A surface-modified vascular stent integrating development positioning and active anchoring

Abstract

The application provides a surface modification vascular stent integrating development positioning and active anchoring, and relates to the technical field of vascular stents. The vascular stent comprises a main stent and a development anchoring integrated part. The development anchoring integrated part comprises a development ring, an anchoring part and a linkage stent. The linkage stent is connected between the main stent and the development ring and is made of a first memory alloy material. The development ring has a segmented ring structure, and a gap between the development ring forms a tissue ingrowth gap for inducing vascular intimal tissue ingrowth. The anchoring part comprises an anchoring protrusion, and the anchoring protrusion comprises a tissue ingrowth cavity and a tissue ingrowth hole which are in communication with each other. After the development ring is radially expanded, the anchoring protrusion forms a mechanical anchoring with a blood vessel wall, and allows vascular intimal tissue to grow into the tissue ingrowth cavity through the tissue ingrowth hole to form a deep biological anchoring. Thus, the problems of unclear postoperative development and long-term displacement risk of the current vascular stent are solved.

Description

Technical Field

[0001] This application relates to the field of vascular stent technology, and in particular to a surface-modified vascular stent that integrates imaging positioning and active anchoring. Background Technology

[0002] A vascular stent is a mesh-like device implanted in a blood vessel. It expands or self-expands via balloon dilation to open narrowed or blocked vessels, restoring blood flow. It is widely used in interventional treatment of vascular diseases such as those in the coronary arteries, peripheral arteries, carotid arteries, and venous system. Traditional vascular stents are typically made of metal cut or woven using laser technology, and their surface can carry anti-proliferative drugs to inhibit intimal hyperplasia and reduce restenosis rates. These stents are not degraded or absorbed in the body and are classified as non-absorbable vascular stents. In contrast, bioresorbable vascular stents are made of biodegradable materials such as magnesium alloys, iron alloys, zinc alloys, or poly-L-lactic acid, aiming to overcome the problems of chronic inflammation, late-stage thrombosis, and vascular constriction associated with long-term permanent metal stent placement.

[0003] However, existing non-absorbable vascular stents have the following shortcomings in clinical applications: Although the main body material of conventional vascular stents is somewhat visible under X-rays, its contrast is limited, especially in CT images where it is difficult to clearly show the stent's boundaries and spatial orientation. This makes it difficult for doctors to effectively determine whether the stent has experienced slight displacement, deformation, or shrinkage during postoperative follow-up. Stent displacement or shrinkage can cause serious complications such as restenosis and thrombosis, and early identification and intervention are crucial for improving patient prognosis. In addition, after stent implantation, the position between the stent and the vessel wall is mainly maintained by radial support force, lacking an active anchoring mechanism. Under the influence of vascular pulsation, respiratory movements, or external forces, the stent is prone to slow displacement. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a surface-modified vascular stent that integrates imaging positioning and active anchoring, thereby solving the issues of unclear imaging after surgery, difficulty in determining displacement or deformation, and the lack of an active fixation mechanism leading to long-term displacement risks in current vascular stents.

[0005] This invention provides a surface-modified vascular stent integrating imaging positioning and active anchoring. The vascular stent includes a main stent and an imaging anchoring integrated component disposed on the main stent. The imaging anchoring integrated component includes an imaging ring, an anchoring element, and a linkage stent. The linkage stent is connected between the main stent and the imaging ring; the linkage stent is made of a first shape memory alloy material and is used to expand radially with the main stent after implantation into the blood vessel, and to drive the imaging ring to expand radially synchronously to fit close to the blood vessel wall; The imaging ring has a segmented annular structure, which includes multiple arc segment units distributed circumferentially, and tissue ingrowth gaps are formed between adjacent arc segment units. The tissue ingrowth gaps are configured to induce vascular intima tissue ingrowth to form a biological anchor. The anchoring element includes an anchoring protrusion disposed on the outer surface of the imaging ring. The anchoring protrusion includes a tissue growth lumen and a tissue growth aperture that are interconnected, such that after the imaging ring is radially expanded, the anchoring protrusion forms a mechanical anchor with the blood vessel wall, and allows vascular intima tissue to grow into the tissue growth lumen through the tissue growth aperture to form a deep biological anchor.

[0006] Optionally, the developing ring comprises tantalum material or is made of tantalum material.

[0007] Optionally, the anchor further includes a functional coating applied to the surface of the developing ring, the functional coating including a polyphenol / metal network coating; The anchoring protrusion is disposed on the outer surface of the polyphenol / metal network coating.

[0008] Optionally, the linkage support includes two symmetrically arranged arc-shaped spring arms. The two arc-shaped spring arms are fixed back to back and connected to form a cross linkage structure. The cross linkage structure is configured to restore a preset cross configuration when the main support is radially extended, driving the developing ring to expand radially outward.

[0009] Optionally, the tissue extension port is provided in multiple ways to allow vascular endothelial tissue to enter the tissue extension lumen from multiple directions; and / or, each of the arc segment units is provided with the anchoring protrusion in a one-to-one correspondence.

[0010] Optionally, the vascular stent further includes a defense mechanism, the defense mechanism comprising: A thrombolytic stent is connected to the main stent, and the outer diameter of the thrombolytic stent is smaller than the outer diameter of the main stent, so that a thrombolytic gap is formed between the thrombolytic stent and the vessel wall after the thrombolytic stent and the main stent are radially expanded. A flow-blocking bracket is connected to the thrombus-removing bracket, and the flow-blocking bracket extends along a spiral path; A flow-blocking ring, connected to the flow-blocking bracket, wherein the flow-blocking ring is made of a second shape memory alloy material; The intercepting ring returns to its ring shape when each stent is radially deployed to intercept thrombi in the blood flow. The intercepted thrombi are guided along the spiral path of the intercepting stent to the thrombectomy gap of the thrombectomy stent, where they are ablated by the fibrinolytic system of the vascular wall.

[0011] Optionally, the thrombolytic stent has a tapered shape with a gradually changing outer diameter along the blood flow direction; The thrombus-relieving bracket has an annular groove in the middle, and the annular groove and the thrombus-relieving gap together form a thrombus-relieving cavity.

[0012] Optionally, the flow-blocking bracket extends spirally in diameter from the flow-blocking ring toward the thrombus-removing bracket.

[0013] Optionally, two developing rings are provided; wherein, the first developing ring is provided with the linkage bracket on one side, and the first developing ring is fixed to the end of the main body bracket away from the thrombus-removing bracket by the linkage bracket; the second developing ring is provided with the linkage bracket on opposite sides respectively, one side of the second developing ring is connected to the other end of the main body bracket by the linkage bracket on that side, and the other side of the second developing ring is connected to the thrombus-removing bracket by the linkage bracket on that side.

[0014] Optionally, the surfaces of the main support, the thrombus-removing support, and the flow-blocking support are all coated with a zwitterionic coating.

[0015] Compared with the prior art, this application has the following advantages: The vascular stent provided in this application embodiment achieves visualization and fixation through integrated structural linkage. When the main stent expands, the linked stent deforms synchronously, pushing the visualization ring radially open to approach the vessel wall, thus forming a clear positioning point for the visualization ring in CT images. Simultaneously, the anchoring protrusion in the anchoring member contacts the vessel wall to achieve mechanical anchoring. The vascular intima tissue can then grow into the tissue ingress lumen through the tissue growth port on its surface, forming biological fixation. This gives the main stent both postoperative image visibility and active anti-migration capability, avoiding the long-term displacement risk after vascular stent implantation. Attached Figure Description

[0016] To more clearly illustrate the technical solution of this application, the drawings used in the description of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a diagram illustrating the overall structure of a surface-modified vascular stent that integrates imaging positioning and active anchoring, as provided in an embodiment of this application. Figure 2 This is a three-dimensional structural diagram of the main support provided in an embodiment of this application; Figure 3 This is a three-dimensional structural diagram of a developing anchoring integrated component provided in an embodiment of this application; Figure 4 This is a three-dimensional structural diagram of a thrombus-reducing stent provided in an embodiment of this application; Figure 5 This is a three-dimensional structural diagram of the combination of the flow-blocking bracket and the flow-blocking ring provided in one embodiment of this application; Figure 6 This is a three-dimensional structural diagram of a single arc segment unit and an anchoring element provided in an embodiment of this application; Figure 7 This is a structural disassembly diagram of a single arc segment unit and anchoring element combined according to an embodiment of this application; Figure 8 This is a cross-sectional view of the anchoring protrusion provided in one embodiment of this application, cut along the center line.

[0018] Explanation of reference numerals in the attached figures: 1. Main support; 2. Development and anchoring integrated component; 21. Development ring; 22. Linkage support; 23. Anchoring component; 231. Functional coating; 232. Anchoring protrusion; 233. Tissue access hole; 3. Defense mechanism; 31. Thrombus dissipation support; 32. Flow interception support; 33. Flow interception ring. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] It should be noted that vascular stents, as interventional medical devices, are inserted into narrowed or occluded blood vessel segments via a delivery system after percutaneous puncture. They restore blood flow by expanding the vessel wall through radial expansion. However, in practical use, vascular stents still have the following shortcomings and inherent limitations in postoperative imaging monitoring and long-term expansion: First, the lack of linkage between the radiopaque markers and the stent body leads to insufficient accuracy in postoperative imaging localization. Existing vascular stents typically have radiopaque markers at their ends, usually fixed to local or continuous radiopaque points on the stent via fixation or welding. During radial expansion, the stretching and rearrangement of the stent wires cause unpredictable changes in the spatial position of the markers, resulting in uncertainty in the relative position between the markers and the vessel wall during imaging. Furthermore, local radiopaque points only indicate the approximate location of the stent, making it difficult to accurately determine the stent's boundary contours and spatial orientation. While continuous radiopaque points offer better imaging continuity, their high overall rigidity leads to poor compliance with the vessel wall when the stent bends or pulsates, easily causing local stress concentration. Moreover, there is a lack of biological integration between the markers and the vessel wall. Finally, during CT follow-up, the imaging boundaries of the markers in the CT image are blurred, resulting in limited localization contrast. Therefore, it is difficult for the operator to accurately determine whether the stent has shifted, contracted, or deformed.

[0021] Second, the structural design of the contrast markers does not take into account the anchoring function, resulting in a single function. The main, or even sole, function of the markers on existing vascular stents is to provide imaging contrast. In the long run, relying solely on the radial support force of the vascular stent to maintain the position of the entire stent and the markers carries a risk of slow displacement under periodic loads such as vascular pulsation and respiratory movements. To address the stent displacement problem, additional anchoring components are usually designed and placed separately from the contrast markers at different locations on the stent. The positions and structural choices of these two components are often arbitrary, and in some designs, the presence of the anchoring components can even interfere with the imaging quality of the contrast markers (e.g., the anchoring components produce artifacts in CT images).

[0022] Third, traditional anchoring components struggle to achieve reliable long-term fixation. While the mechanical interlocking of anchoring components improves the frictional anchoring force between the stent and the vessel wall to some extent, such designs only achieve superficial mechanical interlocking with the vessel wall through their surface contours. The bond between the tissue and the anchoring component is limited to surface contact, lacking three-dimensional interlocking, resulting in insufficient anchoring strength and durability. Once the radial force between the stent and the vessel wall weakens due to vascular dilation, the superficial mechanical anchoring fails, making it difficult to effectively address the long-term stent displacement problem after long-term implantation.

[0023] Fourth, the risks of thrombosis and restenosis caused by protein adsorption remain unresolved. When existing vascular stents come into contact with blood, non-specific protein adsorption inevitably occurs on the metal surface and some coating materials. The adsorbed protein layer subsequently activates platelet and coagulation cascade reactions, leading to thrombosis. Simultaneously, protein adsorption also promotes the migration and proliferation of smooth muscle cells into the intima, a significant contributing factor to in-stent restenosis. Although anti-proliferative drugs can be coated onto the surface of existing stents to inhibit smooth muscle proliferation, these drug coatings suffer from limited release periods and rebound effects after drug depletion.

[0024] Fifth, once an in-stent thrombosis forms on a current vascular stent, the thrombus can migrate distally with the blood flow, causing distal vessel embolism. After stent implantation, because the design focuses solely on the stent's radial support and luminal patency, once a thrombus forms within or near the stent, it is easily detached from the stent wall under the shear force of the blood flow and travels to distal vessels. Therefore, current vascular stents, when faced with the clinical reality of post-operative in-stent thrombosis, cannot prevent thrombus formation, intercept the distal migration of existing thrombi, or perform on-site ablation of intercepted thrombi. This has become a serious problem restricting the long-term safety of vascular stents.

[0025] Therefore, there is an urgent need for a comprehensive vascular stent with high-contrast imaging capabilities, the ability to monitor stent position and status, active anchoring to prevent displacement, and the ability to intercept and ablate thrombi on-site. This stent is intended to address the problems of unclear CT imaging, difficulty in determining displacement or deformation, and the lack of active fixation mechanisms that lead to long-term displacement risks associated with existing non-absorbable vascular stents.

[0026] In order to overcome or at least partially solve the above problems, refer to Figure 1 , Figure 2 , Figure 3 and Figure 7 As shown, Figure 1 This diagram illustrates the overall structural composition of a surface-modified vascular stent that integrates imaging localization and active anchoring according to one or more embodiments of this application. Figure 2 The three-dimensional structure of the main support 1 is shown separately. Figure 3 The three-dimensional structure of the developing anchoring assembly 2 is shown separately. Figure 7 This is a structural disassembly diagram of a single arc segment unit and anchor 23 combined. (See diagram below.) Figure 1 , Figure 2 and Figure 3 As shown, and in conjunction with reference Figure 7This invention provides a surface-modified vascular stent integrating imaging positioning and active anchoring. The vascular stent includes a main stent 1 and an imaging anchoring integrated component 2 disposed on the main stent 1. The imaging anchoring integrated component 2 includes an imaging ring 21, an anchoring component 23, and a linkage stent 22. The linkage stent 22 connects the main stent 1 and the imaging ring 21. The linkage stent 22 is made of a first shape memory alloy material and is used to radially expand along with the main stent 1 after implantation into the blood vessel, and to synchronously drive the imaging ring 21 to radially expand to approach the blood vessel wall. The imaging ring 21 has a segmented annular structure. The segmented ring structure includes multiple arc segment units distributed circumferentially, and tissue ingrowth gaps are formed between adjacent arc segment units. The tissue ingrowth gaps are configured to induce vascular intima tissue ingrowth to form a biological anchor. The anchoring element 23 includes an anchoring protrusion 232 disposed on the outer surface of the imaging ring 21. The anchoring protrusion 232 includes interconnected tissue ingrowth cavities and tissue ingrowth holes 233, such that after the imaging ring 21 is radially expanded, the anchoring protrusion 232 forms a mechanical anchor with the vascular wall, and allows vascular intima tissue to grow into the tissue ingrowth cavity through the tissue ingrowth holes 233 to form a deep biological anchor.

[0027] In this embodiment, the main stent 1 is a support structure for implantation into the lumen of a human blood vessel to maintain vascular patency. The main stent 1 can be a traditional vascular stent, such as a non-absorbable vascular stent or a bioresorbable vascular stent. This embodiment preferably uses a bioresorbable vascular stent, which is made of shape memory alloy material using three-dimensional braiding technology. The main stent 1, along with the newly added thrombolytic stent 31 and shunt stent 32, all adopt a braided mesh structure. The mesh size of the braided mesh structure is configured to allow red blood cells, white blood cells, and platelets—normal blood cells—to pass freely without obstruction. The braided mesh structure endows each stent with good shape memory characteristics, flexibility, and conformability, allowing it to be compressed and inserted into the blood vessel by the delivery system, and to radially expand from a contracted configuration back to a preset configuration to conform to the blood vessel wall after release. The structural principles of the radial expansion and contraction and the delivery system are relatively mature and will not be elaborated further.

[0028] The improvement in this embodiment lies in the developing anchoring integration 2 disposed on the main support 1. The developing anchoring integration 2 includes a developing ring 21, an anchoring element 23, and a linkage bracket 22. These three components are structurally integrated and functionally coordinated, forming an integrated structural unit that combines imaging development positioning and active anchoring fixation. Specifically, the developing anchoring integration 2 is disposed at at least one end of the main support 1. For example, the developing anchoring integration 2 can be disposed at the proximal end, distal end, or both ends of the main support 1. In some embodiments, the developing anchoring integration 2 can be disposed in other areas of the main support 1 besides the end region.

[0029] The linkage support 22 is connected between the main support 1 and the developing ring 21, and is made of a first shape memory alloy material. This allows the linkage support 22 to automatically recover from a contracted configuration to a preset expanded configuration when the main support 1 expands radially, and to transmit the radial expansion force to the developing ring 21 connected to it. The first shape memory alloy material can be a nickel-titanium shape memory alloy, a copper-based shape memory alloy, an iron-based shape memory alloy, or other shape memory alloy materials with superelasticity and shape recovery capabilities.

[0030] When the vascular stent is in a compressed delivery state, the linkage stent 22 is also in a contracted configuration, bringing the imaging ring 21 to the outer periphery of the end of the main stent 1. This ensures that the radial envelope dimension of the imaging anchoring assembly 2 matches the outer diameter of the main stent 1, and the stent is placed into the target blood vessel position along with the main stent 1 via the delivery system. When the main stent 1 is released and expands radially at the target position, the linkage stent 22, being connected to the main stent 1, expands along with the main stent 1. Simultaneously, the shape memory recovery force of the first shape memory alloy material drives the linkage stent 22 to actively expand, causing it to return from the contracted configuration to the preset expanded configuration. This, in turn, drives the imaging ring 21 connected to it to expand radially outward, bringing the imaging ring 21 close to the blood vessel wall. The imaging ring 21 serves as an imaging marker, generating a high-contrast imaging signal in CT images to mark the spatial position of the end of the main stent 1. Subsequently, the anchoring element 23 on the imaging ring 21 comes into pre-contact with the blood vessel wall during the process of the imaging ring 21 adhering to the blood vessel wall, achieving preliminary mechanical anchoring; and during the subsequent recovery period, it allows the intima tissue to grow in, forming deep biological anchoring.

[0031] In some embodiments, the developing ring 21 may be made of a high-density developing material, including but not limited to platinum, platinum-iridium alloy, tantalum, tungsten, gold, iridium, rhenium, platinum-tungsten alloy, cobalt-chromium developing alloy, or other developing materials that are non-transparent.

[0032] It should be noted that the outer diameter of the preset unfolded configuration of the linkage stent 22 is nearly equal to the outer diameter of the unfolded configuration of the main stent 1. When the main stent 1 is fully expanded, the linkage stent 22 is flush with the mesh surface of the main stent 1. At the same time, the outer diameter of the imaging ring 21 that unfolds with the linkage stent 22 is also nearly equal to the inner diameter of the target blood vessel, so that the imaging ring 21 can closely fit the blood vessel wall, and the micron-sized anchoring protrusions 232 on the imaging ring 21 can closely fit the blood vessel wall without causing excessive pressure.

[0033] Preferably, the imaging ring 21 has a segmented annular structure or a discontinuous arc-shaped structure, which includes multiple arc-shaped units spaced circumferentially, forming tissue ingrowth gaps between adjacent arc-shaped units. The number of arc-shaped units can be selected according to the diameter or woven mesh shape of the main support 1, or the imaging resolution required for the imaging ring 21. In an exemplary embodiment, the number of arc-shaped units is 2, 3, 4, 6, 8, or more. Each arc-shaped unit can have the same length or be designed with different lengths. In one embodiment, the gap width of the tissue ingrowth gap is determined by factors such as the number and shape of the arc-shaped units. Therefore, multiple arc-shaped units divide the continuous imaging ring 21 into multiple independent segments. The segmented arc-shaped structure reduces the overall stiffness of the imaging ring 21, making its flexibility match the woven mesh structure of the main support 1, allowing the imaging ring 21 to smoothly compress and expand with the main support 1, improving delivery flexibility and vascular compliance. Then, the tissue ingrowth gaps between adjacent arc segments can induce intimal tissue ingrowth to form a biological anchor, achieving functional integration of imaging and anchoring functions on the same imaging ring 21, thus enhancing the long-term stability of the stent. In addition, the segmented arc structure reduces CT artifacts caused by continuous metal structures, improves image quality, and reduces the amount of imaging material used and manufacturing costs.

[0034] In some embodiments, the arc segment units may be arc-shaped, wavy, zigzag-shaped, or other non-continuous annular structures. The virtual contour formed by connecting multiple arc segment units is circular, thus allowing it to expand radially and circumferentially close to the vessel wall under the action of the linkage stent 22. At this time, each arc segment unit forms an annular imaging contour distributed around the stent boundary under CT or X-ray imaging, enabling the surgeon to directly identify the edge and spatial orientation of the main stent 1 through the imaging contour, thereby improving the ability to identify stent displacement, local collapse, deformation, and structural integrity during postoperative image follow-up.

[0035] More preferably, the imaging ring 21 is an imaging tantalum ring made of tantalum material or a composite of tantalum material and other metal materials. In one embodiment, the imaging tantalum ring is made of medical-grade pure tantalum. In another embodiment, the imaging tantalum ring is made of tantalum-based alloy. CT imaging is based on the attenuation differences of X-rays when penetrating tissue. Tantalum has a high atomic number and high density, both of which give medical-grade tantalum extremely strong X-ray attenuation capabilities. When X-rays pass through the imaging tantalum ring in the area where the main support 1 is located, tantalum atoms significantly absorb and scatter the X-rays through the photoelectric effect and Compton effect, making its linear attenuation coefficient much higher than that of blood vessels, blood, and surrounding soft tissue. This results in the imaging tantalum ring appearing as a high-brightness, high-contrast imaging point in the CT reconstructed image, thus achieving a high-contrast imaging effect in CT imaging for accurately determining the spatial position of the main support 1.

[0036] In this embodiment, the imaging ring 21 also serves as the carrier of the anchoring element 23. The imaging ring 21 provides structural support and anchoring position for the anchoring element 23 through a stable adherence to the vessel wall. The anchoring element 23 is disposed on the outer surface of the imaging ring 21 facing the vessel wall. The anchoring element 23 can form initial mechanical anchoring in the early stage of the main support 1 release, and form long-term deep biological anchoring together with the tissue in the later stage. In this embodiment, the anchoring element 23 adopts an anchoring protrusion 232, which protrudes outward from the outer surface of the imaging ring 21, and the protrusion height is on the micrometer level to form micro-protrusions. The shape of the anchoring protrusion 232 can be hemispherical, dome-shaped, columnar, truncated cone-shaped, wedge-shaped, frustum-shaped, hook-shaped, barbed, mushroom-shaped, or other shapes with local protruding structures. Preferably, the anchoring protrusion 232 adopts a smooth transition structure to reduce the risk of damage to the vessel wall. When the imaging ring 21 expands radially and adheres tightly to the vessel wall, the anchoring protrusion 232 contacts the vessel wall first.

[0037] Specifically, the anchoring protrusion 232 is a hollow shell structure. Within this hollow shell structure, a tissue elongation cavity is formed inside the anchoring shell. In one embodiment, the anchoring shell is a semi-closed shell, with its opening facing the outer surface of the imaging ring 21 and sealed to the outer surface of the imaging ring 21 (or the outer surface of the functional coating 231 mentioned later), allowing the tissue elongation cavity to communicate with the external environment only through the tissue elongation hole 233 on the shell wall of the anchoring shell. In one embodiment, the anchoring shell is prepared using a template method, integrating the anchoring shell and the functional coating 231 into one unit. In some embodiments, the shape of the tissue elongation cavity can match the shape of the anchoring protrusion 232. The wall thickness of the anchoring shell can then be designed according to the diameter of the target blood vessel, the expected tissue proliferation rate, and the anchoring requirements; for example, the volume of the tissue elongation cavity is 20%–90% of the overall volume of the anchoring protrusion 232.

[0038] Tissue elongation holes 233 are formed in the shell wall of the anchoring shell to connect the tissue elongation cavity with the external environment. In one embodiment, the tissue elongation holes 233 can be circular holes, elliptical holes, elongated holes, cross holes, honeycomb holes, mesh holes, or other through-hole structures. The diameter of the tissue elongation holes 233 is appropriate, allowing vascular endothelial tissue to pass through within a suitable diameter range, without weakening the mechanical strength of the anchoring shell due to excessively large diameters. In a preferred embodiment, multiple tissue elongation holes 233 are provided and distributed on the shell wall of the anchoring shell, allowing vascular endothelial tissue to enter the tissue elongation cavity simultaneously from multiple directions.

[0039] Therefore, when the imaging ring 21 adheres to the vessel wall, the anchoring protrusion 232 first contacts the vessel wall to achieve initial mechanical anchoring as the imaging ring 21 expands with the main scaffold 1. Subsequently, the vascular endothelial tissue gradually migrates to the surface of the anchoring shell during the reparative proliferation process. Since the surface of the anchoring shell is provided with tissue elongation holes 233, the vascular endothelial tissue can enter the interior of the tissue elongation lumen through the tissue elongation holes 233, and grow, proliferate, and fill in the lumen in multiple directions, eventually forming a three-dimensional interlocking structure similar to an anchor bolt. When the tissue elongation lumen is filled with vascular endothelial tissue, deep biological anchoring is achieved between the anchoring protrusion 232 and the vessel wall, thereby enhancing the bonding strength between the main scaffold 1 and the vessel wall and effectively preventing long-term displacement.

[0040] In combination with the above embodiments, the tissue ingrowth gap and tissue ingrowth cavity work together to form a two-level biological anchoring system.

[0041] In summary, by integrating the imaging ring 21, the anchoring element 23, and the linkage stent 22 into the imaging anchoring integrated element 2, the imaging positioning function and the active anchoring function are organically integrated and coordinated within the same structural unit. This not only improves the visualization and recognition capabilities under CT images, but also enables active anchoring and long-term stable fixation after stent implantation, thereby effectively solving the technical problems in the existing technology, such as unclear imaging, difficulty in monitoring postoperative status, and high risk of long-term displacement.

[0042] The linkage stent 22 automatically returns to its preset deployment configuration during the expansion of the main stent 1 without any additional operating steps or external drive, thus achieving automatic linkage of the deployment of the imaging ring 21 and ensuring the positional certainty of the imaging ring 21 after stent expansion. After the imaging ring 21 is driven to approach the vessel wall, it improves the contrast and boundary clarity of the imaging markers in the CT image.

[0043] The discontinuous, segmented arc-shaped structure divides the imaging ring 21 into multiple arc-shaped units, effectively reducing the overall bending stiffness of the imaging ring 21 and significantly improving its flexibility and adaptability. This allows it to compress and expand smoothly in sync with the main support 1, avoiding bending difficulties or stress concentration in the support due to excessive local stiffness of the imaging ring 21. Furthermore, the segmented arc-shaped structure reduces CT artifacts caused by continuous metal structures, improving image quality and reducing the amount of imaging material used and manufacturing costs.

[0044] The tissue ingrowth gaps between the arc-shaped units provide an open growth space for the vascular endothelial tissue. The vascular endothelial tissue can grow into and encapsulate the arc-shaped units through these gaps, directly achieving the first-level biological anchoring of the imaging ring 21 itself. The hollow anchoring protrusion 232 provides a tissue ingrowth cavity for the vascular endothelial tissue. The vascular endothelial tissue can slowly fill the tissue ingrowth cavity through the tissue ingrowth aperture 233, achieving the second-level biological anchoring of the imaging ring 21 through the anchoring protrusion 232. Furthermore, the hollow anchoring protrusion 232 makes initial contact with the vessel wall as the imaging ring 21 radially expands, forming a preliminary mechanical anchoring between the anchoring protrusion 232 and the vessel wall. This combination of mechanical anchoring and multi-level biological anchoring significantly improves the long-term positional stability of the stent after implantation, reducing the risk of stent migration, slippage, rotational displacement, and local collapse.

[0045] like Figure 6 and Figure 7 The diagrams show the three-dimensional structure and disassembled structure of the individual arc segment unit and anchor 23 combined. Optionally, the anchor 23 further includes a functional coating 231 coated on the surface of the imaging ring 21. The functional coating 231 includes a polyphenol / metal network coating; wherein, the anchoring protrusion 232 is disposed on the outer surface of the polyphenol / metal network coating. In this embodiment, the functional coating 231 is first formed on the surface of the imaging ring 21, and then the anchoring protrusion 232 is disposed on the side of the functional coating 231 facing the blood vessel wall. The anchoring protrusion 232 can be prepared on the functional coating 231 using a template method. The functional coating 231 is a polyphenol / metal network coating, which constructs a stable hydrophilic interface on the surface of the main scaffold 1 through the coordination of phenolic hydroxyl groups with metal ions and oxidative polymerization reaction. On the one hand, this polyphenol / metal network coating possesses glutathione peroxidase-like catalytic activity, enabling it to catalyze the continuous release of physiological levels of nitric oxide from endogenous nitric oxide donors in the blood, effectively inhibiting platelet adhesion and activation, prolonging clotting time, and achieving excellent in-situ anticoagulant properties. On the other hand, this polyphenol / metal network coating can selectively promote vascular endothelial cell adhesion and proliferation while inhibiting excessive smooth muscle cell proliferation, accelerating the process of vascular intimal repair and re-endothelialization, thereby reducing the risk of in-stent restenosis. Furthermore, the residual phenolic hydroxyl groups on the surface of the polyphenol / metal network coating endow it with good antioxidant and anti-inflammatory properties, effectively inhibiting inflammatory responses, and exhibiting good cell compatibility, making it suitable for surface functionalization modification of cardiovascular implants.

[0046] In some embodiments, the surface roughness of the polyphenol / metal network coating is controlled between 100 nm and 500 nm. Submicron-level roughness avoids the risk of platelet activation and thrombosis induced by surface morphology, helps reduce specular reflection and beam hardening effects of X-rays at the metal-tissue interface, thereby suppressing artifact generation.

[0047] Therefore, the anchoring element 23 works synergistically with the anchoring protrusion 232 through the polyphenol / metal network coating. The polyphenol / metal network coating has anticoagulant, endothelialization-promoting, smooth muscle proliferation-inhibiting, anti-inflammatory, and antioxidant effects, while its submicron-level roughness can reduce CT artifacts. The anchoring protrusion 232 realizes the positioning of the main stent 1 in CT images and prevents long-term displacement of the main stent 1 through a dual fixation method. This effectively solves the problems of limited contrast in CT images leading to unclear imaging, difficulty in effectively judging whether the stent has displaced or deformed after surgery, and the risk of long-term displacement due to the lack of an active fixation mechanism.

[0048] Optionally, the linkage bracket 22 includes two symmetrically arranged arc-shaped spring arms. The two arc-shaped spring arms are fixed back to back and connected to form a cross-linkage structure. The cross-linkage structure is configured to return from a contracted configuration to a preset cross configuration when the main bracket 1 is radially expanded, driving the developing ring 21 to expand radially outward. In this embodiment, the two arc-shaped spring arms are integrally formed from a first shape memory alloy material or separately processed and then connected to form an X-shaped cross-linkage bracket 22. In one embodiment, the two arc-shaped spring arms are both identical C-shaped arc segments. The arc bases of the two C-shaped arc segments are fixed back to back, forming an X-shaped cross-linkage bracket. The two ends of the opening of one C-shaped arc segment are connected to the main bracket 1, and the two ends of the opening of the other C-shaped arc segment are connected to the developing ring 21. In another embodiment, the two arc-shaped spring arms are two inclined, extending arc-shaped arms that cross and connect at the middle, forming a roughly X-shaped cross-linking bracket. The two ends of one arc-shaped arm connect to two opposite corners of the main support 1 and the developing ring 21, respectively, and the two ends of the other arc-shaped arm also connect to two opposite corners of the main support 1 and the developing ring 21, respectively. In one embodiment, the two arc-shaped spring arms are fixedly connected at the connection point by welding or integral machining.

[0049] In the unexpanded state, the two arc-shaped elastic arms converge and fit together along the axial and radial directions of the main support 1, causing the linkage stent 22 to be in a contracted configuration. This compresses the imaging ring 21 to both ends of the main support 1, allowing the imaging ring 21 and the main support 1 to be placed into the target blood vessel location via the delivery system. When the main support 1 is released and expands, the linkage stent 22 deforms along with the expansion of the main support 1 and returns to its preset cross configuration, such as an X-shaped configuration, pushing the imaging ring to expand radially synchronously, bringing it close to the blood vessel wall. The symmetrically arranged two arc-shaped elastic arms ensure the smoothness and stability of the expansion movement of the imaging ring 21 driven by the linkage stent 22 during the movement process, preventing the imaging ring 21 from being locally deviated or tilted. In some embodiments, the cross linkage structure can also use two or more arc-shaped elastic arms to form a double X-shaped, star-shaped, or mesh-like linkage structure. In some other embodiments, the two arc-shaped spring arms can also be arranged asymmetrically. By designing the relative position of the intersection point on the two arc-shaped spring arms (i.e., the ratio of the arm length from the intersection point to both ends), the displacement amplification ratio can be flexibly adjusted so that the developing ring 21 can obtain an outward stroke that is greater than or less than the expansion amount of the main support 1.

[0050] like Figure 8 As shown, Figure 8 This is a cross-sectional view of the anchoring protrusion 232 after being cut along its centerline. Optionally, multiple tissue elongation holes 233 are provided to allow vascular endothelial tissue to enter the tissue elongation lumen from multiple directions; and / or, each arc segment unit is provided with a linkage support 22 so that each arc segment unit extends outward uniformly and synchronously as the main support 1 expands radially. In one embodiment, a tissue elongation hole 233 is provided on the top surface of the anchoring shell, and multiple tissue elongation holes 233 are provided on the sides. The tissue elongation hole 233 on the top surface allows vascular endothelial tissue growing perpendicular to the vessel wall to enter the tissue elongation lumen, while the multiple tissue elongation holes 233 on the sides allow vascular endothelial tissue growing circumferentially along the anchoring shell to enter the tissue elongation lumen from multiple lateral directions. The vascular endothelial tissue entering from different directions interweaves and grows within the tissue elongation lumen to form a three-dimensional mesh anchoring structure, which not only accelerates the filling rate of the tissue elongation lumen and shortens the formation time of biological anchoring, but also results in higher tensile strength and shear strength. Since the imaging ring 21 is a segmented ring structure, an independent linkage stent 22 is set on each arc segment unit, so that each arc segment unit obtains direct expansion driving force from the linkage stent 22, ensuring that all arc segment units expand outwards evenly and synchronously and adhere tightly to the blood vessel wall.

[0051] In some embodiments, all arc segment units are provided with anchoring protrusions 232. In some embodiments, only some arc segment units may be provided with anchoring protrusions 232.

[0052] In summary, one or more embodiments of the present invention achieve imaging and fixation through structural linkage. When the main stent 1 expands, the linkage stent 22 restores its X-shape and pushes the imaging tantalum ring radially open to approach the blood vessel wall, so that the high atomic number tantalum ring forms a clear positioning point in the CT image. At the same time, the anchoring protrusion 232 in the anchoring member 23 contacts the blood vessel wall to achieve mechanical anchoring. The vascular intima tissue can then grow into the tissue ingress lumen through the tissue elongation hole 233 on its surface, forming biological fixation. This gives the main stent 1 both postoperative image visibility and active anti-displacement capability, effectively solving the problems of unclear CT imaging and lack of fixation mechanism in traditional main stent 1.

[0053] Combination Figure 1 And see Figure 4 and Figure 5 , Figure 4 This is a three-dimensional structural diagram of the thrombus-reducing support 31; Figure 5 This is a three-dimensional structural diagram of the combined flow-blocking stent 32 and flow-blocking ring 33. This embodiment illustrates another type of vascular stent, which includes a main stent 1, a thrombectomy stent 31, and a flow-blocking stent 32 connected sequentially. The main stent 1 can be the structure provided in one or more of the embodiments above. The thrombectomy stent 31 is connected to the main stent 1 and is located upstream of the main stent 1 along the blood flow direction, and is connected to the end of the main stent 1 via a linkage stent 22 and a contrast ring 21. The flow-blocking stent 32 is located upstream of the thrombectomy stent 31 along the blood flow direction and extends along a spiral path. The flow-blocking ring 33 is made of a second shape memory alloy material, such as a nickel-titanium shape memory alloy, which allows it to spontaneously recover to a preset ring configuration in vivo. In one embodiment, the flow-blocking ring 33 is a closed ring structure in its unfolded state, and its ring body is formed by bending a second shape memory alloy wire, with the inner diameter of the ring body configured to be smaller than the inner diameter of the main stent 1.

[0054] When the main stent 1, the thrombectomy stent 31, and the thrombectomy stent 32 expand synchronously, the thrombectomy ring 33 returns to its annular configuration. This annular configuration allows normal blood components such as red blood cells, white blood cells, and platelets to pass freely, but physically obstructs larger thrombi in the blood flow. The obstructed thrombi, guided by the spirally distributed thrombectomy stent 32, move along the spiral path in the direction of blood flow to the area where the thrombectomy stent 31 is located. Since the diameter of the thrombectomy stent 31 is smaller than that of the main stent 1, when it expands synchronously at the target vessel location, an annular gap is formed between its outer peripheral surface and the vessel wall. This annular gap serves as a thrombectomy gap, which can accommodate the thrombi guided there and direct them towards the vicinity of the vessel wall for ablation by the fibrinolytic system. Therefore, the defense mechanism 3 can be used to intercept and divert thrombi, preventing them from flowing to distant sites and causing embolism. This enables the vascular stent as a whole to actively handle thrombi that have already formed, avoiding the need for secondary interventional procedures required for thrombectomy stents. It effectively solves the problem that the existing main stent 1 is unable to effectively intercept and ablate thrombi that have already formed in the blood flow, and cannot prevent thrombi from falling off and causing distal vascular embolism.

[0055] In conjunction with the above embodiments, the first shape memory alloy material and the second shape memory alloy material can be the same or different. For example, both the first and second shape memory alloy materials are made of the same material as the main support structure, namely, a nickel-titanium alloy.

[0056] In a preferred embodiment, the flow-blocking stent 32 adopts an expanding-diameter conical spiral configuration along the blood flow direction. Specifically, each alloy wire of the flow-blocking stent 32 is evenly spaced on the ring body of the flow-blocking ring 33, serving as the starting point of the spiral. Each wire spirals and extends along the conical surface towards the thrombolytic stent 31 with a preset spiral angle. The spiral radius of each alloy wire gradually increases from the flow-blocking ring 33 towards the thrombolytic stent 31, making the flow-blocking stent 32 present an overall trumpet-shaped conical spiral shape that gradually widens from upstream to downstream along the blood flow direction. In one embodiment, the adjacent alloy wires of the flow-blocking stent 32 maintain a substantially equal spiral spacing, and the spiral angle and number of spiral turns of each alloy wire are equal, with each alloy wire extending parallel to each other. The spiral extension endpoint of each alloy wire is fixedly connected to the edge of the braided mesh of the thrombolytic stent 31. In an optional embodiment, the ends of the alloy wires of the flow-blocking stent 32 are fixed to the edge of the braided mesh of the thrombolytic stent 31 by laser welding, and are also fixed to the ring body of the flow-blocking ring 33 by laser welding.

[0057] For example, the thrombectomy stent 32 includes seven alloy wires, each extending independently and parallel to each other without crossing, forming a trumpet-shaped conical spiral. The narrow end of the trumpet-shaped conical spiral is connected to the thrombectomy ring 33, and the flared end is connected to the edge of the braided mesh of the thrombectomy stent 31. The trumpet-shaped conical spiral shape creates a smoothly transitioning conical flow channel between the thrombectomy ring 33 and the thrombectomy stent 31, producing a continuous spiral guiding effect on blood flow and achieving efficient directional delivery of thrombi in the blood from the interception area to the ablation area.

[0058] In a preferred embodiment, the thrombolytic stent 31 along the blood flow direction adopts a tapered gradient configuration. Specifically, the thrombolytic stent 31 is continuously formed from a braided mesh into a cage-like body that tapers initially, expands in the middle, and tapers at the end, along the direction close to the shunt stent 32. For example, taking the blood flow direction as an example, the alloy wire of the thrombolytic stent 31 extends upstream from its downstream end, which connects to the edge of the braided mesh of the main stent 1, with a gradually decreasing braiding diameter. The outer diameter of the initial section exhibits an approximately linear tapering transition along the axial direction. As it continues to extend upstream, the braiding diameter gradually increases, and the outer diameter of the middle section exhibits an approximately linear increasing transition along the axial direction. Continuing upstream to connect with the shunt stent 32, the braiding diameter gradually decreases, and the outer diameter of the final section exhibits an approximately linear tapering transition along the axial direction. Since the radial width of the thrombolytic gap is determined by the distance between the surface of the thrombolytic stent 31 and the vessel wall, and the outer diameter of the thrombolytic stent 31 has a tapered gradient, the radial width of the thrombolytic gap also transitions taperedly from the upstream end to the downstream end, forming a wedge-shaped annular thrombolytic gap that is narrower upstream and wider downstream.

[0059] In one exemplary embodiment, the outer diameter of the thrombolytic stent 31, from its downstream end connected to the main stent 1 to its upstream end where the thrombolytic stent 32 is located, can gradually decrease and then gradually increase, forming an overall waist-shaped shape and creating a waist-shaped thrombolytic gap with the blood vessel wall. In another exemplary embodiment, the outer diameter of the thrombolytic stent 31, from its downstream end connected to the main stent 1 to its upstream end where the thrombolytic stent 32 is located, can continuously gradually decrease or continuously gradually increase, forming an overall frustum-shaped shape and creating a frustum-shaped thrombolytic gap with the blood vessel wall.

[0060] Therefore, the thrombolytic stent 31 is designed with a tapered, gradually changing configuration. Simultaneously, the stent 31 forms a gradually changing thrombolytic gap with the vessel wall at different axial positions. Thrombi guided by the thrombectomy stent 32 enter the thrombolytic gap along a spiral path. Larger thrombi can be accommodated and retained in the wider gap area, while smaller thrombi can be intercepted in the narrower gap area. This allows thrombi of different sizes to be effectively captured at different axial positions of the thrombolytic stent 31, improving thrombus capture efficiency and space utilization. Simultaneously, the tapered exterior of the thrombolytic stent 31 also provides a conical guiding effect on blood flow, enabling directional delivery of thrombi in the blood to the thrombolytic gap.

[0061] As a preferred design in this embodiment, the annular groove is formed on the outer surface of the middle part of the thrombolytic stent 31, and its cross-section can be U-shaped or V-shaped. The annular groove and the thrombolytic gap together form a thrombolytic cavity, that is, the radial depth of the thrombolytic cavity is the sum of the radial width of the thrombolytic gap and the groove depth of the annular groove. Therefore, the thrombolytic cavity formed by the annular groove and the thrombolytic gap of the thrombolytic stent 31 increases the thrombus-accommodating volume and improves the long-term interception and guidance function.

[0062] In another embodiment, two developing rings 21 are provided; wherein, a linkage bracket 22 is provided on one side of the first developing ring 21, and the first developing ring 21 is fixed to the end of the main body bracket 1 away from the thrombus-removing bracket 31 by the linkage bracket 22; linkage brackets 22 are provided on opposite sides of the second developing ring 21, one side of the second developing ring 21 is connected to the other end of the main body bracket 1 by the linkage bracket 22 on that side, and the other side of the second developing ring 21 is connected to the thrombus-removing bracket 31 by the linkage bracket 22 on that side.

[0063] In this embodiment, both the main support 1 and the thrombus-relieving support 31 adopt a woven mesh structure, which is woven from multiple nickel-titanium alloy wires in a cross-interlacing manner, forming rhomboid or approximately rhomboid mesh holes at the intersection points of the woven wires. The ends of the woven wires of the main support 1 are open intersections at the upstream and downstream edges, respectively, while the ends of the woven wires of the thrombus-relieving support 31 are open intersections at the downstream edge, resembling a transverse V-shape, with the V-shaped opening facing the developing ring 21. Optionally, the ends of the woven wires of the thrombus-relieving support 31 are closed intersections at the upstream edge, resembling a transverse V-shape, with the closed V-shaped end facing the intercepting support 32. Therefore, the two intersections of the main support 1 are connected to a preset cross configuration formed by the two arc-shaped elastic arms of the linkage support 22. In this embodiment, the developing rings 21 are a first developing ring 21 and a second developing ring 21. The first developing ring 21 is connected to the downstream end of the main support 1 via the linkage support 22, therefore, a linkage support 22 can be provided on the side of the first developing ring 21 closest to the main support 1. The second developing ring 21 is connected to the upstream end of the main support 1 and the downstream end of the thrombus-removing support 31. Therefore, linkage supports 22 are provided on both sides of the second developing ring 21, thereby connecting the thrombus-removing support 31 and the main support 1 together through the second developing ring 21 and its linkage supports 22.

[0064] Thus, the two imaging rings 21 are respectively set at both ends of the main support 1 to form double-end marks. The surgeon can simultaneously observe the spatial position of both ends of the support system through CT images and accurately determine the overall posture of the support system. The second imaging ring 21 serves as the connection node between the main support 1 and the thrombectomy support 31. It is organically connected to the two through the linkage support 22 on both sides to form an integrated support system, realizing synchronous radial expansion and contraction between the supports during delivery and deployment.

[0065] In another embodiment, the surfaces of the main stent 1, the thrombolytic stent 31, and the thrombectomy stent 32 are all coated with a zwitterionic coating. In some embodiments, the zwitterionic coating is composed of a polymer containing positively and negatively charged groups. The zwitterionic coating has a biomimetic cell membrane structure, forming a dense hydration layer on its surface through strong hydration. This hydration layer acts as a physical barrier to inhibit protein adsorption, thereby prolonging clotting time, promoting increased endothelial cell activity, and reducing the expression levels of inflammatory factors. In this embodiment, the thrombolytic stent 31 and the thrombectomy stent 32 are in contact with the thrombus throughout the entire process of thrombus interception, guidance, and retention. By coating the surfaces of the thrombolytic stent 31 and the thrombectomy stent 32 with a zwitterionic coating, the risk of secondary fixation of the thrombus on the stent surface can also be reduced, which is beneficial for the complete ablation of the thrombus under the action of the fibrinolytic system.

[0066] The specific embodiments of the present invention will be fully described below in conjunction with the above embodiments and accompanying drawings.

[0067] Example 1: A surface-modified vascular stent integrating imaging localization and active anchoring comprises a main stent 1, a thrombolytic stent 31, and a flow-blocking stent 32, all coated with zwitterionic coatings. Each stent is three-dimensionally woven. In its deployed state, the main stent 1 is a hollow tubular structure, the thrombolytic stent 31 has a tapered, gradually tapered configuration, and the flow-blocking stent 32 has an expanded-diameter tapered spiral configuration. The diameters of the main stent 1, thrombolytic stent 31, and flow-blocking stent 32 decrease from large to small. Imaging anchoring integration components 2 are provided at both ends of the main stent 1. Each imaging anchoring integration component 2 includes imaging tantalum rings at both ends of the main stent 1. The imaging tantalum rings are segmented annular structures, comprising seven arc segments evenly spaced circumferentially, with gaps between adjacent arc segments for tissue ingrowth. An anchoring element 23 is provided on the outer surface of the tantalum ring facing the blood vessel wall. The anchoring element 23 includes a polyphenol / metal network coating on the surface of the tantalum ring and a hollow anchoring protrusion 232 disposed on the outer surface of the polyphenol / metal network coating facing the blood vessel wall. A tissue elongation port 233 is formed on the surface of the hollow anchoring protrusion 232. The imaging anchoring integration element 2 enables high-contrast imaging and positioning of the main scaffold 1 in CT images, while simultaneously forming a mechanical-biological dual anchoring between the main scaffold 1 and the blood vessel wall to prevent long-term displacement.

[0068] A linkage stent 22 is fixedly connected to the right side of the first and second contrast-enhancing tantalum rings, and another linkage stent 22 is connected to the left side of the second contrast-enhancing tantalum ring. The linkage stent 22 consists of two symmetrically arranged C-shaped arc segments, fixed back-to-back, forming an X-shaped cross linkage stent. The linkage stent 22 on the first contrast-enhancing tantalum ring is fixedly connected to the left end of the main stent 1. The linkage stent 22 on the left side of the second contrast-enhancing tantalum ring is fixedly connected to the right end of the main stent 1, and the linkage stent 22 on the right side of the second contrast-enhancing tantalum ring is fixedly connected to the left end of the thrombolytic stent 31. The right end of the thrombolytic stent 31 is connected to the left end of the flow-blocking stent 32, and the right end of the flow-blocking stent 32 is connected to the annular flow-blocking ring 33. The flow-blocking stent 32 and the flow-blocking ring 33 together form a frustum-shaped structure. An annular gap is formed between the thrombolytic stent 31 and the vessel wall, with an annular groove in its middle. This annular gap, in conjunction with its own annular groove, forms a thrombolytic cavity. The thrombus-dissolving stent 31, the flow-blocking stent 32, and the flow-blocking ring 33 work together to effectively intercept and divert thrombi in the blood flow, preventing the occurrence of distal embolism events.

[0069] The working principle of this embodiment is as follows: During delivery, the entire system is in a compressed state. The main stent 1, the thrombectomy stent 31, and the shunt stent 32 are gathered together through their woven mesh structure, and the linkage stent 22 is in a contracted configuration, constraining the radiopaque tantalum rings at both ends of the main stent 1. When the system is delivered to the target blood vessel and released, the main stent 1 and the thrombectomy stent 31 expand synchronously under their own radial force, adhering to the blood vessel wall. The expansion of the main stent 1 triggers the synchronous expansion of the linkage stent 22, causing deformation, restoring its preset X-shaped configuration, and pushing the radiopaque tantalum rings at both ends to expand radially synchronously, bringing them close to the blood vessel wall. The radiopaque tantalum rings with high atomic number produce high-contrast radiopaque spots in CT images for positioning. At the same time, the anchoring protrusion 232 in the anchoring member 23 contacts the blood vessel wall, achieving preliminary mechanical anchoring. Subsequently, the vascular intima tissue can grow into the internal tissue infiltration lumen through the tissue infiltration hole 233 on the surface of the anchoring protrusion 232, forming biological fixation, thereby preventing long-term stent displacement. The expansion of the main stent 1 triggers the simultaneous deployment of the thrombolytic stent 31 and the thrombectomy stent 32. The thrombectomy ring 33 returns to its circular shape, with a diameter smaller than that of the main stent 1, allowing only normal blood cells such as red blood cells, white blood cells, and platelets to pass freely. This physically blocks larger thrombi in the bloodstream. Under the guidance of the spirally distributed thrombectomy stent 32, the blocked thrombi move along a spiral path to the area where the thrombolytic stent 31 is located. The thrombolytic gap between the thrombolytic stent 31 and the vessel wall, along with its own annular groove, work together to accommodate the thrombi guided there and direct them to the vicinity of the vessel wall for ablation by the fibrinolytic system, preventing them from flowing distally and causing embolism.

[0070] Throughout the process, the zwitterionic coating applied to the surfaces of the main stent 1, the thrombolytic stent 31, and the shunt stent 32 inhibits protein adsorption by forming a hydration layer. Simultaneously, the polyphenol / metal network coating on the surface of the radiopaque tantalum ring functions as an anticoagulant and promotes endothelialization. The two coatings work together to prolong clotting time, promote endothelial cell coverage, and reduce inflammatory responses, thus supporting post-implantation biocompatibility.

[0071] Example 2: Based on Example 1, the tissue elongation port 233 is interconnected with the tissue elongation cavity formed inside the hollow anchoring protrusion 232. The hollow anchoring protrusion 232 is prepared using a template method: firstly, a polystyrene microsphere template with a diameter of 20μm~100μm is pre-placed on the surface of the polyphenol / metal network coating; then, a precursor solution containing polyphenols and metal ions is sprayed on; after the polyphenol / metal network coating has cured, the polystyrene microsphere template is dissolved and removed using an organic solvent to form the hollow anchoring protrusion 232, with a wall thickness of 5μm~15μm and a tissue elongation cavity diameter of 10μm~80μm.

[0072] The surface of the anchoring protrusion 232 is further perforated with laser to form tissue ingrowth holes 233 with a diameter of 2μm~10μm, enabling communication between the tissue ingrowth cavity and the external environment. When the radiopaque tantalum ring expands radially with the main scaffold 1, the anchoring protrusion 232 first contacts the vessel wall, generating local compressive stress and achieving initial mechanical anchoring of the main scaffold 1. Subsequently, the vascular intima tissue gradually grows into the tissue ingrowth cavity through the tissue ingrowth holes 233 on the surface, and eventually fills the entire cavity, forming a structure similar to an anchor bolt. Compared with solid protrusions, the hollow design provides a larger space for tissue ingrowth and allows tissue to enter and fill from multiple directions, achieving three-dimensional biological fixation, effectively enhancing the bonding strength between the entire scaffold and the vessel wall, and effectively preventing long-term displacement.

[0073] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0074] It should also be noted that, in this document, the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the 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 of the invention. Furthermore, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations, nor should they be construed as indicating or implying relative importance. Moreover, the term "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device.

Claims

1. A surface-modified vascular stent integrating imaging positioning and active anchoring, characterized in that, The vascular stent includes: a main stent and a radiopaque anchoring assembly disposed on the main stent, wherein the radiopaque anchoring assembly includes a radiopaque ring, an anchoring element, and a linkage stent; wherein, The linkage stent is connected between the main stent and the imaging ring; the linkage stent is made of a first shape memory alloy material and is used to expand radially with the main stent after implantation into the blood vessel, and to drive the imaging ring to expand radially synchronously to fit close to the blood vessel wall; The imaging ring has a segmented annular structure, which includes multiple arc segment units distributed circumferentially, and tissue ingrowth gaps are formed between adjacent arc segment units. The tissue ingrowth gaps are configured to induce vascular intima tissue ingrowth to form a biological anchor. The anchoring element includes an anchoring protrusion disposed on the outer surface of the imaging ring. The anchoring protrusion includes a tissue growth lumen and a tissue growth aperture that are interconnected, such that after the imaging ring is radially expanded, the anchoring protrusion forms a mechanical anchor with the blood vessel wall, and allows vascular intima tissue to grow into the tissue growth lumen through the tissue growth aperture to form a deep biological anchor.

2. The surface-modified vascular stent integrating imaging positioning and active anchoring according to claim 1, characterized in that, The developing ring comprises tantalum material or is made of tantalum material.

3. The surface-modified vascular stent integrating imaging positioning and active anchoring according to claim 1, characterized in that, The anchoring element further includes a functional coating applied to the surface of the developing ring; wherein the anchoring protrusion is disposed on the outer surface of the functional coating.

4. The surface-modified vascular stent integrating imaging positioning and active anchoring according to claim 1, characterized in that, The linkage support includes two symmetrically arranged arc-shaped spring arms. The two arc-shaped spring arms are fixed back to back and connected to form a cross linkage structure. The cross linkage structure is configured to restore a preset cross configuration when the main support is radially expanded, driving the developing ring to expand radially outward.

5. The surface-modified vascular stent integrating imaging positioning and active anchoring according to claim 1, characterized in that, The tissue extension port is provided in multiple ways to allow vascular endothelial tissue to enter the tissue extension lumen from multiple directions; and / or, each of the arc segment units is provided with the anchoring protrusion in a one-to-one correspondence.

6. A surface-modified vascular stent integrating imaging positioning and active anchoring according to any one of claims 1-5, characterized in that, The vascular stent also includes a defense mechanism, which includes: A thrombolytic stent is connected to the main stent, and the outer diameter of the thrombolytic stent is smaller than the outer diameter of the main stent, so that a thrombolytic gap is formed between the thrombolytic stent and the vessel wall after the thrombolytic stent and the main stent are radially expanded. A flow-blocking bracket is connected to the thrombus-removing bracket, and the flow-blocking bracket extends along a spiral path; A flow-blocking ring, connected to the flow-blocking bracket, wherein the flow-blocking ring is made of a second shape memory alloy material; The intercepting ring returns to its ring-shaped configuration when each stent is radially deployed to intercept thrombi in the blood flow. The intercepted thrombi are guided along the spiral path of the intercepting stent to the thrombectomy gap formed by the thrombectomy stent, where they are ablated by the fibrinolytic system of the vascular wall.

7. The surface-modified vascular stent integrating imaging positioning and active anchoring according to claim 6, characterized in that, The thrombolytic stent has a tapered shape with a gradually changing outer diameter along the blood flow direction; The thrombus-relieving bracket has an annular groove in the middle, and the annular groove and the thrombus-relieving gap together form a thrombus-relieving cavity.

8. The surface-modified vascular stent integrating imaging positioning and active anchoring according to claim 6, characterized in that, The flow-blocking bracket extends spirally from the flow-blocking ring toward the thrombus-removing bracket.

9. The surface-modified vascular stent integrating imaging positioning and active anchoring according to claim 6, characterized in that, Two developing rings are provided; wherein, the first developing ring is provided with the linkage bracket on one side, and the first developing ring is fixed to the end of the main body bracket away from the thrombus-removing bracket by the linkage bracket; the second developing ring is provided with the linkage bracket on both opposite sides, one side of the second developing ring is connected to the other end of the main body bracket by the linkage bracket on its side, and the other side of the second developing ring is connected to the thrombus-removing bracket by the linkage bracket on its side.

10. The surface-modified vascular stent integrating imaging positioning and active anchoring according to claim 6, characterized in that, The surfaces of the main support, the thrombus-removing support, and the flow-stopping support are all coated with zwitterionic coatings.

Images