Thrombectomy device

Abstract

The thrombectomy device comprises a thrombectomy support, a driving wire and a supporting structure, an inner cavity is formed in the thrombectomy support, the thrombectomy support comprises a cutting part located at the near end, an opening communicated with the inner cavity is formed in the cutting part, the cutting part comprises a far-end end and a near-end end, and the far-end end and the near-end end are communicated with each other through the opening. The near-end end part is of a tip structure pointing to the near end; the far end of the driving wire is connected with the thrombectomy stent, and the connecting part of the driving wire and the thrombectomy stent is located at the far end of the far end part or the axial distance between the connecting part and the far end part is zero; one end of the supporting structure is connected with the connecting part, and the other end of the supporting structure is connected with the near-end end part. The thrombus extraction efficiency of the thrombus extraction device is high.

Description

Technical Field

[0001] This invention relates to the technical field of medical devices, and more particularly to a thrombectomy device. Background Technology

[0002] This section provides only background information relevant to this disclosure and is not necessarily prior art.

[0003] Deep vein thrombosis (DVT) is a venous disease caused by abnormal clotting of blood in the deep veins of the lower limbs. It can cause venous occlusion, preventing blood from returning to the heart normally and causing various symptoms such as lower limb pain and swelling. When the embolus breaks off and flows into the lungs with the blood circulation, it can cause pulmonary embolism (PE), which can lead to death in severe cases.

[0004] Currently, the main treatment for deep vein thrombosis (DVT) includes mechanical thrombectomy. Mechanical thrombectomy involves inserting a thrombectomy stent into the blood vessel and placing it distal to the thrombus. The stent then expands within the vessel and adheres to the vessel wall. It is then moved proximally relative to the vessel. During this proximal axial movement, the stent intercepts free thrombi in the vessel and scrapes thrombi from the vessel wall, collecting them within the stent. Finally, the stent is withdrawn from the body, removing the thrombus and thus clearing the blockage and restoring blood flow. Mechanical thrombectomy avoids or reduces the need for anticoagulants and results in less blood loss.

[0005] An ideal thrombectomy device should possess at least the following characteristics: a sufficiently large single-shot thrombectomy capacity to achieve high thrombectomy efficiency. One feasible method to improve single-shot thrombectomy capacity is to design a thrombectomy stent with a proximal opening, and to design the stent opening to be as large as possible so that, during a single thrombectomy, as much thrombus attached to the vessel wall as possible can be scraped away, and the scraped thrombus is intercepted within the stent. To achieve a larger opening, a drive rod is typically connected to one end of the stent opening. During thrombectomy, the drive rod is pulled to move the stent along the vessel wall to scrape away the thrombus. Since the drive rod is connected to one end of the stent opening, the stent opening will inevitably encounter resistance from the thrombus during thrombectomy. Therefore, sufficient tensile force must be applied by the drive rod to allow the stent to move. Consequently, the drive rod inevitably pulls the stent axially, causing the stent opening to be subjected to axial tension and radial contraction. When the stent opening contracts radially, it becomes difficult to completely scrape away the thrombus attached to the vessel wall, thus reducing thrombectomy efficiency. Summary of the Invention

[0006] Therefore, it is necessary to provide a thrombectomy device with high thrombectomy efficiency.

[0007] A thrombectomy device, comprising:

[0008] A thrombectomy stent, the thrombectomy stent having an inner cavity, the thrombectomy stent including a cutting portion located at the proximal end, the cutting portion having an opening communicating with the inner cavity, the cutting portion including a distal end and a proximal end, the proximal end being a pointed tip structure pointing proximally;

[0009] A drive wire, the distal end of which is connected to the thrombectomy bracket, and the connection point between the drive wire and the thrombectomy bracket is located at the distal end of the distal end or the axial distance between the connection point and the distal end is zero.

[0010] A support structure, one end of which is connected to the connecting portion and the other end of which is connected to the proximal end.

[0011] The aforementioned thrombectomy device includes a thrombectomy stent, a drive wire, and a support structure. The drive wire pulls the thrombectomy stent to move it and scrape away the thrombus. Since the connection point between the drive wire and the thrombectomy stent is located at the distal end of the cutting section, or the axial distance between the drive wire and the distal end is zero, the drive wire does not directly exert axial tension on the opening of the cutting section, thus mitigating radial contraction of the opening. Furthermore, because the proximal end of the cutting section is a pointed structure pointing proximally, the resistance from the thrombus at the proximal end is relatively small. Simultaneously, one end of the support structure is connected to the connection point, and the other end is connected to the proximal end. During thrombectomy, the support structure supports the pointed structure, helping to prevent deformation of the proximal end and thus preventing effective thrombus scraping when the pointed structure passes through the thrombus.

[0012] Therefore, this thrombectomy device has a high thrombectomy efficiency. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] in:

[0015] Figure 1 This is a schematic diagram of the thrombectomy device in one embodiment, wherein the support structure of the thrombectomy device is not shown in the figure;

[0016] Figure 2 This is a perspective view of the device in one embodiment. Figure 2 To better illustrate the outline of the thrombectomy stent, the grid structure of the thrombectomy stent is not shown in the figure.

[0017] Figure 3 This is a schematic diagram of the mesh structure in one embodiment;

[0018] Figure 4 for Figure 3 A diagram showing the state of a mesh structure when it is stretched axially.

[0019] Figure 5A This is a schematic diagram of the support structure and the mesh structure used to connect the proximal end and the connection part in one embodiment;

[0020] Figure 5B for Figure 5A A schematic diagram of the supporting structure in the middle;

[0021] Figure 6 This is a schematic diagram of the support structure and the mesh structure used to connect the proximal end and the connection part in another embodiment;

[0022] Figure 7 This is a schematic diagram of the support structure and the mesh structure used to connect the proximal end and the connection part in another embodiment. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] In the description of the embodiments of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a replaceable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0026] In the field of interventional medical devices, the end of a medical device implanted in the human or animal body that is closer to the operator is generally called the "proximal end," and the end that is farther from the operator is called the "distal end." Based on this principle, the "proximal end" and "distal end" of any component of a medical device are defined. "Axial direction" generally refers to the length of the medical device during delivery, while "radial direction" generally refers to the direction of the medical device that is not parallel to its "axial direction." Based on this principle, the "axial direction" and "radial direction" of any component of a medical device are defined. "Circumferential direction" refers to the circumferential direction, that is, the axial direction surrounding a tubular structure or cylinder.

[0027] Please see Figure 1 and Figure 2 This disclosure provides a thrombectomy device 100, including a thrombectomy bracket 10 and a drive wire 20, wherein the drive wire 20 is connected to the thrombectomy bracket 10.

[0028] Please refer to the following: Figure 1 and Figure 3 The thrombectomy support 10 includes multiple grid structures 11. Each grid structure 11 is polygonal and includes multiple interconnected poles 111. The thrombectomy support 10 can be formed by braiding and shaping braided wire, or by cutting and shaping hollow tubing. The braided wire can be nickel-titanium alloy wire, stainless steel wire, or other metal wire. The hollow tubing can be nickel-titanium alloy tubing, stainless steel tubing, or other metal tubing, or it can be a polymer tubing.

[0029] The stent 10 is radially compressible, compressible to a loading size under restraint forces (radial compressive force on the stent 10 or axial tensile force applied to both ends of the stent 10) to facilitate loading of the stent 10 into the delivery catheter 50 (described below) for delivery into the patient's blood vessel. Please refer to [further details omitted]. Figure 3 and Figure 4 When the thrombectomy bracket 10 is subjected to a binding force, the mesh rods 111 of each mesh structure 11 move closer to each other in the circumferential direction, and the axial length of each mesh structure 11 increases, thereby increasing the axial length of the thrombectomy bracket 10 and decreasing its radial dimension.

[0030] The thrombectomy stent 10 is self-expanding, meaning that when the restraining force on the thrombectomy stent 10 is removed, the thrombectomy stent 10 can expand and be radially deployed. For example, after the delivery catheter 50 fitted on the thrombectomy stent 10 is withdrawn and separated from the thrombectomy stent 10, the thrombectomy stent 10 can radially expand and be radially deployed.

[0031] Please see Figure 1 and Figure 2 The thrombectomy stent 10 has an inner lumen 12 and includes a proximal cutting portion 13, which is a circumferentially closed ring structure. The cutting portion 13 forms an opening 131 communicating with the inner lumen 12. In one embodiment, the cutting portion 13 includes a distal end 132 and a proximal end 133, the proximal end 133 being a proximal-pointing tip structure, with an axial distance between the proximal end 133 and the distal end 132. The proximal end 133 of the cutting portion 13 is formed by the proximal end of a mesh structure 11 located at the nearest end. A straight line L passing through the proximal end 133 and the distal end of the thrombectomy stent 10 extends axially along the thrombectomy stent 10. When the thrombectomy stent 10 is located within the blood vessel and the restraining force acting on the thrombectomy stent 10 is released, the thrombectomy stent 10 can self-expand and radially unfold, thereby allowing the cutting portion 13 to adhere to the vessel wall.

[0032] Please see Figure 1 , Figure 2 and Figure 5A In one embodiment, the connection portion 112 between the drive wire 20 and the tack bracket 10 is located distal to the distal end 132. In other embodiments, the axial distance between the connection portion 112 and the distal end 132 is zero. That is, the connection portion 112 and the distal end 132 are radially opposite each other. The connection portion 112 is a point on the mesh structure 11, and the connection portion 112 is located at the intersection of two mesh rods 111, or between the two ends of the mesh rods 111.

[0033] exist Figure 1 In the illustrated embodiment, the connecting portion 112 is located on a straight line L passing through the proximal end 133 and the distal end of the thrombectomy bracket 10, such that the minimum circumferential length between the connecting portion 112 and the proximal end 133 is zero. In other embodiments, the connecting portion 112 is circumferentially offset from the straight line L, i.e., the connecting portion 112 is circumferentially offset relative to the proximal end 133, and the minimum circumferential length between the connecting portion 112 and the proximal end 133 is less than the minimum circumferential length between the connecting portion 112 and the distal end 132, and the minimum circumferential length between the connecting portion 112 and the proximal end 133 does not exceed 10 mm.

[0034] Please see Figure 1 The drive wire 20 is a flexible component, and the distal end of the drive wire 20 is connected to the thrombectomy bracket 10 at the connection part 112.

[0035] Please see Figure 1 and Figure 5A The thrombectomy device 100 also includes a support structure 40, one end of which is connected to the connection portion 112, and the other end is connected to the proximal end portion 133. The axial shortening rate of the support structure 40 does not exceed 0.1, so that when the support structure 40 is subjected to axial compressive force, the axial length shortening of the support structure 40 is small, thereby providing axial support between the connection portion 112 and the proximal end portion 133. The axial shortening rate can be measured by the following method: when the support structure 40 is not subjected to external force, the axial length of the support structure 40 is a. An axial compressive force is applied to the support structure 40, causing the axial length of the support structure 40 to shorten. When the axial length of the support structure 40 cannot be shortened further, the axial length of the support structure 40 is measured as b. The axial shortening rate of the support structure 40 is (ab) ÷ a × 100%. It should be noted that in the above measurement method, "the axial length of the support structure 40 cannot be shortened further" means that the axial length of the support structure 40 no longer shortens without deformation in the direction perpendicular to the axis of the support structure 40.

[0036] During the thrombectomy process using the thrombectomy device 100, the cutting portion 13 of the thrombectomy stent 10 is first positioned distal to the thrombus. The restraining force acting on the thrombectomy stent 10 is then released, causing the stent 10 to self-expand, thereby bringing the cutting portion 13 into contact with the vessel wall. Since the cutting portion 13 is a circumferentially closed ring structure, it can conform to the vessel wall in a 360° circumferential direction. A tensile force is applied to the drive wire 20 to drive the thrombectomy stent 10 proximally, thereby cutting the thrombus on the vessel wall. The thrombus cut off by the cutting portion 13 enters the lumen 12 of the thrombectomy stent 10 through the opening 131 and is captured, thus being removed from the body by the thrombectomy stent 10.

[0037] Since the connection 112 between the drive wire 20 and the thrombectomy stent 10 is located at the distal end of the distal end 132 of the cutting section 13 or the axial distance between the drive wire 20 and the distal end 132 is zero, the drive wire 20 does not directly exert axial tension on the opening of the cutting section 13 during thrombectomy, thereby reducing the radial contraction of the opening of the cutting section 13. Furthermore, since the proximal end 133 of the cutting section 13 is a proximal-pointing tip structure, the resistance from the thrombus at the proximal end 133 is relatively small. Simultaneously, one end of the support structure 40 is connected to the connection 112, and the other end is connected to the proximal end 133, so that during thrombectomy, the support structure 40 supports the tip structure. When the tip structure passes through the thrombus, it helps to prevent the proximal end 133 from deforming and failing to effectively scrape away the thrombus, thereby improving the thrombectomy efficiency of the thrombectomy device 100.

[0038] The drive wire 20 is a flexible component. If the distal end of the drive wire 20 extends within the thrombectomy stent 10, its diameter can be smaller compared to the rigid connecting rod, thus occupying less space within the lumen 12 of the thrombectomy stent 10 and thus reducing the space occupied for thrombus accommodating. If the distal end of the drive wire 20 is located outside the thrombectomy stent 10, its diameter can be smaller compared to the rigid connecting rod, preventing it from occupying a large space when extending axially from the distal end to the proximal end, which would cause the corresponding part of the thrombectomy stent 10 to not adhere to the wall. This improves the efficiency of thrombus removal and also helps to prevent thrombus escape.

[0039] In one embodiment, the distal end of the drive wire 20 is connected to the thrombectomy stent 10, and the drive wire 20 extends proximally from the lumen 12 of the thrombectomy stent 10 after being wound around the mesh structure 11 of the thrombectomy stent 10. The winding of the drive wire 20 around the mesh structure 11 of the thrombectomy stent 10 helps improve the structural stability of the thrombectomy stent 10, thereby helping to mitigate deformation under tension. The drive wire 20 is a flexible component and will not damage the blood vessel wall.

[0040] In this embodiment, the drive wire 20 can be a flexible rope or a stainless steel wire with a certain degree of flexibility.

[0041] Please refer to it again. Figure 1 In this embodiment, the portion of the driving wire 20 within the length range of the thrombectomy stent 10 extends into the lumen 12 of the thrombectomy stent 10. Because the diameter of the driving wire 20 can be relatively small, it occupies less space within the lumen 12 of the thrombectomy stent 10, thus minimizing the space occupied by the thrombus. During the process of the driving wire 20 driving the thrombectomy stent 10 to remove the thrombus under tensile force, the portion of the driving wire 20 within the length range of the thrombectomy stent 10 extending into the lumen 12 of the thrombectomy stent 10 reduces contact between the driving wire 20 and the vessel wall, thereby avoiding damage to the vessel wall caused by the driving wire 20.

[0042] Please see Figure 1 and Figure 2 The thrombectomy stent 10 includes, from far to near, a first segment T1, a second segment T2, and a third segment T3.

[0043] Please see Figure 1 and Figure 2 The first segment T1 is conical and has a mesh structure. The end of the first segment T1 with a smaller diameter is located at the distal end, and the end with a larger diameter is located at the proximal end. The proximal end of the first segment T1 with a larger diameter is connected to the second segment T2. The first segment T1 has a conical inner cavity, and the end of the first segment T1 with a larger diameter is an open end, and the end with a smaller diameter is a closed end. This closed end is the closed end of the thrombectomy stent 10.

[0044] Please see Figure 1 and Figure 2 The second segment T2 has a mesh structure and is cylindrical with a cylindrical inner cavity open at both ends. The distal end of the second segment T2 is connected to the proximal end of the first segment T1. The end of the second segment T2 away from the first segment T1 is connected to the third segment T3. The connecting part 112 is located within the second segment T2. In this embodiment, because the second segment T2 is cylindrical, its sidewalls extend axially, resulting in strong axial support. When the driving wire 20 applies a driving force to the thrombectomy stent 10, placing the connecting part 112 within the second segment T2 reduces the risk of axial deformation of the thrombectomy stent 10 under the driving force. This reduces the risk of the thrombectomy stent 10 collapsing radially at the connecting part 112 due to axial deformation, and also reduces the risk of the mesh structure of the connecting part 112 causing the cutting part 13 to collapse inward and separate from the blood vessel wall.

[0045] Please see Figure 1 and Figure 2 The third section T3 has a grid structure, the cutting part 13 is located in the third section T3, and the far end of the third section T3 is connected to the second section T2.

[0046] The distal opening of the third segment T3 is the cutting section 13. The opening 131 of the cutting section 13 is elliptical or approximately elliptical. When the thrombectomy stent 10 passes through the venous valve, the cutting section 13 can act as a guide, which facilitates the passage of the thrombectomy stent 10 through the venous valve and avoids the cutting section 13 scratching the venous valve.

[0047] Please see Figure 5A ,exist Figure 5A In the embodiment shown, the number of mesh structures 11 between the connection portion 112 and the proximal end portion 133 is one.

[0048] Please see Figure 5AThe support structure 40 includes a first connecting rod 41, a second connecting rod 42, and a plurality of end-to-end support rods 43. Of the plurality of support rods 43, the farthest support rod 43 is connected to the first connecting rod 41, and the closest support rod 43 is connected to the second connecting rod 42. The end of the first connecting rod 41 furthest from the support rod 43 extends axially towards the far end and connects to the connection portion 112. The end of the second connecting rod 42 furthest from the support rod 43 extends axially towards the near end and connects to the near end portion 133. In its natural state, any two adjacent support rods 43 form an included angle θ. When the thrombectomy stent 10 is axially compressed, the included angle θ decreases, causing the adjacent two supports 43 to fold and abut together, thus providing better axial support for the support structure 40. During thrombectomy, when the drive wire 20 is driven by external force to cut the thrombus in the blood vessel, the support structure 40 reliably provides axial support between the connection portion 112 and the proximal end 133, thereby avoiding deformation of the tip structure and improving the thrombectomy efficiency of the thrombectomy device 100. When the thrombectomy stent 10 is axially stretched, the included angle θ increases, and while the thrombectomy stent 10 and the support structure 40 are axially elongated, their radial dimensions decrease, allowing the thrombectomy stent 10 to be inserted into the delivery catheter 50.

[0049] Please see Figure 6 In another embodiment, the support structure 70 includes a first straight rod segment 71, a second straight rod segment 72, and a wave segment 73. Both ends of the wave segment 73 are connected to the first straight rod segment 71 and the second straight rod segment 72, respectively. The end of the first straight rod segment 71 furthest from the wave segment 73 is connected to the connection portion 112, and the end of the second straight rod segment 72 furthest from the wave segment 73 is connected to the proximal end 133 of the cutting portion 13. Both the first straight rod segment 71 and the second straight rod segment 72 are straight rod structures, which improves the axial support performance of the support structure 40. The wave segment 73 can be folded together under axial compressive force to provide axial support, and it can be elongated under axial tensile force to facilitate the stretching of the thrombectomy bracket 10 for insertion into the delivery conduit 50.

[0050] Please see Figure 5A In one embodiment, both the first connecting rod 41 and the second connecting rod 42 are parallel to the axial central axis of the thrombectomy bracket 10. During the thrombectomy process, since both the first connecting rod 41 and the second connecting rod 42 are parallel to the axial central axis of the thrombectomy bracket 10, the axial support performance of the first connecting rod 41 and the second connecting rod 42 can be improved, thereby improving the support performance of the support structure 40.

[0051] Please see Figure 5AIn one embodiment, the diameters of the first connecting rod 41, the second connecting rod 42, and the support rod 43 are all larger than the diameter of the net rod 111, making the structural strength of the first connecting rod 41, the second connecting rod 42, and the support rod 43 greater than the structural strength of the net rod 111. This allows the support structure 40 to provide more reliable axial support between the connection portion 112 and the proximal end 133, thereby avoiding deformation of the tip structure and reducing the thrombectomy efficiency of the thrombectomy device 100.

[0052] The hardness of the first connecting rod 41, the hardness of the second connecting rod 42, and the hardness of the support rod 43 are all greater than the hardness of the net rod 111. This also allows the support structure 40 to provide more reliable axial support between the connection part 112 and the proximal end 133, thereby avoiding deformation of the tip structure and reducing the retrieval efficiency of the retrieval device 100.

[0053] Please refer to the following: Figure 5A and Figure 5B Among the multiple support rods 43, the axial distance between the farthest support rod 43 and the nearest support rod 43 is D1, and the axial distance between the far end of the first connecting rod 41 and the proximal end of the second connecting rod 42 is D2. The ratio of D1 to D2 ranges from 1 / 3 to 1 / 4, so that the length D1 of the multiple support rods 43 is set within a small range. During the process of the drive wire 30 driving the thrombectomy bracket 10 to perform thrombectomy, the axial shortening of the support structure 40 is small, thereby increasing the axial support of the support structure 40 to avoid deformation of the tip structure. At the same time, it also makes it easier for the thrombectomy bracket 10 to be stretched and inserted into the delivery conduit 50.

[0054] Please see Figure 7 In one embodiment, there are multiple support structures 40. There are also multiple mesh structures 11 between the connecting portion 112 and the proximal end portion 133, with each mesh structure 11 extending axially. Specifically, a mesh rod 111 is provided between the connecting portion 112 and the proximal end portion 133, so that the connecting portion 112 and the proximal end portion 133 are located on different mesh structures 11. Each mesh structure 11 corresponds one-to-one with a multiple support unit 40, and one support structure 40 is provided on each mesh structure 11. During thrombectomy, the multiple support structures 40 cooperate with each other to improve the axial support between the connecting portion 112 and the proximal end portion 133.

[0055] exist Figure 7In the illustrated embodiment, in the farthest support structure 40, the end of the first connecting rod 41 furthest from the support rod 43 is connected to the connecting portion 112, and the end of the second connecting rod 42 furthest from the support rod 43 is connected to the intersection point of the near end of its grid structure 11. In the nearest support structure 40, the end of the second connecting rod 42 furthest from the support rod 43 is connected to the near end 133, and the end of the first connecting rod 41 furthest from the support rod 43 is connected to the intersection point of the far end of the nearest grid structure 11.

[0056] exist Figure 7 In the embodiment shown, the mesh of the mesh structure 11 between the connecting portion 112 and the proximal end 133 of the cutting portion 13 is smaller than the mesh of the mesh structure of other parts of the thrombectomy bracket 10, so that more meshes can be distributed between the connecting portion 112 and the proximal end 133, thereby improving the structural strength of the part between the connecting portion 112 and the proximal end 133 in the thrombectomy bracket 10, which helps to avoid deformation of the tip structure during thrombectomy, thereby improving the thrombectomy efficiency of the thrombectomy device 100.

[0057] Please see Figure 7 In one embodiment, the first connecting rod 41 and the second connecting rod 42 are collinear. During thrombectomy, when the drive wire 20 applies a driving force to the thrombectomy stent 10, the mesh structure 11 of the thrombectomy stent 10 located between the connecting portion 112 and the proximal end 133 is subjected to axial compression under the combined action of the driving force applied by the drive wire 20 and the resistance of the thrombus. This causes the mesh structure 11 to apply an axial compressive force to the support structure 40 connected to it. The line connecting the force point X of the farthest support rod 43 and the force point Y of the nearest support rod 43 in the support structure 40 is parallel to the axial central axis of the thrombectomy stent 10. Since the axial compressive force between the connecting part 112 and the proximal end 133 is an axial force, that is, the direction of the axial compressive force is parallel to the straight line L and the axis of the thrombectomy stent 10, the line connecting the force point X and the force point Y is parallel to the axis of the thrombectomy stent 10. This can prevent the foldable structure formed by multiple struts 43 from rotating clockwise or counterclockwise under the action of axial compressive force, which would lead to a decrease in the axial support of the foldable structure. In turn, it can reduce the excessive radial inward arching of the thrombectomy stent 10 between the connecting part 112 and the proximal end 133 due to axial deformation, thereby preventing the near-cutting part 13 from bending and deforming and separating from the blood vessel wall.

[0058] Please see Figure 1 and Figure 2 The thrombectomy bracket 10 also includes a collar 14, which is connected to the proximal end 133 of the cutting section 13 via a connecting rod 15.

[0059] Please see Figure 1 and Figure 2The thrombectomy device 100 also includes a push rod 30, which is connected to the proximal end of the thrombectomy stent 10. The push rod 30 is a hollow tubular structure, and its distal end is connected to a collar 14, thereby connecting to the proximal end 133 of the cutting section 13 via the collar 14 and the connecting rod 15. This allows the push rod 30 to apply force to the thrombectomy stent 10, thereby pushing the thrombectomy stent 10 to the distal end of the thrombus during the thrombectomy process.

[0060] Please continue reading. Figure 1 and Figure 2 The thrombectomy device also includes a push rod 60, which is a hollow tubular structure. The distal end of the push rod 60 is connected to the distal end of the thrombectomy bracket 10, and the proximal end of the push rod 60 extends proximally from the inner cavity 12 of the thrombectomy bracket 10. The push rod 60 is slidably inserted into the inner cavity of the push rod 30, and the proximal end of the push rod 60 protrudes from the proximal end of the push rod 30.

[0061] When loading the thrombectomy stent 10, a force is applied by at least one of the push rod 60 and the push rod 30, causing the distal ends of the push rod 60 and the push rod 30 to move away from each other, thereby applying a binding force to the thrombectomy stent 10, causing the mesh rods 111 of each mesh structure 11 to move closer together, and increasing the axial length of each mesh structure 11, thereby constraining the thrombectomy stent 10 to a state with a smaller radial dimension, so as to facilitate the subsequent loading of the thrombectomy stent 10 with a smaller radial dimension into the delivery conduit 50.

[0062] During the process described above, as the distal end of the operating rod 60 and the distal end of the pushing rod 30 move away from each other, the mesh rods 111 of the mesh structure 11 move closer to each other, and the axial length of the mesh structure 11 increases. When the support structure 40 is subjected to the axial tensile force of the mesh structure 11 and the mesh structure 11 connected to it, it can be stretched axially and elongated along the axial direction, which makes the radial dimension of the thrombectomy bracket 10 smaller when constrained, which is beneficial for the subsequent insertion of the thrombectomy bracket 10 into the delivery conduit 50.

[0063] Please see Figure 1The thrombectomy device 100 also includes a delivery catheter 50, which is slidably fitted onto a push rod 30 for loading and delivering the thrombectomy stent 10 within the patient's blood vessel. During loading the thrombectomy stent 10, the distal ends of the push rod 30 and the push rod 60 are first moved apart to constrain the thrombectomy stent 10 to a smaller radial dimension. Then, the delivery catheter 50 is moved relative to the thrombectomy stent 10, causing the delivery catheter 50 to fit onto the thrombectomy stent 10. This radially compresses the thrombectomy stent 10 to the loading size and places it within the lumen of the delivery catheter 50 for delivery within the patient's blood vessel. During loading the thrombectomy stent 10, a tensile force is applied to the thrombectomy stent 10 via the push rod 30, allowing the thrombectomy stent 10 to be compressed and loaded within the lumen of the delivery catheter 50. After the delivery catheter 50 delivers the thrombectomy stent 10 to the target site (e.g., the cutting portion 13 is located distal to the thrombus), the delivery catheter 50 is slid proximally relative to the thrombectomy stent 10 or the stent 10 is pushed out of the delivery catheter 50 by the push rod 30 to release the thrombectomy stent 10 from the delivery catheter 50, thereby removing the radial compressive force applied by the delivery catheter 50 to the thrombectomy stent 10. During the proximal sliding of the delivery catheter 50 to release the thrombectomy stent 10, the push rod 30 applies a distal pushing force to the thrombectomy stent 10 to prevent the thrombectomy stent 10 from being driven by the delivery catheter 50 and moving synchronously with it, thereby allowing the thrombectomy stent 10 to move relative to the delivery catheter 50 and be released from the lumen of the delivery catheter 50. After the radial restraint force of the delivery catheter 50 on the thrombectomy stent 10 is removed, the thrombectomy stent 10 can expand radially to a radially extended state, so that the cutting part 13 fits against the blood vessel wall. When the driving force is applied to the thrombectomy stent 10 through the drive wire 20 and the push rod 30 to move the thrombectomy stent 10 proximally, the cutting part 13 can cut the thrombus on the blood vessel wall.

[0064] When the delivery catheter 50 radially compresses the thrombectomy stent 10, the mesh rods 111 of the mesh structure 11 of the thrombectomy stent 10 move closer together, and the axial length of the mesh structure 11 increases. The mesh structure 11, connected to the support structure 40, applies an axial tensile force to the support structure 40 during axial elongation. Because the support structure 40 can be axially stretched and elongated under axial tensile force, the loading size of the thrombectomy stent 10 is smaller, thus resulting in a smaller outer diameter of the delivery catheter 50 carrying the thrombectomy stent 10. When the outer diameter of the delivery catheter 50 is smaller, only a small puncture incision is needed in the patient's body to allow the delivery catheter 50 to enter the blood vessel through the puncture incision; the smaller the size of the puncture incision, the less damage is caused to the patient's body.

[0065] It should be noted that in other embodiments, when the thrombectomy bracket 10 in the radially extended state is inserted into the delivery conduit 50, it is not necessary to constrain the thrombectomy bracket 10 to a state with a smaller radial dimension by moving the distal end of the push rod 60 away from the distal end of the push rod 30. Instead, the delivery conduit 50 is directly operated to fit over the thrombectomy bracket 10, thereby inserting the thrombectomy bracket 10 into the inner cavity of the delivery conduit.

[0066] In this embodiment, when the external force acting on the support structure 40 is removed, the angle θ formed by any two adjacent rods 43 is restored to the size when the support structure 40 is not subjected to external force.

[0067] Please see Figure 1 In one embodiment, after the distal end of the drive wire 20 is connected to the second segment T2 of the thrombectomy stent 10, the proximal end of the drive wire 20 extends proximally out of the body along the inner lumen of the delivery catheter 50, so that the operator can operate the drive wire 20 and thereby apply a driving force to the thrombectomy stent 10 through the drive wire 20.

[0068] In another embodiment, after the distal end of the drive wire 20 is connected to the second segment T2 of the thrombectomy bracket 10, the proximal end of the drive wire 20 can extend proximally out of the body along the inner cavity of the push rod 30.

[0069] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] The above description discloses only preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A thrombus removal device, characterized in that, include: A thrombectomy stent, the thrombectomy stent having an inner cavity, the thrombectomy stent including a cutting portion located at the proximal end, the cutting portion having an opening communicating with the inner cavity, the cutting portion including a distal end and a proximal end, the proximal end being a pointed tip structure pointing proximally; A drive wire, the distal end of which is connected to the thrombectomy bracket, and the connection point between the drive wire and the thrombectomy bracket is located at the distal end of the distal end or the axial distance between the connection point and the distal end is zero. A support structure, one end of which is connected to the connecting portion and the other end of which is connected to the proximal end.

2. The thrombectomy device as described in claim 1, characterized in that, The thrombectomy stent comprises multiple interconnected grid structures, each grid structure being polygonal, with the proximal end of the nearest grid structure forming the proximal end of the cutting portion. The support structure includes a first connecting rod, a second connecting rod, and multiple end-to-end support rods. Among the multiple support rods, the farthest support rod is connected to the first connecting rod, and the nearest support rod is connected to the second connecting rod. The end of the first connecting rod furthest from the support rod extends axially towards the distal end and connects to the connecting portion. The end of the second connecting rod furthest from the support rod extends axially towards the proximal end and connects to the proximal end. Both the first connecting rod and the second connecting rod are parallel to the axial central axis of the thrombectomy stent. In its natural state, any two adjacent support rods form an angle θ. When the thrombectomy stent is axially stretched, the angle θ increases.

3. The thrombectomy device as described in claim 2, characterized in that, When there are multiple axially extending mesh structures between the connecting part and the proximal end of the cutting part, there are multiple support structures, and the multiple support structures correspond one-to-one with the multiple mesh structures, with one support structure provided on each mesh structure.

4. The thrombectomy device as described in claim 3, characterized in that, The connection portion and the proximal end of the cutting portion have multiple axially extending mesh structures, and the mesh size of the mesh structure is smaller than that of the mesh structures of other parts of the thrombectomy bracket.

5. The thrombectomy device as described in claim 2, characterized in that, Each of the grid structures includes multiple interconnected poles, the diameters of the first connecting pole and the second connecting pole, as well as the diameter of the support pole, are all larger than the diameter of the grid pole.

6. The thrombectomy device as described in claim 2, characterized in that, Each of the grid structures includes multiple interconnected poles, the hardness of the first connecting pole and the second connecting pole, and the hardness of the support pole are all greater than the hardness of the grid pole.

7. The thrombectomy device as described in claim 2, characterized in that, Among the plurality of support rods, the axial distance between the farthest support rod and the nearest support rod is D1, the axial distance between the far end of the first connecting rod and the near end of the second connecting rod is D2, and the ratio of D1 to D2 is in the range of 1 / 3 to 1 / 4.

8. The thrombectomy device as described in claim 1, characterized in that, The thrombectomy bracket includes multiple interconnected mesh structures, each mesh structure being polygonal, with the proximal end of the nearest mesh structure forming the proximal end of the cutting portion. The support structure includes a first straight rod segment, a second straight rod segment, and a wave segment. The two ends of the wave segment are respectively connected to the first straight rod segment and the second straight rod segment, and the end of the first straight rod segment away from the wave segment is connected to the connecting portion. The end of the second straight rod segment away from the wave segment is connected to the proximal end of the cutting portion.

9. The thrombectomy device as described in claim 1, characterized in that, The thrombectomy stent comprises a first segment, a second segment, and a third segment from distal to proximal. The first segment is conical, and the proximal end of the first segment with a larger diameter is connected to the second segment. The second segment is cylindrical, and the end of the second segment furthest from the first segment is connected to the third segment. The cutting part is located within the third segment, and the connecting part is located within the second segment.

10. The thrombectomy device as described in claim 1, characterized in that, The thrombectomy device further includes a push rod and a top rod. The push rod is a tubular structure. The distal end of the push rod is fixedly connected to the proximal end of the cutting part. The distal end of the top rod is connected to the distal end of the thrombectomy bracket. The top rod is slidably inserted into the inner cavity of the push rod, and the proximal end of the top rod protrudes from the proximal end of the support rod.

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