Balloon dilatation catheter

Abstract

The invention provides a balloon dilatation catheter, and belongs to the technical field of balloon dilatation catheters. The balloon dilatation catheter comprises a catheter body, the far end of the catheter body is provided with a balloon body used for dilating a narrow part, and the near end of the catheter body is provided with an operating handle used for charging and discharging a filling medium into the balloon body. A flow channel allowing blood to penetrate through is formed in the balloon body and / or between the balloon body and the outer side wall of the catheter body in the axial extending direction of the catheter body, in the working process, after the balloon body is filled, a narrow part is treated, and the blood in the narrow part penetrates through the flow channel to continue to be circulated. The balloon is mainly used for solving the technical problems that in the prior art, when a balloon dilates, blood flow is blocked, consequently, far-end blood supply is insufficient, and the drug transfer effect is affected due to insufficient contact time of the balloon and the blood vessel wall.

Description

Technical Field

[0001] The present invention belongs to the technical field of balloon dilation catheters, and particularly relates to a balloon dilation catheter. Background Art

[0002] Balloon dilation catheters are widely used in angioplasty for treating intravascular stenosis. Generally, they are composed of parts such as a balloon, a catheter, and a catheter hub. The balloon is usually made of a polymer material and has good elasticity and pressure resistance; the catheter shaft is used to deliver the balloon to the lesion site and usually has a certain flexibility and rigidity to ensure smooth delivery in blood vessels or other lumens; the catheter hub is used to connect a syringe or other pressure device to inject liquid or gas into the balloon.

[0003] The working principle of a balloon dilation catheter is to insert the balloon dilation catheter into the stenotic part of the human blood vessel through interventional techniques, and then inject a certain amount of liquid or gas into the balloon to make the balloon expand. The expansion force of the balloon is used to expand the stenotic lumen, so as to achieve the purpose of enlarging the lumen diameter and improving the lumen patency.

[0004] In order to avoid restenosis of the blood vessel after the balloon is withdrawn, drugs such as paclitaxel and rapamycin that can treat vascular stenosis and inhibit restenosis can also be sprayed on the surface of the balloon, or corresponding therapeutic drugs can be sprayed on the surface according to the actual use of the balloon, so that the drug can be released onto the blood vessel wall in contact with it during balloon dilation to achieve the corresponding therapeutic purpose.

[0005] For the balloon of the existing balloon dilation catheter, after inflation, it is usually frustum-shaped at both ends and cylindrical in the straight section. When the balloon expands and dilates the blood vessel, the straight section of the balloon is in full contact with the blood vessel wall at the stenotic lesion. At this time, the blood flow in the blood vessel is completely blocked. After the dilation is completed and the balloon deflates, the blood in the blood vessel resumes flowing. If the blood flow blockage time is too long, it will lead to insufficient blood supply to the distal blood vessel, and then cause clinical manifestations such as dizziness, nausea, vomiting, and confusion, as well as damage to distal tissues such as the brain, and may even cause the death of the patient in severe cases. However, if the support time of the balloon during blood vessel dilation is too short, especially when the stenosis degree is relatively severe and there are abnormal characteristics such as calcification at the stenotic lesion, the treatment effect is not ideal, that is, the operation cannot be performed according to the ideal dilation time, and thus the ideal expected dilation effect cannot be achieved; in addition, the drugs sprayed on the surface of the balloon of the existing balloon dilation catheter will also result in insufficient contact time between the balloon and the blood vessel wall due to the inability to completely block the blood flow for a long time, so that the drug cannot be fully transferred to the blood vessel wall, and the treatment effect is greatly reduced.

[0006] Therefore, an improved technical solution is needed to address the deficiencies of the above existing technologies. Summary of the Invention

[0007] The object of the present invention is to provide a balloon dilation catheter to solve the technical problems in the prior art that blood flow is blocked during balloon dilation, resulting in insufficient blood supply to the distal end, and the contact time between the balloon and the blood vessel wall is insufficient, affecting the drug transfer effect.

[0008] To achieve the above object, the balloon dilation catheter of the present invention provides the following technical solutions:

[0009] A balloon dilation catheter includes a catheter body. A balloon body for dilating a stenotic site is provided at the distal end of the catheter body, and an operation handle for filling and discharging a filling medium into the balloon body is provided at the proximal end. A flow channel for blood flow to pass through is formed along the axial extension direction of the catheter body on the balloon body and / or between the balloon body and the outer wall of the catheter body. During operation, after the balloon body is filled, the stenotic site is treated, and the blood flow at the stenotic site passes through the flow channel and continues to flow.

[0010] As a further optimized technical solution, the balloon body is in a circular ring structure, the circular ring structure is sleeved outside the catheter body, and the gap between the inner side wall of the circular ring structure and the outer wall of the catheter body constitutes the flow channel.

[0011] As a further optimized technical solution, at least one group of support channels for filling the balloon body is arranged axially between the balloon body and the catheter body. Each group of support channels includes a plurality of channel segments arranged at intervals along the circumferential direction of the catheter body, and each of the channel segments communicates with a medium channel on the catheter body for the filling medium to flow through.

[0012] As a further optimized technical solution, the balloon body further includes a diversion cavity, the diversion cavity is arranged outside the catheter body, and the gap between the inner side wall of the circular ring structure and the outer side wall of the diversion cavity constitutes the flow channel.

[0013] As a further optimized technical solution, the balloon body is a plurality of circular ring structures arranged coaxially at intervals. The innermost circular ring structure is sleeved outside the catheter body, and the gaps between any two adjacent circular ring structures and the gap between the inner side wall of the innermost circular ring structure and the outer wall of the catheter body form the flow channel.

[0014] As a further optimized technical solution, at least one group of support channels for filling the balloon body is arranged axially between the balloon body and the catheter body and between adjacent circular ring structures. Each group of support channels includes a plurality of channel segments arranged at intervals along the circumferential direction of the catheter body, and each of the channel segments communicates with a medium channel on the catheter body for the filling medium to flow through.

[0015] As a further optimized technical solution, the catheter body includes at least an outer protective layer and an inner guiding layer, and the medium channel is arranged between the outer protective layer and the inner guiding layer.

[0016] As a further optimized technical solution, the number of channel segments in each of the support channels is the same.

[0017] As a further optimized technical solution, the channel segments in each of the support channels are arranged axially aligned.

[0018] As a further optimized technical solution, a quick exchange port is provided on the catheter body.

[0019] Beneficial effects: In the present invention, a flow channel for blood to pass through is formed between the balloon body and the outer side wall of the catheter body and / or on the balloon body along the axial extension direction of the catheter body. During the treatment of the stenotic part during the operation, after the balloon body is expanded, the blood flow in the stenotic part flows normally through the flow channel, and the situation of blood flow blockage will no longer occur. Thus, the limitation in terms of the dilation time of the existing balloon catheter is eliminated, which is beneficial to achieving a more ideal treatment effect, and can effectively avoid various abnormal symptoms caused by the blockage of blood flow when the balloon body is filled, reduce the risk during the clinical operation, significantly improve the overall safety of the operation, and provide a more reliable guarantee for the life and health of patients. Description of the Drawings

[0020] The specification drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. Among them:

[0021] Figure 1 It is a schematic diagram of the overall structure of the balloon dilation catheter according to Embodiment 1 of the present invention and the cross-section of the catheter body;

[0022] Figure 2 It is a three-dimensional structure diagram of the balloon body of the balloon dilation catheter according to Embodiment 1 of the present invention;

[0023] Figure 3 It is a schematic diagram of one end face structure of the balloon body of the balloon dilation catheter according to Embodiment 1 of the present invention;

[0024] Figure 4 It is a schematic diagram of the perforation on the catheter body of the balloon dilation catheter according to Embodiment 1 of the present invention;

[0025] Figure 5 It is a schematic diagram of the structure in which the channel segments connect the catheter body and the balloon body of the balloon dilation catheter according to Embodiment 1 of the present invention;

[0026] Figure 6 It is a three-dimensional structure diagram of the balloon body of the balloon dilation catheter according to Embodiment 2 of the present invention;

[0027] Figure 7 It is a schematic diagram of one end face structure of the balloon body of the balloon dilation catheter according to Embodiment 2 of the present invention;

[0028] Figure 8 Schematic diagram of the three-dimensional structure of the balloon body of Example 3 of the balloon dilation catheter of the present invention;

[0029] Figure 9 Schematic diagram of one end face structure of the balloon body of Example 4 of the balloon dilation catheter of the present invention;

[0030] Figure 10 Schematic diagram of the three-dimensional structure of the balloon body of Example 6 of the balloon dilation catheter of the present invention;

[0031] Figure 11 Schematic diagram of one end face structure of the balloon body of Example 7 of the balloon dilation catheter of the present invention;

[0032] Figure 12 Schematic diagram of the overall structure and cross-sectional view of the catheter body of Example 8 of the balloon dilation catheter of the present invention.

[0033] In the figure: 1. Catheter body; 101. Medium channel; 102. Outer protective layer; 103. Inner guiding layer; 104. Quick exchange port; 105. Perforation; 106. Tip; 2. Balloon body; 201. Flow guiding cavity; 3. Operating handle; 4. Flow channel; 5. Channel split body. Specific embodiments

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present invention.

[0035] In the description of the present invention, the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention rather than requiring the present invention to be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present invention. The terms "connected" and "coupled" used in the present invention should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection; it can be directly connected or indirectly connected through an intermediate component. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances. In addition, the term "proximal" uniformly refers to the end close to the operator, and "distal" refers to the end far from the operator.

[0036] The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments. It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0037] The shapes and sizes of the components in the drawings do not reflect the true proportions of the product, and the purpose is only to schematically illustrate the content of the present invention.

[0038] The present invention provides a balloon dilation catheter, and a blood flow passage 4 for blood to pass through is formed between the outer side wall of the balloon body 2 and the catheter body 1 and / or along the axial extension direction of the catheter on the balloon body. In this way, when the balloon body 2 is inflated to treat the stenotic site, the blood flow at the stenotic site can pass through the blood flow passage 4 and continue to circulate, effectively avoiding the problem of insufficient blood supply to the distal blood vessels caused by too long blood flow interruption time. At the same time, the balloon body 2 can be in contact with the blood vessel wall for a long time as needed to ensure that the therapeutic drug sprayed on the outer side of the balloon body 2 can be fully transferred to the blood vessel wall, enhancing the therapeutic effect. For specific implementation manners, please refer to the following embodiments.

[0039] Embodiment 1

[0040] As Figure 1 、 Figure 2 、 Figure 3 shown, the balloon dilation catheter includes a catheter body 1, a balloon body 2 and an operating handle 3.

[0041] The distal end of the catheter body 1 has an integrally provided tip 106. The tip 106 is in an elongated shape and can guide the catheter body 1 in the blood vessel. It can guide the catheter body 1 to accurately move forward along the blood vessel direction, helping the doctor to more precisely send the balloon body 2 to the target stenotic site, avoiding the catheter body 1 blindly moving in the blood vessel, reducing unnecessary touch and damage to the blood vessel wall, and improving the accuracy and efficiency of the surgical operation.

[0042] The tube body of the catheter body 1 includes an outer protective layer 102 and an inner guiding layer 103. The outer protective layer 102 is usually processed from one or more of nylon, polyethylene, polytetrafluoroethylene, and polyurethane materials, which can effectively prevent the catheter body 1 from being corroded by substances in the blood vessel and extend the service life of the catheter body 1. At the same time, the surface of the outer protective layer 102 is usually coated with a hydrophilic coating to improve the passageability of the catheter body 1 in the blood vessel and reduce damage to the blood vessel. The inner guiding layer 103 is usually selected from one or more of polyethylene, nylon, and polytetrafluoroethylene for processing. Its inner surface is smooth to guide other surgical operation instruments such as guide wires to pass through the catheter body 1 and be accurately guided in the blood vessel. In other embodiments, a support layer woven with metal wires can also be provided between the outer protective layer 102 and the inner guiding layer 103 to ensure the shape stability of the catheter body 1. There is a gap between the outer protective layer 102 and the inner guiding layer 103, and this gap is a medium passage 101 for the filling medium for inflating the balloon body 2 to pass through. The distal end of the medium passage 101 extends to not exceed the distal end of the balloon body 2. Therefore, the distal end of the outer protective layer 102 extends to not exceed the distal end of the balloon body 2, so that the diameter size of the distal end of the catheter body 1 is smaller and it is more convenient to move forward to the distal end of the blood vessel.

[0043] The operating handle 3 is arranged at the proximal end of the catheter body 1, and its main function is to connect the medium charging and discharging equipment such as syringes and pressure pumps. Before the operation begins, the doctor injects the filling medium, such as saline, contrast agent, etc., into the balloon body 2 through the operating handle 3. Taking saline as an example, the doctor pushes the syringe piston connected to the operating handle 3, so that the saline flows into the balloon body 2 along the medium channel 101 in the catheter body 1, prompting the balloon body 2 to gradually fill and expand, and stretch the narrow part of the blood vessel. After the operation is completed, the doctor reverses the operating handle 3 to extract the filling medium in the balloon body 2, so that the balloon body 2 retracts, and the catheter is smoothly withdrawn from the blood vessel.

[0044] The balloon body 2 is arranged at the distal end of the catheter body 1 and is used to dilate the narrow part in the blood vessel. In this embodiment, the balloon body 2 is a ring structure, which is sleeved on the outside of the catheter body 1. A group of support channels for filling the balloon body 2 are arranged axially between the balloon body 2 and the catheter body 1. The support channel includes three channel segments 5 arranged evenly spaced along the circumference of the catheter body 1. One end of each channel segment 5 passes through the perforation 105 on the outer protective layer 102 (for details, please refer to Figure 4 , Figure 5 ) is directly connected to the medium channel 101 on the catheter body 1 for the filling medium to flow, and the other end is connected to the annular balloon body 2. In this way, the gap between the inner side wall of the annular structure and the outer side wall of the catheter body 1 extending along the axial direction of the catheter body 1 constitutes a flow channel 4 for blood flow to pass through.

[0045] Furthermore, a hydrophilic coating is provided on the outside of the balloon body 2 to improve the permeability of the balloon body 2 in the blood vessel and reduce damage to the blood vessel.

[0046] During the operation, the doctor inserts the balloon dilatation catheter into the narrowed part of the blood vessel through the peripheral blood vessels through interventional technology. The contrast agent is injected into the balloon body 2 as a filling medium through the operating handle 3, and the balloon body 2 gradually fills and expands to open the narrow blood vessel. At this time, the blood flow in the blood vessel can continue to circulate through the flow channel 4 between the balloon body 2 and the outer wall of the catheter body 1 to ensure the blood supply to the distal tissue of the blood vessel. With the existence of the flow channel 4, the blood supply to the distal tissue will no longer be affected by the treatment time. Even if it is to ensure that the drug outside the balloon body 2 is fully absorbed, the support time of the balloon body 2 is appropriately extended, which will not cause adverse effects on the patient, thereby improving the treatment effect and safety of the operation. After the operation, the doctor extracts the contrast agent in the balloon body 2 through the operating handle 3, causing the balloon body 2 to retract, and then withdraws the balloon dilatation catheter from the body.

[0047] Example 2

[0048] like Figure 6 , Figure 7As shown in the figure, the catheter body 1 of this embodiment is basically the same as that of Embodiment 1 in terms of structure and material, but there are differences in the design of the balloon body 2. In this embodiment, the balloon body 2 not only includes a circular ring structure sleeved outside the catheter body 1, but also includes a diversion cavity 201. The diversion cavity 201 is in the shape of a thin-walled cylinder and is closely attached to the outside of the catheter body 1. The diversion cavity 201 is communicated with the medium channel 101 on the catheter body 1. The channel split body 5 is indirectly communicated with the catheter body 1 through the diversion cavity 201. In this way, when the balloon body 2 is filled, the filling medium in the medium channel 101 first flows into the diversion cavity 201 through the perforations 105 on the outer protective layer 102, and then flows from the diversion cavity 201 into the channel split body 5, and finally reaches the circular ring structure outside the balloon body 2.

[0049] In this embodiment, the gap extending along the axial direction of the catheter body 1 between the outer side wall of the diversion cavity 201 of the balloon body 2 and the inner side wall of the circular ring structure forms a flow channel 4 for blood flow to pass through.

[0050] During the operation, when the balloon dilation catheter reaches the stenosis site, the doctor fills the balloon body 2 through the operating handle 3. Due to the existence of the diversion cavity 201, the blood flow can pass through the flow channel 4 more smoothly.

[0051] Embodiment 3

[0052] As Figure 8 shown, the catheter body 1 of this embodiment is basically the same as that of Embodiment 1 in terms of structure and material, and there are still differences in the design of the balloon body 2. At the same time, there are also differences in the selection of the number of support channels. In this embodiment, the balloon body 2 is two circular ring structures arranged coaxially at intervals. The innermost circular ring structure is sleeved outside the catheter body 1. Two groups of support channels for filling the balloon body 2 are arranged axially between the balloon body 2 and the catheter body 1 and between adjacent circular ring structures. Each group of support channels includes three channel split bodies 5 arranged at intervals along the circumferential direction of the catheter body 1. Each channel split body 5 is directly communicated with the medium channel 101 for the filling medium to flow on the catheter body 1. In this way, the gap between adjacent two circular ring structures and the gap between the inner side wall of the innermost circular ring structure and the outer side wall of the catheter body 1 form a flow channel 4 extending along the axial direction of the catheter body 1, and this flow channel 4 is used for blood flow to pass through.

[0053] During the operation, when the balloon dilation catheter reaches the stenosis site, the doctor fills the balloon body 2 through the operating handle 3. The outer side wall of the outermost circular ring structure of the filled balloon body 2 supports the stenosis site in the blood vessel, and the blood flow passes through the flow channel 4 on the balloon body 2 and between the balloon body 2 and the outer side wall of the catheter body 1, and the situation of blocking the blood flow will not occur.

[0054] Embodiment 4

[0055] AsFigure 9 As shown in the figure, the catheter body 1 of this embodiment is basically the same as that of Embodiment 3 in terms of structure and material, except that the design of the balloon body 2 is different from that of Embodiment 3. In this embodiment, the balloon body 2 not only includes two ring structures sleeved outside the catheter body 1, but also includes a diversion cavity 201. The diversion cavity 201 is in the shape of a thin-walled cylinder and is closely attached to the outside of the catheter body 1. The diversion cavity 201 communicates with the medium channel 101 on the catheter body 1, and the channel branch 5 is indirectly connected to the catheter body 1 through the diversion cavity 201. In this way, when the balloon body 2 is filled, the filling medium in the medium channel 101 first flows into the diversion cavity 201 through the perforations 105 on the outer protective layer 102, and then flows from the diversion cavity 201 into the channel branch 5, and finally reaches all the ring structures of the balloon body 2.

[0056] During the operation, when the balloon dilation catheter reaches the stenosis site, the doctor fills the balloon body 2 through the operation handle 3. The outer wall of the outermost ring structure of the balloon body 2 supports the stenosis site in the blood vessel, and the blood flow passes through the flow channel 4 on the balloon body 2, and the blood flow will not be blocked.

[0057] Embodiment 5

[0058] The catheter body 1 of this embodiment is basically the same as that of Embodiment 3 in terms of structure and material, except that the design of the balloon body 2 is different from that of Embodiment 3. In this embodiment, the balloon body 2 is three ring structures arranged coaxially at intervals. The innermost ring structure is sleeved outside the catheter body 1. Between the innermost ring structure of the balloon body 2 and the catheter body 1 and between any two adjacent ring structures, three groups of support channels for filling the balloon body 2 are arranged along the axial direction. Each group of support channels includes three channel branches 5 arranged at intervals along the circumferential direction of the catheter body 1. One end of each channel branch 5 facing the catheter body 1 is directly connected to the medium channel 101 on the catheter body 1 for the filling medium to flow. In this way, the gaps between any two adjacent ring structures and the gap between the inner wall of the innermost ring structure and the outer wall of the catheter body 1 form a flow channel 4 extending along the axial direction of the catheter body 1, and this flow channel 4 is used for the blood flow to pass through.

[0059] Furthermore, in other embodiments, the number of ring structures can also be more than three.

[0060] During the operation, when the balloon dilation catheter reaches the stenosis site, the doctor fills the balloon body 2 through the operation handle 3. The outer wall of the outermost ring structure of the balloon body 2 supports the stenosis site in the blood vessel, and the blood flow passes through the flow channels on the balloon body 2 and between the balloon body 2 and the outer wall of the catheter body 1, and the blood flow will not be blocked.

[0061] Embodiment 6

[0062] AsFigure 10 As shown, the catheter body 1 and the balloon body 2 in this embodiment are basically the same in structure and material as those in Embodiment 1, but there are differences in the design of the number of support channels. In this embodiment, three groups of support channels for filling the balloon body 2 are axially arranged between the balloon body 2 and the catheter body 1. The support channels include five channel segments 5 arranged at intervals along the circumferential direction of the catheter body 1. One end of each channel segment 5 is directly connected to the medium channel 101 for the filling medium to flow through on the catheter body 1 through the perforation 105 on the outer protective layer 102, and the other end is connected to the balloon body 2 with a circular ring structure. That is, the number of channel segments 5 in each group of support channels is the same, which can ensure the uniformity and stability of the filling of the balloon body 2.

[0063] Furthermore, in order to make the blood flow smoothly in the flow channel 4, the channel segments 5 in each group of support channels are arranged axially aligned. In other embodiments, the number of channel segments 5 in each group of support channels may be different and / or the channel segments 5 in each group of support channels are not axially aligned.

[0064] Embodiment 7

[0065] As Figure 11 shown, the catheter body 1 and the balloon body 2 in this embodiment are basically the same in structure and material as those in Embodiment 2, but there are differences in the design of the number of support channels. In this embodiment, each group of support channels includes two channel segments 5 arranged at intervals along the circumferential direction of the catheter body 1. The channel segments 5 are indirectly connected to the catheter body 1 through the diversion cavity 201. In this way, when filling the balloon body 2, the filling medium in the medium channel 101 first flows into the diversion cavity 201 through the perforation 105 on the outer protective layer 102, and then flows into the channel segments 5 from the diversion cavity 201, and finally reaches the circular ring structure outside the balloon body 2.

[0066] Embodiment 8

[0067] As Figure 12 shown, the balloon body 2 in this embodiment can be basically the same in structure and material as the balloon body 2 in any one of the above embodiments, and the difference lies in the different structure of the catheter body 1. In this embodiment, a quick exchange port 104 is provided on the catheter body 1. It is convenient to quickly replace the instruments or media in the catheter during the operation, improving the operation efficiency. For example, if a guide wire needs to be replaced during the operation, the doctor can conveniently complete the operation through the quick exchange port 104.

[0068] During the operation, when the balloon dilation catheter reaches the stenosis site, the doctor fills the balloon body 2 through the operation handle 3. Due to the existence of the diversion cavity 201, the blood flow can pass through the flow channel 4 more smoothly. If instruments or media need to be replaced during the operation, the doctor can conveniently complete the operation through the quick exchange port 104, and the whole operation process is more efficient and smooth.

[0069] It can be understood that the above description is only exemplary, and the embodiments of the present application do not limit this.

[0070] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A balloon dilatation catheter, characterized in that: The invention comprises a catheter body (1), wherein a balloon body (2) for dilating a stenotic site is arranged at the distal end of the catheter body (1), and an operating handle (3) for filling or releasing a filling medium into the balloon body (2) is arranged at the proximal end. A flow channel (4) for blood flow to pass through is formed on the balloon body (2) and / or between the balloon body (2) and the outer side wall of the catheter body (1) along the axial extension direction of the catheter body (1). When in operation, the balloon body (2) is filled to treat the stenotic site, and the blood flow in the stenotic site continues to flow through the flow channel (4).

2. The balloon dilatation catheter according to claim 1, characterized in that: The balloon body (2) is a circular ring structure, which is sleeved on the outside of the catheter body (1), and the gap between the inner wall of the circular ring structure and the outer wall of the catheter body (1) constitutes the flow channel (4).

3. The balloon dilatation catheter according to claim 2, characterized in that: At least one group of supporting channels for filling the balloon body (2) is axially arranged between the balloon body (2) and the catheter body (1), each group of supporting channels comprises a plurality of channel segments (5) arranged at intervals along the circumference of the catheter body (1), and each of the channel segments (5) is connected to a medium channel (101) on the catheter body (1) for supplying a filling medium to flow.

4. The balloon dilatation catheter according to claim 3, characterized in that: The balloon body (2) further comprises a flow guiding cavity (201), wherein the flow guiding cavity (201) is arranged outside the catheter body (1), and the gap between the inner wall of the annular structure and the outer wall of the flow guiding cavity (201) constitutes the flow channel (4).

5. The balloon dilatation catheter according to claim 1, characterized in that: The balloon body (2) is a plurality of spaced and coaxially arranged circular ring structures, the innermost circular ring structure being sleeved on the outside of the catheter body (1), and the gap between any two adjacent circular ring structures and the gap between the inner side wall of the innermost circular ring structure and the outer side wall of the catheter body (1) forming the flow channel (4).

6. The balloon dilatation catheter according to claim 5, characterized in that: At least one group of supporting channels for filling the balloon body (2) is axially arranged between the balloon body (2) and the catheter body (1) and between adjacent annular structures, each group of supporting channels comprises a plurality of channel segments (5) arranged at intervals along the circumference of the catheter body (1), and each of the channel segments (5) is connected to a medium channel (101) on the catheter body (1) for supplying a filling medium to flow.

7. The balloon dilatation catheter according to any one of claims 3 or 6, characterized in that: The catheter body (1) comprises at least an outer protective layer (102) and an inner guide layer (103), and the medium channel (101) is arranged between the outer protective layer (102) and the inner guide layer (103).

8. The balloon dilatation catheter according to claim 3 or 6, characterized in that: The number of channel segments (5) in each group of the supporting channels is the same.

9. The balloon dilatation catheter according to claim 8, characterized in that: The channel segments (5) in each group of the supporting channels are arranged in an axially aligned manner.

10. The balloon dilatation catheter according to any one of claims 1 to 6, characterized in that: The catheter body (1) is provided with a quick exchange port (104).

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