CN113229991A

CN113229991A - Anti-displacement vena cava filter

Info

Publication number: CN113229991A
Application number: CN202110598857.8A
Authority: CN
Inventors: 郑殿会; 刘颖
Original assignee: Beijing Huamai Taike Medical Instrument Co ltd
Current assignee: Beijing Huamai Taike Medical Instrument Co ltd
Priority date: 2021-05-31
Filing date: 2021-05-31
Publication date: 2021-08-10

Abstract

The invention provides a displacement-preventing vena cava filter, which relates to the field of medical instruments and comprises a covered stent, a filter main body and a recovery wire; the filter main body comprises a recovery rod, a sleeve and a plurality of filter arms; the recovery rod penetrates through the sleeve, and the part of the recovery rod, which is positioned in the sleeve, is connected to the inner wall of the sleeve through a spring; the near ends of the filtering arms are uniformly connected with the radial circumferential surface of the sleeve around the recovery rod; the far end of at least one filtering arm is provided with an anchoring ring, the near end of the recovery wire is connected with the far end of the recovery rod, and the far end of the recovery wire connects the anchoring ring with a film of the covered stent; in the released state: the spring is in a compressed state; in the event that the proximal end of the retrieval rod is subjected to an external force that is dragged proximally, the spring can be further compressed and the distal end of the retrieval wire can be disengaged from the anchoring ring. The invention solves the technical problems that the hemorrhages at the implanted part are easy to occur after the vena cava filter is released into the blood vessel, the implantation time of the filter is short, and the filter is difficult to be safely taken out in the prior art.

Description

Anti-displacement vena cava filter

Technical Field

The invention relates to the field of medical instruments, in particular to a displacement-preventing vena cava filter.

Background

At present, pulmonary embolism is prevented by implanting a vena cava filter into a lower cavity clinically. The vena cava filter is an instrument made of metal wires and is placed into the infrarenal veins through a special conveying device to intercept large thrombus in blood flow and avoid entering pulmonary artery along with the blood flow to cause lethal pulmonary embolism.

The existing vena cava filter mainly comprises a filtering arm consisting of a fixed arm and an anchoring arm and a recovery hook fixedly connected with the near end of the filtering arm, wherein the far end of the anchoring arm is provided with the anchoring hook, and the recovery hook is used for capturing the recovery hook in a blood vessel and then pulling out the blood vessel to realize the recovery of the filter after the filter is implanted into a human body for a period of time; the anchoring hook is of a barb structure, and the barb of the filter is inserted into the vein blood vessel wall to prevent the filter from being displaced after the filter is released in the blood vessel.

However, the existing vena cava filter has at least the following problems:

the anchoring hook is easy to stab or pierce the blood vessel due to the fact that the vein blood vessel is thin, so that the situation that the implanted part is bled is caused, the injury to the blood vessel is large, meanwhile, the barb anti-displacement structure pierces the blood vessel wall, the endothelium of the blood vessel is proliferated, the endothelial tissue can cover the vena cava filter gradually after a period of time, the filter and the blood vessel grow together, the filter is difficult to withdraw from the blood vessel, the contact area between the filter and the blood vessel tissue is larger, the contact time is longer, the filter is difficult to recover from the blood vessel, but the recovery time is too short, the time for the filter to act in the blood vessel is short, and the treatment effect is far not achieved; in addition, because the anchoring hook is punctured into the vessel wall, after the filter is withdrawn from the vessel, a large wound exists at the original contact part, the wound part has large damage to the vessel, and thrombus is easy to gather again;

in addition, after the vena cava filter is released in a blood vessel, the filter is easy to incline, the recovery hook is contacted with the blood vessel wall, the recovery hook is not easy to be caught by a recovery device, and recovery is difficult to realize.

In conclusion, in the prior art, the vena cava filter is easy to bleed at the implanted part after being released in the blood vessel, the implantation time of the filter is short, the filter is difficult to be taken out safely and the like.

Disclosure of Invention

The invention aims to provide a displacement-preventing vena cava filter, which aims to solve the technical problems that bleeding at an implanted part is easy to occur after the vena cava filter is released into a blood vessel, the filter is short in implantation time and difficult to safely take out in the prior art.

In order to achieve the above purpose, the embodiment of the invention adopts the following technical scheme:

the embodiment of the invention provides a displacement-preventing vena cava filter, which comprises a tectorial membrane bracket, a filter main body and a recovery wire;

the filter body comprises a recovery rod, a sleeve and a plurality of filter arms;

the recovery rod penetrates through the sleeve, the part of the recovery rod, which is positioned in the sleeve, is connected to the inner wall of the sleeve through a spring, and the extension direction of the spring extends along the length direction of the recovery rod; the near end of the recovery rod is provided with a hook part;

the proximal ends of the plurality of filter arms are uniformly connected to the radial circumferential surface of the sleeve around the recovery rod; the far end of at least one filtering arm is provided with an anchoring ring, the near end of the recovery wire is connected with the far end of the recovery rod, and the far end of the recovery wire connects the anchoring ring with the tectorial membrane of the tectorial membrane stent;

in the released state: the covered stent is expanded to be cylindrical, the far ends of the filtering arms are all opened towards the periphery, so that the filtering arms are expanded to be umbrella-shaped, and the springs are in a compressed state;

in the event that the proximal end of the retrieval rod is subjected to a proximally-trailing external force, the spring can be further compressed and the distal end of the retrieval wire can be disengaged from the anchoring ring.

In an alternative embodiment of this embodiment, a developer portion is provided on the stent graft, and a developer coating is applied to the filter arm provided with the anchoring ring.

In a further alternative embodiment, the developing portion includes a developing ring.

In an alternative embodiment of this embodiment, if the filter arm with the anchoring ring at the distal end of the filter arms is an anchoring arm, and the other filter arms of the filter arms are fixed arms, then: the anchoring arms include at least two.

In a further alternative embodiment, at least two of the anchoring arms are symmetrically disposed on either side of the central axis of the cannula.

In an alternative embodiment of this embodiment, the anchoring arm has a length greater than the length of the securing arm, and the anchoring ring is provided at a location where the distal end of the anchoring arm is longer than the securing arm.

In an optional implementation manner of this embodiment, the distal end surfaces of the plurality of filter arms are all cambered surfaces.

In an optional implementation manner of this embodiment, the distal end of the recovery rod is provided with an end ring or a threading hole, and the proximal end of the recovery thread is connected to the end ring or the threading hole; and/or a hook is arranged at the near end of the recovery rod and forms the hook part. Where "and/or" means that the preceding structure and/or "preceding structure are provided simultaneously or alternatively to the" and/or "following structure.

In an optional implementation manner of this embodiment, the covered stent includes a covering membrane and a bare stent, the bare stent includes a plurality of stent rings, and the stent rings are connected to the covering membrane in a spaced arrangement from a distal end of the covering membrane to a proximal end of the covering membrane.

In a further alternative embodiment, the stent ring is formed by a plurality of V-shaped stent units connected end-to-end.

The embodiment of the invention can realize the following beneficial effects:

the embodiment of the invention provides a displacement-preventing vena cava filter, which comprises a tectorial membrane bracket, a filter main body and a recovery line. Specifically, the filter body includes a recovery rod, a sleeve, and a plurality of filter arms. The recovery rod penetrates through the sleeve, the part of the recovery rod, which is positioned in the sleeve, is connected to the inner wall of the sleeve through a spring, and the extension direction of the spring extends along the length direction of the recovery rod; the near end of the recovery rod is provided with a hook part. The near ends of the filtering arms are uniformly connected to the radial circumferential surface of the sleeve around the recovery rod; the far end of at least one filtering arm is provided with an anchoring ring, the near end of the recovery wire is connected with the far end of the recovery rod, and the far end of the recovery wire connects the anchoring ring with the tectorial membrane of the tectorial membrane stent. In the released state: the tectorial membrane support struts and is cylindricly, and the distal end of many filter arms all opens all around to make many filter arms strut and be umbelliform, the spring is in by compressed state. In the event that the proximal end of the retrieval rod is subjected to an external force that is dragged proximally, the spring can be further compressed and the distal end of the retrieval wire can be disengaged from the anchoring ring.

The embodiment solves the problems that the vena cava filter is easy to bleed at the implanted part after being released in the blood vessel, the filter is short in implantation time and difficult to safely take out in the prior art on the basis of avoiding the vena cava filter from being released in the blood vessel and then shifting the filter.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic view of the overall structure of a stent graft in an anti-displacement vena cava filter according to an embodiment of the present invention;

FIG. 2 is a schematic view of the overall structure of a filter body in an anti-displacement vena cava filter according to an embodiment of the present invention from one perspective;

FIG. 3 is a schematic view of the overall structure of the filter body in another view angle of the anti-displacement vena cava filter according to an embodiment of the present invention;

fig. 4 is an overall configuration view of a filter main body in the anti-displacement vena cava filter provided by the embodiment of the invention, as viewed from the proximal end to the distal end;

FIG. 5 is a schematic view of the overall structure of the anti-migration vena cava filter in a released state according to the embodiment of the present invention;

FIG. 6 is an enlarged view of a portion A of FIG. 5;

fig. 7 is a schematic view of a connection structure of a recovery rod connected to a cannula through a spring in a vena cava filter according to an embodiment of the present invention.

Icon: 100-covered stent; 110-a scaffold ring; 120-film covering; 200-a filter body; 210-a recovery rod; 211-end ring; 212-a hook portion; 220-a cannula; 230-a filter arm; 231-anchoring arms; 2311-anchoring the ring; 232-fixed arm; 240-spring; 300-recycling line.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "upper", "lower", "proximal", "distal", "inner", "outer", and the like refer to orientations or positional relationships based on those shown in the drawings or orientations or positional relationships that are conventionally used to place products of the present invention, and are used for convenience of description and simplicity of description, but do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

In particular, in the present invention, the term "proximal" refers to the end closer to the human heart during surgery, and "distal" refers to the end opposite the "proximal".

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," and "connected" are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Some embodiments of the invention are described in detail below with reference to the accompanying drawings. The embodiments described below and the features of the embodiments can be combined with each other without conflict.

The present embodiment provides a displacement prevention vena cava filter, which comprises a stent graft 100, a filter body 200, and a recovery wire 300, referring to fig. 1 to 7. Specifically, the filter body 200 includes a recovery rod 210, a sleeve 220, and a plurality of filter arms 230. The recovery rod 210 penetrates the casing 220, a portion of the recovery rod 210 located inside the casing 220 is connected to an inner wall of the casing 220 through a spring 240, and a stretching direction of the spring 240 extends along a length direction of the recovery rod 210, specifically, but not limited to, as shown in fig. 7, a limiting boss is provided on a portion of the recovery rod 210 located inside the casing 220, the spring 240 is sleeved on the recovery rod 210, a distal end of the spring 240 is fixed or abutted to the limiting boss, and a proximal end of the spring 240 is fixed or abutted to an inner wall of a proximal end of the casing 220. The proximal end of the recovery rod 210 is provided with a hooking portion 212, and the hooking portion 212 includes, but is not limited to, a hook structure, a loop-shaped hook structure, or the like. The proximal ends of the plurality of filter arms 230 are uniformly connected to the radial circumferential surface of the sleeve 220 around the recovery rod 210; the distal end of at least one of the filter arms 230 is provided with an anchoring ring 2311, the proximal end of the retrieval line 300 is connected to the distal end of the retrieval rod 210, and the distal end of the retrieval line 300 connects the anchoring ring 2311 to the stent graft 120 of the stent graft 100; specific connection ways of the proximal ends of the recovery threads 300 to the distal end of the recovery rod 210 are various, for example, but not limited to, as shown in fig. 2 and 3, the distal end of the recovery rod 210 is provided with an end ring 211, and the proximal ends of the recovery threads 300 are connected to the end ring 211, or, the distal end of the recovery rod 210 is provided with a threading hole, and the proximal ends of the recovery threads 300 are connected to the threading hole, etc.

In the released state: the stent graft 100 is expanded into a cylindrical shape, and the distal ends of the plurality of filter arms 230 are all opened towards the periphery, so that the plurality of filter arms 230 are expanded into an umbrella shape, and the spring 240 is in a compressed state; in case the proximal end of the recovery rod 210 receives an external force dragged in the proximal direction, the spring 240 can be further compressed and the distal end of the recovery wire 300 can be disengaged from the anchoring ring 2311.

Before thrombus treatment: implanting the anti-displacement vena cava filter into the position of the intravascular thrombus filter by using an implantation device, releasing the covered stent 100 and the filter main body 200, expanding the covered stent 100 into a cylindrical shape to be supported on the inner wall of the blood vessel, expanding the plurality of filter arms 230 into an umbrella shape, compressing the spring 240, and enabling the recovery rod 210 to be closer to the far end under the restoring force of the spring 240; then, a plurality of filtering arms 230 are used for filtering larger venous thrombus to prevent pulmonary embolism; after the treatment is completed, the filter body 200 is recovered from the blood vessel, specifically, the recovery rod 210 is pulled towards the proximal direction by the hook 212 at the proximal end of the recovery rod 210, the spring 240 is further compressed, the recovery rod 210 moves towards the proximal direction relative to the sleeve 220, the distal end of the recovery rod 210 drives the recovery wire 300 to withdraw towards the proximal direction, so that the distal end of the recovery wire 300 is separated from the anchoring ring 2311, further, the filter arm 230 is separated from the covering membrane 120, the recovery rod 210 is continuously withdrawn, so as to further withdraw the filter body 200 containing the filtered thrombus out of the blood vessel, and the covered stent 100 is permanently placed in the body, wherein the covering membrane 120 may be a fabric covering membrane or a polymer covering membrane, and the like, preferably but not limited to a polymer covering membrane with better adaptability to the human body, so as to reduce or avoid the immunological rejection reaction of the human body to the covering membrane 120.

Compared with the direct anchoring of the filtering arm 230 to the blood vessel wall, the anti-displacement vena cava filter provided by the embodiment can achieve at least the following advantages:

(1) after release, the stent graft 100 is expanded into a cylindrical shape to be supported on the inner wall of the blood vessel, has good supporting and displacement preventing effects and can avoid the displacement of a filter;

(2) the covered stent 100 is opened to be cylindrical, the implantation of the covered stent 100 has no damage to the blood vessel, and after the anti-displacement vena cava filter is completely released, the filter main body 200 is not in direct contact with the blood vessel wall, so that the blood vessel can be prevented from being punctured or punctured after the filter is implanted, and the problem that the implanted part of the vena cava filter bleeds after being released in the blood vessel in the prior art is solved;

(3) after the anti-displacement vena cava filter is completely released, the anti-displacement vena cava filter is not contacted with the filter main body 200 in the vascular endothelial hyperplasia process, and the filter main body 200 can still be pulled out from the covered stent 100 after being implanted for a long time, so that the taking-out time of the filter main body 200 is prolonged, the recovery time is long enough, the filter main body 200 can filter large thrombus in a human body for a longer time, and the problem of short implantation time of the filter after the vena cava filter is released in a blood vessel in the prior art is solved;

(4) after the anti-displacement vena cava filter is completely released, the blood vessel wall is not contacted with the filter main body 200, so that the blood vessel is not pulled when the filter main body 200 is withdrawn, the filter main body 200 is easy to withdraw, and the blood vessel is not damaged in the process of withdrawing the filter main body 200;

(5) after the anti-displacement vena cava filter is completely released, the contact area between the filter main body 200 and the covered stent 100 is large, and the filtering arm 230 of the filter main body 200 is supported on the covered stent 100, so that the filter main body 200 can be prevented from inclining, further the filter main body 200 can be kept in a filtering posture constantly, the near end of the recovery rod 210 can be caught, the filter main body 200 can be retracted, and the blood vessel can not be damaged in the process of retracting the filter main body 200;

(6) in this embodiment, the filter arms 230 of the filter main body 200 are fixed to the stent graft 100 such that the end rings 211 at the distal ends of the plurality of filter arms 230 of the filter main body 200 are fixed to the stent graft 120 of the stent graft 100 by the retrieval wire 300 and the retrieval wire 300 can be detached from the stent graft 120 of the stent graft 100 when the proximal end of the retrieval rod 210 receives an external force pulling in the proximal direction, and therefore, the filter main body 200 is retracted without damaging the blood vessel and without cutting the stent graft 120 of the stent graft 100 over a large area, and the blood flow in the blood vessel is effectively prevented from being blocked by the cut stent graft 120.

In conclusion, the embodiment solves the problems that the hemorrhaging of the implanted part is easy to occur after the vena cava filter is released in the blood vessel, the filter implantation time is short, and the filter is difficult to safely take out in the prior art on the basis of avoiding the vena cava filter from being released in the blood vessel and then the filter is displaced.

Further, to ensure the accuracy of the implantation position of the anti-migration vena cava filter, in an alternative embodiment of the present embodiment, a developing ring or other developing part is provided on the stent graft 100, a developing coating is provided on the filter arm 230 provided with the anchoring ring 2311, and the specific implantation position is determined by the developing part and the developing coating, so as to achieve a good thrombus filtering effect.

Further, with continued reference to fig. 1 to 6, in the present embodiment, the filter arm 230 provided with the anchoring ring 2311 at the distal end of the filter arms 230 is taken as an anchoring arm 231, and the other filter arms 230 of the filter arms 230 are taken as fixing arms 232, so that: the anchoring arms 231 comprise at least two anchoring arms 231, and at least two anchoring arms 231 of the anchoring arms 231 are symmetrically arranged at two sides of the central axis of the sleeve 220 so as to ensure the position stability of the anti-displacement vena cava filter relative to the blood vessel after the anti-displacement vena cava filter is implanted into the blood vessel.

Preferably, the length of the anchoring arm 231 is greater than the length of the fixing arm 232, and the anchoring ring 2311 is provided at a portion where the distal end of the anchoring arm 231 is longer than the fixing arm 232.

In addition, in order to avoid the anchoring arm 231 and the fixing arm 232 from scratching blood vessels during implantation or withdrawal, in an alternative embodiment of the present embodiment, the distal end surfaces of the plurality of filtering arms 230 are preferably all curved surfaces, preferably hemispherical surfaces.

In this embodiment, the covered stent 100 includes a covered membrane 120 and a bare stent, and more preferably, as shown in fig. 1, 5 and 6, the bare stent includes a plurality of stent rings 110, the stent rings 110 are connected to the covered membrane 120 from the distal end of the covered membrane 120 to the proximal end of the covered membrane 120 in a pairwise spaced arrangement, and the arrangement of the stent rings 110 increases the adherence of the covered membrane 120, so as to prevent large thrombi from leaking out from between the covered membrane 120 and the blood vessel wall, and improve the effectiveness of the thrombi filtration. To increase the supporting force of the stent ring 110, it is preferable that the stent ring 110 is formed by connecting a plurality of V-shaped stent units end to end.

In this embodiment, the covering membrane 120 may be connected to the inner side of the bare stent or the outer side of the bare stent, and preferably, the bare stent is connected to the outer side of the covering membrane 120 to increase the anti-displacement function of the anti-displacement vena cava filter, and meanwhile, the compliance of the bare stent is improved, and the specific connection manner of the bare stent and the covering membrane 120 includes, but is not limited to, sewing the bare stent to the covering membrane 120.

In this embodiment, the entire filter body 200 is preferably made of steel or other metal.

Finally, it should be noted that: the embodiments in the present description are all described in a progressive manner, each embodiment focuses on the differences from the other embodiments, and the same and similar parts among the embodiments can be referred to each other; the above embodiments in the present specification are only used for illustrating the technical solutions of the present invention, and not for limiting the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An anti-displacement vena cava filter, which is characterized by comprising a covered stent (100), a filter main body (200) and a recovery wire (300);

the filter body (200) comprises a retrieval rod (210), a sleeve (220), and a plurality of filter arms (230);

the recovery rod (210) penetrates through the sleeve (220), the part of the recovery rod (210) located inside the sleeve (220) is connected to the inner wall of the sleeve (220) through a spring (240), and the extension and retraction direction of the spring (240) extends along the length direction of the recovery rod (210); the near end of the recovery rod (210) is provided with a hook part (212);

the proximal ends of the filter arms (230) are uniformly connected to the radial circumferential surface of the sleeve (220) around the recovery rod (210); the far end of at least one filtering arm (230) is provided with an anchoring circular ring (2311), the near end of the recovery wire (300) is connected with the far end of the recovery rod (210), and the far end of the recovery wire (300) connects the anchoring circular ring (2311) with the tectorial membrane (120) of the tectorial membrane bracket (100);

in the released state: the covered stent (100) is unfolded into a cylindrical shape, the far ends of the filtering arms (230) are all opened towards the periphery, so that the filtering arms (230) are unfolded into an umbrella shape, and the spring (240) is in a compressed state;

in case the proximal end of the retrieval rod (210) is subjected to an external force dragging proximally, the spring (240) can be further compressed and the distal end of the retrieval wire (300) can be disengaged from the anchoring ring (2311).

2. The anti-migration vena cava filter according to claim 1, wherein a visualization portion is provided on the stent graft (100) and a visualization coating is applied to the filter arms (230) provided with the anchoring rings (2311).

3. The anti-migration vena cava filter according to claim 2, wherein the visualization portion comprises a visualization ring.

4. The anti-migration vena cava filter according to claim 1,

taking the filter arm (230) with the anchoring ring (2311) at the distal end of the filter arm (230) as an anchoring arm (231), and taking the other filter arms (230) in the filter arm (230) as fixing arms (232), then:

the anchoring arms (231) comprise at least two.

5. The anti-migration vena cava filter according to claim 4, wherein at least two of the anchoring arms (231) are symmetrically disposed on either side of a central axis of the cannula (220).

6. The anti-migration vena cava filter according to claim 4, wherein the length of the anchoring arm (231) is greater than the length of the securing arm (232), and the anchoring ring (2311) is provided at a location where the distal end of the anchoring arm (231) is longer than the securing arm (232).

7. The anti-migration vena cava filter according to claim 1, wherein the distal end faces of the plurality of filter arms (230) are all curved.

8. The anti-migration vena cava filter according to claim 1,

the far end of the recovery rod (210) is provided with an end circular ring (211) or a threading hole, and the near end of the recovery thread (300) is connected with the end circular ring (211) or the threading hole;

and/or the proximal end of the recovery rod (210) is provided with a hook, and the hook forms the hook part (212).

9. The anti-migration vena cava filter according to claim 1, wherein the covered stent (100) comprises a covered membrane (120) and a bare stent, the bare stent comprises a plurality of stent rings (110), and the stent rings (110) are connected to the covered membrane (120) in a two-by-two spaced arrangement from the distal end of the covered membrane (120) to the proximal end of the covered membrane (120).

10. The anti-migration vena cava filter according to claim 9, wherein the stent ring (110) is formed from a plurality of V-shaped stent units connected end-to-end.