Thrombus filter device
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANGHAI BLUESAIL BOAO MEDICAL TECH CO LTD
- Filing Date
- 2021-11-19
- Publication Date
- 2026-07-14
Smart Images
Figure CN116138922B_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to a thrombus filtration device. Background Technology
[0002] Transcatheter aortic valve replacement (TAVR) is a treatment for patients with moderate to severe aortic stenosis. With the increasing indications for TVR, attention to intraoperative adverse events and complications is also growing, with stroke being one of the most serious complications. Currently available transcatheter aortic valve replacement devices have an average stroke rate of 2%-6% within 30 days post-procedure; therefore, brain protection is one of the urgent issues to be addressed in TVR research.
[0003] Stroke is divided into ischemic stroke and hemorrhagic stroke. Ischemic stroke is caused by an embolus flowing into the blood vessels of the brain and blocking them, resulting in local blood vessel ischemia. Stroke has a very high mortality rate and neurological morbidity. Ischemic stroke accounts for 60%-70% of all stroke patients and mainly includes cerebral thrombosis and cerebral embolism.
[0004] Cerebral embolism is caused by emboli in the blood vessels supplying the brain, leading to arterial embolism. These emboli mainly originate from acute thrombosis caused by instruments in the aortic arch or aortic valve, as well as tissue detachment from the aortic arch wall, arterial wall, atherosclerotic plaques, valve leaflet tissue, cations, calcified deposits, etc. The procedure and instruments used in transcatheter aortic valve replacement surgery are among the main causes of arterial embolism. Current technologies employ a series of measures to reduce the risk of stroke associated with transcatheter aortic valve replacement surgery, including perioperative anticoagulation therapy, minimizing manipulation of the aortic arch and aortic valve position, and using cerebral embolism protection devices. Summary of the Invention
[0005] At least one embodiment of this disclosure provides a thrombus filtration device, including a frame, a filter membrane, and a separator. The frame includes a first frame portion and a second frame portion, the first frame portion being configured to unfold to form an annular distal opening, and the second frame portion being configured to unfold to form an annular proximal opening. The filter membrane is disposed on and covers the frame, such that the filter membrane can be supported by the frame to unfold into a tubular structure. The separator extends from the proximal opening toward the distal opening and is located within the tubular structure. The separator is configured to divide the inner cavity of the tubular structure near the proximal opening into a collection region and a channel region. The filter membrane corresponding to the collection region is configured to be stepped along the axial direction of the thrombus filtration device.
[0006] For example, in a thrombus filtration device provided in at least one embodiment of this disclosure, the stepped shape includes a plurality of serrations, which are arranged along the axial and circumferential directions of the thrombus filtration device on the filter membrane of the collection area.
[0007] For example, in a thrombus filtration device provided in at least one embodiment of this disclosure, the tubular structure is an arc-shaped tube, and the filter membrane includes a first part and a second part connected to each other. The first part is configured to unfold to form an arc-shaped back tube wall with a first curved surface, and the second part is configured to unfold to form an arc-shaped inner tube wall with a second curved surface, so that the arc-shaped tube has opposing arc-shaped back tube walls and arc-shaped inner tube walls.
[0008] For example, in a thrombus filtration device provided in at least one embodiment of this disclosure, the separator includes a curved isolation baffle, one side of which is connected to a portion of the proximal opening along its extension direction.
[0009] For example, in a thrombus filtration device provided in at least one embodiment of this disclosure, the isolation baffle includes a separation frame body and a multilayer membrane structure covering the separation frame body, wherein the multilayer membrane structure is a porous structure.
[0010] For example, in a thrombus filtration device provided in at least one embodiment of this disclosure, the filter membrane corresponding to the collection area is configured as a multilayer membrane structure, and the multilayer membrane structure is a porous structure.
[0011] For example, in a thrombus filtration device provided in at least one embodiment of this disclosure, the multilayer membrane structure is a double-layer membrane, comprising a first membrane and a second membrane. The first membrane is located on the side of the second membrane closer to the collection area, and the pore size of the first membrane is larger than that of the second membrane.
[0012] For example, in a thrombus filtration device provided in at least one embodiment of this disclosure, there is a first interlayer gap between the first membrane and the second membrane, and the first interlayer gap is 2mm-5mm.
[0013] For example, in a thrombus filtration device provided in at least one embodiment of this disclosure, the pore size of the first membrane is in the range of 100 μm to 200 μm, and the pore size of the second membrane is in the range of 50 μm to 70 μm.
[0014] For example, in a thrombus filtration device provided in at least one embodiment of this disclosure, the isolation baffle is connected to the two ends of the first curved surface and the second curved surface respectively, so that the inner cavity of the arc-shaped tube is divided into a collection area surrounded by the second curved surface and the separator and a channel area surrounded by the first curved surface and the separator.
[0015] For example, in a thrombus filtration device provided in at least one embodiment of this disclosure, the separating element is funnel-shaped and includes a separating frame body and a multi-layered mesh sleeved on the separating frame body. The separating frame body includes a first end that can be unfolded into an annular shape and a second end that can be unfolded into an annular shape, the radial dimension of the first end is larger than the radial dimension of the second end, and the first end is connected to a proximal opening.
[0016] For example, in a thrombus filtration device provided in at least one embodiment of this disclosure, the multilayer mesh is a double-layer mesh, which includes a first mesh and a second mesh. The first mesh is located on the side of the second mesh closer to the collection area, and the pore size of the first mesh is larger than that of the second mesh.
[0017] For example, in a thrombus filtration device provided in at least one embodiment of this disclosure, there is a second interlayer gap between the first membrane and the second membrane, and the second interlayer gap is 2mm-5mm.
[0018] For example, in a thrombus filtration device provided in at least one embodiment of this disclosure, the pore size of the first membrane ranges from 100 μm to 200 μm, and the pore size of the second membrane ranges from 50 μm to 70 μm.
[0019] Compared with the prior art, the beneficial effects of at least one embodiment of this disclosure include: the thrombus filtration device of this disclosure incorporates a separation design within the filter membrane near the proximal opening, dividing the inner cavity of the thrombus filtration device into a collection area for filtering blood and collecting thrombi, and a channel area for the sheath of the delivery system to pass through. Since the filter membrane corresponding to the collection area has a stepped proximal filter membrane structure, it can prevent thrombi from accumulating on the filter membrane surface, avoid clogging of the membrane pores, prevent an increase in transmembrane pressure differential, and facilitate blood flow. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 A front view of a thrombus filtration device with a stepped filter membrane provided for some embodiments of this disclosure;
[0022] Figure 2 A front view of a curved, separable component provided for some embodiments of this disclosure;
[0023] Figure 3 A partial schematic diagram of the proximal opening of a curved separator provided for some embodiments of this disclosure;
[0024] Figure 4 A front view of a funnel-shaped separator provided for some embodiments of this disclosure. Detailed Implementation
[0025] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.
[0026] Unless otherwise defined, all terms (including technical and scientific terms) used in embodiments of this disclosure shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should also be understood that terms such as those defined in a common dictionary shall be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as being interpreted in an idealized or highly formalized sense, unless expressly defined in embodiments of this disclosure.
[0027] The terms “center,” “upper,” “lower,” “left,” “right,” “vertical,” and “horizontal” used in the embodiments of this disclosure indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this embodiment is usually placed in during use. They are only for the convenience of describing the embodiments of this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this disclosure.
[0028] The terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "an," "a," or "the" do not indicate a quantity limitation, but rather indicate the presence of at least one. Similarly, terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.
[0029] Embolism protection devices (such as cerebral embolism protection devices) are used to block or collect emboli generated during transcatheter aortic valve replacement surgery, preventing them from entering the brain (cerebral circulation) or other parts of the body (systemic circulation) through the aortic arch arteries, causing complications such as stroke, neurocognitive decline, pulmonary embolism, and lower extremity arteriovenous embolism. This embolism protection device can also be called a thrombus filtering device.
[0030] The inventors of this disclosure have discovered that in some prior art solutions, the filter membrane of a thrombus filtration device has a porous structure to filter and block emboli in the blood whose pore size is larger than the membrane pore diameter, and these emboli are collected at the proximal end of the thrombus filtration device. For example, the proximal end of the thrombus filtration device can be a funnel-like design, but the emboli collected at this funnel-shaped proximal end tend to accumulate and block the membrane pores of the filter membrane, making it difficult for blood to flow out from the membrane pores at the proximal end of the filter membrane.
[0031] The inventors of this disclosure have discovered that more than 99% of emboli in a patient's body have a diameter greater than 0.15 mm, and more than 91% have a diameter greater than 0.5 mm. Meanwhile, the pore size of a membrane is usually around 50 μm to 200 μm. More than 98% of emboli are thrombi or intravascular tissue. These emboli adhere to the surface of the filter membrane, blocking the permeation of various cells in the blood.
[0032] At least one embodiment of this disclosure provides a thrombus filtration device, including a frame, a filter membrane, and a separator. The frame includes a first frame portion and a second frame portion, the first frame portion being configured to unfold to form an annular distal opening, and the second frame portion being configured to unfold to form an annular proximal opening. The filter membrane is disposed on and covers the frame, such that the filter membrane can be supported by the frame to unfold into a tubular structure. The separator extends from the proximal opening toward the distal opening and is located within the tubular structure. The separator is configured to divide the inner cavity of the tubular structure near the proximal opening into a collection region and a channel region, wherein the filter membrane corresponding to the collection region is stepped along the axial direction of the thrombus filtration device.
[0033] The thrombus filtration device of the above embodiments of this disclosure incorporates a separation design within the filter membrane near the proximal opening. This divides the inner cavity of the thrombus filtration device into a collection area for collecting and filtering thrombi and a channel area for the sheath of the delivery system to pass through. Since the filter membrane corresponding to the collection area has a stepped proximal filter membrane structure, it prevents thrombi from accumulating on the filter membrane surface, avoids clogging of the membrane pores, prevents increased transmembrane pressure differential, and facilitates blood flow.
[0034] The embodiments and examples of this disclosure will now be described in detail with reference to the accompanying drawings.
[0035] For the sake of clarity and conciseness, the following description mainly uses the aortic arch 400 as an example. However, this disclosure does not limit the types of blood vessels to which it applies. This disclosure can also be applied to other blood vessels that require embolization protection. The embodiments of this disclosure do not limit or elaborate on this.
[0036] For example, regarding the definition of direction, for ease of description, at least one embodiment of this disclosure refers to the side closer to the operator (surgeon) as the proximal end or proximal side and the side farther from the operator (surgeon) as the distal end or distal side. However, the distal end and proximal end in this disclosure are relative orientations of the elements or actions relative to each other, and this is not restrictive.
[0037] Figure 1 This is a front view of a thrombus filtration device with a stepped filter membrane provided in some embodiments of this disclosure. Figure 1 The image shows the frame 100 of the thrombus filtering device placed inside a blood vessel, for example, the aortic arch 600, and in an extended state.
[0038] For example, such as Figure 1 As shown, at least one embodiment of this disclosure provides a thrombus filtration device 1000 including a frame 100, a filter membrane 200, and a separator 300. The frame 100 includes a first frame portion and a second frame portion, the first frame portion being configured to unfold to form an annular distal opening 130, and the second frame portion being configured to unfold to form an annular proximal opening 140.
[0039] In some examples, frame 100 includes a distal guidewire 110 and a proximal guidewire 120. For example, a first frame portion is at least a portion of the distal guidewire 110, i.e., at least a portion of the distal guidewire 110 is supported distally at the aortic arch 400 to unfold and form an annular distal opening 130. For example, a second frame portion is at least a portion of the proximal guidewire 120, i.e., at least a portion of the proximal guidewire 120 is supported proximally at the aortic arch 400 to unfold and form an annular proximal opening 140. A filter membrane 200 is disposed on and covers frame 100, frame 100 being configured to support filter membrane 200. Filter membrane 200 has a porous structure for filtering blood and preventing emboli from passing through.
[0040] This is merely an example. The structure and construction of the frame 100 in the embodiments of this disclosure are not limited to the guide wire shape described above. As long as it can satisfy the formation of proximal opening and distal opening and can support the filter membrane 200, it will not be described in detail here.
[0041] In some examples, the filter membrane 200 is fixedly connected to the outside of the frame 100 and wraps around the frame 100 to conform to the arch wall 410. As another example, the filter membrane 200 is fixedly connected to the inside of the frame 100 and adheres to the frame 100 to conform to the arch wall 410. For example, the filter membrane 200 can be fixed to the frame 100 in various ways. For example, the filter membrane 200 is attached to the frame 100 by means of adhesive or sewing. This is merely exemplary and is not intended to limit the scope of this disclosure.
[0042] In some examples, the distal opening 130 and / or proximal opening 140 of the annulus are substantially annular. Here, the annulus is not limited to a circular ring, but can also be an elliptical, olive-shaped, teardrop-shaped, or other regular or irregular closed shape enclosed by arcs, and is not limited to a planar closed shape, but can also be a closed shape enclosed by arcs that are not on the same plane.
[0043] For example, such as Figure 1 As shown, the thrombus filtering device 1000 is anchored to the aortic arch 400 by applying a radial force to the arch wall 410 of the aortic arch 400, creating a good seal between the device and the vessel wall of the aortic arch 400, preventing blood or emboli from flowing through the outer edge of the thrombus filtering device 1000. Blood and emboli in the blood simultaneously flow into the thrombus filtering device 1000 through the distal opening 130. The filter membrane 200 directly blocks emboli in the blood from entering the cerebral artery of the aortic arch 400. Subsequently, the proximal end of the thrombus filtering device 1000 (e.g., collection area A1 below) captures the emboli, and finally, the emboli are removed from the patient along with the thrombus filtering device 1000.
[0044] In some examples, the filter membrane 200 presents a tubular structure that matches blood vessels when unfolded.
[0045] For example, such as Figure 1 As shown, the blood vessel is the aortic arch 400. The filter membrane 200, supported by the frame 100, forms a tubular structure called an arcuate tube when unfolded. This filter membrane 200 presents an arcuate tube that matches the aortic arch 400 when unfolded. Correspondingly, the extension path of the frame 100 also needs to be able to support the filter membrane 200 to form the corresponding shape.
[0046] For example, during the delivery of the thrombus-releasing filter device, the release can be observed and operated via angiography to ensure that the arcuate structure formed by the expansion of the filter membrane 200 is aligned with the bending direction of the aortic arch 400.
[0047] For example, such as Figure 1 As shown, the filter membrane 200 includes a first portion 210 and a second portion 220 connected to each other. The first portion 210 is configured to unfold to form a bow-back side tube wall having a first curved surface S1, and the second portion 220 is configured to unfold to form a bow-inside tube wall having a second curved surface S2, such that the bow-shaped tube has opposing bow-back side tube walls and bow-inside tube walls.
[0048] It should be noted that the tubular structure of the embodiments of this disclosure is not limited to the arched tube that matches the aortic arch 400 as described above. This is only an example. It can also be a tubular structure that matches the shape of other blood vessels, which will not be elaborated here.
[0049] It should also be noted that, in describing the technical solution of the thrombus filtration device in the above embodiments of this disclosure, it is divided into elements or objects for performing corresponding functions. However, those skilled in the art will understand that the functions performed by each element or object can be performed under the above-described division or under other division methods, which does not limit the scope of protection of this disclosure. For example, the first part 210 and the second part 220 of the filter membrane 200 can be two different parts of an integral membrane structure, but this disclosure divides the filter membrane 200 into two parts for illustrative purposes.
[0050] For example, such as Figure 1 As shown, the thrombus filtration device 1000 also includes a sheath 600, which may also be referred to as an embolization protection sheath. The sheath 600 is configured to provide space for accommodating the frame 100 and the filter membrane 200. For example, the sheath 600 may be configured to place and deliver the compressed frame 100 and filter membrane 200, which are subsequently pushed out of the sheath 600 for release and expansion. After the treatment procedure is completed, the frame 100 and filter membrane 200 of the thrombus filtration device 1000 may also be retrieved within the sheath 600; that is, the sheath 600 is also configured to allow the retrieved, expanded frame 100 of the thrombus filtration device 1000 to pass through.
[0051] In some examples, the frame 100 and filter membrane 200, after being released from the sheath 600, can be restored to, for example, an arched shape and abut against the arch wall 410 of the aortic arch 400.
[0052] In some examples, the thrombus filtering device 1000 can also be used with a therapeutic device delivery system 2000, such as a TAVI delivery system. For example, as Figure 1 As shown, the TAVI delivery system includes a sheath 700, which may also be referred to as a TAVI device sheath. The sheath 700 can pass through an opening in the proximal opening 140 into the aortic arch 400. For example, after the thrombus filtering device is deployed, the sheath 700 passes through the opening in the proximal opening 140 into the filter membrane 200. An artificial prosthesis (not shown), such as an artificial heart valve, is placed inside the sheath 700, which is configured to deliver and deploy the artificial heart valve to a corresponding location within the body.
[0053] Therefore, the thrombus filtering device 1000 of the present disclosure can be used as a filter protector during TAVI surgery, that is, as an embolism protection device. It should be noted that the thrombus filtering device 1000 of the present disclosure is not limited to use as a protective filter in TAVI / TAVR surgery, but can also be used in other cardiac surgeries of the left ventricular system, such as left atrial appendage occlusion, atrial fibrillation ablation, mitral valve repair or mitral valve replacement, or other cardiac surgeries with or without pumps. For example, with appropriate adjustments, the thrombus filtering device 1000 can also be used to leave the device in the aorta after cardiac surgery. The embodiments of the present disclosure do not limit the applicable scenarios of the thrombus filtering device 1000, and will not be exhaustively described here.
[0054] It should also be noted that the above embodiments of this disclosure... Figure 1 The separator of the thrombus filtering device is illustrated using a curved isolation baffle as an example, but this is merely an illustration and may also represent, for example, the following components. Figure 4 Specific examples, namely Figure 4 Examples can also be used with Figure 1 The thrombus filtration device is described in conjunction with this.
[0055] For example, such as Figure 1 As shown, the separator 300 is configured to extend from the proximal opening 140 toward the distal opening 130 and is located within the arcuate tube. The separator 300 is configured to divide the inner cavity of the arcuate tube near the proximal opening 140 into a collection area A1 and a channel area A2. The filter membrane 200a corresponding to the collection area A1 is stepped along the axial direction of the thrombus filtration device. For ease of understanding, in Figure 1 The double arrows indicate the direction along the axial direction of the thrombus filtering device. Collection area A1 is configured to filter blood and collect emboli. Channel area A2 is configured as a channel for the sheath 700 to pass through.
[0056] In the above embodiment, the filter membrane 200a corresponding to the collection area A1 is designed in a stepped shape, which can change the way emboli accumulate. For example, it allows emboli with low viscosity to be carried towards the collection area A1 with the blood flow, thus preventing emboli from accumulating on the surface of the filter membrane 200, avoiding blockage of the membrane pores, facilitating blood flow, and improving emboli collection efficiency. In addition, since the proximal opening forms a stepped filter bag structure with openings, the space occupied by the filter membrane in the radial direction is reduced, reducing the resistance to recovery to the sheath 600, and enabling smooth multiple recovery and release of the thrombus filtration device.
[0057] In some examples, the stepped shape of the filter membrane 200a corresponding to collection area A1 is a non-smooth surface formed by alternating concave and convex surfaces. It should be noted that the stepped shape of the filter membrane 200a corresponding to collection area A1 can be regular or irregular, as long as the filter membrane 200a corresponding to collection area A1 has local areas with convex and concave sides to enhance the interception effect. This will not be elaborated further here.
[0058] In some examples, as the curvature of the slope design of the filter membrane 200a corresponding to the collection area A1 increases, the degree of curvature of the stepped concave and convex surfaces can also gradually increase, which is beneficial to the collection efficiency of emboli in the closed collection area A1.
[0059] For example, the stepped structure of the filter membrane 200a corresponding to collection area A1 includes multiple serrations, which are arranged along the axial and circumferential directions of the thrombus filtration device on the filter membrane corresponding to the collection area. Thus, the high curvature of the serrations greatly improves the thrombus collection efficiency.
[0060] Figure 2 A front view of a curved separator provided for some embodiments of this disclosure. Figure 3 This is a partial schematic diagram of a proximal opening of a curved separator provided for some embodiments of this disclosure. Figure 4 A front view of a funnel-shaped separator provided for some embodiments of this disclosure.
[0061] For example, such as Figure 2 As shown, the separator 300 includes a curved isolation baffle 310, one side of which is connected to a portion of the proximal opening 140 along its extension direction. For example, the isolation baffle 310 is connected to the proximal opening 140 by welding. This is merely exemplary and not a limitation of this disclosure. Thus, embodiments of this disclosure, by using a curved isolation baffle near the proximal opening, can divide the inner lumen of the unfolded arcuate tube into a collection area A1 and a channel area A2, respectively used to filter blood collection plugs and allow the sheath 700 to pass smoothly.
[0062] In some examples, the curved isolation baffle 310 is adapted to the aortic arch 400, with its center point located on the dorsal side of the arch of the aortic tube. For example, the curvature of the isolation baffle 310 varies at different positions along its extension direction. The overall curvature of the surface must ensure that the sheath 700 can pass through smoothly while minimizing leakage of emboli from the channel area A2. That is, the overall curvature of the surface cannot be too large or too small, and it must also prevent the thrombus filtering device from twisting or flipping due to an inappropriate curvature. It should be noted that the embodiments of this disclosure do not limit the curvature of the surface; it can be freely adjusted according to actual conditions, which will not be elaborated here. In other examples, the center point of the curved surface is located on the inner side of the arch of the aortic tube, and the embodiments of this disclosure do not impose this limitation.
[0063] For example, such as Figure 2 As shown, the isolation baffle 310 includes a separation frame body 311 and a multilayer membrane structure 312 covering the separation frame body 311. The multilayer membrane structure 312 is a porous structure. In this way, compared with the existing single-layer membrane design, the use of a porous membrane structure can avoid emboli clogging the membrane pores and avoid increasing the transmembrane pressure difference.
[0064] In some examples, the multilayer membrane structure 312 is a bilayer membrane, comprising a first membrane and a second membrane. The first membrane is located on the side of the second membrane closer to the collection region A1, and the pore size of the first membrane is larger than that of the second membrane. Thus, the first membrane, which is the first layer of the bilayer membrane to contact the embolus in the collection region A1, is a large-pore membrane, used to intercept large emboli and allow small emboli and blood to pass through. The interlayer gaps of the bilayer membrane block large emboli and leave channels for small particles and blood. When blood and small particles flow forward to the small-pore second membrane, the small-pore membrane intercepts the small particles and allows blood to pass through, preventing the embolus from completely blocking the membrane surface and avoiding an increase in transmembrane pressure difference.
[0065] In some examples, there is a first interlayer gap between the first and second membrane layers, which is 2mm-5mm. This helps to prevent emboli from clogging the membrane pores and avoid increasing the transmembrane pressure difference.
[0066] In some examples, the pore size of the first membrane ranges from 100 μm to 200 μm, and the pore size of the second membrane ranges from 50 μm to 70 μm. This allows the thrombus filtration device 1000 to filter and collect over 99% of thrombus particles from the patient's body.
[0067] In some examples, the filter membrane 200a corresponding to the collection area A1 can adopt a multilayer membrane structure. For example, the filter membrane 200a corresponding to the collection area A1 can adopt a double-layer membrane structure. This can also avoid emboli blocking the membrane pores, avoid increasing the transmembrane pressure difference, and facilitate blood flow. The multilayer membrane structure can refer to the multilayer membrane structure 312 above, which will not be repeated here.
[0068] In some examples, the entire filter membrane 200 can adopt a multilayer membrane structure, such as a double-layer membrane structure. The embodiments disclosed herein are not limited to this; for example, it is not limited to the filter membrane 200a corresponding to the collection region A1. A multilayer membrane structure can also be provided at the aortic arch 400 near the cerebral blood vessel, which can similarly achieve the effect of preventing emboli from clogging the pores and avoiding increasing the transmembrane pressure difference. The multilayer membrane structure here can refer to the multilayer membrane structure 312 described above, and will not be repeated here.
[0069] It should be noted that the entire second part 220 of the filter membrane 200 in the embodiments of this disclosure (i.e., the inner wall of the tube corresponding to the bow) can be set in a stepped shape, and is not limited to only the filter membrane 200a corresponding to the collection area A1 being stepped. This can also further prevent plugs from accumulating on the surface of the filter membrane to a certain extent and avoid the membrane pores of the filter membrane from being blocked.
[0070] For example, such as Figure 1 and Figure 3 As shown, the isolation baffle 310 is connected to the two ends of the first curved surface S1 and the second curved surface S2 respectively, that is, the two side edges of the isolation baffle 310 are connected to the edge of the filter membrane 200, so that the inner cavity of the bow-shaped tube is divided into a collection area A1 enclosed by the second curved surface S2 and the separator 300 and a channel area A2 enclosed by the first curved surface S1 and the separator 300. For example, the width of the isolation baffle 310 is not less than the diameter of the corresponding position of the bow-shaped tube, so as to prevent the plug from leaking out from the edge.
[0071] In some examples, the separation frame body 311 of the isolation baffle 310 can be a porous plate or a non-porous plate. The embodiments of this disclosure do not limit this, as long as the separation frame body 311 has a multilayer membrane structure 312 capable of filtering emboli.
[0072] In some examples, the separation frame body 311 of the isolation baffle 310 is made of nickel-titanium wire, for example, the isolation baffle 310 is formed by covering the nickel-titanium wire with a double-layer film. This is merely exemplary and is not intended to limit the scope of this disclosure.
[0073] In some examples, the isolation baffle 310 has a curvature adapted to the portion of the bow tube near the proximal opening 140, allowing the sheath tube 700 to pass smoothly through the channel region A2. For example, as Figure 1As shown, the isolation baffle 310 does not completely divide the entire inner cavity of the arc-shaped tube into two sides. This depends on the extension length of the isolation baffle 310, and the extension length of the isolation baffle 310 can be determined according to the actual situation. For example, when the channel area A2 is for the sheath tube 700 to pass through, the diameter of the sheath tube 700 is designed to just block the opening of the channel area A2, so as to prevent the plug from leaking out during actual use.
[0074] For example, such as Figure 4 As shown, the separating element 300 is a funnel-shaped separating structure 320, which includes a separating frame body 321 and a multi-layered mesh 322 sleeved on the separating frame body 321. The separating frame body 321 has two opposing ends, which are annular with different radial dimensions, so that the multi-layered mesh 322 forms a funnel-shaped separating structure 320 when it is sleeved on the separating frame body 321. The area enclosed by the surface of the multi-layered mesh 322 and the arcuate tube is a collection area A1, used for filtering blood and collecting emboli. The hollow area of the funnel-shaped separating structure 320 is a channel area A2 for the sheath 700 to pass through. Thus, by using a funnel-shaped separating structure at the proximal opening, the inner cavity of the unfolded arcuate tube can be divided into a collection area and a channel area, which are used for filtering blood and collecting emboli and for the sheath 700 to pass through smoothly, respectively.
[0075] In some examples, the separation frame body 321 includes a first end 321a that can unfold into an annular shape and a second end 321b that can unfold into an annular shape. The radial dimension of the first end 321a of the separation frame body 321 is larger than the radial dimension of the second end 321b of the separation frame body 321; that is, the first end 321a of the separation frame body 321 is the large end and the second end 321b of the separation frame body 321 is the small end. The annular first end 321a is connected to the annular proximal opening 140. For example, the radial dimension of the annular second end 321b of the separation frame body 321 is slightly smaller than the diameter of the delivery sheath 700, which passes through the second end 321b and substantially seals the second end 321b of the separation frame body 321, so that the plug does not leak out from the second end 321b of the separation frame body 321.
[0076] For example, with Figure 4 Taking the illustrated orientation as an example, the separation structure 320 is inverted funnel-shaped, which not only easily divides the inner cavity of the thrombus filtering device into a collection area A1 and a channel area A2, but also closes the proximal opening 140 when the sheath 700 passes through the channel area A2, preventing emboli from leaking out of the funnel opening. This also prevents emboli from leaking out even after the sheath 700 is removed. Therefore, the inverted funnel-shaped separation structure 320 facilitates the operation of the sheath 700 and effectively filters and collects emboli.
[0077] It should be noted that the separation structure 320 can also be funnel-shaped, meaning the radial dimension of the first end of the separation frame body 321 near the proximal opening 140 is smaller than the radial dimension of the second end of the separation frame body 321 away from the proximal opening 140. This is acceptable as long as the sheath 700 can pass through the first end 321a and substantially seal the first end 321a of the separation frame body 321, preventing the plug from leaking out from the first end 321a. In this case, for example, in actual operation, to prevent some plugs from leaking out from the larger opening of the second end after the sheath 700 is removed, a recessed design can be added to the inner wall of the separation structure 320 to collect the plugs leaking from the larger opening of the second end. This is merely exemplary and not a limitation of this disclosure, and will not be elaborated further here.
[0078] In some examples, the separation frame body 321 of the separation structure 320 is made of nickel-titanium wire or other metal material; for example, the separation structure 320 is formed by covering a double-layer film onto a nickel-titanium wire. This is merely exemplary and is not intended to limit the scope of this disclosure.
[0079] In some examples, the multilayered retinal membrane 322 is a double-layered retinal membrane, comprising a first membrane and a second membrane. The first membrane is located on the side of the second membrane closer to the collection area A1, and the pore size of the first membrane is larger than that of the second membrane. Thus, the first membrane, which is the first to contact the collection area, is a large-pore membrane used to intercept large emboli, allowing small emboli and blood to pass through. The interlayer gaps of the double-layered retinal membrane block large emboli while leaving channels for small particles and blood. When blood and small particles flow forward to the small-pore second membrane, this small-pore membrane intercepts the small particles and allows blood to pass through, thereby preventing the emboli from completely blocking the membrane surface and avoiding an increase in transmembrane pressure difference.
[0080] In some examples, a second interlayer gap of 2mm-5mm exists between the first and second membrane layers. This helps to prevent emboli from clogging the membrane pores and avoid increasing the transmembrane pressure difference.
[0081] In some examples, the pore size of the first membrane ranges from 100 μm to 200 μm, and the pore size of the second membrane ranges from 50 μm to 70 μm. Thus, the thrombus filtration device 1000 can filter and collect more than 99% of thrombus particles from the patient's body.
[0082] For example, distal guidewire 110 and / or proximal guidewire 120 may comprise medical shape memory alloy materials and / or medical hyperelastic materials. For example, distal guidewire 110 and / or proximal guidewire 120 may comprise biodegradable polymers or biodegradable metallic materials.
[0083] For example, the filter membrane 200 is configured as a membrane having pores with uniform or non-uniform spacing. For example, the filter membrane 200 can be pre-shaped to form a predetermined shape.
[0084] For example, the filter membrane 200 comprises one or more of the following materials: polymer or metal. For example, the filter membrane 200 is made of a low-friction and flexible polymer or metal material.
[0085] For example, the polymer material of the filter membrane 200 includes one or more of the following: PEEK (polyether ether ketone), PU (polyurethane), PA (polyamide), PTFE (polytetrafluoroethylene), PE (polyethylene), PC (polycarbonate), PP (polypropylene), and PLA (polylactic acid). This is merely exemplary and is not intended to limit the scope of this disclosure.
[0086] For example, the metallic material of the filter membrane 200 includes one or more of the following: Ni-Ti (nickel-titanium) and 304 stainless steel. This is merely exemplary and is not intended to limit the scope of this disclosure.
[0087] The filter membrane 200 may also include other polymeric materials and / or other metallic materials, such as biodegradable polymeric materials or biodegradable metallic materials, which will not be elaborated here.
[0088] In some examples, the filter membrane 200 is provided with an antithrombotic coating. Thus, by applying the antithrombotic coating to the filter membrane 200, the coated membrane inhibits thrombin activity, achieving anticoagulation and ultimately preventing blood from clotting and clogging the membrane pores, thus avoiding an increase in transmembrane pressure gradient. For example, the antithrombotic coating may contain heparin.
[0089] In other examples, the outer surface of the filter membrane 200 may also be coated with a coating that reduces frictional resistance and has good biocompatibility, preventing the thrombus filtering device 1000 from rubbing against the arch wall 410 of the aortic arch 400, and facilitating the smooth and stable movement of the thrombus filtering device 1000 along the arch wall 410 of the aortic arch 400. It should be noted that, in the embodiments of this disclosure, coatings with other properties may also be selectively applied to the filter membrane 200, not limited to the antithrombotic coating and the coating with a low coefficient of friction described herein, and adjustments can be made according to actual conditions.
[0090] The following points need to be explained:
[0091] (1) The accompanying drawings of the embodiments of this disclosure only involve the structures involved in the embodiments of this disclosure. Other structures can be referred to the general design.
[0092] (2) Where there is no conflict, the embodiments of this disclosure and the features in the embodiments can be combined with each other to obtain new embodiments.
[0093] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. The scope of protection of this disclosure should be determined by the scope of protection of the claims.
Claims
1. A thrombus filtration device, characterized in that, include: The frame includes a first frame portion and a second frame portion, the first frame portion being configured to unfold to form a distal opening in an annular shape, and the second frame portion being configured to unfold to form a proximal opening in an annular shape. A filter membrane is disposed on and covers the frame such that the filter membrane can be supported by the frame to unfold into a tubular structure. A separator extends from the proximal opening toward the distal opening and is located within the tubular structure. The separator is configured to divide the inner cavity of the tubular structure near the proximal opening into a collection area and a channel area. The filter membrane corresponding to the collection area is stepped along the axial direction of the thrombus filtration device to form a stepped filter bag structure at the proximal opening. The stepped shape includes multiple serrations, which are arranged axially and circumferentially on the filter membrane in the collection area of the thrombus filtration device. The tubular structure is an arc-shaped tube, and the filter membrane includes a first part and a second part connected to each other. The first part is configured to unfold to form an arc-shaped back wall with a first curved surface, and the second part is configured to unfold to form an arc-shaped inner wall with a second curved surface, so that the arc-shaped tube has opposing arc-shaped back walls and arc-shaped inner walls. The plurality of serrations are located on the inner wall of the bow. The separator includes a curved isolation baffle, one side of which is connected to a portion of the proximal opening along its extension direction. The isolation baffle is connected to the two ends of the first curved surface and the second curved surface respectively, so that the inner cavity of the bow-shaped tube is divided into the collection area surrounded by the second curved surface and the separator and the channel area surrounded by the first curved surface and the separator.
2. The thrombus filtering device as described in claim 1, wherein, The isolation baffle includes a separation frame body and a multi-layer membrane structure covering the separation frame body, wherein the multi-layer membrane structure is a porous structure.
3. The thrombus filtering device as described in claim 1, wherein, The filter membrane corresponding to the collection area is configured as a multilayer membrane structure, and the multilayer membrane structure is a porous structure.
4. The thrombus filtering device as described in claim 2 or 3, wherein, The multilayer membrane structure is a double-layer membrane, which includes a first membrane and a second membrane. The first membrane is located on the side of the second membrane closer to the collection area, and the pore size of the first membrane is larger than that of the second membrane.
5. The thrombus filtering device as described in claim 4, wherein, A first interlayer gap exists between the first layer and the second layer, and the first interlayer gap is 2 mm-5 mm. The pore size of the first membrane layer ranges from 100 μm to 200 μm, and the pore size of the second membrane layer ranges from 50 μm to 70 μm.