Flexible intraluminal targeted delivery catheter device

Abstract

The utility model relates to a kind of flexible blood vessel intraluminal targeted delivery catheter device, including the quick exchange section of guide wire, puncture needle sheath, catheter body connected in turn;The quick exchange section of guide wire is located in the front end of puncture needle sheath, and the guide wire exchange passage of micro-guide wire is axially arranged in the quick exchange section of guide wire, and the entrance of guide wire exchange passage is arranged in the end lateral wall of quick exchange section of guide wire close to puncture needle sheath;The catheter body is provided with delivery tube, and the front end of the delivery tube is connected with three puncture needles, which are uniformly distributed in the circumferential direction and located in the puncture needle sheath;The front part lateral wall of puncture needle sheath is uniformly distributed with three puncture needle outlets in the circumferential direction;The rear end of catheter body is connected with puncture needle pusher, which drives delivery tube to realize puncture needle forward and retreat, and the rear end of delivery tube is penetrated by the rear end of puncture needle pusher.The device helps to ensure the uniform distribution of drugs in the blood vessel wall and the surrounding tissue and achieve local drug injection input, optimizes the outer diameter of catheter body, and improves the quality and clinical use efficacy of catheter.

Description

Technical Field

[0001] This utility model relates to a flexible intravascular targeted delivery catheter device. Background Technology

[0002] Natural pathways in the human body, such as blood vessels, the digestive tract, the respiratory tract, and the genitourinary tract, are considered preferred routes for drug delivery due to their inherent advantages. In clinical practice, puncture into blood vessels or endoscopically guided access to these pathways, combined with precise drug release techniques, can significantly improve clinical efficacy. Among these pathways, blood vessels, with their wide distribution, ability to reach the entire body, and lack of limitations imposed by organs and tissue structures, have become the most commonly used and crucial drug delivery route. In this process, intravascular catheters, balloons, and endovascular delivery systems with puncture needles play a vital role. In the treatment of vascular and neoplastic lesions, this mode of directly delivering drugs to the target site for precise local treatment effectively overcomes the limitations of traditional drug administration methods, significantly improving clinical efficacy and reducing the incidence of systemic side effects. In recent years, with the rapid development of biomedical engineering and drug delivery technology, various methods and devices for intravascular local drug delivery have emerged, providing richer and more effective solutions for the treatment of related diseases.

[0003] 1. Traditional Catheters: Traditional vascular interventional therapy, as an important diagnostic and treatment method for vascular diseases, relies on the core mechanism of precisely delivering a catheter to the target vessel of the lesion through an intravascular channel system, followed by local drug infusion or embolization. This technology system, with its significant minimally invasive characteristics and targeted advantages, has formed a standardized operating paradigm in clinical practice. It has demonstrated outstanding clinical application value, especially in transcatheter arterial chemoembolization (TACE) for solid tumors (such as hepatocellular carcinoma), and has become the most mature and evidence-based core treatment modality in the field of interventional oncology.

[0004] However, this technology still has significant limitations in drug delivery. While the first-pass effect can achieve some drug accumulation in the target organ after catheter infusion, the residence time of drug molecules in the lesion area decreases exponentially due to the permeability of the vascular endothelial system and the flushing effect of hemodynamics. Pharmacokinetic studies show that the effective drug concentration in the local interstitial fluid is usually maintained for no more than 2 hours. This short exposure period is insufficient to meet the biological requirements for sustained inhibition of tumor cell proliferation or induction of vascular remodeling. More importantly, in the treatment of benign vascular lesions such as coronary atherosclerosis or peripheral artery stenosis, conventional liquid drug formulations, limited by molecular surface charge characteristics, lipophilic parameters, and binding ability to the extracellular matrix of vascular walls, generally have a transendothelial migration efficiency of less than 5%. This makes it difficult for many drug molecules that exhibit significant anti-proliferative / anti-inflammatory effects in in vitro experiments to achieve effective bioavailability at the target site.

[0005] It is noteworthy that current interventional therapy systems suffer from drug delivery deficiencies that have posed multiple clinical challenges. Systemic drug diffusion not only reduces local therapeutic efficacy (bioavailability is typically less than 20%), but may also trigger dose-dependent myelosuppression or organ toxicity. Furthermore, the mechanical clearance of drugs adhering to the vascular wall by blood flow shear forces, and the drug penetration barrier caused by endothelial dysfunction in diseased vessels, together constitute key pathophysiological barriers limiting the expansion of interventional therapy into benign vascular diseases. Overcoming these mechanistic deficiencies urgently requires collaborative innovation in novel drug delivery systems and precision delivery technologies.

[0006] 2. Drug-Coated Balloons: As an innovative solution, drug-coated balloon (DCB) technology has emerged. DCBs employ a special catheter structure design, with the distal balloon surface treated with nanoscale microporous processing and loaded with a therapeutic drug-excipient composite coating (drug loading density 3-5 μg / mm²). The drug is directed to the vessel wall through the mechanical-fluid coupling effect during balloon expansion. Taking coronary intervention as an example, the mTOR inhibitors (such as rapamycin) or microtubule stabilizers (such as paclitaxel) coated on the balloon surface, upon contact with the diseased vessel wall, act on the tunica media smooth muscle cells through a dual mechanism of passive diffusion and active embedding, increasing the proportion of cell cycle arrest in the G1 phase to approximately 70%, significantly reducing the 6-month restenosis rate compared to traditional bare balloon angioplasty. This technology has been extended to the clinical intervention of peripheral vascular diseases such as lower extremity arteries (Fontaine IIb-IV), renal arteries (stenosis >70%), and subclavian arteries.

[0007] Compared to traditional bare-metal stents (BMS) and drug-eluting stents (DES), the core advantage of DCB lies in its "intervention without implantation" characteristic—achieving therapeutic effects through a single pulse of drug release (with a half-life of approximately 30 seconds), avoiding long-term complications such as late-stage in-stent thrombosis and stent fracture caused by permanent foreign body retention. However, DCB technology still faces two technical bottlenecks: firstly, the drug coating is susceptible to fluid shear forces and vessel wall contact pressure during balloon delivery, resulting in 20-35% of the drug being released prematurely before reaching the target site; secondly, limited by existing sustained-release technologies, the effective drug concentration within the vessel wall is maintained for only about 4 weeks, making it difficult to address complex lesions with diffuse and / or severe calcification.

[0008] 3. Microporous Balloon: Based on the need for precise treatment of vascular stenosis / occlusion, a research team has innovatively developed the Porous Topological Balloon Delivery System (PTBDS). This device is a biomimetic reconstruction of the traditional balloon structure, using a porous foam topology (porosity 65%-80%, pore size 10-50 μm) to replace the traditional closed balloon cavity. Its Young's modulus (0.5-2.0 MPa) is reduced by 40%-60% compared to ordinary balloons, significantly improving the distribution of contact stress on the vessel wall. Its core working mechanism relies on microfluidic principles: when the balloon expands at a pressure of 0.5-3 atm, the therapeutic agent (drug / stem cell suspension) achieves directional penetration into the vessel wall through micron-level interconnected pores (flow rate 0.1-0.5 mL / min), reaching a penetration depth of up to the media (300-500 μm). Experimental studies have shown that when using PTBDS to deliver mesenchymal stem cells, cell adhesion efficiency can be increased to approximately 80% by adjusting pore geometry parameters, and related signaling pathways can be activated to achieve an endothelial differentiation rate of about 42%. However, due to fluid shear forces (>15 dyn / cm²) and the lack of extracellular matrix anchoring points, the loss rate of transplanted cells exceeds 90% after 72 hours, resulting in limited angiogenesis performance.

[0009] This technology also presents hemodynamic challenges: complete blood flow occlusion is required during balloon dilation (occlusion time is often limited to 90 seconds in coronary artery applications), leading to an increase in the TIMI frame rate (normal value <13 frames) to 28±5 frames, and a 3.2-fold increased risk of ventricular arrhythmias. To balance therapeutic efficacy and safety, an intermittent dilation strategy (30-second dilation / 60-second perfusion alternation) is often used in clinical practice, but this results in a decrease in drug penetration efficiency of approximately 40%.

[0010] 4. Microneedle Catheters: In clinical practice, there are two main approaches to enhance drug penetration and prolong its local retention time. The first approach involves modifying the drug itself by loading it with auxiliary active ingredients that enhance penetration / permeability. However, because these auxiliary ingredients may potentially inhibit or weaken the target drug, or even destroy its original physicochemical and biological properties, this method is difficult to implement, and its efficacy is hard to guarantee. The second approach involves direct injection into the area requiring intervention using a catheter with a micro-puncture needle. This method is direct, simple to operate, and can precisely target the release of drugs into the blood vessel wall or perivascular tissue, while prolonging the local drug retention time, making it highly clinically feasible.

[0011] For example, research has developed a smart microneedle-coated balloon catheter (MNBC) based on the concealment and expansion-contraction characteristics of pufferfish spines. This catheter consists of three coating layers: a gelatin layer containing black phosphorus (BP), a drug-carrying microneedle layer, and another BP-containing gelatin layer. In the deflated state, the microneedles are hidden under the outermost gelatin protective layer, making the catheter surface relatively smooth and facilitating movement within the blood vessel. Upon reaching the target site, the BP converts light energy into heat energy under near-infrared (NIR) light irradiation, melting the gelatin layer and exposing the microneedles to penetrate the vessel wall. Simultaneously, after the innermost gelatin layer melts, the microneedles detach from the balloon catheter and remain within the vessel wall, achieving continuous drug release. The advantages of MNBC lie in its responsiveness, penetration capability, and biocompatibility. The NIR-triggered thermal response mechanism enables precise drug release and controlled microneedle exposure. The microneedle design allows it to penetrate the vessel wall, delivering drugs directly to the lesion site, improving local drug concentration and therapeutic efficacy. In addition, the detachment function of microneedles prolongs the drug release time, further enhancing the therapeutic effect.

[0012] However, MNBC also faces some challenges. First, the concentration of BP and the NIR power have a significant impact on temperature rise, requiring precise control to ensure safety and efficacy. Second, the mechanical strength and penetration ability of the microneedles need further optimization to meet the needs of different types of vascular lesions. Furthermore, the biocompatibility and degradation characteristics of BP and gelatin still require in-depth research to ensure long-term safety.

[0013] Based on this concept, various microneedle puncture catheter devices have been used for various tests. For example, the Binlab retractable microneedle catheter. This catheter uses over-the-wire (OTW) technology, with three microneedles spaced 120 degrees apart extending through side holes of the catheter to puncture the blood vessel wall and inject medication. This type of catheter is pushed to the local blood vessel location by a centrally positioned guidewire, and then, through three internally placed microneedles, a nickel-titanium alloy needle with memory function can puncture the blood vessel wall to achieve local drug injection.

[0014] Another type of injection catheter, called NIC (needle injection catheter), is used to inject liquid drugs and stem cells into the myocardium to achieve the purpose of local repair of damaged myocardium.

[0015] When using this type of catheter, a guide tube with a larger outer diameter needs to be inserted first. After entering the target area, the catheter is then inserted through the guide tube, and the microneedle is pushed out through the screw-in device at the tail end to pierce the target tissue for injection and treatment. Therefore, its intravascular superselectivity is poor, making it difficult to enter tortuous and small vascular branches.

[0016] Another similar puncture catheter is used to inject a liquid ablation agent into the renal artery to damage nerves and thus treat renal hypertension. This catheter is inserted using an over-the-wire (OTW) technique; a micro-puncture needle penetrates the renal artery to inject anhydrous ethanol (Ethanol) to destroy the nerves surrounding the renal artery.

[0017] The injection catheter is equipped with three micro-puncture needles at the tip, each needle spaced 120 degrees apart. After the catheter is pushed out, it punctures the renal artery and enters the adventitia of the blood vessel. Anhydrous ethanol is injected to damage the sympathetic nerves around the renal artery, block the transmission of mechanical and chemical stimulation signals from the kidney to the central nervous system, reduce sympathetic nerve tension, and dilate small arteries throughout the body, thereby achieving the purpose of lowering blood pressure.

[0018] Based on the same device, the channel catheter microneedle can also be used to target and inject therapeutic and artificially modified separated and purified cellular components into the tissue sites that need treatment, which can also improve the efficacy of local retention, penetration and transfection.

[0019] 5. Microneedle Balloon Catheter. This catheter combines the features of a balloon and a microneedle, enabling local injection through blood vessel penetration. The eccentrically designed balloon folds in, encasing the microneedle; when the balloon is inflated and opened, the microneedle is released and inserted into the target area for drug injection.

[0020] The key feature of this design lies in the combination of a balloon and microneedles: the balloon is designed to be foldable, enclosing a combined channel containing multiple microneedles. When the catheter reaches the target area, the balloon is inflated, causing the microneedles to be pushed out onto the balloon surface and then, under the pressure of the balloon, pierce the inner wall of the blood vessel to inject therapeutic drugs. Similarly, stem cells, genes, etc., can also be injected to achieve specific local therapeutic purposes.

[0021] The aforementioned devices and instruments are used in tumor treatment to deliver chemotherapy drugs, molecularly targeted drugs, ablation agents, gene drugs, etc., and have achieved certain clinical efficacy.

[0022] In conclusion, the clinical demand for endovascular targeted delivery therapy is enormous, and the invention of numerous catheter devices has initially validated the feasibility and clinical efficacy of these approaches. However, existing methods still have significant room for iteration and improvement. For example:

[0023] 1. The catheter has low flexibility. It is difficult to reach deeper treatment sites through tortuous and delicate blood vessels. The catheters designed using the over-the-wire (OTW) technique mentioned above have four channels (three microneedles and a central independent guidewire channel) in parallel, resulting in a relatively rigid and inflexible catheter. Therefore, it is only suitable for the first-order branches of the aorta, and is difficult to reach secondary branches, distal vessels, and lesions with more tortuous anatomical structures.

[0024] The puncture needle has relatively weak penetration ability. Most micro-puncture needles, because they need to remain unchanged in the extended and expanded state, generally use shape-memory metal materials such as nickel-titanium alloys. This type of metal does have a significant advantage in maintaining its original pre-formed shape, but the material itself is relatively soft. Micro-puncture needles made of this material have difficulty penetrating the tougher vascular structures, especially those in areas of atherosclerosis, and the actual clinical application results are not ideal.

[0025] The number and distribution of puncture needles are insufficient. Partially, the balloon encases the micro-needle catheter because the balloon has only a single folding direction. Therefore, once the balloon is deployed, injection can only be performed in a single location, failing to guarantee a uniform, ring-shaped distribution around the target vessel, thus affecting efficacy. Secondly, the balloon needs to be fully inflated during injection so that the micro-needle can penetrate the vessel with the help of the balloon's expansion. However, inflating the balloon can cause blood flow obstruction, potentially leading to myocardial ischemia and even inducing arrhythmias or myocardial infarction during coronary artery treatment. Therefore, this device is not a perfect solution either.

[0026] The catheter diameter is too large. Similar to the first point, multiple minimally invasive needles are coaxial with the guidewire channel (over-the-wire, OTW), resulting in a larger catheter diameter that is difficult to access smaller-diameter blood vessels. In patients with coronary ischemia or infarction, the lesions are often located in the deep distal branches of the coronary arteries, where the vessels are thinner. This large-diameter catheter is difficult to reach the distal portion, leading to less than ideal delivery of isolated and purified stem cells, virus-transfected stem cells, gene drugs, and sustained-release drugs.

[0027] The design flaws of balloon-based endovascular delivery devices are significant. All endovascular delivery devices based on the balloon inflation principle require temporary blood flow occlusion during balloon inflation (typically lasting 60-180 seconds). While this procedure is relatively short in clinical practice, it can easily trigger drastic changes in endothelial shear stress in stenotic lesions with pre-existing insufficient blood supply and hemodynamic compensation at a critical level (FFR of 0.75-0.80), significantly increasing the risk of iatrogenic vascular injury by 2.8-3.5 times. Therefore, balloon-based endovascular delivery devices have certain design flaws that should be carefully considered in clinical applications. Optimizing the procedure, reducing the frequency of use, and shortening the occlusion time are crucial to minimizing iatrogenic injury.

[0028] The lack of real-time monitoring functionality in intraoperative angiography channels is a significant weakness. Current research and development of various endovascular delivery devices focuses primarily on optimizing injection and delivery efficiency, but there are clear technical shortcomings in the crucial area of ​​intraoperative dynamic assessment and real-time monitoring. This deficiency may lead to potential medical risks in clinical practice. From a technical perspective, intraoperative real-time angiography is an effective solution, enabling precise dynamic assessment and real-time monitoring. It allows for timely and accurate understanding of vascular morphological characteristics, such as vascular dissection, thrombosis, and vasospasm, providing clinicians with a basis for timely intervention. This offers significant advantages in improving surgical safety and effectiveness. Therefore, equipping delivery devices with intraoperative angiography channels has extremely important clinical application value.

[0029] However, 92% of these devices lack an integrated design for intraoperative angiography, forcing operators to insert a dedicated angiography catheter after the procedure (taking 3-5 minutes) for digital subtraction angiography (DSA). During this process, the rate of missed detection of new vascular dissections or acute thrombosis can be as high as 15-21%. This delayed retrospective angiography method makes it difficult to detect and effectively relieve acute complications such as vascular occlusion during drug injection and delivery, thus posing significant medical risks in clinical practice. Because current technologies struggle to achieve a reasonable balance between performance optimization and safety, many endovascular delivery devices, despite complex development processes, still face significant challenges in clinical translation and widespread application. Utility Model Content

[0030] The purpose of this invention is to provide a flexible intravascular targeted delivery catheter device, which helps to ensure the uniform distribution of drugs in the blood vessel wall and surrounding tissues and realize local drug injection, optimizes and reduces the outer diameter of the catheter body, and improves catheter quality and clinical efficacy.

[0031] The technical solution of this utility model is as follows: a flexible endovascular targeted delivery catheter device, comprising a guidewire rapid exchange section, a puncture needle sheath, and a catheter body connected in sequence; the guidewire rapid exchange section is located at the front end of the puncture needle sheath, and a guidewire exchange channel for a microguidewire is axially arranged within the guidewire rapid exchange section, with the inlet of the guidewire exchange channel located on the side wall of the guidewire rapid exchange section near the puncture needle sheath; a delivery tube is disposed within the catheter body, and three puncture needles evenly arranged circumferentially and located within the puncture needle sheath are connected to the front end of the delivery tube; three puncture needle outlets are evenly distributed circumferentially on the front side wall of the puncture needle sheath; a puncture needle pushing device is connected to the rear end of the catheter body to drive the delivery tube to push and retract the puncture needles, and the rear end of the delivery tube extends out from the rear end of the puncture needle pushing device.

[0032] Furthermore, the rear part of the guidewire rapid exchange section has an arc-shaped connection portion that connects to the puncture needle sheath so that the axis of the guidewire exchange channel is not on the same axis as the axis of the catheter body.

[0033] Furthermore, the three puncture needle outlets are evenly distributed on the front sidewall of the puncture needle sheath at 120° intervals. The puncture needles are in an outward arc shape, and the three puncture needles are connected to the delivery tube in the lumen of the catheter body through the puncture needle-delivery tube connection.

[0034] Furthermore, a guide cone is provided inside the puncture needle sheath and near the rear end of the puncture needle outlet. The guide cone has three guide cone peep holes evenly distributed along the circumferential direction for the puncture needle to pass through. The guide cone peep holes are inclined outward from the rear to the front.

[0035] Furthermore, the puncture needle pushing device includes a tube body connected to the rear end of the catheter body, a pushing slider slidably connected to the tube body, the pushing slider having an intermediate connecting part that penetrates the tube body and is fixed to the outer wall of the delivery tube, and a matching sliding limiting structure is provided between the pushing slider and the outer wall of the tube body.

[0036] Furthermore, the sliding limiting structure includes a left limiting groove and a right limiting groove disposed on the left and right side walls of the tube body, and the left and right inner walls of the push slider are respectively provided with guide keys that mortise and tenon cooperate with the left limiting groove and the right limiting groove.

[0037] Furthermore, the top and bottom of the tube are respectively provided with an upper guide rail groove and a lower guide rail groove, and the middle connecting part passes through the upper guide rail groove and the lower guide rail groove and is fixedly connected to the conveying pipe; the surfaces of the limiting groove and the guide rail groove are both provided with a scale in mm.

[0038] Furthermore, an infusion tube base is fixed to the rear side wall of the catheter body, and a side infusion tube that communicates with the catheter body is connected to the infusion tube base.

[0039] Furthermore, the front outer wall of the guidewire rapid exchange section is wrapped with an X-ray-proof front metal marking ring, and the front and rear outer walls of the puncture needle sheath are respectively wrapped with an X-ray-proof middle metal marking ring and a rear metal marking ring.

[0040] Furthermore, both the delivery tube and the puncture needle are made of medical steel 440, and the rear end of the delivery tube is provided with a tail end interface.

[0041] Compared with the prior art, the present invention has the following advantages:

[0042] 1. This flexible endovascular targeted delivery catheter device is suitable for clinical medicine, ischemic / tumor diseases, atherosclerosis, coronary heart disease, myocardial infarction, and vascular interventional treatment.

[0043] 2. Traditional micro-puncture needle catheters mostly use a single-needle structure, which can only inject drugs from a single location, making it difficult to achieve uniform distribution of drugs in the tissues surrounding blood vessels, thus limiting the therapeutic effect of drugs.

[0044] This invention employs a multi-needle design with three micro-puncture needles evenly arranged at 120° intervals. This design ensures uniform distribution of the drug within the blood vessel wall and surrounding tissues, enabling local drug injection. For most dose-dependent therapeutic drugs, this design can significantly improve drug efficacy and optimize treatment results.

[0045] 3. Conventional endovascular puncture and injection catheters use the guidewire coaxial (OTW) design, where the guidewire and catheter are in the same channel. This results in a larger catheter diameter and a harder material, which is not conducive to rotation and manipulation and increases the difficulty of manufacturing.

[0046] The flexible endovascular targeted delivery catheter device of this utility model adopts a guidewire rapid exchange channel. (1) It can quickly introduce the catheter into the lesion target area, simplifying the operation difficulty. (2) It reduces the diameter of the catheter body and avoids the puncture needle and guidewire being arranged coaxially. (3) The rapid exchange channel and the catheter body are not arranged side by side. This distributed structure design can effectively reduce the overall outer diameter of the catheter. The smaller outer diameter not only facilitates the catheter to enter the narrower blood vessels, but also significantly reduces the manufacturing difficulty of the catheter. (4) During the treatment, the microguidewire can remain in place. Once complications such as vasospasm, dissection, or obstruction occur, and other interventional devices are needed for auxiliary treatment, the small diameter of the microguidewire can be well matched with most treatment devices, thus facilitating rapid exchange operations and effectively relieving complications that occur during the treatment process.

[0047] 4. Traditional injection catheters are typically designed using the guidewire coaxial technique (OTW) or lack any guidewire guidance mechanism at all (e.g., NIC catheters). In this design, multiple metal delivery catheters are arranged coaxially with the catheter sheath and guidewire, resulting in a significant increase in the overall outer diameter of the catheter. This large outer diameter limits its applicability in endovascular treatment, making it suitable only for the treatment of large vessels such as the primary branches of the aorta, while it is difficult to perform interventional procedures on secondary branches or smaller vessels.

[0048] This invention employs a single-channel delivery catheter design, significantly reducing the manufacturing difficulty of the catheter and avoiding the complexity of multi-channel fabrication while effectively reducing the outer diameter of the catheter. While optimizing the catheter structure, it also ensures the catheter's flexibility, enabling it to adapt to the endovascular treatment needs of secondary branches of large vessels and small vessels of similar diameter. Thus, while retaining the advantages of existing catheters, it effectively overcomes most of the shortcomings of endovascular delivery catheters, improving catheter quality and clinical efficacy, and expanding the application range of endovascular therapy.

[0049] 5. Traditional balloon catheters require inflating the balloon to deploy a micro-puncture needle and insert it into a blood vessel for injection. However, balloon inflation blocks blood flow, leading to distal ischemia. If the blood vessel being treated is already narrowed or obstructed, the balloon's blockage of blood flow will further aggravate distal ischemia symptoms. In cases such as coronary arteries, this may cause unnecessary surgery-related complications.

[0050] The flexible endovascular targeted delivery catheter of this invention can maintain continuous blood flow without blocking blood flow when it reaches the target area for injection treatment, thus avoiding distal ischemia and related complications caused by blood flow obstruction.

[0051] 6. Traditional endovascular injection catheters often use nickel-titanium alloy shape memory metal needles to maintain the needle's curvature and outward position along its nearly full length (approximately 100 cm). However, nickel-titanium alloys are relatively soft, making it difficult to sharpen the needle tip, resulting in poor performance when penetrating atherosclerotic plaques and fibrous tissue. Even with the needle fully extended, it is often difficult to penetrate the vessel wall, hindering drug extravasation. Given the limited volume of the vascular wall, excessive injection of liquid drugs can easily lead to intravascular hematoma, vascular muscle layer rupture, or even aortic dissection, resulting in serious complications such as vascular stenosis, obstruction, and ischemia.

[0052] This invention utilizes medical-grade high-strength 440 steel, which is tougher than nickel-titanium alloy, to manufacture micro-puncture needles. These needles possess advantages such as sharpness, toughness, and strong penetrating power, sufficient to penetrate even tough lesion areas. This effectively overcomes the defects of existing catheter materials, improving the safety and effectiveness of intravascular injection. Simultaneously, the unique guide cone structure within the needle sheath features three forward- and outward-extending guide cone peepholes that precisely guide three micro-puncture needles to the exit point and outward. The advantages of this guide cone design are twofold: firstly, it fully utilizes the forward thrust to ensure effective penetration of the vessel wall; secondly, it makes it possible to manufacture tough puncture needles using ordinary medical steel, avoiding the use of pre-formed nickel-titanium alloy (which is relatively soft and lacks sharpness), thereby significantly improving puncture efficiency.

[0053] 7. The side-perfusion channel allows for real-time dynamic monitoring of the entire injection procedure using angiography, and simultaneous therapeutic intervention. This novel endovascular treatment device, through its independently designed side-perfusion channel and injection delivery tube, enables continuous injection of contrast agent for angiography during endovascular injection. This innovative design achieves real-time dynamic monitoring of vascular morphology (including abnormalities such as vascular dissection, thrombosis, and vasospasm), providing a reliable basis for precise operation and timely optimization of treatment plans. Furthermore, the device allows for direct drug injection and other therapeutic interventions through the side-perfusion channel, thereby synchronizing endovascular diagnosis and treatment. This effectively avoids the delayed diagnosis and iatrogenic risks that may result from the lack of real-time angiography capabilities in traditional endovascular delivery devices. A reasonable balance between performance optimization and safety is achieved, which is beneficial for future clinical translation and widespread application. Attached Figure Description

[0054] Figure 1 The following are external views of the flexible intravascular targeted delivery catheter of this utility model in the needle-retrieval state, wherein: A is a side view, B is a top view, and C is a bottom view;

[0055] Figure 2 This is a cross-sectional view of the flexible intravascular targeted delivery catheter of this utility model (midsagittal plane in the needle retraction state).

[0056] Figure 3 For the present utility model Figure 2 Cross-sectional views of sections a1 to a8;

[0057] Figure 4 For the present utility model Figure 2 Cross-sectional views of sections a9 to a13;

[0058] Figure 5 For the present utility model Figure 2 Enlarged view of area D in the middle;

[0059] Figure 6 This is a cross-sectional view of the flexible intravascular targeted delivery catheter of this utility model (mid-horizontal plane in the needle retraction state).

[0060] Figure 7 For the present utility model Figure 6 Enlarged view of area E in the image;

[0061] Figure 8 The following are external views of the flexible intravascular targeted delivery catheter of this utility model in the needle-out state, wherein: A is a side view, B is a top view, and C is a bottom view;

[0062] Figure 9 This is a cross-sectional view of the flexible intravascular targeted delivery catheter of this utility model (center horizontal plane in needle exit state).

[0063] Figure 10 For the present utility model Figure 9 Cross-sectional view of section a1 to a8;

[0064] Figure 11 For the present utility model Figure 9 Cross-sectional view of portions a9 to a12 in the diagram;

[0065] Figure 12 For the present utility model Figure 9 Enlarged view of region F in the image;

[0066] In the diagram: 1. Guidewire rapid exchange section; 1a. Arc-shaped connection; 2. Puncture needle sheath; 3. Catheter body; 4. Puncture needle pusher; 4a. Tube body; 5. Anti-slip push button; 6. Push slider; 7. Delivery tube; 8. Delivery tube outer port; 9. Guidewire exchange channel outlet; 10. Guidewire exchange channel inlet; 11. Puncture needle outlet; 12. Guidewire exchange channel; 13. Front metal marking ring; 14. Middle metal marking ring; 15. Rear metal marking ring; 16. Upper guide rail groove; 17. Lower guide rail groove; 18. Left limiting groove; 19. Right limiting groove; 20. Puncture needle; 21. Puncture needle-delivery tube connection; 22. Delivery tube inner lumen; 23. Left guide key; 24. Right guide key; 25. 26. Delivery tube-push slider connection; 27. Intermediate connection; 28. Tail end interface; 29. ​​Micro guide wire; 30. Side infusion tube base; 31. Side infusion tube; 32. Outer opening of side infusion tube; 33. Side infusion tube channel; 34. Guide cone; 35. Guide cone peep hole. Detailed Implementation

[0067] To make the above-mentioned features and advantages of this utility model more easily understood, specific embodiments are described below in conjunction with the accompanying drawings, but this utility model is not limited thereto.

[0068] refer to Figures 1 to 12

[0069] A flexible endovascular targeted delivery catheter includes a guidewire rapid exchange section 1, a puncture needle sheath 2, and a catheter body 3 connected in sequence. The guidewire rapid exchange section 1 is located at the front end of the puncture needle sheath 2. An axial guidewire exchange channel 12 for the passage of a microguidewire 28 is axially provided within the guidewire rapid exchange section 1. The inlet 10 of the guidewire exchange channel is located on the side wall of the guidewire rapid exchange section 1 near the puncture needle sheath 2, and the outlet 9 of the guidewire exchange channel is located at the front end of the guidewire rapid exchange section 1. A delivery tube 7 is disposed within the catheter body 3, and the front end of the delivery tube 7 is connected to… The catheter body 3 is equipped with three puncture needles 20 that are evenly arranged in a circumferential direction and located inside the puncture needle sheath 2. The front sidewall of the puncture needle sheath 2 has three puncture needle outlets 11 that are evenly distributed in a circumferential direction. The rear sidewall of the catheter body 3 is connected to a side infusion tube 30. The rear end of the catheter body 3 is connected to a puncture needle pushing device 4. The puncture needle pushing device 4 drives the puncture needle 20 to push it forward out of the puncture needle outlet 11 and retract it into the puncture needle sheath 2 by driving the delivery tube 7. The rear end of the delivery tube 7 is passed through the rear end of the puncture needle pushing device 4 and is provided with a tail end interface 27.

[0070] In this embodiment, the rear part of the guidewire rapid exchange section 1 has an arc-shaped connecting portion 1a that connects to the puncture needle sheath 2, so that the axis of the guidewire exchange channel 12 is not on the same axis as the axis of the catheter body 3. Specifically, the axis of the guidewire exchange channel 12 is parallel to the axis of the catheter body 3, and the axis of the guidewire exchange channel 12 is located below the axis of the catheter body 3. The fact that the guidewire exchange channel 12 is not parallel to the catheter body 3 effectively reduces the diameter of the catheter body 3, facilitating manipulation into smaller diameter blood vessels and deeper tissues, while also reducing manufacturing difficulty.

[0071] In this embodiment, the front outer wall of the guidewire rapid exchange section 1 is wrapped with an X-ray-proof front metal marking ring 13 to facilitate marking and positioning during surgery.

[0072] In this embodiment, the outer diameter of the guidewire rapid exchange section 1 is 0.7~0.9mm, and the length is 9~11mm; the diameter of the guidewire exchange channel is 0.45~0.55mm. Specifically, the outer diameter of the guidewire rapid exchange section 1 can be 0.8mm, and the length can be 10mm.

[0073] In this embodiment, the microguidewire 28 is a 0.018-inch microguidewire. The guidewire exchange channel 12 has a diameter of 0.5 mm, allowing the instrument to be introduced into the blood vessel via the 0.018-inch microguidewire 28 for precise guidance of the catheter to the target area. During treatment, the microguidewire 28 remains in place. If complications such as vasospasm, dissection, or obstruction occur, requiring assistance from other interventional devices, the small diameter of the microguidewire 28 allows for good compatibility with most treatment devices, facilitating rapid exchange and effectively relieving complications during treatment.

[0074] In this embodiment, the three puncture needle outlets 11 are evenly distributed at 120° intervals on the front sidewall of the puncture needle sheath 2. This ensures that after the three micro-puncture needles 20 reach the target area, they are pushed forward by the rear puncture needle pusher 4, unfolding anterolaterally from inside the puncture needle sheath 2 and piercing or penetrating the blood vessel wall. The medication is then injected into the delivery tube 7 through the delivery tube opening 8 on the tail end interface 27, thereby achieving the purpose of local targeted therapy. When withdrawn and in the needle retraction state, the puncture needles 20 are encased in the puncture needle sheath 2 and enter and exit the blood vessel through the rapid exchange section 1 of the guidewire at the tip, preventing the puncture needles 20 from protruding outside the catheter and damaging the blood vessel wall.

[0075] In this embodiment, the diameter of the puncture needle sheath 2 is 1~1.5mm and the length is 14~16mm; specifically, the length of the puncture needle sheath 2 can be 15mm.

[0076] In this embodiment, the puncture needle 20 is a hollow needle, prefabricated from medical steel 440 and shaped like an outward arc. After extending from the puncture needle outlet 11, it can spread forward and outward to pierce the blood vessel wall. This material is harder and sharper than conventional nickel-titanium alloys, making it easier to penetrate plaques such as those from atherosclerosis and tough fibrous connective tissue.

[0077] In this embodiment, three puncture needles 20 are connected to the delivery tube 7 within the lumen of the catheter body 3 via the puncture needle-delivery tube connection 21. Liquid substances injected through the delivery tube port 8 on the tail end interface 27 can be delivered to the target site via the three puncture needles 20.

[0078] In this embodiment, a guide cone 33 is provided inside the puncture needle sheath 2 and near the rear end of the puncture needle outlet 20. The guide cone 33 has three guide cone peep holes 34 that are evenly distributed at 120° intervals along the circumferential direction and are used for the passage of three puncture needles 20. The guide cone peep holes 34 are slightly inclined outward from back to front.

[0079] Three micro-puncture needles 20 can be precisely guided to the puncture needle outlet 11 and pushed out through three forward-outward guiding cone apertures 34. Its functional advantages are mainly reflected in the following two aspects: First, the design of the guiding cone 33 can fully utilize the forward thrust, enabling the puncture needles 20 to effectively puncture and penetrate the blood vessel wall; second, the design of this device makes it possible to manufacture sufficiently strong puncture needles 20 using ordinary medical steel, thereby avoiding the use of pre-formed nickel-titanium alloy material (which is relatively soft and lacks sharpness), thus significantly improving puncture efficiency.

[0080] In this embodiment, the outer walls of the front and rear ends of the puncture needle sheath 2 are respectively wrapped with a radiopaque middle metal marking ring 14 and a rear metal marking ring 15, so as to distinguish it from the front guidewire rapid exchange section 1 and the rear catheter body 3, so as to facilitate positioning and calibration during surgery.

[0081] In this embodiment, an infusion tube base 29 is fixed on the rear left side wall of the catheter body 3 near the puncture needle pushing device 4, and the side infusion tube 30 is connected to the catheter body 3 via the infusion tube base 29.

[0082] In practical applications, the side-perfusion cannula 30 has multiple clinical applications. Firstly, it can be used preoperatively to inject saline solution through the external opening 31 to purge air from the catheter, ensuring safe use of the device. Secondly, during surgery, contrast agent can be injected through the external opening 31 to perform real-time angiography of the target area vessels, allowing for precise assessment of the vessels' real-time condition, including the presence of dissection, rupture, spasm, or obstruction. Based on the angiography results, appropriate treatment measures can be taken promptly. For example, in the event of vasospasm, antispasmodic drugs can be directly injected through the side-perfusion cannula, enabling rapid and efficient management of complications.

[0083] In this embodiment, the length of the catheter body 3 is 1000~1200mm, and the diameter is 1~1.5mm. The catheter body 3 and the puncture needle sheath 2 have the same diameter.

[0084] In this embodiment, the puncture needle pushing device 4 includes a tube body 4a connected to the rear end of the catheter body 3. A pushing slider 6 is slidably connected to the tube body 4a. An anti-slip pushing button 5 is provided on the top of the pushing slider 6. The upper surface of the anti-slip pushing button 5 is engraved with a horizontal groove to enhance friction during operation and facilitate forward and backward pushing operations. The pushing slider 6 has an intermediate connecting part 26 that penetrates the tube body 4a and is fixed to the outer wall of the delivery tube 7. The intermediate connecting part 26 is made of polymer material and is tightly connected to the delivery tube 7. A matching sliding limiting structure is provided between the pushing slider 6 and the outer wall of the tube body 4a. The pushing and retraction operations of the puncture needle 20 are performed by moving the pushing slider 6.

[0085] In this embodiment, the sliding limiting structure includes a left limiting groove 18 and a right limiting groove 19, which are partially penetrated and disposed on the left and right side walls of the tube body 4a. The left and right inner walls of the push slider 6 are respectively provided with a left guide key 23 and a right guide key 24, which are respectively tenon-and-mortise engaged with the corresponding left limiting groove 18 and right limiting groove 19. The sliding limiting structure with tenon-and-mortise engagement enables the sliding limiting of the push slider 6 and facilitates stable push-and-retract operations.

[0086] In this embodiment, the top and bottom of the tube body 4a are respectively provided with an upper guide rail groove 16 and a lower guide rail groove 17, and the intermediate connecting part 26 passes through the upper guide rail groove 16 and the lower guide rail groove 17 and is fixedly connected to the conveying pipe 7.

[0087] In this embodiment, the upper guide rail groove 16, the lower guide rail groove 17, the left limiting groove 18, and the right limiting groove 19 cooperate with each other to effectively ensure the stability and smoothness of the pushing process. During the pushing operation, the guide rail grooves provide a precise guiding path for the pushing action, while the limiting grooves apply an effective limiting effect to the puncture needle 20 after it is pushed to the set position, preventing it from sliding backward due to external force or improper operation, thereby ensuring the accuracy and reliability of the entire pushing process.

[0088] In this embodiment, the inner center of the intermediate connecting part 26 is tightly connected to the delivery tube 7 via the polymer material delivery tube-push slider connecting part 25. The intermediate connecting part 26 slides back and forth along the upper guide rail groove 16 and the lower guide rail groove 17 of the pushing device 4 to push the puncture needle 20 to unfold and retract through the puncture needle outlet 11 of the puncture needle sheath 3.

[0089] In this embodiment, the surfaces of the left limiting groove 18, the right limiting groove 19, the upper guide rail groove 16, and the lower guide rail groove 17 are all equipped with scales in millimeters, enabling precise control of the insertion and retraction depth and length of the puncture needle 20. Through the quantitative guidance of the scale markings, the operator can precisely adjust the insertion depth and retraction distance of the puncture needle 20 according to specific needs during the operation, thereby ensuring the accuracy and safety of the surgical procedure and avoiding potential complications caused by improper puncture depth.

[0090] In this embodiment, the diameter of the tube 4a of the puncture needle pushing device 4 is 4-6 mm, and the length is 22-28 mm. Specifically, the diameter of the tube 4a of the puncture needle pushing device 4 is 5 mm, and the length is 25 mm.

[0091] In this embodiment, the length of the push slider 6 can be 10 mm and the width can be 5 mm.

[0092] In this embodiment, the delivery tube 7 penetrates the catheter body 3, and its tail end interface 27 remains exposed at the rear of the puncture needle pushing device 4 when the puncture needle 20 is fully extended. The delivery tube 7 is made of medical steel 440, and its outer diameter is 0.5 mm.

[0093] In this embodiment, the tail end interface 27 is covered with a polymer material layer, which facilitates the connection of peripheral devices such as syringes.

[0094] The catheter employs a single-channel delivery tube design, unlike traditional multi-needle (usually three-needle) micro-puncture needle catheters. In traditional designs, each puncture needle is equipped with an independent delivery tube. While this structure allows for independent operation of multiple puncture needles, it inevitably increases the overall rigidity of the catheter, significantly reducing its flexibility and limiting the maneuverability when navigating tortuous blood vessel branches. Furthermore, the higher catheter rigidity can easily damage the vessel wall during advancement, potentially leading to serious complications such as vascular dissection and rupture.

[0095] In contrast, this invention, through its single-channel delivery tube 7 connected to three puncture needles 20 at the front end, effectively reduces the overall rigidity of the catheter and further decreases its outer diameter. This design not only optimizes the mechanical properties of the catheter, making it easier to rotate, but also significantly improves its ability to pass through small blood vessel branches, thereby expanding the application range of endovascular treatment.

[0096] If this utility model discloses or relates to mutually fixedly connected parts or structural components, then unless otherwise stated, a fixed connection can be understood as: a detachable fixed connection (e.g., using bolts or screws) or a non-detachable fixed connection (e.g., riveting or welding). Of course, mutually fixed connections can also be replaced by an integral structure (e.g., manufactured using a casting process) (except where it is obviously impossible to use an integral forming process).

[0097] In addition, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in this utility model above include states or shapes that are similar to, close to, or approximate with them.

[0098] Any component provided by this utility model can be assembled from multiple individual components, or it can be a single component manufactured by a one-piece molding process.

[0099] The above description is only a preferred embodiment of the present utility model. All equivalent changes and modifications made within the scope of the patent application of the present utility model shall be covered by the present utility model.

Claims

1. A flexible intravascular targeted delivery catheter device, characterized in that, The catheter comprises a guidewire rapid exchange section, a puncture needle sheath, and a catheter body connected in sequence. The guidewire rapid exchange section is located at the front end of the puncture needle sheath, and an axial guidewire exchange channel for a microguidewire is provided within the guidewire rapid exchange section. The entrance of the guidewire exchange channel is located on the side wall of the guidewire rapid exchange section near the puncture needle sheath. A delivery tube is provided inside the catheter body, and the front end of the delivery tube is connected to three puncture needles evenly distributed along the circumference and located inside the puncture needle sheath. Three puncture needle outlets are evenly distributed along the circumference on the front side wall of the puncture needle sheath. A puncture needle pushing device is connected to the rear end of the catheter body to drive the delivery tube to push and retract the puncture needles. The rear end of the delivery tube extends out from the rear end of the puncture needle pushing device.

2. The flexible intravascular targeted delivery catheter device according to claim 1, characterized in that, The rear part of the guidewire rapid exchange section has an arc-shaped connection portion that connects to the puncture needle sheath so that the axis of the guidewire exchange channel is not on the same axis as the axis of the catheter body.

3. The flexible intravascular targeted delivery catheter device according to claim 1, characterized in that, Three puncture needle outlets are evenly distributed at 120° intervals on the front sidewall of the puncture needle sheath. The puncture needles are in an outward arc shape. The three puncture needles are connected to the delivery tube in the lumen of the catheter body through the puncture needle-delivery tube connection.

4. The flexible intravascular targeted delivery catheter device according to claim 1, characterized in that, A guide cone is provided inside the puncture needle sheath and near the rear end of the puncture needle outlet. The guide cone has three guide cone peep holes evenly distributed along the circumference for the puncture needle to pass through. The guide cone peep holes are inclined outward from back to front.

5. The flexible intravascular targeted delivery catheter device according to claim 1, characterized in that, The puncture needle pushing device includes a tube body connected to the rear end of the catheter body, a pushing slider slidably connected to the tube body, the pushing slider having an intermediate connecting part that penetrates the tube body and is fixed to the outer wall of the delivery tube, and a matching sliding limiting structure is provided between the pushing slider and the outer wall of the tube body.

6. The flexible intravascular targeted delivery catheter device according to claim 5, characterized in that, The sliding limiting structure includes a left limiting groove and a right limiting groove provided on the left and right side walls of the tube body, and the left and right inner walls of the push slider are respectively provided with guide keys that mortise and tenon cooperate with the left limiting groove and the right limiting groove.

7. The flexible intravascular targeted delivery catheter device according to claim 6, characterized in that, The top and bottom of the tube are respectively provided with an upper guide rail groove and a lower guide rail groove. The middle connecting part passes through the upper guide rail groove and the lower guide rail groove and is fixedly connected to the conveying pipe. The surfaces of the limiting groove and the guide rail groove are provided with a scale in mm.

8. The flexible intravascular targeted delivery catheter device according to claim 1, characterized in that, The rear side wall of the catheter body is fixed with an infusion tube base, and a side infusion tube that communicates with the catheter body is connected to the infusion tube base.

9. The flexible intravascular targeted delivery catheter device according to claim 1, characterized in that, The front outer wall of the guidewire rapid exchange section is wrapped with an X-ray-proof front metal marking ring, and the front and rear outer walls of the puncture needle sheath are respectively wrapped with an X-ray-proof middle metal marking ring and a rear metal marking ring.

10. The flexible intravascular targeted delivery catheter device according to claim 1, characterized in that, Both the delivery tube and the puncture needle are made of medical steel 440, and the rear end of the delivery tube is provided with a tail end interface.

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