Intracavity foreign matter catcher and intracavity foreign matter catching system

Abstract

The invention discloses an intracavitary foreign matter capturing device and an intracavitary foreign matter capturing system, and the intracavitary foreign matter capturing device comprises a filtering part which is of an expandable and contractible hollow net cylindrical structure, and an opening part is formed in the far end of the filtering part in the expanded state; the pushing catheter is connected to the near end of the filtering piece and can be axially and movably arranged in the guiding sheath tube in a penetrating manner; the far end of the traction piece is connected with the opening part and used for driving the opening part to close; and the shrinkage limiting piece is connected to the far end of the pushing catheter or arranged in the pushing catheter in a penetrating mode, the far end of the shrinkage limiting piece is provided with a shrinkage limiting section, and after the opening part is closed, the far end of the shrinkage limiting section is located in the filtering piece and abuts against the near end side of the closed opening part. According to the embodiment of the invention, by arranging the shrinkage limiting piece, excessive axial shrinkage when the filter piece is closed is avoided, and the recovery performance is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to an intracavitary foreign body catcher and an intracavitary foreign body capture system. Background Art

[0002] With the extensive clinical application and development of cardiovascular interventional surgeries worldwide. Cardiovascular interventional surgeries such as Transcatheter Aortic Valve Implantation (TAVI), transcatheter mitral valve replacement, percutaneous balloon mitral valvuloplasty, transcatheter "valve-in-valve" replacement, coronary artery intervention, left atrial appendage occlusion, transcatheter ablation, etc. During the surgery, foreign bodies such as calcified plaques, blood clots, oil droplets, implant fragments, etc. are likely to fall off and enter the cerebral blood vessels or other important organs along the blood flow direction, leading to serious complications such as stroke.

[0003] There is a disclosed femoral artery interventional cerebral protection device in the prior art, which is used to be positioned in the aorta during interventional surgeries such as transcatheter aortic valve implantation or transcatheter mitral valve replacement to intercept in advance these foreign bodies that are about to enter the cerebral arteries. The cerebral protection device in the prior art usually includes a filter with a distal opening. After the filter intercepts a foreign body, it needs to be retracted into the sheath. Due to various reasons, for example, during the process of pulling the distal opening of the filter by the wire to close the distal opening of the filter, since the filter is an elastic structure, the filter is prone to generate a large axial shortening under the pulling of the wire, so that the filter is a "short and fat" disc-shaped structure before recovery, thus making it difficult to retract the filter into the sheath, resulting in the problem of difficult filter recovery. Summary of the Invention

[0004] In order to overcome at least one of the above-mentioned defects in the prior art, the present invention provides an intracavitary foreign body catcher and an intracavitary foreign body capture system to reduce the problem of difficult recovery caused by excessive axial shortening of the filter element in the prior art.

[0005] The technical solution adopted by the present invention to solve its problems is as follows:

[0006] In a first aspect, the present invention provides an intracavitary foreign body catcher, including: a filter element, which is an expandable and contractible hollow cylindrical net structure. In the expanded state, an opening is formed at the distal end of the filter element; a push catheter, connected to the proximal end of the filter element and axially movably disposed within a guiding sheath; a traction member, whose distal end is connected to the opening for driving the opening to close; and a limiting member, connected to the distal end of the push catheter or disposed within the push catheter. The distal end of the limiting member has a limiting section. After the opening is closed, the distal end of the limiting section is located within the filter element and abuts against the proximal side of the closed opening.

[0007] In a second aspect, the present invention further provides an intracavitary foreign body capture system, comprising the above-mentioned intracavitary foreign body capturer and a guide sheath, wherein the push catheter of the intracavitary foreign body capturer can be axially movably disposed in the guide sheath.

[0008] The present invention provides an intracavity foreign body capture device and an intracavity foreign body capture system, which have the following technical effects:

[0009] By providing a shrinkage limiter and a shrinkage limiter section at the distal end of the shrinkage limiter, after the opening is closed, the distal end of the shrinkage limiter section abuts against the proximal side of the closed opening to ensure that the axial length of the filter element is not less than the axial length of the shrinkage limiter section along the filter element, so that the filter element will not be excessively shortened during the closing process, avoiding the problem of axial stacking of the filter element due to excessive shortening of the filter element, thereby improving the recovery performance of the intracavity foreign body trap. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic structural diagram of the intracavity foreign body trap in one embodiment of the present invention when the filter element is in a natural state;

[0011] Figure 2 It is a schematic diagram of an intracavitary foreign body capture device according to an embodiment of the present invention applied to the ascending aorta;

[0012] Figure 3 It is a structural schematic diagram of the intracavity foreign body trap in one embodiment of the present invention when the filter element is in a folded state;

[0013] Figure 4 It is a schematic diagram of the connection relationship between the limiting member and the pushing catheter in one embodiment of the present invention;

[0014] Figure 5 It is a schematic diagram of the connection relationship between the limiting member and the pushing catheter in another embodiment of the present invention;

[0015] Figure 6 for Figure 5 A schematic diagram of the structure of the shrinkage limiting member;

[0016] Figure 7 It is a structural schematic diagram of a traction member in one embodiment of the present invention;

[0017] Figure 8 It is a schematic diagram of a filter element of an intracavity foreign body trap in one embodiment of the present invention from one perspective;

[0018] Figure 9 It is a schematic diagram of a filter element of an intracavity foreign body trap in one embodiment of the present invention from another perspective;

[0019] Figure 10Schematic diagram of the filter element of the intracavitary foreign body catcher in another perspective in an embodiment of the present invention;

[0020] Figure 11 Schematic diagram of the elastic support of the filter element in an embodiment of the present invention from one perspective;

[0021] Figure 12 Schematic diagram of the elastic support of the filter element in an embodiment of the present invention from another perspective;

[0022] Figure 13 Schematic diagram of the elastic support of the filter element in another embodiment of the present invention from one perspective;

[0023] Figure 14 Schematic diagram of the connection relationship between the elastic support and the traction member of the filter element in an embodiment of the present invention;

[0024] Figure 15 Schematic diagram of the connection relationship between the elastic support and the traction member of the filter element in another embodiment of the present invention;

[0025] Figure 16 Schematic diagram of the connection relationship between the elastic support and the traction member of the filter element in another embodiment of the present invention;

[0026] Figure 17 Schematic diagram of the distal end of the filter element closing in an embodiment of the present invention;

[0027] Figure 18 Schematic diagram of the interception net of the filter element in an embodiment of the present invention from one perspective;

[0028] Figure 19 Schematic diagram of the interception net of the filter element in an embodiment of the present invention from another perspective;

[0029] Figure 20 Schematic diagram of the interception net of the filter element in another embodiment of the present invention from one perspective;

[0030] Figure 21 Schematic diagram of the overall structure of the intracavitary foreign body capture system in an embodiment of the present invention;

[0031] Figure 22a Schematic diagram of the operation step S2 of the intracavitary foreign body capture system in an embodiment of the present invention;

[0032] Figure 22b Schematic diagram of the operation step S3 of the intracavitary foreign body capture system in an embodiment of the present invention;

[0033] Figure 22c Schematic diagram of the operation step S4 of the intracavitary foreign body capture system in an embodiment of the present invention;

[0034] Figure 22d Schematic diagram of operation step S5 of the intracavitary foreign body capture system in an embodiment of the present invention.

[0035] Reference numerals:

[0036] 1000 - Intracavitary foreign body capture system;

[0037] 100 - Intracavitary foreign body capturer; 200 - Foreign body; 300 - Guiding sheath; 400 - Loading sheath;

[0038] 1 - Filter element; 2 - Pushing catheter; 3 - Closing assembly; 5 - Aorta; 7 - Handle;

[0039] 10 - Elastic stent; 20 - Intercepting net;

[0040] 11 - Opening part; 12 - Conical transition part; 13 - Connecting part; 31 - Traction member; 32 - Restricting member; 51 - Ascending aorta; 52 - Aortic arch part; 53 - Aortic valve; 61 - Brachiocephalic trunk artery; 62 - Left common carotid artery; 63 - Left subclavian artery; 5a - Convex side; 5b - Concave side;

[0041] 11a - Straight part; 11b - Gradually expanding part; 101 - First opening section; 102 - First conical transition section; 103 - Connecting section; 201 - Second conical transition section; 202 - Second opening section; 311 - Flexible section; 312 - Support section; 321 - Shaping section; 322 - Main body section; 32a - Distal section;

[0042] 1011 - First straight section, 1012 - First gradually expanding section; 2021 - Second straight section; 2022 - Second gradually expanding section;

[0043] a - Restricting section; b - Capture cavity; c - Flexible thread-like object; d - Thread-passing loop; e - Thread-passing loop group; f1 - First connecting member; f2 - Second connecting member; f3 - Third connecting member; g - Protrusion; j - Constraint structure; o - Sealing head, m1 - Thin wire; n1, n2 - Mesh holes. Detailed implementation manners

[0044] For better understanding and implementation, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of protection of the present application.

[0046] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention pertains. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0048] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", "connected to", "disposed on...", "fixed to", "disposed in" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements.

[0049] It should also be noted that in the field of interventional medical devices, the proximal end refers to the end closer to the operator, while the distal end refers to the end farther from the operator; the direction of the rotation central axis of an object such as a cylinder or a tube is defined as the axial direction; the circumferential direction is the direction around the axis of an object such as a cylinder or a tube (perpendicular to the axis and perpendicular to the cross-sectional radius at the same time); the radial direction refers to the direction along the diameter or radius. It should be noted that regardless of the "end" in the terms such as "proximal end", "distal end", "one end", "the other end", "the first end", "the second end", "the initial end", "the terminal end", "both ends", "the free end", "the upper end", "the lower end", etc., it is not limited to the end head, the end point or the end face, but also includes the part that extends a certain axial distance and / or radial distance on the element to which the end head, the end point or the end face belongs. The above definitions are only for the convenience of expression and should not be construed as a limitation on the present invention.

[0050] It should also be noted that phrases such as "an embodiment", "embodiments", "exemplary embodiments", "some embodiments", etc. mentioned in the specification indicate that the described embodiments may include specific features, structures, or characteristics, but not necessarily every embodiment includes such specific features, structures, or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. Moreover, when combining specific features, structures, or characteristics with an embodiment, it is within the knowledge scope of those skilled in the art to implement such features, structures, or characteristics in combination with other embodiments, whether explicitly or implicitly described.

[0051] Please refer to Figures 1-3 , an embodiment of the present invention provides an intracavitary foreign body capture device 100, which is used to intercept and recover foreign bodies 200 in a living body (such as a human body) during or before and after a surgical operation. Among them, the foreign bodies 200 can be calcified plaques, blood clots, oil droplets, etc., or can also be fragments, exfoliates, etc. of artificial valves (such as artificial mechanical valves), valve clips (such as mitral valve clips, tricuspid valve clips), or other implants, so as to prevent these foreign bodies 200 from entering the cerebral blood vessels or other important organs along the blood flow direction, resulting in serious complications such as stroke. The intracavitary foreign body capture device is particularly applicable to cardiovascular interventional surgeries, and is positioned in the target blood vessel on the downstream side of the lesion location in a cardiovascular interventional surgery, so as to capture the foreign bodies 200 that fall off or form during the surgical operation, thereby improving the safety and reliability of cardiovascular interventional surgeries. Among them, cardiovascular interventional surgeries include but are not limited to transcatheter aortic valve implantation, transcatheter aortic valve replacement, transcatheter mitral valve replacement, percutaneous mitral balloon valvuloplasty, transcatheter "valve-in-valve" replacement, coronary artery intervention, left atrial appendage occlusion, transcatheter ablation, etc.

[0052] As Figures 1-3 and Figure 8 shown, the intracavitary foreign body capture device 100 provided by the embodiment of the present invention includes:

[0053] The filter element 1 is a hollow net barrel-shaped structure that can be radially expanded and contracted. In the expanded state, an opening 11 is formed at the distal end of the filter element 1;

[0054] The push catheter 2 is connected to the proximal end of the filter element 1 and is axially movable through the guiding sheath 300 to drive the filter element 1 to extend out of the guiding sheath 300 or retract into the guiding sheath 300;

[0055] The traction member 31, whose distal end is connected to the opening 11, is used to generate an axial traction force towards the proximal direction to drive the opening 11 to close; and

[0056] The constriction member 32 is connected to the distal end of the push catheter 2 or is disposed inside the push catheter 2. At least when the opening portion 11 is fully closed, the constriction member 32 has a constricted section a received inside the filter member 1. After the opening portion 11 is fully closed, the distal end of the constricted section a is located inside the filter member 1 and abuts against the proximal side of the fully closed opening portion 11.

[0057] Understandably, in the embodiment of the present invention, by providing the constriction member 32, when the opening portion 11 is fully closed, the constriction member 32 has a constricted section a received inside the filter member 1. After the opening portion 11 is fully closed, the distal end of the constricted section a is located inside the filter member 1 and abuts against the proximal side of the fully closed opening portion 11, so as to ensure that the axial length of the filter member 1 is not less than the length of the constricted section a along the axis of the filter member 1, such that the filter member 1 will not be overly shortened during the closing process, avoiding the problem of axial stacking of the filter member 1 caused by excessive shortening of the filter member 1, thereby improving the recovery performance of the intracavitary foreign body catcher 100.

[0058] As Figure 2 shown, the filter member 1 is a component for capturing foreign bodies 200. The present invention mainly takes the filter member 1 being positioned at the ascending aorta 51 inside the aorta 5 as an example to illustrate the intracavitary foreign body capturing device 100 provided by the present invention. When the filter member 1 is positioned at the ascending aorta 51 inside the aorta 5, the opening portion 11 of the filter member 1 faces the aortic valve 53, and the filter member 1 is used to intercept and capture foreign bodies 200 that come from the heart and enter the aorta 5 along the X direction with the blood flow. Of course, the intracavitary foreign body capturing device 100 of the present invention can also be positioned at other positions in the human body (such as the aortic arch 52, the brachiocephalic trunk artery 61, the left common carotid artery 62, the left subclavian artery 63) to achieve the function of capturing foreign bodies 200, and the present invention does not make specific limitations thereto. It should be noted that in order to prevent foreign bodies 200 from entering the brain, when the filter member 1 is positioned at the aortic arch 52, the distal opening of the filter member 1 should be located on the upstream side (i.e., the side close to the ascending aorta 51) of the cerebral vascular branch (such as the brachiocephalic trunk artery 61, the left common carotid artery 62, the left subclavian artery 63) communicating with the aorta 5, so as to achieve the function of brain protection.

[0059] As Figures 1-3 shown, the filter member 1 is a hollow net barrel-shaped structure having elasticity and being elastically recoverable. The main shape of the filter member 1 is umbrella-shaped, funnel-shaped or trumpet-shaped, and it can undergo elastic deformation under an external acting force, such as being axially stretched, axially shortened, radially expanded and radially compressed under an external force. When the acting force disappears or changes, the filter member 1 returns to the pre-shaped state (i.e., the elastically recovered state, also the natural state). In the embodiment of the present invention, the filter member 1 includes but is not limited to the following states: natural state, working state, retracted state and recovery state. Among them, the natural state refers to the state without an external acting force (excluding its own gravity) (such asFigure 1 As shown, the working state refers to the state where the filter element 1 is self-expandingly positioned in the target blood vessel (such as the ascending aorta 51) and the distal end is in an open state (at this time, the inner wall of the blood vessel will give a certain degree of radial restraint force to the filter element 1, so that the filter element is supported in the blood vessel, as Figure 2 shown); when the filter element 1 is in the natural state and the working state, the filter element 1 is in a radially expanded form and has a capture cavity b extending along the axis of the filter element 1, and an opening 11 communicating with the capture cavity b is formed at its distal end. After the opening 11 is controlled to close by the traction member 31, the filter element 1 switches from the natural state / working state to the collapsed state (as Figure 3 and Figure 22c shown); then, the filter element 1 is further controlled to be retracted into the guiding sheath 300 (as Figure 22d shown), at this time, the filter element 1 changes from the collapsed state to the retracted state, and the filter element 1 is constrained to a radially contracted form in the guiding sheath 300, so as to facilitate the withdrawal of the filter element 1 from the human body.

[0060] The push catheter 2 is an elongated tubular member, which has an axially penetrating inner cavity, and the capture cavity b is connected to the inner cavity of the push catheter 2. During the operation, the push catheter 2 movably passes through the inner cavity of the guiding sheath 300 and is coaxially arranged, and the guiding sheath 300 provides a channel for the intracavitary foreign body capture device 100 to enter the target blood vessel. When the push catheter 2 moves axially distally along the inner cavity of the guiding sheath 300, it can drive the filter element 1 to extend from the distal end of the guiding sheath 300, so that the filter element 1 self-expandingly expands in the target blood vessel; when the push catheter 2 moves axially proximally along the inner cavity of the guiding sheath 300, it can drive the filter element 1 to be retracted into the guiding sheath 300, so that the filter element 1 changes to a radially contracted form. Among them, the inner cavity shapes of the push catheter 2 and the guiding sheath 300 are set as required and can be any shape as needed. Generally, the cross-section of each inner cavity of the push catheter 2 and the guiding sheath 300 is circular or elliptical to facilitate the smooth movement of the instrument in the inner cavity. The push catheter 2 and the guiding sheath 300 are single-layer or multi-layer composite tubular bodies. Preferably, the push catheter 2 and the guiding sheath 300 are made of an inner layer of PTFE (Polytetrafluoroethylene) inner membrane, a middle layer of metal braided reinforcement layer, and an outer layer of Pebax (Ployamide-ployether-block) material.

[0061] The intracavitary foreign body capturer 100 includes a closing assembly 3, and the closing assembly 3 is connected to the opening 11 of the filter element 1 for controlling the closing of the distal opening of the filter element 1, so that the capture cavity b of the filter element 1 forms a space for enclosing the foreign body 200.

[0062] The closing assembly 3 includes the above-mentioned traction member 31 and constriction member 32. Optionally, the constriction member 32 can be an elongated tubular member or an elongated rod-shaped member. The constriction member 32 is fixedly connected to the distal end of the push catheter 2 or is axially movably inserted into the push catheter 2 or axially fixedly inserted into the push catheter 2. When the constriction member 32 is inserted into the push catheter 2, the distal end of the constriction member 32 is always in a state of protruding from the distal end of the push catheter 2 or can protrude from the distal end of the push catheter 2 from within the push catheter 2.

[0063] Preferably, the constriction member 32 is arranged as a tubular structure. The constriction member 32 can be a single-lumen tube or a multi-lumen tube. The traction member 31 is inserted into the constriction member 32 and can protrude from the distal end of the push catheter 2 and be connected to the opening 11. It can be understood that by setting the constriction member 32 as a tube, the distal end of the constriction member 32 can provide a supporting force in the distal direction for the closing of the opening 11, which is beneficial to achieving rapid closing. At the same time, the traction member 31 being inserted into the constriction member 32 enables the opening 11 to move radially along the central axis of the constriction member 32 to close, so as to improve the tightness of the closing of the opening 11.

[0064] Combined Figure 1 、 Figure 4 and Figure 21 As shown in the figures, in some embodiments, the constriction member 32 is inserted into the push catheter 2, a distal portion of the constriction member 32 protrudes from the distal end of the push catheter 2, and a proximal end of the constriction member 32 protrudes from the proximal end of the push catheter 2 and is connected to a fixed portion (not shown in the figure) of the handle 7. When the handle 7 drives the traction member 31 to move axially in the proximal direction relative to the constriction member 32 and the push catheter 2, it drives the opening 11 to close.

[0065] In some other embodiments, the constriction member 32 is inserted into the push catheter 2, a proximal end of the constriction member 32 protrudes from the proximal end of the push catheter 2 and is connected to a movable portion (not shown in the figure) on the handle 7. The movable portion on the handle 7 can drive the constriction member 32 to move axially relative to the push catheter 2. Based on this, the movable portion on the handle 7 can drive the constriction member 32 to move axially in the distal direction relative to the traction member 31 and the push catheter 2 to control the opening 11 to close at the distal end of the constriction member 32.

[0066] Such as Figure 5As shown, in some other embodiments, the constricting member 32 can also be fixedly connected to the distal end of the pushing catheter 2. The handle 7 drives the traction member 31 to move axially in the proximal direction relative to the constricting member 32 and the pushing catheter 2 to drive the opening 11 to close. Specifically, the constricting member 32 can be integrally formed with the pushing catheter 2 or connected together by means such as sleeving, bonding, welding, etc. The inner diameter and outer diameter of the constricting member 32 can be the same as those of the pushing catheter 2, or can be smaller than the inner diameter and outer diameter of the pushing catheter 2. Preferably, the inner diameter of the constricting member 32 is equal to the inner diameter of the pushing catheter 2 to improve the mobility of the traction member 31 within the constricting member 32 and the pushing catheter 2 and avoid jamming when the traction member 31 moves axially. The outer diameter of the constricting member 32 is smaller than the outer diameter of the pushing catheter 2 to reduce the radial dimension after the filter element 1 contracts and improve the recovery performance of the filter element 1. In other embodiments, the inner diameter and outer diameter of the constricting member 32 can be the same as those of the pushing catheter 2, thereby simplifying the process flow and reducing the production cost.

[0067] As Figure 1 and Figure 3 shown, regardless of the manner in which the constricting member 32 is connected to the pushing catheter 2, preferably, when the opening 11 is completely closed, the length of the constricted section a in the axial direction of the filter element 1 is d1, and the axial length of the filter element 1 in the natural state is d2, d1≥(2 / 3)d2, where 50mm≤d2≤70mm. It can be understood that by setting d1≥2 / 3d2, the length of the constricting member 32 in the axial direction of the filter element 1 is ensured, and further, the situation where the filter element 1 is axially stacked and difficult to recover due to excessive axial compression of the filter element 1 during the closing process of the opening 11 of the filter element 1 is avoided.

[0068] As Figure 1 and Figure 5 shown, further, when the constricting member 32 is fixedly connected to the distal end of the pushing catheter 2, the axial length of the constricted section a remains unchanged. Preferably, the length of the part of the constricting member 32 located within the filter element 1 (that is, the part of the constricting member 32 located on the distal side of the pushing catheter 2) in the axial direction of the filter element 1 is d3, and the axial length of the filter element 1 in the natural state is d2, d3≤d2, where 50mm≤d2≤70mm. It can be understood that through the above settings, it is avoided that the constricting member 32 extends too far in the distal direction and obstructs the closing of the opening 11, and at the same time, it is avoided that the distal end of the constricting member 32 extends out of the distal end of the filter element 1 and abuts against the blood vessel wall or the aortic valve leaflet 53 (as Figure 2 shown) and causes tissue damage.

[0069] As Figure 5As shown, more preferably, when the constriction member 32 is fixedly connected to the distal end of the push catheter 2, in the natural state (i.e., when not subject to external forces (excluding its own gravity)), at least the distal portion of the constriction member 32 is bent or shaped to deviate from the central axis of the push catheter 2. Among them, the constriction member 32 can be a straight segment or an arc segment. In the natural state, the angle between the portion of the constriction member 32 that deviates from the central axis of the push catheter 2 and the central axis of the push catheter 2 is α1, where 30° ≤ α1 ≤ 90°, so as to adapt to the bending amplitude of the aortic arch 52 and the ascending aorta 51, and maintain the centering of the constriction member 32 within the filter element 1 in the working state, so that the constriction member 32 can be better retracted and retrieved. Combining Figure 2 and Figure 5 , it can be understood that when the filter element 1 is positioned in a curved blood vessel (such as the aortic arch 52), the push catheter 2 bends conforming to the blood vessel bend. At this time, the constriction member 32 has a stress in the direction of the aortic arch 52, causing the constriction member 32 to deflect towards the convex side 5a and resulting in the constriction member 32 being non-centered within the filter element 1 (the non-centering of the constriction member 32 within the filter element 1 easily causes uneven circumferential force on the filter element 1 during retrieval, making it difficult to retrieve. At the same time, the deviation of the constriction member 32 from the central position easily causes its distal end to damage the blood vessel wall or the aortic valve 53). In the present invention, by pre-setting the constriction member 32 to be bent or shaped to deviate from the central axis of the push catheter 2, when the filter element 1 is applied to a curved blood vessel (taking the aortic arch 52 as an example), the constriction member 32 deflects or bends towards the concave side 5b of the aortic arch 52 in the direction of deviating from the central axis of the push catheter 2, so as to offset the stress towards the convex side 5a generated by the bend, so that in the working state, the constriction member 32 is centered within the filter element 1 (referring to the central axes of the constriction member 32 and the filter element 1 being substantially coincident), enabling the opening 11 to be better retracted, and thus improving the retrievability of the filter element 1. Among them, the aortic arch 52 is the curved part of the aorta 5 in an arch shape. Three relatively large arteries branch out from the convex side 5a of the aortic arch 52, namely the brachiocephalic trunk artery 61, the left common carotid artery 62, and the left subclavian artery 63. The concave side 5b of the aortic arch 52 is the side opposite to the convex side 5a.

[0070] Such as Figure 5As shown, exemplarily, the distal segment 32a of the constriction member 32 is an arc segment, and the radius of curvature R1 of the distal segment 32a is 30 mm - 50 mm. The material of the constriction member 32 may be the same as that of the push catheter 2, or a material softer than the push catheter 2 may be selected. The present invention does not limit this. To improve the compliance of the constriction member 32 and avoid puncturing or scraping the tissue, the hardness of the constriction member 32 is preferably less than that of the push catheter 2. Exemplarily, the hardness of the constriction member 32 is 10D - 35D, and the hardness of the push catheter 2 is 55D - 72D. Among them, the difference in hardness can be achieved by setting different sizes and materials, and the present invention does not make specific limitations on this.

[0071] As Figure 1 , Figure 4 and Figure 6 shown, further, when the constriction member 32 is movably disposed through the distal end of the push catheter 2, the axial length of the constriction section a is adjustable. Preferably, the maximum length of the part of the constriction member 32 located within the filter member 1 along the axis of the filter member 1 is d4, and the axial length of the filter member 1 in the natural state is d2, and d4 ≤ (3 / 2)d2, where 50 mm ≤ d2 ≤ 70 mm. It can be understood that through the above settings, it is possible to avoid the constriction member 32 extending excessively in the distal direction and hindering the closing of the opening 11, and at the same time avoid the constriction member 32 damaging the inner wall of the blood vessel or the aortic valve 53.

[0072] Preferably, when the constriction member 32 is disposed through the push catheter 2 and the proximal end is connected to the handle 7, in the natural state (i.e., when not subjected to external forces (excluding its own gravity)), the constriction member 32 includes a main body section 322 and a shaping section 321 located at the distal end of the main body section 322. In the natural state, the shaping section 321 is bent or shaped in a direction deviating from the central axis of the main body section 322. Among them, the shaping section 321 can extend out of the distal end of the push catheter 2 and enter the capture cavity b of the filter member 1.

[0073] Among them, the shaping segment 321 can be a straight segment or an arc segment. In the natural state, the angle between the shaping segment 321 and the central axis of the distal end of the main segment 322 is α2, 30°≤α2≤90°, so as to adapt to the bending amplitude of the aortic arch 52 and the ascending aorta 51, and maintain the centering of the shaping segment 321 in the filter element 1 in the working state, so that the filter element 1 can be better retracted and recovered. It can be understood that when the filter element 1 is positioned in a curved blood vessel (such as the aortic arch 52), the push catheter 2 bends in accordance with the curvature of the blood vessel. At this time, the shaping segment 321 has a stress in the direction of the convex side 5a of the blood vessel, so that the shaping segment 321 deflects toward the convex side 5a, resulting in the shaping segment 321 being in a non-centered state in the filter element 1. The present invention pre-sets the distal section of the limiting component 32 (i.e., the shaping section 321) to bend or fold in a direction away from the central axis of the push catheter 2. When the filter element 1 is applied to a curved blood vessel (taking the aortic arch 52 as an example), the shaping section 321 deviates from the central axis of the push catheter 2 and deflects or folds toward the concave side 5b of the aortic arch 52 to offset the stress toward the convex side 5a caused by the bending, so that in the working state, the shaping section 321 is centered in the filter element 1 (the central axis of the limiting component 32 and the central axis of the filter element 1 substantially coincide with each other), thereby improving the retraction and recovery capabilities of the filter element 1.

[0074] Exemplarily, the shaping section 321 is set as an arc section, and the radius of curvature R2 of the shaping section 321 is 30mm-50mm. The material of the shaping section 321 and the main section 322 can be the same as the material of the push catheter 2, or a material softer than the push catheter 2 can be selected, and the present invention does not limit this. In order to improve the compliance of the limiting member 32 and avoid stabbing or scratching the blood vessel wall or the aortic valve 53, the hardness of the limiting member 32 is preferably less than that of the push catheter 2. Exemplarily, the hardness of the limiting member 32 is 10D-35D, and the hardness of the push catheter 2 is 55D-72D, wherein the difference in hardness can be achieved by setting different sizes and materials, and the present invention does not make specific limitations on this.

[0075] Please also read Figure 1 , Figure 3 , Figure 7 , Figures 14-17 Further, at least the distal end of the traction member 31 is divided into a flexible section 311 (that is, the traction member 31 can be the flexible section 311 as a whole, or only the distal end is divided into the flexible section 311), and the flexible section 311 includes at least one flexible thread c, and at least one flexible thread c is connected to the opening 11, and is used to control the closing of the opening 11 (such as Figure 17As shown. Correspondingly, a plurality of wire threading loops d are circumferentially arranged at the distal end of the opening 11, at least one flexible wire-like object c is connected to the plurality of wire threading loops d, and at least one flexible wire-like object c can control the plurality of wire threading loops d to approach each other, so that the opening 11 is closed. Wherein, the outer wall surface of the wire threading loop d has a smooth transition and no sharpness to reduce damage to the inner wall of the lumen tissue (such as blood vessels). It should be noted that in the embodiments of the present invention, the description of a plurality / root means two / root or more than two / root, and will not be described hereinafter.

[0076] Optionally, the number of the flexible wire-like objects c can be one or more. When the number of the flexible wire-like objects c is one, the distal end of the flexible wire-like object c sequentially passes through the plurality of wire threading loops d circumferentially to surround the opening 11 of the filter element 1 for approximately one week or more than one week (as Figure 14 shown). When the flexible wire-like object c is tightened in the proximal direction c, the plurality of wire threading loops d approach each other, so that the opening 11 is closed. When the number of the flexible wire-like objects c is two or more, the plurality of wire threading loops d are divided into a plurality of wire threading loop groups e in the circumferential direction (for example Figure 15 shows two wire threading loop groups e, Figure 16 shows 3 wire threading loop groups e). The number of the wire threading loop groups e is the same as and corresponds one-to-one to the number of the flexible wire-like objects c. The distal end of each flexible wire-like object c sequentially passes through the wire threading loops d of the corresponding wire threading loop group e circumferentially. When the plurality of flexible wire-like objects c are tightened in the proximal direction, the plurality of wire threading loops d of the plurality of wire threading loop groups e approach each other, so that the opening 11 is closed.

[0077] In some embodiments, when the flexible wire-like object c is at least two, the constricting member 32 can also be arranged as a multi-lumen tube, and each flexible wire-like object c movably passes through the corresponding independent lumen in the constricting member 32, so as to ensure that each flexible wire-like object c does not interfere with each other, reduce the frictional resistance between them, reduce the mutual winding, and ensure that the opening 11 of the filter element 1 opens and closes more smoothly.

[0078] Such as Figure 15 and Figure 16As shown, preferably, the number of the flexible filaments c is set to two or more. The plurality of wire threading rings d are circumferentially divided into a plurality of wire threading ring groups e. Each wire threading ring group e includes one or more wire threading rings d arranged in sequence in the circumferential direction. The number of the wire threading rings d in each wire threading ring group e may be the same or different. The plurality of flexible filaments c are dispersedly threaded through the corresponding wire threading ring groups e. It can be understood that by arranging the plurality of flexible filaments c to be respectively threaded through different wire threading ring groups e, compared with the method of arranging one flexible filament c to sequentially pass through a plurality of wire threading rings d in the circumferential direction, the opening 11 is made to remain as much as possible in the middle position, achieving centered closing, avoiding the problem that the opening 11 after closing deviates excessively from the central position, resulting in uneven circumferential force during the recovery of the filter element 1 and difficulty in recovery, and at the same time avoiding the distal end of the opening 11 deviating from the central position and damaging the blood vessel wall or the aortic valve leaflet 53. To further ensure the uniformity of the circumferential force on the opening 11 and achieve centered closing, the plurality of wire threading rings d are evenly arranged along the circumference of the opening 11 and the number of the wire threading rings d in the wire threading ring group e is the same or differs by within 2.

[0079] Preferably, the ratio of the number of the wire threading rings d to the number of the flexible filaments c is preferably between 1:1 and 5:1, more preferably between 3:1 and 4.5:1. It can be understood that when the number of the wire threading rings d is fixed, the smaller the ratio of the number of the wire threading rings d to the number of the flexible filaments c, the more the number of the flexible filaments c. When the number of the flexible filaments c is more, the possibility of winding and knotting between the flexible filaments c is greater, and the radial dimension occupied by all the flexible filaments c is larger, so that the required inner diameter of the push catheter 2 for loading the flexible filaments c is larger, which is not conducive to the delivery and recovery of the filter element 1. When the number of the flexible filaments c is too small, it will affect the centering of the closing of the opening 11 and the operation stroke of the flexible filaments c for closing is longer. Therefore, in the embodiment of the present invention, by setting the ratio of the number of the wire threading rings d to the number of the flexible filaments c to be preferably between 3:1 and 4.5:1, the required inner diameter of the push catheter 2 is reduced, the possibility of winding and knotting between the flexible filaments c is avoided as much as possible, and at the same time, the centering of the closing of the opening 11 is ensured and the movement stroke of the flexible filaments c for controlling the closing of the opening 11 is reduced.

[0080] As Figure 12As shown, preferably, each of the threading rings d has a corresponding first surface (not shown), and each of the first surfaces is a radial section of the filter element that is farthest from the corresponding threading ring d along the radial direction among the multiple radial sections of the filter element, and the annular surface of each threading ring d is perpendicular or approximately perpendicular to the corresponding first surface. In other words, the ring opening of each threading ring d is oriented or approximately oriented toward the ring opening of the adjacent threading ring d, so as to avoid the situation where the multiple threading rings d cannot be opened due to the interlacing and interspersing of the multiple threading rings d after the multiple threading rings d are gathered, so as to improve the reliability of the filter element 1, wherein approximately vertical has a phase difference range of 6° or less relative to vertical.

[0081] Preferably, the diameter of the loop of the threading ring d should be larger than the diameter of the flexible linear object c, so as to reduce the friction resistance between the threading ring d and the flexible linear object c and improve the smoothness of the opening 11 being retracted and elastically restored.

[0082] The threading ring d and the flexible thread c may be arranged in a variety of ways.

[0083] like Figure 12 and Figure 15 As shown, as an example, the number of threading rings d is 9, and the 9 threading rings d are evenly distributed at the distal end of the opening 11, and the number of flexible thread-like objects c is 2, wherein the 9 threading rings d are divided into two threading ring groups e, one of the two threading ring groups e includes 4 threading rings d arranged in sequence in the circumferential direction of the opening 11, and the other threading ring group e includes 5 threading rings d arranged in sequence in the circumferential direction of the opening 11; the two threading ring groups e correspond to the two flexible thread-like objects c one by one, the distal end of one flexible thread-like object c passes through the 4 threading rings d corresponding to one threading ring group e in sequence in the circumferential direction, and the distal end of the other flexible thread-like object c passes through the 5 threading rings d corresponding to the other threading ring group e in sequence in the circumferential direction.

[0084] It can be understood that the more threading rings d there are, the better the sealing effect of the opening 11, but the size requirement for the inner diameter of the push catheter 2 is higher. When the number of flexible thread objects c is two or more, the center of the opening 11 can be closed, but the more flexible thread objects c there are, the greater the possibility of entanglement and knotting between the flexible thread objects c. Based on the above, the embodiment of the present invention can achieve the center of the opening 11 to be closed by providing 9 threading rings d and two flexible thread objects c, while reducing the possibility of entanglement and knotting between the flexible thread objects c due to the excessive number of flexible thread objects c, and at the same time, reducing the size of the inner diameter of the push catheter 2 as much as possible, thereby increasing the recoverability of the filter element 1 and the passability of the push catheter 2 in the lumen. In other embodiments, such as Figure 16As shown, the nine wire threading loops d are divided into three groups of wire threading loops e. Correspondingly, the number of the flexible linear objects c is 3. In other embodiments, the number of the wire threading loops d can also be 18, 36, 72, etc., and the number of the flexible linear objects c can also be 1, 4, 5, etc. The present invention does not limit this. In other embodiments, the flexible linear object c can also be fixedly connected to the opening 11. The flexible linear object c realizes the closing of the opening 11 by pulling the opening 11 to move radially inwards.

[0085] The flexible linear object c can be a flexible linear object, such as a wire, a filament, a rope, a strip, a belt, etc. The radial cross-sectional shape of the flexible linear object c can be circular, oval, rectangular, square or other shapes, etc. The present application does not limit this. The flexible linear object c can be made of a biocompatible metal material and / or a polymer material, such as stainless steel 316L, tungsten, tantalum, nitinol alloy, polyethylene, polyamide, polypropylene, polyurethane, etc. Exemplarily, the flexible linear object c is a slender wire and can be woven by multiple metal filaments. Optionally, the flexible linear object c has radiopacity under a DSA (Digital Subtraction Angiography) device.

[0086] Please refer to again Figure 7 , further, the traction member 31 includes a flexible section 311 at the distal part and a support section 312 at the proximal end of the flexible section 311. In some embodiments, the proximal end of the support section 312 is connected to the handle 7. The support section 312 is made of a rigid material, and its hardness is greater than that of the flexible section 311. The support section 312 can be composed of a stainless steel tube or other harder materials. To ensure that the overall size of the instrument is small, generally, the outer diameter of the support section 312 can be set between 0.6 mm and 1 mm. The support section 312 can be a hollow tube structure or a solid rod structure. Since the whole instrument is placed in the ascending aorta 51 or the aortic arch 52 during use and is in a curved blood vessel or needs to pass through a section of curved blood vessel, the distal end of the traction member 31 is designed as the flexible section 311 to facilitate conforming to the curved blood vessel, and the proximal end of the traction member 31 is designed with a rigid material to ensure smooth pushing and withdrawing of the traction member 31. Exemplarily, the hardness of the flexible section 311 is 5D - 35D, and the hardness of the support section is 55D - 72D. To further improve the compliance of the support section 312 in the curved blood vessel, the support section 312 can also be a variable diameter structure with an outer diameter gradually decreasing from the proximal end to the distal end.

[0087] Further, when the filter element 1 is in a natural state, the overall shape of the filter element 1 is a funnel shape with a large distal end and a small proximal end. The cross-section of the filter element 1 is circular or oval. When the filter element 1 is applied to a blood vessel (such as the ascending aorta 51), the filter element 1 is in close fit with the inner wall of the blood vessel without a gap.

[0088] Please refer toFigure 2 , Figures 8-10 , the filter element 1 includes, in sequence from the distal end to the proximal end: an opening portion 11, a tapered transition portion 12, and a connecting portion 13. Among them, the opening portion 11 is located on the distal side to facilitate the entry of foreign matter 200 into the capture cavity b. The connecting portion 13 is used to realize the connection between the filter element 1 and the push catheter 2. The opening portion 11 of the filter element 1 has a relatively large opening, and the opening portion 11 has a certain length to facilitate attachment to the inner wall of the blood vessel. There are various structures of the opening portion 11. For example, it can be a cylindrical structure with the same diameter in the axial direction, or a frustum-shaped or arc-shaped structure with a larger distal end and a smaller proximal end. The distal end of the opening portion 11 abuts against the inner wall of the blood vessel to prevent gaps or angles from existing between the blood vessel wall, and can completely capture foreign matter 200 from the upstream side of the blood flow.

[0089] Preferably, the opening portion 11 includes a straight portion 11a with the same diameter in the axial direction and a gradually expanding portion 11b with an outer diameter gradually increasing along the axis from the proximal end to the distal end. The straight portion 11a is located between the tapered transition portion 12 and the gradually expanding portion 11b. Among them, the straight portion 11a is cylindrical and is used to cooperate with the inner wall of the blood vessel. Its outer diameter is the same as or slightly larger than the inner diameter of the blood vessel to maintain good wall attachment. The straight portion 11a has a certain length to better protect the inner wall of the blood vessel, and the cylindrical structure can better conform to the blood vessel to ensure smooth pushing to the predetermined position. The gradually expanding portion 11b can be a frustum-shaped or arc-shaped structure with a larger distal end and a smaller proximal end. When the filter element 1 is positioned in the blood vessel, the gradually expanding portion 11b expands radially outward and fits against the inner wall of the blood vessel under the constraint of the blood vessel (that is, in the working state, the gradually expanding section has a certain radial compression amount under the constraint of the blood vessel). Therefore, the maximum outer diameter of the gradually expanding portion 11b in the natural state should be greater than the inner diameter of the blood vessel. In order to ensure that the gradually expanding portion 11b has a certain radial compression amount under the constraint of the blood vessel, so that the gradually expanding portion 11b can abut against the blood vessel and fit well with the inner wall of the blood vessel, the maximum outer diameter of the gradually expanding portion 11b (that is, the outer diameter at the distal end) is greater than the inner diameter of the blood vessel and the outer diameter of the straight portion 11a. Exemplarily, the maximum outer diameter of the gradually expanding portion 11b is 10%-50% larger than the inner diameter of the blood vessel and the outer diameter of the straight portion 11a, so that the gradually expanding portion 11b has a certain radial compression amount in the inner wall of the blood vessel and the radial compression amount of the gradually expanding portion 11b is greater than that of the straight portion 11a to ensure good wall attachment of the gradually expanding portion 11b, avoid gaps between the gradually expanding portion 11b and the inner wall of the blood vessel, and at the same time ensure that the radial support force generated by the opening portion 11 on the inner wall of the blood vessel is within an appropriate range to avoid damaging the inner wall of the blood vessel. The tapered transition portion 12 is used to increase the area of blood flushing, so that the blood entering the filter main body 1 easily flows out from the tapered transition portion 12.

[0090] Exemplarily, the axial length of the straight portion 11a is between 30mm-40mm, the axial length of the expanding portion 11b is between 5mm-10mm, the axial length of the tapered transition portion 12 is between 25mm-40mm, and the axial length of the connecting portion 13 is between 2mm-5mm.

[0091] Exemplarily, when the filter element 1 is used in the ascending aorta 51, in a natural state, the outer diameter of the straight portion 11a is between 30mm and 50mm, and the maximum outer diameter of the gradually expanding portion 11b is between 40mm and 60mm. The gradually expanding portion 11b gradually expands and extends outward along the axial direction, and the angle β between the tangent line of each point at the distal end of the gradually expanding portion 11b and the central axis of the filter element 1 is between 45° and 80°. It can be understood that the larger the angle β, the greater the radial support force provided by the gradually expanding portion 11b. However, if the angle β exceeds 80°, it will affect the wall adhesion effect of the gradually expanding portion 11b after release. Therefore, the angle β is preferably between 45° and 60°.

[0092] In other embodiments, the straight portion 11a may also be replaced by a cylindrical-like structure with a wavy outer surface to increase the contact area with the inner wall of the blood vessel, improve wall adhesion, and increase the friction between them so that the filter element 1 can be better positioned in the blood vessel.

[0093] See also Figure 8 , Figure 9 , Figure 11 and Figure 18 Further, the filter element 1 includes an elastic support 10 and an interception net 20, the interception net 20 is fitted and fixed on the elastic support 10, the elastic support 10 is used to support the interception net 20, and the interception net 20 is used to intercept and filter the incoming foreign matter 200. It can be understood that the elastic support 10 is self-expanded and opens and fits the inner wall of the blood vessel to form a supporting support to ensure that the filter element 1 will not move with the flow of blood, and the interception net 20 is used to intercept the foreign matter 200 in the blood, thereby reducing the harm of the foreign matter 200 to the cerebral blood vessels and organ blood vessels.

[0094] The elastic support 10 includes, in sequence from the distal end to the proximal end: a first opening section 101, a first tapered transition section 102, and a connecting section 103. The interception net 20 includes, in sequence from the proximal end to the distal end: a second tapered transition section 201 and a second opening section 202. Among them, the second tapered transition section 201 is attached to the first tapered transition section 102. The first tapered transition section 102 is used to support the second tapered transition section 201. The shapes of the first tapered transition section 102 and the second tapered transition section 201 are adapted to each other. The first tapered transition section 102 and the second tapered transition section 201 constitute the tapered transition part 12 of the filter element 1. The second opening section 202 is attached to the first opening section 101. The first opening section 101 is used to support the second opening section 202. The shapes of the first opening section 101 and the second opening section 202 are adapted to each other. The first opening section 101 and the second opening section 202 constitute the opening part 11 of the filter element 1. The connecting section 103 of the elastic support 10 constitutes the connecting part 13 of the filter element 1.

[0095] More specifically, the first opening section 101 of the elastic support 10 includes a first straight section 1011 and a first gradually expanding section 1012. The second opening section 202 of the interception net 20 includes a second straight section 2021 and a second gradually expanding section 2022. The second straight section 2021 is attached to the first straight section 1011. The first straight section 1011 is used to support the second straight section 2021. The shapes of the first straight section 1011 and the second straight section 2021 are adapted to each other. The first straight section 1011 and the second straight section 2021 constitute the straight part 11a of the opening part 11. The second gradually expanding section 2022 is attached to the first gradually expanding section 1012. The first gradually expanding section 1012 is used to support the second gradually expanding section 2022. The shapes of the first gradually expanding section 1012 and the second gradually expanding section 2022 are adapted to each other. The first gradually expanding section 1012 and the second gradually expanding section 2022 constitute the gradually expanding part 11b of the opening part 11.

[0096] As Figure 11 shown, the elastic support 10 is an elastic and recoverable net-like structure. The elastic support 10 can undergo elastic deformation under the action of an external force. For example, it can be axially stretched, axially shortened, radially expanded, and radially compressed under the action of an external force. When the applied force disappears or changes, the elastic support 10 returns to its pre-shaped state. The shape of the interception net 20 is consistent with that of the elastic support 10. The interception net 20 can follow the elastic support 10 to undergo elastic deformation. When the elastic support 10 is in a natural state (i.e., without being subjected to an external force (excluding its own gravity)), the overall shape of the elastic support 10 is a funnel shape with a large distal end and a small proximal end.

[0097] Optionally, the elastic support 10 can be woven from a plurality of filaments m1, or can be cut and shaped from a metal steel pipe. The elastic support 10 provided by the present invention is woven from a plurality of filaments m1, and after the plurality of filaments m1 are woven and heat-shaped, an elastic support 10 having a radially contracted form and a radially expanded form is formed. The elastic support 10 is maintained in a radially contracted form in the guide sheath 300, and is in a radially expanded form after being released in vivo. It can be understood that the elastic support 10 woven from a plurality of filaments m1 has a simple structure and a simple process, and has better flexibility than a support formed by cutting, and the filaments m1 can be interlaced with each other to achieve the bending performance of the elastic support 10, wherein the filaments m1 can be made of a shape memory metal material, for example, nickel titanium wire can be used as the filaments m1.

[0098] Furthermore, the elastic support 10 has a proximal end and a distal end, the proximal end of the elastic support 10 is gathered and bound together by a head o to form a connecting portion 13 of the filter element 1, and the distal end of the elastic support 10 (i.e., the distal end of the first opening section 101) is formed with a plurality of circumferentially arranged protrusions g, and the plurality of protrusions g circumferentially surround the distal opening of the elastic support 10, the protrusions g are a closed hole-like structure and the plurality of protrusions g are evenly arranged along the circumferential direction, wherein all or part of the plurality of protrusions g are configured as a threading ring d for passing through the traction member 31.

[0099] Each protrusion g may be formed by a thin wire m1 being bent and wound around the distal end of the elastic support 10, and one thin wire m1 corresponds to one protrusion g. In other embodiments, each protrusion g may also be formed by the ends of two or more thin wires m1 being joined to the distal end of the elastic support 10, and in other embodiments, two or more thin wires m1 correspond to one protrusion g.

[0100] Optionally, all the protrusions g may be configured as threading rings d, or only part of the protrusions g may be configured as threading rings d (eg Figure 12 As shown), the ratio of the total number of protrusions g to the number of protrusions g set as threading loops d can be selected from 1, 2, and 3. When only part of the protrusions g are set as threading loops d, a plurality of protrusions g can be evenly arranged with a threading loop d every 1, 2, or 3 protrusions g in the circumferential direction. It can be understood that when the number of protrusions g set as threading loops d is greater, the sealing of the distal end of the elastic bracket 10 is better, but the opening 11 of the elastic bracket 10 is more difficult to close. In addition, in order to increase the structural stability of the threading loops d, a constraint structure j (constraint ring or constraint knot) can be set at each intersection of the threading loops d to constrain (such as Figure 12 shown).

[0101] like Figure 12 and Figure 15As shown, exemplarily, the elastic stent 10 is woven from 18 filaments m1. The 18 filaments m1 are bent and wound back at the distal end of the elastic stent 10 to form 18 protrusions g. Among them, for every other protrusion g in the circumferential direction among the 18 protrusions g, one is set as a threading loop d. That is, there are 9 threading loops d among the 18 protrusions g. The 9 threading loops d are divided into two threading loop groups e. One threading loop group e of the two threading loop groups e includes 4 threading loops d arranged in sequence in the circumferential direction of the opening 11, and the other threading loop group e includes 5 threading loops d arranged in sequence in the circumferential direction of the opening 11; the two threading loop groups e correspond one-to-one with 2 flexible linear objects c. The distal end of one flexible linear object c sequentially passes through 4 threading loops d corresponding to one threading loop group e, and the distal end of the other flexible linear object c sequentially passes through 5 threading loops d corresponding to the other threading loop group e. In other embodiments, as Figure 13 shown, it may also be that each protrusion g forms a threading loop d, that is, 18 protrusions g form 18 threading loops, and the present invention does not limit this.

[0102] Please refer to Figures 18-19 , further, the interception net 20 is used to fit on the inner surface and / or outer surface of the elastic stent 10. A plurality of mesh holes are provided on the interception net 20. The size of the mesh holes on the interception net 20 should allow blood cells to pass through while preventing foreign objects 200 from passing through. Therefore, the aperture of the mesh holes of the interception net 20 should be greater than 50um. Specifically, the size of the mesh holes can be set according to the size of the foreign objects to be intercepted actually. The aperture of the mesh holes is between 50um - 500um.

[0103] Exemplarily, the main foreign objects generated in the TAVI procedure are: thrombus, amorphous calcified particles, loose connective tissue; among them, the diameter range of the amorphous calcified particles is between 0.55mm - 1.8mm, and the diameter range of the loose connective tissue is 0.25mm - 4.0mm. If it is necessary to completely filter the calcified particles and the fallen loose connective tissue, the maximum aperture of the mesh holes of the interception net 20 shall not be greater than 250μm, so as to prevent the calcified particles and the loose connective tissue from participating in the human blood circulation and avoid the occurrence of embolism and other adverse symptoms. Therefore, the aperture of the mesh holes of the interception net 20 should be less than 250um.

[0104] The interception net 20 is formed by laser cutting or woven from silk threads arranged crosswise. For example, the interception net 20 woven from nitinol wire or other alloy wires with superelasticity and shape memory can also be the interception net 20 woven from nylon threads, or the interception net 20 woven from a combination of the above-mentioned nitinol wire and nylon threads, or the interception net 20 woven from materials such as PET (Polyethylene terephthalate), PE (Physical Education, polyethylene), and PTFE. Considering its visibility in the body, metal materials with visibility such as tantalum wire, platinum wire, and tungsten wire can be placed at intervals during weaving to improve its visibility effect in the body. The wire diameter of the above-mentioned silk threads should be between 0.1 mm and 0.25 mm. The interception net 20 can be a single-layer woven structure or a double-layer woven structure. Importantly, the interception net 20 allows blood cells to pass through and can effectively filter foreign objects 200.

[0105] The stretchable strength of the interception net 20 is between 10 N / mm and 20 N / mm, so that the interception net 20 can change its corresponding shape with the shape change of the elastic support 10 without causing a binding effect on the elastic support 10.

[0106] Please refer to Figure 9 , the distal peripheral edge of the interception net 20 is closely attached to the distal peripheral edge of the elastic support 10 to ensure that there is no separation or gap between the elastic support 10 and the interception net 20, and to avoid blood leakage. To ensure the close attachment of the distal peripheral edge of the interception net 20 to the distal peripheral edge of the elastic support 10, the distal end of the interception net 20 and the distal end of the elastic support 10 are fixed by a first connecting member f1. Among them, the first connecting member f1 includes at least one coil or at least one knot. The at least one coil or at least one knot is used to stitch, tie, or hook the distal end of the elastic support 10 and the distal end of the interception net 20 together circumferentially. Preferably, the first connecting member f1 includes at least one coil, and the at least one coil stitches around the distal end of the elastic support 10 and the distal end of the interception net 20 for at least one circle. To increase the stitching circumference and improve the connection stability, the first connecting member f1 can adopt a wavy or serrated wire routing method.

[0107] Please refer to Figure 10, Further, the first straight section 1011 of the elastic support 10 and the second straight section 2021 of the interception net 20 are fixed by a second connecting member f2. The second connecting member f2 includes at least one coil or at least one knot, and the at least one coil or at least one knot is used to stitch, tie or hook the first straight section 1011 of the elastic support 10 and the second straight section 2021 of the interception net 20 together in the circumferential direction. Preferably, the first connecting member f1 includes at least one coil, and the at least one coil stitches around the first straight section 1011 and the second straight section 2021 for at least one turn to achieve radial constraint between the first straight section 1011 and the second straight section 2021. In other embodiments, the second connecting member f2 may also include a plurality of knots (not shown in the figure). The plurality of knots are distributed in the circumferential direction, and each knot is used to tie a cross node on the first straight section 1011 and a cross node on the second straight section 2021 together to achieve the constraint between some cross nodes of the first straight section 1011 and some cross nodes of the second straight section 2021.

[0108] Please refer to Figure 20 , Further, the size of the mesh holes of the interception net 20 can vary in the circumferential direction. In some embodiments, the second tapered transition section 201 has smaller mesh holes than the second opening section 202. Among them, the second tapered transition section 201 is used to intercept foreign objects 200 in the blood. Therefore, there are higher requirements for the interception ability of the foreign objects 200. The second opening section 202 is used to fit the first opening section 101 of the elastic support 10, and the requirements for the interception ability of the foreign objects 200 are relatively low, but there are higher requirements for the deformation rate. It can be understood that if the mesh holes are too large, the blood permeability is too large and the foreign objects 200 cannot be effectively blocked; if the mesh holes are too small, it is easy to cause thrombus accumulation inside the mesh structure. In addition, the size of the mesh area of the mesh structure will also affect the deformation rate of the mesh structure. The larger the mesh area, the greater the deformation rate when subjected to external force; and the smaller the mesh area, the too small deformation rate when subjected to external force. Therefore, in the embodiments of the present invention, by setting the second tapered transition section 201 to have smaller mesh holes than the second opening section 202, the second tapered transition section 201 can effectively intercept the foreign objects 200, and at the same time the second opening section 202 can better follow the radial expansion or contraction of the elastic support 10.

[0109] Exemplarily, the aperture of the mesh hole n1 of the second tapered transition section 201 is between 0.06 mm and 0.15 mm, and the aperture of the mesh hole n2 of the second opening section 202 is between 0.15 mm and 0.25 mm.

[0110] Such as Figure 20As shown, optionally, the second tapered transition section 201 and the second opening section 202 can be integrally woven or spliced. When the second tapered transition section 201 has smaller mesh holes than the second opening section 202, preferably, the second tapered transition section 201 and the second opening section 202 are spliced together by a third connecting member f3. Since the denser the mesh holes, the greater the processing difficulty and the higher the cost, in the embodiments of the present invention, by means of splicing, the processing difficulty and cost of the interception net 20 are effectively reduced.

[0111] Optionally, the distal end of the second tapered transition section 201 and the proximal end of the second opening section 202 can be first spliced together by a third connecting member f3 and then attached to the elastic support 10, or they can be first attached to the corresponding positions on the elastic support 10 respectively and then spliced together by the third connecting member f3.

[0112] Among them, the third connecting member f3 includes at least one coil or knot, and at least one coil or knot is used to stitch, tie or hook the distal end of the second tapered transition section 201 and the proximal end of the second opening section 202 together along the circumferential direction. Preferably, the third connecting member f3 includes at least one coil, and at least one coil stitches around the distal end of the second tapered transition section 201 and the proximal end of the second opening section 202 for at least one circle.

[0113] Optionally, the first connecting member f1, the second connecting member f2 and the third connecting member f3 are flexible and can be made of biocompatible metal materials and / or polymer materials, such as stainless steel 316L, tungsten, tantalum, nitinol, polyethylene, polyamide, polypropylene, polyurethane, etc.

[0114] Please refer to Figure 21 , the embodiments of the present invention further provide an intracavitary foreign body capture system 1000, including the intracavitary foreign body capturer 100, the guiding sheath 300 and the handle 7 in any of the above embodiments. The handle 7 is connected to the proximal ends of the push catheter 2 and the closing assembly 3 and is used to control the actions of the push catheter 2 and the closing assembly 3. Among them, the filter element 1 and the push catheter 2 are movably inserted into the guiding sheath 300, and the guiding sheath 300 provides a channel for the intracavitary foreign body capturer 100 to enter the target cavity.

[0115] Furthermore, the intracavitary foreign body catcher 100 in the embodiments of the present invention further includes a loading sheath 400. The loading sheath 400 is pre-sleeved outside the pushing catheter 2. The loading sheath 400 is used to carry the filter element 1 and the distal end of the pushing catheter 2 into the guiding sheath 300. And the loading sheath 400 located between the pushing catheter 2 and the guiding sheath 300 can increase the sealing performance between the pushing catheter 2 and the guiding sheath 300. The pushing catheter 2 can slide axially relative to the loading sheath 400 and the guiding sheath 300. The loading sheath 400 can be a single-layer or multi-layer composite tube body. Preferably, the loading sheath 400 is made of an inner layer of PTFE inner membrane, a middle layer of metal braided reinforcement layer, and an outer layer of Pebax material, and has a hollow inner cavity. The loading sheath 400 is a commonly used sheath in the prior art, including the loading sheath 400 body and a sealing valve. The present application will not further describe the loading sheath 400.

[0116] Please refer to Figures 22a-22d , taking the intracavitary foreign body catcher 100 applied in the ascending aorta 51 as an example, the operation process of the intracavitary foreign body capture system 1000 of the present invention includes:

[0117] Step S1: Under the guidance of imaging devices such as ultrasound and / or Computed Tomography (CT) and / or DAS (Digital Subtraction Angiography), slowly push a guide wire (not shown in the figure) along the femoral artery to the ascending aorta 51 to establish a guiding path. Then, slowly push the guiding sheath 300 along the guide wire into the ascending aorta 51, and withdraw the guide wire.

[0118] Step S2: Please refer to Figure 22a , load the filter element 1 and the pushing catheter 2 into the loading sheath 400 (as Figure 21 shown), slowly insert the loading sheath 400 into the guiding sheath 300 through the proximal opening of the guiding sheath 300. At this time, the proximal end of the guiding sheath 300 is hermetically connected to the outer wall of the loading sheath 400. Then, push the pushing catheter 2 in the distal direction so that the filter element 1 extends out from the distal end of the loading sheath 400 and is constrained within the guiding sheath 300, keeping the distal end of the filter element 1 substantially flush with the distal end of the pushing catheter 2.

[0119] Step S3: Please refer to Figure 22b , slowly withdraw the guiding sheath 300 so that the filter element 1 is completely released from the inner cavity of the guiding sheath 300 and self-expands against the inner wall of the ascending aorta 51. At this time, the opening 11 of the filter element 1 is opened to intercept and capture the foreign body 200.

[0120] Step S4: Please refer to Figure 22c, after capturing the foreign object 200, the closing assembly 3 is driven by the handle 7 (as Figure 1 shown) to act, so that the opening 11 closes to prevent the foreign object 200 from flowing out in the reverse direction. It can be understood that in the present invention, by providing the constriction member 32, when the opening 11 is completely closed, the constriction member 32 has a constriction section a (as Figure 3 shown) received in the filter element 1. After the opening 11 is closed, the distal end of the constriction section a abuts against the proximal side of the closed opening 11 to ensure that the axial length of the filter element 1 is not less than the length of the constriction section a along the axis of the filter element 1, so that the filter element 1 will not be excessively shortened during the closing process, avoiding the problem of axial stacking of the filter element 1 caused by excessive shortening of the filter element 1, thereby improving the recovery performance of the intracavitary foreign object catcher 100.

[0121] Step S5: Please refer to Figure 22d , keep the guiding sheath 300 fixed, drive the filter element 1 to be sequentially recovered into the inner cavity of the guiding sheath 300 and the inner cavity of the loading sheath 400 through the handle 7, and then slowly withdraw the intracavitary foreign object catcher 100 and the guiding sheath 300 out of the body to end the operation.

[0122] The technical means disclosed in the solution of the present invention are not limited to the technical means disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. An intracavitary foreign body catcher, characterized in that, Comprising: A filter element, which is an expandable and contractible hollow net barrel-shaped structure. In the expanded state, an opening is formed at the distal end of the filter element; A pushing catheter, which is connected to the proximal end of the filter element and is axially movably disposed within a guiding sheath; A traction member, whose distal end is connected to the opening for driving the opening to close; and A restricting member, which is connected to the distal end of the pushing catheter or disposed within the pushing catheter. The distal end of the restricting member has a restricting section. After the opening closes, the distal end of the restricting section is located within the filter element and abuts against the proximal side of the closed opening.

2. The intracavitary foreign body catcher according to claim 1, wherein When the opening is completely closed, the length of the restricting section along the axis of the filter element is d1, and the axial length of the filter element in the natural state is d2, where d1 ≥ (2 / 3)d2.

3. The intracavitary foreign body catcher according to claim 1, wherein The restricting member is a tubular structure, and the traction member is movably disposed within the restricting member.

4. The intracavitary foreign body capturer according to any one of claims 1-3, characterized in that, The restricting member is fixedly connected to the distal end of the pushing catheter. By controlling the traction member to move in the proximal direction, the opening can be closed.

5. The intracavitary foreign body capturer according to claim 4, wherein The outer diameter of the restricting member is smaller than the outer diameter of the pushing catheter.

6. The intracavitary foreign body catcher according to claim 4, characterized in that, The length of the part of the restricting member located within the filter element along the axis of the filter element is d3, and the axial length of the filter element in the natural state is d2, where d3 ≤ d2.

7. The intracavitary foreign body capturer according to claim 4, characterized in that, In the natural state, at least the distal part of the restricting member is bent or folded in a direction deviating from the central axis of the pushing catheter.

8. The intracavitary foreign body capturer according to any one of claims 1-3, characterized in that, The restricting member is disposed through the distal end of the pushing catheter and can axially move relative to the pushing catheter. By controlling the traction member to move in the proximal direction and / or controlling the restricting member to push in the distal direction, the opening can be closed.

9. The intracavitary foreign body catcher according to claim 8, wherein, The maximum length of the part of the restricting member located within the filter element along the axis of the filter element is d4, and the axial length of the filter element in the natural state is d2, where d4 ≤ (3 / 2)d2.

10. The intracavitary foreign body catcher according to claim 8, wherein, The restricting member includes a main body section and a shaping section located at the distal end of the main body section. In the natural state, the shaping section is bent or folded in a direction deviating from the central axis of the main body section.

11. The intracavitary foreign body capturer according to any one of claims 1-3, characterized in that, The hardness of the restricting member is less than the hardness of the pushing catheter.

12. The intracavitary foreign body capturer according to any one of claims 1-3, characterized in that, The traction member includes at least one flexible thread-like object. A plurality of wire threading rings are circumferentially arranged at the distal end of the opening. The at least one flexible thread-like object can be movably disposed through each of the wire threading rings to control the plurality of wire threading rings to approach each other, so that the opening closes.

13. The intracavitary foreign body catcher according to claim 12, characterized in that, The traction member includes a support section and a flexible section located at the distal end of the support section. The support section has rigidity, and the flexible section includes the at least one flexible thread-like object.

14. The intracavitary foreign body catcher according to claim 12, wherein The number of the flexible thread-like objects is at least two. The plurality of wire threading rings are evenly arranged along the circumference of the opening. The plurality of wire threading rings are divided into wire threading ring groups with the same number as the number of the flexible thread-like objects. Each wire threading ring group includes one wire threading ring or at least two wire threading rings arranged in sequence along the circumference. The distal end of each flexible thread-like object respectively passes through the wire threading rings in the corresponding wire threading ring group along the circumference. The number of the wire threading rings in each wire threading ring group is the same or differs by no more than 2.

15. The intracavitary foreign body catcher according to claim 12, characterized in that, Each of the wire threading rings has a corresponding first surface, and each of the first surfaces is the radial cross-section that is the farthest from the corresponding wire threading ring along the radial distance among the multiple radial cross-sections of the filter element. The ring surface of each wire threading ring is perpendicular or substantially perpendicular to the corresponding first surface.

16. The intracavitary foreign body capturer according to any one of claims 1-3, wherein the filter element comprises an elastic bracket and an interception net, the interception net is attached to the inner surface and / or the outer surface of the elastic bracket, the elastic bracket is used for supporting the interception net, and the interception net is used for intercepting foreign bodies and allowing blood flow through.

17. The intracavitary foreign body capturer according to claim 16, wherein In the expanded state, the elastic bracket comprises a first tapered transition section and a first opening section located at the distal end of the first tapered transition section. The interception net comprises a second tapered transition section attached to the first tapered transition section and a second opening section attached to the first opening section. The second opening section has larger mesh holes than the second tapered transition section.

18. An intracavitary foreign body capture system, characterized in that, Comprising the intracavitary foreign body capturer according to any one of claims 1 to 17 and a guiding sheath, the push catheter of the intracavitary foreign body capturer is axially movably inserted into the guiding sheath.

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