A drug balloon delivery system

Abstract

The utility model provides a kind of drug balloon delivery system, including drug balloon catheter and auxiliary delivery catheter, drug balloon catheter includes the push rod body and main pipe body that are sequentially interconnected, balloon is provided on main pipe body, the outer surface of balloon is provided drug coating, the far end of push rod body is provided with limiting device;Auxiliary delivery catheter includes traction rod body, the far end of traction rod body is provided with protective sleeve, the proximal end of traction rod body is connected base, guide device is also provided on traction rod body, the inner diameter of guide device is less than the outer diameter of limiting device, the inner diameter of protective sleeve is greater than the maximum outer diameter when balloon is in shrinkage state, push rod body can penetrate guide device, and by the cooperation of guide device and limiting device to limit forward in the push process of drug balloon catheter and facilitate the withdrawal of auxiliary delivery catheter.The utility model embodiment can reduce the loss rate of drug and convenient operation when operator withdraws auxiliary delivery catheter.

Description

Technical Field

[0001] This utility model relates to the technical field of drug delivery devices, specifically to a drug balloon delivery system. Background Technology

[0002] Minimally invasive surgery has become the main means of treating coronary heart disease or peripheral vascular disease. With the increase in the number of stents used, the problem of in-stent restenosis (ISR) is becoming increasingly serious. The rate of ISR recurrence after simple balloon angioplasty is as high as 27%.

[0003] In recent years, drug-coated balloon (DCB) technology has been increasingly widely used in coronary and peripheral interventional procedures as a novel interventional treatment technique. DCB technology delivers anti-proliferative drugs to the vessel wall via a balloon and releases them evenly, inhibiting the proliferation of vascular endothelial cells, smooth muscle cells, and fibroblasts, thereby reducing restenosis after balloon dilation.

[0004] Drug-coated balloon technology works similarly to drug-eluting stents (DES) in preventing and treating restenosis, both reducing restenosis by inhibiting intimal hyperplasia with the delivered drug. However, they differ in the method of drug delivery and the duration of drug action. The most significant difference lies in the fact that drug-coated balloon technology does not implant a metal wire or polymer coating that remains permanently on the vessel wall, embodying the novel interventional concept of "intervention without implantation." Therefore, as a new interventional treatment technique, drug-coated balloon technology avoids leaving permanent or temporary implants in the blood vessel, thus avoiding a series of problems caused by stent placement.

[0005] While drug-coated balloon technology can alleviate the side effects of balloon angioplasty and stent placement, drug loss during delivery is inevitable, affecting the final treatment outcome. In actual surgery, before reaching the target stenosis, the drug-coated balloon may experience friction from the hemostatic valve, blood flow erosion, vessel wall friction, and relative catheter sliding friction. Furthermore, the moment the balloon opens, these events cause the drug coating to loosen and be lost through blood circulation. If the procedure is not performed correctly or in cases of complex vascular anatomy, a significant portion of the drug on the balloon can be lost during the procedure.

[0006] As can be seen from the above, the drug utilization rate of existing drug-eluting balloons is relatively low, affecting the therapeutic effect. To ensure sufficient drug delivery to the diseased blood vessel wall, the initial drug loading of the balloon must be increased, which poses certain risks to human health. Furthermore, while the aforementioned drug-eluting balloon technology reduces drug loss to some extent, its operation remains inconvenient in clinical applications. Utility Model Content

[0007] The purpose of this utility model embodiment is to provide a drug balloon delivery system to solve the above-mentioned problems existing in the prior art.

[0008] To address the aforementioned technical problems, this utility model provides a drug balloon delivery system, comprising a drug balloon catheter and an auxiliary delivery catheter. The drug balloon catheter includes a push rod and a main tube connected sequentially. A balloon is mounted on the main tube, and a drug coating is applied to the outer surface of the balloon. A limiting device is provided at the distal end of the push rod. The auxiliary delivery catheter includes a traction rod, with a protective sleeve at the distal end and a base connected to the proximal end. A guiding device is also provided on the traction rod. The inner diameter of the guiding device is smaller than the outer diameter of the limiting device, and the inner diameter of the protective sleeve is larger than the maximum outer diameter of the balloon when it is in a contracted state. The push rod can penetrate the guiding device. The cooperation between the guiding device and the limiting device allows for forward limiting of the drug balloon catheter during delivery and facilitates the retraction of the auxiliary delivery catheter.

[0009] In some embodiments, the limiting device is a stepped structure or a circular structure.

[0010] In some embodiments, the proximal end of the push rod is connected to a joint via a strain relief sleeve, the joint having a connection port for connecting to an external inflation or liquid filling device, the strain relief sleeve being used to release stress.

[0011] In some embodiments, the distal end of the main tube has a tip for guiding the guidewire in, and a guidewire lumen exchange bevel is provided near the proximal end of the main tube, the guidewire lumen exchange bevel being connected to the tip through the main tube.

[0012] In some embodiments, the main tube includes an inner tube, an outer tube is sleeved on the inner tube, the gap between the outer tube and the inner tube forms a filling cavity, the inner tube forms a guide wire cavity, and the distal end of the guide wire cavity is sealed to the filling cavity through the tip.

[0013] In some embodiments, the outer tube includes a central outer tube and a distal outer tube arranged axially and connected to each other, the balloon is disposed on the distal outer tube, the central outer tube is connected to the push rod, and the hardness of the distal outer tube is less than that of the central outer tube.

[0014] In some embodiments, the inner tube has a three-layer tube structure, the inner layer of the inner tube is made of high-density polyethylene, the middle layer of the inner tube is used to connect the inner layer and the outer layer and is made of low-density polyethylene; the outer layer of the inner tube is made of polyamide.

[0015] In some embodiments, the distance from the guiding device to the distal end of the protective sheath is greater than the distance from the limiting device to the tip, and the distance from the guiding device to the proximal end of the protective sheath is less than the distance from the limiting device to the distal end of the central outer tube of the drug-eluting balloon catheter.

[0016] In some embodiments, the protective sleeve has a three-layer structure, wherein the inner layer of the protective sleeve is made of low-resistance polytetrafluoroethylene; the outer layer of the protective sleeve is made of polyurethane and polyamide containing barium sulfate; and the middle layer of the protective sleeve is made of wire mesh and / or springs made of nickel-titanium alloy or stainless steel.

[0017] In some embodiments, the guide device is provided with an axially extending slot, the maximum width of which is less than the diameter of the push rod.

[0018] In some embodiments, the guiding device adopts a single-ring structure or a double-ring structure.

[0019] In some embodiments, at least one first indicator is provided on the main tube at a position corresponding to the drug balloon, and a second indicator is provided at a position near the distal end of the protective sleeve.

[0020] In some embodiments, the proximal end of the protective sleeve is provided with a guide exchange bevel.

[0021] In some embodiments, a guidewire and a guiding catheter are also included.

[0022] This invention minimizes the movement of the balloon within the auxiliary delivery catheter during drug delivery and facilitates surgeon withdrawal, making it surgeon-friendly. Furthermore, this invention results in less drug loss during delivery, a simpler structural design, and easier operation, making it more surgeon-friendly. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is an installation schematic diagram of the drug delivery balloon system according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of the drug balloon catheter in the drug delivery system according to an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the auxiliary delivery catheter in the drug balloon delivery system according to an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the installation of the drug balloon catheter and the auxiliary delivery catheter in the drug balloon delivery system according to an embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of the guiding device in the drug delivery system according to an embodiment of the present invention.

[0029] Figure label:

[0030] 100-Drug delivery balloon catheter; 101-Tip; 102-Balloon; 103-First indicator; 104-Main tube; 105-Guidewire lumen exchange bevel; 106-Limiting device; 107-Push rod; 108-Strain release sleeve; 109-Connector; 200-Auxiliary delivery catheter; 201-Second indicator; 202-Protective sleeve; 203-Guide exchange bevel; 204-Traction rod; 205-Guiding device; 2051-Slotted; 206-Base; 300-Guiding tube; 400-Guidewire. Detailed Implementation

[0031] Various embodiments and features of this utility model are described herein with reference to the accompanying drawings.

[0032] It should be understood that various modifications can be made to the embodiments described herein. Therefore, the above description should not be considered as limiting, but merely as an example of embodiments. Other modifications within the scope and spirit of this invention will be apparent to those skilled in the art.

[0033] The accompanying drawings, which are included in and form part of this specification, illustrate embodiments of the present invention and, together with the general description of the present invention given above and the detailed description of the embodiments given below, serve to explain the principles of the present invention.

[0034] These and other features of the present invention will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0035] It should also be understood that although the present invention has been described with reference to some specific examples, those skilled in the art can certainly implement many other equivalent forms of the present invention, which have the features described in the claims and are therefore all within the scope of protection defined herein.

[0036] The above and other aspects, features and advantages of the present invention will become more apparent when taken in conjunction with the accompanying drawings and in view of the following detailed description.

[0037] Specific embodiments of the present invention will now be described with reference to the accompanying drawings; however, it should be understood that the claimed embodiments are merely examples of the present invention, which may be implemented in various ways. Well-known and / or repeated functions and structures have not been described in detail to avoid unnecessary or redundant details that could obscure the present invention. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely to serve as the basis and representative basis for the claims to teach those skilled in the art to use the present invention in a variety of substantially any suitable detailed structures.

[0038] This specification may use the phrases “in one embodiment,” “in another embodiment,” “in yet another embodiment,” or “in other embodiments,” all of which may refer to one or more of the same or different embodiments according to the present invention.

[0039] This utility model provides a drug delivery balloon system that reduces drug loss during drug delivery and release while maintaining ease of operation. Figure 1 As shown, the drug delivery system includes a drug balloon catheter 100 and an auxiliary delivery catheter 200. The drug balloon catheter 100 is provided with a drug for release. In this embodiment, the drug balloon catheter 100 and the auxiliary delivery catheter 200 are used in conjunction with each other. Specifically, after the drug delivery system is delivered to a predetermined position in the human body, the drug balloon catheter 100 is pushed relative to the auxiliary delivery catheter 200, and the drug is released during the pushing process.

[0040] like Figure 2 and combined Figure 1 As shown, the drug-eluting balloon catheter 100 includes a main body 104 and a pusher rod 107, wherein the main body 104 is the relatively distal portion of the drug-eluting balloon catheter 100, and the pusher rod 107 is the relatively proximal portion of the drug-eluting balloon catheter 100, with the distal end of the pusher rod 107 connected to the proximal end of the main body 104; a balloon 102 is disposed on the main body 104, particularly at a position near the distal end of the main body 104.

[0041] Furthermore, the distal end of the main tube 104 has a tip 101, and the balloon 102 is particularly positioned near and inside the tip 101. The tip 101 serves as the entry point for guiding the guidewire of the drug delivery system and enables a smooth transition in extending the guidewire to the balloon 102, thereby avoiding vascular damage. Specifically, the tip 101 is made of a low-hardness polymer material, so that the outer surface of the tip 101 is smooth and soft, avoiding damage to blood vessels and facilitating the guidance of the drug delivery system to the lesion site.

[0042] Furthermore, the push rod 107 is preferably made of a metal material, such as a sodium hypochlorite tube; preferably, the main tube 104 is made of a polymer material, thereby forming a structure that is soft at the distal end and hard at the proximal end, thereby achieving a good combination of tracking and pushing performance.

[0043] Specifically, the balloon 102 is used to expand the lesion site and deliver the drug to the blood vessel wall for release. For this purpose, a drug coating is provided on the outer surface of the balloon 102. The balloon 102 can expand to a predetermined diameter and length using an inflation medium and can return to a contracted state under negative pressure. In this embodiment, the balloon 102 can be shaped, for example, by inflating or stretching a plastic tube.

[0044] In this embodiment, the tip 101, the balloon 102, the main tube 104, and the push rod 107 can be connected by laser welding, bonding, or hot-melt processing.

[0045] Furthermore, a limiting device 106 is provided on the push rod 107, and the limiting device 106 is particularly located at the distal end of the push rod 107. Here, the limiting device 106 can be, for example, a stepped structure. It can also be a ring structure fixed on the push rod 107.

[0046] Furthermore, the main tube 104 includes an inner tube, on which an outer tube is fitted. The gap between the outer tube and the inner tube forms an inflation cavity, providing a channel for the inflation / depressurization of the balloon 102. The inner tube forms a guidewire cavity, providing a channel for the guidewire to pass through. The guidewire, after entering from the tip 101, can pass into the inner tube. Preferably, the distal end of the guidewire cavity and the inflation cavity can be sealed through the tip 101.

[0047] Furthermore, the outer tube includes a central outer tube and a distal outer tube arranged axially. The central outer tube and the distal outer tube are connected by means such as bonding or welding, and the balloon 102 is disposed on the distal outer tube. Preferably, the hardness of the distal outer tube is less than that of the central outer tube, thereby forming a structure in which the distal end of the outer tube is soft and the proximal end is hard, thus achieving a good combination of tracking and pushing performance.

[0048] The inner tube is preferably a three-layer tube, and the outer tube is preferably a single-layer tube. Specifically, the central outer tube and the distal outer tube are extruded single-lumen tubes. The inner layer of the inner tube is preferably made of high-density polyethylene (HDPE), a material with a low coefficient of friction, to reduce the friction of the guide wire. The middle layer of the inner tube connects the inner layer and the outer layer of the inner tube and is preferably made of low-density polyethylene (LDPE). The outer layer of the inner tube cooperates with the outer tube to provide pushing force to the main body 104 and is preferably made of polyamide (PA).

[0049] Furthermore, since the push rod 107 is connected to the main tube 104, specifically, the push rod 107 is connected to the outer tube of the central shaft, the connection can be achieved, for example, by bonding or welding. Preferably, the outer diameter of the connection between the push rod 107 and the outer tube of the central shaft is larger than the outer diameter of the push rod 107, thereby facilitating the formation of the limiting device 106, for example, a stepped structure.

[0050] Furthermore, the main body 104 is provided with a guidewire cavity exchange bevel 105, which is particularly located near the proximal end of the main body 104. The guidewire cavity exchange bevel 105 communicates with the tip 101 through the inner tube. Therefore, the guidewire cavity exchange bevel 105 connects the guidewire cavity (formed through the inner tube) within the main body 104 to the outside, thereby providing an outlet for the guidewire. Preferably, the guidewire cavity exchange bevel 105 can be formed by mechanical drilling or hot melting.

[0051] Preferably, at least one first indicator 103 is provided on the main tube 104 at a position corresponding to the drug-eluting balloon 102. The first indicator 103 enables real-time positioning of the balloon 102, and can be particularly disposed on the inner tube of the main tube 104. The first indicator 103 can be made of materials such as tungsten alloy or platinum-iridium alloy. The position of the balloon 102 can be determined by X-ray imaging of the first indicator 103. In this embodiment, the first indicator 103 can be disposed on the inner tube by laser welding, mechanical embedding, or coating with a polymer material.

[0052] Furthermore, the proximal end of the push rod 107 is connected to a connector 109, which has a connection port for connecting to an external inflation or liquid filling device, such as a pressure pump. The external inflation or liquid filling device inflates / depressurizes the balloon 102 located distal to the main tube 104 via the inflation cavity on the push rod 107 and the main tube 104. Additionally, a strain release sleeve 108 is provided on the connector 109, and the proximal end of the push rod 107 is connected to the strain release sleeve 108, which is used to release stress.

[0053] Specifically, in this embodiment, the connector 109 is made of medical-grade plastic, and the strain relief sleeve 108 is preferably made of at least one material selected from polyolefin (PO), thermoplastic polyurethane elastomer (TPU), and block polyamide (Pebax). The connector 109 and the strain relief sleeve 108 can be integrally molded by injection molding and connected to the end of the push rod 107 by means of bonding or other methods.

[0054] like Figure 3 As shown, the auxiliary delivery conduit 200 includes a traction rod 204, which is preferably made of stainless steel or nickel-titanium material, thus having excellent mechanical properties and good pushing ability.

[0055] Furthermore, a protective sleeve 202 is provided at the distal end of the traction rod 204, and a base 206 is connected to the proximal end of the traction rod 204. The inner diameter of the protective sleeve 202 at the distal end of the traction rod 204 is larger than the maximum outer diameter of the balloon 102 in its contracted state, so that the balloon 102 in its contracted state can be accommodated within the protective sleeve 202, thereby reducing drug loss during the pushing or retraction of the balloon 102 within the auxiliary delivery catheter 200. In this embodiment, the gap between the protective sleeve 202 and the balloon 102 can be larger than in the prior art, achieving minimal friction between the protective sleeve 202 and the balloon 102, and minimizing drug loss.

[0056] The protective sleeve 202 described here can be formed by one-time flow molding of multi-layer materials. For example, when the protective sleeve 202 includes a three-layer structure of an inner layer, a middle layer and an outer layer, the material of the inner layer is preferably low-resistivity polytetrafluoroethylene; the material of the outer layer is preferably polyurethane and polyamide containing barium sulfate with excellent comprehensive mechanical properties and good formability; the middle layer is preferably made of wire mesh and / or springs made of nickel-titanium alloy, stainless steel, etc., for example, forming a metal reinforcing layer composed of nickel-titanium wire mesh and springs to provide support force.

[0057] In this embodiment, the protective sleeve 202 and the traction rod 204 of the auxiliary delivery conduit 200 are assembled by laser welding or brazing, resulting in high connection strength. Preferably, the outer surface of the protective sleeve 202 is coated with a hydrophilic or hydrophobic coating to reduce friction and improve delivery performance. The base 206 is preferably made of polycarbonate or polyamide injection molding for ease of operation by the surgeon.

[0058] Furthermore, a guiding device 205 is also provided on the traction rod 204. In this embodiment, the guiding device 205 cooperates with the limiting device 206 in the drug delivery balloon catheter 100 to forward limit the drug delivery balloon catheter 100, preventing the balloon 102 from extending out of the auxiliary delivery catheter 200 during delivery, thereby achieving efficient treatment of the stenotic lesion. The guiding device 205 is preferably made of nickel-titanium or stainless steel. Here, the guiding device 205 and the traction rod 204 are connected by laser welding or brazing.

[0059] During drug delivery, the drug balloon catheter 100 maintains coaxiality with the auxiliary delivery catheter 200 through the combined action of the protective sleeve 202 and the guiding device 205. Furthermore, the guiding device 205, in cooperation with the limiting device 106, prevents the balloon 102 from extending out of the auxiliary delivery catheter 200 during delivery, thereby improving the utilization rate of the drug coated on the drug-coated balloon 102.

[0060] Specifically, the guiding device 205 has an axially extending through hole, the inner diameter of which is larger than the outer diameter of the pushing rod 107, allowing the pushing rod 107 to extend into the through hole and pass through the guiding device 205. Here, the traction rod 204, guided by the guiding device 205, can slide along the extending direction of the pushing rod 107, causing the protective sheath 202 at the distal end to move axially along the balloon 102. After the balloon 102 is moved to the target position, the protective sheath 202 on the traction rod 204 can be slid outward along the extending direction of the pushing rod 107 of the drug-eluting balloon catheter 100, facilitating the operator's withdrawal operation.

[0061] Furthermore, the guide device 205 is provided with an axially extending slot 2051, the maximum width of which is smaller than the diameter of the push rod 107. The slot 2051 allows the push rod 107 of the drug balloon catheter 100 to be accommodated within the guide device 205, thus preventing the push rod 107 from separating from the guide device 205.

[0062] Furthermore, the inner diameter of the guiding device 205 is smaller than the outer diameter of the limiting device 106 of the drug balloon catheter 100. In this way, the guiding device 205 slides along the pushing rod 107 to the limiting device 106 and engages with the limiting device 106, thus preventing it from sliding forward to achieve the limiting effect. Then, the auxiliary delivery catheter 200 continues to be pushed, thereby driving the drug balloon catheter 100 forward together. This can prevent the balloon 102 from extending out of the protective sleeve 202.

[0063] Furthermore, the distance from the guide device 205 to the distal end of the protective sleeve 202 is greater than the distance from the limiting device 106 of the push rod 107 to the tip 101 of the drug balloon catheter 100, and the distance from the guide device 205 to the proximal end of the protective sleeve 202 is less than the distance from the limiting device 106 of the push rod 107 to the distal end of the central outer tube of the drug balloon catheter 100. Therefore, the guide device 205 can be engaged at the position of the limiting device 106, so that the distal outer tube of the drug balloon catheter 100 and the balloon 102 are completely located within the protective sleeve 202.

[0064] In one specific embodiment, the guiding device 205 can adopt a ring structure, such as a single-ring structure or a double-ring structure. The single-ring or double-ring structure may or may not have a groove. If no groove is provided, the push rod 107 of the drug-eluting balloon catheter 100 must first pass through the guiding device 205 before assembly with the connector 109 and the strain release sleeve 108, etc. If a groove is provided, the operator can pre-assemble it externally. This external pre-assembly allows the pre-assembled drug-eluting balloon-assisted delivery system to avoid friction between the balloon 102 and other supporting instruments such as Y-valve and access catheters, as well as the flushing of the drug by intravascular blood flow during delivery. The structure is simple in design and convenient in operation.

[0065] like Figure 4 As shown, when the guiding device 205 adopts a single-ring structure, the guide wire 400, the drug release catheter 100, and the auxiliary delivery catheter 200 are all arranged inside the guiding tube 300. The guiding device 205 is arranged on the traction rod 204 and covers the traction rod 204. The pushing rod 107 is restricted by the slot 2051 and located inside the guiding device 205. The pushing rod 107 is arranged through the guiding device 205.

[0066] like Figure 5As shown, when the guiding device 205 has a double-ring structure, the guide wire 400, the drug release catheter 100, and the auxiliary delivery catheter 200 are all arranged inside the guiding tube 300. One ring of the guiding device 205 covers the traction rod 204, and the push rod 107 is restricted by the slot 2051 of the other ring of the guiding device 205 and located inside the guiding device 205. The push rod 107 is arranged through the guiding device 205.

[0067] In this embodiment, the guiding device 205 is preferably disposed at the distal end of the traction rod 204 of the auxiliary delivery conduit 200, and the limiting device 106 is disposed on the push rod 107 as close as possible to the balloon 102, thus facilitating force transmission by utilizing the high strength of the push rod 107. After the drug balloon delivery system is pre-assembled, the guiding device 205 is located at the closest position to the balloon 102. With the constraint of the external guiding tube, the coaxial effect between the balloon 102 and the protective sleeve 202 is optimized, preventing the balloon 102 from moving back and forth in the auxiliary delivery conduit 200 during delivery.

[0068] In this embodiment, the distal outer tube of the main tube body 104 of the drug-eluting balloon catheter 100 is located within the protective sheath 202, and the central outer tube of the main tube body 104 is located between the guiding device 205 and the protective sheath 202. This structural design is simple and does not affect guidewire operation, while leveraging the good pushing force of the central outer tube to achieve easy advancement.

[0069] Furthermore, a second indicator 201 is provided at the distal end of the protective sheath 202. This second indicator 201 can be, for example, a contrast ring, to facilitate real-time positioning of the auxiliary delivery catheter 200 during the procedure and to observe the separation between the balloon 102 and the auxiliary delivery catheter 200. The second indicator 201 can be a tantalum ring or a platinum-iridium ring.

[0070] Furthermore, the proximal end of the protective sleeve 202 is provided with a guide exchange bevel 203, which is used for rapid exchange of guidewires or drug-eluting balloons. Here, the protective sleeve 202 and the traction rod body 204 are connected as a single unit via the guide exchange bevel 203. Preferably, the guide exchange bevel 203 is made by laser cutting a metal steel tube.

[0071] like Figure 4As shown, after assembling the auxiliary delivery catheter 200, the drug balloon catheter 100, and the matching largest guidewire 400, its maximum outer diameter should be smaller than the inner diameter of the matching smallest guidewire 300.

[0072] The working principle of the drug delivery system using the embodiments of this utility model is specifically described as follows:

[0073] Before using the drug delivery system clinically, the auxiliary delivery catheter 200 and the drug balloon catheter 100 must be pre-assembled in vitro. The balloon 102 is inserted into the auxiliary delivery catheter 200, with the tip 101 of the drug balloon catheter 100 just extending out of the protective sheath 202. The push rod 107 of the drug balloon catheter 100 is then inserted into the guide device 205 of the auxiliary delivery catheter 200. The proximal end of the guidewire is inserted from the tip 101 into the guidewire lumen of the drug balloon catheter 100, and then exited through the guidewire lumen exchange bevel 105 and out of the protective sheath 202 of the auxiliary delivery catheter 200.

[0074] Then, the guidewire is secured and the protective sheath 202 is inserted into the guiding catheter 300. The pusher rod 107 of the auxiliary delivery catheter 100 is pushed forward, driving the drug delivery balloon catheter 200 forward. At this time, under X-ray fluoroscopy, the drug delivery balloon catheter 100 is advanced along the guidewire to the target blood vessel position. The auxiliary delivery catheter 200 is then withdrawn, so that the balloon 102 is fully exposed in the blood vessel. The balloon 102 is inflated and the drug is released by pressurization using an external pressure pump, for example.

[0075] A negative pressure is drawn into the balloon 102 by a pressure pump, causing the balloon 102 to contract. After the balloon 102 is fully contracted, the guidewire is fixed and the drug delivery balloon catheter 100 is withdrawn into the auxiliary delivery catheter 200. Finally, the auxiliary delivery catheter 200 and the drug delivery balloon catheter 100 are withdrawn from the body together.

[0076] This invention minimizes the movement of the balloon within the auxiliary delivery catheter during drug delivery and facilitates surgeon withdrawal, making it surgeon-friendly. Furthermore, this invention results in less drug loss during delivery, a simpler structural design, and easier operation, making it more surgeon-friendly.

[0077] Furthermore, the features of the embodiments shown in the accompanying drawings or the various embodiments mentioned in this specification should not be construed as independent embodiments. Rather, each feature described in one example of an embodiment can be combined with one or more other desired features from other embodiments to produce other embodiments not described in words or with reference to the accompanying drawings.

[0078] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application 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 of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A drug delivery balloon system, characterized in that, The device includes a drug-eluting balloon catheter and an auxiliary delivery catheter. The drug-eluting balloon catheter comprises a push rod and a main tube connected in sequence. A balloon is mounted on the main tube, and a drug coating is applied to the outer surface of the balloon. A limiting device is provided at the distal end of the push rod. The auxiliary delivery catheter includes a traction rod with a protective sleeve at its distal end and a base connected to its proximal end. A guiding device is also provided on the traction rod. The inner diameter of the guiding device is smaller than the outer diameter of the limiting device, and the inner diameter of the protective sleeve is larger than the maximum outer diameter of the balloon when it is in a contracted state. The push rod can penetrate the guiding device. The cooperation between the guiding device and the limiting device allows for forward limiting of the drug-eluting balloon catheter during its push and facilitates the retraction of the auxiliary delivery catheter.

2. The drug delivery system according to claim 1, characterized in that, The limiting device is a stepped structure or a circular ring structure.

3. The drug delivery balloon system according to claim 1, characterized in that, The proximal end of the push rod is connected to a joint via a strain relief sleeve. The joint is provided with a connection port for connecting to an external inflation or liquid filling device. The strain relief sleeve is used to release stress.

4. The drug delivery system according to any one of claims 1-3, characterized in that, The distal end of the main tube has a tip for guiding the guidewire in, and a guidewire cavity exchange bevel is provided near the proximal end of the main tube. The guidewire cavity exchange bevel and the tip are connected through the main tube.

5. The drug delivery system according to claim 4, characterized in that, The main body includes an inner tube, an outer tube sleeved on the inner tube, a filling cavity formed by the gap between the outer tube and the inner tube, a guide wire cavity formed by the inner tube, and a seal between the distal end of the guide wire cavity and the filling cavity achieved by the tip.

6. The drug delivery system according to claim 5, characterized in that, The outer tube includes a central outer tube and a distal outer tube that are arranged axially and connected to each other. The balloon is disposed on the distal outer tube. The central outer tube is connected to the push rod. The hardness of the distal outer tube is less than that of the central outer tube.

7. The drug delivery system according to claim 6, characterized in that, The inner tube has a three-layer structure. The inner layer of the inner tube is made of high-density polyethylene, the middle layer of the inner tube is used to connect the inner layer and the outer layer and is made of low-density polyethylene, and the outer layer of the inner tube is made of polyamide.

8. The drug delivery system according to claim 6, characterized in that, The distance from the guiding device to the distal end of the protective sleeve is greater than the distance from the limiting device to the tip, and the distance from the guiding device to the proximal end of the protective sleeve is less than the distance from the limiting device to the distal end of the central outer tube of the drug balloon catheter.

9. The drug delivery system according to claim 1, characterized in that, The protective sleeve has a three-layer structure. The inner layer of the protective sleeve is made of low-resistance polytetrafluoroethylene. The outer layer of the protective sleeve is made of polyurethane and polyamide containing barium sulfate. The middle layer of the protective sleeve is made of wire mesh and / or springs made of nickel-titanium alloy or stainless steel.

10. The drug delivery system according to claim 1, characterized in that, The guide device is provided with an axially extending slot, the maximum width of which is less than the diameter of the push rod.

11. The drug delivery system according to claim 1, characterized in that, The guiding device adopts a single-ring structure or a double-ring structure.

12. The drug delivery system according to claim 1, characterized in that, At least one first indicator is provided on the main tube at a position corresponding to the drug balloon, and a second indicator is provided at the distal end of the protective sleeve.

13. The drug delivery system according to claim 1, characterized in that, The protective sleeve is provided with a guide exchange bevel at its proximal end.

14. The drug delivery system according to claim 1, characterized in that, It also includes guidewires and guide tubes.

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