Intravascular thrombus suction catheter

Abstract

The utility model provides an intravascular thrombus aspiration catheter. The intravascular thrombus aspiration catheter comprises an internal flow channel, a far-end aspiration catheter section, a middle catheter section and a near-end driving catheter section, and the internal flow channel is sequentially communicated with the far-end aspiration catheter section, the middle catheter section and the near-end driving catheter section from the far end of the intravascular thrombus aspiration catheter to the near end of the intravascular thrombus aspiration catheter. Wherein the intravascular thrombus aspiration catheter further comprises an aspiration inlet and an outflow window, and the internal flow channel is communicated with the aspiration inlet and the outflow window; the inner flow channel is provided with an impeller; a suction inlet, an impeller and an outflow window are sequentially arranged from the far end to the near end of the intravascular thrombus suction catheter, and the intravascular thrombus suction catheter further comprises a filter screen. The filter screen is arranged between the impeller of the inner flow channel and the outflow window, or the filter screen is arranged outside the outflow window and wraps the outflow window. According to the intravascular thrombus aspiration catheter, the working load of the impeller can be effectively reduced, and then adverse events caused by excessive heat generated due to large load are reduced.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and in particular to an intravascular thrombus aspiration catheter. Background Art

[0002] At present, the main treatments for thrombotic diseases include: anticoagulant, antithrombotic, thrombolytic and other drug treatments, surgical treatment and interventional treatment. For patients with old thrombi that have not responded well to medical treatment and have poor collateral formation, surgical treatment can be considered, that is, surgical removal of the thrombus or resection of the embolized blood vessel segment and re-anastomosis. Interventional treatment uses local thrombolysis through catheters, low-pressure blood aspiration through catheters, and mechanical thrombectomy through balloons, stents and other devices. After thrombus formation, it is easy to fall off and move with the blood. During the movement, it partially or completely blocks certain blood vessels, causing ischemia, hypoxia, necrosis, etc. of the corresponding tissues and (or) organs. The severity of the impact of thromboembolism is related to the location and duration of embolism.

[0003] In the prior art, patent CN103932756A discloses a thrombus aspiration system, including a thrombus aspiration catheter and a blood bottle connected thereto. The thrombus aspiration catheter adopts an ultra-thin tube wall, a wide inner cavity and a single-lumen pipeline design to ensure smooth and efficient performance during thrombus aspiration. The outer edge of the distal end of the tapered tube section is rounded, which is convenient for the thrombus aspiration catheter to enter the blood vessel as a whole and reduce damage to the human body. The distal end is provided with a spirally distributed elliptical side hole, which is convenient for smoothly aspirating larger thrombi in the blood vessel to prevent the situation where larger thrombi cannot be aspirated, so that the thrombi in the blood vessel can be completely aspirated to achieve the best treatment effect. The blood drawn from the human body during the operation flows into the blood bottle, and the drawn thrombi are filtered out through the thrombus filter in the bottle. The filtered blood can be re-introduced into the human body, so that the autologous blood can be used quickly and effectively, avoiding adverse reactions such as contamination of the patient by allogeneic blood. However, the disadvantage of this method is that when the thrombus is aspirated to the outside of the body, the blood is also aspirated to the outside of the body, resulting in a decrease in the patient's blood volume. In this case, doctors need to be careful to ensure that the patient's blood supply is not overly affected while the clot is removed. Additional measures may be needed to replenish blood or other body fluids to maintain the patient's blood circulation and vital signs. In addition, some thrombectomy devices have improper filter settings, which leads to excessive load on the impeller, resulting in adverse events due to high load and high heat generation during operation.

[0004] Therefore, the prior art still needs to be improved and enhanced. Utility Model Content

[0005] According to an exemplary embodiment of the present disclosure, an intravascular thrombus aspiration catheter is provided, which has a relatively small overall size and can be inserted into a patient's body to directly collect thrombi in the patient's body without relying on extracorporeal circulation equipment; and the intravascular thrombus aspiration catheter can also increase the blood flow rate during the aspiration process, reduce the impeller load, and thereby reduce adverse events caused by heavy load and high heat generation.

[0006] In the first aspect of the present disclosure, an intravascular thrombus aspiration catheter is provided, comprising: an inner flow channel, a distal aspiration catheter segment, an intermediate catheter segment and a proximal drive catheter segment, wherein the inner flow channel sequentially connects the distal aspiration catheter segment, the intermediate catheter segment and the proximal drive catheter segment from the distal end to the proximal end of the intravascular thrombus aspiration catheter, wherein the intravascular thrombus aspiration catheter further comprises a suction inlet and an outflow window, and the inner flow channel connects the suction inlet and the outflow window; the inner flow channel is provided with an impeller; the suction inlet, the impeller and the outflow window are sequentially provided from the distal end to the proximal end of the intravascular thrombus aspiration catheter, and the intravascular thrombus aspiration catheter further comprises a filter; the filter is arranged between the impeller and the outflow window of the inner flow channel, or the filter is arranged outside the outflow window and covers the outflow window.

[0007] Further, in some embodiments, the proximal driving catheter segment also includes a flexible driving shaft and a sheath, the flexible driving shaft is arranged inside the proximal driving catheter segment, the sheath is arranged on the outside of the flexible driving shaft, the proximal driving catheter segment is connected to an external motor through the flexible driving shaft and the sheath, the external motor drives the impeller to rotate so that the blood and thrombus in the internal flow channel of the intravascular thrombus aspiration catheter enter the internal flow channel from the suction inlet and flow toward the outflow window.

[0008] Furthermore, in some embodiments, the filter is constructed of metal nickel-titanium material or polymer material.

[0009] Furthermore, in some embodiments, the filter is configured such that the diameter of the filter holes is 0.1 micrometer to 500 micrometers.

[0010] Furthermore, in some embodiments, the filter screen is constructed to consist of partial filter holes or all filter holes.

[0011] Furthermore, in some embodiments, the filter is constructed as a double-layer structure, comprising a distal filter layer and a proximal filter layer, wherein the filter pore size of the distal filter layer is larger than the filter pore size of the proximal filter layer.

[0012] Further, in some embodiments, when the filter is disposed outside the outflow window and covers the outflow window, the filter is constructed to be made of a polymer TPU material.

[0013] Further, in some embodiments, when the above-mentioned filter is arranged outside the above-mentioned outflow window and covers the above-mentioned outflow window, the above-mentioned filter is arranged to be a forward convex filter, and the above-mentioned forward convex filter is constructed as a structure with a center convex forward, and the above-mentioned center convex forward structure means that the central convex part of the above-mentioned forward convex filter is a structure that convexes toward the distal end of the above-mentioned intravascular thrombus aspiration catheter.

[0014] Further, in some embodiments, when the filter screen is disposed between the impeller and the outflow window of the inner flow channel, the filter screen is constructed to be made of a high molecular weight PLA material.

[0015] Further, in some embodiments, when the filter is disposed between the impeller and the outflow window of the inner flow channel, a flow support structure is disposed near the distal end of the impeller near the intravascular thrombus aspiration catheter, and the flow support structure includes a blood channel and an inner support frame.

[0016] Further, in some embodiments, the inner support frame includes a plurality of support arms, the plurality of support arms are connected to the inner wall of the intravascular thrombus aspiration catheter, and the inner support frame extends a certain distance along the axial direction of the intravascular thrombus aspiration catheter.

[0017] Furthermore, in some embodiments, the blood channel is disposed between the support arms of the inner support frame and extends along the axial direction of the intravascular thrombus aspiration catheter.

[0018] Further, in some embodiments, the inner flow channel is provided with a one-way valve, and the one-way valve is arranged between the suction inlet and the impeller.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The filter part is designed at the rear end of the impeller (i.e., closer to the proximal end than the impeller). For example, the filter is set between the impeller and the outflow window of the inner flow channel, or the filter is set outside the outflow window and covers the outflow window, which is beneficial to increase the blood flow rate during the suction process, reduce the impeller load, and thus reduce adverse events caused by heavy load and high heat generation.

[0021] (2) Furthermore, the diameter of the filter holes in the above-mentioned filter is set to be between 0.1 microns and 500 microns, thereby allowing blood to flow through and effectively intercepting most of the blood clots; and filter holes can also be set partially (or entirely) in the filter to achieve the function of filtering blood clots.

[0022] (3) In the case where the filtering part is designed at the rear end of the impeller, a flow support structure is provided at the distal end of the impeller near the intravascular thrombus aspiration catheter. The flow support structure includes a blood channel and an inner support frame. The inner support frame is used to strengthen the support of the tube section, and the blood channel can ensure that the blood to be sucked and filtered can flow smoothly to the filter screen or the filtering part.

[0023] (4) Furthermore, a one-way valve is provided in the inner flow channel, and the one-way valve is arranged between the suction inlet and the impeller, which can effectively prevent the collected and accumulated thrombus from flowing back into the blood vessel with the backflow of blood when the thrombus suction is stopped suddenly (for example, the impeller stops rotating); and the one-way valve is arranged between the suction inlet and the impeller to prevent the formation of a blood retention area in the inner flow channel of the intravascular thrombus suction catheter, thereby preventing the formation of new thrombus. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. In the accompanying drawings:

[0025] Figure 1 A schematic diagram of an intravascular thrombus aspiration catheter according to some embodiments of the present disclosure is shown;

[0026] Figure 2 A schematic diagram showing an intravascular thrombus aspiration catheter according to other embodiments of the present disclosure; and

[0027] In each of the accompanying drawings, the same or corresponding reference numerals represent the same or corresponding parts; wherein the reference numerals are: intravascular thrombus aspiration catheter 100, 200; distal aspiration catheter segment 110, 210; distal aspiration catheter segment wall 111, 211; suction inlet 112, 212; intermediate catheter segment 120, 220; intermediate catheter segment wall 121, 221; one-way valve 122; proximal drive catheter segment 130, 230; proximal drive catheter segment wall (or pump housing) 131, 231; impeller 132, 232; outflow window 133, 233; transmission catheter 134, 234; thrombus 140; filter screen 170, 270; filter hole 171; support structure 232-1; inner support frame 232-2; blood channel 232-3. DETAILED DESCRIPTION

[0028] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not intended to limit the scope of protection of the present disclosure.

[0029] In the description of the embodiments of the present disclosure, the term "including" and similar terms should be understood as open inclusion, that is, "including but not limited to". The term "based on" should be understood as "based at least in part on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0030] In addition, it should be noted that, in the description of the embodiments of the present application, unless otherwise clearly defined, "in vivo" means inside the tissues and organs of the patient, and "in vitro" means outside the tissues and organs of the patient. At the same time, in the embodiments of the present application, "distal" means the direction away from the physician, and "proximal" means the direction close to the physician.

[0031] Generally, thrombi, especially fresh thrombi, are like jelly in the body, without mechanical strength and easily ruptured in the body. To remove the thrombi with a balloon, it is necessary to block the blood flow in the far side. In order to remove the thrombi as completely as possible, the thrombectomy balloon needs to be attached to the wall, which is easy to scratch the blood vessels when moving. Thrombectomy with a stent is prone to thrombus rupture and incomplete thrombectomy. The catheter negative pressure aspiration of thrombi includes manual aspiration and the Bernoulli effect to aspirate the thrombi to the body. Manual aspiration is unstable and has low aspiration force, and has almost no clinical efficacy. The Bernoulli effect is used for aspiration, and its working process is to drive the pump to generate pulse pressure to inject saline through the catheter and reversely spray from the side hole of the catheter head to flush the thrombus. The high-speed saline simultaneously generates a local low-pressure area, so that the broken thrombus particles are sucked out of the catheter discharge hole. The disadvantage of this method is that while the thrombus is aspirated to the outside of the body, the blood is also aspirated to the outside of the body, resulting in a decrease in the patient's blood volume. In addition, some thrombectomy devices have improper filter settings, which causes excessive impeller load, and then cause adverse events during operation due to heavy load and high heat generation.

[0032] In order to solve at least one of the above problems, as well as one or more of other potential problems, an exemplary embodiment of the present disclosure proposes an intravascular thrombus aspiration catheter, which includes: an inner flow channel, a distal aspiration catheter segment, an intermediate catheter segment, and a proximal drive catheter segment, wherein the inner flow channel sequentially connects the distal aspiration catheter segment, the intermediate catheter segment, and the proximal drive catheter segment from the distal end of the intravascular thrombus aspiration catheter to the proximal end of the intravascular thrombus aspiration catheter. A more detailed explanation is given below in conjunction with the illustrated diagram.

[0033] Figure 1 A schematic diagram of an intravascular thrombus aspiration catheter according to some embodiments of the present disclosure is shown. In the illustrated embodiment, the intravascular thrombus aspiration catheter 100 includes: an inner flow channel, a distal aspiration catheter segment 110, an intermediate catheter segment 120, and a proximal drive catheter segment 130. Preferably, the inner flow channel of the intravascular thrombus aspiration catheter 100 is an internal circulation pipeline of the intravascular thrombus aspiration catheter 100. For example, the inner flow channel can start from the suction inlet 112 at the distal end of the intravascular thrombus aspiration catheter 100, through the inner flow channel of the distal aspiration catheter segment 110 of the intravascular thrombus aspiration catheter 100, through the inner flow channel of the intermediate catheter segment 120, and then through the inner flow channel of the proximal drive catheter segment 130, until the outflow window 133 at the proximal end of the intravascular thrombus aspiration catheter 100, so that the inner flow channel can sequentially connect the interiors of the distal aspiration catheter segment 110, the intermediate catheter segment 120, and the proximal drive catheter segment 130. It should be noted that the inner flow channel of the intravascular thrombus aspiration catheter 100 is connected to the aspiration inlet 112 and the outflow window 133. In order to enable the intravascular thrombus aspiration catheter 100 to filter or intercept thrombi in the blood, preferably, the intravascular thrombus aspiration catheter 100 further includes a filter 170, which is arranged outside the outflow window 133 and covers the outflow window 133, such as Figure 1 In addition, Figure 1 The figure also shows the location where the thrombus 140 is gathered, and the filter hole 171 is shown. In the exemplary embodiment of the figure, the filter part is designed at the rear end of the impeller (that is, closer to the proximal end than the impeller). This structure is conducive to increasing the blood flow rate during the suction process, reducing the impeller load, and thus reducing adverse events caused by heavy load and high heat generation. In addition, since the filter 170 is coated on the outside of the intravascular thrombus suction catheter 100, it can collect and gather more thrombi.

[0034] It should be noted that how the impeller drives the intravascular thrombus aspiration catheter 100 to perform aspiration will be described below through some embodiments. In some embodiments, the proximal driving catheter segment 130 in the intravascular thrombus aspiration catheter 100 also includes a flexible driving shaft and a sheath. The flexible driving shaft is arranged inside the proximal driving catheter segment 130, and the sheath is arranged on the outside of the flexible driving shaft. The proximal driving catheter segment 130 is connected to an extracorporeal motor through the flexible driving shaft and the sheath. The extracorporeal motor can drive the impeller 132 to rotate (high-speed rotation), so that the blood and thrombus in the inner flow channel of the intravascular thrombus aspiration catheter 100 enter the inner flow channel from the suction inlet 112 and flow toward the outflow window 133, and finally flow out from the outflow window 133.

[0035] In addition, in addition to disposing the filter part outside the intravascular thrombus aspiration catheter 100, the filter part can also be disposed inside the intravascular thrombus aspiration catheter 100. The following is an explanation with reference to the accompanying drawings.

[0036] Figure 2 Schematic diagrams of intravascular thrombus aspiration catheters according to other embodiments of the present disclosure are shown. In this exemplary embodiment, the intravascular thrombus aspiration catheter 200 includes: an inner flow channel, a distal aspiration catheter segment 210, an intermediate catheter segment 220, and a proximal drive catheter segment 230. Preferably, the inner flow channel of the intravascular thrombus aspiration catheter 200 is an internal circulation pipeline of the intravascular thrombus aspiration catheter 200. For example, the inner flow channel can start from the suction inlet 212 at the distal end of the intravascular thrombus aspiration catheter 200, through the inner flow channel of the distal aspiration catheter segment 210 of the intravascular thrombus aspiration catheter 200, through the inner flow channel of the intermediate catheter segment 220, and then through the inner flow channel of the proximal drive catheter segment 230, until the outflow window 233 at the proximal end of the intravascular thrombus aspiration catheter 200, so that the inner flow channel can sequentially connect the interiors of the distal aspiration catheter segment 210, the intermediate catheter segment 220, and the proximal drive catheter segment 230. It should be noted that the inner flow channel of the intravascular thrombus aspiration catheter 200 is connected to the aspiration inlet 212 and the outflow window 233. In order to enable the intravascular thrombus aspiration catheter 200 to filter or intercept thrombi in the blood, preferably, the intravascular thrombus aspiration catheter 200 further includes a filter 270, and the filter 270 is arranged between the impeller 232 of the inner flow channel and the outflow window 233, as shown in FIG. Figure 2 Similarly, Figure 2 The location where the thrombus 140 is gathered is also shown. Placing the filter 270 between the impeller and the outflow window of the inner flow channel is also beneficial to increase the blood flow rate during the suction process, reduce the impeller load, and thus reduce adverse events caused by heavy load and high heat generation.

[0037] In some embodiments, in order to enhance the toughness of the filter, the filter can be made of metal nickel titanium material or polymer material. Further, in some embodiments, part of the filter is composed of filter holes, or the entire filter is composed of filter holes, and the diameter of the filter holes is 0.1um to 500um. The diameter of the filter holes in the filter is set at 0.1um to 500um, thereby allowing blood to flow through and effectively intercepting most of the thrombus; and filter holes can also be set in part (or all) of the filter to achieve the function of filtering blood from thrombus.

[0038] Preferably, in some embodiments, when the filter screen is disposed outside the outflow window and covers the outflow window, the filter screen is constructed to be made of a polymer TPU material.

[0039] Preferably, in some embodiments, when the filter screen is disposed between the impeller and the outflow window of the inner flow channel, the filter screen is constructed to be made of a high molecular weight PLA material.

[0040] Further, in Figure 2 In an exemplary embodiment, that is, when the filter screen 270 is disposed between the impeller 232 and the outflow window 233 of the inner flow channel, a flow support structure 232-1 may be provided at the distal end of the impeller near the intravascular thrombus aspiration catheter 200, and the flow support structure 232-1 includes a blood channel 232-3 and an inner support frame 232-2. In some embodiments, the inner support frame 232-2 may include a plurality of support arms, the plurality of support arms are connected to the inner wall of the intravascular thrombus aspiration catheter 200, and the inner support frame 232-2 extends a distance along the axial direction of the intravascular thrombus aspiration catheter 200. Further, in some embodiments, the blood channel 232-3 is disposed between the support arms of the inner support frame 232-2 and extends along the axial direction of the intravascular thrombus aspiration catheter 200. In this way, a flow support structure 232-1 is provided at the distal end of the impeller 232 near the intravascular thrombus aspiration catheter 200. The inner support frame 232-2 of the flow support structure 232-1 can strengthen the support of the tube section, and the blood channel 232-3 can ensure that the blood to be aspirated and filtered can flow smoothly to the filter 270 or the filtering part.

[0041] Furthermore, in some embodiments, the inner flow channel is provided with a one-way valve, which is provided between the suction inlet and the impeller. In this way, the collected and accumulated thrombus can be effectively prevented from flowing back into the blood vessel with the backflow of blood when the blood suction stops suddenly (for example, the impeller stops suddenly); and the one-way valve provided between the suction inlet and the impeller can prevent the formation of a blood retention area in the inner flow channel of the intravascular thrombus suction catheter, thereby preventing the formation of new thrombus.

[0042] It should be noted that in some embodiments, the filter is configured as a convex filter, which is configured as a structure with a center protruding forward, wherein the structure with a center protruding forward refers to a structure in which the central protruding portion of the convex filter is protruding toward the distal end of the intravascular thrombus aspiration catheter. Further, in some embodiments, the convex filter is configured to have a circular radial cross-section, and the cross-sectional diameter of the circle increases continuously from the distal end to the proximal end. The convex filter is configured as a structure with a center protruding forward, so that when blood with thrombus passes through the filter, the thrombus is easily moved toward the circumference of the filter and aggregated, so that the thrombus will be closer to the edge of the inner cavity wall rather than the central part of the filter. Accumulation; thus, when a certain amount of thrombus is collected, since the middle part is not affected by the aggregation of thrombus, a good blood passage rate can still be guaranteed.

[0043] It should be noted that in some embodiments, the convex filter is configured as a convex nickel-titanium filter, so that the convex filter has a certain rigidity, ensuring that the filter faces the distal end (i.e., convex), and will not be easily pushed into a protruding structure toward the proximal end by blood flow and other reasons. It should be noted that in some embodiments, the filter can also protrude toward the proximal end, but the filter arranged in this way is likely to gather the intercepted thrombus in the central area of ​​the filter, causing poor blood circulation in the central area of ​​the filter, thereby affecting the overall suction capacity of the intravascular thrombus aspiration catheter.

[0044] It should be noted that in some embodiments, the filter is constructed as a double-layer structure, which includes a distal filter layer and a proximal filter layer, wherein the filter pore size of the filter of the distal filter layer is larger than the filter pore size of the filter of the proximal filter layer. Therefore, in this embodiment, the filter of the distal filter layer can effectively intercept relatively large thrombi, while the filter of the proximal filter layer can intercept partially detached and broken thrombi (i.e., relatively small thrombi), so that the double-layer filter setting can improve the efficiency of thrombus interception.

[0045] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

[0046] The above description is only an optional embodiment of the present disclosure and is not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. An intravascular thrombus aspiration catheter, comprising: An inner flow channel, a distal suction catheter segment, an intermediate catheter segment and a proximal drive catheter segment, wherein the inner flow channel sequentially connects the distal suction catheter segment, the intermediate catheter segment and the proximal drive catheter segment from the distal end to the proximal end of the intravascular thrombus suction catheter, It is characterized in that The intravascular thrombus aspiration catheter further comprises an aspiration inlet and an outflow window, and the inner flow channel communicates the aspiration inlet and the outflow window; The inner flow channel is provided with an impeller; The suction inlet, the impeller and the outflow window are sequentially arranged from the distal end to the proximal end of the intravascular thrombus suction catheter. The intravascular thrombus aspiration catheter further includes a filter; The filter is arranged between the impeller and the outflow window of the inner flow channel, or The filter screen is arranged outside the outflow window and covers the outflow window.

2. The intravascular thrombus aspiration catheter according to claim 1, characterized in that: The proximal drive catheter segment also includes a flexible drive shaft and a sheath, wherein the flexible drive shaft is arranged inside the proximal drive catheter segment, and the sheath is arranged outside the flexible drive shaft. The proximal drive catheter segment is connected to an extracorporeal motor via the flexible drive shaft and the sheath, and the extracorporeal motor drives the impeller to rotate so that the blood and thrombus in the inner flow channel of the intravascular thrombus aspiration catheter enter the inner flow channel from the suction inlet and flow toward the outflow window.

3. The intravascular thrombus aspiration catheter according to claim 1, characterized in that: The filter screen is configured such that the diameter of the filter holes is 0.1 micron to 500 microns.

4. The intravascular thrombus aspiration catheter according to claim 1, characterized in that: The filter screen is constructed to consist of partial filter holes or all filter holes.

5. The intravascular thrombus aspiration catheter according to claim 1, characterized in that: The filter screen is constructed into a double-layer structure, which includes a distal filter screen layer and a proximal filter screen layer, wherein the filter screen of the distal filter screen layer has a filter pore size larger than the filter screen of the proximal filter screen layer.

6. The intravascular thrombus aspiration catheter according to claim 1, characterized in that: When the filter is disposed between the impeller and the outflow window of the inner flow channel, The filter is configured as a forward convex filter, and the forward convex filter is constructed as a structure with a center convex forward. The center convex forward structure means that the central convex part of the forward convex filter is a structure that convexes toward the distal end of the intravascular thrombus aspiration catheter.

7. The intravascular thrombus aspiration catheter according to claim 1, characterized in that: When the filter is disposed between the impeller and the outflow window of the inner flow channel, The impeller is provided with a flow support structure near the distal end of the intravascular thrombus aspiration catheter, and the flow support structure includes a blood channel and an inner support frame.

8. The intravascular thrombus aspiration catheter according to claim 7, characterized in that: The inner support frame includes a plurality of support arms, the plurality of support arms are connected to the inner wall of the intravascular thrombus aspiration catheter, and the inner support frame extends a distance along the axial direction of the intravascular thrombus aspiration catheter.

9. The intravascular thrombus aspiration catheter according to claim 8, characterized in that: The blood channel is disposed between the support arms of the inner support frame and extends along the axial direction of the intravascular thrombus aspiration catheter.

10. The intravascular thrombus aspiration catheter according to claim 1, characterized in that: The inner flow passage is provided with a one-way valve disposed between the suction inlet and the impeller.

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