Conical dilating catheter for artificial internal arteriovenous fistula stenosis

Abstract

The invention relates to a conical dilating catheter for artificial internal arteriovenous fistula stenosis, and relates to the technical field of medical instruments. Comprising a catheter body, an expansion part, a pressure control assembly and a filling assembly. The expansion piece is arranged on the periphery of the catheter body and is conical; the multiple pressure control assemblies are arranged on the expansion part at intervals, and the interior of the expansion part is divided into multiple containing spaces by the multiple pressure control assemblies; and the filling assembly communicates with the expansion part and is used for filling the expansion part with a filling agent. The conical design of the expansion piece is easier to pass through narrow positions. By means of the segmented separation and step-by-step expansion structure of the pressure control assembly, the single catheter body integrates the small-medium-large expansion function, expansion pieces do not need to be replaced many times, consumption of consumables is reduced, and the medical cost is reduced; meanwhile, repeated withdrawing and feeding of the catheter body are avoided, the operation time is shortened, and related operation risks such as guide wire displacement and thrombus falling are reduced.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a tapered dilation catheter for stenosis of artificial arteriovenous fistula. Background Technology

[0002] Patients with chronic renal failure rely on hemodialysis to maintain their lives, and arteriovenous fistulas (AVFs) are the preferred dialysis access. These fistulas connect an artery and a superficial vein, allowing the vein to expand and thicken under the impact of arterial blood flow to accommodate dialysis punctures. However, the sudden drop in pressure at the anastomosis site, the impact of high blood flow, and repeated puncture damage can easily lead to intimal hyperplasia, causing stenosis of the anastomosis and venous segment, which is the main cause of fistula failure.

[0003] Currently, percutaneous endovascular angioplasty is used clinically to treat stenosis, which involves dilating and tearing the proliferating intima using dilators. However, existing dilators have significant drawbacks: firstly, their uniform diameter design cannot accommodate the "narrower at the front and wider at the back" vascular structure; small dilators result in insufficient dilation, while large dilators are prone to vascular rupture; secondly, long stenosis segments or those with significant diameter differences require multiple dilator replacements, increasing medical costs and surgical risks. Therefore, there is an urgent need for a novel dilator catheter based on structural optimization to address these technical challenges.

[0004] Regarding the aforementioned technologies, there is a problem with the poor compatibility of existing tapered dilation catheters used for stenosis of artificial arteriovenous fistulas. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a tapered dilation catheter for stenosis of artificial arteriovenous fistula, which aims to solve the problem of poor adaptability of existing tapered dilation catheters for stenosis of artificial arteriovenous fistula.

[0006] This application provides a tapered dilation catheter for arteriovenous fistula stenosis, employing the following technical solution: A tapered dilation catheter for arteriovenous fistula stenosis, comprising: Catheter body; An expansion member is disposed on the outer periphery of the catheter body, and the expansion member is tapered in shape. Multiple pressure control components are provided, and the multiple pressure control components are spaced apart on the expansion member. The multiple pressure control components divide the interior of the expansion member into multiple receiving spaces. The pressure control components are used to control the connection between two adjacent receiving spaces. A filling component, connected to the expansion member, is used to fill the expansion member with a filler.

[0007] Optionally, the expansion member includes a front end section, a middle section, and a rear end section, the diameters of the front end section, the middle section, and the rear end section increasing sequentially, a front end space being formed in the front end section, a middle section space being formed in the middle section, and a rear end space being formed in the rear end section. Two pressure control components are provided, one between the front end section and the other between the middle section and the other between the middle section and the rear end section.

[0008] Optionally, a first transition arc is provided between the front end segment and the middle segment, and a second transition arc is provided between the middle segment and the rear end segment.

[0009] Optionally, the pressure control component includes a pressure membrane disposed between the front end segment and the middle segment or between the middle segment and the rear end segment, the pressure membrane being used to isolate the front end space from the middle segment space or to isolate the middle segment space from the rear end space.

[0010] Optionally, the pressure control assembly includes a restraint ring disposed on the outside of the pressure diaphragm.

[0011] Optionally, the restraining ring is coaxially arranged with the pressure diaphragm, and the outer diameter of the restraining ring is consistent with the outer diameter of the expansion member after expansion at the corresponding position.

[0012] Optionally, the outer periphery of the expansion member is provided with scoring wires.

[0013] Optionally, the scoring wires are spirally distributed around the outer periphery of the expander.

[0014] Optionally, the filling assembly includes a filler and a filling tube, the filling tube connecting the filler and the expansion member.

[0015] Optionally, the filling tube is in communication with the front end space.

[0016] Compared with the prior art, the embodiments of the present invention have the following advantages: The tapered design of the dilator makes it easier to pass through narrow locations. The segmented and step-by-step dilation structure of the pressure control component allows a single catheter body to integrate dilation functions from small to medium to large, eliminating the need for multiple dilator replacements, reducing consumable usage, and lowering medical costs. At the same time, it avoids repeated withdrawal and insertion of the catheter body, shortening the operation time and reducing operation-related risks such as guidewire displacement and thrombus dislodgement. Attached Figure Description

[0017] 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 recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the catheter body and the dilator disposed outside it of a tapered dilator catheter for stenosis of an artificial arteriovenous fistula according to an embodiment of this application. Figure 2 This is a cross-sectional view of the catheter body and dilator of a tapered dilator catheter used for stenosis of an artificial arteriovenous fistula in an embodiment of this application; Figure 3 yes Figure 2 Enlarged view of section A; Figure 4 This is a schematic diagram of the structure of a pressure control component of a tapered dilation catheter for stenosis of an artificial arteriovenous fistula in an embodiment of this application; Figure 5 This is an exploded view of a pressure control assembly for a tapered dilation catheter used for stenosis of an artificial arteriovenous fistula in an embodiment of this application; Figure 6 This is a schematic diagram of the pressure membrane of a tapered dilation catheter used for stenosis of an artificial arteriovenous fistula in an embodiment of this application; Figure 7 This is a schematic diagram of the filling component of a tapered dilation catheter for stenosis of an artificial arteriovenous fistula in an embodiment of this application.

[0019] Explanation of reference numerals in the attached figures: 1. Catheter body; 11. First branch; 12. Second branch; 13. Guidewire channel; 14. Filling channel; 2. Expander; 21. Front end section; 211. Front end space; 22. Middle section; 221. Middle section space; 23. Rear end section; 231. Rear end space; 24. First transition arc; 25. Second transition arc; 26. Scoring wire; 3. Pressure control assembly; 31. Pressure diaphragm; 311. Pre-splitting groove; 32. Restraint ring; 321. Connecting rod; 4. Filling assembly; 41. Filler; 42. Filling tube. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The present application will be further described in detail below with reference to the accompanying drawings.

[0022] This application discloses a tapered dilation catheter for stenosis of an artificial arteriovenous fistula.

[0023] like Figure 1 , Figure 2 and Figure 7 As shown, a tapered dilation catheter for stenosis of an artificial arteriovenous fistula includes a catheter body 1, a dilator 2, a pressure control assembly 3, and a filling assembly 4. The dilator 2 is disposed on the outer periphery of the catheter body 1 and is tapered in shape. Multiple pressure control assemblies 3 are provided and spaced apart on the dilator 2. The multiple pressure control assemblies 3 divide the interior of the dilator 2 into multiple receiving spaces, and the pressure control assemblies 3 are used to control the conduction between two adjacent receiving spaces. The filling assembly 4 is connected to the dilator 2 and is used to fill the dilator 2 with a filler.

[0024] The tapered design of the dilator 2 makes it easier to pass through narrow locations. The segmented and step-by-step expansion structure of the pressure control component 3 allows a single catheter body 1 to integrate "small → medium → large" expansion functions, eliminating the need for multiple replacements of the dilator 2, reducing consumable usage, and lowering medical costs. At the same time, it avoids repeated withdrawal and insertion of the catheter body 1, shortening the operation time and reducing operation-related risks such as guidewire displacement and thrombus dislodgement.

[0025] like Figure 1 and Figure 2 As shown, the expansion member 2 includes a front section 21, a middle section 22, and a rear section 23. The diameters of the front section 21, the middle section 22, and the rear section 23 increase sequentially. A front space 211 is formed in the front section 21, a middle space 221 is formed in the middle section 22, and a rear space 231 is formed in the rear section 23. Two pressure control components 3 are provided, and the two pressure control components 3 are respectively located between the front section 21 and the middle section 22 and between the middle section 22 and the rear section 23.

[0026] Specifically, the three-segment diameter-increasing structural design of the dilator 2 can match the anatomical characteristics of blood vessels that are "thin at the front and thick at the back," ensuring that each segment fits the corresponding blood vessel segment during the dilation process. This avoids over-dilation of the front segment 21, which could damage the artery, while ensuring that the rear segment 23 dilates sufficiently to tear the stenotic tissue of the venous segment.

[0027] The two pressure control components 3 correspond to the separation positions of "front end segment 21-middle segment 22" and "middle segment 22-rear end segment 23" respectively, realizing the independent separation of the three containment spaces and providing a structural basis for step-by-step expansion.

[0028] like Figure 1 As shown, a first transition arc 24 is provided between the front end segment 21 and the middle segment 22, and a second transition arc 25 is provided between the middle segment 22 and the rear end segment 23.

[0029] Specifically, the arrangement of the first transition arc 24 and the second transition arc 25 can eliminate the sharp edges between the segments of the expansion member 2.

[0030] Since the dilator 2 needs to be in close contact with the vascular intima after dilation, if the transition between segments is at a right angle, it is easy to scrape or compress the vascular intima during dilation, leading to intimal damage and postoperative thrombosis. The arc transition design makes the surface of the dilator 2 smooth and continuous, and it makes surface contact with the vascular intima during dilation, dispersing pressure, reducing the risk of intimal damage, and improving the smoothness of the dilator 2 through curved blood vessels or narrowed areas.

[0031] like Figure 2 , Figure 4 and Figure 5 As shown, the pressure control assembly 3 includes a pressure membrane 31, which is disposed between the front end section 21 and the middle section 22 or between the middle section 22 and the rear end section 23. The pressure membrane 31 is used to isolate the front end space 211 and the middle section space 221 or to isolate the middle section space 221 and the rear end space 231.

[0032] Specifically, the pressure membrane 31 is an annular thin sheet structure. Its outer ring is sealed to the inner wall of the expansion member 2, and its inner ring is fixedly connected to the outer periphery of the conduit body 1, ensuring that the two adjacent receiving spaces (front end space 211 and middle section space 221, middle section space 221 and rear end space 231) are completely isolated before the pressure membrane 31 ruptures, and there is no leakage of filler.

[0033] Furthermore, such as Figure 2 , Figure 4 and Figure 6As shown, the edge of the pressure membrane 31 is provided with a pre-rupture groove 311. The depth of the pre-rupture groove 311 is 1 / 2 to 2 / 3 of the thickness of the pressure membrane 31. The pre-rupture groove 311 is provided to precisely control the rupture position and rupture pressure. Among them, the rupture pressure of the pressure membrane 31 between the front end section 21 and the middle section 22 is less than the rupture pressure of the pressure membrane 31 between the middle section 22 and the rear end section 23.

[0034] For example, the rupture pressure of the pressure membrane 31 between the front segment 21 and the middle segment 22 is set to 8-10 standard atmospheres (atm) to meet the pressure requirements for arterial segment expansion (avoiding excessive pressure that could damage the artery); the rupture pressure of the pressure membrane 31 between the middle segment 22 and the rear segment 23 is set to 12-15 atm to meet the expansion pressure requirements of the venous segment stenosis.

[0035] When the filler is filled into a certain containment space, and the internal pressure reaches the rupture pressure of the corresponding pressure membrane 31, the pressure membrane 31 is precisely broken along the pre-splitting groove 311, realizing the conduction of adjacent containment spaces and completing the step-by-step expansion.

[0036] like Figure 2 , Figure 4 and Figure 5 As shown, the pressure control assembly 3 includes a restraint ring 32, which is disposed on the outside of the pressure diaphragm 31.

[0037] Specifically, the restraint ring 32 is disposed on the outside of the pressure membrane 31 and located on the inner surface of the expansion member 2, and the outer diameter of the restraint ring 32 is fixedly connected to the inner surface of the expansion member 2.

[0038] The pressure membrane 31 is fixed on the inner ring of the restraint ring 32 to isolate two adjacent receiving spaces; a connecting rod 321 is provided on the restraint ring 32, the connecting rod 321 passes through the center of the restraint ring 32, and the restraint ring 32 is fixedly connected to the catheter body 1 through the connecting rod 321.

[0039] The restraint ring 32 is a ring-shaped rigid structure. Its outer diameter and the inner surface of the expansion member 2 can be sealed and fixed by medical adhesives to ensure that there is no leakage of filler at the connection. At the same time, it locks the axial position of the restraint ring 32 in the expansion member 2 to prevent displacement as the expansion member 2 expands.

[0040] The pressure membrane 31 is an annular thin sheet structure. Its outer periphery is sealed and fixed to the inner ring of the restraining ring 32, forming an integrated structure of "restraining ring 32-pressure membrane 31". Compared with the pressure membrane 31 being directly fixed to the inner wall of the expansion member 2, this design can, on the one hand, limit excessive deformation in this area, ensure that the pressure membrane 31 always remains flat, and ensure that the pre-cracked groove 311 ruptures accurately under the design pressure; on the other hand, the fixed connection between the restraining ring 32 and the expansion member 2 can enhance the installation stability of the pressure membrane 31, prevent the pressure membrane 31 from detaching from the expansion member 2 or the conduit body 1 during repeated expansion and contraction, and can greatly improve the structural stability of the pressure membrane 31, preventing the pressure membrane 31 from warping at the edges due to its thinness.

[0041] The connecting rod 321 is made of a rigid material (such as medical stainless steel or nickel-titanium alloy) to ensure connection strength without affecting the expansion action of the expansion member 2. It is evenly distributed along the inner circumference of the restraint ring 32. One end of the connecting rod 321 is fixedly connected to the inner ring of the restraint ring 32, and the other end extends towards the axis of the catheter body 1 and is fixedly connected to the outer circumference of the catheter body 1.

[0042] The number of connecting rods 321 is set to at least two. In this embodiment, two rods are provided. This number can ensure the stability of the connection and avoid too many connecting rods 321 occupying the central space.

[0043] like Figure 2 , Figure 4 and Figure 5 As shown, the restraint ring 32 is coaxially arranged with the pressure diaphragm 31, and the outer diameter of the restraint ring 32 is consistent with the outer diameter of the expansion member 2 after expansion at the corresponding position.

[0044] Specifically, the outer diameter of the restraint ring 32 is exactly the same as the outer diameter of the dilator 2 after expansion at the corresponding position (e.g., the outer diameter of the restraint ring 32 between the front end segment 21 and the middle segment 22 = the diameter of the middle segment 22 after expansion, and the outer diameter of the restraint ring 32 between the middle segment 22 and the rear end segment 23 = the diameter of the rear end segment 23 after expansion). The purpose is to ensure that after the dilator 2 is expanded, the outer surface of the restraint ring 32 is flush with the outer surface of the dilator 2, without any protrusions or depressions. If the outer diameter of the restraint ring 32 is larger than the outer diameter of the dilator 2 after expansion, a protrusion will be formed, which will scrape the vascular intima during expansion. If the outer diameter is smaller than the outer diameter of the dilator 2 after expansion, a depression will be formed, resulting in insufficient expansion of the blood vessel in that area and residual stenosis.

[0045] Meanwhile, the restraint ring 32 is fixed to the outer periphery of the catheter body 1 via the connecting rod 321, forming a dual positioning structure of "internal fixation + external reinforcement," further locking the axial position of the pressure membrane 31 and the restraint ring 32 to prevent displacement during the expansion of the dilator 2. In addition, since the restraint ring 32 is located on the inner surface of the dilator 2 and does not directly contact the blood vessel, it can ensure that it does not contact the vascular intima during expansion, thus preventing frictional damage.

[0046] It should be noted that the expander 2 is a memory-structured elastic balloon. Before leaving the factory, it undergoes a "pre-forming process." During production, the balloon is first inflated to the designed diameter, then deflated and shrunk. At this point, the balloon naturally forms "axial folds" rather than completely collapsing radially. In this folded state, although the shrunk diameter of the balloon is much smaller than the expansion diameter, it still maintains a tapered basic profile of "thin tip and thick rear end" and will not completely adhere to the catheter.

[0047] Therefore, the restraint ring 32 is not installed by looping it onto the fully contracted dilator 2, but by fixing it in the pre-formed (semi-dilated) state of the balloon, ensuring that it fits snugly against the folds when not inflated. At this time, the rigidity of the restraint ring 32 is much higher than that of the balloon material and will not deform with the balloon folds. The folds of the balloon will naturally fold around the restraint ring 32, and the outer surface of the restraint ring 32 will be "wrapped" by the adjacent folds and will be basically flush with the peak height of the folds, without forming obvious protrusions. This ensures that the restraint ring 32 will not scrape the blood vessel wall due to protrusion when not inflated.

[0048] like Figure 1 As shown, the outer periphery of the expansion member 2 is provided with scoring wires 26.

[0049] Specifically, the scoring wire 26 is a filamentous structure fixed to the outer surface of the dilator 2, and its extension direction is at a certain angle to the axis of the dilator 2, which is used to enhance the tearing effect on the stenotic tissue during dilation. The range of scoring wire 26 can be selected according to the high incidence of stenosis: if it is for anastomotic and venous segment stenosis, scoring wire 26 can be set only in the middle section 22 and the rear section 23 of the dilator 2; If it is necessary to adapt to stenosis of the entire segment (such as long-segment venous stenosis), a notched wire 26 can be set throughout the anterior segment 21, the middle segment 22 and the posterior segment 23.

[0050] like Figure 1 As shown, the scoring wires 26 are spirally distributed on the outer periphery of the expansion member 2.

[0051] Specifically, the spiral distribution design of the scoring wire 26 has the following advantages compared to the straight scoring wire 26: 1. The spiral-shaped scoring wire 26 has a smaller contact area with narrow tissues, resulting in higher local pressure under the same expansion force, making it easier to tear hard proliferating endometrium and fibrous tissue.

[0052] 2. The spiral distribution can achieve 360° circumferential tearing, ensuring that the stenotic tissue expands evenly along the circumference of the blood vessel, avoiding the problem of insufficient local tearing that exists with the linear scoring wire 26, and reducing the postoperative residual stenosis rate.

[0053] 3. During the step-by-step expansion process of the expander 2, the spiral structure ensures that the scoring wires 26 can form a continuous contact line with the narrow tissue regardless of which segment is expanded, thus continuously exerting a tearing effect and improving expansion efficiency.

[0054] like Figure 7 As shown, the filling component 4 includes a filling element 41 and a filling tube 42, with the filling tube 42 connecting the filling element 41 and the expansion element 2.

[0055] Specifically, the filler 41 is an electric filling device (such as an injection pump) located at the proximal end of the catheter body 1. It has a chamber for containing filler (such as contrast agent) inside and a pressure adjustment knob and pressure display on the outside to control the injection speed and pressure of the filler and to display the current pressure value in real time, so that the operator can make precise adjustments according to the needs of the operation.

[0056] The filling tube 42 is a flexible tubular structure. One end of it is sealed to the output port of the filling member 41, and the other end extends axially along the catheter body 1, penetrating the internal channel of the catheter body 1, and finally communicating with the front end space 211 of the expansion member 2. The wall of the filling tube 42 is a sealed structure and is not connected to the internal channel of the catheter body 1 to avoid leakage of the filling agent.

[0057] like Figure 3 and Figure 7 As shown, the filling tube 42 is connected to the front end space 211.

[0058] Specifically, the distal outlet of the filling tube 42 is located in the proximal region of the front end space 211 (near the connection between the catheter body 1 and the dilator 2). The purpose of this design is to ensure that the filler is first filled into the front end space 211 to achieve separate expansion of the front end segment 21.

[0059] Because the front segment 21 has the smallest diameter and is adapted to the arterial segment, dilating the front segment 21 first guides the dilator 2 to pass smoothly through the narrowed area, while simultaneously performing preliminary dilation of the arterial segment, laying the foundation for the subsequent dilation of the middle segment 22 and the rear segment 23. If the filling tube 42 is connected to the middle segment space 221 or the rear segment space 231, the larger diameter segment will dilate first, failing to pass through the narrowed area, and may directly damage the arterial segment. In addition, the connection between the filling tube 42 and the front segment space 211 is a sealed connection, ensuring no leakage during filler injection. All filler is used for pressurized dilation of the front segment space 211 until the pressure reaches the rupture pressure of the pressure membrane 31 between the front segment 21 and the middle segment 22, at which point the filler will enter the subsequent receiving space.

[0060] Furthermore, the catheter body 1 has two independent channels along the axial direction inside: a guidewire channel 13 for the guidewire to pass through and a filling channel 14 for the filling tube 42 to pass through. The distal end of the filling channel 14 is sealed and connected to the front end space 211 where the front end section 21 is located. The filling tube 42 can pass through the filling channel 14 to dock with the front end space 211, ensuring the sealing and stability of the filling agent delivery path.

[0061] The end of the catheter body 1 is divided into two branches, namely the first branch 11 and the second branch 12. The guidewire channel 13 and the filling channel 14 are located independently in the two branches to avoid mutual interference. Among them, the first branch 11, where the guidewire channel 13 is located, is coaxially arranged with the catheter body 1, so that the guidewire channel 13 forms a straight channel structure without any bends. This design can reduce the resistance when the guidewire passes through, ensure that the guidewire can pass smoothly through the catheter body 1, accurately guide the catheter to the narrow area, and at the same time reduce the wear of the guidewire on the inner wall of the channel.

[0062] There is a certain angle between the second branch 12 where the filling channel 14 is located and the catheter body 1, and the angle range is set to 30-45°. This angle design can avoid structural interference between the filling tube 42 and the guide wire channel 13, and at the same time ensure that the filler can flow smoothly into the front end space 211 along the channel when injected, without stagnation or dead flow.

[0063] In summary, the tapered design of the expansion member 2 in this application makes it easier to pass through narrow locations. Its front end segment 21 has a smaller diameter, which can accurately fit the arterial segment of the blood vessel. The middle segment 22 covers the anastomosis area, and the rear end segment 23 fits the venous segment of the blood vessel, thus avoiding the problem of mismatch between the diameter expansion member 2 and the blood vessel diameter.

[0064] The segmented and step-by-step expansion structure of the pressure control component 3 enables a single catheter body 1 to integrate expansion functions from small to medium to large, eliminating the need for multiple replacements of the expansion component 2, reducing consumable usage, and lowering medical costs; at the same time, it avoids repeated withdrawal and insertion of the catheter body 1, shortening the operation time and reducing operation-related risks such as guidewire displacement and thrombus dislodgement.

[0065] The spirally distributed scoring filaments 26 can achieve 360° circumferential tearing of the proliferating inner membrane, enhancing the expansion effect.

[0066] The coordinated design of the restraint ring 32 and the pressure membrane 31 not only ensures the independent sealing of each containment space, but also locks the expansion diameter of each section of the expansion member 2, enhancing the structural stability during the expansion process and reducing slippage.

[0067] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0068] It should be noted that this invention uses a tapered dilation catheter for stenosis of an artificial arteriovenous fistula as an example to introduce the specific structure and working principle of the invention. However, the application of this invention is not limited to a tapered dilation catheter for stenosis of an artificial arteriovenous fistula, and can also be applied to the production and use of other similar products.

[0069] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A tapered dilation catheter for stenosis of an artificial arteriovenous fistula, characterized in that, include: Catheter body; An expansion member is disposed on the outer periphery of the catheter body, and the expansion member is tapered in shape. Multiple pressure control components are provided, and the multiple pressure control components are spaced apart on the expansion member. The multiple pressure control components divide the interior of the expansion member into multiple receiving spaces. The pressure control components are used to control the connection between two adjacent receiving spaces. A filling component, connected to the expansion member, is used to fill the expansion member with a filler.

2. The tapered dilation catheter for stenosis of an artificial arteriovenous fistula according to claim 1, characterized in that, The expansion member includes a front section, a middle section, and a rear section, with the diameters of the front section, the middle section, and the rear section increasing sequentially. A front space is formed within the front section, a middle space is formed within the middle section, and a rear space is formed within the rear section. Two pressure control components are provided, one between the front end section and the other between the middle section and the other between the middle section and the rear end section.

3. A tapered dilation catheter for stenosis of an artificial arteriovenous fistula according to claim 2, characterized in that, A first transition arc is provided between the front end segment and the middle segment, and a second transition arc is provided between the middle segment and the rear end segment.

4. A tapered dilation catheter for stenosis of an artificial arteriovenous fistula according to claim 2, characterized in that, The pressure control component includes a pressure membrane disposed between the front end segment and the middle segment or between the middle segment and the rear end segment. The pressure membrane is used to isolate the front end space from the middle segment space or to isolate the middle segment space from the rear end space.

5. A tapered dilation catheter for stenosis of an artificial arteriovenous fistula according to claim 4, characterized in that, The pressure control assembly includes a restraint ring disposed on the outside of the pressure diaphragm.

6. A tapered dilation catheter for stenosis of an artificial arteriovenous fistula according to claim 5, characterized in that, The restraining ring is coaxially arranged with the pressure diaphragm, and the outer diameter of the restraining ring is consistent with the outer diameter of the expansion member after expansion at the corresponding position.

7. A tapered dilation catheter for stenosis of an artificial arteriovenous fistula according to claim 1, characterized in that, The expansion member has serrated wires on its outer periphery.

8. A tapered dilation catheter for stenosis of an artificial arteriovenous fistula according to claim 7, characterized in that, The scoring wires are spirally distributed around the outer periphery of the expander.

9. A tapered dilation catheter for stenosis of an artificial arteriovenous fistula according to claim 2, characterized in that, The filling assembly includes a filler and a filling tube, the filling tube connecting the filler and the expansion member.

10. A tapered dilation catheter for stenosis of an artificial arteriovenous fistula according to claim 9, characterized in that, The filling tube is connected to the front end space.

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