Embolus retrieval stent

Abstract

The present invention belongs to the field of medical device technology, and in particular relates to a thrombus removal stent. The thrombus removal stent of the present invention comprises: a stent body and a retaining structure arranged inside the stent body, the stent body is arranged as a mesh structure, and the stent body can self-expand along its circumference; the retaining structure is formed by a retaining wire, and the retaining structure extends from the axial direction of the stent body. In the present invention, a retaining structure formed by a retaining wire is arranged inside the thrombus removal stent, which can fix the thrombus inside the thrombus removal stent, thereby effectively reducing the escape of the thrombus during the thrombus removal operation and improving the safety of the thrombus removal operation.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a thrombus removal stent. Background Art

[0002] Acute ischemic stroke (AIS) is a clinical syndrome characterized by impaired cerebral blood circulation due to various causes, resulting in ischemic hypoxic necrosis of brain tissue, including neurons, astrocytes, and oligodendrocytes, leading to neurological dysfunction. Acute ischemic stroke has a high morbidity, disability, and mortality rate, accounting for approximately 70% of all stroke cases.

[0003] In recent years, cerebrovascular disease has become the leading cause of death in my country and the main cause of disability in patients. It has become a public health issue in my country and even globally.

[0004] Current treatments for acute ischemic stroke primarily include thrombolysis and endovascular interventional therapy (such as endovascular mechanical thrombectomy). Intravenous thrombolysis primarily utilizes drugs such as recombinant tissue plasminogen activator (rt-PA) and urokinase (UK). The therapeutic window for thrombolysis is 3 to 6 hours. However, intravenous thrombolysis is less effective for acute large vessel occlusions. Literature reports suggest that the patency rate for terminal internal carotid artery occlusions is only 6%. Intravascular mechanical thrombectomy is the most significant advancement in the treatment of acute ischemic stroke in recent years, significantly extending the therapeutic window for AIS and significantly improving the prognosis of patients with ischemic stroke caused by acute large artery occlusion. Intravascular mechanical thrombectomy primarily uses digital subtraction angiography (DSA) to determine the location of the vascular occlusion. A thrombectomy device (such as a stent retriever) is then delivered to the occluded site using a nerve microguidewire and microcatheter, where the thrombus is removed externally, thereby rapidly re-opening the occluded vessel.

[0005] The thrombectomy stent in the existing technology is affected by factors such as structural design. During the thrombectomy process, the thrombus inside the thrombectomy stent is in a released state, which makes it easy for the thrombus to escape. The escaped thrombus will flow to the distal end of the blood vessel under the impact of blood flow to form a new embolism, thereby increasing the risk of surgery. Summary of the Invention

[0006] The present invention provides a thrombus removal stent, which is used to solve the technical problem that thrombi captured in the released thrombus removal stent are prone to escape during thrombus removal.

[0007] The thrombus removal stent of the present invention comprises: a stent body and a blocking structure arranged inside the stent body, wherein the stent body is configured as a mesh structure and the stent body can self-expand along its circumference;

[0008] The retaining structure is formed by a retaining wire and extends along the axial direction of the stent body.

[0009] In one embodiment, the arresting structure is formed by one or more arresting wires.

[0010] In one embodiment, the peripheral edge of the retaining structure is connected to the circumferential side wall of the bracket body.

[0011] In one embodiment, the axial projection of the arresting structure is symmetrically arranged along the radial direction of the bracket body.

[0012] In one embodiment, the barrier wire is made of a developing material;

[0013] Alternatively, the surface of the barrier wire is covered with a developing material.

[0014] In one embodiment, the stent body comprises a proximal region and a distal region connected in sequence.

[0015] The proximal region includes a plurality of first closed grids connected to each other, and the distal region includes a plurality of second closed grids connected to each other.

[0016] Wire holes are provided between adjacent second closed grids, and the wire holes are evenly distributed on the distal end region.

[0017] The blocking wire passes through the corresponding wire holes in sequence according to a preset trajectory to form the blocking structure inside the distal area.

[0018] In one embodiment, the threading hole is configured as a circular hole.

[0019] In one embodiment, the wire-threading holes are arranged between endpoints of adjacent second closed meshes.

[0020] In one embodiment, the proximal region is configured as a conical cylindrical structure.

[0021] In one embodiment, the first closed grid and the second closed grid are both configured as diamond shapes.

[0022] Compared with the prior art, the advantages of the present invention are: in the present invention, a blocking structure formed by a blocking wire is provided inside the thrombus removal stent, which can fix the thrombus inside the thrombus removal stent, thereby effectively reducing the escape of the thrombus during the thrombus removal operation and improving the safety of the thrombus removal operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Hereinafter, the present invention will be described in more detail based on embodiments with reference to the accompanying drawings.

[0024] Figure 1 is a schematic structural diagram of a thrombus removal stent in one embodiment of the present invention;

[0025] Figure 2 is a schematic structural diagram of a stent body in an expanded state according to an embodiment of the present invention;

[0026] Figure 3 Schematic diagram of the projection of the blocking structure of the first embodiment of the present invention on the axial section of the distal end of the stent body;

[0027] Figure 4 is a schematic diagram of the projection of the arresting structure of the second embodiment of the present invention on the axial section of the distal end of the stent body;

[0028] Figure 5 is a schematic diagram of a projection of an axial section of an arresting structure at the distal end of a stent body in one embodiment of the present invention;

[0029] Figure 6 FIG1 is a schematic diagram of a thrombus removal state of a thrombus removal stent according to an embodiment of the present invention.

[0030] Reference numerals:

[0031] 1. Stent body; 2. Arresting structure; 3. Thrombus;

[0032] 11. proximal region; 111. first closed grid;

[0033] 12. distal region; 121. second closed grid;

[0034] 13. Threading hole;

[0035] 21. Barrier wire. DETAILED DESCRIPTION

[0036] The present invention will be further described below with reference to the accompanying drawings. It should be understood that the terms "distal end" and "proximal end" in the present invention should be understood as being viewed from the direction of the operator, with the "distal end" being the side away from the operator and the "proximal end" being the side closer to the operator.

[0037] like Figure 1-6 As shown in the figure, the present invention provides a thrombus removal stent, comprising: a stent body 1 and a retaining structure 2 arranged inside the stent body 1, the stent body 1 is configured as a mesh structure, and the stent body 1 can self-expand along its circumferential direction; the retaining structure 2 is formed by a retaining wire 21, and the retaining structure 2 extends along the axial direction of the stent body 1.

[0038] In the present invention, a blocking structure 2 formed by a blocking wire 21 is set inside the thrombus removal stent, which can fix the thrombus 3 inside the thrombus removal stent, thereby effectively reducing the escape of the thrombus 3 during the thrombus removal operation and improving the safety of the thrombus 3 operation.

[0039] The retaining structure 2 is formed by one or more retaining wires 21 .

[0040] Preferably, one end of the arresting structure 2 is connected to the distal end of the stent body 1, and the other end is connected to the proximal end of the stent body 1. In other words, the arresting structure 2 extends from the distal end of the stent body 1 to the proximal end of the stent body 1, so that after the thrombus retriever is released, any thrombus 3 inside the stent can be captured and fixed by the arresting structure 2.

[0041] It should be noted that the proximal end of the thrombus removal stent is used to connect with the pushing rod.

[0042] In one embodiment, the peripheral edge of the retaining structure 2 is connected to the circumferential side wall of the bracket body 1 .

[0043] In this embodiment, the peripheral edge of the retaining structure 2 is connected to the circumferential side wall of the stent body 1, so that it can naturally open as the thrombus removal stent expands after entering the blood vessel, filling the interior of the stent body 1 to fuse with the thrombus 3 captured inside the stent body 1 and prevent the thrombus 3 from escaping.

[0044] Further preferably, the axial projection of the arresting structure 2 is symmetrically arranged along the radial direction of the stent body 1. The arresting structure 2 is evenly arranged in the internal space of the stent body 1 to evenly and fully fuse with the thrombus 3 inside the stent body 1.

[0045] The blocking wire 21 can construct different blocking structures 2 in the bracket body 1 according to different preset trajectories. Figure 3 As shown in , the projection of the blocking structure 2 on the axial section of the distal end of the stent body 1 is three parallel line segments, one of which is located on the diameter of the stent body 1, and the other two line segments are symmetrically arranged on both sides of the line segment located on the diameter of the stent body 1. Figure 4 As shown in FIG, the projection of the blocking structure 2 on the axial section of the distal end of the stent body 1 is two cross-shaped line segments. Figure 5 As shown in FIG, the blocking structure 2 on the axial end face of the distal end of the stent body 1 is composed of two line segment groups symmetrically arranged along the diameter of the stent body 1, and each line segment group includes two line segments that intersect with each other.

[0046] Preferably, the retaining wire 21 is made of a developing material; alternatively, the surface of the retaining wire 21 is covered with a developing material. In other words, the retaining wire 21 has a developing property. After the thrombectomy stent is released into a blood vessel during an interventional procedure, the position of the stent can be located through the retaining structure 2, and the deployment state of the retaining structure 2 and the stent body 1 can be observed.

[0047] Specifically, the barrier wire 21 is made of platinum-tungsten alloy or platinum-iridium alloy, preferably platinum-iridium alloy.

[0048] In one embodiment, the stent body 1 includes a proximal region 11 and a distal region 12 connected in sequence, the proximal region 11 includes a plurality of first closed grids 111 connected to each other, and the distal region 12 includes a plurality of second closed grids 121 connected to each other, and wire holes 13 are arranged between adjacent second closed grids 121, and the wire holes 13 are evenly distributed on the distal region 12, wherein the blocking wire 21 passes through the corresponding wire holes 13 in sequence according to a preset trajectory to form a blocking structure 2 inside the distal region 12.

[0049] In other words, in this embodiment, the wire threading hole 13 is provided in the distal region 12 of the stent body 1 so that the retaining structure 2 is constructed inside the stent body 1 through the retaining wire 21 .

[0050] The threading holes 13 are evenly distributed in the distal region 12. Figure 2 As shown in FIG, the distal region 12 is provided with multiple rows of axially spaced wire holes 13, with each row of wire holes 13 equally spaced between the axial ends of the distal region 12. This allows the operator to design the threading path of the arresting wire 21 in a variety of ways, select the appropriate wire holes 13 to thread the arresting wire 21, and construct different arresting structures 2 within the distal region 12.

[0051] Specifically, the threading hole 13 is configured as a circular hole.

[0052] Preferably, the threading holes 13 are provided between the endpoints of adjacent second closed grids 121 .

[0053] Specifically, the proximal region 11 is configured as a conical cylindrical structure to facilitate the withdrawal of the thrombus retriever stent.

[0054] In addition, the distal region 12 is configured as a cylindrical structure, wherein the thrombus 3 is captured and fixed mainly through the distal region 12 in the thrombus removal stent.

[0055] like Figure 2 As shown in FIG, after the stent body 1 is unfolded, its proximal end region 11 is triangular and its distal end region 12 is rectangular.

[0056] Specifically, the first closed grid 111 and the second closed grid 121 are both arranged in a rhombus shape.

[0057] like Figure 6 As shown in the figure, the thrombectomy stent is released after entering the blood vessel through interventional surgery. After the release, the proximal region 11 and the distal region 12 of the thrombectomy stent both expand outward and adhere closely to the inner wall of the blood vessel. The retaining structure 2 formed by the retaining wire 21 in the stent body 1 naturally opens as the thrombectomy stent expands and opens, and its open state can be seen under perspective. The retaining structure 2 is embedded in the thrombus 3 and fixes the thrombus 3 inside the thrombectomy stent. During the process of withdrawing the thrombectomy stent, the retaining structure 2 can effectively reduce the escape of the thrombus 3 during the thrombectomy operation.

[0058] The following specifically describes how the retaining structure 2 is constructed inside the bracket body 1 by using the retaining wire 21.

[0059] The unfolded state of the stent body 1 is as follows Figure 2 As shown in the figure, the distal region 12 of the stent body 1 is sequentially provided with seven rows of wire threading holes 13, which are the first row, the second row, the third row, the fourth row, the fifth row, the sixth row, and the seventh row from top to bottom in the direction shown in the figure, wherein the odd-numbered rows each include four wire threading holes 13, which are the first hole, the second hole, the third hole, and the fourth hole from the distal end to the proximal end; the even-numbered rows each include five wire threading holes 13, which are the first hole, the second hole, the third hole, the fourth hole, and the fifth hole from the distal end to the proximal end. The distal endpoints of the stent body 1 are the first distal endpoint, the second distal endpoint, the third distal endpoint, and the fourth distal endpoint from top to bottom in the direction shown in the figure. The proximal region 11 of the stent body 1 is triangular when unfolded, that is, the proximal ends of the stent body 1 converge into a point.

[0060] Example 1

[0061] In this embodiment, three barrier wires 21 are used to construct the barrier structure 2 , and the three barrier wires 21 are respectively a first barrier wire 21 , a second barrier wire 21 and a third barrier wire 21 .

[0062] The first blocking wire 21 is spirally reciprocatingly wound between the first row of wire holes 13 and the fifth row of wire holes 13. The first end of the first blocking wire 21 is pre-fixed (welded) on the first distal end point, and then the second end of the first blocking wire 21 is wound along the second closed grid 121 of the distal area 12. First, the second end of the first blocking wire 21 passes through the first hole of the first row, extends downward and passes through the first hole of the fifth row, and then returns in sequence to pass through the second hole of the first row, the second hole of the fifth row, the third hole of the first row, the third hole of the fifth row, the fourth hole of the first row, and the fourth hole of the fifth row. Finally, the second end of the first blocking wire 21 is gathered to the proximal end point of the bracket body 1 and fixed (welded).

[0063] The second blocking wire 21 is spirally wound back and forth between the second row of wire holes 13 and the sixth row of wire holes 13, and the first end of the second blocking wire 21 is pre-fixed (welded) on the second distal end point, and then the second end of the second blocking wire 21 is wound along the second closed grid 121 of the distal area 12. First, the second end of the second blocking wire 21 passes through the first hole of the second row, extends downward and passes through the first hole of the sixth row, and then returns in sequence to pass through the second hole of the second row, the second hole of the sixth row, the third hole of the second row, the third hole of the sixth row, the fourth hole of the second row, and the fourth hole of the sixth row, and finally the second end of the second blocking wire 21 is gathered to the proximal end point of the bracket body 1 and (welded) fixed.

[0064] The third blocking wire 21 is spirally wound back and forth between the third row of wire holes 13 and the seventh row of wire holes 13, and the first end of the third blocking wire 21 is pre-fixed (welded) on the second distal end point, and then the second end of the third blocking wire 21 is wound along the second closed grid 121 of the distal area 12. First, the second end of the third blocking wire 21 passes through the first hole of the third row, extends downward and passes through the first hole of the seventh row, and then returns in sequence to pass through the second hole of the third row, the second hole of the seventh row, the third hole of the third row, the third hole of the seventh row, the fourth hole of the third row, and the fourth hole of the seventh row, and finally the second end of the third blocking wire 21 is gathered to the proximal end point of the bracket body 1 and (welded) fixed.

[0065] Finally, the first barrier wire 21, the second barrier wire 21 and the third barrier wire 21 form Figure 3 The arresting structure 2 shown in FIG. Figure 3 As shown in the figure, the projection of the blocking structure 2 on the axial section of the distal end of the stent body 1 is three parallel line segments, one of which is located on the diameter of the stent body 1, and the other two line segments are symmetrically arranged on both sides of the line segment located on the diameter of the stent body 1.

[0066] Example 2

[0067] In this embodiment, two barrier wires 21 are used to construct the barrier structure 2, and the two barrier wires 21 are respectively a first barrier wire 21 and a second barrier wire 21.

[0068] The first blocking wire 21 is threaded back and forth between the first row of threading holes 13 and the fifth row of threading holes 13. The first end of the first blocking wire 21 is pre-fixed (welded) on the first distal end point, and then the second end of the first blocking wire 21 is wrapped around the second closed grid 121 of the distal area 12. First, the second end of the first blocking wire 21 passes through the first hole of the first row, extends downward and passes through the first hole of the fifth row, and then returns in sequence to pass through the second hole of the first row, the second hole of the fifth row, the third hole of the first row, the third hole of the fourth row, the fourth hole of the first row, and the fourth hole of the fourth row, and finally the second end of the first blocking wire 21 is converged to the proximal end point of the stent body 1.

[0069] The second blocking wire 21 is threaded back and forth in a spiral manner between the third row of threading holes 13 and the seventh row of threading holes 13, and the first end of the second blocking wire 21 is pre-fixed (welded) on the second distal end point, and then the second end of the second blocking wire 21 is wrapped around the second closed grid 121 of the distal area 12. First, the second end of the second blocking wire 21 passes through the first hole of the third row, extends downward and passes through the first hole of the seventh row, and then passes through the second hole of the third row, the second hole of the seventh row, the third hole of the third row, the third hole of the seventh row, the fourth hole of the third row, and the fourth hole of the seventh row in sequence, and finally the second end of the second blocking wire 21 is gathered to the proximal end point of the bracket body 1 and fixed (welded).

[0070] Finally, the first barrier wire 21, the second barrier wire 21 and the third barrier wire 21 form Figure 4 The blocking structure 2 shown in FIG. When the stent body 1 is in the released state, the angle between the line connecting the first row of wire holes 13 and the third row of wire holes 13 and the center of the axial cross section of the stent body 1 is 90°. Similarly, the angle between the line connecting the fifth row of wire holes 13 and the seventh row of wire holes 13 and the center of the axial cross section of the stent body 1 is 90°. Figure 4 As shown in FIG, the projection of the blocking structure 2 on the axial section of the distal end of the support body 1 is two line segments intersecting in a "cross" shape.

[0071] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0072] In the description of the present invention, it should be understood that the terms "upper," "lower," and the like indicate orientations or positional relationships based on those shown in the accompanying drawings. These terms are used solely to facilitate the description of the present invention and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and so on are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features designated as "first," "second," and so on may explicitly or implicitly include one or more of such features.

[0073] While the present invention has been described with reference to preferred embodiments, various modifications may be made and equivalent components may be substituted without departing from the scope of the present invention. In particular, the various technical features described in the various embodiments may be combined in any manner, provided no structural conflicts exist. The present invention is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A thrombus removal stent, characterized in that: include: The bracket body and the blocking structure arranged inside the bracket body, The stent body is configured as a mesh structure, and the stent body is capable of self-expanding along its circumference; The arresting structure is formed by an arresting wire, and the arresting structure extends along the axial direction of the stent body; The stent body includes a proximal region and a distal region connected in sequence, the proximal region includes a plurality of first closed grids connected to each other, the distal region includes a plurality of second closed grids connected to each other, wire holes are provided between adjacent second closed grids, the wire holes are evenly distributed on the distal region, wherein the blocking wire passes through the corresponding wire holes in sequence according to a preset trajectory to form the blocking structure inside the distal region; The outer peripheral edge of the retaining structure is connected to the circumferential side wall of the bracket body, and the axial projection of the retaining structure is symmetrically arranged along the radial direction of the bracket body.

2. The thrombus removal stent according to claim 1, characterized in that: The arresting structure is formed by one or more arresting wires.

3. The thrombus removal stent according to claim 1 or 2, characterized in that: The barrier wire is made of a developing material; Alternatively, the surface of the barrier wire is covered with a developing material.

4. The thrombus removal stent according to claim 1, characterized in that: The threading hole is configured as a circular hole.

5. The thrombus removal stent according to claim 1, characterized in that: The threading holes are arranged between the endpoints of adjacent second closed grids.

6. The thrombus removal stent according to claim 1, characterized in that: The proximal region is configured as a conical cylindrical structure.

7. The thrombus removal stent according to claim 1, characterized in that: The first closed grid and the second closed grid are both configured as diamond shapes.

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