preoperative preparation time and avoids the problem of gas embolism or poor balloon development effect; improves the problem of bending of the balloon and the inner tube, and reduces the risk of excessive embolism caused by the "banana effect"; the balloon with a blocked filling channel can be retracted under a lower negative pressure, accelerating the balloon retraction process and reducing the accident rate.

[0004] The deficiency of the existing technology is that, during stent implantation, the stent is placed on a balloon, which enters the blood vessel through a catheter. When the balloon is placed at the location of blood vessel stenosis, the balloon is inflated to expand the stent, thereby achieving the purpose of supporting the blood vessel. However, when the balloon drives the stent through a tortuous position of the blood vessel, due to the connection method between the stent and the balloon, relative movement between the stent and the balloon is likely to occur, and the stent cannot accurately reach the location of blood vessel stenosis, and the stent needs to be re-placed for surgery, which increases the risk of surgery. Summary of the invention

[0005] The purpose of the present invention is to provide a balloon microcatheter for treating cerebral vascular stenosis to solve the above-mentioned deficiencies in the prior art.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A balloon microcatheter for treating cerebral vascular stenosis comprises a guide wire and a catheter body sleeved on the outside of the guide wire, a balloon is arranged on the catheter body, an expansion component for inflating the inside of the balloon is arranged on the catheter body, a stent is sleeved on the balloon, and a fixing component is arranged on the balloon;

[0008] When the catheter body moves inside a blood vessel, the fixing component fixes the stent on the balloon, and when the balloon expands, the fixing component moves away from the stent.

[0009] In the above-mentioned balloon microcatheter for treating cerebral vascular stenosis, the fixing assembly includes a plurality of abutments elastically arranged on the catheter body, and the abutments abut against the stent.

[0010] The above-mentioned balloon microcatheter for treating cerebral vascular stenosis is provided with a third through hole on the catheter body, a slider is provided in the sliding seal inside the third through hole, and the abutment is located on the movement stroke of the slider.

[0011] The above-mentioned balloon microcatheter for treating cerebral vascular stenosis has a catheter body provided with a sleeve, and a buffer component provided on the sleeve.

[0012] The above-mentioned balloon microcatheter for treating cerebral vascular stenosis, the buffer component includes a first sphere and a second sphere, and the first sphere is arranged outside the second sphere.

[0013] The above-mentioned balloon microcatheter for treating cerebral vascular stenosis has a ventilation cavity in the catheter body, the second sphere is connected to the ventilation cavity, and a ventilation component is arranged between the first sphere and the second sphere.

[0014] The above-mentioned balloon microcatheter for treating cerebral vascular stenosis, the ventilation component comprises a first through hole and a second through hole, the first through hole and the second through hole are both arranged on the sleeve, the first through hole is connected to the second sphere, and the second through hole is connected to the first sphere and the first through hole;

[0015] A blocking plate is slidably disposed in the first through hole. The blocking plate has a first position for blocking the first through hole and the second through hole, and a second position for connecting the first through hole and the second through hole.

[0016] The above-mentioned balloon microcatheter for treating cerebral vascular stenosis is provided with air guide holes on the blocking plate.

[0017] In the above-mentioned balloon microcatheter for treating cerebral vascular stenosis, a fixing block is arranged on the blocking plate, a sliding groove is opened on the first through hole, and an elastic sheet is arranged between the fixing block and the sliding groove.

[0018] The above-mentioned balloon microcatheter for treating cerebral vascular stenosis has a catheter base on the catheter body, a Y-shaped connector on the catheter base, an inner cavity on the Y-shaped connector, and the inner cavity is connected to the ventilation cavity.

[0019] In the above technical scheme, the present invention provides a balloon microcatheter for treating cerebral vascular stenosis, in which a fixing component is arranged to abut the two ends of a stent, and when the balloon is inflated, the fixing component is away from the stent, so that the fixing component does not affect the support of the stent while increasing the stability between the stent and the balloon, thereby avoiding re-puncture of the catheter during the operation as much as possible and increasing the success rate of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0021] Figure 1 A schematic diagram of the overall structure provided by an embodiment of the present invention;

[0022] Figure 2 A schematic cross-sectional view of the catheter body during the process of entering a blood vessel provided by another embodiment of the present invention;

[0023] Figure 3 for Figure 2 A schematic diagram of the enlarged local structure at center A;

[0024] Figure 4 for Figure 3 A magnified schematic diagram of the local structure at B in the middle;

[0025] Figure 5 A schematic cross-sectional view of a bracket provided by another embodiment of the present invention when it is fully propped up;

[0026] Figure 6 for Figure 5 A magnified schematic diagram of the local structure at C in the middle;

[0027] Figure 7 for Figure 6 The enlarged schematic diagram of the local structure at D in the middle;

[0028] Figure 8 A schematic cross-sectional view of the structure when the air guide hole provides connection between the first through hole and the second through hole according to another embodiment of the present invention;

[0029] Fig. 9 for Figure 8 The enlarged schematic diagram of the local structure at E in the middle;

[0030] Fig.10 for Fig. 9 Enlarged schematic diagram of the local structure at point F in the middle.

[0031] Description of reference numerals:

[0032] 1. Catheter body; 2. Guidewire cavity; 3. Bracket; 4. Abutment; 401. First section; 402. Second section; 5. Axial groove; 6. Sleeve; 7. First sphere; 8. Second sphere; 9. Ventilation cavity; 10. Vent; 11. First through hole; 12. Second through hole; 13. Blocking plate; 14. Air guide hole; 15. Slider; 16. Slide groove; 17. Fixing block; 18. Elastic sheet; 19. Catheter base; 20. Y-type connector; 21. Inner cavity; 22. Screw cap; 24. Third through hole; 25. Balloon. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0034] In the description of the present invention, it should be understood that the terms "center", "length", "width", "degree", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0035] Reference Figure 1-10 An embodiment of the present invention provides a balloon microcatheter for treating cerebral vascular stenosis, comprising a guidewire and a catheter body 1 sleeved on the outside of the guidewire, a balloon 25 is arranged on the catheter body 1, an expansion component for inflating the inside of the balloon 25 is arranged on the catheter body 1, a stent 3 is sleeved on the balloon 25, and a fixing component is arranged on the balloon 25; when the catheter body 1 moves inside the blood vessel, the fixing component fixes the stent 3 on the balloon 25, and when the balloon 25 expands, the fixing component moves away from the stent 3.

[0036] Specifically, when treating cerebral vascular stenosis, after establishing a pathway by puncturing the femoral artery, a guiding catheter is introduced to the vicinity of the lesion, and a guide wire (not shown) is introduced through the guiding catheter. A guide wire cavity 2 is provided in the catheter body 1, and the guide wire cavity 2 runs through the catheter body 1. The radial size of the guide wire cavity 2 is adapted to the guide wire. The guide wire introduces the catheter body 1 into the blood vessel. A balloon 25 is provided on the catheter body 1, and a stent 3 is sleeved on the outer surface of the balloon 25. The stent 3 is made of metal. When the internal force is applied, it is propped up and does not retract. After the stent 3 is expanded, the outer diameter is the same as the inner diameter of a normal blood vessel. The balloon 25 in a contracted state is guided by the guide wire to reach the narrow area in the blood vessel. There are multiple vents 10, and the catheter body 1 is provided with an expansion component for inflating the balloon 25. The expansion component inflates the balloon 25 through the vent 10 to expand it. After the balloon 25 is inflated, it carries the stent 3 to support the narrow part of the blood vessel. The stent 3 and the balloon 25 jointly apply a force to the narrow part of the blood vessel, so that the blood vessel adapts to the shape of the balloon 25 and the stent 3. After the gas in the balloon 25 is pumped out, the balloon 25 retracts, and the balloon 25 can be withdrawn from the stent 3 by moving the catheter body 1. After the catheter body 1 withdraws from the blood vessel, the stent 3 is still supported in the diseased blood vessel, so that the narrowed area of ​​the blood vessel cannot be restored, thereby ensuring the dredging of the blood vessel. This is a prior art and will not be repeated. One of the core innovations of the embodiment of the present invention is that a fixing component is provided on the balloon 25, and the fixing components are distributed at both ends of the balloon 25. When the stent 3 is propped up, the fixing component is away from the stent 3, that is, the fixing component releases the fixation of the stent 3 when the balloon 25 is propped up. In the operation for treating cerebral vascular stenosis, the catheter body 1 needs to carry the balloon 25 and the stent 3 to the stenosis of the blood vessel, during which there are tortuous blood vessels. Since the fixing method of the stent 3 and the balloon 25 is only sleeve connection, when passing through the tortuous blood vessel, the blood vessel exerts a force on the stent 3 and the balloon 25, so that there is a possibility of displacement of the balloon 25 and the stent 3. Therefore, when the catheter body 1 slides in the blood vessel, the stent 3 is fixed to the balloon 25 by the fixing component, and the movement between the balloon 25 and the stent 3 is avoided as much as possible. In this way, when the balloon 25 is positioned in the vascular lesion area, the stent 3 is accurately positioned in the vascular lesion area, thereby supporting the stenosis of the blood vessel, reducing the probability of the position of the stent 3 and the balloon 25 being offset, thereby increasing the success rate of the operation.

[0037] Preferably, the fixing assembly includes a plurality of abutments 4 elastically arranged on the catheter body 1, and the abutments 4 abut against the stent 3. Specifically, the abutment 4 includes a first section 401 and a second section 402, and preferably there are four abutments 4, which are respectively arranged on the catheter body 1 at both ends of the stent 3 to fix the stent 3. An axial groove 5 is arranged on the catheter body 1. The abutment 4 is made of elastic material as a whole, so that the abutment 4 can rotate around the position connected to the axial groove 5, and the connection position (the connection area between the first section 401 and the catheter body 1) will be deformed and force will be accumulated during the rotation of the abutment 4. There is an obtuse angle between the first section 401 and the second section 402. When the first section 401 rotates to be perpendicular to the catheter body 1, the distance between the two abutments 4 away from each other at one end in the radial direction is adapted to the inner diameter of the normal blood vessel (and the abutment 4 itself can be bent to deform the blood vessel). The radial size of the tube is adapted), when the catheter body 1 enters the blood vessel, the second section 402 abuts against the outer wall of the stent 3, and when the balloon 25 reaches the narrow part of the blood vessel, the balloon 25 is inflated, and the stent 3 is expanded during the expansion of the balloon 25. During the expansion of the stent 3, its edge position will drive the abutment 4 to swing away from the stent 3 and accumulate force for the abutment 4 itself. When the stent 3 is further expanded, the abutment 4 will move away from the stent 3. At this time, the elastic force of the abutment 4 itself is released to achieve automatic resetting of the abutment 4. At this time, the abutment 4 abuts against the balloon 25. When the balloon 25 is deflated, the abutment 4 will also rotate in the direction of the balloon 25, so that the abutment 4 and the catheter body 1 can exit the blood vessel together.

[0038] As another embodiment of the present invention, the catheter body 1 is provided with a third through hole 24, and a slider 15 is provided in the third through hole 24 as a sliding seal, and the abutment 4 is located on the movement stroke of the slider 15. Specifically, the slider 15 is provided in the third through hole 24, and the third through hole 24 is connected with the axial groove 5 and the vent 10. The length of the slider 15 is greater than the length of the axial groove 5, so that the slider 15 does not separate from the axial groove 5, and the radial dimension of the connection position between the vent 10 and the third through hole 24 is smaller than the radial dimension of the slider 15, so that the slider 15 does not enter the vent 10, and the force required for the balloon 25 to expand is smaller than the force required for the slider 15 to push the abutment 4 to rotate. The effect of such a setting is that when the catheter body 1 reaches the narrow part of the blood vessel, the end of the vent 10 close to the guidewire cavity 2 is inflated, and the gas will generate an extrusion force on the slider 15, so that the slider 15 slides in the direction close to the abutment 4, and the slider 15 abuts against the abutment 4, so that the abutment 4 moves away from the stent 3. , at this time, the abutment 4 changes from an inclined state to a vertical state. When the abutment 4 is in a vertical state, the end thereof away from the axial groove 5 abuts against the inner wall of the blood vessel (the abutment 4 itself is made of elastic material and can be bent to adapt to blood vessels of different sizes). When the blood vessel is expanded, the balloon 25 is depressurized, and the force of the gas on the slider 15 disappears. At this time, the elastic force of the abutment 4 is released to realize automatic resetting of the abutment 4. The benefits brought by the abutment 4 in this process are, first, it abuts against the bracket 3 to fix the position of the bracket 3. Second, it drives the abutment 4 away from the bracket 3 to realize passive unlocking of the bracket 3. Third, when the abutment 4 is transferred from the inclined state to the vertical state, it abuts against the inner wall of the blood vessel to realize flexible positioning of the balloon 25, thereby improving the stability of the balloon 25 during expansion.

[0039] As another embodiment provided by the present invention, a sleeve 6 is provided on the catheter body 1, and a buffer component is provided on the sleeve 6. Specifically, the sleeve 6 is sleeved on the catheter body 1, and preferably two sleeves 6 are respectively located at two ends of the catheter body 1 with respect to the stent 3. The sleeve 6 is provided with a buffer component, and when the balloon 25 is inflated, the balloon 25 can be expanded. Since the expansion of the balloon 25 will exert a force on the blood vessel, there may be a situation where the balloon 25 expands rapidly and causes the blood vessel to rupture. The buffer component allows the balloon 25 to be slowly inflated, further ensuring the safety of the operation.

[0040] Preferably, the buffer assembly includes a first sphere 7 and a second sphere 8, wherein the first sphere 7 is arranged outside the second sphere 8; a ventilation cavity 9 is arranged in the catheter body 1, the second sphere 8 is connected to the ventilation cavity 9, and a ventilation assembly is arranged between the first sphere 7 and the second sphere 8. Specifically, that is, in this embodiment, the balloon 25 is divided into an inner and outer layer, the two ends of the first sphere 7 are respectively fixed to the two sleeves 6, the two ends of the second sphere 8 are also fixed to the two sleeves 6, the first sphere 7 completely covers the outer surface of the second sphere 8, the ventilation cavity 9 is arranged in the catheter body 1, and its radius is larger than the diameter of the guidewire cavity 2, and is not connected to the guidewire cavity 2, the vent 10 connects the ventilation cavity 9 with the second sphere 8, and a ventilation assembly is arranged between the first sphere 7 and the second sphere 8. When the first sphere 7 and the second sphere 8 reach the narrowed part of the blood vessel, they are inflated through the ventilation cavity 9, and the gas is discharged from the vent 1 0 enters the second sphere 8. During the inflation process, the second sphere 8 will drive the first sphere 7 and the bracket 3 to prop up. When the second sphere 8 reaches the maximum expansion volume, the second sphere 8 inflates the first sphere 7 through the ventilation component, so that the first sphere 7 reaches the maximum expansion volume. At this time, the outer wall of the bracket 3 is in close contact with the inner wall of the blood vessel. The purpose of such a setting is that the second sphere 8 inflates the first sphere 7, which buffers the expansion speed of the first sphere 7 and makes the blood vessel more evenly stressed. At the same time, when the second sphere 8 is full, it can be used as a staged observation to determine whether to continue to inflate the first sphere 7.

[0041] Preferably, the ventilation assembly includes a first through hole 11 and a second through hole 12, the first through hole 11 and the second through hole 12 are both arranged on the sleeve 6, the first through hole 11 is connected to the second sphere 8, and the second through hole 12 is connected to the first sphere 7 and the first through hole 11; a blocking plate 13 is slidably arranged in the first through hole 11, and the blocking plate 13 has a first position for blocking the first through hole 11 and the second through hole 12, and the blocking plate 13 has a second position for connecting the first through hole 11 and the second through hole 12. Specifically, the radial dimensions of the first through hole 11 and the second through hole 12 are smaller than the radial dimensions of the vent 10, the first through hole 11 penetrates the sleeve 6 in the axial direction, the first sphere 7 is connected to the second sphere 8 through the first through hole 11 and the second through hole 12, a blocking plate 13 is provided in the first through hole 11 for sliding sealing, the blocking plate 13 is approximately L-shaped, the length of its horizontal section is greater than the length of its vertical section, and the vertical section of the blocking plate 13 is provided with an inclined surface toward the abutment 4 in the direction close to the abutment 4, the horizontal section of the blocking plate 13 is slidably provided in the first through hole 11, and during the process of the catheter body 1 entering the blood vessel, the blocking plate 13 is located in the first position, at which time the blocking plate 13 is vertically The first sphere 8 is inflated with air in the second position, and the second sphere 8 is inflated with air in the second position.

[0042] In order to facilitate the switching of the blocking plate 13 between the first position and the second position, preferably, a fixing block 17 is provided on the blocking plate 13, a sliding groove 16 is opened on the first through hole 11, and an elastic sheet 18 is provided between the fixing block 17 and the sliding groove 16; and an air guide hole 14 is provided on the blocking plate 13. Specifically, the slide groove 16 is opened on the inner wall of the first through hole 11, the fixed block 17 is a protruding structure on the blocking plate 13, and the elastic sheet 18 is also made of elastic material, that is, after it is elastically deformed by pressure, it has the ability to automatically recover. The air guide hole 14 is approximately L-shaped, and the horizontal section of the air guide hole 14 is parallel to the first through hole 11, and the vertical section is parallel to the second through hole 12. The elastic force provided by the resisting member 4 itself is greater than the force required for the elastic sheet 18 to deform. The effect of such a setting is that when the second sphere 8 reaches the maximum expansion volume, it continues to be inflated so that the blocking plate 13 is under pressure, which drives the fixed block 17 to move toward the resisting member 4 and forces the elastic sheet 18 to undergo elastic deformation and accumulate force. When the blood vessel is expanded, the second sphere 8 is depressurized. At this time, the elastic force of the elastic sheet 18 is released, so that the blocking plate 1 3 moves toward the direction of the second sphere 8 to realize the automatic reset of the blocking plate 13. At this time, the gas inside the first sphere 7 has not been released yet. To solve this problem, the elastic force of the abutment 4 is released at this time to realize the reverse rotation of the abutment 4. Since in this process, the stent 3 supports the blood vessel and does not return, that is, the stent 3 remains inside the blood vessel, the abutment effect of the stent 3 will be reduced. At this time, the abutment 4 will further rotate in the reverse direction, that is, the reverse rotation angle of the abutment 4 will be greater than the previous forward rotation angle, so that the abutment 4 will abut against the vertical section of the blocking plate 13 and force the blocking plate 13 to move further in the direction of the second sphere 8, that is, the two ends of the air guide hole 14 connect the first sphere 7 with the second sphere 8, so that the passive pressure relief of the first sphere 7 can be completed, so as to facilitate the extraction of the balloon 25 from the blood vessel.

[0043] In summary, the abutment 4 has the following advantages: first, it abuts against the stent 3 to improve the stability of the stent 3 during transportation; second, it abuts against the blood vessel to achieve flexible positioning of the balloon 25; third, it drives the air guide hole 14 to connect the first through hole 11 and the second through hole 12 to achieve passive pressure relief of the first sphere 7.

[0044] In order to facilitate the introduction of the catheter body 1 into the blood vessel and to facilitate the inflation of the ventilation cavity 9, a catheter base 19 is provided on the catheter body 1, and a Y-type connector 20 is provided on the catheter base 19. An inner cavity 21 is provided on the Y-type connector 20, and the inner cavity 21 is connected to the ventilation cavity 9. Specifically, a catheter base 19 is provided at the proximal end of the catheter body 1, and the catheter body 1 is sleeved in the catheter base 19, and a Y-type connector 20 is provided on the catheter base 19, that is, the Y-type connector 20 and the catheter base 19 form an angle, and an inner cavity 21 is provided in the Y-type connector 20, and the inner cavity 21 is connected to the ventilation cavity 9. A screw cap 22 is provided at the end of the Y-type connector 20, and the screw cap 22 is threadedly connected to the Y-type connector 20. When the device is used, the screw cap 22 is screwed down, and the expansion assembly inflates the ventilation cavity 9 through the connection inner cavity 21, and the gas entering causes the first sphere 7 and the second sphere 8 to expand.

[0045] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A balloon microcatheter for treating cerebral vascular stenosis, comprising a guide wire and a catheter body sleeved on the outside of the guide wire, a balloon is arranged on the catheter body, an expansion component for inflating the inside of the balloon is arranged on the catheter body, and a stent is sleeved on the balloon, characterized in that: The balloon is provided with a fixing component; When the catheter body moves inside a blood vessel, the fixing component fixes the stent on the balloon, and when the balloon expands, the fixing component moves away from the stent.

2. A balloon microcatheter for treating cerebral vascular stenosis according to claim 1, characterized in that: The fixing assembly includes a plurality of abutments elastically arranged on the catheter body, and the abutments abut against the bracket.

3. A balloon microcatheter for treating cerebral vascular stenosis according to claim 2, characterized in that: The catheter body is provided with a third through hole, a slider is provided in the third through hole for sliding sealing, and the abutment is located on the movement stroke of the slider.

4. The balloon microcatheter for treating cerebral vascular stenosis according to claim 1, characterized in that: The catheter body is provided with a sleeve, and the sleeve body is provided with a buffer component.

5. The balloon microcatheter for treating cerebral vascular stenosis according to claim 3, characterized in that: The buffer assembly includes a first sphere and a second sphere, wherein the first sphere is disposed outside the second sphere.

6. The balloon microcatheter for treating cerebral vascular stenosis according to claim 4, characterized in that: A ventilation cavity is arranged in the catheter body, the second sphere is connected to the ventilation cavity, and a ventilation component is arranged between the first sphere and the second sphere.

7. The balloon microcatheter for treating cerebral vascular stenosis according to claim 5, characterized in that: The ventilation assembly comprises a first through hole and a second through hole, wherein the first through hole and the second through hole are both arranged on the sleeve body, the first through hole is communicated with the second sphere, and the second through hole is communicated with the first sphere and the first through hole; A blocking plate is slidably disposed in the first through hole. The blocking plate has a first position for blocking the first through hole and the second through hole, and a second position for connecting the first through hole and the second through hole.

8. The balloon microcatheter for treating cerebral vascular stenosis according to claim 6, characterized in that: The blocking plate is provided with air guide holes.

9. The balloon microcatheter for treating cerebral vascular stenosis according to claim 6, characterized in that: The blocking plate is provided with a fixing block, the first through hole is provided with a sliding groove, and an elastic sheet is provided between the fixing block and the sliding groove.

10. The balloon microcatheter for treating cerebral vascular stenosis according to claim 5, characterized in that: The catheter body is provided with a catheter base, the catheter base is provided with a Y-shaped connector, the Y-shaped connector is provided with an inner cavity, and the inner cavity is connected with the ventilation cavity.

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