filter

Abstract

This invention provides a filter comprising a proximal end, a distal end, and a filtration section connecting the proximal and distal ends. The proximal end of the filter is provided with an at least partially degradable auxiliary support member, which supports the middle portion of the proximal end near the implantation area after implantation. This invention provides an auxiliary support member capable of maintaining proximal alignment. The auxiliary support member is partially degradable, so that after providing initial support during implantation, some material degrades, thereby reducing the area of ​​endothelial migration and enabling successful retrieval.

Description

Technical Field

[0001] This invention relates to the field of interventional medical device technology, and more particularly to a filter. Background Technology

[0002] Pulmonary embolism (PE) is a common disease with a high mortality rate. Statistics show that the mortality rate of untreated PE is 20%-30%, with approximately 0.2% of new cases occurring in the population each year. Implantation of a vena cava filter (hereinafter referred to as the filter) has been clinically proven to be a safe and effective method for preventing PE, reducing its incidence.

[0003] Clinically, on the one hand, when the filter is implanted via the femoral vein approach, the tortuous sections of the femoral vein and common iliac vein cause the distal end of the filter to habitually deviate towards the opposite side of the approach during implantation. On the other hand, after the filter has been implanted in the inferior vena cava for a period of time, due to its structure, the filter is prone to tilting under the influence of blood flow and external forces. This causes the retrieval hook to adhere to the wall and become covered and encapsulated by endothelial cells to varying degrees, making it difficult to remove. Long-term implantation of filters in the human body carries certain risks, such as complications like vascular occlusion, recurrence of pulmonary embolism, filter breakage, and perforation. When the filter...

[0004] Currently, the industry primarily addresses the issue of filter implantation tilting by adding anti-tilting components to the structure of the implanted filter. While these anti-tilting components can prevent tilting during long-term implantation, they may introduce the risk of difficulty in retrieval after endothelial migration.

[0005] Therefore, how to prevent the filter from tilting while implanted in the blood vessel for a long time and how to retrieve it smoothly is a problem that urgently needs to be solved. Summary of the Invention

[0006] Therefore, it is necessary to propose a new filter to address the problem of existing filters being prone to deflection and misalignment, as follows:

[0007] A filter is provided, the filter including a proximal end, a distal end, and a connection between the proximal end and the distal end, wherein the proximal end of the filter is provided with an at least partially degradable auxiliary support member, the auxiliary support member supporting the proximal end near the middle of the implantation area after implantation.

[0008] In one embodiment, the auxiliary support includes an auxiliary connecting section fixedly connected to the proximal end and an auxiliary support section extending obliquely outward from the auxiliary connecting section.

[0009] In one embodiment, the auxiliary support section includes an inner transition section and an outer support section, the transition section and the support section extending in opposite directions in the axial direction.

[0010] In one embodiment, the transition segment extends obliquely toward the distal end in a radially outward direction, and the support segment extends obliquely toward the proximal end.

[0011] In one embodiment, the auxiliary support segment is degradable and supports the proximal end of the filter during initial implantation, and gradually degrades after the proximal end has stabilized.

[0012] In one embodiment, the auxiliary connecting segment extends distally at an angle from the inside to the outside.

[0013] In one embodiment, the support section of the auxiliary support segment is degradable, and the distance from the end of the transition section to the axis of symmetry of the filter is less than 2 / 3 of the distance from the support section to the axis of symmetry.

[0014] In one embodiment, the auxiliary support includes an auxiliary connecting segment fixedly connected to the proximal end, and an auxiliary support segment surrounding the auxiliary connecting segment.

[0015] In one embodiment, the auxiliary support section extends axially to form a threaded structure.

[0016] In one embodiment, the auxiliary support segment has a passivated free end.

[0017] Compared with existing technologies, the present invention provides a filter including a proximal end, a distal end, and a filtration section connecting the proximal end and the distal end. The proximal end of the filter is provided with an auxiliary support member that is at least partially degradable. This auxiliary support member supports the middle portion of the proximal end near the implantation area after implantation. The present invention provides an auxiliary support member capable of maintaining proximal alignment. The auxiliary support member is partially degradable, so that after providing initial support during implantation, some material degrades, thereby reducing the area of ​​endothelial migration and enabling successful retrieval. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the filter structure in Embodiment 1 of the present invention;

[0019] Figure 2 This is a schematic diagram of the filter in the state to be recycled in Embodiment 1 of the present invention;

[0020] Figure 3 This is a schematic cross-sectional view of the filter in its initial implantation state near the proximal end in Embodiment 1 of the present invention;

[0021] Figure 4 This is a schematic cross-sectional view of the filter near its proximal end in the state to be recycled in Embodiment 1 of the present invention;

[0022] Figure 5 This is a schematic diagram of a traditional filter.

[0023] Figure 6 This is a schematic diagram of the cross-sectional structure of the conventional filter of the present invention;

[0024] Figure 7 yes Figure 6 Enlarged view of region A in the middle;

[0025] Figure 8 This is a schematic diagram of the structure of the filter in the pre-recovery state near the proximal end in another embodiment of Embodiment 1 of the present invention;

[0026] Figure 9 This is a cross-sectional schematic diagram of the filter near the proximal end in the state to be recycled in another embodiment of Embodiment 1 of the present invention;

[0027] Figure 10 This is a schematic diagram of the proximal position structure of the filter in the initial state of implantation in Embodiment 2 of the present invention;

[0028] Figure 11 This is a schematic diagram of the near-end position structure of the filter in the state to be recycled in Embodiment 2 of the present invention;

[0029] Figure 12 This is a schematic diagram of the structure of the auxiliary support member in the initial state of implantation in another embodiment of Embodiment 2 of the present invention;

[0030] Figure 13 This is a schematic diagram of the near-end position of the filter in the state to be recycled in Embodiment 2 of the present invention. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0032] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0033] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0034] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0035] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0036] Additionally, it should be noted that in the field of interventional medical devices, the end of a medical device implanted in the human or animal body, or the delivery system that delivers the medical device, closer to the operator is generally referred to as the "proximal end," and the end farther from the operator is referred to as the "distal end." Based on this principle, the "proximal end" and "distal end" of any component of a medical device or delivery system are defined. "Axial direction" generally refers to the length direction of the medical device during delivery, and "radial direction" generally refers to the direction of the medical device perpendicular to its "axial direction." Based on this principle, the "axial direction" and "radial direction" of any component of a medical device are defined.

[0037] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0038] Example 1

[0039] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the filter 100 in Embodiment 1 of the present invention. The filter 100 includes a proximal end 110, a distal end 120, and a filtering section 130 connecting the proximal end 110 and the distal end 120. The filtering section 130 includes a first filtering unit 131, a second filtering unit 132, and a plurality of support rods 133 connecting the first filtering unit 131 and the second filtering unit 132. The first filtering unit 131 extends from the support rods 133 and converges at the proximal end 110, and the second filtering unit 132 extends from the support rods 133 and converges at the distal end 120. The support rods 133 extend generally along the axial direction. After implantation, the support rods 133 abut against the inner wall of the blood vessel to maintain the shape of the filter 100, thereby allowing the first filtering unit 131 and the second filtering unit 132 to open as wide as possible. In this embodiment, the proximal end 110 is the connection end between the filter 100 and the delivery device.

[0040] Preferably, the plurality of support rods 133 are evenly spaced around the line (i.e., axis) connecting the proximal end 110 and the distal end 120.

[0041] In another embodiment, the first filter unit 131 is formed by multiple Y-shaped filter rods converging at the proximal end 110, giving the first filter unit 131 a conical mesh structure. The second filter unit 132 is also formed by multiple Y-shaped filter rods converging at the distal end 120, giving the second filter unit 132 a conical mesh structure. The number of Y-shaped filter rods in the first filter unit 131 is half the number of Y-shaped filter rods in the second filter unit 132, making the filter 100 have an overall asymmetrical structure. This asymmetrical structure provides selectivity for pre-filtered thrombi, filtering only thrombi that could cause pulmonary embolism, thereby ensuring the long-term patency of the vena cava.

[0042] In this embodiment, please refer to further details. Figure 2-4 , Figure 2This is a schematic diagram of the filter 100 in the state to be recycled in Embodiment 1 of the present invention. Figure 3 This is a schematic cross-sectional view of the filter 100 in its initial implantation state near the proximal end 110 in Embodiment 1 of the present invention. Figure 4 This is a schematic cross-sectional view of the filter 100 in its pre-retrieval state near the proximal end 110 in Embodiment 1 of the present invention. The proximal end 110 of the filter 100 is tubular and includes a connecting area 111 at the end. The inner wall of the connecting area 111 is intact and includes a threaded structure. The threaded structure covers the entire connecting area 111 axially, thereby enabling a stable connection when threadedly engaged with the push rod. The key feature is that the surface of the connecting area 111 includes at least one degradable area 112 extending circumferentially and axially. After implantation for a certain period, the degradable area 112 gradually degrades, forming a groove 113, which functions as a retrieval hook. Therefore, in this embodiment, during the implantation stage, the entire proximal end 110 functions as the connecting area 111, with the threaded structure extending to cover the degradable area 112. After implantation, as the degradable area 112 gradually degrades, the proximal end 110 develops a groove 113, which functions as a retrieval hook to engage with the matching capture ring. Figure 1 The biodegradable region 112 is represented by a dashed line. Figure 1 The degradable region 112 in the middle forms after degradation Figure 2 The slot 113 in this embodiment includes an initial implantation state and a recovery state. In the initial implantation state, the outer surface of the proximal end 110 of the filter 100 is intact, and a threaded structure spanning the entire proximal end 110 is provided on the inner wall. In the recovery state, the proximal end 110 of the filter 100 includes at least one slot 113.

[0043] To further illustrate the function of the filter 100 in this embodiment, a conventional filter is used as a reference for explanation. The filter itself needs to complete two processes: implantation and retrieval. During implantation, the filter needs to be compressed into the tubular sheath first, and then transported to a predetermined position through the sheath before being withdrawn to achieve release and initial implantation. During movement within the sheath and when the sheath is withdrawn, the filter is limited by a push rod. Therefore, during the implantation process, it is necessary to ensure a stable connection between the filter and the push rod.

[0044] Please refer to Figure 5-7 , Figure 5 This is a structural diagram of a traditional filter 200. Figure 6 This is a schematic cross-sectional view of the conventional filter 200 of the present invention. Figure 7 yes Figure 6An enlarged schematic diagram of region A. Therefore, conventional filters 200 typically use a threaded structure at the proximal end 210 to engage and connect with the push rod. However, to reduce the implantation volume, the proximal end 210 of the conventional filter 200 must both ensure connection and function as a retrieval hook. Therefore, the proximal end 210 of the conventional filter 200 has a threaded area 211 and a retrieval area 212 arranged sequentially in the axial direction. The inner wall of the threaded area 211 has a threaded structure to facilitate connection with the push rod, and the retrieval area 212 has a retrieval hook or retrieval groove to facilitate engagement with the capture ring. The length of the proximal end 210 of the conventional filter 200 is at least the sum of the lengths of the threaded area 211 and the retrieval area 212. It should be noted that... Figure 3-5 The structure shown integrates the threaded area 211 and the recovery area 212, making it a relatively small design for a filter. However, since at least part of the recovery area 212 is completely exposed, it's impossible to install a threaded area in that area (objectively speaking, if threads were forcibly tapped, the thread engagement would be poor due to the empty side of the threaded area, making deflection and obstruction highly likely). Therefore, the threaded area 211 and the recovery area 212 of the conventional filter 200 function independently. To ensure the connection strength between the conventional filter 200 and the push rod, the threaded area 211 needs a certain basic length. Similarly, to expose sufficient space for recovery, the recovery area 212 also needs... To maintain a certain length, the conventional filter 200 must reserve sufficient axial length for both the threaded area 211 and the recovery area 212 to meet basic functions. Beyond meeting the basic axial length requirement, the longer the axial length reserved for the threaded area 211 and the recovery area 212, the better the connection strength and ease of retrieval. However, as an implant, the volume of the conventional filter 200 needs to be controlled within a certain range. Therefore, the conventional filter 200 faces the challenge of balancing preserving the axial length of the threaded area 211 and the recovery area 212 as much as possible while controlling their overall volume to reduce the burden on the human body. This is difficult to achieve when the threaded area 211 and the recovery area 212 are relatively independent.

[0045] In another embodiment, such as Figure 8-9 As shown, Figure 8 This is a schematic diagram of the structure of the filter 100 in the near-recovery state near the proximal end 110 in another embodiment of Embodiment 1 of the present invention. Figure 9This is a cross-sectional schematic diagram of the filter 100 in a state of awaiting recycling near the proximal end 110 in another embodiment of Embodiment 1 of the present invention. The surface of the proximal end 110 includes multiple discontinuous biodegradable regions 112 extending circumferentially and axially, thereby forming multiple slots 113 in different circumferential directions after degradation, which can better cooperate with the capture ring. It should be noted that, axially, the multiple slots 113 can even extend to cover most or the entire proximal end 110 of the filter 100, thereby greatly increasing the probability of being captured by the capture ring, which is almost impossible to achieve with ordinary filters.

[0046] In this embodiment, the degradable region 112 is made of a degradable metal material (such as a degradable zinc-based material) or a degradable polymer (such as polylactic acid).

[0047] In this embodiment, the middle part of the degradable region 112 is located at the far end of its end, so that the shape of the degradable region 112 extending along the tubular connection region 111 is approximately arc-shaped, and the top of the arc is located at the far end. That is, along the circumferential direction of the proximal end 110, the middle part of the degradable region 112 is recessed towards the far end, so that the opening of the slot 113 formed later is tilted towards the far end, thereby facilitating the movement of the capture ring towards the proximal end after locking and inserting it into the slot 113, thereby further allowing the filter 100 to be retracted into the sheath.

[0048] It should also be noted that since the groove 113 is formed after the degradable region 112 gradually degrades, it also avoids the filter 100 from being directly attached to the groove 113 after implantation, thereby extending the window period for the retrieval of the filter 100. Specifically, the retrieval hook of ordinary filters is irregularly shaped, and cells are prone to attach to it after implantation. The retrieval period setting of ordinary filters also needs to consider the situation that the retrieval hook is difficult to capture after being attached. However, in this embodiment, the groove 113 is formed after the degradable region 112 gradually degrades. When the degradable region 112 is first implanted, it is part of the connecting region 111 and the surface is a continuous and complete structure. The groove 113 will only appear after the degradable region 112 gradually degrades. Therefore, the filter 100 of this embodiment has better solved the problem of the risk of the degradable region 112 being attached, at least before the degradable region 112 degrades, thereby also helping to extend the overall retrieval period of the filter 100.

[0049] In another embodiment, the degradable zone 112 can be located near the far end of the connection zone 111, so that when the capture ring is used to capture, it can gradually shrink from the position of the first filter unit 131 that is close to the filter 100, which is easier to position than the traditional filter recovery hook that needs to be located at the farthest end.

[0050] In another embodiment, the support rod 133 is further provided with an extension rod for contacting the blood vessel wall. The function of the extension rod is to ensure that the filter contacts the blood vessel wall after implantation, keeping the support rod 133 away from the blood vessel wall, thereby preventing the problem of short recovery time window caused by the vascular intima climbing on the filter surface. The extension rod includes a transition section extending from the support rod 133 towards the blood vessel wall and an extended support section extending from the transition section, which is used to contact the blood vessel wall. This allows the extended support section to provide a more uniform and stable support force for the filter in the blood vessel, preventing the filter from tilting or shifting in the blood vessel, which would weaken the thrombus filtration effect and increase the risk of pulmonary embolism in postoperative patients; at the same time, it greatly reduces the incidence of filter rod puncturing the blood vessel wall. In other possible embodiments, two or more extension rods may also be provided on the intermediate connecting rod, and these extension rods can be fixed at any position on the intermediate connecting rod.

[0051] Example 2

[0052] This embodiment further improves the proximal region of the filter based on Embodiment 1.

[0053] During the use of inferior vena cava filters, filter misalignment frequently occurs. When misaligned, the rear end of the filter often leans against the inner wall of the vessel lumen, sometimes even causing vessel wall puncture, leading to failure in filtering venous thrombi and other complications. Furthermore, misaligned filters are prone to causing intimal tissue hyperplasia at the site of misalignment. Over time, this hyperplasia can even completely cover the filter's bifurcated structure, making filter retrieval difficult and resulting in high resistance.

[0054] Reference Figure 10-11 , Figure 10 This is a schematic diagram of the proximal position structure of the filter 300 in the initial implantation state in Embodiment 2 of the present invention. Figure 11 This is a schematic diagram of the near-end position structure of the filter 300 in the state to be recycled in Embodiment 2 of the present invention.

[0055] For filter 300, skewness and displacement mostly occur in the initial implantation stage. Specifically, the filter moves along the inner wall of the sheath to the designated position. The push rod is connected to the proximal end 310 of filter 300 to push the filter 300. Since the sheath itself needs to enter the blood vessel, the outer diameter of the sheath is smaller than the inner diameter of the blood vessel. Therefore, the compressed diameter of filter 300 is smaller than both the outer diameter of the sheath and the inner diameter of the blood vessel. Since the blood vessel extends in a curved manner, the sheath needs to extend along the blood vessel path. When the end of the sheath reaches the predetermined position, the end of the sheath naturally deviates to one side of the blood vessel. Thus, filter 300 achieves centering by adhering to the blood vessel wall with its own support rod. It should be noted that because the support rod expands to adhere to the blood vessel wall, the distal end of filter 300 is still roughly located in the central area of ​​the blood vessel after leaving the sheath due to the expansion of the support rod. However, as the sheath gradually moves backward, small deviations gradually accumulate and converge at the proximal end 310, which can easily lead to larger deviations, resulting in overall skewness.

[0056] To address the issue of excessive offset at the proximal end 310 of the filter 300, this embodiment provides an auxiliary support 330 at the proximal end 310 of the filter 300. The auxiliary support 330 includes an auxiliary connecting section 331 fixedly connected to the proximal end 310 and an auxiliary support section 332 extending obliquely outward from the auxiliary connecting section 331. Further, in this embodiment, the auxiliary support section 332 includes an inner transition section 333 and an outer support section 334. The transition section 333 and the support section 334 extend in opposite axial directions; in other words, from the inside out (radially outward), the transition section 333 extends obliquely towards the distal end, and the support section 334 extends obliquely towards the proximal end. When the auxiliary support 330 is fully opened, the support section 334 opens and presses against the blood vessel wall, thereby holding the proximal end 310, which is surrounded by the support section 334, against the middle of the blood vessel as much as possible, thus maintaining the coaxiality of the filter 300 and the blood vessel as much as possible during the implantation stage.

[0057] To avoid excessively large overall volume of the filter 300 during removal and to prevent endothelialization of the auxiliary support 330 with the blood vessel wall, making removal difficult, this embodiment sets the auxiliary support segment 332 as a biodegradable segment. Thus, upon initial implantation, the auxiliary support segment 332 can support the proximal end 310 of the filter 300, helping it stabilize. After gradual degradation, the adhesion formed by the filter 300's contact with the blood vessel wall helps maintain the filter 300 in a centered position. The proximal end 310 of the filter 300 only includes an additional auxiliary connecting segment 331. It should be noted that the auxiliary connecting segment 331 is retained so that the capture ring can be directly fitted when the filter 300 is removed. At the auxiliary connection segment 331, in addition, during the early stage after implantation, the auxiliary support segment 332 exerts significant stress on the vessel wall to assist in the alignment of the proximal end 310. If it is not degraded and removed simultaneously after the recovery period, the vessel wall and the auxiliary support segment 332 will have become almost inseparable by the end of the recovery period, making removal extremely difficult. This is also why conventional filter structures are difficult to set up with auxiliary alignment structures. In this embodiment, setting the auxiliary support segment 332 as a degradable segment solves this problem, and the volume of the filter 300 is reduced when it is removed. After the auxiliary support segment 330 acts as a support alignment structure in the early stage, it can also function as a retrieval hook at the end of the filter's recovery period.

[0058] In another embodiment, in order to make the auxiliary support 330 easier to be captured by the capture ring, the auxiliary connecting section 331 extends distally from the inside to the outside.

[0059] In another embodiment, only the support section 334 of the auxiliary support section 332 is degradable, and the distance from the end of the transition section 333 of the auxiliary support section 332 to the axis of symmetry of the filter 300 is less than 2 / 3 of the distance from the support section 334 to the axis of symmetry, thereby avoiding the transition section 33 from contacting the blood vessel wall or having an excessively large contact area, which would make it difficult to detach later.

[0060] In another embodiment, reference Figure 12-13 , Figure 12 This is a schematic diagram of the auxiliary support 340 in its initial implantation state in another embodiment of Embodiment 2 of the present invention. Figure 13This is a schematic diagram of the proximal position of the filter 300 in the recovery state in Embodiment 2 of the present invention. This embodiment includes an improved auxiliary support 340, which includes an auxiliary connecting section 341 fixedly connected to the proximal end 310, and an auxiliary support section 342 generally surrounding the auxiliary connecting section 341. If the proximal end 310 is misaligned, it requires a large supporting force to correct it to the center of the blood vessel. The rod-shaped auxiliary support section 342 is prone to damaging the blood vessel wall under excessive pressure, while the annular design of the auxiliary support section 342 can extend circumferentially along the blood vessel wall, distributing the stress that should be concentrated to multiple locations, thereby reducing the risk of blood vessel damage. Similarly, after the auxiliary support section 342 degrades, the auxiliary connecting section 341 can also function as a recovery hook.

[0061] In another embodiment, the auxiliary support section 342 extends axially to form a threaded structure, and the auxiliary support section 342 has a passivated free end, which avoids damage to the blood vessel wall, and the threaded structure can be straightened, thereby increasing the convenience of insertion into the sheath.

[0062] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A filter, characterized by, The filter includes a proximal end, a distal end, and a filtration section connecting the proximal end and the distal end. The proximal end of the filter is provided with an auxiliary support member that is at least partially degradable, which supports the proximal end near the middle of the implantation area after implantation.

2. The filter of claim 1, wherein, The auxiliary support includes an auxiliary connecting section fixedly connected to the proximal end and an auxiliary support section extending obliquely outward from the auxiliary connecting section.

3. The filter of claim 2, wherein, The auxiliary support section includes an inner transition section and an outer support section, the transition section and the support section extending in opposite directions in the axial direction.

4. The filter of claim 3, wherein, In a radially outward direction, the transition section extends obliquely toward the distal end, and the support section extends obliquely toward the proximal end.

5. The filter according to claim 2, characterized in that, The auxiliary support segment is degradable. At the initial implantation stage, the auxiliary support segment supports the proximal end of the filter. After the proximal end is stabilized, the auxiliary support segment gradually degrades.

6. The filter according to claim 2, characterized in that, The auxiliary connecting section extends distally from the inside to the outside.

7. The filter according to claim 3, characterized in that, The support section of the auxiliary support section is degradable, and the distance from the end of the transition section to the axis of symmetry of the filter is less than 2 / 3 of the distance from the support section to the axis of symmetry.

8. The filter according to claim 3, characterized in that, The auxiliary support includes an auxiliary connecting section fixedly connected to the proximal end, and an auxiliary support section surrounding the auxiliary connecting section.

9. The filter according to claim 8, characterized in that, The auxiliary support section extends axially to form a threaded structure.

10. The filter according to claim 9, characterized in that, The auxiliary support section has a passivated free end.

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