Balloon dilatation catheter

Abstract

The invention relates to a balloon dilatation catheter, and belongs to the field of medical instruments. The balloon dilatation catheter comprises a balloon body, wherein at least part of the outer side of the balloon body is coated with a medicine coating; the catheter is arranged in the balloon body in a penetrating manner; the hollow structure is arranged outside the balloon body, the hollow structure is in a first state when the balloon body is in a folded state, and the hollow structure is in a second state when the balloon body is in an expanded state; in the first state, the coverage rate of the hollow structure within the axial length range of the balloon body is larger than 50%, and pressure larger than 0 is applied to the balloon body. By arranging the hollow structure which has high coverage rate in the first state (folded state) and has contraction pressure on the balloon body, medicine falling in the conveying process can be reduced, so that the loaded medicine is conveyed to the focus to the maximum extent, and the effective loading capacity of the medicine is improved.

Description

Technical Field

[0001] This invention belongs to the field of medical devices, specifically relating to a balloon dilation catheter. Background Technology

[0002] Vascular stenosis is caused by the deposition of plaque material, such as fat and calcium, within the lumen of a blood vessel (usually an artery), resulting in narrowing. Percutaneous transluminal angioplasty (PTA) is the procedure of inserting a flexible catheter into the artery and guiding it to the site of stenosis. A balloon is placed at the distal end of the catheter. When the catheter reaches the stenosis, the balloon at the distal end inflates, using the pressure from the balloon's expansion to force the plaque material against the arterial wall, thus opening the blood vessel and improving blood flow.

[0003] When treating vascular stenosis with a balloon catheter, the opened segment of the blood vessel may tend to return to its original diameter after dilation, which can easily cause restenosis of the blood vessel lumen and reduce blood flow. In addition, balloon inflation can damage the blood vessel wall, thereby causing smooth muscle hyperplasia and restenosis of the blood vessel lumen.

[0004] Drug-coated balloon (DCB) angioplasty is procedurally similar to conventional balloon angioplasty, but the balloon is coated with a drug that acts on plaque material or the vessel wall, such as an anti-proliferative drug. After delivery to the lesion site, the drug is released within a short inflation time (30-60 seconds) to inhibit the proliferation of vascular smooth muscle cells, thereby preventing restenosis. Because of the short inflation time of the drug-coated balloon, it is desirable for the drug-coated balloon to release the drug on its surface rapidly after inflating at the lesion site. However, the drug may be washed away by the blood during delivery, resulting in very little drug reaching the lesion site. While increasing the drug load can increase absorption, a large amount of excess drug flows distal to the vessel, affecting patient health. Therefore, how to ensure rapid drug release at the lesion site while minimizing drug shedding during delivery, thereby maximizing drug delivery to the lesion, is a technical problem that needs to be solved in this field.

[0005] Therefore, there is a need in the art to develop a balloon dilation catheter that can carry drugs with low drug loss during delivery and high effective drug quantity reaching the lesion. Summary of the Invention

[0006] To address the shortcomings of existing technologies, one objective of this invention is to provide a balloon dilation catheter, the balloon dilation catheter comprising:

[0007] A balloon body capable of switching between an expanded state and a folded state, wherein at least a portion of the outer side of the balloon body is coated with a drug-eluting coating;

[0008] A catheter is inserted inside the balloon body, and the balloon body is located at the distal end of the catheter;

[0009] A hollow structure is disposed on the outside of the balloon body, at least one of the proximal and distal ends of the hollow structure is fixed to the catheter, and the other end of the hollow structure is slidably disposed on the catheter. The proximal end of the hollow structure is close to the proximal side of the balloon body, and the distal end of the hollow structure is close to the distal side of the balloon body. The hollow structure is in a first state when the balloon body is folded, and in a second state when the balloon body is inflated.

[0010] In the first state, the hollow structure has a coverage of >50% within the axial length range of the balloon body and applies a pressure greater than 0 to the balloon body.

[0011] This application utilizes a perforated structure with high coverage on the exterior of the balloon body. This perforated structure applies pressure to the balloon body in its initial state and maintains this pressure throughout delivery. This secures the medication on the outer side of the balloon body within the perforated structure's coverage area, preventing drug detachment due to blood flow during delivery. Simultaneously, the perforated structure restricts the balloon's folding, preventing the folds from unraveling during delivery and further reducing drug coating loss in the covered area. This minimizes the risk of drug detachment before reaching the lesion. Furthermore, the perforated structure creates a gap between the outer wall of the balloon body and the blood vessel wall, maximizing drug retention even in exposed areas by avoiding friction between the balloon body and the vessel wall, further reducing the proportion of drug detachment before reaching the lesion. When the balloon dilation catheter reaches the lesion, the balloon dilates, the perforated structure is expanded by the balloon, and the perforated structure moves relative to the balloon body. The drug on the outside of the balloon body is exposed or scraped off from the balloon body, thereby realizing the release of the drug at the lesion.

[0012] That is, by setting a hollow structure that exerts contractile pressure on the balloon body, this application reduces drug detachment during delivery, thereby maximizing the delivery of the loaded drug to the lesion and increasing the effective drug load.

[0013] Preferably, from the first state to the second state, the coverage rate of the hollow structure within the axial length range of the balloon body changes by more than 60%.

[0014] In the second state, the smaller the coverage of the perforated structure, the larger the contact area between the balloon body and the blood vessel wall after inflation. This facilitates the transfer of drug from the surface of the balloon body to the blood vessel wall, thus enabling drug release. In other words, the greater the change in coverage of the perforated structure between the first and second states, the more firmly the drug on the outside of the balloon can adhere to the balloon during delivery, and the more fully the drug can be released after the balloon inflates.

[0015] Preferably, in the first state, the coverage of the hollow structure within the axial length range of the balloon body is ≥80%.

[0016] Under normal circumstances, in the first state, the higher the coverage of the hollow structure along the axial length of the balloon body, the higher the effective drug load (the amount of drug reaching the lesion).

[0017] In one specific embodiment, the proximal end of the hollow structure is limited to the proximal side of the balloon body; or the distal end of the hollow structure is limited to the distal side of the balloon body.

[0018] Limiting the proximal end of the perforated structure can improve its positional stability and reduce damage to the proximal end of the balloon body. The limited end of the perforated structure is the end of the balloon body that is slidably mounted on the catheter.

[0019] This application does not limit the method of achieving near-end limiting of the hollow structure. Those skilled in the art can choose a suitable limiting method according to the actual situation, such as any one or a combination of at least two of the limiting protrusions and traction lines.

[0020] Preferably, a limiting protrusion is provided on the proximal side of the balloon body, and the proximal end of the hollow structure is located on the proximal side of the limiting protrusion; or, a limiting protrusion is provided on the distal side of the balloon body, and the distal end of the hollow structure is located on the distal side of the limiting protrusion.

[0021] In an optional embodiment, the proximal end of the hollow structure is restricted to a position near the proximal (or distal) end of the balloon body at a distance L1, and the distal (or proximal) end of the hollow structure is fixedly positioned near the distal (or proximal) end of the balloon body at a distance L2, wherein the values ​​of L1 and L2 are similar (e.g., L1 = 0.9 to 1.1L2); preferably, the sum of L1 and L2 is 10% to 20% of the length of the balloon body.

[0022] The proximal (and / or distal) end of the hollow structure is at a certain distance from the balloon body, allowing the hollow structure to expand significantly in the section that fits the balloon body as it expands. The proximal (and / or distal) end, lacking the expansion effect of the balloon body and constrained by the limiting structure, exhibits a gradually contracting cone shape. This means the hollow structure expands unevenly along the axial direction, with a smaller hollow area in the portion not covering the balloon body and a larger hollow area in the portion covering the balloon body. This increases the difference in coverage between the first and second states, improving the balloon body's coverage in the first state to increase the effective drug load, and reducing the balloon body's coverage in the second state to increase the exposed area of ​​the balloon body and promote drug transfer and release.

[0023] It should be noted that having similar values ​​for L1 and L2 allows for more symmetrical expansion of the hollow structure within the length of the balloon body, more uniform distribution of the drug coating, and more controllable drug release.

[0024] In the configuration where the proximal end of the hollow structure is restricted to a position near the proximal (or distal) end of the balloon body at a distance L1, and the distal (or proximal) end of the hollow structure is fixedly positioned near the distal (or proximal) end of the balloon body at a position near the distal (or proximal) end of the balloon body at a distance L2, the hollow structure is preferably made of woven silk threads. During balloon body expansion, the intersection points of the woven silk thread hollow structure will shift towards both ends of the balloon body, thereby increasing the difference in coverage between the first and second states.

[0025] In the first state, the method by which the hollow structure provides pressure to the balloon body is not specifically limited, and can be any one or a combination of at least two of the following: a pre-designed structure, a traction wire, etc.

[0026] Preferably, the hollow structure has a pre-shaped structure or a traction wire at the proximal end, which is used to provide pressure on the balloon body by the hollow structure in the first state.

[0027] In one specific embodiment, the hollow structure is pre-shaped into a contracted state, and the inner diameter of the pre-shaped hollow structure is less than or equal to the outer diameter of the balloon body in the folded state.

[0028] In another specific embodiment, the traction wire extends to the proximal end of the catheter to control the transition of the hollow structure between a first state and a second state.

[0029] In one specific embodiment, the hollow structure is formed by axially extending pillars arranged side by side and then converging at both ends; or, the hollow structure is formed by at least one spiral pillar in the same direction winding around; or the hollow structure is formed by a diamond-shaped hollow mesh.

[0030] Preferably, the hollow structure is formed by laser engraving.

[0031] Preferably, the cross-sectional dimension of the support column of the hollow structure on the side closer to the balloon body is larger than the cross-sectional dimension on the side farther away from the balloon body.

[0032] The hollow structure's strut cross-section design ensures that, in the first state, the struts closer to the balloon body have a larger cross-sectional size, achieving high coverage of the balloon surface. In the second state, the struts farther from the balloon body have a smaller cross-sectional size. This allows the smaller cross-sectional size of the struts to reduce resistance from hard plaques embedded in the lesion site after the hollow structure expands synchronously with the balloon, thus releasing drugs more effectively. This design optimizes the drug load and release effect of the balloon during delivery and expansion.

[0033] More preferably, the strut has a triangular cross-section, with the base of the triangle close to the balloon body and the opposite corner of the base away from the balloon body.

[0034] In another specific embodiment, the hollow structure is woven from silk threads, preferably woven by cross-weaving of silk threads.

[0035] Preferably, the wire comprises a metal wire, and more preferably a shape memory alloy wire.

[0036] Preferably, the outer side of the balloon body is at least partially coated with a drug.

[0037] The balloon body is usually folded in the first state. In most cases, the folded area is coated with drug and the balloon is deployed at the lesion to release the drug. In addition, in the first state, the area of ​​the folded surface of the balloon body covered by the hollow structure support can also be coated with drug and is held and protected by the balloon body and the hollow structure support during delivery.

[0038] Preferably, the drug includes an antiproliferative drug and / or an immunosuppressive drug, and more preferably includes a hydrophilic antiproliferative drug and / or a hydrophilic immunosuppressive drug.

[0039] Hydrophilic drugs have good water solubility and can rapidly dissolve and be released into the bloodstream during balloon dilation, thus making it easier for them to bind to the vascular wall tissue. However, hydrophilic drugs are also prone to dissolving in the blood during delivery, resulting in significant loss and low delivery efficiency. This application, through its hollow structure design, can minimize drug loss during delivery, especially for hydrophilic drugs, significantly increasing the effective drug loading. This ensures that the drug reaches the lesion site and is rapidly and effectively released into the vascular wall tissue to exert its therapeutic effect.

[0040] Preferably, the portion of the balloon body covered by the hollowed-out support structure is coated with an antiproliferative drug and / or an immunosuppressive drug.

[0041] Compared with the prior art, this application has the following beneficial effects:

[0042] This application utilizes a hollow structure that provides high coverage in the first state (folded state) and exerts contractile pressure on the balloon body, thereby reducing drug detachment during delivery and maximizing the delivery of the loaded drug to the lesion, thus increasing the effective drug load. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the balloon dilation catheter provided in Example 1 during its delivery process;

[0044] Figure 2 This is a schematic diagram of the balloon dilation catheter provided in Example 1 during the drug release process;

[0045] Figure 3 A schematic diagram of the hollow structure 300 of the balloon dilation catheter provided in Example 1 during drug release;

[0046] Figure 4 This is a schematic diagram of a specific implementation of the hollow structure 300 in the second state B.

[0047] Figure 5 This is a schematic diagram of another specific implementation of the hollow structure 300 in the second state B.

[0048] Figure 6 A schematic diagram of another specific implementation of the hollow structure 300 in the second state B;

[0049] Figure 7 This is a schematic diagram of another specific implementation of the hollow structure 300 in the second state B.

[0050] Figure 8 A structural schematic diagram of the cross-section of a 300mm hollow structure support column;

[0051] Figure 9 This is a schematic diagram of the cross-sectional structure of the balloon dilation catheter provided in Example 2. Detailed Implementation

[0052] The technical solution of the present invention will be further explained and described below with reference to specific embodiments. However, it should be noted that the specific embodiments are only a specific implementation and explanation of the essence of the technical solution of the present invention, and should not be construed as a limitation on the scope of protection of the present invention.

[0053] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0054] In the description of this application, it should be understood that the terms "distal" and "proximal" should be understood as viewed from the perspective of the surgical operator, with "distal" being the end furthest from the surgical operator and "proximal" being the end closest to the surgical operator. The term "axial" should be understood as the direction of stent delivery, the length of the guidewire, or the length of the stent, and "radial" should be understood as the direction perpendicular to "axial".

[0055] In the description of this application, it should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0056] Example 1

[0057] like Figures 1-3 ( Figure 1 This is a schematic diagram of the balloon dilation catheter provided in Example 1 during its delivery process. Figure 2 This is a schematic diagram of the balloon dilation catheter provided in Example 1 during the drug release process. Figure 3 As shown in the schematic diagram of the hollow structure 300 of the balloon dilatation catheter provided in Example 1 during drug release, Example 1 provides a balloon dilatation catheter, including:

[0058] The balloon body 100 and the catheter 200 passing through the balloon body 100 include a lumen for accommodating a guidewire and a lumen for introducing expansion fluid, which enables the balloon body 100 to switch between an expanded state A and a folded state B.

[0059] The balloon dilation catheter also includes a perforated structure 300 disposed outside the balloon body 100. The perforated structure 300 has an axially extending length, and the distal end of the perforated structure 300 is fixed to the distal end of the catheter 200. The proximal end of the perforated structure 300 is configured to slide along the catheter 200. When the balloon body 100 is in an inflated state A, the perforated structure 300 is in a second state B; when the balloon body 100 is in a folded state B, the perforated structure 300 is in a first state A.

[0060] In the first state A, the hollow structure 300 applies a pressure greater than 0 to the balloon body 100. This pressure can be understood as the force applied to the balloon body 100 caused by the inward contraction tendency of the hollow structure 300.

[0061] In the second state B, the proximal end of the hollow structure 300 slides to the proximal end of the balloon body 100 and is constrained at the proximal end of the balloon body 100 by the inflated balloon body 100.

[0062] The hollow structure 300 is a mesh woven from shape memory alloy wires. In the first state A, the coverage of the hollow structure 300 is 80% within the axial length of the balloon body 100. Simultaneously, the hollow structure 300 is pre-shaped to have a predetermined inner diameter, which is 90% of the outer diameter of the balloon body 100 in the folded state B. In other examples, the predetermined inner diameter can also be 80% to 95% of the outer diameter of the balloon body 100 in the folded state B. The smaller the predetermined inner diameter, the greater the expansion resistance of the balloon body 100; the larger the predetermined inner diameter, the less pressure the hollow structure 300 exerts on the inflatable body 100, making it easier for the drug to detach during delivery. In the second state B, the coverage of the hollow structure 300 is 31% within the axial length of the balloon body 100. From the first state A to the second state B, the coverage variation rate of the hollow structure 300 within the axial length of the balloon body 100 is 61.3%.

[0063] In the expanded state A, the entire exterior of the balloon body 100 is coated with a drug coating (not shown in the figure). In the folded state B, the balloon body 100 is folded into a petal shape according to a predetermined shape, and then rotated and tightened to reach the folded state B.

[0064] The working principle of the balloon dilation catheter is roughly as follows:

[0065] During delivery, the balloon body 100 is in a folded state (B), and the perforated structure 300 is in a first state (A). At this time, the perforated structure 300 presses against the outer wall of the balloon body 100, relatively fixing the drug on the outside of the balloon body 100. As the balloon body 100 is delivered to the lesion, the expansion fluid enters the inner cavity of the balloon body 100 through the expansion fluid lumen of the catheter 200. The balloon body 100 inflates and gradually expands towards the expanded state (A). During the expansion process, the balloon body 100 applies an outward expansion force to the perforated structure 300, causing the perforated structure 300 to change from the first state (A) to the second state (B). During this process, the coverage of the balloon body 100 by the perforated structure 300 decreases, exposing more of the drug coating, and the drug is released from the balloon body and transferred to the lesion. After the drug release is complete, the expansion fluid is withdrawn from the catheter 200, and the balloon body 100 contracts according to the predetermined state and is removed from the body.

[0066] In the second state B, the hollow structure 300 has a binding effect on the balloon body 100, which can avoid or reduce the dog bone effect that occurs at the narrowing of blood vessels and reduce the risk of balloon body 100 bursting.

[0067] In other embodiments, the drug includes an antiproliferative drug and / or an immunosuppressive drug, more preferably a hydrophilic antiproliferative drug and / or a hydrophilic immunosuppressive drug, such as any one of albumin-bound paclitaxel and albumin-bound docetaxel; or the albumin-bound immunosuppressive drug may also include any one of albumin-bound sirolimus, albumin-bound everolimus, albumin-bound biolimus, albumin-bound tansimolimus, albumin-bound lidafolimus, and albumin-bound zotamamus.

[0068] In a preferred embodiment, the limiting structure 300 has at least one sliding end and the other fixed end, wherein the sliding position of the sliding end is restricted to the outside of the corresponding end of the balloon body 100. If the sliding end of the limiting structure 300 is proximal, the sliding end is restricted to the proximal side of the proximal end of the balloon body 100; if the sliding end of the limiting structure 300 is distal, the sliding end is restricted to the distal side of the distal end of the balloon body 100. In other embodiments, the proximal end of the limiting structure 300 is fixed to the catheter 200, and the distal end of the limiting structure 300 is configured to slide along the catheter 200. The distal end of the limiting structure 300 is positioned at the farthest point without external force, and the limiting structure 300 is in a first state A. After the balloon body 100 is inflated, the limiting structure 300 deforms to a second state B, and the distal end of the limiting structure 300 moves to the vicinity of the distal end of the balloon body 100.

[0069] In one specific implementation, such as Figure 4 As shown, the hollow structure 300 can also be a hollow structure 300 laser-engraved from a shape memory alloy tube. The laser-engraved hollow structure 300 can be a plurality of axially extending pillars 301, which extend from the proximal end to the distal end of the hollow structure 300. Figure 4 (A schematic diagram of a specific implementation of the hollow structure 300 in the second state B).

[0070] In yet another specific implementation, such as Figure 5 As shown, the hollow structure 300 can also be a hollow structure 300 laser-engraved from a shape memory alloy tube. The laser-engraved hollow structure 300 can have a plurality of axially extending pillars 301, the pillars extending from the proximal end to the distal end of the hollow structure 300, and connecting pillars disposed between adjacent axially extending pillars 301. The connecting pillars have S-shaped curved pillars 302 or the connecting pillars have broken-line pillars that are at a certain angle to both the axial and circumferential directions. Figure 5(A schematic diagram of another specific implementation of the hollow structure 300 in the second state B).

[0071] In another specific implementation, such as Figure 6 As shown, the hollow structure 300 can also be a hollow structure 300 laser-engraved from a shape memory alloy tube. The laser-engraved hollow structure 300 can be one or more spiral pillars 304 that rotate circumferentially and advance axially. Figure 6 (A schematic diagram of another specific implementation of the hollow structure 300 in the second state B).

[0072] In another specific implementation, such as Figure 7 As shown, the hollow structure 300 can also be a hollow structure 300 laser-engraved from a shape memory alloy tube. The laser-engraved hollow structure 300 can be a diamond-shaped hollow grid 305 formed by connecting the ends of the pillars. Figure 7 (A schematic diagram of another specific embodiment of the hollow structure 300 in the second state B).

[0073] Hollow structure 300 selected Figure 4 When considering the arrangement of several axial extension struts 301 as shown, it is preferable to use traction wires to maintain the hollow structure 300 in the first state A, applying pressure to the balloon body 100; while selecting Figure 6 When using the spiral support 304 shown, it is preferable to use a predetermined method to maintain the hollow structure 300 in the first state A, applying pressure to the balloon body 100; while for Figure 5 The scheme shown combines the axial extension strut 301 and the bent strut 302 (and / or the zigzag strut). Figure 7 When the diamond-shaped hollow mesh 305 shown or the cross-woven mesh structure shown is used, the hollow structure 300 can be maintained in the first state A by either using traction wires or by using a pre-shaped method, thereby applying pressure to the balloon body 100.

[0074] The distal end of the traction wire is typically connected to the proximal end of the hollow structure, and the distal end extends to the proximal end of the catheter for in vitro manipulation.

[0075] like Figure 8 ( Figure 8 As shown in the structural schematic diagram of the cross-section of the support column of the hollow structure 300, the cross-sectional dimension of the support column of the hollow structure 300 described in this application (such as the axial extension support column 301, the curved support column 302, the spiral support column 304, the zigzag support column, or the support column of the diamond hollow mesh 305, etc.) on the side 101 near the balloon body 100 is larger than the cross-sectional dimension on the side 102 away from the balloon body 100. More preferably, the cross-section of the support column is triangular, with the base of the triangle close to the balloon body 100 and the diagonal of the base of the triangle away from the balloon body 100.

[0076] Example 2

[0077] like Figure 9 ( Figure 9 As shown in the schematic diagram of the cross-sectional structure of the balloon dilation catheter provided in Embodiment 2, Embodiment 2 of this application provides a balloon dilation catheter, comprising:

[0078] The balloon body 100 and the catheter 200 passing through the balloon body 100 include a lumen for accommodating a guidewire and a lumen for introducing expansion fluid, which enables the balloon body 100 to switch between an expanded state A and a folded state B.

[0079] The balloon dilation catheter also includes a perforated structure 300 disposed outside the balloon body 100. The perforated structure 300 has an axially extending length, and the distal end of the perforated structure 300 is fixed to the distal end of the catheter 200. The proximal end of the perforated structure 300 is configured to slide along the catheter 200. When the balloon body 100 is in an inflated state A, the perforated structure 300 is in a second state B; when the balloon body 100 is in a folded state B, the perforated structure 300 is in a first state A.

[0080] In the first state A, the hollow structure 300 applies a pressure greater than 0 to the balloon body 100. This pressure can be understood as the force applied to the balloon body 100 caused by the inward contraction tendency of the hollow structure 300.

[0081] On the catheter 200, a limiting protrusion 210 is provided on the proximal side at a distance L1 from the proximal end of the balloon body 100 to limit the proximal sliding range of the hollow structure 300. In the second state B, the proximal end of the hollow structure 300 slides to the proximal side of the limiting protrusion 210, and the proximal end of the hollow structure 300 cannot slide further distally. The portion of the hollow structure 300 near the distal end is opened by the outward expansion force exerted by the inflated balloon body 100. The limiting protrusion 210 allows the metal-covered portion of the balloon body 100 to be transferred as far as possible towards the proximal end of the uncovered balloon body 100 when the balloon body 100 is inflated, thereby reducing the coverage rate of the hollow structure 300 on the outside of the balloon body 100 and increasing the difference in coverage rate between the first state A and the second state B. The distal end of the hollow structure 300 is fixedly provided on the distal side at a distance L2 from the distal end of the balloon body 100. The two ends of the balloon body 100 are connected to the catheter, with the proximal connection being the proximal end of the balloon body 100 and the distal connection being the distal end of the balloon body 100.

[0082] The specific structure of the hollow structure 300 can be a mesh woven from cross-shaped memory alloy wires, as in Example 1, or it can be a laser-engraved shape memory alloy tube. Figures 3-7 Any of the hollow structures shown is preferably a mesh made of cross-woven shape memory alloy wires. The supports of the hollow structure 300 may also have… Figure 8 The structure shown.

[0083] In Example 2, the length of the balloon body 100 in the first state A is 20 mm, L1 is 3 mm, and the metal coverage of the hollow structure 300 is 80%. In the second state B, the metal coverage of the hollow structure 300 in the axial length of the balloon body 100 is 23%. From the first state A to the second state B, the coverage variation rate of the hollow structure 300 in the axial length range of the balloon body 100 is 71.3%.

[0084] Comparative Example 1

[0085] The difference from Example 1 is that the hollow structure 300 is not provided.

[0086] Performance testing

[0087] The balloon dilation catheters of Example 1, Example 2, and Comparative Example 1 were measured according to the following method:

[0088] (1) The initial drug loading A of the balloon dilatation catheters of Example 1, Example 2 and Comparative Example 1 was determined according to the method in Appendix A, in μg / mm², according to T / ZAMEI0003-2023 Paclitaxel Drug-Coated Balloon Dilatation Catheters 5.12 Paclitaxel Drug Coating Performance. 2 );

[0089] (2) Push the balloon dilation catheters along the guidewire to the target simulated lesion location in the vascular model, with a delivery time of 2 minutes, and then remove the corresponding balloon dilation catheters without dilation;

[0090] (3) The drug loading of the removed balloon dilation catheter was measured again according to T / ZAMEI0003-2023 Paclitaxel Drug Coating Balloon Dilation Catheter 5.12 Paclitaxel Drug Coating Performance, and recorded as the remaining drug loading B;

[0091] Drug delivery loss % = (AB) / A × 100%.

[0092] The drug delivery loss was determined to be 8.5% in Example 1, 8.2% in Example 2, and 45.5% in Comparative Example 1.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A balloon dilation catheter, characterized in that, The balloon dilation catheter includes: A balloon body capable of switching between an expanded state and a folded state, wherein at least a portion of the outer side of the balloon body is coated with a drug-eluting coating; A catheter is inserted inside the balloon body, and the balloon body is located at the distal end of the catheter; A hollow structure is disposed on the outside of the balloon body, at least one of the proximal and distal ends of the hollow structure is fixed to the catheter, and the other end of the hollow structure is slidably disposed on the catheter. The proximal end of the hollow structure is close to the proximal side of the balloon body, and the distal end of the hollow structure is close to the distal side of the balloon body. The hollow structure is in a first state when the balloon body is folded, and in a second state when the balloon body is inflated. In the first state, the hollow structure has a coverage of >50% within the axial length range of the balloon body and applies a pressure greater than 0 to the balloon body.

2. The balloon dilation catheter as described in claim 1, characterized in that, From the first state to the second state, the coverage rate of the hollow structure within the axial length range of the balloon body changes by more than 60%.

3. The balloon dilation catheter as described in claim 1 or 2, characterized in that, In the first state, the coverage of the hollow structure within the axial length range of the balloon body is ≥80%.

4. The balloon dilation catheter as described in any one of claims 1 to 3, characterized in that, The proximal end of the hollow structure is limited to the proximal side of the balloon body; or the distal end of the hollow structure is limited to the distal side of the balloon body. Preferably, a limiting protrusion is provided on the proximal side of the balloon body, and the proximal end of the hollow structure is located on the proximal side of the limiting protrusion; or, a limiting protrusion is provided on the distal side of the balloon body, and the distal end of the hollow structure is located on the distal side of the limiting protrusion.

5. The balloon dilation catheter as described in any one of claims 1 to 4, characterized in that, The hollow structure has a pre-shaped structure or a traction wire at the proximal end, which is used to provide pressure on the balloon body by the hollow structure in the first state; Preferably, the hollow structure is pre-shaped into a contracted state, and the inner diameter of the pre-shaped hollow structure is less than or equal to the outer diameter of the balloon body in the folded state. Preferably, the traction wire extends to the proximal end of the catheter to control the transition of the hollow structure between a first state and a second state.

6. The balloon dilation catheter as described in any one of claims 1 to 5, characterized in that, The hollow structure is formed by axially extending pillars arranged side by side and then converging at both ends; or, the hollow structure is formed by at least one spiral pillar in the same direction winding around; or the hollow structure is formed by a diamond-shaped hollow mesh. Preferably, the hollow structure is formed by laser engraving.

7. The balloon dilation catheter as described in claim 6, characterized in that, The cross-sectional dimension of the support column of the hollow structure is larger on the side closer to the balloon body than on the side farther away from the balloon body; more preferably, the cross-section of the support column is triangular, with the base of the triangle close to the balloon body and the opposite diagonal of the base of the triangle away from the balloon body.

8. The balloon dilation catheter as described in any one of claims 1 to 5, characterized in that, The hollow structure is woven from silk threads, preferably woven by cross-weaving of silk threads; Preferably, the wire comprises a metal wire, and more preferably a shape memory alloy wire.

9. The balloon dilation catheter as described in any one of claims 1 to 8, characterized in that, The outer side of the balloon body is at least partially coated with a drug; Preferably, the drug includes an antiproliferative drug and / or an immunosuppressive drug, and more preferably includes a hydrophilic antiproliferative drug and / or a hydrophilic immunosuppressive drug.

10. The balloon dilation catheter as described in any one of claims 1 to 9, characterized in that, The balloon body is partially coated with antiproliferative drugs and / or immunosuppressive drugs by the hollowed-out support structure.

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