A dual exit rapid exchange microcatheter thrombectomy device

Abstract

This invention relates to the field of cardiovascular thrombus removal technology, specifically to a dual-outlet rapid exchange microcatheter thrombus removal device, comprising a microcatheter body, a main guide tube body, a filter assembly, a working guidewire, and a filter delivery guidewire. The microcatheter body is housed within the main guide tube body. A first outlet is located on the lower left side of the microcatheter body, and a second outlet is located on the upper right side of the microcatheter body. The end of the microcatheter body has a tapered, elliptical opening. The first outlet is connected to the working guidewire for guiding the microcatheter body. The second outlet contains a guide tube and is connected to the filter delivery guidewire. The filter delivery guidewire is connected to a slanted funnel-shaped filter assembly, and the end of the filter assembly is connected to a protective guidewire. This invention, through its single-lumen dual-outlet design, allows for a smaller outer diameter of the microcatheter, resulting in better passage through thrombus sites.

Description

Technical Field

[0001] This invention relates to the field of cardiovascular thrombus removal technology, specifically to a dual-outlet rapid exchange microcatheter thrombus removal device. Background Technology

[0002] The primary clinical treatment for acute myocardial infarction is percutaneous coronary intervention (PCI), which uses guidewires, catheters, and stents to restore blood flow and reduce damage. In cases with a high thrombus burden, the presence of numerous thrombi in the arteries can easily cause microvascular obstruction, necessitating thrombectomy. Common thrombectomy devices include manual aspiration catheters, mechanical thrombectomy devices, and negative pressure suction systems. While these methods are structurally simple, they suffer from drawbacks in practice, including incomplete removal, potential damage to the vascular intima due to improper operation, and a high level of experience required for the operator.

[0003] Existing patent CN209236301U discloses a thrombus retrieval kit, including a guidewire, a guiding catheter, and a dual-channel microcatheter. The dual-channel microcatheter includes a guidewire catheter that allows guidewire insertion and a stent catheter, which are fixedly connected side-by-side. A self-expanding stent is housed within the stent catheter, and a traction device for controlling the self-expanding stent is connected to its end. This kit primarily utilizes a dual-channel microcatheter design. During thrombus retrieval, the guidewire remains within the blood vessel, eliminating the need for repeated guidewire insertions even with multiple stent insertions. In coronary artery thrombus retrieval, the guidewire and self-expanding stent do not interfere with each other, and the self-expanding stent can be completely retrieved into the catheter. However, the dual-channel design, guided by the guidewire, makes the stent prone to rotation, hindering thrombus localization. Furthermore, the dual channels themselves occupy a significant amount of space, and the self-expanding stent requires considerable space for retrieval. Therefore, there is an urgent need for a single-lumen, compact, radially positioned, integrated microcatheter thrombus removal device with a filter positioning mechanism. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a dual-outlet rapid exchange microcatheter thrombus removal device to address the shortcomings of the prior art.

[0005] The technical problem to be solved by the present invention is achieved through the following technical solution: The present invention discloses a dual-outlet rapid exchange microcatheter thrombus removal device, characterized in that it includes a microcatheter body, a main tube body, a filter assembly, a working guidewire, and a filter delivery guidewire. The microcatheter body is fitted inside the main tube body. A first outlet is provided on the lower left side of the microcatheter body, and a second outlet is provided on the upper right side of the microcatheter body. The end of the microcatheter body is provided with a tapered elliptical opening. The first outlet is connected to a working guidewire for guiding the microcatheter body. A guide tube is provided inside the second outlet. The second outlet is connected to a filter delivery guidewire. The filter delivery guidewire is connected to a slanted funnel-shaped filter assembly. The end of the filter assembly is connected to a protective guidewire.

[0006] Furthermore, the working guidewire outside the microcatheter body is fitted with a hook-and-loop fastener, and the hook-and-loop fastener has a hook ear on its side, and the hook-and-loop fastener is connected to an external branch guidewire.

[0007] Furthermore, the external guidewire passes through the elliptical opening and exits from the first outlet, and the protective guidewire passes through the lug and exits from the first outlet via the elliptical opening.

[0008] Furthermore, after the working guide wire passes through the elliptical opening, it is fitted with a hook-and-loop fastener. The hook-and-loop fastener is a flat gyroscope structure with an elliptical cross-section. The hook-and-loop fastener is connected to an independent external guide wire, which passes through the elliptical opening and exits from the first outlet.

[0009] Furthermore, the filter assembly includes a support ring assembly and a filter body. The filter body includes a filter connector for connecting to the filter conveying guide wire. The support ring assembly includes a support ring body and a folding assembly. The support ring body includes an elastic metal wire that is disconnected through the folding assembly. Both ends of the elastic metal wire are connected to the lower part of the filter connector.

[0010] Furthermore, the filter screen connector is fixedly sleeved on the filter screen conveying guide wire, and a take-up and release sleeve is slidably sleeved on the outside of the filter screen connector. The take-up and release sleeve is connected to a take-up and release guide wire, which passes through the second outlet and enters the interior of the microcatheter body.

[0011] Furthermore, the filter body includes a slanted flared opening, the support ring is sleeved with the slanted flared opening of the filter body, the folding assembly includes a first swing bar, a second swing bar and a connector, the connector includes a rotating pair structure, and the connector is provided with a connection hole for connecting to the filter body.

[0012] Furthermore, both the first and second swing bars are provided with magnetic elements in the middle. The outer ends of the first and second swing bars are connected to the filter body. The first and second swing bars are rotatably connected through the connector. The first and second swing bars are symmetrically arranged along the normal line passing through the center of rotation. The magnetic poles of the magnetic elements of the first and second swing bars are symmetrically arranged.

[0013] Compared with the prior art, the present invention has the following advantages: (1) The present invention uses a single-lumen double-outlet design to make the outer diameter of the microcatheter smaller, which improves the passability to the thrombus site. In addition, with the help of the main tube body and valve body, the encapsulated thrombus is withdrawn from the body as a whole, avoiding the thrombus breakage caused by the valve squeezing the filter screen when the thrombus is removed as a whole. (2) This invention uses hook-and-loop fasteners to guide the filter, avoiding damage to the vascular endothelium, causing less damage to the blood vessels, shortening the operation time, and using multiple sets of guide wires in sequence to achieve the guidance of the microcatheter and the precise traction and positioning of the filter. The operation is flexible and does not require other instruments. (3) The present invention utilizes a filter to deliver a guide wire that extends from the side at a specific angle, and combines it with a specific filter telescopic structure to facilitate the accurate positioning and opening of the filter in the distal blood vessel, thereby achieving rapid collection and encapsulation of the thrombus. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the overall structure of Embodiment 2 of the present invention; Figure 3 This is the present invention. Figure 2 A magnified view of a portion of position A in the middle; Figure 4 This is the present invention. Figure 2 A magnified view of a portion of position B in the middle; Figure 5 This is a schematic diagram of the connection relationship of the hook thread 61 of the present invention; 1-Microcatheter body, 11-First outlet, 12-Second outlet, 13-Oval opening, 2-Main guide tube body, 3-Filter assembly, 31-Support ring assembly, 31a-Support ring body, 31b-Retracting sleeve, 31c-Retracting guide wire, 31d-Folding assembly, 31d1-First swing bar, 31d2-Second swing bar, 31d3-Connector, 31d4-Magnetic element, 32-Filter body, 321-Filter connector, 4-Working guide wire, 5-Protective guide wire, 6-External branch guide wire, 61-Hanging thread, 6a-Hanging ear, 7-Filter delivery guide wire. Detailed Implementation

[0015] Example 1 In this embodiment, a simplified structure is used for thrombus removal; for details, please refer to the appendix. Figure 1 This can protect the tissue and prevent the filter body 32 from damaging the blood vessel wall. The filter body 32 can be made of spring-type memory metal material. When not in use, the filter body 32, i.e., the basket, can be retracted into the microcatheter body 1 and delivered to the thrombus through the microcatheter body 1. After the filter body 32 is unfolded, the thrombus cannot detach from the filter body 32, but blood cells can pass through normally.

[0016] The specific working process of this embodiment is as follows: ① The working guidewire 4 is first inserted, passing through the thrombus location, and then the entire microcatheter body 1 is delivered to the coronary blood vessel. After passing the thrombus location, the length of the working guidewire 4 that comes out of the microcatheter body 1 is only a few millimeters; ② The filter delivery guidewire 7 with a basket is pushed forward and extends from the second outlet 12 on the side, and the filter body 32 unfolds; ③ The working guidewire 4 remains stationary, and the microcatheter body 1 and the filter delivery guidewire 7 with a basket are retracted as a whole. The filter body 32 wraps around the thrombus. The filter delivery guidewire 7 is retracted and pulled back until the microcatheter body 1 and the filter delivery guidewire 7 enter the opening of the angiography catheter. In this embodiment, the angiography catheter refers to the catheter that reaches the patient's coronary artery opening from the outside. At this time, the guidewire part connected to the filter body 32 is retracted into the microcatheter. Note that it should not be completely retracted to avoid crushing the thrombus. The filter delivery guidewire 7 and the microcatheter body 1 smoothly enter the angiography catheter, and then the filter delivery guidewire 7 and the microcatheter body 1 are withdrawn from the body as a whole. In addition, a hemostatic valve can be provided at the very end of the angiography catheter. When the filter delivery guidewire 7 and the microcatheter body 1 are withdrawn from the hemostatic valve as a whole, the thrombus will not be crushed.

[0017] Preferably, the distance between the inlet and the outlet of the working guidewire 4 can be set to approximately 5 mm; the protective guidewire 5 at the distal end of the filter body 32 only needs to be approximately 1 cm to guide and prevent damage to blood vessels. The outer opening of the filter body 32 has a slightly elliptical beveled cross-section to facilitate reception from the second outlet 12 into the microcatheter body 1, and the mesh diameter of the filter body 32 is less than 100 micrometers; in this embodiment, the inlet of the working guidewire 4 and the outlet of the basket guidewire can be set close together and obliquely opposite each other to avoid the distance being too far, which would cause the microcatheter body 1 to be inserted too deeply and damage the patient.

[0018] Example 2 In this embodiment, a refined operation plan is used for thrombus removal; the specific structure is detailed in the appendix. Figure 2-5This embodiment discloses a dual-outlet rapid exchange microcatheter thrombus removal device, which specifically includes a microcatheter body 1, a main tube body 2, a filter assembly 3, a working guidewire 4, a protective guidewire 5, an external branch guidewire 6, and a filter delivery guidewire 7. The microcatheter body 1 is fitted inside the main tube body 2, and a valve assembly for sealing can be provided between the end of the main tube body 2 and the microcatheter body 1 as needed.

[0019] The microcatheter body 1 has a first outlet 11 on its lower left side and a second outlet 12 on its upper right side. For ease of storage, a guide tube 121 is provided inside the second outlet 12. This guide tube 121 can also be replaced by a funnel-shaped guide structure, thus simplifying the structure. It provides space for the guide wire portion of the filter body 32 when it is retracted into the microcatheter, and also facilitates the unfolding of the filter body 32 portion from the microcatheter in the initial process. The end of the microcatheter body 1 has a tapered elliptical opening 13, and the first outlet 11 is connected to a guide tube for guiding the microcatheter body 1. The microcatheter body 1 has a working guide wire 4, a guide tube inside the second outlet 12, a filter conveying guide wire 7 passing through the second outlet 12, and a slanted funnel-shaped filter assembly 3 passing through the filter conveying guide wire 7. A hooking thread 61 is fitted onto the working guide wire 4 outside the microcatheter body 1. The hooking thread 61 has a hook ear 6a on its side. After the working guide wire 4 exits through the elliptical opening 13, it is fitted with the hooking thread 61, which is a flat gyroscope structure with an elliptical cross-section. The hooking thread 61 is connected to an independent external branch guide wire 6, which passes through the elliptical opening 13 and exits from the first outlet 11. A protective guide wire 5 is connected to the end of the filter assembly 3. The protective guide wire 5 passes through the hook ear 6a, through the elliptical opening 13, and exits from the first outlet 11.

[0020] The filter assembly 3 includes a support ring assembly 31 and a filter body 32. The filter body 32 includes a filter connector 321 for connecting to the filter conveying guide wire 7. The support ring assembly 31 includes a support ring body 31a and a folding assembly 31d. The support ring body 31a includes an elastic metal wire that is disconnected by the folding assembly 31d. Both ends of the elastic metal wire are connected to the lower part of the filter connector 321.

[0021] The filter screen connector 321 is fixedly sleeved on the filter screen conveying guide wire 7. A take-up sleeve 31b is slidably sleeved on the outside of the filter screen connector 321. The take-up sleeve 31b is connected to a take-up guide wire 31c. The take-up guide wire 31c passes through the second outlet 12 and enters the interior of the microcatheter body 1. The filter screen body 32 includes a flared mouth. The support ring 31a is sleeved with the flared mouth of the filter screen body 32.

[0022] The folding assembly 31d structure is further described below, comprising a first swing bar 31d1, a second swing bar 31d2, and a connector 31d3. The connector 31d3 includes a rotating joint structure and has a connection hole for connection with the filter body 32. Magnetic elements 31d4 are provided at the middle of both the first swing bar 31d1 and the second swing bar 31d2. The outer ends of both the first swing bar 31d1 and the second swing bar 31d2 are connected to the filter body 32. The first swing bar 31d1 and the second swing bar 31d2 are rotatably connected via the connector 31d3. The first swing bar 31d1 and the second swing bar 31d2 are symmetrically arranged along the normal line passing through the center of rotation, and the magnetic poles of the magnetic elements 31d4 of the first swing bar 31d1 and the second swing bar 31d2 are symmetrically arranged. This ensures that the first swing bar 31d1 and the second swing bar 31d2 can maintain their length direction in the same straight line when they are not affected by external forces. When the support ring assembly 31 is not extended from the guide tube, it remains in a folded state. When the support ring assembly 31 is withdrawn, the metal wire of the support ring assembly 31 becomes a smooth curve, thereby ensuring that the elliptical opening 13 can accommodate thrombi entering the filter.

[0023] In actual operation, the dual-outlet rapid exchange microcatheter is pushed along the working guidewire 4 to the thrombus site. The working guidewire 4 passes through the thrombus to reach the distal blood vessel. The filter assembly 3 is inserted along the microcatheter lumen, and the filter delivery guidewire 7 extends at a preset angle through the second outlet 12 on the side. The filter opens radially within the distal blood vessel of the thrombus, forming an interception barrier. While the filter remains open, the microcatheter body 1, along with the filter, is withdrawn proximally. During withdrawal, the thrombus is caught by the filter and moves proximally along with the microcatheter body 1. The thrombus is completely encased between the filter and the microcatheter body 1, preventing fragments from entering the distal blood vessel. The microcatheter body 1, filter assembly 3, and the encased thrombus are then withdrawn from the body. The working guidewire 4 remains in the blood vessel for subsequent delivery of therapeutic devices such as balloons and stents.

[0024] This design employs a single-lumen, dual-outlet design, resulting in a smaller outer diameter of the microcatheter body 1 and improved throughput. The side-hole angle guides the directional opening of the filter, ensuring precise positioning. The directionally opening filter, with its conical and elliptical upper edge design, facilitates entry and exit from the coronary artery. Thrombus removal is achieved through complete retraction, eliminating the need for repeated procedures and avoiding potential intimal damage from rotational cutting. This minimizes vascular injury and shortens surgical time. Specifically, the thrombus removal device in this embodiment utilizes a dual-outlet rapid exchange structure, integrating a distal protective filter and a multi-guidewire restraint system. This enables safe and efficient removal of intravascular thrombi and prevents distal embolism caused by dislodged fragments. Its working principle comprises four stages: insertion and positioning, filter deployment, thrombus removal, and system retrieval.

[0025] During the placement and positioning phase, the microcatheter body 1 is inserted into the main catheter body 2, and the entire device is advanced along the working guidewire 4. The working guidewire 4 enters from the first outlet 11 of the microcatheter body 1, exits through the oval opening 13 at the end, forming a guidewire track, and is then pushed along the working guidewire 4 and through the thrombus. At this time, the filter assembly 3 is completely housed inside the microcatheter body 1 and is in a folded state, so as not to interfere with the passage. The oval opening 13 at the end of the microcatheter body 1 can reduce vascular damage.

[0026] During the filter unfolding stage, after the end of the microcatheter body 1 reaches the predetermined position, the operator pushes the filter delivery guide wire 7 forward through the second outlet 12, pushing the folded filter assembly 3 out from the front end of the microcatheter body 1. The support ring 31a of the filter assembly 3 is made of elastic metal wire and is disconnected by the folding assembly 31d. The first swing bar 31d1 and the second swing bar 31d2 in the folding assembly 31d are provided with magnetic elements 31d4 with symmetrical magnetic poles in the middle. When the filter is pushed out of the microcatheter and constrained, the elastic metal wire rebounds, and at the same time, the symmetrical magnetic poles generate specific forces of mutual repulsion or attraction (according to the design, the symmetrical arrangement of the magnetic poles here can make the two swing bars open outward), thereby automatically unfolding the filter body 32 into a slanted trumpet shape. Thus, the uniform opening of the support ring 31a is ensured by magnetic assistance, avoiding mechanical jamming.

[0027] During the thrombus removal phase, the protective guidewire 5 plays a crucial role. One end of the protective guidewire 5 is connected to the end of the filter assembly 3, and the other end passes through the loop 6a of the hook thread 61 and exits from the first outlet 11 through the oval opening 13. When the microcatheter body 1 and the filter are retracted or advanced as a whole, the protective guidewire 5 is driven by the hooking action of the hook thread 61, maintaining a certain position and shape of the filter and ensuring the directionality of the filter opening. In addition, the independent external guidewire 6 is connected through the hook thread 61, providing additional maneuverability and improving controllability in conjunction with filter operation.

[0028] During the system retrieval phase, after thrombus capture, the filter screen along with the captured thrombus fragments needs to be retrieved to prevent fragments from falling off. The operator performs a ligation operation by manipulating the guidewire 31c. The retraction cannula 31b slides onto the outside of the filter screen connector 321. Its forward retraction process compresses the first swing bar 31d1 and the second swing bar 31d2, overcoming resistance and causing the support ring 31a to contract radially. Simultaneously, the filter screen delivery guidewire 7 is slightly retracted, and the filter screen body 32 is gradually pulled to the vicinity of the second outlet 12. Finally, the entire microcatheter body 1, along with the filter screen assembly 3 and each guidewire, is withdrawn from the body through the main tube body 2, completing the procedure.

[0029] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A dual-outlet rapid exchange microcatheter thrombus removal device, characterized in that: The device includes a microcatheter body, a main tube body, a filter assembly, a working guidewire, and a filter delivery guidewire. The microcatheter body is housed inside the main tube body. The microcatheter body has a first outlet on its lower left side and a second outlet on its upper right side. The end of the microcatheter body has a tapered elliptical opening. The first outlet is connected to a working guidewire for guiding the microcatheter body. The second outlet contains a guide tube and is connected to a filter delivery guidewire. The filter delivery guidewire is connected to a slanted funnel-shaped filter assembly. The end of the filter assembly is connected to a protective guidewire.

2. The dual-outlet rapid exchange microcatheter thrombus removal device according to claim 1, characterized in that: The working guidewire outside the microcatheter body is fitted with a hook-and-loop fastener, and the hook-and-loop fastener has a hook ear on its side. The hook-and-loop fastener is connected to an external branch guidewire.

3. The dual-outlet rapid exchange microcatheter thrombus removal device according to claim 2, characterized in that: The external guidewire passes through the elliptical opening and exits from the first outlet, while the protective guidewire passes through the lug and exits from the first outlet via the elliptical opening.

4. The dual-outlet rapid exchange microcatheter thrombus removal device according to claim 1, characterized in that: After the working guide wire passes through the elliptical opening, it is fitted with a hook fastener. The hook fastener is a flat gyroscope structure with an elliptical cross-section. The hook fastener is connected to an independent external guide wire, which passes through the elliptical opening and exits from the first outlet.

5. The dual-outlet rapid exchange microcatheter thrombus removal device according to claim 1, characterized in that: The filter assembly includes a support ring assembly and a filter body. The filter body includes a filter connector for connecting to the filter conveying guide wire. The support ring assembly includes a support ring body and a folding assembly. The support ring body includes an elastic metal wire that is disconnected by the folding assembly. Both ends of the elastic metal wire are connected to the lower part of the filter connector.

6. The dual-outlet rapid exchange microcatheter thrombus removal device according to claim 5, characterized in that: The filter screen connector is fixedly sleeved on the filter screen conveying guide wire, and a take-up and release sleeve is slidably sleeved on the outside of the filter screen connector. The take-up and release sleeve is connected to a take-up and release guide wire, which passes through the second outlet and enters the interior of the microcatheter body.

7. The dual-outlet rapid exchange microcatheter thrombus removal device according to claim 5, characterized in that: The filter body includes a slanted flared opening, and the support ring is sleeved on the slanted flared opening of the filter body. The folding assembly includes a first swing bar, a second swing bar, and a connector. The connector includes a rotating pair structure and has a connection hole for connecting to the filter body.

8. The dual-outlet rapid exchange microcatheter thrombus removal device according to claim 7, characterized in that: Both the first and second swing bars have magnetic elements in their middle sections. The outer ends of the first and second swing bars are connected to the filter body. The first and second swing bars are rotatably connected through the connector. The first and second swing bars are symmetrically arranged along the normal line passing through the center of rotation. The magnetic poles of the magnetic elements of the first and second swing bars are symmetrically arranged.

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