Thrombectomy system

Abstract

The application provides a thrombus extraction system, which comprises a stent and a delivery device. The stent comprises a plurality of sub-stents connected in sequence along an axial direction, and each sub-stent has a contracted state and an expanded state. At least one sub-stent is provided with an elastic element along the axial direction. The delivery device comprises a control wire and a push rod. The proximal end of the stent is connected to the distal end of the push rod. The control wire passes through all the sub-stents and the elastic elements in the sub-stents in sequence and extends towards the proximal end. The control wire can control the transformation of the sub-stents between the contracted state and the expanded state. The application utilizes the influence of the contraction or recovery of the elastic element on the contracted state or the expanded state of the sub-stent to control the contraction or expansion degree of the sub-stent, so that the radial supporting force of the stent is not too large or insufficient, and the stent cannot be matched with the blood vessel. By changing the elastic coefficient of the elastic element, the expansion and contraction sequence of different sub-stents can be controlled, the last sub-stent that is contracted can be used to recover the escaped thrombus, and the recanalization rate of the blood vessel is increased.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a thrombectomy system. Background Technology

[0002] Acute stroke is the third leading cause of death and the leading cause of disability in adults. Ischemic stroke accounts for approximately 85% of acute strokes. Ischemic stroke is mainly caused by embolism of larger blood vessels (diameter > 2 mm), with a mortality rate ranging from 53% to 92%. Currently, the main treatment options for embolism are mechanical thrombectomy and thrombolysis.

[0003] Mechanical thrombectomy primarily involves puncturing the femoral artery, inserting instruments through the blood vessel to the site of the blockage, and then removing the thrombus using the instruments or a catheter, thereby restoring blood flow to the vessel. Compared to pharmacolytic thrombolysis, mechanical thrombectomy significantly improves the rate of vascular recanalization.

[0004] However, current thrombectomy stent designs typically involve cutting a perforated structure into a tubular material, using the stent's wave-like structure to cut the thrombus while simultaneously embedding it within the thrombus. Retraction of the stent then removes the thrombus. Existing thrombectomy stents are of uniform diameter, making it impossible to perfectly match the blood vessel. This can easily result in excessive or insufficient radial support force released within the vessel, leading to damage to the vessel wall or failure to remove the thrombus. Furthermore, the tubular structure of current thrombectomy stents means that fragmented thrombi cannot be effectively removed, easily escaping to distal vessels and causing secondary embolism.

[0005] Therefore, a new thrombectomy system is needed to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a thrombectomy system to solve at least one of the problems of how to avoid excessive or insufficient radial support force of the stent and thrombus escape.

[0007] To solve the above-mentioned technical problems, the present invention provides a thrombectomy system, comprising: a support and a delivery device;

[0008] The support includes a plurality of sub-supports connected sequentially along the axial direction, and the sub-supports have a contracted state and an expanded state; wherein, at least one of the sub-supports is provided with an elastic element along the axial direction.

[0009] The delivery device includes a control wire and a push rod; the proximal end of the support is connected to the distal end of the push rod; the control wire passes sequentially through all the sub-supports and the elastic elements within the sub-supports and extends proximally, and the control wire can control the sub-supports to change between the contracted state and the expanded state.

[0010] Optionally, in the aforementioned thrombectomy system, the opposite ends of the sub-support are fixed by positioning elements, and the positioning elements are provided with channels for the control wire to pass through.

[0011] Optionally, in the thrombectomy system, the positioning element connects two adjacent sub-supports.

[0012] Optionally, in the aforementioned thrombectomy system, the bracket is integrally woven from braided wire, and a positioning element for fixing the end of the sub-bracket is provided between two adjacent sub-brackets. The positioning element has a channel for the control wire to pass through.

[0013] Optionally, in the described thrombectomy system, the positioning element is a coil or a tube.

[0014] Optionally, in the aforementioned thrombectomy system, all of the sub-supports are provided with the elastic element along the axial direction.

[0015] Optionally, in the thrombectomy system, the elastic coefficients of the elastic elements within all the sub-supports may be the same or partially different.

[0016] Optionally, in the thrombectomy system, the order in which all the sub-stents change from the contracted state to the expanded state is in ascending order of the sum of the elastic coefficients of the sub-stents and the corresponding elastic elements.

[0017] Optionally, in the thrombectomy system, the order in which all the sub-stents change from the expanded state to the contracted state is in descending order of the sum of the elastic coefficients of the sub-stents and the corresponding elastic elements.

[0018] Optionally, in the thrombectomy system, all the sub-supports are made of the same material, or at least some of the sub-supports are made of different materials.

[0019] Optionally, in the thrombectomy system, the sum of the elastic coefficient of the sub-support located at the distal end of the support and the elastic coefficient of the corresponding elastic element is minimized.

[0020] Optionally, in the described bolt removal system, the elastic element is a spring.

[0021] Optionally, in the thrombectomy system, the outer surface of the distal end of the push rod is provided with a radiopaque mark, and the proximal end of the bracket is fixed to the distal end of the push rod by the radiopaque mark.

[0022] Optionally, in the thrombectomy system, the delivery device further includes a sleeve fitted over the outer surface of the developing mark.

[0023] Optionally, in the thrombectomy system, the delivery device further includes a distal connector, and the distal end of the bracket is connected to the distal connector.

[0024] Optionally, in the thrombectomy system, the distal connector is provided with a contrast marker.

[0025] Optionally, in the described thrombectomy system, the developing marker is a developing spring or a developing sleeve.

[0026] Optionally, in the thrombectomy system, the distal end of the control wire is connected to the distal connector.

[0027] Optionally, in the thrombectomy system, the push rod has a channel, and the proximal end of the control wire passes through the channel; or, the proximal end of the control wire is located outside the push rod.

[0028] Optionally, in the thrombectomy system, the delivery device further includes a handle; the handle is connected to the proximal end of the push rod; wherein the handle is provided with a control element, the control element is connected to the proximal end of the control wire, and the control element controls the control wire to move proximal or distally.

[0029] Optionally, in the described thrombectomy system, the control element is a slider, which is slidably connected to the handle.

[0030] In summary, the thrombectomy system provided by this invention utilizes an elastic element within the sub-stent. A control wire alters the contraction or expansion state of the sub-stent, causing deformation of the elastic element. This deformation influences the degree of contraction or expansion of the sub-stent, thereby controlling its extent and preventing excessive or insufficient radial support force that would hinder its fit with the blood vessel. Furthermore, by altering the elastic coefficient of the elastic element and / or the elastic coefficient of the sub-stent, the order of expansion and contraction of different sub-stents can be controlled. This system not only adapts to blood vessel segments with different diameters but also utilizes the bulging state of the last contracted sub-stent to recover escaped thrombi, increasing vascular recanalization rates. Therefore, this invention not only avoids excessive or insufficient radial support force and controls the degree of stent expansion and contraction but also prevents thrombus escape and improves thrombectomy effectiveness. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a thrombectomy system according to an embodiment of the present invention;

[0032] Figure 2-8 This is a schematic diagram of the movement of the sub-support expanding as pulled by the slider in an embodiment of the present invention;

[0033] The reference numerals in the attached figures are explained as follows:

[0034] 101 - Sub-bracket; 102 - Elastic element; 103 - Positioning element;

[0035] 201-Push rod; 202-Control wire; 203-Remote connector; 204-Developing mark; 205-Handle; 206-Control element. Detailed Implementation

[0036] To make the objectives, advantages, and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to facilitate and clearly illustrate the objectives of the embodiments of the present invention. Furthermore, the structures shown in the drawings are often part of the actual structures. In particular, different figures may emphasize different aspects and sometimes use different scales. It should also be understood that, unless specifically stated or indicated, the terms "first," "second," "third," etc., in the specification are only used to distinguish the various components, elements, steps, etc., in the specification, and are not used to indicate the logical or sequential relationships between the various components, elements, steps, etc.

[0037] In this article, "proximal" and "distal" are defined as follows: "distal" usually refers to the end of the medical device that first enters the patient's body during normal operation, while "proximal" usually refers to the end of the medical device that is closest to the operator during normal operation.

[0038] Please see Figure 1 This embodiment provides a thrombectomy system, including: a support and a delivery device; the support includes a plurality of sub-supports 101 connected sequentially along the axial direction, the sub-supports 101 having a contracted state and an expanded state; wherein, at least one of the sub-supports 101 has an elastic element 102 arranged axially within it; the delivery device includes a push rod 201 and a control wire 202; the proximal end of the support is connected to the distal end of the push rod 201; the control wire 202 passes sequentially through all the sub-supports 101 and the elastic element 102 within the sub-supports 101 and extends proximally, the control wire 202 being able to control the sub-supports 101 to change between the contracted state and the expanded state.

[0039] As can be seen, the thrombectomy system provided in this embodiment achieves control over the degree of contraction or expansion of the sub-stent 101 by incorporating an elastic element 102 within the sub-stent 101 and utilizing a control wire 202 to alter the contraction or expansion state of the sub-stent 101. This deformation of the elastic element 102 influences the degree of contraction or expansion of the sub-stent 101, thereby preventing excessive or insufficient radial support force that would hinder its compatibility with the blood vessel. Furthermore, by altering the elastic coefficient of the elastic element 102 and / or the elastic coefficient of the sub-stent 101, the order of expansion and contraction of different sub-stents 101 can be controlled. This system not only adapts to blood vessel segments with different diameters but also utilizes the bulging state of the last contracted sub-stent 101 to recover escaped thrombi, increasing the vascular recanalization rate. Therefore, this embodiment not only avoids excessive or insufficient radial support force of the stent and controls the degree of expansion and contraction, but also prevents thrombus escape and improves the thrombectomy effect.

[0040] The following is in conjunction with the appendix Figure 1-8 This embodiment provides a detailed description of the thrombectomy system.

[0041] Please see Figure 1 The stent provided in this embodiment is a mesh structure with multiple segments, and each segment is a sub-stent 101. The sub-stent 101 has good flexibility and elasticity, and can deform under stress, thus exhibiting both contracted and expanded states. The multiple sub-stents 101 can be integrally woven from braided filaments, or each sub-stent 101 can be independently woven and sequentially connected along the axial direction to form the stent. Therefore, all sub-stents 101 can be made of the same material, partially different materials, or all different materials. The purpose is to allow sub-stents 101 made of different materials to have different elastic coefficients, so as to control the order of expansion or contraction of different sub-stents 101 and improve the stent's adaptability to blood vessel segments with different diameters. The materials of the sub-stents 101 include, but are not limited to, nickel-titanium alloy, cobalt-chromium alloy, DFT material, or tantalum alloy. Furthermore, the structure of the stent can be a single-layer, one-to-one, two-to-one, or two-to-two structure; it can be double-layered; or it can be a multi-layered or composite structure of several structures. like Figure 1 The example shows that the number of sub-stents 101 is 3, but it can also be 2, 4, 5, or 6, etc. This embodiment does not limit the specific number of sub-stents 101, nor does it limit the axial length of the sub-stents 101. The axial length of each sub-stent 101 can be the same or different. Different lengths of stents can be selected according to different lesion conditions.

[0042] At least one of the sub-stents 101 in the stent has an elastic element 102 arranged axially within it. The elastic element 102 is used to constrain the expansion or compression of the sub-stent 101, preventing damage to the sub-stent 101 due to excessive expansion or compression, and preventing the radial support force of the sub-stent 101 from being too large or too small, thus failing to fit with the blood vessel. Preferably, all the sub-stents 101 have an elastic element 102 within them, so as to control the expansion degree of each sub-stent 101. The opposite ends of the elastic element 102 are respectively connected to the opposite ends of the corresponding sub-stent 101, serving to fix the position of the elastic element 102 and to cause the sub-stent 101 to expand or contract when the elastic element 102 is compressed or recovers. Alternatively, the position of the elastic element 102 may be defined solely by the passage of the control wire 202. In other words, since the two ends of the elastic element 102 are not connected to the two ends of the corresponding sub-stent 101, when the sub-stent 101 expands or contracts under stress, a force is applied to the elastic element 102, causing the elastic element 102 to deform and apply a reaction force to the sub-stent 101. This influences the degree of expansion and contraction of the sub-stent 101, preventing damage to the sub-stent 101 due to excessive expansion or compression, and preventing the radial support force of the sub-stent 101 from being too large or too small, thus ensuring proper fit with the blood vessel.

[0043] Furthermore, when the opposite ends of the elastic element 102 are not connected to the opposite ends of the corresponding sub-support 101, the length of the elastic element 102 in its natural state can be greater than or less than the length of the sub-support 101 in its contracted state; the length of the elastic element 102 when compressed to its shortest length is less than or equal to the length of the sub-support 101 in its expanded state. Preferably, the elastic element 102 is a spring capable of elastic deformation.

[0044] The opposite ends of the sub-support 101 are fixed by positioning members 103, and the positioning members 103 have channels for the control wire 202 to pass through. Only one positioning member 103 is needed to connect two adjacent sub-supports 101. Furthermore, when the elastic member 102 is connected to the opposite ends of the sub-support 101, the opposite ends of the elastic member 102 within the sub-support 101 can also be connected to the positioning member 103. Further, the positioning member 103 is a coil or a tube. Optionally, the positioning member 103 is a coil formed by winding metal wire, such as a ring formed by winding platinum-tungsten wire, or a thin-walled tube. Of course, the material of the positioning member 103 can also be a radiopaque material, such as gold, platinum, or tantalum, or a radiopaque polymer material. The positioning element 103 can also be composed of inner and outer tubes. The end of the sub-support 101 and the end of the elastic element 102 can be fixedly connected between the inner tube and the outer tube, and the connection method includes, but is not limited to, welding, hot melting or bonding.

[0045] Therefore, the positioning member 103 not only connects the sub-supports 101 but also connects the sub-supports 101 to the elastic members 102 within them. This allows the elastic members 102 to influence the relative positions of the sub-supports 101 as they compress or recover, thus controlling their expansion or compression. Furthermore, the positioning member 103 ensures the cylindrical pair freedom of the control wire 202, allowing it to move and twist freely axially within the positioning member 103 and the sub-supports 101, improving the stability of the thrombectomy system. Simultaneously, the positioning member 103 securely restrains the two ends of the sub-supports 101, preventing excessive deformation.

[0046] Please continue reading. Figure 1The conveying device includes a push rod 201, a control wire 202, and a distal connector 203. The push rod 201 primarily functions as a pusher, transmitting the pushing force at the proximal end. Therefore, the push rod 201 can be a metal tube with high rigidity, and its material includes, but is not limited to, stainless steel, cobalt-chromium alloy, or nickel-titanium alloy. The push rod 201 can also be a closed tube or a cut sodium hydroxide tube. The support is positioned between the push rod 201 and the distal connector 203. That is, the proximal end of the support is connected to the distal end of the push rod 201, and the distal end of the support is connected to the distal connector 203. Optionally, the distal and proximal ends of the support are directly connected to the distal connector 203 and the push rod 201. Alternatively, the positioning element 103 is connected to both the distal and proximal ends of the support, connecting the distal connector 203 and the push rod 201 via the positioning element 103. Furthermore, when the distal connector 203 is connected via the positioning member 103, the outer diameter of the positioning member 103 is smaller than the outer diameter of the distal connector 203. This is to ensure the tension stability of the control wire 202 and to prevent the distal connector 203 from dislodging from its original position and becoming embedded in the positioning member 103 due to the excessive outer diameter of the positioning member 103, thus disrupting the bolt removal system.

[0047] Furthermore, to control the delivery process, a development mark 204 is provided on the outer surface of the distal end of the push rod 201, and a development mark is also provided on the outer surface of the distal connector 203. The development mark includes, but is not limited to, a development spring or a development sleeve. The proximal end of the support is fixed to the distal end of the push rod 201 via the development mark 204. Furthermore, the delivery device also includes a sleeve (not shown) to be fitted over the development mark on the outer surface of the push rod 201 to protect the development mark 204. Simultaneously, the sleeve is made of a polymer material, which also serves as a lubricant, allowing the delivery device to be pushed with less force within the microcatheter, thus enhancing the device's bending capability.

[0048] The control wire 202 is used to control the expansion or compression of the sub-stent 101, preventing excessive or insufficient radial support force from hindering its fit with the blood vessel. The distal end of the control wire 202 is fixedly connected to the distal connector 203, allowing the distance between the distal connector 203 and the push rod 201 to be reduced or increased by pulling the control wire 202, thus changing the compression or expansion state of the stent. In other embodiments, the distal end of the control wire 202 may be directly connected to the distal end of the stent, or the distal end of the control wire 202 may be connected to the positioning member 103 at the distal end of the stent. The proximal end of the control wire 202 passes sequentially through all the sub-stents 101 and the elastic members 102 within each sub-stent 101, extending proximally. The push rod 201 has a channel, and the proximal end of the control wire 202 can be inserted into the push rod 201; or, the proximal end of the control wire 202 is located outside the push rod 201, that is, the proximal end of the control wire 202 does not extend into the push rod 201, but only extends from the proximal end of the bracket to the outside.

[0049] The conveying device further includes a handle 205 and a control element 206. The handle 205 is located at the proximal end of the push rod 201 for easy gripping by the operator. The handle 205 is equipped with the control element 206, which is connected to the proximal end of the control wire 202. The control element 206 controls the movement of the control wire 202 proximal or distal. Furthermore, the handle 205 is also equipped with axially arranged guide rails. The control element 206 is a slider connected to the guide rails and capable of sliding along them. Therefore, the operator can pull the control wire 202 by sliding the slider, thereby changing the shape of the sub-support 101 and the elastic element 102.

[0050] Furthermore, the elastic coefficients of the elastic elements 102 within all the sub-supports 101 are the same or partially different. Similarly, based on the material characteristics, the elastic coefficients of all the sub-supports 101 are also the same or partially different. Therefore, without considering other forces, when the slider is pulled, the elastic coefficients of the sub-supports 101 and the elastic elements 102 are the direct cause affecting the expansion or contraction of the sub-supports 101. Thus, based on the parallel connection relationship of the sub-supports 101 and the elastic elements 102 and F = kx, it can be known that the order in which all the sub-supports 101 change from the contracted state to the expanded state is the order in which the sum of the elastic coefficients of the sub-supports 101 and the corresponding elastic elements 102 increases. The order in which all the sub-supports 101 change from the expanded state to the contracted state is the order in which the sum of the elastic coefficients of the sub-supports 101 and the corresponding elastic elements 102 decreases.

[0051] Understandably, in the first scenario, when all sub-supports 101 are equipped with elastic elements 102, and the two ends of the elastic elements 102 are connected to the two ends of the sub-supports 101, pulling the slider causes each sub-support 101 and its corresponding elastic element 102 to experience the same tensile force as a whole. Furthermore, the sub-supports 101 and their corresponding elastic elements 102 produce the same deformation displacement. Therefore, the overall elastic coefficient is the sum of the elastic coefficients of the sub-supports 101 and the elastic coefficients of the elastic elements 102. Under the same tensile force, a smaller overall elastic coefficient makes deformation easier to occur. Conversely, under opposite forces, a larger overall elastic coefficient makes it easier to recover from deformation.

[0052] Similarly, in the second case, when both ends of the elastic element 102 are connected to both ends of the sub-support 101, and some sub-supports 101 contain the elastic element 102 while others do not, pulling the slider results in the elastic coefficient of the corresponding elastic element 102 being 0 for the sub-support 101 without the elastic element 102. Therefore, the sum of the elastic coefficient of the sub-support 101 and the coefficient of the corresponding elastic element 102 equals the elastic coefficient of the sub-support 101 itself. That is, comparing the elastic coefficient of the sub-support 101 without the elastic element 102 with the overall elastic coefficient of the sub-support 101 with the elastic element 102, it is still the case that a smaller elastic coefficient makes deformation easier, and a larger elastic coefficient makes recovery from deformation easier.

[0053] In the third case, when the elastic element 102 is not connected to either end of the sub-support 101, and the axial length of the elastic element 102 is less than the axial length of the sub-support 101 in its contracted state, regardless of whether the sub-support 101 contains the elastic element 102, pulling the slider will cause the sub-support 101 to deform independently first, while the corresponding elastic element 102 will not be affected by the force. During the stage when the sub-support 101 is subjected to tension alone, it is equivalent to the elastic coefficient of the corresponding elastic element 102 within the sub-support 101 being 0. Therefore, the sum of the elastic coefficient of the sub-support 101 and the coefficient of the corresponding elastic element 102 is the elastic coefficient of the sub-support 101 itself. Thus, comparing the overall elastic coefficient of the sub-support 101 and the corresponding elastic element 102 is equivalent to comparing the elastic coefficients of each individual sub-support 101. When all sub-supports 101 change from the contracted state to the expanded state, under the same tension, the smaller the elastic coefficient of each sub-support 101, the easier it is to deform. When the sub-support 101 expands to contact the elastic element 102, the sub-support 101 and the corresponding elastic element 102 can deform synchronously, as described in the first or second scenario. Similarly, the smaller the overall elastic coefficient of the sub-support 101 and the corresponding elastic element 102, the easier it is to deform. Conversely, when all the sub-supports 101 change from the expanded state to the contracted state, the sub-support 101 and the corresponding elastic element 102 still deform synchronously; therefore, the larger the overall elastic coefficient of the sub-support 101 and the corresponding elastic element 102, the easier it is to recover.

[0054] In the fourth case, when the elastic element 102 is not connected to both ends of the sub-support 101, and the axial length of the elastic element 102 is greater than or equal to the axial length of the sub-support 101 in the contracted state, the elastic element 102 abuts against the inner sides of both ends of the sub-support 101. In this case, the deformation of the sub-support 101 is the same as in the first or second case, as described above.

[0055] In summary, in the above four cases, the following rules are satisfied: The order in which all the sub-brackets 101 change from the contracted state to the expanded state is the order from small to large of the sum of the elastic coefficients of the sub-brackets 101 and the elastic coefficients of the corresponding elastic members 102. The order in which all the sub-brackets 101 change from the expanded state to the contracted state is the order from large to small of the sum of the elastic coefficients of the sub-brackets 101 and the elastic coefficients of the corresponding elastic members 102. Therefore, in this embodiment, this principle is used to control the expansion degree of different sub-brackets 101 and the expansion or contraction time, thereby avoiding the problem that the radial support force of the stent is too large or insufficient and cannot cooperate with the blood vessel. Based on this, the elastic coefficients of all the sub-brackets 101 and all the elastic members 102 may be equal, or some may be equal and some may not be equal, or all may be different. This embodiment does not make specific limitations on this and can be designed individually according to needs.

[0056] To facilitate understanding of the thrombectomy device provided in this embodiment, this embodiment takes the case where the elastic coefficients of all the sub-brackets 101 are the same and all the elastic members 102 are connected to both ends of the corresponding sub-brackets 101 as an example, and specifically introduces the thrombectomy system provided in this embodiment in three cases: the elastic coefficients of all the elastic members 102 are all different, the elastic coefficients of some of the elastic members 102 are the same, and the elastic coefficients of all the elastic members 102 are the same.

[0057] Please refer to Figure 1-4 , the elastic coefficients of the elastic members 102 in the sub-bracket 101a, the sub-bracket 101b, and the sub-bracket 101c are k1, k2, and k3 respectively, and k1 < k2 < k3. As Figure 2 shown, when the control element 206 is pulled in the V direction, without considering other acting forces, the three elastic members 102 are subjected to the same pulling force, and the elastic coefficients of all the sub-brackets 101 are the same. Since the elastic coefficient k1 of the elastic member 102 in the sub-bracket 101a is the smallest, the elastic member 102 in the sub-bracket 101a contracts first, and then the sub-bracket 101a expands accordingly. When the pulling force is further increased, as Figure 3 shown, since the elastic coefficient k2 of the elastic member 102 in the sub-bracket 101b is smaller than the elastic coefficient k3 of the elastic member 102 in the sub-bracket 101c, the elastic member 102 in the sub-bracket 101b contracts first, and then the sub-bracket 101b expands accordingly. When the pulling force is continuously increased, as Figure 4As shown, when the elastic member 102 in the sub-bracket 101c contracts, the sub-bracket 101c expands accordingly. It can be seen that the elastic member 102 with a smaller elastic coefficient starts to contract first, and the elastic member 102 with a larger elastic coefficient contracts later. Therefore, the expansion sequence of the sub-bracket 101 can be controlled by controlling the magnitude of the elastic coefficient to adapt to different vascular regions.

[0058] It can be understood that the elastic member 102 with a smaller elastic coefficient is more prone to deformation, and the amount of deformation will also be larger than that of the elastic member 102 with a larger elastic coefficient. Correspondingly, the greater the elastic deformation of the elastic member 102, the greater the expansion degree of the corresponding sub-bracket 101. Based on this, by adjusting the elastic coefficient of the elastic member 102, the radial expansion size of the sub-bracket 101 can be controlled. Compared with a stent that expands一次性膨胀开支架 (I'm not sure what this specific term means in English, you may need to correct it), the thrombectomy system provided in this embodiment can well avoid the damage to blood vessels caused by excessive radial supporting force of the stent and avoid the problem that the radial supporting force of the stent is insufficient and cannot cooperate with the blood vessels.

[0059] Similarly, when the control element 206 slides in the opposite direction of the V direction, that is, the force direction of the elastic member 102 is opposite, the compressed elastic member 102 begins to recover. Then the elastic member 102 with the smallest elastic coefficient recovers last, and the elastic member 102 with the largest elastic coefficient recovers first. Then the sub-bracket 101c recovers first, followed by the sub-bracket 101b, and finally the sub-bracket 101a. The recovery process is Figures 4 to 3 to Figures 2 to 1 . Among them, the sub-bracket 101a at the farthest end recovers last, and the bulging braided mesh can play a role in intercepting escaped thrombus to avoid the problem of thrombus falling at the distal end of the stent during the thrombectomy process and causing embolism blockage. Therefore, preferably, the sum of the elastic coefficients of the elastic member 102 of the sub-bracket 101 located at the distal end of the stent is the smallest.

[0060] Please refer to Figure 1 and 5 -6. The elastic coefficients of the elastic members 102 in the sub-bracket 101a, the sub-bracket 101b, and the sub-bracket 101c are k1, k2, and k3 respectively, and k2 < k1 = k3. As Figure 5As shown, when the control element 206 is pulled along the V direction, without considering other forces, the three elastic elements 102 are subjected to the same tension. Since the elastic coefficient k2 of the elastic element 102 in the sub-support 101b is the smallest, the elastic element 102 in the sub-support 101b contracts first, and the sub-support 101b expands accordingly. Because the elastic coefficient k1 of the elastic element 102 in the sub-support 101a is the same as the elastic coefficient k3 of the elastic element 102 in the sub-support 101c, and both are greater than the elastic coefficient k2 of the elastic element 102 in the sub-support 101b, the elastic elements 102 in the sub-supports 101a and 101c will simultaneously undergo slight contraction, or not contract at all. When the tension is further increased, such as... Figure 6 As shown, when the elastic elements 102 in sub-stents 101a and 101c contract simultaneously, the sub-stents 101a and 101c also expand simultaneously. Therefore, during the procedure, thrombus embedding can be achieved through the sub-stent 101b. After a period of time, approximately 5 minutes, the control element 206 is pulled, causing the sub-stents 101a and 101c to expand, thereby improving the vascular recanalization rate. Similarly, when the control element 206 slides in the opposite direction to the V direction, i.e., the force direction of the elastic element 102 is opposite, the compressed elastic element 102 begins to recover. The elastic element 102 with the largest elastic coefficient recovers first, and the elastic element 102 with the smallest elastic coefficient recovers last. Therefore, the sub-stents 101a and 101c at both ends recover first, and the sub-stent 101b in the middle recovers last. The recovery process is as follows: Figures 6 to 5 to Figure 1 .

[0061] Please see Figure 1 and 7 -8, the elastic coefficients of the elastic elements 102 in the sub-supports 101a, 101b, and 101c are k1, k2, and k3, respectively, and k1 = k2 = k3. For example... Figure 7-8 As shown, when the control element 206 is pulled along the V direction, neglecting other forces, the three elastic elements 102 experience the same tension. Since the elastic coefficients of the three elastic elements 102 are all the same, they contract simultaneously, causing the sub-supports 101a, 101b, and 101c to expand simultaneously. Similarly, when the control element 206 slides in the opposite direction of the V direction, i.e., the forces acting on the elastic elements 102 are opposite, the compressed elastic elements 102 begin to recover. Since the elastic coefficients of the three elastic elements are the same, they recover simultaneously, causing the sub-supports 101a, 101b, and 101c to recover simultaneously as well.

[0062] Furthermore, to avoid excessive tension on the elastic element 102, which could cause its deformation to exceed its maximum deformation and damage it, the deformation limit of all elastic elements 102 along the axial direction of the stent is greater than the maximum sliding distance of the slider 204. Also, since the corresponding sub-stent 101 will no longer deform after the elastic element 102 is compressed to its minimum value, i.e., it will no longer expand, excessive stent expansion can be avoided from damaging the blood vessel. And, at the initial position of the control element 206 sliding in the V direction, such as... Figure 1 As shown, all the elastic elements 102 do not undergo elastic deformation to avoid the sub-supports 101 bulging in the initial position, which would be detrimental to support transportation.

[0063] In summary, this embodiment provides a thrombectomy system. By incorporating an elastic element 102 within the sub-stent 101, and when the control element 206 slides, the control wire 202 enables deformation of both the sub-stent 101 and the elastic element 102. Under the influence of the elastic force of the elastic element 102, the degree of expansion and contraction of the sub-stent 102 is controlled, preventing excessive or insufficient radial support force that would prevent proper fit with the blood vessel. Furthermore, by altering the elastic coefficient of the elastic element 102 and / or the elastic coefficient of the sub-stent 101, the order of expansion and contraction of different sub-stents 101 can be controlled. This not only adapts to blood vessel segments with different diameters but also allows for the retrieval of escaped thrombi by utilizing the bulging state of the last contracted sub-stent 101, thereby increasing the vascular recanalization rate. Furthermore, the positioning element 103 can also ensure the degree of freedom of the cylindrical pair of the control wire 202, that is, ensure that the control wire 202 can move and twist freely axially within the positioning element 103 and the sub-stent 101, thereby improving the feasibility of the thrombectomy system. Therefore, the thrombectomy system provided in this embodiment can not only avoid excessive or insufficient radial support force of the stent and achieve control over the release and retraction of the stent, but also prevent thrombus escape and improve the thrombectomy effect.

[0064] Furthermore, it should be understood that although the present invention has been disclosed above with reference to preferred embodiments, these embodiments are not intended to limit the present invention. For any person skilled in the art, many possible variations and modifications can be made to the technical solutions of the present invention based on the disclosed technical content, or equivalent embodiments can be modified accordingly, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, shall still fall within the scope of protection of the present invention.

Claims

1. A thrombectomy system, comprising: The application relates to a stent and a delivery device. The stent comprises a plurality of sub-stents connected in sequence along an axial direction, and each sub-stent has a contracted state and an expanded state; at least one of the sub-stents is provided with an elastic member along the axial direction. The delivery device comprises a control wire and a push rod; the proximal end of the stent is connected to the distal end of the push rod; the control wire passes through all the sub-stents and the elastic members in the sub-stents in sequence and extends to the proximal end; the control wire can control the sub-stents to change between the contracted state and the expanded state; the elastic coefficients of the elastic members are different and / or the elastic coefficients of the sub-stents are different, so as to control the sequence of expansion and contraction of different sub-stents. The opposite ends of the sub-stents are fixed by positioning members, and the positioning members are provided with channels for the control wire to pass through. The positioning members connect adjacent two sub-stents.

2. The thrombectomy system of claim 1, wherein, The stent is integrally woven by braided wires, and a positioning member for fixing the end of the sub-stent is arranged between adjacent two sub-stents; the positioning member is provided with a channel for the control wire to pass through.

3. The thrombectomy system of claim 2, wherein, The positioning member is a coil or a tube.

4. The thrombectomy system of claim 1, wherein, The elastic members are arranged along the axial direction in all the sub-stents.

5. The thrombectomy system of any of claims 2-4, wherein, The elastic coefficients of the elastic members in all the sub-stents are the same or partially different.

6. The thrombectomy system of claim 1, wherein, The sequence of all the sub-stents changing from the contracted state to the expanded state is the sequence of the sum of the elastic coefficients of the sub-stents and the corresponding elastic members from small to large.

7. The thrombectomy system of claim 1, wherein, The sequence of all the sub-stents changing from the expanded state to the contracted state is the sequence of the sum of the elastic coefficients of the sub-stents and the corresponding elastic members from large to small.

8. The thrombectomy system of claim 1, wherein, The materials of all the sub-stents are the same, or at least part of the materials of the sub-stents are different.

9. The thrombectomy system of claim 1, wherein, The sum of the elastic coefficients of the sub-stent and the corresponding elastic member at the distal end of the stent is the smallest.

10. The thrombectomy system of claim 1, wherein, The elastic member is a spring.

11. The thrombectomy system of claim 1, wherein, The outer surface of the distal end of the push rod is provided with a developing mark, and the proximal end of the stent is fixed to the distal end of the push rod through the developing mark.

12. The thrombectomy system of claim 1, wherein, The delivery device further comprises a sleeve arranged on the outer surface of the developing mark.

13. The thrombectomy system of claim 1, wherein, The delivery device further comprises a distal end connector, and the distal end of the stent is connected to the distal end connector.

14. The thrombectomy system of claim 13, wherein, The distal end connector is provided with a developing mark.

15. The thrombectomy system of Claim 1, wherein, The developing mark is a developing spring or a developing sleeve.

16. The thrombectomy system of claim 15, wherein, The distal end of the control wire is connected to the distal end connector.

17. The thrombectomy system of either claim 13 or 16, wherein, The push rod is provided with a channel, and the proximal end of the control wire is arranged in the channel; or the proximal end of the control wire is arranged outside the push rod.

18. The thrombectomy system of claim 15, wherein, The delivery device further comprises a handle; the handle is connected to the proximal end of the push rod; the handle is provided with a control element connected to the proximal end of the control wire, and the control element controls the control wire to move to the proximal end or the distal end.

19. The thrombectomy system of Claim 1, wherein, The control element is a slider which is slidably connected to the handle.

20. The thrombectomy system of Claim 1, wherein, ​ 21. The thrombectomy system of claim 20, wherein, ​

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