CN212308116U - Vein filter - Google Patents

Abstract

The utility model relates to a vein filter, include: the filter comprises a recovery piece, a connecting piece and a plurality of filter wires, wherein the end parts of the plurality of filter wires are fixed in the connecting piece, and the other side of the connecting piece is connected with the recovery piece; the connecting piece includes: a filter wire fixing member; the end part of the filter wire is fixedly connected with the filter wire fixing part, and the filter wire fixing part is detachably connected with the recovery part. The vein filter can intercept thrombus through the filter wire, thereby realizing the function of intercepting thrombus and preventing pulmonary embolism; can inhibit the adhesion and growth of local endothelial cells contacted with the filter wire, and reduce the incidence of a series of complications such as difficult extraction, blood vessel injury or laceration and the like caused by delayed extraction; by removing the recovery piece, after the high-molecular absorbable line at the head end of the filter wire is degraded, the umbrella-shaped filter screen is automatically unfolded to become a vena cava bracket, so that the influence of the filter wire on the hemodynamics of the vein is reduced to the maximum extent, and the risk of DVT (vascular endothelial necrosis factor) caused by the permanent intracavity implant is reduced.

Description

Vein filter

Technical Field

The utility model relates to a design technical field of implantable intravascular filter in medical equipment especially relates to a vein filter.

Background

Deep Venous Thrombosis (DVT) refers to the process of coagulation of blood or the coagulation of certain constituents in the blood to form a solid mass within a Deep Venous blood vessel, usually found in peripheral veins. Pulmonary Thromboembolism (PE) refers to a syndrome of dysfunction of the heart and lungs caused by emboli shed from peripheral veins entering the Pulmonary circulation along with the blood flow and blocking the blood supply in the lungs. DVT and PE are collectively called Venous Thromboembolism (VTE), the incidence of VTE in the United states is about 300000-600000 cases/year, PE can cause 10-20 million deaths in the United states each year, and it is a major public health problem. Clinically, the incidence of sudden death of PE is about 5%, the disease is second to coronary heart disease and hypertension, and the mortality rate is third after tumor and myocardial infarction. DVT is a high risk factor for PE, with up to over 90% of emboli in PE originating from shedding of DVT in the lower extremities, particularly in the proximal segment of the above knee. When the area of embolism exceeds 50% -80% of the pulmonary artery, sudden death of a patient is very likely to be caused, and researches show that fine thromboembolism is difficult to cause PE, and the PE can be caused only when the diameter of the thromboembolism is larger than a certain range. Previous clinical studies have shown that more than 33% of patients can develop symptomatic PE after a lower limb DVT occurs, with 10% of symptomatic PE being fatal; however, in the actual course of disease, since PE is mostly asymptomatic, the rate of misdiagnosis and missed diagnosis of the disease is high, and prevention of PE is more important than treatment of PE itself in clinical treatment.

The Inferior Vena Cava Filter (IVCF) is an implantable medical device similar to a Filter screen, and is generally placed in the Inferior Vena Cava to effectively prevent the development of DVT into PE by physically obstructing floating thrombus. Since the appearance of Mobin-Uddin umbrella IVCF in 1967, the clinical application is becoming more and more extensive, and the Mobin-Uddin umbrella IVCF is one of the main measures for preventing the occurrence of PE. Three types of IVCF appeared in succession according to clinical use, and classified into permanent, temporary and recoverable IVCF according to the time of implantation.

IVCF was originally designed for permanent implantation, but in a prospective randomized controlled trial patients with permanent IVCF implantation were followed up to 8 years. The research result shows that: recoverable IVCF helps to reduce the risk of pulmonary embolism and distant DVT recurrence, thus facilitating the development of recoverable IVCF. A number of clinical practices have shown that the longer the retrievable IVCF is placed, the lower the success rate of retrieval. Thus, the FDA in the united states emphasized the risk of long-term retention of recoverable filters in 2010 and suggested that clinicians should be responsible for filter recovery with filter placement physicians when prevention of pulmonary embolism is no longer needed.

IVCF is typically placed by conventional femoral or jugular vein access with mild complications including local hematoma/thrombosis and hemorrhage after placement. Wherein, the complication and incidence after IVCF operation are thrombosis (2-30%), PE recurrence (0.5-6%), filter fracture (2-10%), filter embolism, filter displacement (2-10%) and IVC penetration/perforation (0-50%); while the major complications of recoverable IVCF at recovery include inferior vena cava thrombosis (4.3%) and inferior vena cava injury/tear (0.88%). Delayed IVCF removal time increases the likelihood of filter and vessel wall sticking to each other, which correspondingly reduces recovery success and increases the risk of complications. Research shows that IVCF and blood vessel wall adhesion mostly occurs 9-12 weeks after implantation, the time window for taking out most of the recoverable IVCF is usually within 14 days at present, in the actual clinical diagnosis and treatment process, many patients cannot take out the recoverable IVCF due to vascular endothelial hyperplasia and filter adhesion, the recoverable IVCF is forced to become permanent IVCF and is kept in the body as a permanent implant for a long time, and the filter can have complications such as inclination, displacement, embolism, rupture, blood vessel puncture and the like, so the filter is often used as a potential hazard and needs to be observed by regular follow-up visits.

The mechanism of action of drugs in inhibiting the proliferation and growth of endothelial cells mainly includes the aspects of interfering nucleic acid biosynthesis, destroying and interfering DNA structure and function, interfering cell protein synthesis and the like. The endostatin is a protein which is separated and extracted from a culture solution of a mouse endothelial tumor cell line EOMA in 1997 and can specifically inhibit the proliferation and migration of vascular endothelial cells, has obvious effects of inhibiting the proliferation and migration of the vascular endothelial cells, can cause the cell growth cycle arrest and apoptosis of the vascular endothelial cells, and has specificity to the vascular endothelial cells. With the continuous and intensive research on endostatin, researchers have confirmed that nucleolin on the surface of cell membranes is a receptor for endostatin, which inhibits the phosphorylation of nucleolin to achieve the function of inhibiting the growth of new blood vessels and tumor growth. In addition, the vascular endothelial growth factor also serves as an important target for inhibiting the proliferation and growth of endothelial cells, and more anti-vascular endothelial growth factor medicines are proved to have the effect of resisting vascular endothelial proliferation and have the treatment effect in clinical practice from the initial pegaptanib sodium to the monoclonal antibodies bevacizumab and ranibizumab and then to the later antibody fusion proteins aflibercept and comboxipt for the research and development of the anti-vascular endothelial growth factor medicines.

Currently, there is a need for a switchable inferior vena cava filter that inhibits endothelial cell adhesion growth, slows vascular endothelial proliferation at the site of contact, prolongs the time window for removal, and is stable in vivo and reduces associated complications after switching to a permanent implant in the course of a clinical PE prevention therapy.

SUMMERY OF THE UTILITY MODEL

In view of the above, the main object of the present invention is to provide a venous filter which can inhibit the adhesion and growth of endothelial cells, slow down the endothelial proliferation of blood vessels at the contact site, prolong the time window for removal, and after conversion into a permanent implant, can be stably present in the body and reduce the related complications.

In order to achieve the above purpose, the technical scheme of the utility model is realized like this:

a venous filter, comprising: the filter device comprises a recovery piece, a connecting piece and a plurality of filter wires, wherein the end parts of the filter wires are fixed in the connecting piece, and the other side of the connecting piece is connected with the recovery piece; the connector includes: a filter wire fixing member; the end part of the filter wire is fixedly connected with the filter wire fixing part, and the filter wire fixing part is detachably connected with the recovery part.

In a preferred embodiment, the connector further comprises: a connecting hook; the filter wire fixing piece and the recovery piece are detachably connected through a connecting hook; one end of the connecting hook is connected with the recovery part, and the other end of the connecting hook is detachably connected with the filter wire fixing part.

In a preferred embodiment, the coupling hook includes: an upper bending part, a connecting part and a lower bending part; the upper bending part, the connecting part and the lower bending part are sequentially and integrally formed.

In a preferred embodiment, the upper bending part at the upper end of the connecting hook is connected with the recovery part, and the connecting part is connected with the filter wire fixing part in a sliding manner; the lower bending part is provided with a cutting edge towards one side of the connecting part, so that the recovery part pulls the connecting hook to cut the filter wire fixing part, and the connecting hook is separated from the filter wire fixing part.

In a preferred embodiment, the filter wire fixing member is a polymer absorbable wire, the polymer absorbable wire is wound and bound on an end of the filter wire, and the other end of the polymer absorbable wire is wound and sleeved on the connecting portion of the connecting hook.

In a preferred embodiment, the recovery member comprises: the recycling device comprises a recycling shell and a recycling head, wherein one end of the recycling shell is of a sealing structure; the one end of retrieving the head is equipped with retrieves connection structure, the other end of retrieving the head and retrieving the sealing end outside fixed connection of shell.

In a preferred embodiment, the filter wire fixing member is disposed inside the recycling shell, and the upper bending portion of the connecting hook extends out of the sealing end of the recycling shell.

In a preferred embodiment, the connecting hook is of a Z-shaped structure, the lower bending portion bends towards the center of the recycling shell, the end, far away from the connecting portion, of the upper bending portion is integrally formed with an auxiliary hook towards the side close to the recycling shell, and the auxiliary hook is connected with the outer wall of the recycling shell in a relatively limited manner.

In a preferred embodiment, the number of the connecting hooks is 1-4.

In a preferred embodiment, the number of the connecting hooks is 2, and the connecting hooks are symmetrically arranged relative to the recycling shell.

In a preferred embodiment, the filter filaments comprise 6 to 10.

In a preferred embodiment, each of the filter wires comprises at least two strands, one end of each of the filter wires is wound and fixed, a middle portion of each of the filter wires is separated to form a net shape, and the other end of each of the filter wires is fixed by a filter wire fixing member.

In a preferred embodiment, each filter wire comprises two strands, and one end parts of the two strands are mutually wound and fixedly connected;

two filter wires are separated at the middle position, and each filter wire crosses one filter wire of the other adjacent filter wire to enable the two filter wires to be sleeved together in a crossing manner;

the other ends of the two filter wires are fixed by the filter wire fixing piece.

In a preferred embodiment, a plurality of the filter wires enclose a filter screen, and the filter screen is partially opened to have a maximum diameter of 15-30mm in a natural state.

In a preferred embodiment, each of said filter filaments has a diameter of 0.1-0.2 mm.

In a preferred embodiment, the material of the recovery member, the connecting member and the filter wire is nickel titanium alloy.

In a preferred embodiment, the outer surface of the filter wire is modified and coated with drug-loaded nanoparticles that inhibit the adhesion and growth of endothelial cells.

In a preferred embodiment, the drug-loaded nanoparticles have a diameter of 10 to 1000 nm.

In a preferred embodiment, the drug-loaded nanoparticle comprises: the filter wire comprises drug particles, an inner shell and an outer shell, wherein the inner shell wraps the outer portions of the drug particles, the outer shell wraps the outer portions of the inner shell, and the outer shell is connected to the surface of the filter wire in a coating mode.

In a preferred embodiment, the outer shell is composed of any one or two or more of polylactic acid-glycolic acid copolymer, polycaprolactone, and polylactic acid-glycolic acid.

In a preferred embodiment, the inner shell is composed of any one or two or three of butyl stearate, polylactic acid-glycolic acid copolymer, polyallylamine and polyethyleneimine.

In a preferred embodiment, the drug particles are any one or two or three or four of fibroblast growth factor receptor inhibitor, recombinant human vascular endostatin, paclitaxel and 5-fluorouracil.

In a preferred embodiment, the drug-loaded nanoparticle is prepared by adopting an O/W homogeneous emulsification method:

the method comprises the following steps:

preparing a solution of the medicinal granule components with the concentration of 1-8 percent g/ml;

dissolving the polylactic acid-glycolic acid copolymer in dichloromethane to form a polylactic acid-glycolic acid copolymer oil phase;

dispersing the medicine granule component solution and butyl stearate in the polylactic acid-glycolic acid copolymer oil phase to prepare a medicine-containing oil phase;

adding 0.1-1% polyvinyl alcohol solution into the oil phase containing medicine;

centrifuging and homogenizing at 1000-;

adding a rotor, and magnetically stirring for 4 hours;

centrifuging and collecting the microsphere solution;

washing with deionized water for three times to remove residual polyvinyl alcohol solution and the medicine adsorbed on the surfaces of the microspheres;

transferring the concentrated microsphere solution into a penicillin bottle;

freeze-drying with a freeze dryer to obtain medicinal granules containing inner shells;

dripping the medicinal granules containing the inner shell into a colostrum solution formed by dichloromethane solution containing 5-20% of the raw material of the outer shell under the ultrasonic condition; dropwise adding 0.05-2% carboxymethyl chitosan solution serving as an external water phase into the primary emulsion solution under the ultrasonic condition to obtain a multiple emulsion solution;

volatilizing the organic solvent in the multiple emulsion solution for 1-8 hours under the condition of electromagnetic stirring, and then centrifuging, washing and freeze-drying to obtain the solidified drug-loaded nanoparticles.

In a preferred embodiment, the method for coating the drug-loaded nanoparticles on the surface of the filter wire to obtain the nickel-titanium metal filter wire comprises the following steps:

carrying out surface mechanical polishing treatment on the nickel-titanium metal filter wire;

cleaning with ultrasonic in methanol solution for 1-20 min;

washing with deionized water, and drying with compressed air;

placing the dried nickel-titanium metal filter wire in stable-state electron cyclotron resonance plasma generation equipment, regulating the vacuum degree to 1-10 x 10 < -3 > Pa, and keeping for 10-30 min;

introducing diethylene glycol dimethyl ether, keeping the air pressure at 10-50 Pa, keeping the frequency of microwave plasma at 1-5 GHz, and stopping reaction for 1-20 min; obtaining the nickel-titanium metal filter wire with a large number of chemical bonds of C ═ O, O-C ═ O and O-CO-O on the surface;

coating the drug-loaded nanoparticles on the surface of the nickel-titanium metal filter wire in a chemical bond combination mode through copolymerization reaction; obtaining the nickel titanium metal filter wire coated with drug-loaded nano-particles for inhibiting the adhesion and growth of endothelial cells.

The utility model discloses a vein filter has following beneficial effect:

the venous filter comprises: the filter comprises a recovery piece, a connecting piece and a plurality of filter wires, wherein the end parts of the plurality of filter wires are fixed in the connecting piece, and the other side of the connecting piece is connected with the recovery piece; the connecting piece includes: a filter wire fixing member; the end part of the filter wire is fixedly connected with the filter wire fixing part, and the filter wire fixing part is detachably connected with the recovery part.

The vein filter can intercept thrombus through filter wires, so that the vein filter (which can be an inferior vena cava filter) realizes the function of intercepting thrombus and preventing pulmonary embolism; the surface modification treatment of the drug-loaded nanoparticles is carried out on the outer surface of the nickel-titanium alloy filter wire, so that the adhesion and growth of local endothelial cells contacted with the filter wire can be inhibited, and the incidence rate of a series of complications such as difficult taking out, blood vessel injury or tearing and the like caused by delayed taking out is reduced; by removing the recovery piece, when the polymer absorbable line at the head end of the filter wire is degraded, the umbrella-shaped filter screen is automatically unfolded to become a vena cava bracket, so that the influence of the filter wire on the hemodynamics of the vein is reduced to the maximum extent, and the risk of DVT (vascular endothelial necrosis factor) caused by the permanent intracavity implant is reduced; the utility model discloses the utility model is strong, convenient operation.

Drawings

FIG. 1 is a schematic diagram of a venous filter according to one embodiment of the present disclosure;

FIG. 2 is a top view of the venous filter of FIG. 1 according to one embodiment of the present disclosure;

FIG. 3 is a partial cross-sectional view of the venous filter of FIG. 1 shown at the connection thereof according to one embodiment of the present disclosure;

fig. 4 is a structural diagram illustrating a coated state of drug-loaded nanoparticles and filter filaments of a vein filter according to an embodiment of the present disclosure.

[ description of main reference symbols ]

1. A recovery piece 11, a recovery shell 12 and a recovery head;

2. a connecting piece 21, a filter wire fixing piece;

22. a connecting hook 221, an upper bending part 222, a connecting part 223, a lower bending part 224 and an auxiliary hook;

3. filtering the silk;

4. drug-loaded nanoparticles, 41, drug particles, 42, inner shells, 43, outer shells.

Detailed Description

The vein filter of the present invention will be described in further detail with reference to the accompanying drawings and embodiments of the present invention.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

For ease of description, spatially relative terms such as "above … …"),

"above … …", "on … …", "above", and the like, are used to describe one device or feature as it appears in the figures in relation to another device or feature in spatial position. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

As shown in fig. 1 to 4, the venous filter includes: a retrieval member 1 which can be detachably connected with an interventional device; the end part of the filter wire 3 is fixed, and the filter wire 3 can be separated from the recovery part 1 (when the recovery part 1 is recovered, the filter wire 3 can be selectively left in a human body, so that the filter wire is prevented from being adhered to a blood vessel, and the filter wire 3 is not easy to separate); a filter wire 3 for filtering thrombus in blood vessel. The end parts of the filter wires 3 are fixed inside the connecting piece 2, and the other ends of the filter wires 3 are supported and hooked with the inner wall of the blood vessel to be filtered, so that the filter wires 3 are opened by taking the connecting piece as the center to form a filter screen. The recovery member 1 is attached to the other side of the attachment member 2 for ease of access.

Preferably, the vein filter is an inferior vena cava filter, which can be placed at a position of the inferior vena cava between the inferior of the renal vein and the level above the iliac bifurcation in a human body.

In order to fix the filter wire 3 conveniently, the filter wire 3 and the recovery member 1 can be separated from each other. This connecting piece 2 includes: a filter wire fixing member 21; the end of the filter wire 3 is fixedly connected with the filter wire fixing member 21, and the filter wire fixing member 21 is detachably connected with the recovery member 1.

Preferably, the recovery member 1 is a recovery hook, that is: the recovery piece 1 is of a rod-shaped structure, a notch is formed in one side wall of the recovery piece 1, and one end, far away from the filter wire 3, of the notch is of a hook-shaped structure. Namely: forming a filtering wire mesh with an umbrella-shaped structure.

The filter wires 3 are conveniently separated from the recovery member 1, especially in the process of vascular interventional operation. The connector 2 further comprises: a connecting hook 22; the filter wire fixing piece 21 and the recovery piece 1 are detachably connected through a connecting hook 22. One end of the connecting hook 22 is connected with the recovery part 1, and the other end of the connecting hook 22 is detachably connected with the filter wire fixing part 21.

Further, in the blood vessel, the separation of the filter wire fixing member 21 cannot be conveniently operated in the interventional operation process, and in order to realize the separation of the filter wire fixing member 21 and the connecting hook in the interventional operation process. The coupling hook 22 includes: an upper bent portion 221, a connection portion 222, and a lower bent portion 223; the upper bending part 221, the connecting part 222 and the lower bending part 223 are integrally formed in sequence;

the upper bending part 221 at the upper end of the connecting hook 22 is connected with the recovery part 1 (which can be clamped, or can be lapped on the surface of the recovery part 1 through bending of the upper bending part 221 to limit the position of the whole connecting hook 22), and the connecting part 222 is in sliding connection with the filter wire fixing part 21 (the connecting part is prevented from being too strong and difficult to separate, so that the connecting part can be conveniently cut off through the lower bending part 223 by selecting sliding connection, thereby realizing separation between the connecting hook 22 and the filter wire fixing part 21); one side of the lower bending portion 223 facing the connecting portion 222 is provided with a cutting edge, so that the recovery member 1 pulls the connecting hook 22 to cut the filter wire fixing member 21 to separate the connecting hook 22 from the filter wire fixing member 21.

The filter wire fixing member 21 may have various structures, but the material thereof is selected to be interpretable in blood, so that interpretation within a set time after separation is ensured, and the restraint of the filter wire 3 is released. The structure of the filter wire 3 is stretched to be cylindrical; the filter wire net of original umbrella-shaped structure loosens at the tip of filter wire mounting 21 promptly, and filter wire 3 struts to tubular structure, further can support the vein, forms venous stent, has not only avoided the hindrance to blood (defect such as thrombus formation), can guarantee again to reduce filter wire to venous hemodynamics's influence to the at utmost to reduce the risk that permanent intracavity implant arouses DVT.

Preferably, the filter fixing member 21 is a polymer absorbable thread. The components of the polymer absorbable line are as follows: the medical suture is made of high molecular materials such as polyglycolic acid, polylactic acid, poly-p-dioxanone and the like. (the vein filter does not degrade during working (the unexplained time length is controlled through the adjustment of the components), the polymer line needs to keep certain mechanical strength to play a role in firm connection, and the effect of periodically starting degradation can be realized by adjusting the proportion of the components which can be absorbed by the polymer, namely, the polymer line starts to degrade after a patient spends a dangerous period, for example, the polymer line can be set to start to degrade 1 year after being implanted). The polymer absorbable wire is wound and bound on the end part of the filter wire 3 (ensuring the binding connection fixing strength and further ensuring that the filter wire 3 can stably work in the umbrella-shaped net working process and ensuring the filtering effect on thrombus); the other end of the polymer absorbable wire is wound and sleeved with the connecting part 222 of the connecting hook 22 (sleeved connection, so that the filter wire 3 and the connecting part 222 can slide relatively, friction between the filter wire and the connecting part 222 is reduced, cutting can be smoothly performed through the cutting edge of the lower bending part 223, and separation between the filter wire 3 and the filter wire fixing part 21 is further achieved).

In order to wrap the filter wire fixing part 21 and the connecting hook, the smooth intervention process is ensured. This recovery member 1 includes: the recovery shell 11 is used for wrapping the end part of the filter wire 3, the filter wire fixing piece 21 and the connecting hook 22; and the recovery head 12 is connected with the intervention equipment, so that the intervention, the placement and the recovery operation are convenient. For the convenience of connection with the recycling head 12, one end of the recycling shell 11 is of a sealing structure. One end of the recovery head 12 is provided with a recovery connection structure (i.e. a notch structure), and the other end of the recovery head 12 is fixedly connected with the outer side of the sealing end of the recovery shell 11.

The filter wire fixing piece 21 is arranged inside the recovery shell 11, and the upper bending part 221 of the connecting hook 22 extends out of the sealing end of the recovery shell 11; the connection between the upper bending part 221 and the recycling shell 11 is ensured, and a certain relative rotation is possible, but the connection cannot be separated.

Preferably, the connecting hook 22 is of a Z-shaped structure, so that the structure is more reasonable, the occupied space of the recycling shell 11 is reduced, and further the structure is more reasonable. Namely: lower kink 223 is to retrieving shell 11 center department bending, goes up the one end that kink 221 kept away from connecting portion 222 and has supplementary 224 of colluding to one side integrated into one piece near retrieving shell 11, supplementary colluding 224 and retrieving the relative spacing of shell 11 outer wall and being connected (through retrieving shell 11 outer wall, the supplementary position of colluding 224 of restriction, guarantee to connect colluding 22 and retrieve shell 11 and do not break away from), supplementary limiting displacement avoids going up kink 221 and retrieving and drop between the shell 11.

In order to ensure the connection strength with the recovery shell 11, the filter wire 3 can be conveniently controlled in the intervention placement process, and the success rate of the operation is ensured. The number of the connecting hooks 22 is 1-4.

Consider two factors of intervention equipment size and stability, it is preferred, the hookup 22 sets up 2, retrieves shell 11 hookup 22 symmetry setting relatively, guarantees to filter 3 steady fixed, has to guarantee the intervention equipment size, reduces the damage to patient's blood vessel.

In order to ensure the proper density of the filtering wire mesh with the umbrella-shaped structure, the thrombus can be filtered, and the normal blood circulation can be ensured. The filter wires 3 comprise 6 to 10.

In order to ensure the reasonability of the structure, the integral strength of the filtering screen structure can be improved. Every filter wire 3 includes two strands at least, and every filter wire 3's an end winding is fixed (guarantees fixed strength, and the connection is decided in the winding reinforcement), and every filter wire 3 middle part position part is latticedly, and a plurality of grids form network structure, and every filter wire 3's the other end is fixed through filter wire mounting 21. Further, the filtering wire net is formed in an umbrella-like (umbrella-like) structure, and the umbrella-like groove is a flow-facing surface (with respect to the blood flow direction).

Each of the filter wires 3 preferably includes two strands, and one end portion of each of the two strands is wound around and fixedly connected to each other. Two filter wires are separated at the middle position, and each filter wire crosses one filter wire of the other adjacent filter wire to enable the two filter wires to be sleeved together in a crossing manner; namely: the meshes formed by each filter wire are sleeved together, so that the strength of the whole filter screen is ensured. The other ends of the two filter wires are fixed by a filter wire fixing member 21.

Preferably, in order to fit the size of the inferior vena cava vessel of the human body. The filter screen is enclosed by a plurality of filter wires 3, and the maximum diameter of the filter screen is 15-30mm in the filter wires in a natural state.

Preferably, the filter wire is partially opened to a maximum diameter of 25 mm. Preferably, each filter wire 3 has a diameter of 0.1 to 0.2 mm.

In order to meet the requirements of placing and recovering the venous filter in the interventional operation, the recovering member 1, the connecting member 2 and the filter wire 3 are all made of nickel-titanium alloy materials.

To achieve a venous filter: can inhibit the adhesion and growth of local endothelial cells contacted with the filter wire, and reduce the incidence of a series of complications such as difficult taking out (adhesion of the filter screen and the inner wall of the blood vessel), blood vessel injury or tearing and the like caused by the delay of taking out; the outer surface of the filter wire 3 is modified and coated with drug-loaded nano particles 4 for inhibiting the adhesion and growth of endothelial cells.

Preferably, the outer surfaces of the recovery member 1 and the connecting member 2 are modified and coated with drug-loaded nanoparticles 4 for inhibiting the adhesion and growth of endothelial cells.

Preferably, the drug-loaded nanoparticles 4 have a diameter of 10-1000 nm.

As shown in fig. 4, in order to achieve the effect of inhibiting drugs (the polymer nanoparticles are loaded with drugs that inhibit the growth of endothelial cells), the surface of the nitinol alloy can be coated; the drug-loaded nanoparticle 4 includes: the filter element comprises drug particles 41 (the polymer nanoparticles are loaded with drugs for inhibiting the growth of endothelial cells), an inner shell 42 and an outer shell 43, wherein the inner shell 42 wraps the outside of the drug particles 41, the outer shell 43 wraps the outside of the inner shell 42, and the outer shell 43 is coated and connected on the surface of the filter wire 3.

Preferably, the outer shell 43 is composed of any one or two or more of polylactic-co-glycolic acid (PLGA), polycaprolactone, and polylactic-glycolic acid.

Preferably, the inner shell 42 is composed of one or two or three of butyl stearate, polylactic acid-glycolic acid copolymer, polyallylamine, and polyethyleneimine.

Preferably, the drug particles 41 are any one or two or three or four of a fibroblast growth factor receptor inhibitor, recombinant human vascular endostatin, paclitaxel and 5-fluorouracil.

In one embodiment, the preparation method of the drug-loaded nanoparticle 4 is to adopt an O/W homogeneous emulsification method for preparation:

the method comprises the following steps:

preparing a solution of the medicinal granule components with the concentration of 1-8 percent g/ml;

dissolving the polylactic acid-glycolic acid copolymer in dichloromethane to form a polylactic acid-glycolic acid copolymer oil phase;

dispersing the medicine granule component solution and butyl stearate in the polylactic acid-glycolic acid copolymer oil phase to prepare a medicine-containing oil phase;

adding 0.1-1% polyvinyl alcohol solution into the oil phase containing medicine;

centrifuging and homogenizing at 1000-;

adding a rotor, and magnetically stirring for 4 hours;

centrifuging and collecting the microsphere solution;

washing with deionized water for three times to remove residual polyvinyl alcohol solution and the medicine adsorbed on the surfaces of the microspheres;

transferring the concentrated microsphere solution into a penicillin bottle;

freeze-drying by a freeze dryer to prepare the drug particles 41 containing the inner shells 42;

dripping the medicinal granules 41 containing the inner shell 42 into a colostrum solution formed by dichloromethane solution containing 5-20% of the raw material of the outer shell under ultrasonic conditions; dropwise adding 0.05-2% carboxymethyl chitosan solution serving as an external water phase into the primary emulsion solution under the ultrasonic condition to obtain a multiple emulsion solution;

volatilizing the organic solvent in the multiple emulsion solution for 1-8 hours under the condition of electromagnetic stirring, and then centrifuging, washing and freeze-drying to obtain the solidified drug-loaded nanoparticles 4.

In one embodiment, the method for coating the drug-loaded nanoparticles 4 on the surface of the filter wire 3 to obtain the nickel-titanium metal filter wire comprises the following steps:

carrying out surface mechanical polishing treatment on the nickel-titanium metal filter wire;

cleaning with ultrasonic in methanol solution for 1-20 min;

washing with deionized water, and drying with compressed air;

placing the dried nickel-titanium metal filter wire in a steady-state electron cyclotron resonance plasma generating device, and regulating the vacuum degree to 1-10 multiplied by 10^-3Pa, keeping for 10-30 min;

introducing diethylene glycol dimethyl ether, keeping the air pressure at 10-50 Pa, keeping the frequency of microwave plasma at 1-5 GHz, and stopping reaction for 1-20 min; obtaining the nickel-titanium metal filter wire with a large number of chemical bonds of C ═ O, O-C ═ O and O-CO-O on the surface;

coating the drug-loaded nanoparticles 4 on the surface of the nickel-titanium metal filter wire in a chemical bond combination mode through copolymerization reaction; obtaining the nickel titanium metal filter wire coated with drug-loaded nano-particles for inhibiting the adhesion and growth of endothelial cells.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.

Claims (10)

1. A venous filter, comprising: the filter element comprises a recovery element (1), a connecting element (2) and a plurality of filter wires (3), wherein the end parts of the filter wires (3) are fixed in the connecting element (2), and the other side of the connecting element (2) is connected with the recovery element (1);

the connector (2) comprises: a filter wire fixing member (21); the end part of the filter wire (3) is fixedly connected with a filter wire fixing part (21), and the filter wire fixing part (21) is detachably connected with the recovery member (1).

2. A venous filter as claimed in claim 1, characterised in that the connector (2) further comprises: a connecting hook (22); the filter wire fixing piece (21) is detachably connected with the recovery piece (1) through a connecting hook (22);

one end of the connecting hook (22) is connected with the recovery piece (1), and the other end of the connecting hook (22) is detachably connected with the filter wire fixing piece (21).

3. A venous filter as claimed in claim 2, characterized in that the coupling hook (22) comprises: an upper bent part (221), a connecting part (222), and a lower bent part (223); the upper bending part (221), the connecting part (222) and the lower bending part (223) are integrally formed in sequence;

the upper bending part (221) at the upper end of the connecting hook (22) is connected with the recovery part (1), and the connecting part (222) is connected with the filter wire fixing part (21) in a sliding manner; the lower bending part (223) is provided with a cutting edge towards one side of the connecting part (222), so that the recovery part (1) pulls the connecting hook (22) to cut the filter wire fixing part (21) and separately connects the hook (22) and the filter wire fixing part (21).

4. The venous filter as claimed in claim 3, characterized in that the filter wire fixing member (21) is a polymer absorbable wire, the polymer absorbable wire is wound and bound on the end of the filter wire (3), and the other end of the polymer absorbable wire is wound and sleeved on the connecting part (222) of the connecting hook (22).

5. A venous filter as claimed in claim 4, characterised in that the recovery member (1) comprises: the recycling device comprises a recycling shell (11) and a recycling head (12), wherein one end of the recycling shell (11) is of a sealing structure; one end of the recovery head (12) is provided with a recovery connecting structure, and the other end of the recovery head (12) is fixedly connected with the outer side of the sealing end of the recovery shell (11);

the filter wire fixing piece (21) is arranged inside the recycling shell (11), and an upper bending portion (221) of the connecting hook (22) extends out of a sealing end of the recycling shell (11).

6. The venous filter according to claim 5, characterized in that the connecting hook (22) is of a Z-shaped structure, the lower bending part (223) is bent towards the center of the recovery shell (11), one end of the upper bending part (221) far away from the connecting part (222) is integrally formed with an auxiliary hook (224) towards one side close to the recovery shell (11), and the auxiliary hook (224) is in relatively limited connection with the outer wall of the recovery shell (11).

7. A venous filter as claimed in claim 2, characterized in that the coupling hooks (22) are provided in 1-4 numbers.

8. A venous filter as claimed in claim 7, characterised in that the coupling hooks (22) are arranged in 2, symmetrically arranged with respect to the coupling hooks (22) of the recovery casing (11).

9. The venous filter according to any of the claims 1 to 8, characterized in that the outer surface of the filter filaments (3) is modified and coated with drug-loaded nanoparticles (4) that inhibit the adhesion growth of endothelial cells.

10. The venous filter of claim 9, characterized in that the drug-loaded nanoparticles (4) comprise: the filter element comprises a drug particle (41), an inner shell (42) and an outer shell (43), wherein the inner shell (42) wraps the outside of the drug particle (41), the outer shell (43) wraps the outside of the inner shell (42), and the outer shell (43) is coated and connected on the surface of the filter element (3).

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