A thrombolytic catheter system for cerebral venous sinuses

Abstract

This invention provides a thrombolytic catheter system for cerebral venous sinus, relating to the field of medical device technology. It includes a microcatheter and a blocking guidewire. The microcatheter has a drug injection structure and side holes. The side holes have several through-holes distributed circumferentially and axially. The blocking guidewire includes a guidewire body and a blocking portion connected to the guidewire body. By using the microcatheter and blocking guidewire, during use, the blocking guidewire is inserted into the microcatheter, and the blocking portion at the end of the guidewire seals the end of the catheter. Thus, during thrombolytic drug injection, the drug only flows out from the through-holes of the catheter. Multiple through-holes are provided circumferentially and axially. This closed design, where thrombolytic drug flows only from the side holes, increases the contact area between the thrombolytic drug and the thrombus, thereby increasing the probability of vascular patency and reducing catheterization time. This solves problems related to the difficulty of removing cerebral venous sinus thrombi, venous reflux during catheter-based thrombolysis, and intracranial infection.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a thrombolytic catheter system for cerebral venous sinus. Background Technology

[0002] Cerebral venous sinus thrombosis (CVST) is a rare manifestation of thrombosis. It refers to the formation of thrombi in intracranial veins or venous sinuses due to various etiologies, obstructing blood return or impairing cerebrospinal fluid circulation, leading to increased intracranial pressure and focal brain damage. The incidence varies from country to country. CVST is more common in pregnant women, women taking oral contraceptives, and young adults under 45 years of age.

[0003] Common treatment methods include thrombus removal and catheter-based thrombolysis.

[0004] Thromboremoval is a minimally invasive surgical technique that uses catheters and other instruments to remove thrombi from blood vessels, restoring patency. The methods for removing cerebral venous sinus thrombosis differ from those for intracranial arterial thrombosis. Intracranial arterial thrombosis removal includes techniques such as SWIM, SAVE, double-stent thrombosis removal, BADDASS thrombosis removal, and ADAPT, and a wide range of specialized thrombosis removal instruments are available. However, cerebral venous sinus thrombosis removal does not have the same variety of techniques and specialized instruments as intracranial arterial thrombosis. Simple thrombectomy is often insufficient to restore patency in cerebral venous sinus thrombosis; thrombolytic therapy is often required to improve recanalization rates. Furthermore, the thrombectomy process presents several challenges, including difficulty in assessing and diagnosing the nature and burden of the thrombus, difficulty in selecting appropriate treatment devices, risks of thrombus escape, large thrombi that are difficult to remove, the risk of vascular damage from repeated thrombectomies, and the potential for no-reflow problems due to high thrombus burden.

[0005] Catheter-directed thrombolysis is a treatment method that delivers high concentrations of thrombolytic drugs directly to the site of the thrombus through a catheter, allowing the drugs to come into contact with the thrombus and thus achieve a thrombolytic effect. During the procedure, the catheter needs to be inserted distal to the thrombus, which can cause venous reflux problems. Furthermore, this method involves a relatively long catheter placement time and increases the risk of intracranial infection; however, there are currently no dedicated thrombolytic catheter devices available on the market.

[0006] This application addresses the challenges of removing cerebral venous sinus thrombi, venous reflux during catheter-directed thrombolysis, and intracranial infection. Utility Model Content

[0007] The purpose of this invention is to provide a thrombolytic catheter system for cerebral venous sinus, which adopts a side-hole design so that the thrombolytic drug flows out from the side hole of the thrombolytic catheter, increasing the contact area between the thrombolytic drug and the thrombus, increasing the probability of vascular patency, reducing the catheterization time, and solving the problems of difficulty in removing cerebral venous sinus thrombi, venous reflux during catheter-based thrombolysis, and intracranial infection.

[0008] To address the aforementioned problems, this invention provides a thrombolytic catheter system for cerebral venous sinuses, comprising a microcatheter and a blocking guidewire. The microcatheter is equipped with a drug injection structure and a side port segment. The drug injection structure allows drug to be injected into the microcatheter. The drug injection structure can be selected as a valve body connected to the microcatheter or a drug injection port provided on the microcatheter. The side port segment has several through holes distributed circumferentially and axially for drug outflow. The blocking guidewire includes a guidewire body and a blocking portion connected to the guidewire body. The blocking portion is used to block the microcatheter and can be optionally blocked at the end of the microcatheter or at the distal end of the side port segment to prevent drug from flowing out from the end of the microcatheter.

[0009] Preferably, the through holes are arranged in 6 columns, with no less than 10 holes in each column.

[0010] According to one embodiment of the present invention, the hardness of the microcatheter gradually decreases from the proximal end to the distal end, and the hardness can be selected to decrease smoothly or in segments.

[0011] Preferably, the microcatheter includes a first segment and a second segment arranged sequentially from proximal to distal, wherein the hardness of the first segment is greater than that of the second segment, and the length of the second segment is less than that of the first segment.

[0012] Preferably, the length of the second segment does not exceed 50cm.

[0013] Preferably, the first segment consists of three layers, namely an outer layer, a middle layer, and an inner layer from the outside to the inside. The middle layer adopts a structure of spring winding, braiding, or both, in order to increase the rigidity and strength of the catheter. The outer and inner layers are coated with hydrophilic materials to improve the lubricity of the catheter, making it easier for the catheter to be inserted into the blood vessel and improving the blood vessel passage.

[0014] According to one embodiment of the present invention, the microcatheter is provided with a first imaging portion, preferably an imaging mark ring disposed at the distal end of the microcatheter.

[0015] According to one embodiment of the present invention, the blocking guidewire further includes a second imaging section, which is disposed at the blocking section or the guidewire body.

[0016] Preferably, the blocking section contains a developing component material, thereby achieving a combined arrangement of the second developing section and the blocking section.

[0017] According to one embodiment of the present invention, the drug injection structure includes a Y valve, one end of which a blocking guidewire is inserted, and the other end is used to connect to a syringe filled with thrombolytic drugs.

[0018] According to one embodiment of the present invention, the blocking guide wire further includes a handle head connected to the guide wire body. The handle head can be fixed at the Y valve, and can be fixed by threaded tightening or by interference fit clamping.

[0019] According to one embodiment of the present invention, the cross-sectional shape of the through hole includes, but is not limited to, one or more of the following: straight, oblique, or trumpet-shaped. By changing the cross-sectional shape, the injection speed of the thrombolytic drug can be changed to adapt to different usage scenarios.

[0020] According to one embodiment of the present invention, the cross-sectional shape of the through hole is oblique, and the inclination angle is 20°~90°.

[0021] According to one embodiment of the present invention, the cross-sectional shape of the through hole is trumpet-shaped, and the diameter at its maximum position is at least three times the diameter at its minimum position.

[0022] According to one embodiment of the present invention, the through hole includes, but is not limited to, one or more of the following: round hole, elliptical hole, rhomboid hole, regular polygonal hole, and triangular hole. Different shapes are suitable for different scenarios and can achieve different types of thrombolytic drug spraying effects.

[0023] The beneficial effects of this invention are that by setting up a microcatheter and a blocking guidewire, during use, the blocking guidewire is inserted into the microcatheter, and the blocking part at the end of the guidewire is used to seal the end of the catheter. Thus, during the injection of thrombolytic drugs, the drugs only flow out from the through holes of the catheter, and multiple through holes are set in both the circumferential and axial directions. This closed design, in which thrombolytic drugs only flow out from the side holes, increases the contact area between the thrombolytic drugs and the thrombus, thereby increasing the probability of vascular patency, reducing the catheterization time, and solving the problems of difficulty in removing cerebral venous sinus thrombosis, venous reflux during catheter-based thrombolysis, and intracranial infection. Attached Figure Description

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] Figure 1 This is a schematic diagram of the structure of a microcatheter;

[0026] Figure 2 This is a schematic diagram of the unfolded structure of the side hole section;

[0027] Figure 3 This is a schematic diagram of the cross-sectional shape of the through hole;

[0028] Figure 4 This is a schematic diagram of the occlusion guidewire.

[0029] Figure 5 This is a schematic diagram of the overall structure of a thrombolytic catheter system used for cerebral venous sinus treatment. Detailed Implementation

[0030] The following description is only intended to disclose the present invention so that those skilled in the art can implement it. The embodiments in the following description are merely examples, and those skilled in the art will conceive of other obvious modifications. The basic principles of the present invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other solutions that do not depart from the spirit and scope of the present invention.

[0031] A thrombolytic catheter system for cerebral venous sinuses, such as Figure 5 It includes microcatheter 2 and occlusion guidewire 1.

[0032] like Figure 1 The microcatheter 2 includes a drug injection structure 21, a first segment 22, a second segment 23, a side hole segment 24, and a first imaging section 25 arranged sequentially from proximal to distal.

[0033] The drug injection structure 21 can be a valve body connected to the microcatheter 2 or a drug injection port provided on the microcatheter 2. In this embodiment, the drug injection structure 21 includes a Y valve, one end of which is used to insert the blocking guide wire 2, and the other end is used to connect to a syringe filled with thrombolytic drugs. The Y valve is fixed to the proximal end face of the first segment 22 by adhesive or heat fusion.

[0034] The first imaging section 25 is an imaging marker ring located at the distal end of the microcatheter 2. The imaging ring is fixedly connected to the outer surface of the catheter tip and is used to perform imaging to confirm the position of the catheter tip during the surgical procedure.

[0035] The hardness of the microcatheter 2 gradually decreases from the proximal end to the distal end, and the hardness can be reduced smoothly or in segments.

[0036] In this embodiment, a segmented reduction is adopted. Specifically, the outer diameters of the first segment 22 and the second segment 23 are the same, but the hardness of the first segment 22 is greater than that of the second segment 23. The hardness gradually decreases from the first segment 22 to the second segment 23. The cross-section of the first segment 22 is composed of three layers, which are the outer layer, the middle layer and the inner layer from the outside to the inside.

[0037] The middle layer uses a spring-wound, braided, or a combination of both structure to increase the rigidity and strength of the catheter; both the outer and inner layers are coated with hydrophilic materials to improve the lubrication of the catheter, making it easier to insert the catheter into the blood vessel and improving vascular permeability.

[0038] The second segment 23 has a lighter rigidity, making it easier to bend manually and adapt to complex and irregular blood vessels; the second segment L2 is no more than 50cm in length. This design feature makes the catheter more flexible and adaptable during operation, allowing it to pass through blood vessels better and ensuring that thrombolytic drugs can be accurately delivered to the target location.

[0039] It is preferable that the length of the second segment 23 is less than the length of the first segment 22, i.e., L1>L2.

[0040] The side hole section 24 is located in the second section 23. The side hole section 24 is provided with several through holes 241 distributed in the circumferential and axial directions. The through holes 241 are used for the outflow of drugs.

[0041] Preferably, such as Figure 2 The through-hole 241 is set with 6 columns, each column having no less than 10 holes. The number of columns and holes can be adjusted according to actual needs.

[0042] like Figure 3 The cross-sectional shape of the through hole 241 includes, but is not limited to, one or more of the following: straight, oblique, or trumpet-shaped. By changing the cross-sectional shape, the injection speed of the thrombolytic drug can be changed to adapt to different usage scenarios.

[0043] When the cross-sectional shape of the through hole 241 is oblique, the inclination angle α is 20°~90°.

[0044] When the cross-sectional shape of the through hole 241 is trumpet-shaped, the diameter d1 at its maximum position is at least three times the diameter d2 at its minimum position, preferably d1=3d2.

[0045] Through hole 241 includes, but is not limited to, one or more of the following: round hole, elliptical hole, rhomboid hole, regular polygonal hole, and triangular hole. Different shapes are suitable for different scenarios and can achieve different types of thrombolytic drug spraying effects.

[0046] By setting the side hole segment 24, the contact area between the thrombolytic drug and the thrombus is increased, thereby enhancing the thrombolytic effect.

[0047] like Figure 4 The blocking guidewire 1 includes a handle head 11, a guidewire body 12 connected to the handle head 11, and a blocking part 13 connected to the guidewire body 12.

[0048] The occlusion guidewire 1 can slide freely in the microcatheter 2. The guidewire body 12 is preferably made of metal. The handle head 11 is fixed to the end of the metal guidewire by heat fusion. The handle head 11 can be made of ABS, PP, PC or other materials.

[0049] The metal guidewire is made of materials such as SUS304, SUS316, or nickel-titanium alloy, which have biocompatibility and mechanical properties, ensuring that the guidewire can be stably and reliably inserted into the catheter.

[0050] The guidewire body 12 is designed with a flowing shape at the end (similar to a bullet shape), and its diameter d3 is 1.1 to 1.3 times the outer diameter of the microcatheter 2, forming a blocking part 13. This design can effectively block the end of the catheter, prevent the leakage of thrombolytic drugs, and ensure that the thrombolytic drugs can be accurately delivered from the side wall of the catheter to the thrombus site.

[0051] The occlusion guidewire 1 also includes a second imaging section, which is disposed at the occlusion section 13 or the guidewire body 12. Preferably, the occlusion section 13 contains imaging component material, thereby realizing the combination of the second imaging section and the occlusion section 13. The second imaging section facilitates imaging during the operation and allows observation of the tip's position to determine whether the thrombus site has been reached.

[0052] The blocking part 13 is used to block the microcatheter 2, and can be blocked at the end of the microcatheter 2 or at the distal end of the side hole segment 24, preferably blocking the distal opening to prevent the drug from flowing out from the end of the microcatheter 2.

[0053] The overall length of the occlusion guidewire 1 device is not less than 150cm, and the outer diameter of the microcatheter is 3F.

[0054] In use, the occlusion guidewire 1 is inserted into the microcatheter 2, with the occlusion portion 13 at the end of the guidewire precisely sealing the end of the catheter. The handle head 11 of the occlusion guidewire 1 can be tightened or clamped onto the Y valve of the microcatheter with an interference fit. The other end of the Y valve is connected to a syringe filled with thrombolytic drug. During the injection of thrombolytic drug, the drug only flows out from the side hole of the catheter, i.e., the through hole 241, and does not flow out from the occlusion guidewire at the Y valve or the end of the catheter. This closed design, where the thrombolytic drug only flows out from the side hole, increases the contact area between the thrombolytic drug and the thrombus. This increases the probability of vascular patency, reduces catheterization time, and solves problems such as difficulty in removing cerebral venous sinus thrombi, venous reflux during catheter-based thrombolysis, and intracranial infection.

[0055] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functional and structural principles of the present invention have been shown and explained in the embodiments. Without departing from the stated principles, the implementation of the present invention may have any variations and modifications.

Claims

1. A thrombolytic catheter system for cerebral venous sinuses, characterized in that: The device includes a microcatheter (2) and a blocking guidewire (1). The microcatheter (2) is provided with a drug injection structure (21) and a side hole section (24). Drug can be injected into the microcatheter (2) through the drug injection structure (21). The side hole section (24) is provided with a number of through holes (241) distributed circumferentially and axially. The through holes (241) are used for drug outflow. The blocking guidewire (1) includes a guidewire body (12) and a blocking part (13) connected to the guidewire body (12). The blocking part (13) is used to block the microcatheter (2) to prevent the drug from flowing out from the end of the microcatheter (2).

2. The thrombolytic catheter system for cerebral venous sinuses according to claim 1, characterized in that: The microcatheter (2) gradually decreases in hardness from the proximal end to the distal end.

3. The thrombolytic catheter system for cerebral venous sinuses according to claim 2, characterized in that: The microcatheter (2) includes a first segment (22) and a second segment (23) arranged sequentially from the proximal end to the distal end. The first segment (22) has a higher hardness than the second segment (23), and the second segment (23) has a shorter length than the first segment (22).

4. The thrombolytic catheter system for cerebral venous sinuses according to any one of claims 1-3, characterized in that: The microcatheter (2) is provided with a first imaging section (25).

5. The thrombolytic catheter system for cerebral venous sinuses according to claim 4, characterized in that: The blocking guidewire (1) further includes a second imaging section, which is disposed at the blocking section (13) or the guidewire body (12).

6. The thrombolytic catheter system for cerebral venous sinuses according to any one of claims 1-3, characterized in that: The drug injection structure (21) includes a Y valve, and the blocking guidewire (1) also includes a handle head (11) connected to the guidewire body (12), the handle head (11) being able to be fixed at the Y valve.

7. The thrombolytic catheter system for cerebral venous sinuses according to claim 4, characterized in that: The cross-sectional shape of the through hole (241) is one or more of the following: straight, oblique, or trumpet-shaped.

8. The thrombolytic catheter system for cerebral venous sinuses according to claim 7, characterized in that: The cross-sectional shape of the through hole (241) is oblique, with an inclination angle of 20°~90°.

9. The thrombolytic catheter system for cerebral venous sinuses according to claim 7, characterized in that: The cross-sectional shape of the through hole (241) is trumpet-shaped, and its diameter at the maximum position is at least three times the diameter at the minimum position.

10. The thrombolytic catheter system for cerebral venous sinuses according to any one of claims 7-9, characterized in that: The through hole (241) is one or more of the following: round hole, elliptical hole, rhomboid hole, regular polygonal hole, and triangular hole.

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