Positioning support for convenient fixing and safe removal in human blood vessels

Abstract

This invention discloses a positioning stent for convenient fixation and safe removal within human blood vessels, relating to the field of surgical medical device technology. The positioning stent comprises: a metal wire stent with multiple pointed positioning spikes, each spike including an inner metal wire and a covering layer; the inner metal wire is connected to the metal wire of the metal wire stent, the diameter of the inner metal wire being smaller than the diameter of the metal wire of the metal wire stent; the covering layer is conical and made of a biodegradable material; the tips of the inner metal wires and the tips of the covering layer are spaced a predetermined distance apart, and the middle portion of the inner metal wire forms a spiral portion; after the covering layer degrades, the spiral portion changes from a compressed state to an extended state, allowing the inner metal wire to pierce the blood vessel wall, with a predetermined gap between the blood vessel wall surface and the surface of the metal wire stent. This invention achieves reliable stent fixation and safe removal.

Description

Technical Field

[0001] This invention relates to the field of surgical medical device technology, and in particular to a positioning stent that is convenient to fix and safely remove from human blood vessels. Background Technology

[0002] Under physiological influences, various forms of blockage or narrowing can occur in human blood vessels, such as sudden thrombosis. Therefore, interventional stent placement is currently a routine treatment method. Although interventional stent treatment is rapid in emergency situations, several problems still exist after placement. For example, under conditions of high blood flow and high blood pressure, stent displacement can occur, especially in elderly patients whose blood vessels have reduced elasticity. Additionally, due to the body's natural response, stents may spread to the surface, further narrowing the stenotic area. Furthermore, patients need to take long-term medication to prevent rejection. To minimize these problems, removing the stent from the blood vessel is a new trend.

[0003] Existing technology has developed stents with high-rigidity and high-strength barbs that embed into the blood vessel wall to fix the stent and prevent displacement. However, if the stent needs to be removed, these barbs can tear the blood vessel wall if the stent shifts. Thus, "fixation" and "safe removal" of the stent become contradictory. Therefore, how to ensure that the stent is not easily displaced after insertion and can be easily and safely removed when needed has become an urgent technical problem to be solved. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, the present invention provides a positioning stent that is convenient to fix and safely removed from human blood vessels, which can perfectly solve the technical problems mentioned in the background art.

[0005] One embodiment of the present invention provides a positioning stent that is convenient to fix and safely removed from a human blood vessel, comprising: a wire stent (1) that can expand radially within a human blood vessel, wherein the wire stent (1) is provided with a plurality of positioning spikes (2) with pointed tips, wherein the positioning spikes (2) include a metal inner wire (3) and a covering layer (4) covering the metal inner wire (3); the metal inner wire (3) is connected to the metal wire of the wire stent (1), the diameter of the metal inner wire (3) is smaller than the diameter of the metal wire of the wire stent (1), and the covering layer (4) is conical. The stent is shaped and made of biodegradable material. The tip of the metal inner wire (3) and the tip of the covering layer (4) are spaced apart by a predetermined distance. The middle part of the metal inner wire (3) forms a spiral part (5). After the covering layer (4) of the positioning spur (2) that pierces the blood vessel wall degrades, the spiral part (5) changes from a compressed state to an extended state, thereby releasing elastic force to increase the length of the metal inner wire (3) and then piercing the blood vessel wall to achieve the positioning of the stent. After the stent is positioned in the blood vessel, there is a predetermined gap between the blood vessel wall and the surface of the metal wire stent (1).

[0006] Furthermore, the inner metal wire (3) is provided with a ring (7) at one end near the metal wire support (1). The ring (7) is connected to the metal wire of the metal wire support (1). The covering layer (4) covers and fixes the ring (7) and the connection between the ring (7) and the metal wire together. After the covering layer (4) degrades, a movable connection is formed between the ring (7) and the metal wire of the metal wire support (1).

[0007] Furthermore, the covering layer is provided with a convex ring (6) for controlling the depth of the positioning needle (2) piercing the blood vessel wall.

[0008] Furthermore, the distance between the front surface of the convex ring (6) near the tip of the covering layer (4) and the tip of the covering layer (4) is 0.1 to 0.25 mm.

[0009] Furthermore, the angle between the positioning spike (2) and the axis of the wire support (1) is 20° to 90°.

[0010] Furthermore, the plurality of positioning spikes (2) are arranged at equal intervals along the axial direction of the wire support (1).

[0011] Furthermore, the plurality of positioning spikes (2) are arranged at equal intervals along the circumference of the wire support (1).

[0012] Furthermore, the predetermined gap between the blood vessel wall and the surface of the wire stent (1) is 0.1-0.5 mm.

[0013] Furthermore, the distance between the tip of the metal inner wire (3) and the tip of the covering layer (4) is 0.05 to 0.15 mm.

[0014] Furthermore, the metal inner filament (3) is made of a biodegradable metal material, and the degradation time of the metal inner filament (3) is later than the degradation time of the coating layer (4).

[0015] The present invention provides a positioning stent that is convenient to fix and safely removed from human blood vessels, which has the following beneficial effects:

[0016] (1) Excellent and reliable initial positioning effect was achieved. By setting a positioning needle with a biodegradable coating, the positioning needle has sufficient strength and rigidity in the early stage of stent implantation, which can effectively penetrate the blood vessel wall, prevent stent displacement, and ensure the stability of the implantation position;

[0017] (2) It greatly improves the safety of stent implantation and removal. As the biodegradable coating gradually degrades in the body, the rigidity and strength of the positioning needle decrease, making it easier to bend and deform. When removing the stent, the positioning needle can bend compliantly with the stent displacement, which greatly reduces the risk of scratching and tearing the blood vessel wall and effectively prevents complications such as vascular damage and bleeding;

[0018] (3) Automatic transition of positioning strength is achieved. After the coating layer degrades, the smaller diameter metal inner wire can still provide a certain positioning function under the action of the scaffold expansion force, while its flexibility is greatly increased. This automatic transition from "rigid fixation" to "flexible maintenance" takes into account both the stability of medium and long-term implantation and the safety of final removal;

[0019] (4) The insertion depth is precisely controlled, avoiding the risk of damage to the blood vessel wall. The conical coating and the convex ring structure near the front end can generate resistance that increases with depth when the positioning needle penetrates the blood vessel wall, and is eventually blocked by the surface of the blood vessel wall, just like a "depth limiter", which effectively prevents the positioning needle from penetrating too deeply or piercing the blood vessel wall;

[0020] (5) Effectively inhibits excessive endothelial proliferation, facilitating later stent removal. The tiny gaps formed between the stent surface and the vessel wall by the limiting structure can prevent endothelial cells from climbing over and covering the stent surface. This not only makes the stent easier to remove when needed, but also avoids fragmentation caused by tearing the endothelial covering, further improving surgical safety;

[0021] (6) It provides flexible implementation schemes to meet different clinical needs. By selecting different types of stents, such as the distribution of the positioning needles and the angle between them and the stent axis, doctors can choose the optimal stent configuration scheme according to the specific vascular anatomy and hemodynamic state, thereby enhancing the clinical applicability of the product. Attached Figure Description

[0022] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0023] Figure 1 This is a cross-sectional view of the positioning stent provided in one embodiment of the present application, which is convenient to fix and safely removed from human blood vessels, during positioning within the blood vessel;

[0024] Figure 2 yes Figure 1 A magnified view of the mid-positioning needle at point A;

[0025] Figure 3 This is a cross-sectional view of the positioning stent provided in another embodiment of this application, which is convenient to fix and safely removed from human blood vessels, during positioning within the blood vessel;

[0026] Figure 4 yes Figure 3 A magnified view of the mid-positioning needle at point B;

[0027] Figure 5 This is a cross-sectional view of the positioning stent provided in another embodiment of this application, which is convenient to fix and safely removed from human blood vessels, during positioning within the blood vessel;

[0028] Figure 6 yes Figure 5 A magnified view of the mid-positioning needle at point C;

[0029] Figure 7 This is a cross-sectional view of the positioning stent provided in another embodiment of this application, which is convenient to fix and safely removed from human blood vessels, during positioning within the blood vessel;

[0030] Figure 8 yes Figure 7 A magnified view of the centrally positioned needle at point D. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” used in the embodiments of this invention are also intended to include the plural forms unless the context clearly indicates otherwise.

[0033] It should be understood that although the terms first, second, third, etc., may be used to describe the acquisition modules in the embodiments of the present invention, these acquisition modules should not be limited to these terms. These terms are only used to distinguish the acquisition modules from each other.

[0034] It should be noted that the directional terms such as "upper," "lower," "left," and "right" used in the embodiments of the present invention are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of the present invention. Furthermore, in the context, it should be understood that when it is mentioned that an element is formed "upper" or "lower" of another element, it can not only be formed directly "upper" or "lower" of the other element, but also indirectly "upper" or "lower" of the other element through an intermediate element.

[0035] See Figure 1-8 This application provides a positioning stent that is conveniently fixed and safely removed from human blood vessels. Its basic structure includes a wire stent 1 that can expand radially within human blood vessels. The wire stent 1 can be spiral, braided, or made of laser-etched metal tube.

[0036] See Figure 1 , Figure 3 , Figure 5 , Figure 7 The core idea of ​​this application is to provide multiple pointed positioning needles 2 on a wire support 1. Each positioning needle 2 includes an inner metal wire 3 and a covering layer 4 encapsulating the inner metal wire 3. The inner metal wire 3 is connected to the wire of the wire support 1, and its diameter is set to be smaller than that of the wire of the wire support 1. The covering layer 4 is made of a biodegradable solid material (e.g., polylactic acid PLA, polyglycolic acid PGA, or their copolymer PLGA). The reason for this design is to hide the sharp tip of the inner metal wire 3 inside the solid material of the covering layer 4, forming a tiny cavity or delay zone. In the initial state, the conical tip of the biodegradable covering layer 4 bears all the insertion function and mechanical support. Only when the tip of the covering layer 4 has fully degraded and retracted to the tip position of the inner metal wire 3 will the inner metal wire 3 begin to directly contact and act on the vascular tissue. If its tip is directly exposed and responsible for the initial insertion, it's like trying to puncture a tire with a soft sewing needle—it's very easy for it to bend, leading to insertion failure and the stent not being able to anchor effectively. Biodegradable materials, on the other hand, have high strength and rigidity initially. The capsule made of these materials acts like a strong drill or pioneer, effectively overcoming the initial resistance of the blood vessel wall and successfully penetrating to the predetermined depth, providing the stent with immediate and robust stability.

[0037] In practical use, the wire stent 1 is delivered to the designated location via a delivery device and unfolds within the blood vessel. A portion of the tip of the positioning needle 2 pierces the vessel wall. Because the inner metal wire 3 of the positioning needle 2 has a biodegradable coating 4, after being placed within the blood vessel for a period of time, the biodegradable coating 4 gradually degrades, and the strength and rigidity of the positioning needle 2 gradually decrease. If the positioning stent needs to be removed at this point, the positioning needle 2, with its reduced strength and rigidity, is more easily deformed or bent and moves obliquely with the displacement of the positioning stent. This oblique movement after deformation or bending greatly reduces the damage to the blood vessel wall caused by the tip of the positioning needle 2. If the positioning stent remains within the blood vessel for a longer period, the coating 4 of the positioning needle 2 may be almost completely degraded. At this point, only the smaller diameter inner metal wire 3 remains of the positioning needle 2. Under the expansion force of the wire stent 1, it still retains a certain positioning function, but is more easily deformed or bent. This means that the positioning stent is easier to remove, and the damage to the blood vessel wall is less, significantly improving the safety of its use.

[0038] Furthermore, the covering layer 4 is manufactured in a conical shape. For example, the positioning spur 2 may be entirely conical, or the head of the positioning spur 2 may be conical while other parts are cylindrical, or other parts of the head may be conical. The reason for this design is that the inclined side of the cone creates greater resistance as the positioning spur 2 penetrates the blood vessel wall, thus preventing the positioning spur 2 from penetrating the blood vessel wall too deeply or causing bleeding. Because of the resistance of the cone, the positioning spur is designed not to completely penetrate the blood vessel wall. After the positioning stent is positioned within the blood vessel, a small gap will exist between the blood vessel wall and the surface of the wire stent 1, preferably 0.1~0.5mm, but other gap ranges are also possible. Figure 2 , Figure 4 , Figure 6 , Figure 8 As shown, the presence of this tiny gap can prevent the metal wire stent 1 from being covered by the skin due to biological reactions in the human blood vessels. This also makes it easier to remove the positioning stent and avoids the generation of fragments due to tearing of the skin when removing the positioning stent, thus improving the safety of using the positioning stent.

[0039] See Figure 4The positioning needle 2 has a convex ring 6 on its covering layer 4. The distance between the front surface of the convex ring 6 near the tip of the covering layer 4 and the tip of the covering layer 4 is preferably set to 0.1~0.25mm. In this embodiment, "front" refers to the tip of the covering layer 4, and "rear" refers to the point of the covering layer 4 near the wire support 1. After the positioning needle 2 penetrates the human blood vessel wall, the front surface of the convex ring 6 abuts against the surface of the blood vessel wall, thereby preventing the positioning needle 2 from further penetrating into the blood vessel wall. It should be noted that the above numerical range is carefully selected, as it is much smaller than the thickness of most functional blood vessel walls (e.g., the thickness of the coronary artery wall is about 0.5-1.0mm), ensuring that the positioning needle 2 is only anchored in the intima layer or the most superficial media layer of the blood vessel, absolutely avoiding penetrating damage, and providing a built-in, absolutely reliable safety boundary for the doctor's operation. Meanwhile, because the insertion depth is strictly and uniformly limited to this tiny range, the anchoring force provided by all positioning needles 2 is consistent and predictable. This avoids abnormally high anchoring forces caused by individual positioning needles accidentally inserting too deeply, and also prevents insufficient anchoring force caused by shallow insertion. This consistency of anchoring force is crucial for the overall stability and performance prediction of the stent. In addition, as mentioned earlier, the predetermined gap of 0.1~0.5mm between the stent body and the vessel wall is directly caused by the effective insertion depth of the positioning needle 2 being limited by the convex ring 6. In other words, by precisely controlling the position of the convex ring, the crucial tiny gap between the stent and the vessel wall is indirectly and precisely controlled.

[0040] See Figure 6In another preferred embodiment of this application, a spiral portion 5 is formed in the middle of the inner metal wire 3. Specifically, during stent manufacturing, the inner metal wire 3 is pre-wound into a small helical spring-like structure, i.e., the spiral portion 5. Subsequently, a biodegradable material is coated onto the outside of the inner metal wire 3, forming a coating layer 4. Crucially, after curing, the coating layer 4 tightly wraps and binds the compressed spiral portion 5. At this point, the spiral portion 5 stores elastic potential energy due to its deformation, but it cannot extend because the surrounding robust coating layer 4 acts like a cage, locking it in place. The entire positioning stent 2 is then a rigid whole. After the stent is implanted into the blood vessel, the coating layer 4 begins its biodegradation process, a gradual weakening of material properties and volumetric erosion over time. When the covering layer 4 degrades to a certain extent, and the mechanical restraint force on the internal spiral portion 5 weakens to below the elastic recovery force of the spiral portion 5, the spiral portion 5 rapidly transitions from a compressed state to a partially or fully extended state. This extension of the spiral portion 5 pushes the metal inner wire 3 at its tip to produce a slight axial forward displacement. This displacement precisely compensates for any loss in insertion depth due to the degradation of the front end of the covering layer 4. It acts like a miniature piston, pushing forward a small step at a critical moment, ensuring that the tip of the metal inner wire 3 always effectively contacts or shallowly penetrates the vessel wall. During stent removal, this spiral portion 5 serves as an additional flexible buffer and deformation energy-absorbing zone. When the tip of the metal inner wire 3 encounters resistance, not only does the tip bend, but the spiral portion 5 can also be further compressed or extended to absorb energy, allowing the entire positioning puncture 2 to undergo a greater degree of compliant deformation, thus making its removal from the vessel wall smoother and less damaging.

[0041] See Figure 8Another preferred embodiment of this application involves a ring 7 at one end of the inner metal wire 3, which is movably connected to the metal wire of the wire support 1. Specifically, during manufacturing, the ring 7 at the end of the inner metal wire 3 can be sleeved or hooked onto the metal wire of the wire support 1. At this point, it is only a preliminary hooking or sleeve, and is itself movable. Subsequently, a biodegradable material is encapsulated, completely wrapping and solidifying the ring 7 and the contact area between the ring 7 and the support wire in a solid encapsulation layer 4. The biodegradable material acts as a structural adhesive and rigid clamp, firmly fixing the ring 7 to the support wire to form a rigid, integrated connection point. This ensures that in the initial stage of stent implantation and expansion, force can be transmitted from the stent body to the entire positioning needle 2 without loss or delay, allowing it to obtain sufficient thrust to penetrate the blood vessel wall and complete reliable initial anchoring. After implantation, the covering layer 4 gradually degrades over time. When the biodegradable material surrounding the connection between the ring 7 and the stent wire decomposes and disappears, the structural adhesive and rigid clamping functions are lost. At this point, the ring 7 and the stent wire regain and retain their initial, unrestrained, movable connection. This movable connection manifests as a hinge (i.e., rotation around the stent wire) or a sliding pair (i.e., slight sliding along the stent wire). The connection point changes from a fixed, rigid joint to a movable joint, providing fundamental structural freedom for subsequent safe removal.

[0042] The specific principle is:

[0043] (1) If the root of the positioning needle 2 is fixed, when the stent is removed, the tip of the positioning needle 2 will be subject to the resistance of the blood vessel wall tissue. Its only exit path is to strictly exit along its central axis in the opposite direction. This is like pulling a straight nail out of wood, which requires overcoming huge static friction and tissue locking force, and is very likely to cause scratches and tears to the blood vessel wall. However, the movable connection formed by the ring 7 in this embodiment allows the entire metal inner wire 3 to rotate at the root. That is, when the stent is withdrawn, the resistance will force the root of the metal inner wire 3 to rotate around the stent wire, causing it to tilt. This tilting instantly changes the exit direction from a high-resistance axial straight pull to a low-resistance oblique slip, thus exiting in a path of least resistance, greatly reducing the force required for the exit process and fundamentally avoiding longitudinal scratches.

[0044] (2) The combination of the movable connection and the flexibility of the metal inner wire 3 creates optimal follow-up conditions. When the stent moves, the tip of the metal inner wire 3 can rotate due to the movable connection and bend due to its own flexibility, sliding out of the tissue like a compliant tentacle. This high degree of compliant stress ensures that damage to the vascular intima is minimized, almost completely eliminating the plow-like damage caused by traditional rigid hooks, and greatly improving the safety of the removal surgery.

[0045] (3) Human blood vessels are not ideal straight channels, and often have bends and bifurcations. When removing the stent through a tortuous path, the movable connection formed by the ring 7 provides additional degrees of freedom, allowing each positioning spur 2 to independently adjust its angle and posture to adapt to changes in local blood vessel geometry. This avoids the huge resistance caused by multiple positioning spurs 2 being stuck at the bend, making the whole removal process smoother and reducing the difficulty and risk of the surgical operation.

[0046] (4) The root flexibility (rotational and other movable connections) provided by the ring 7 and the rod flexibility (i.e., microscopic bending) provided by the spiral part 5 and the inner metal wire 3 together constitute a dual flexibility system. When the positioning bracket is removed, the deformation of the positioning spur 2 is no longer limited to a certain point, but is a smooth, distributed flexible deformation from the root to the tip. This further disperses stress, absorbs energy, makes the withdrawal action smooth, and reduces the possibility of tissue damage to the theoretical minimum.

[0047] Furthermore, a distance of 0.05~0.15mm is reserved between the tip of the metal inner wire 3 of the positioning spike 2 and the tip of the covering layer 4. This design avoids an anchoring vacuum period during the degradation of the covering layer 4. Without this distance, if the tip of the covering layer 4 is flush with the tip of the metal inner wire 3, the strength and sharpness of the front end of the covering layer 4 will decrease as it begins to degrade, immediately weakening the anchoring force. The metal inner wire 3 is not ready to take over, and the support may shift during this stage. The 0.05~0.15mm distance means that the covering layer 4 needs time to complete the degradation of this distance. During this time, the internal spiral portion 5 gradually releases its constraints due to the overall degradation of the covering layer 4, preparing to release elastic energy. When the covering layer 4 degrades to the tip of the metal inner wire 3, the metal inner wire 3 is slightly extended by the spring mechanism, timely taking over the weakened covering layer 4 and continuing to provide a gentle but effective anchoring force. This achieves a smooth, seamless transition from rigid anchoring to flexible maintenance. Therefore, this minute spacing is a carefully calculated time window in this invention, ensuring that the metal inner wire 3 is not exposed too early, affecting initial fixation, nor exposed too late, causing interruption of anchoring force. It allows for a precise correlation between the mechanical property transformation of the positioning stent and the in vivo degradation kinetics of the biodegradable material. Based on the expected degradation cycle, physicians can roughly determine the smoothest and safest time to remove the stent. Furthermore, even after the covering layer 4 has completely degraded, the tip of the metal inner wire 3 exits from a limited microchannel pre-drilled in the tissue by the covering layer 4. Because the metal inner wire 3 is extremely flexible, it exits by bending rather than cutting. This spacing design ensures that the insertion depth of the metal inner wire 3 remains superficial and controllable throughout, further reducing the potential risk of it acting as a scratching object during removal.

[0048] Furthermore, the angle between the axis of the positioning needle 2 and the wire support 1 can be selected and adjusted between 20° and 90°. The attached figure shows the 90° (i.e., vertical) state. Different angles will change the direction of the component force of the support expansion force on the positioning needle, thereby adapting to the positioning needs of different vascular sites (such as straight or curved vessels).

[0049] Furthermore, multiple positioning needles 2 can be evenly spaced along the axial direction and / or circumferential direction of the wire support 1. This regular layout provides uniform anchoring force. In some cases, depending on the morphology or lesion characteristics of specific parts of the blood vessel (such as curvature, blood flow velocity, and differences in the vessel wall), a non-uniformly spaced arrangement can be used to provide differentiated fixation support. In actual use, this also gives doctors different choices depending on the specific situation.

[0050] Furthermore, to simultaneously ensure the anchoring of the wire stent 1 and its smooth and safe removal, preferably, both the inner wire 3 and the covering layer 4 are made of biodegradable materials. For example, the inner wire 3 is made of biodegradable magnesium alloy or zinc-magnesium alloy, and the covering layer 4 is made of biodegradable materials such as polylactic acid (PLA), polyglycolic acid (PGA), or their copolymers (PLGA). More preferably, the degradation time of the two is set so that the degradation time of the inner wire 3 is later than that of the covering layer 4, so that the covering layer 4 degrades first, and then the inner wire 3 is anchored in the blood vessel wall. After a predetermined time after the complete degradation of the covering layer 4 (e.g., 1-3 months or other degradation cycles selected according to the actual situation), the inner wire 3 partially or completely degrades. This not only does not affect the anchoring of the positioning needle 2 and the wire stent 1, but also makes it easier to remove the wire stent 1.

[0051] The above-mentioned technical solution of this application has made very important improvements to the existing vascular dilation stents. It not only makes the stent easier to position in the blood vessel, but more importantly, it makes it easier to remove and greatly improves the safety during use and removal.

[0052] The above description is merely a preferred embodiment of the present invention. Those skilled in the art should understand that the scope of disclosure in this invention is not limited to the specific combination of the above-described technical features, but should also cover other technical solutions formed by any combination of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this invention.

Claims

1. A positioning stent that is conveniently fixed and safely removed from human blood vessels, comprising a wire stent (1) capable of radial expansion within human blood vessels, characterized in that: The metal wire support (1) is provided with a plurality of positioning spikes (2) with pointed tips. The positioning spikes (2) include metal inner wires (3) and a covering layer (4) covering the outside of the metal inner wires (3). The inner metal wire (3) is connected to the metal wire of the metal wire support (1). The diameter of the inner metal wire (3) is smaller than the diameter of the metal wire of the metal wire support (1). The covering layer (4) is conical and made of biodegradable material. The tip of the inner metal wire (3) and the tip of the covering layer (4) are spaced apart by a predetermined distance. The middle part of the inner metal wire (3) forms a spiral part (5). After the coating layer (4) of the positioning puncture (2) that pierces the blood vessel wall degrades, the spiral part (5) changes from a compressed state to an extended state, thereby releasing elastic force to increase the length of the metal inner wire (3), and then piercing the blood vessel wall to achieve the positioning of the positioning stent; after the positioning stent is positioned in the blood vessel, there is a predetermined gap between the blood vessel wall surface and the surface of the metal wire stent (1).

2. The positioning stent for convenient fixation and safe removal within human blood vessels according to claim 1, characterized in that: The inner metal wire (3) has a ring (7) at one end near the metal wire support (1). The ring (7) is connected to the metal wire of the metal wire support (1). The covering layer (4) covers and fixes the ring (7) and the connection between the ring (7) and the metal wire. After the covering layer (4) degrades, a movable connection is formed between the ring (7) and the metal wire of the metal wire support (1).

3. A positioning stent for convenient fixation and safe removal within human blood vessels according to claim 1 or 2, characterized in that: The covering layer is provided with a convex ring (6) for controlling the depth of the positioning needle (2) piercing the blood vessel wall.

4. A positioning stent for convenient fixation and safe removal within human blood vessels according to claim 3, characterized in that: The distance between the front surface of the convex ring (6) near the tip of the covering layer (4) and the tip of the covering layer (4) is 0.1 to 0.25 mm.

5. A positioning stent for convenient fixation and safe removal within human blood vessels according to claim 1 or 2, characterized in that: The angle between the positioning spike (2) and the axis of the wire support (1) is 20° to 90°.

6. A positioning stent for convenient fixation and safe removal within human blood vessels according to claim 1 or 2, characterized in that: The plurality of positioning spikes (2) are arranged at equal intervals along the axial direction of the wire support (1).

7. A positioning stent for convenient fixation and safe removal within human blood vessels according to claim 1 or 2, characterized in that: The plurality of positioning spikes (2) are arranged at equal intervals along the circumference of the wire support (1).

8. A positioning stent for convenient fixation and safe removal within human blood vessels according to claim 1 or 2, characterized in that: The predetermined gap between the blood vessel wall and the surface of the wire stent (1) is 0.1-0.5 mm.

9. A positioning stent for convenient fixation and safe removal within human blood vessels according to claim 1 or 2, characterized in that: The distance between the tip of the metal inner wire (3) and the tip of the covering layer (4) is 0.05 to 0.15 mm.

10. A positioning stent for convenient fixation and safe removal within human blood vessels according to claim 1 or 2, characterized in that, The metal inner filament (3) is made of a biodegradable metal material, and the degradation time of the metal inner filament (3) is later than that of the coating layer (4).

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