CN116712213B

CN116712213B - Combined vena cava filter

Info

Publication number: CN116712213B
Application number: CN202310968834.0A
Authority: CN
Inventors: 郑殿会; 张玉龙; 李会钗
Original assignee: Beijing Xinyou Medical Technology Co ltd
Current assignee: Beijing Xinyou Medical Technology Co ltd
Priority date: 2023-08-03
Filing date: 2023-08-03
Publication date: 2024-01-19
Anticipated expiration: 2043-08-03
Also published as: CN116712213A

Abstract

The invention provides a combined vena cava filter, which relates to the field of medical appliances, and comprises a back filter and a front filter; the back filter and the front filter respectively comprise respective recovery hooks and a plurality of filter arms which are connected with the recovery hooks at intervals in the circumferential direction and extend towards the same side of the recovery hooks; the free ends of all or part of the filter arms of the back filter are provided with anchoring hooks; in the implantation state, the back filter and the front filter are arranged oppositely, the free ends of at least two filter arms of the back filter are correspondingly spliced or clamped at the free ends of at least two filter arms of the front filter, and the anchoring hooks of the back filter are anchored at the inner wall of a blood vessel; in the recovered state, the post-filter was withdrawn backward and the pre-filter was withdrawn forward, respectively. The invention relieves the technical problems that the vena cava filter in the prior art is easy to incline, hurt the vessel wall and can not be taken out or not be taken out easily.

Description

Combined vena cava filter

Technical Field

The invention relates to the technical field of medical instruments, in particular to a combined vena cava filter.

Background

In the mechanical thrombus taking process, the vena cava filter can capture the reconstruction of the critical thrombus and protect the deep venous blood flow, in particular, the vena cava filter is implanted into the inferior vena cava through skin, can capture the thrombus which falls off in the venous system, is used for treating the deep venous thrombosis of the lower limb by combining an operation, a medicine or an intervention method, can reduce the incidence rate of the critical pulmonary arterial embolism, keeps the deep vein unblocked, and plays an indispensable role in treating DVT (deep vein thrombosis) and preventing PE (pulmonary arterial embolism).

The use of vena cava filters has had positive efficacy in the treatment of most patients, and healthcare workers have also found problems, mainly including:

(1) After endothelialization of the spindle-shaped vena cava filter and the vessel wall, the vena cava filter cannot be retrieved;

(2) The umbrella-shaped vena cava filter is easy to incline when released, thereby damaging the vessel wall and being difficult to take out.

Disclosure of Invention

The invention aims to provide a combined vena cava filter, which is used for alleviating the technical problems in the prior art.

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

the embodiment of the invention provides a combined venous filter, which comprises a back filter and a front filter. The back filter and the front filter respectively comprise respective recovery hooks and a plurality of filter arms which are connected to the recovery hooks at intervals in the circumferential direction and extend towards the same side of the recovery hooks; an anchoring hook is arranged at the free end of all or part of the filter arms of the back filter; in an implantation state, the back filter and the front filter are arranged oppositely, the free ends of at least two filter arms of the back filter are spliced or clamped at the free ends of at least two filter arms of the front filter in a one-to-one correspondence manner, and the anchoring hooks of the back filter are anchored on the inner wall of a blood vessel; in the recovered state, the post-filter and the pre-filter are withdrawn backward and forward, respectively.

In an alternative implementation manner of this embodiment, it is preferable that a filter arm of the back filter that is inserted or clamped with a filter arm of the front filter is used as a back main anchor arm:

the recovery hook of the back filter comprises a back shell, a back recovery rod and a spring, wherein the back recovery rod penetrates through the back shell and is connected with the back shell through the spring, a connecting part is arranged at the position, located outside the back shell, of the back recovery rod, and the connecting part is used for being temporarily connected with a recoverer;

each rear main anchor arm comprises a main arm and an anchor arm respectively; a main arm cavity penetrating through the main arm along the extending direction of the main arm is arranged in the main arm, and a main arm cutting groove communicated with the main arm cavity is arranged on the peripheral wall of the free end of the main arm; the anchoring arm penetrates through the main arm cavity, and the free end of the anchoring arm is provided with the anchoring hook which is elastically bent outwards in the radial direction; one end of the main arm is fixedly connected to the rear shell and is communicated with the inner cavity of the rear shell, and one end of the anchoring arm is connected to the rear recovery rod;

the spring is configured to push the anchoring arm in a free state relative to the main arm in a free direction of the main arm so that the anchoring hook extends out of the main arm slot, and to elastically deform under the condition that the external force pulls the rear recovery rod in an external direction of the rear housing through the recovery device so as to pull the anchoring arm back in a direction of the rear housing relative to the main arm, and further to enable the anchoring hook to be elastically deformed and accommodated in the main arm cavity.

Further preferably, the recovery hook of the back filter further comprises a back baffle; the rear baffle and the spring are both arranged in the inner cavity of the rear shell, and the rear baffle is circumferentially limited in the rear shell so that the rear baffle can slide back and forth in the rear shell but cannot rotate circumferentially; the rear baffle plate is sleeved and connected with the outer peripheral wall of the rear recovery rod in a threaded mode, and the spring is arranged between the rear baffle plate and the inner wall surface of the rear shell.

In an alternative implementation manner of this embodiment, it is preferable that a filter arm of the front filter and a filter arm of the rear filter are inserted or clamped with each other as a front main anchor arm; the free end of the front main anchor arm is provided with an inserting cavity extending along the extending direction of the front main anchor arm, and the side wall of the free end of the front main anchor arm is provided with an avoidance cutting groove. In an implantation state, the free end of the main arm in the back filter is inserted into the insertion cavity of the free end of the front main anchor arm in the front filter, and the anchor hook of the free end of the anchor arm in the back filter passes through the avoidance cutting groove.

Further preferably, the socket extends to a free end of the front main anchor arm, and the socket includes a diameter-changing portion having a diameter gradually increasing from the free end of the front main anchor arm toward the recovery hook of the front strainer.

Preferably, the socket cavity penetrates the front main anchor arm along the extending direction of the front main anchor arm.

In an alternative implementation manner of this embodiment, more preferably, the filter arm of the back filter includes at least two back main anchor arms and at least two back auxiliary arms, and the back main anchor arms and the back auxiliary arms are staggered with each other along the circumferential direction of the recovery hook of the back filter; the filter arm of the front filter comprises at least two front main anchor arms and at least two front auxiliary arms, and the front main anchor arms and the front auxiliary arms are distributed in a staggered manner along the circumferential direction of the recovery hook of the front filter. In an implantation state, the free ends of the rear main anchor arms are correspondingly spliced or clamped with the free ends of the front main anchor arms one by one; all the rear auxiliary arms are opened to be supported on the inner wall of the blood vessel in a half-fusiform manner, and all the front auxiliary arms are opened to be supported on the inner wall of the blood vessel in a half-fusiform manner.

More preferably, the recovery hook of the front filter includes a front housing and a front recovery lever; the front recovery rod passes through and is fixed on the front shell; one end of all filter arms of the front filter are fixedly connected to the front shell respectively; the implantation state is as follows: the free end of the front recovery rod and the free end of the rear recovery rod are mutually spliced.

More preferably, the filter arm of the back filter, which is inserted into or clamped with the filter arm of the front filter, is taken as a back main anchor arm, the filter arm of the front filter, which is inserted into or clamped with the filter arm of the back filter, is taken as a front main anchor arm, and in the implanted state, a side surface of the free end of the main arm of the back main anchor arm, which is in contact with the free end of the front main anchor arm, is taken as a first side surface, and a side surface of the free end of the front main anchor arm, which is in contact with the free end of the main arm of the back main anchor arm, is taken as a second side surface, wherein:

the first side surface is provided with a plurality of first arc-shaped buckling bulges, the second side surface is provided with a plurality of second arc-shaped buckling bulges, and the first arc-shaped buckling bulges and the second arc-shaped buckling bulges are in staggered snap fit under the implantation state.

In the embodiments of the present invention, "and/or" means "and/or" the structure described before and "and/or" the structure described after are simultaneously or alternatively arranged, preferably "and/or" the structure described before and "the structure described after are simultaneously arranged.

The embodiment of the invention relieves the technical problems that (1) the fusiform vena cava filter and the vascular wall are endothelialized and then the vena cava filter cannot be retrieved and (2) the umbrella-shaped vena cava filter is easy to incline when released, thereby damaging the vascular wall and being difficult to take out in the prior art, and the specific use method and the beneficial effects can be achieved are described in the detailed description section of the specification.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of the overall structure of a post-filter according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of the post-filter shown in FIG. 1;

FIG. 3 is an enlarged view of a part of the portion A11 in FIG. 2;

FIG. 4 is an enlarged view of a portion of the structure at the portion A12 in FIG. 2;

FIG. 5 is a distribution diagram of the filter arms of the post-filter of FIG. 1 in the circumferential direction of the recovery hooks;

FIG. 6 is a schematic view showing an implantation state of a post-filter according to an embodiment of the present invention;

FIG. 7 is an enlarged view of a portion of the structure at the portion A2 in FIG. 6;

FIG. 8 is a schematic view showing a recovery state of the post-filter according to the embodiment of the present invention;

FIG. 9 is an enlarged view of a portion of the structure at the portion A3 in FIG. 8;

FIG. 10 is a schematic view showing the overall structure of a front filter in a combined vena cava filter according to the embodiment of the invention;

FIG. 11 is a cross-sectional view of the pre-filter shown in FIG. 10;

FIG. 12 is an enlarged view of a part of the structure of the portion A41 in FIG. 11;

FIG. 13 is an enlarged view of a portion of the structure at the portion A42 in FIG. 11;

FIG. 14 is a distribution diagram of the filter arms of the pre-filter of FIG. 10 in the circumferential direction of the recovery hooks;

fig. 15 is a sectional view showing a combination state of a combination vena cava filter according to an embodiment of the invention;

FIG. 16 is an enlarged view of a portion of the structure at the portion A5 in FIG. 15;

FIG. 17 is a graph showing the profile of each filter arm in the peripheral direction of the recovery hooks in the combined vena cava filter of FIG. 15;

FIG. 18 is a schematic view showing an implantation state of a combined vena cava filter according to an embodiment of the invention;

FIG. 19 is an enlarged view of a portion of the structure at the A6 position in FIG. 18;

FIG. 20 is a schematic view showing a first state of recovery of a combined vena cava filter according to an embodiment of the invention;

FIG. 21 is an enlarged view of a portion of the structure at the portion A7 in FIG. 20;

FIG. 22 is a schematic view showing a second state of recovery of the combined vena cava filter according to the embodiment of the invention;

fig. 23 is a schematic view showing a third state of recovery of the combined vena cava filter according to the embodiment of the invention.

Icon: 100-post-filter; 1-a post-recovery hook; 11-a rear housing; 12-post recovery rod; 1201-rear hook; 1202-a posterior radial bulge; 13-a spring; 14-a tailgate; 2-post-filter arms; 21-a rear main anchor arm; 211-main arm; 2110-first arc snap projections; 2111-main arm lumen; 2112-main arm slot; 212-anchoring arms; 2121-anchoring hooks; 22-a rear auxiliary arm; 200-prefilter; 3-front recovery hooks; 31-a front housing; 32-front recovery bar; 3201—front hook; 3202-anterior radial bulge; 33-front baffle; 4-a pre-filter arm; 41-front main anchor arm; 410-a second arc-shaped snap-fit protrusion; 4101—an insertion cavity; 41011-diameter-variable portion; 4102-back-off slots; 42-a front auxiliary arm; 300-inferior vena cava; b1-a main anchor point; b2-auxiliary anchor point.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. The components of the 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 invention, as 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 made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that: like reference numerals and letters designate like items in the drawings, and thus once an item is defined in one drawing, no further definition or explanation thereof is necessary in the subsequent drawings.

In the description of the present invention, it should be noted that, directions or positional relationships indicated by terms such as "front end", "rear end", "inner", "outer", etc., are directions or positional relationships based on those shown in the drawings, or those that are conventionally put in place when the inventive product is used, are merely for convenience of describing the present invention and simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific direction, be configured and operated in a specific direction, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.

In the description of the present invention, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

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

Example 1

The present embodiment provides a combined vena cava filter, which includes a posterior filter 100 and an anterior filter 200, with reference to fig. 15 to 17. The back filter 100 and the front filter 200 each include a respective recovery hook and a plurality of filter arms connected to the recovery hook at circumferentially spaced intervals and extending toward the same side of the recovery hook; an anchor hook 2121 is provided at the free end of all or part of the filter arms of the posterior filter 100; in the implanted state, the posterior filter 100 and the anterior filter 200 are arranged opposite to each other, and the free ends of at least two filter arms of the posterior filter 100 are correspondingly inserted or clamped at the free ends of at least two filter arms of the anterior filter 200, and the anchoring hooks 2121 of the posterior filter 100 are anchored at the inner wall of the blood vessel; in the recovered state, the post-filter 100 is withdrawn backward and the pre-filter 200 is withdrawn forward, respectively.

Specifically, referring to fig. 18 and 19, taking an example of applying the combined vena cava filter to the inferior vena cava 300, the combined vena cava filter is in an initial state of "the back filter 100 is disposed opposite to the front filter 200, and the free ends of at least two filter arms of the back filter 100 are inserted or clamped to the free ends of at least two filter arms of the front filter 200 in one-to-one correspondence", and is installed in a vena cava filter delivery system, the vena cava filter delivery system with the combined vena cava filter is implanted into the inferior vena cava 300 through the femoral vein or the jugular vein by a puncturing method, and the vena cava filter delivery system is operated to release the combined vena cava filter and retrieve the vena cava filter delivery system. The combined vena cava filter is released as shown in fig. 18 and 19, and in combination with fig. 15, the blood flow direction sequentially flows through the posterior filter 100 and the anterior filter 200 from the upstream to the downstream; at this time, the anchor hook 2121 of the posterior filter 100 is anchored to the inner wall of the blood vessel as the main anchor point B1; the blood, when flowing through the respective filter arms of the posterior filter 100 and the respective filter arms of the anterior filter 200, is hung on the respective filter arms that are opened, and is intercepted in the central area of the anterior filter 200 after the filter arms are opened, to function as a filter plug;

when it is required to withdraw (recover) the combined vena cava filter, first, referring to fig. 20 to 21, a vena cava retriever is implanted from the femoral vein or the jugular vein into the inferior vena cava 300 by puncturing, the retriever is temporarily connected to a retrieving hook of the posterior filter 100, the retriever is manipulated to elastically deform an anchoring hook 2121 of the posterior filter 100 to withdraw the inner wall of the blood vessel, and referring to fig. 22, the retriever is continuously operated to withdraw the posterior filter 100, to disengage the posterior filter 100 from the anterior filter 200 until the posterior filter 100 is withdrawn; then, referring to fig. 23, the vena cava retriever is implanted from the jugular vein into the inferior vena cava 300 by puncturing, the retriever is temporarily connected to the retrieving hook of the anterior filter 200, the anterior filter 200 is pulled in the anterior direction of the anterior filter 200 to separate the anterior filter 200 from the vessel wall, the anterior filter 200 is pulled in the anterior direction of the anterior filter 200, and the anterior filter 200 is taken out through the jugular vein.

The filter after the implantation of the combined vena cava filter integrally comprises two parts which are in butt joint, and has the advantages of good neutrality, multiple attachment points, firm wall grasping, good adherence, stable and reliable implantation state, no limitation of the taking-out process to a large volume, convenient disassembly and easy taking-out. The two technical problems that (1) after the fusiform vena cava filter and the vascular wall are endothelialized, the vena cava filter cannot be retrieved and (2) the umbrella-shaped vena cava filter is easy to incline when released, thereby damaging the vascular wall and being difficult to take out in the prior art can be relieved simultaneously.

Specifically: as shown in fig. 1 to 9, the back filter 100 includes a back recovery hook 1 and a plurality of back filter arms 2, one end of each back filter arm 2 is connected to the back recovery hook 1, and the free ends of all or part of the back filter arms 2 are provided with anchor hooks 2121, respectively; as shown in fig. 10 to 16, the front filter 200 includes front recovery hooks 3 and front filter arms 4, and one end of each front filter arm 4 is connected to the front recovery hook 3, respectively. The free ends of the at least two back filter arms 2 are spliced or clamped with the free ends of the at least two front filter arms 4 in a one-to-one correspondence, and the back filter arms 2 and the front filter arms 4 which are spliced or clamped with each other at the end parts are respectively used as a back main anchor arm 21 and a front main anchor arm 41:

in this embodiment, preferably, as shown in fig. 1 to 9, the rear recovery hook 1 includes a rear housing 11, a rear recovery lever 12, and a spring 13, the rear recovery lever 12 passes through the rear housing 11 and is connected to the rear housing 11 by the spring 13, and a portion of the rear recovery lever 12 located outside the rear housing 11 is provided with a connection portion for temporary connection with the recoverer, and the connection portion may be a hook-shaped rear hooking portion 1201 as shown in fig. 4, or a screw structure or a ring structure provided with external threads, etc. Preferably, but not limited to, a blocking portion is further provided at a portion of the rear recovery rod 12 located outside the rear housing 11, and the blocking portion is configured to block the portion of the rear recovery rod 12 located outside the rear housing 11 from sliding into the rear housing 11, and preferably, but not limited to, as shown in fig. 4, the blocking portion is a rear radial bulge 1202 provided on the rear recovery rod 12 located outside the rear housing 11, and an outer diameter of the rear radial bulge 1202 is larger than a hole diameter of the recovery rod perforation on the rear housing 11 to limit the rear recovery rod 12 relative to the rear housing 11.

As shown in fig. 2 and 3, each rear main anchor arm 21 includes a respective main arm 211 and anchor arm 212; a main arm chamber 2111 penetrating the main arm 211 in the extending direction of the main arm 211 is provided in the main arm 211, and a main arm slit 2112 communicating with the main arm chamber 2111 is provided in the peripheral wall of the free end of the main arm 211; the anchor arm 212 passes through the main arm cavity 2111 and the free end of the anchor arm 212 is provided with an anchor hook 2121 which is resiliently bent radially outwardly, the whole of the anchor arm 212 preferably but not limited to being prefabricated from a pinch titanium alloy or other memory metal which gives it a free state in a bent shape with the anchor hook 2121. Referring to fig. 4, one end of the main arm 211 is fixedly connected to the rear housing 11 and communicates with the inner cavity of the rear housing 11, and one end of the anchor arm 212 is connected to the rear recovery lever 12. The spring 13 is configured to be capable of pushing the anchor arm 212 in a free state with respect to the main arm 211 in a free end direction of the main arm 211 so that the anchor hook 2121 protrudes out of the main arm notch 2112, and to be elastically deformed when the recovery lever 12 is pulled in an external direction of the rear housing 11 by an external force through the recovery device so as to pull the anchor arm 212 back in a direction of the rear housing 11 with respect to the main arm 211, thereby elastically deforming and accommodating the anchor hook 2121 in the main arm cavity 2111.

The rear recovery hook 1 preferably includes a rear baffle 14 for easy operation, for example, by pushing an outer tube against the rear housing 11 using a multi-tube type recoverer, temporarily connecting a front end of the inner tube with a connection portion of the rear recovery rod 12, and withdrawing the inner tube with respect to the outer tube; the rear baffle 14 and the spring 13 are arranged in the inner cavity of the rear shell 11, and the rear baffle 14 is circumferentially limited in the rear shell 11 through a baffle strip or a bulge or other structures arranged in the rear shell 11, so that the rear baffle 14 can slide back and forth in the rear shell 11 but cannot rotate circumferentially; the rear baffle 14 is sleeved and screwed on the outer peripheral wall of the rear recovery rod 12, and the spring 13 is arranged between the rear baffle 14 and the inner wall surface of the rear housing 11.

When the back filter 100 and the front filter 200 are oppositely implanted in the blood vessel in opposite directions, all the back main anchor arms 21 are opened, and the anchor hooks 2121 extend out of the main arm slots 2112 at the free ends of the main arms 211 to be anchored on the inner wall of the blood vessel under the elastic force of the springs 13; all front main anchor arms 41 are opened, and the free ends of main arms 211 in rear main anchor arms 21 of rear filter 100 are mutually spliced or clamped with the free ends of front main anchor arms 41 of front filter 200;

when the back filter 100 is recovered, the back baffle 14 slides backwards along the inner wall of the back shell 11 against the elastic force of the spring 13 by rotating the back recovery rod 12 relative to the back shell 11 of the back recovery hook 1, and the anchoring arm 212 slides backwards relative to the main arm 211 until the anchoring hook 2121 elastically deforms to withdraw from the inner wall of the blood vessel and is accommodated in the main arm cavity 2111; then, the post-filter 100 and the pre-filter 200 are withdrawn backward and forward, respectively.

Preferably, but not limited to, as shown in fig. 2 and 4, the spring 13 is sleeved outside the rear recovery rod 12 to improve the stability of the motion.

In an alternative implementation manner of the present embodiment, as shown in fig. 12, preferably, a socket 4101 extending along the extending direction of the front main anchor arm 41 is provided at the free end of the front main anchor arm 41, and an avoidance slot 4102 is provided on the side wall of the free end of the front main anchor arm 41; in the implanted state, as shown in fig. 15 and 16, the free end of the main arm 211 in the back filter 100 is inserted into the insertion cavity 4101 of the free end of the front main anchor arm 41 in the front filter 200, the anchor hook 2121 of the free end of the anchor arm 212 in the back filter 100 passes through the avoiding slot 4102, and the design of the avoiding slot 4102 can limit the penetration angle when the anchor hook 2121 penetrates into the vessel wall, and simultaneously, when the anchor hook 2121 withdraws from the vessel wall, the free end of the avoiding slot 4102 withdraws from the original angle under the limit of the avoiding slot 4102 so as to reduce the damage to the vessel wall, and the avoiding slot 4102 is preferably separated from the end face of the free end of the front main anchor arm 41 by a certain distance so as to improve the connection firmness between the front main anchor arm 41 and the back main anchor arm 21 in the state that the anchor hook 2121 penetrates into the vessel wall.

Further preferred but not limited to: as shown in fig. 12, the above-mentioned socket 4101 extends to the free end of the front main anchor arm 41, and the socket 4101 includes a diameter-changing portion 41011 gradually increasing in diameter from the free end of the front main anchor arm 41 toward the retracting hook 3. In this structure, the plugging cavity 4101 extends to the free end of the front main anchor arm 41, which is more convenient for plugging; the reducing portion 41011 avoids the setting of the socket 4101 to weaken the front main anchor arm 41, and improves the service life of the front filter 200.

Preferably, but not limited to, the above-mentioned socket 4101 penetrates the front main anchor arm 41 in the extending direction of the front main anchor arm 41.

With continued reference to fig. 1 to 5, in an alternative implementation of the present embodiment, it is preferable that the back filter arm 2 includes at least two back main anchor arms 21 and at least two back auxiliary arms 22, and the back main anchor arms 21 and the back auxiliary arms 22 are staggered with each other along the circumferential direction of the back recovery hook 1; in the implanted state, all rear main anchor arms 21 are opened to be umbrella-shaped; all the rear auxiliary arms 22 are opened in a half-shuttle shape, and the free ends of the respective rear auxiliary arms 22 are supported on the inner wall of the blood vessel; with continued reference to fig. 10 to 14, the front filter arm 4 preferably comprises at least two front main anchor arms 41 and at least two front auxiliary arms 42, the front main anchor arms 41 and the front auxiliary arms 42 being staggered with each other along the circumference of the front recovery hook 3; in the implanted state, all the front main anchor arms 41 are opened in an umbrella shape, all the front auxiliary arms 42 are opened in a half-shuttle shape, and the free ends of the respective front auxiliary arms 42 are supported on the inner wall of the blood vessel. Referring to fig. 18, in the implanted state, the free ends of the respective posterior auxiliary arms 22 of the posterior filter 100 and the free ends of the respective anterior auxiliary arms 42 of the anterior filter 200 are respectively supported on the inner wall of the blood vessel as auxiliary anchor points B2, thereby further improving the centering stability of the combined vena cava filter in the blood vessel after implantation.

In this embodiment, more preferably, as shown in fig. 15, the recovery hook of the front filter 200 includes a front housing 31 and a front recovery lever 32; the front recovery lever 32 passes through and is fixed to the front housing 31; one end of all filter arms of the front filter 200 is fixedly connected to the front housing 31, respectively; the implantation state is as follows: the free end of the anterior retraction rod 32 and the free end of the posterior retraction rod 12 are inter-connected to further enhance the neutral alignment and stability after implantation.

Further preferably, the front recovery hook 3 further comprises a front baffle 33; the front baffle 33 is disposed in the inner cavity of the front housing 31 and is sleeved and screwed on the outer peripheral wall of the front recovery rod 32 to fix the front recovery rod 32 to the front housing 31, as shown in fig. 13, a front radial bulge 3202 is disposed on the front recovery rod 32 at a position outside the front housing 31, the outer diameter of the front radial bulge 3202 is larger than the aperture of the recovery rod perforation on the front housing 31 to limit the front recovery rod 32 relative to the front housing 31, and a connecting portion for temporarily connecting with the recoverer is disposed on the position of the front recovery rod 32 outside the front housing 31, and the connecting portion may be, but not limited to, a front hook portion 3201 with a hook shape as shown in fig. 13, or a screw structure or a ring structure with an external thread. One end of the front main anchor arm 41 and one end of the front auxiliary arm 42 are fixedly connected to the front housing 31 at intervals in the circumferential direction of the front housing 31, and in the circumferential direction of the front housing 31: the front main anchor arm 41 is interleaved with the front auxiliary arm 42.

In addition, in the present embodiment, it is preferable but not limited to: with the side surface of the free end of the main arm 211 of the rear main anchor arm 21 contacting the free end of the front main anchor arm 41 in the implanted state being the first side surface, the side surface of the free end of the front main anchor arm 41 contacting the free end of the main arm 211 of the rear main anchor arm 21 is the second side surface: a plurality of first arc-shaped fastening protrusions 2110 are provided on the first side surface, and a plurality of second arc-shaped fastening protrusions 410 are provided on the second side surface; in the implanted state, the first arc-shaped buckling protrusion 2110 and the second arc-shaped buckling protrusion 410 are in staggered snap fit, so that the stable reliability of the plugging or clamping position is ensured.

Furthermore, in this embodiment, the angle between each adjacent two filter arms is preferably the same, either in the front filter 200 or in the rear filter 100, to further enhance the centering stability; for example, but not limited to, as shown in fig. 5 and 14, in the front filter 200 or in the rear filter 100, each filter arm has 12 filter arms, and the included angle between two adjacent filter arms is 30 degrees.

Example two

The present embodiment provides a recyclable vena cava filter, which can be applied as a post-filter 100 to the combination vena cava filter described in the foregoing embodiment one, referring to fig. 1 to 5.

Specifically, the recyclable vena cava filter includes a rear recycling hook 1 and a plurality of rear filter arms 2 connected to the rear recycling hook 1 at circumferential intervals and extending toward the same side as the rear recycling hook 1. As shown in fig. 1 to 9, in the recyclable vena cava filter, the rear recycling hook 1 includes a rear housing 11, a rear recycling rod 12 and a spring 13, the rear recycling rod 12 passes through the rear housing 11 and is connected to the rear housing 11 through the spring 13, a connection part is provided at a portion of the rear recycling rod 12 located outside the rear housing 11, and the connection part is used for temporary connection with a recycling device, and may be a bent hook-shaped rear hooking part 1201, or be provided with an external thread or a ring structure, etc.

The rear filter arm 2 comprises at least two rear main anchor arms 21, each rear main anchor arm 21 comprising a respective main arm 211 and anchor arm 212; a main arm chamber 2111 penetrating the main arm 211 in the extending direction of the main arm 211 is provided in the main arm 211, and a main arm slit 2112 communicating with the main arm chamber 2111 is provided in the peripheral wall of the free end of the main arm 211; the anchor arm 212 passes through the main arm cavity 2111 and the free end of the anchor arm 212 is provided with an anchor hook 2121 which is resiliently bent radially outwardly, the whole of the anchor arm 212 preferably but not limited to being prefabricated from a pinch titanium alloy or other memory metal which gives it a free state in a bent shape with the anchor hook 2121. One end of the main arm 211 is fixedly connected to the rear housing 11 and communicates with the inner cavity of the rear housing 11, and one end of the anchor arm 212 is connected to the rear recovery lever 12. The spring 13 is configured to be capable of pushing the anchor arm 212 in a free state with respect to the main arm 211 in a free end direction of the main arm 211 so that the anchor hook 2121 protrudes out of the main arm notch 2112, and to be elastically deformed when the recovery lever 12 is pulled in an external direction of the rear housing 11 by an external force through the recovery device so as to pull the anchor arm 212 back in a direction of the rear housing 11 with respect to the main arm 211, thereby elastically deforming and accommodating the anchor hook 2121 in the main arm cavity 2111.

In the implanted state, all the rear main anchor arms 21 are opened, the anchor arms 212 slide towards the free end direction of the main arms 211 relative to the main arms 211 under the elastic force of the springs 13, so that the anchor hooks 2121 at the free ends of the anchor arms 212 extend out of the main arm slots 2112 at the free ends of the main arms 211 to be anchored on the inner wall of the blood vessel, as shown in fig. 3, the angle between the extended anchor hooks 2121 and the anchor arms 212 is theta, preferably, but not limited to, more than 10 degrees and less than 35 degrees, and the length of the extended anchor hooks 2121 extending out of the main arm slots 2112 is preferably, but not limited to, 1mm-1.5mm; in the recovery state, the connecting part of the rear recovery rod 12 positioned outside the rear housing 11 is connected to the rear housing 11 through the recoverer, the rear recovery rod 12 is retracted outside the rear housing 11 relative to the rear housing 11, the rear recovery rod 12 slides backwards along the inner wall of the rear housing 11 against the elastic force of the spring 13, and the anchoring arm 212 slides backwards relative to the main arm 211 until the anchoring hook 2121 is elastically deformed and accommodated in the main arm cavity 2111.

The recyclable vena cava filter can be used alone in addition to the combination with the pre-filter 200 according to the first embodiment, in the following manner:

referring to fig. 6 and 7, taking an example of applying the recyclable vena cava filter to the inferior vena cava 300, a vena cava filter delivery system with the recyclable vena cava filter is implanted into the inferior vena cava 300 through the femoral vein or the jugular vein by a puncturing method, and the vena cava filter delivery system is operated to release the recyclable vena cava filter to retrieve the vena cava filter delivery system. The state after the release of the reusable vena cava filter, the front end of which is located upstream in the blood flow direction and the rear end of which is located downstream in the blood flow direction, is shown in fig. 6 and 7, and the rear main anchor arm 21 of the rear filter arm 2: the anchor arms 212 are pushed forward relative to the main arms 211 by the elastic force of the springs 13, the anchor hooks 2121 at the free ends of the anchor arms 212 extend out of the main arm slots 2112 at the free ends of the main arms 211 and are anchored on the inner wall of the blood vessel to serve as main anchor points B1, and as one end (rear end) of each of the rear filter arms 2 is fixedly connected with the rear recovery hooks 1, the free ends (front ends) of each of the rear filter arms 2 extend towards the front sides of the rear recovery hooks 1, all of the rear main anchor arms 21 in the rear filter arms 2 are opened in the implanted state, so that blood flows through the rear main anchor arms 21 to be hung on the opened rear main anchor arms 21 and is intercepted in the inner central area after all of the rear main anchor arms 21 are opened, the function of a filtering plug is achieved, and during the period, the recoverable vena cava filter has the advantages of multiple attachment points, firm wall grasping and good adherence.

When it is desired to retrieve (reclaim) the recyclable vena cava filter, referring to fig. 8 and 9, a vena cava retriever is implanted from the femoral vein or jugular vein into the inferior vena cava 300 by puncturing, the retriever is temporarily connected to the connecting portion of the rear retrieving hook 1 of the recyclable vena cava filter, the retriever is operated to retract the rear retrieving lever 12 relative to the rear housing 11, and further the rear retrieving lever 12 slides rearward along the inner wall of the rear housing 11 against the elastic force of the spring 13, with the anchor arm 212 sliding rearward relative to the main arm 211 until the anchor hook 2121 elastically deforms to be accommodated in the main arm cavity 2111, and thereafter, the filter retriever is operated to take out the recyclable vena cava filter. The extraction process is simple and efficient, in addition, the angle theta between the anchoring hook 2121 and the anchoring arm 212 after extending out of the main arm notch 2112 is more than or equal to 10 degrees and less than or equal to 35 degrees, and under the smaller angle theta, the anchoring hook 2121 is easier to obliquely penetrate into the blood vessel wall and is also easier to retract from the blood vessel wall, repeated scraping and rubbing of the blood vessel wall can be avoided in the penetrating process, the retracting process is fast retracted according to the original penetrating angle, the anchoring hook 2121 is not only used for penetrating into or retracting from the blood vessel wall, but also the damage to the blood vessel wall is very small, and the problem that the blood vessel wall cannot be extracted due to pulling damage when the anchoring hook 2121 is directly pulled outwards along the blood vessel flow direction is avoided.

When the recyclable vena cava filter provided in this embodiment is used alone, the technical problem that the vena cava filter cannot be retrieved after endothelialization of the umbrella-shaped vena cava filter and the vascular wall in the prior art described in the background art can be relieved.

The reusable vena cava filter may be provided with other optional structures such as the additional rear auxiliary arm 22, etc. in addition to the above structures, and specific optional structures may be obtained meaninglessly with reference to the structure of the rear filter 100 in the first embodiment.

Finally, it should be noted that: in the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described by differences from other embodiments, and identical and similar parts between the embodiments are only required to be seen with each other; the above embodiments in the present specification are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims

1. A combination vena cava filter, characterized in that: comprises a back filter (100) and a front filter (200);

-the back filter (100) and the front filter (200) comprise a respective recovery hook and a plurality of filter arms connected to the recovery hook at circumferentially spaced intervals and extending towards the same side of the recovery hook;

the filter arm of the back filter (100) comprises at least two back main anchor arms (21) and at least two back auxiliary arms (22), and the back main anchor arms (21) and the back auxiliary arms (22) are distributed in a staggered manner along the circumferential direction of the recovery hook of the back filter (100); each rear main anchor arm (21) comprises a main arm (211) and an anchor arm (212); a main arm cavity (2111) penetrating through the main arm (211) along the extending direction of the main arm (211) is formed in the main arm (211), and a main arm cutting groove (2112) communicated with the main arm cavity (2111) is formed in the peripheral wall of the free end of the main arm (211); the anchoring arm (212) passes through the main arm cavity (2111), and the free end of the anchoring arm (212) is provided with an anchoring hook (2121) which is elastically bent outwards in a radial direction; the recovery hook of the back filter (100) comprises a back shell (11), a back recovery rod (12) and a spring (13), wherein the back recovery rod (12) penetrates through the back shell (11) and is connected with the back shell (11) through the spring (13), a connecting part is arranged at the position, outside the back shell (11), of the back recovery rod (12), and the connecting part is used for being temporarily connected with a recoverer; one end of the main arm (211) is fixedly connected to the rear shell (11) and is communicated with the inner cavity of the rear shell (11), and one end of the anchoring arm (212) is connected to the rear recovery rod (12);

the filter arm of the front filter (200) comprises at least two front main anchor arms (41) and at least two front auxiliary arms (42), and the front main anchor arms (41) and the front auxiliary arms (42) are distributed in a staggered manner along the circumferential direction of the recovery hook of the front filter (200); a free end of the front main anchor arm (41) is provided with a splicing cavity (4101) extending along the extending direction of the front main anchor arm (41), and a free end side wall of the front main anchor arm (41) is provided with an avoidance groove (4102);

in an implanted state, the back filter (100) is arranged opposite to the front filter (200), and all the back auxiliary arms (22) are opened to be supported on the inner wall of the blood vessel in a half-shuttle shape, and all the front auxiliary arms (42) are opened to be supported on the inner wall of the blood vessel in a half-shuttle shape; the free ends of main arms (211) in the back filter (100) are correspondingly inserted into the insertion cavities (4101) of the free ends of front main anchor arms (41) in the front filter (200), the springs (13) are used for pushing the anchoring arms (212) towards the free ends of the main arms (211) relative to the main arms (211), so that the anchoring hooks (2121) extend out of the main arm slots (2112) and penetrate through the avoiding slots (4102) to be anchored on the inner wall of a blood vessel, and the angle theta between the anchoring hooks (2121) and the anchoring arms (212) after extending out of the main arm slots (2112) is less than or equal to 10 degrees and less than or equal to 35 degrees;

in the recovery state, the front filter (200) is withdrawn forwards, the rear recovery rod (12) is pulled towards the external direction of the rear shell (11) through the recoverer, so that the spring is elastically deformed to pull the anchoring arm (212) back towards the rear shell (11) relative to the main arm (211), the anchoring hook (2121) is elastically deformed to be accommodated in the main arm cavity (2111), and then the rear filter (100) is withdrawn backwards.

2. The combination vena cava filter as in claim 1, wherein: the recovery hook of the back filter (100) also comprises a back baffle (14); the rear baffle (14) and the spring (13) are both arranged in the inner cavity of the rear shell (11), and the rear baffle (14) is circumferentially limited inside the rear shell (11) so that the rear baffle (14) can slide back and forth inside the rear shell (11) but cannot rotate circumferentially; the rear baffle (14) is sleeved and connected with the outer peripheral wall of the rear recovery rod (12) in a threaded mode, and the spring (13) is arranged between the rear baffle (14) and the inner wall surface of the rear shell (11).

3. The combination vena cava filter as in claim 1, wherein: the socket (4101) extends to a free end of the front main anchor arm (41), and the socket (4101) includes a diameter-changing portion (41011) having a diameter gradually increasing from the free end of the front main anchor arm (41) toward the recovery hook direction of the front filter (200).

4. A combination vena cava filter as in claim 1 or 3, wherein: the socket (4101) penetrates the front main anchor arm (41) in the extending direction of the front main anchor arm (41).

5. The combination vena cava filter as in claim 1, wherein:

the recovery hook of the front filter (200) comprises a front shell (31) and a front recovery rod (32); the front recovery rod (32) passes through and is fixed to the front housing (31); one end of all filter arms of the front filter (200) is fixedly connected to the front shell (31) respectively;

the implantation state is as follows: the free end of the front recovery rod (32) and the free end of the rear recovery rod (12) are mutually spliced.

6. The combination vena cava filter as in claim 1, wherein:

in the implanted state, the side surface of the free end of the main arm (211) in the rear main anchor arm (21) contacting the free end of the front main anchor arm (41) is a first side surface, and the side surface of the free end of the front main anchor arm (41) contacting the free end of the main arm (211) in the rear main anchor arm (21) is a second side surface, then:

a plurality of first arc-shaped buckling protrusions (2110) are arranged on the first side surface, a plurality of second arc-shaped buckling protrusions (410) are arranged on the second side surface, and in an implanted state, the first arc-shaped buckling protrusions (2110) and the second arc-shaped buckling protrusions (410) are in staggered snap fit.