CN114681107A

CN114681107A - Filter capable of being implanted into tube cavity

Info

Publication number: CN114681107A
Application number: CN202111589766.4A
Authority: CN
Inventors: 赵向前; 陈奕龙
Original assignee: Shenzhen Kyd Biomedical Technology Co ltd
Current assignee: Shenzhen Kyd Biomedical Technology Co ltd
Priority date: 2020-12-25
Filing date: 2021-12-23
Publication date: 2022-07-01
Also published as: CN217118685U

Abstract

The invention relates to the technical field of implanted medical instruments, in particular to an intracavity implant structure, and particularly relates to a vena cava filter, and particularly discloses an intracavity implant structure and a vena cava filter with the same.

Description

Filter capable of being implanted into tube cavity

Technical Field

The invention relates to the technical field of implanted medical instruments, in particular to an intra-lumen implant, and particularly relates to a vena cava filter.

Background

An implantable medical device is a medical device that can be left in the body for a short or long period of time to support and sustain life, has a potential risk to the human body, and has to be strictly controlled in terms of safety and effectiveness. Expandable implantable medical devices such as vascular stents, vena cava filters, occluders, ventricular volume reduction devices, and the like, can be compressed to an extremely small volume and implanted into a body lumen via an interventional procedure, and the compressed devices are released and expanded at a desired location in the body to achieve a therapeutic effect, such as expansion, support, occlusion, volume reduction of a blood vessel or body lumen, or prevention of circulation of blood clots, and the like.

Whether temporary placement for a short period of time or long-term or lifetime implantation, stringent requirements are placed on the body morphology of the endoluminally implanted compression device after release expansion in vivo, e.g. the longitudinal long axis of the implant should generally be kept in the center of the implanted body lumen, i.e. the implant has a good neutrality, otherwise a reduction or loss of implant function may result.

However, good neutrality effects can be difficult to achieve. A typical case is a parachute-shaped vena cava filter, such as the Gunther Tulip manufactured and sold by William Cook^TMFilter and Celect^TMFilter, related documents such as US5324304A, CN 101031254A. Such filters are essentially self-expanding umbrella filters constructed from elongated supports arranged or woven to block thrombus-passing filters in the vein, at least one end of the elongated support being gathered in the central position of the umbrella, and usually also having a release or recovery portion, such as a recovery hook, for releasing or recovering the umbrella in cooperation with a recovery device such as a sheath.

The parachute-shaped vena cava filter lacks effective limit near the recovery hook, and the probability of inclination of the filter during and during the implantation of the filter is high. The inclination of the filter is defined as that the included angle between the longitudinal axis of the filter and the central longitudinal axis of the vena cava is more than 15 degrees, the serious inclination of the filter causes the recovery hook to be attached to the wall of the vena cava or to be adhered to the vena cava, the umbrella shape is unfolded unevenly, and the like, so that the filter cannot be recovered, the thrombus filtering effect is reduced, perforation and other serious events are caused. The cause of the filter tilt may be related to factors such as the pulsation of the main venous vein, gastrointestinal motility, the anatomical morphology of the inferior vena cava itself, and the location of the filter placement.

Improved filter constructions have been disclosed, for example in patent publications US20100049239a1, WO2018120414a1, CN105193521A, CN102470028A, which add a stop mechanism in the vicinity of the recovery hook, with improved filter inclination and increased neutralisation. However, these improved filter structures still have some drawbacks, such as that the limiting mechanism is usually formed by rods arranged on the filter, which, when the rods of such limiting mechanism are arranged longer or in a larger number, will contribute to an increase of the neutrality-inducing effect, while at the same time will significantly increase the difficulty of filter release, in particular, more rods will cause the filter release attitude control and adjustment to be more complicated, the positional deviation of the first released rod may cause the positional deviation of the rear release rod to be amplified, and the larger the axial distance of the two rods along the filter, the more unavoidable. In another typical case, when the delivery sheath carrying the filter is not coaxial with the lumen of the vein, the rod in each direction is released from the delivery sheath into the lumen of the vein at different extension spaces, and the rod on the side close to the inner wall of the lumen is more likely to be laterally deflected or to have abnormal release form. These conditions can lead to tilting of the filter or uneven spatial distribution of the filter rods in the lumen of the venous tube, which can ultimately lead to failure of the filter to recover, reduced thrombus filtration, and various complications.

In addition, the filter has more rods resulting in increased resistance when it is released from the sheath, and the releasing operation in the body cavity will be difficult to use a large force due to its fineness, further resulting in a decrease in controllability of the releasing operation.

The strainer release operation is typically accomplished by operating the delivery cable and the delivery sheath, wherein the strainer is removably attached to the delivery cable and disposed within the delivery sheath, and wherein relative sliding movement of the delivery cable and the delivery sheath is manipulated within the lumen (e.g., inferior vena cava strainer) such that the strainer is released from the delivery sheath and positioned within the lumen, such that the strainer is positioned within the lumen after expansion, and finally the delivery cable is detached. Wherein, it usually also includes the observation and adjustment step before releasing, i.e. the filter is released in the lumen but not disconnected with the delivery steel cable, at this time, the unfolding and positioning posture of the filter in the lumen can be observed in detail through X-ray transmission or radiography, and in the specific case, the filter with the releasing posture and the position not ideal can be retracted into the delivery sheath again. In performing the foregoing steps, it is desirable to slightly adjust the position and attitude of the filter within the lumen by manipulating the delivery cable, which may avoid the aforementioned re-entry of the delivery sheath, and in particular, enable better treatment after implantation of the filter and reduced risk of complications by adjustment.

Disclosure of Invention

The present invention provides an intraluminal implantable filter, in particular an inferior vena cava filter, having features that address or ameliorate one or more of the above disadvantages.

An embodiment of the present invention provides a filter implantable in a lumen, including:

a central member removably connectable with a delivery device for delivering the filter within a lumen;

the anchoring components and the filtering components are arranged at intervals around the central part, are limited by the central part and are used for realizing positioning and filtering in the tube cavity;

the filter having an unconstrained state and an implanted state in which it is radially compressed,

wherein the anchoring member and the filter member are configured to both elastically deform under a compressive load in the implanted state and such that the anchoring member has a radial spring force greater than the filter member at the same radial dimension after compression.

The anchoring member and the filter member have different radial elastic forces, providing the possibility of differential operation for the release control of the different members, in particular the greater radial elastic force of the anchoring member, the spontaneous response during the filter release and posture adjustment operations being the main controlled object, helping the operator to obtain the desired filter positioning position and positioning direction in the lumen by operating the delivery device, for example by operating the delivery device to slightly adjust the filter position and posture when the filter is released in the lumen and not disconnected from the delivery device.

In addition, because the filter element and the anchoring element are limited by the central component, the position and the posture of the filter element with smaller radial elastic force after being released in the tube cavity are influenced by the positioning of the anchoring element, namely, the distribution of the filter element in the tube cavity can be indirectly adjusted, which is more favorable under the condition of more filter elements, and the difficulty of adjusting the filter element is reduced.

It will be appreciated that the above-described anchoring and filtering members are distinguished by their primary function, i.e., anchoring the anchoring member to the lumen wall, primarily to position and orient the filter within the lumen to prevent migration, tilting, and the spatial arrangement of the plurality of filtering members within the lumen primarily serves the desired filtering effect. However, in general, the anchoring member may also have a partial filtering effect due to being placed in the lumen, and the filtering member may also have a partial anchoring or positioning effect due to being pressed against the inner wall of the lumen.

The present invention provides a preferred embodiment wherein the plurality of anchoring members and filter members are arranged in layers in the axial direction of the filter, wherein the plurality of anchoring members are arranged in one layer to form an anchoring portion having an outer edge diameter and the plurality of filter members are arranged in another layer to form a filter portion having an outer edge diameter. The layered arrangement provides more space for the spatial arrangement of the filter elements, so that a better filtering effect is easily obtained, while at the same time the risk of entanglement that may occur between the anchoring element and the filter element is reduced. In addition, the positions and postures of the anchoring components distributed in a single layer are adjusted after the adjusting force is applied are more uniform.

In addition, it is also generally possible to distinguish the relative positions of the anchoring member and the filter member within the lumen, in the direction of blood flow within the implanted lumen, the filter member first responding to the blood flow to achieve a filtering effect.

Wherein, in a further preferred embodiment, said anchoring portion is closer to said central member than said filtering portion. From the nature controlled, the adjustment force can be exerted by more accurate by the anchor member of individual layer distribution, has improved the response conveyor adjustment performance in anchor portion, improves the effect of whole filter gesture and position adjustment.

Typically, the plurality of anchoring structures in the anchoring portion are symmetrically disposed and the plurality of filtering structures in the filtering portion are symmetrically disposed. This makes it possible to make the anchoring portion and the filter portion more uniformly compressed in the inner circumferential direction of the lumen, and the filter insertion more stable.

In a preferred embodiment of the invention, the outer diameter of the anchoring portion is smaller than the outer diameter of the filter portion when the filter is in an unconstrained state. This ensures that the plurality of filter members have sufficient deformation to form and maintain a filter function configuration when the filter is in an implanted state. Moreover, this arrangement allows for greater deformation and displacement of the filter element relative to the anchor element at equivalent diametric dimensions after compression, and minor adjustments to the anchor element may result in correspondingly greater adjustments of the filter element, improving the ability to indirectly manipulate the filter element.

In a preferred embodiment of the present invention, a connecting portion is provided at one end of the central member in the axial direction of the strainer, for connecting with the delivery device; the other end of the central member is provided with a retrieval portion that can be captured by a retrieval device for removing the implanted filter within the lumen. After the filter is implanted into the lumen for a certain period of time, it may be considered to remove the filter from the lumen, and the recovery part and the connection part are in an opposite design to facilitate the recovery operation. Wherein, along the filter axial, anchor portion and filter site are located connecting portion one side of central component has more avoided anchor portion and filter site to the direct interference of retrieving the operation, for retrieving the operation provides bigger intracavity operating space, reduces and retrieves the degree of difficulty.

In an alternative embodiment, the central component is a hub, and the connecting part is a thread arranged on the inner periphery of the hub and can be in threaded connection with the conveying device; the recovery part is a hook-shaped body formed by slotting the hub or a hook-shaped body attached to the hub, and can be captured by a recovery device with a collar.

In a preferred embodiment of the present invention, the anchoring member has a load buffering structure of a curved configuration for buffering a compressive load. When the anchoring member is implanted, the compression load of the filter by the tube cavity is changed, and the load buffering structure can buffer the impact of the compression load on the anchoring member, particularly the position where the anchoring member is limited, so that the fatigue fracture risk of the anchoring member is reduced. On the other hand, the load buffering structure provides more adjustment space for the adjustment of the posture and the position of the anchoring member in the lumen, and particularly can effectively improve the contact mode of the anchoring member and the inner wall of the lumen.

In one embodiment of the invention, the anchoring elements extend substantially in the axial and radial direction of the strainer, but not substantially in the circumferential direction, wherein the curved configuration constitutes a load buffering structure and thus also extends substantially in the axial and radial direction of the strainer.

According to one embodiment of the present invention, the anchoring members and the filtering members are arranged in groups, and the anchoring members and the filtering members in each group are connected by a coupling member, so that the anchoring members and the filtering members in each group form linkage, and the anchoring members and the filtering members in each group can be mutually actuated by the coupling member.

The formation of a linkage between the anchoring member and the filtering member within each group may refer to:

the elastic deformation of the anchoring members within each group actuates the filtering members and the coupling members;

alternatively, or in combination, the elastic deformation of the filtering structures within each set actuates the anchoring members and the coupling members.

Preferably, the anchoring member or the filter member is actuated at least in a radial direction of the filter.

The anchoring member and the filter member are in an actuating relationship, further enhancing the ability to indirectly manipulate the filter member.

It will be appreciated that there is no direct fixed connection between the anchoring members or filtering members of the above groups, which would not result in an actuating effect within the group.

In one embodiment, the anchoring members and the filter members within a group are in a staggered arrangement relative to each other in the circumferential direction of the strainer. In the implanted state, the anchoring member and the filter member within the set provide elastic forces in different radial directions. The staggered arrangement further improves stability within the lumen when the filter is implanted.

In a preferred embodiment of the above filter arrangement, the anchoring means, the filter means and the coupling means are rod-shaped members;

wherein the coupling members extend away from the hub to their ends, the ends of each coupling member further extending to an anchoring member and two filter members which extend further outward than the coupling member, and the extended anchoring member being located between the two filter members.

In a further improvement, the coupling member is provided with a bending part close to the tail end of the coupling member, and an included angle between the tail end direction of the coupling member and the axial center line of the central part after the coupling member passes through the bending part becomes smaller;

the filter members extend to the lower part of the bending part along the axial direction of the filter, and two adjacent filter members led out by two adjacent coupling members extend oppositely. Two adjacent filter members may extend towards each other without making contact, but preferably with a movable contact. For example, in the implanted state, the contact position of two adjacent filter members with respect to each other may vary with load, but a smaller variation in contact position is generally desired.

In a further improvement, the anchor member is substantially coplanar with the coupling member leading therefrom, and the anchor member extends toward the trailing section thereof in a generally U-shaped or V-shaped bent configuration to form a load cushion.

The coupling member sets up the portion of bending, can further improve its inter group anchor member U-shaped or V-arrangement load buffer structure's load buffering effect, make more by the anchor member bear of load, on the one hand, the anchor member can realize more fast applying the response of dynamic load to the intracavity wall, long-term anchoring effect at the implantation state is better, simultaneously, the position change that the filter wholly responded to dynamic load is also littleer, on the other hand, the load that the coupling member bears reduces, make the root of coupling member have lower stress, this root fatigue fracture's that can show the reduction coupling member risk.

In a further development, the end section of the anchoring element is situated axially above the bend in the direction of the strainer and is oriented toward the central part. This may reduce the risk of the anchoring member puncturing the inner wall of the lumen by expansion when the filter is released within the lumen.

In a further refinement, the rod widths of the anchoring member and the filter member are less than the rod width of the coupling member, and the length of the anchoring member is less than the length of the filter member and greater than the length of the coupling member. The relatively larger rod width of the coupling member may improve the stability of the filter configuration in the implanted state and further improve the ability of the anchoring member to buffer loads.

In a preferred embodiment of the filter of the present invention, the anchoring member and the filter member are both non-invasive luminal inner wall structures. Neither the anchoring member nor the filter member have structures that can cause damage to the inner wall of the lumen, common structures that can cause damage to the inner wall of the lumen including, for example, anchors, sharp ends of rods, or hooks.

In a preferred embodiment of the filter of the present invention, the filter is a thrombus filter implantable in the inferior vena cava.

In a preferred embodiment of the filter of the present invention, the anchoring member and the filter member are configured to have different radial compression ratios at the same radial dimension after compression, wherein the anchoring member has a radial compression ratio of less than 30% and the filter member has a radial compression ratio of greater than 50% at a radial dimension of 18-32 mm after compression.

Wherein, the radial compression ratio refers to the ratio of the difference of the radial length change before and after compression to the radial length before compression.

Wherein, and preferably, the anchoring member has a radial elasticity value 2-8 times greater than the radial elasticity value of the filter member.

For example, the anchoring member may have a radial elasticity value of 0.2-0.8 newton, and the filtering member may have a radial elasticity value of 0.05-0.2 newton.

In summary, the present invention provides a filter implantable in a lumen, which has better controllability, facilitates adjustment of the posture and position of the filter in the implanted state in the lumen, and simultaneously, the better structural design helps to improve the neutrality, migration resistance, inclination resistance, fatigue fracture resistance, recyclability, etc. of the filter in the lumen, thereby improving the therapeutic effect and reducing the risk of complications.

In another aspect of the present invention, there is provided another lumen implantable filter, which may include:

the plurality of anchoring members and the plurality of filter members are arranged in layers in an axial direction of the strainer, wherein the plurality of anchoring members are arranged in one layer to constitute an anchoring portion having an outer edge diameter, and the plurality of filter members are arranged in another layer to constitute a filter portion having an outer edge diameter;

the radial supporting force of the anchoring portion is greater than the radial supporting force of the filter portion.

Wherein the number of the anchor members constituting the anchor portion may be not greater than the number of the filter members constituting the filter portion.

Unless otherwise defined, the radial elastic force referred to herein generally refers to the mechanical test results of the individual components, and the radial support force referred to herein generally refers to the force that the anchoring or filtering portion is measured to apply to the lumen or circumferential compression device.

In another aspect of the present invention, there is provided an endoluminal implant construct, which is adapted for use with the aforementioned endoluminal filter, comprising a central portion having a central axis and a functional portion having an outer periphery comprised of a plurality of rods extending outwardly from the central portion, the functional portion outer periphery being compressible about the central axis.

The functional part can be at least used as a positioning structure of the implant, the functional part can be compressed to have elasticity, and the implant can be anchored in a human body cavity, such as a blood vessel, by utilizing the elastic force which the functional part has the tendency to restore to the uncompressed state when in the compressed state. In the anchored state, the central axis may tend to be centered within the body lumen, or the functional portion may conform to the body lumen shape.

At least one rod is provided with a bending part protruding towards the outer side direction of the functional part, the upper part and the lower part of the bending part are respectively provided with an upper branch section and a lower branch section which have different included angles with the central axis, the rod is further provided with a side branch section extending outwards near the bending part or the bending part, and the farthest end of the side branch section, which is far away from the central axis, is positioned between the tail end of the lower branch section and the bending part in a non-compression state.

In an embodiment of the present invention, the side branch section is coplanar with the central axis, two lower branch sections are led out below the bending portion, and the two lower branch sections are respectively located on two sides of the coplanar.

In an embodiment of the present invention, an included angle between the extending direction of the upper branch section and the central axis is greater than an included angle between the extending direction of the lower branch section and the central axis.

In one embodiment of the invention, the side branch section comprises an arc-shaped bending section extending upwards, and the deflection angle of the tail end of the arc-shaped bending section relative to the starting end of the arc-shaped bending section is larger than 90 degrees.

In a preferred embodiment of the present invention, the curvature radius of the arc-shaped curved section gradually increases toward the end thereof.

In a preferred embodiment of the present invention, the side branch section further includes a straight section, and the straight section is substantially parallel to the lower branch section, led out from the bending portion, and transited to the arc bending section.

In a preferred embodiment of the present invention, the number of the lower branch sections is at least two, and the straight sections located therebetween are arranged in the width direction of the rod.

In a preferred embodiment of the present invention, a portion of the curved segment adjacent to the distal end thereof is substantially parallel to the central axis or is approximately parallel to the central axis.

In an embodiment of the present invention, the side branch section further includes a tail section, which is led out from the end of the arc-shaped bent section, the tail section points to the central axis direction, and the rod width of the tail section is smaller than that of other parts in the arc-shaped bent section.

The tail section may have a flanged spherical structure terminating in a spherical or spheroid-like body.

In some embodiments of the invention, the upper branch section has a width greater than the widths of the lower branch section and the side branch section, respectively, and the curved section of the side branch section includes a parallel section substantially parallel to the central axis to form a press contact with the inner wall of the body cavity. The curvature radius of the arc-shaped bending section is gradually increased from the starting end to the tail end of the press-contacting section, a bent tail section extends towards the direction of the central part after the parallel section, and the width of the tail section is smaller than that of other sections in the side branch section. The variation in width can reduce resistance to rod retraction into or release out of the sheath, and the implant's maneuverability in release and retraction is improved. The width of the tail section is processed, so that the bypass section can be effectively prevented from being stuck at the opening of the sheath when being recycled into the sheath, because the central axis of the central part of the implant implanted in the blood vessel is almost impossible to coincide with the central axis of the opening of the sheath when being recycled, and at least some bypass sections are inevitably taken into the opening of the sheath in an inclined posture, which causes the phenomenon that the bypass section is stuck at the opening of the sheath to be high.

In alternative embodiments of the present invention, the endoluminal implant structure may also have one or more of any combination of the following structural features:

the structure I is characterized in that the straight section and the central axis form an included angle;

a second structure, wherein the arc-shaped bending section is internally provided with a lowest point along the direction of the central axis, and the lowest point is positioned between the near end and the far end of the arc-shaped bending section;

and in a third structure, the deflection angle of the far end of the arc-shaped bent section relative to the near end of the arc-shaped bent section is not more than 180 degrees.

And in a fourth structure, the deflection angle of the far end of the side branch section relative to the near end of the side branch section is more than 180 degrees.

In an alternative embodiment of the invention, the rods forming the functional part are not fixedly connected to each other.

It is another aspect of the present invention to provide a vena cava filter having an endoluminal implant structure as set forth above.

Wherein, each rod of function portion evenly distributes along circumference for block the thrombus in the vena cava passes through the function portion.

In one embodiment of the invention, each rod of the functional part leads out two lower branch sections extending in opposite directions from the bending part, and when the functional part is in a compressed state, the adjacent rods are abutted or crossed with each other through the two adjacent lower branch sections, so that the functional part forms a net structure.

The two lower branch sections can improve the supporting performance of the periphery, and the lower branch sections are staggered with the side branch sections, so that the release resistance of the rod can be reduced. The filter can take place endothelialization phenomenon after implanting a period of time in the blood vessel, and the endothelium climbs the pole of covering the implant for the filter is retrieved the degree of difficulty and is big, retrieves the damage increase to the blood vessel, can not retrieve even. The two lower branch sections are not fixedly connected, so that the lower branch sections have larger freedom degree, and are easier to extract from endothelial tissues, the damage to blood vessels is reduced, and meanwhile, the contact of the two lower branch sections can also improve the support capability and the shape stability of the rod, so that the filter can be more stably kept at the position released by a fixed point in the blood vessel according to the required shape, and the filter is prevented from migrating.

In one embodiment of the invention, two lower leg sections adjacent between said adjacent rods abut away from their ends in the non-compressed state.

In still another aspect of the present invention, there is provided an endoluminal implant having a further structure or an endoluminal implant having the same, which is applicable to the above-described filter implantable intraluminal device, comprising a central portion having a central axis and a functional portion having an outer periphery and consisting of a plurality of rods extending outwardly from the central portion, the functional portion being compressible.

In the structure of the intracavity implant body, when in a non-compression state, the functional part at least comprises a first periphery, a second periphery and a third periphery which are formed by arranging flanges or free ends of a plurality of rods around the central axis, the first periphery, the second periphery and the third periphery are sequentially arranged from the central part to the outside and are not coplanar with each other, and the first periphery and the second periphery are closer to the central part than the third periphery along the direction of the central axis;

the flange or free end of the rod may be pressed to move towards the central axis, and the second and third peripheries may be pressed to positionally retain the implant in a first position within the cavity in which it is implanted;

any one or more of the flanges or free ends forming the first outer perimeter, when compressed, may cause the implant to be positionally retained towards the first position within the cavity in which it is implanted.

Obviously, said flange is meant to be directed towards the outer side of said functional part, in order to provide a possible support site in the anchored state of the implant.

The second periphery and the third periphery form two layers of supporting positions of the functional part distributed along the long axis direction of the cavity, the two layers of supporting positions can be contacted with the inner wall of the cavity implanted by the implant, and relative to the non-compressed state, the second periphery and the third periphery are pressed by the inner wall of the cavity, can resist the inclination of the central part or the central axis to the direction of the inner wall of the cavity, and keep a certain distance between the central part and the inner wall of the cavity to form a desired first posture. When the support of the flange or free end of any one or more of the rods of the second periphery is lost due to various factors, such as the flange being displaced laterally from the free end, the support is lost or weakened, and the flange or free end of the rod of the first periphery in the vicinity of the support site can abut against the inner wall of the cavity to form a second posture, the central portion is prevented from adhering to the wall against the inclination of the central portion or the central axis to the inner wall of the cavity in the lateral direction of the displaced support site, i.e., the implant can keep the second posture as close to the first posture as possible.

In one embodiment, the number of flanges or free ends forming the first periphery is not less than the number of flanges or free ends forming the second periphery, and at least one to one. Wherein the flange or free end constituting the first outer periphery and the corresponding flange or free end constituting the second outer periphery may be located substantially in the same radial direction. For example, a preferred embodiment of the one-to-one correspondence may mean that one flange or free end constituting the first outer periphery and the other flange or free end constituting the second outer periphery corresponding thereto are substantially in the same radial direction.

In one embodiment, the first outer periphery is located between the second outer periphery and the third outer periphery in the direction of the central axis. Or the second outer periphery is located between the first outer periphery and the third outer periphery in the central axis direction.

In one embodiment, the first outer periphery is formed by a flange of the rod.

Alternatively, either periphery may optionally be formed by a flange or free end. For example, both the third and second peripheries may be constituted by the free end, or the third periphery may be constituted by the free end and the second periphery may be constituted by the flange.

The rods constituting the outer periphery may include at least a first array rod and a second array rod.

In one embodiment, the third perimeter is formed by an arrangement of free ends of the first array of rods and the second perimeter is formed by an arrangement of free ends or flanges of the second array of rods.

In one embodiment, the third periphery is formed by an arrangement of free ends of the first array of stems, the first array of stems further being provided with branches, and the second periphery is formed by an arrangement of free ends or flanges of the branches of the first array of stems.

In a further development, the first array rods are further provided with flanges, the first periphery being constituted by the flanges of the first array rods. For example, the first array rods each have a bent portion, the first array rods form an included angle at the bent portion at a front section and a rear section of each bent portion, and the bent portions of the first array rods form the flange.

In one embodiment, the rod forming the free end or flange of the second periphery has a curved section extending in a direction away from the third periphery, the terminal end or protruding end of the curved section forming the free end or flange of the second periphery.

Preferably, the second outer periphery is radially close to the first outer periphery.

Optionally, the first periphery, the second periphery and the third periphery are all located on the same side of the central portion.

Preferably, the flange or the free end has a smoothly curved surface, and can be brought into contact with the inner wall of the cavity in which the implant is implanted through the smoothly curved surface.

Preferably, the number of flanges or free ends constituting the third outer periphery is greater than the number of flanges or free ends constituting the second outer periphery.

In a further improvement, the number of the flanges or free ends constituting the third outer periphery is twice the number of the flanges or free ends constituting the second outer periphery, and the flanges or free ends constituting the third outer periphery are distributed in pairs, each pair of the flanges or free ends constituting the third outer periphery and the flanges or free ends constituting the second outer periphery being distributed in a staggered manner in the circumferential direction of the central axis.

Preferably, each rod of the functional part is made by integrally cutting a pipe and then shaping.

In another aspect of the present invention, there is provided a vena cava filter having the endoluminal implant structure as described above, wherein the rods of the functional section are uniformly distributed along the circumferential direction for blocking thrombus in the vena cava from passing through the functional section.

In another aspect of the present invention, there is also provided a retrievable endoluminal implant construct or a retrievable endoluminal implant having the construct, including a central portion having a central axis and a functional portion formed by a plurality of rods extending outwardly from the central portion arranged around the central axis, the implant being positionally retainable within a chamber in which the implant is implanted by compression of the functional portion by an endoluminal wall.

Wherein at least one rod includes an arcuate curved segment having a radius of curvature that increases from its proximal end proximate the central portion to its distal end.

In one embodiment of the invention, the radius of curvature is gradually increased, and the more the arc-shaped curved section tends to be straight towards the distal direction, the less the resistance when the sheath is retracted.

In one embodiment of the invention, the curved segment is substantially parallel to the central axis or is approximately parallel to the central axis adjacent to its distal end.

In one embodiment of the invention, the shaft further continues with a tail section at the distal end of the arcuate bend section.

In one embodiment of the invention, the tail section is parallel to the central axis or curved in the direction of the central axis.

In one embodiment of the invention, the end of the rod is a spherical or similar spherical body having a flanged spherical surface structure.

In one embodiment of the invention, the rod as a whole has a tendency to decrease in width towards its distal end.

In one embodiment of the invention, the end bulb or similar bulb of the rod has a diameter greater than the rod width of its proximal segment. For example, the rod width of the tail section is less than the rod width of the arcuate bend section.

In an embodiment of the present invention, the rod is further provided with a straight section at a proximal side of the arc-shaped curved section, the rod extends from the straight section to the arc-shaped curved section, and the straight section forms an included angle with the central axis.

In one embodiment of the invention, the arcuate curved segment has a lowest point therein in the direction of the central axis, the lowest point being located between the proximal and distal ends of the arcuate curved segment.

In one embodiment of the invention, the distal end of the curved segment is deflected by an angle greater than 90 degrees relative to its proximal end.

It is another aspect of the present invention to provide a venal caval filter having the aforementioned retrievable endoluminal implant construct.

In summary, the endoluminal implant structure according to embodiments of the present invention, and an implantable intraluminal filter, such as an inferior vena cava filter, having the same, may have improved properties in terms of neutrality, transportability, safety, and ease of handling.

In embodiments of the invention, endoluminal implants, such as filters implantable in lumens of a vessel, may be used as a retrievable device, and may have the effect of longer implantation period, higher success rate of retrieval, less damage to the vena cava, and the like.

Drawings

FIGS. 1 and 2 are schematic views of a single rod of two implant configuration embodiments of the present invention;

FIGS. 3-9 are schematic views of two symmetrical rods of different implant configuration embodiments of the present invention;

FIGS. 10-12 are central axis orientation views of three implant configuration embodiments of the present invention;

FIGS. 13 and 14 are schematic views of a preferred embodiment of the vena cava filter of the present invention in different orientations, respectively;

FIG. 15 is an enlarged view of a portion of FIG. 13;

FIGS. 16 and 17 are graphs illustrating two different effects of a preferred embodiment of a vena cava filter of the present invention after release from an implanted chamber, respectively;

FIGS. 18 and 19 are finite element analysis graphs of simulated forces after implantation in a lumen for two embodiments of vena cava filters, respectively;

fig. 20a, 20b, and 20c are different release profiles for implantation in the inferior vena cava following delivery of the preferred embodiment of the vena cava filter through the femoral vein of a subject, showing the delivery cable still attached to the vena cava filter, wherein the portion of the vena cava filter shown in fig. 20a releases the delivery sheath, the filter element of the filter remains constrained by the delivery sheath and is not released, fig. 20b and 20c show the complete release of the delivery sheath from the vena cava filter, and fig. 20b shows that one of the anchor elements of the filter is not released in the desired configuration in the inferior vena cava, requiring adjustment.

In the drawings, reference numerals are explained as follows:

1. a central portion; 2. a first array of rods; 21. an upper branch section; 211. a bending part; 22. 221, 222, a lower branch section; 23. a bypass section; 31. a first outer periphery; 32. a second outer periphery; 33. a third outer periphery; 4. a second array bar; 5. the inner wall of the cavity.

Detailed Description

One type of prior art endoluminal implant structure includes a central portion having a central axis and a functional portion having a periphery formed by a plurality of bars extending outwardly from the central portion, the functional portion periphery surrounding the central axis and being compressible by the luminal inner wall toward the central axis such that the implant is positionally retained within the lumen in which it is implanted. An exemplary such implant structure is described in WO2017186025A1, the inventor of the present application, which is incorporated herein in its entirety. The implant in the stronger compression state has small shape and volume and can be placed in a sheath tube and conveyed in a human body cavity channel through the sheath tube, the implant is released from the sheath tube at a position where the implant needs to be placed through operation of an operator, the implant in the stronger compression state expands and tends to be in a non-compression state, the functional part rod of the implant is far away from the central axis and expands and presses against the inner wall of an implanted cavity, the plurality of rods support the circumferential direction of the implant, and at the moment, the functional part expands and keeps in the weaker compression state relative to the stronger compression state so as to position and keep the implant in the implanted cavity.

However, the above description is not limiting, and the endoluminal implants disclosed in CN1399530A, CN1842354A, CN105208947A, etc. have similar structures.

The embodiments of the present invention will be described in further detail with reference to the drawings and the detailed description.

Endoluminal implant set

An object of the present invention is to provide an improved endoluminal implant structure, in which the functional section includes at least first, second and third

outer circumferences

31, 32 and 33 formed by flanges or free ends of a plurality of rods arranged around a central axis when in a non-compressed state, the first, second and third

outer circumferences

31, 32 and 33 being sequentially arranged outward from the central section 1 and not coplanar with each other, the first and second

outer circumferences

31 and 32 being closer to the central section 1 in the central axis direction than the third outer circumference 33;

the flange or free end of the stem may be pressed to move towards the central axis, and the second outer periphery 32 and the third outer periphery 33 may be pressed to hold the implant in a first position within the cavity in which it is implanted;

any one or more of the flanges or free ends forming the first outer perimeter 31, when compressed, will allow the implant to be held in position as it approaches the first position within the cavity in which it is implanted.

Wherein the flange faces in an outer direction of the functional portion.

The flange according to the embodiment of the present invention may be the bending portion 211 of the rod facing the outside direction of the functional portion, referring to fig. 1 to 9, or may be the farthest end of the arc-shaped bending section from the central axis, referring to fig. 15, where the curvature radius is D2. However, without limitation, one skilled in the art may select other types of flanges that may serve as support sites for the implant to stop and support in contact with the inner walls of the implanted cavity. The flange is preferably the bending part 211 of the rod, and referring to fig. 1-9 or fig. 13, the bending part 211 has a non-arc bending, so that the rod forms a relatively fixed included angle above and below the bending part 211, which makes it possible to reduce the transmission of the compressive force to the root of the rod when the end of the rod is pressed by the inner wall of the cavity, because the included angle of the bending part 211 can be reduced due to the pressing of the end of the rod, which plays a role in buffering or reducing the force transmitted to the root of the rod. Meanwhile, the lower leg of the rod led out below the bent portion 211 provides the distal end of the rod with greater elastic restoring force due to the smaller angle of the bent portion 211, thereby providing stronger support and positioning of the implant within the implantation chamber.

With continued reference to fig. 15 and 16, the segment having a radius of curvature D2 may be a press-contact segment substantially parallel to or inclined to be parallel to the central axis and may press-contact the inner wall of the implanted cavity to support or bolster the positioning of the implant. The curvature radius of the whole arc-shaped bending section is gradually increased from the starting end to the tail end of the pressing contact section. The inclined part is parallel to the central axis, and the included angle between the press contact section which can be basically a straight line and the central axis is not more than 15 degrees. This kind of setting, when the implant was retrieved to existing the being favorable to, the pressure touched the section and was taken in and retrieve the sheath pipe, reduces the body cavity inner wall, retrieves the recovery resistance to implant deformation that the sheath mouth produced, when being favorable to implantation state again, the pressure touched the section and provides the contact with the great area of body cavity inner wall, improves the stable effect of anchor.

Referring to fig. 10-12, three implant structural embodiments of the present invention are shown, each having a first outer perimeter 31, a second outer perimeter 32, and a third outer perimeter 33 of the flange or free end of the stem, with radii a, b, and c, in that order. The shape of each rod constituting the functional part of the implant of fig. 12 may be any one of fig. 7 to 9, and the shape of each rod constituting the functional part of the implant of fig. 10 and 11 may be any one of fig. 1 to 6. The main difference between the implant functions of fig. 10 and 11 is the number and shape of the lower branch of the stem.

The second outer periphery 32 and the third outer periphery 33 constitute two layers of support sites of the functional part distributed along the long axis direction of the cavity, and can be contacted with the inner wall of the cavity implanted by the implant, and the second outer periphery 32 and the third outer periphery 33 can resist the inclination of the central part 1 or the central axis to the direction of the inner wall of the cavity by the pressure of the inner wall of the cavity in a non-compressed state, and keep a certain distance between the central part 1 and the inner wall of the cavity to form a desired first posture. When the support of the flange or free end of any one or more of the rods of the second outer circumference 32 is lost due to various factors, for example, the flange or free end is displaced laterally to lose or weaken the support, the flange or free end of the rod of the first outer circumference 31 in the vicinity of the support site may abut against the inner wall of the cavity to form a second posture, and the central portion 1 is prevented from abutting against the cavity wall against the inclination of the central portion 1 or the central axis toward the inner wall of the cavity in the lateral direction of the displaced support site, that is, the implant may maintain the second posture as close to the first posture as possible.

However, the above description is not restrictive, and the implant can directly assume the second posture after being released through the sheath in the cavity, but not assume the first posture, and in this case, the first posture can be the ideal implant implantation state desired by the operator. For example, the implant is released in the case of poor overlap of the sheath with the cavity along the long axis.

As a non-limiting example, another possibility is that peristaltic movement, contraction, etc. of the cavity causes a change in the position or shape of the implanted implant from an initial first posture to a second posture.

Fig. 13 and 14 show a preferred embodiment of an implant according to the invention, which is similar to fig. 11 in a top view along the central axis of the central part 1, with three peripheries, fig. 16 and 17 showing two positions of the implant in the implanted cavity, the position of the implant shown in fig. 16 being generally desirable, at least one of the support sites of the second periphery 32 in fig. 17 failing due to lateral offset, and the nearby bent part 211 of the rod constituting the first periphery 31 acting as a support site, the position of the implant avoiding a more excessive tilt of the central part 1 or central axis, keeping the central part 1 at a suitable distance from the wall of the cavity.

As a preferred embodiment, the number of flanges or free ends constituting the first periphery 31 is not less than the number of flanges or free ends constituting the second periphery 32, and at least one-to-one correspondence. Fig. 10 and 11 show a corresponding manner in the radial direction of the periphery, in which the number of flanges or free ends constituting the first periphery 31 is equal to the number of flanges or free ends constituting the second periphery 32, and the two corresponding flanges or free ends of the periphery are located in substantially the same radial direction, which gives the first periphery 31 a better complementary support effect for the support sites, a more precise complementary support for the failure sites of the second periphery 32, and a smaller angle of inclination of the filter which can thus be controlled. Fig. 12 shows another non-radial correspondence between the flanges or free ends of any two adjacent second peripheries 32 for a flange or free end of a first periphery 31. Wherein the number of flanges or free ends of the first outer circumference 31 is equal to the number of flanges or free ends of the second outer circumference 32 in fig. 10-12.

As a preferred embodiment, the first periphery 31 is located between the second periphery 32 and the third periphery 33 in the direction of the central axis, see the distribution of the respective peripheral radii shown in fig. 1 and 2. In other alternative embodiments, the second outer periphery 32 is located between the first outer periphery 31 and the third outer periphery 33 in the direction of the central axis, such as in fig. 5.

The third outer periphery 33, the second outer periphery 32 and the first outer periphery 31 may each be constituted by free ends of rods, for example, the first array rod 2, the second array rod 4 and the third array rod in turn.

In a preferred embodiment, the first periphery 31 is constituted by a flange of the rod, and both the third periphery 33 and the second periphery 32 are constituted by free ends, or the third periphery 33 is constituted by a free end and the second periphery 32 is constituted by a flange. For example, the third outer periphery 33 is formed by an arrangement of free ends of the first array of rods 2 and the second outer periphery 32 is formed by an arrangement of free ends or flanges of the second array of rods 4, each of which may have the shape of any of FIGS. 7-9, with reference to FIG. 12; for another example, the third outer periphery 33 is formed by an arrangement of free ends of the first array rod 2, the first array rod 2 is further provided with branches, the second outer periphery 32 is formed by an arrangement of free ends or flanges of the branches of the first array rod 2, and referring to fig. 10 or 11, the shape of the first array rod 2 and its branches may be any of fig. 1-9.

Wherein the first array rod 2 may also be provided with a flange, the first periphery 31 being constituted by the flange of the first array rod 2. For example, the first array rods 2 each have a bending portion 211, the first array rods 2 form an included angle at the bending portion 211 at the front and rear sections of the respective bending portion 211, and the bending portions 211 of the first array rods 2 form a flange, refer to fig. 1-6.

Wherein the free end or flange forming the second periphery 32 is provided in the stem with a curved section extending in a direction away from the third periphery 33, the end or protruding end of the curved section forming the free end or flange of the second periphery 32. Referring to fig. 1 to 4 and 6, the first array rod 2 has branches, from the upper branch section 21, extending to the lower branch section 22 and the side branch section 23, wherein the side branch section 23 has a curved section, and the second outer circumference 32 can be formed by the end of the curved section as a free end or by the outermost protruding end of the curved section as a flange according to the shape of the curved section.

In a preferred embodiment, the second outer periphery 32 is radially close to the first outer periphery 31. I.e. the distance in the radial direction between the first 31 and second 32 outer peripheries may be smaller than the distance in the radial direction between the second 32 and third 33 outer peripheries.

Alternatively, the first 31 and second 32 peripheries are located on either side of the central portion 1 and the third periphery 33 is located on one of the sides. Preferably, however, the first 31, second 32 and third 33 peripheries are all located on the same side of the central portion 1.

In a preferred embodiment, either the flange or the free end has a smooth curved surface and can contact the inner wall of the cavity in which the implant is implanted via the smooth curved surface.

In a preferred embodiment, the number of flanges or free ends constituting the third outer periphery 33 is greater than the number of flanges or free ends constituting the second outer periphery 32. For example, in the implant of fig. 11, the first array of rods 2 is divided into two

lower leg portions

221, 222 from the bent portion 211, and the adjacent lower leg portions of two adjacent first array of rods 2 may be in contact but not fixedly connected, as shown in fig. 12, 16 or 19. At this time, the number of the flanges or free ends constituting the third outer periphery 33 is twice the number of the flanges or free ends constituting the second outer periphery 32, and the flanges or free ends constituting the third outer periphery 33 are distributed in pairs, each pair of the flanges or free ends constituting the third outer periphery 33 and the flanges or free ends constituting the second outer periphery 32 being staggered in the circumferential direction of the central axis, see fig. 14.

The rods of the functional part of the implant are preferably made by integrally cutting a pipe and shaping. The tubular product can be made of shape memory materials such as stainless steel, nickel-titanium alloy and the like, and the design shape of the non-compression state is obtained through heat setting.

Levers forming the functional part

In the embodiment of the partial implant of the invention, at least one of the plurality of rods forming the functional part is provided with a bending part 211 protruding towards the outer side direction of the functional part, the upper part and the lower part of the bending part 211 are divided into an upper branch section 21 and a lower branch section 22 with different included angles with the central axis, the rod is also provided with a side branch section 23 extending outwards near the bending part 211 or the bending part 211, and the farthest end of the side branch section 23 away from the central axis is positioned between the tail end of the lower branch section 22 and the bending part 211 in a non-compression state.

Taking fig. 1 and 2 as an example, two types of rods constituting the functional part are shown, in which the distance from the central axis of the aforementioned farthest end of the side branch 23 is b, the distance from the central axis of the bent part 211 is c, and the distance from the central axis of the end of the lower branch 22 is a, and it is apparent that a > b > c in the non-compressed state. The side branch section 23 in this embodiment includes an upwardly extending arcuate curved section. The flange formed at the tail end or the outermost side end of the arc-shaped bending section can be propped against the inner wall of the implanted cavity body in the cavity to play a supporting role.

The rod with the bending part 211 is implanted in the cavity, and two support points with functional parts distributed along the long axis direction of the cavity are formed by the most far end of the side branch section 23 and the tail end of the lower branch section 22, so as to resist the inclination of the central part 1 to the inner wall of the cavity in the side direction of the rod, and keep a certain distance between the central part 1 and the inner wall of the cavity, see the embodiment of fig. 12.

When the side branch 23 is in its non-compressed state, laterally influenced by various factors, and its function as a support point may be lost, the bent portion 211 of the rod may abut against the inner wall of the cavity to resist the inclination of the central portion 1 toward the inner wall of the cavity in the direction of the side on which the rod is located. At this time, the bending part 211 and the lower branch 22 can be integrally abutted against the inner wall of the lumen, the support area of the rod is increased, the support of the functional part is more stable, but the unit pressure on the inner wall of the lumen is weak, so that the inner wall of the blood vessel can be prevented from being crushed or punctured, see the embodiment of fig. 17.

The side branch section 23 can be arranged to be led out from the bent part 211 of the rod, see fig. 1 and 5, the side branch section 23 shown in fig. 1 is an arc-shaped bent section extending upwards, and the side branch section 23 shown in fig. 5 is a straight section extending downwards.

Alternatively, the bypass portion 23 is provided so as to be drawn out from the vicinity of the bent portion 211 of the lever.

In one embodiment, the side branch section 23 is derived from the upper branch section 21. referring to fig. 2 and 4, the side branch section 23 shown in fig. 2 may be an upwardly extending curved section, and the side branch section 23 shown in fig. 4 is a downwardly extending curved section.

In another embodiment, the side branch 23 may be drawn from the lower branch 22, see fig. 3 and 6.

Those skilled in the art can select different styles of the side branch segment 23 according to the requirement, and the invention is not limited to the embodiment.

The structure and shape of the rod shown in fig. 6 is a preferred embodiment, the rod having an upper leg 21 leading from the central portion 1 and a lower leg 22 leading via a bend 211. The side branch section 23 is led out from the lower branch section 22 and comprises an arc-shaped bent section. The end of the side branch section 23 is deflected by an angle of more than 180 degrees with respect to its starting end, and its end points in the direction of the central axis.

In a further preferred embodiment, the curved section has a radius of curvature which increases towards its end. Referring to fig. 13 and 15, the curved section in fig. 15 is formed by three sections, and the radius of curvature of the curved section is sequentially D1, D2 and D3, and the curved section is sequentially increased, so that the side branch section 23 can be attached to the vessel wall as much as possible. On the one hand, the side branch 23 may have a shorter length than the central portion 1, leading from the vicinity of the bent portion 211, and thus may have a greater resistance to deflection, and on the other hand, the gradual increase in the radius of curvature may cause the side branch 23 to contact the blood vessel wall in a line contact rather than a point contact.

The flange formed at the tail end or the outermost side end of the arc-shaped bending section can be propped against the inner wall of the implanted cavity in the cavity to play a supporting role. The rod with the bending part 211 is implanted in the cavity, and two support points with functional parts distributed along the long axis direction of the cavity are formed by the most far end of the side branch section 23 and the tail end of the lower branch section 22, so as to resist the inclination of the functional parts to the side direction of the rod on the inner wall of the cavity and keep a certain distance between the central part 1 and the inner wall of the cavity, as shown in the embodiment of fig. 16. When the side branch section 23 is in its side of non-compressed state, which is affected by various factors, its function as a support point may be lost, and the bent portion 211 of the rod may abut against the inner wall of the cavity to resist the inclination of the functional portion to the inner wall of the cavity in the direction of the side of the rod. At this time, the bending part 211 and the lower section 22 can be integrally abutted against the inner wall of the cavity, the support area of the rod is increased, the support for the functional part is more stable, but the unit pressure on the inner wall of the cavity is weak, and the inner wall of the blood vessel can be prevented from being crushed or punctured, as shown in the embodiment of fig. 17.

In a further improvement, referring to fig. 13 and 15, the side branch segment 23 further includes a straight segment L, and the straight segment is substantially parallel to the lower branch segment 22, led out by the bending portion 211, and transited to an arc-shaped bending segment. The lower branch section 22 may be one, two or more, and may be set as required by those skilled in the art. When there are at least two lower branch segments 22, in a preferred embodiment, the side branch segment 23 is located between the two

lower branch segments

221, 222, and the straight segment of the side branch segment 23 and the lower branch segment are arranged in the pole width direction.

Based on the above description, the side branch section 23 may be selected to be coplanar or non-coplanar with the central axis. The non-coplanar bypass sections 23 may be more difficult to release and retrieve.

The side branch 23 is shown in figure 10 to be coplanar with the central axis, with the bend 211 of the bar in which the side branch 23 is located leading out of the lower branch 22. The side branch section 23 shown in fig. 11 is coplanar with the central axis, the bending part 211 of the rod where the side branch section 23 is located leads out two

lower branch sections

221, 222, and the two

lower branch sections

221, 222 are respectively located at two sides of the coplanar.

The implant functional part of fig. 10 and 11 has the third outer circumference 33 formed by the tips of the lower branch sections of 6 first array rods 2 arranged at equal intervals around the central axis, the second outer circumference 32 formed by the farthest ends of the side branch sections 23 of 6 first array rods 2 arranged at equal intervals around the central axis, and the first outer circumference 31 formed by the bent sections 211 of 6 first array rods 2 arranged at equal intervals around the central axis. Whereas the implant function of fig. 12 is composed of 6 first array rods 2 alternating circumferentially with 6 second array rods 4.

In the uncompressed state, the diameter of the third outer periphery 33 is preferably 1.5 to 4 times the diameter of the second outer periphery 32, and the second outer periphery 32 is radially closer to the first outer periphery 31.

The upper leg section 21 and the lower leg section 22 may have a bend or bend. The

lower leg sections

221, 222 shown in figures 11, 13, 14 each have an S-shaped curved section.

Wherein the implant of fig. 10 has 6 inferior branch ends, while the implant of fig. 11 may have 6 or 12 inferior branch ends. Alternatively, two adjacent rods of the implant of fig. 8 are butted or crossed by two adjacent lower branch sections, so that the functional part forms a net structure, but 12 of the ends are kept as free ends, see fig. 13 and 14. Alternatively, however, each two adjacent rods of the implant of fig. 8 are fixed at one end by the convergence of the adjacent two lower leg segments, so that the implant may have 6 such ends.

Based on the above description, the preferred embodiment of the present invention, referring to fig. 1 and 2, the angle α between the extending direction of the upper branch section 21 and the central axis is larger than the angle β between the extending direction of the lower branch section and the central axis. Such a construction may have a relatively small height (i.e. length along the central axis) given the maximum circumference of the functional part, which may be very advantageous in most cases.

The width of the functional portion constituting rod of the present invention is preferably reduced from the central portion 1 to the outside as a whole.

For example, the width of the superior branch 21 is greater than the inferior branch 22 (or 221, 222) and the lateral branch 23.

In a further preferred embodiment, the width of the side branch 23 decreases overall from its starting end to its end. For example, the side branch section 23 is divided into two sections different in width from the bottom of the upwardly extending curved section. The tail end of the rear half section with narrower width can be provided with a round head similar to a sphere, so that the inner wall of the cavity can be prevented from being punctured.

The length of the upper branch section 21 is preferably much smaller than that of the lower branch section 22 (or 221, 222), and the length ratio thereof can be 0.2-0.05.

It is preferred in the present invention that the distal end of the side branch section 23 is located at or near the central portion 1 in the direction of the central axis.

Vena cava filter

In another aspect of the present invention, there is provided a vena cava filter having any one of the configurations of the endoluminal implant described above, wherein the functional portion has a plurality of bars uniformly distributed along a circumferential direction for blocking the passage of thrombus through the functional portion.

Referring to fig. 10-12, three vena cava filters are shown.

Fig. 13 and 14 show a preferred vena cava filter according to the present invention, wherein each rod of the functional portion has two oppositely extending

lower branches

221 and 222 respectively led out of the bending portion 211, and when in a compressed state, the adjacent rods are abutted or crossed by the adjacent lower branches, so that the functional portion forms a net structure, as shown in fig. 16, 17 and 19.

Optionally, in the non-compressed state, two adjacent lower branch sections between adjacent rods are abutted away from the ends thereof, and the two lower branch sections are parallelly gathered from the abutted points to the ends, see fig. 13 and 14.

The side branch section 23 of the preferred vena cava filter embodiment of the present invention is led out from the bending part 211, and is led out firstly to be a straight section which is basically parallel to the lower branch section, and then is transited to be an arc-shaped bending section with gradually increased curvature radius, the deflection angle of the tail end of the arc-shaped bending section relative to the starting end of the arc-shaped bending section is larger than 180 degrees, and the tail end of the arc-shaped bending section points to the direction of the central axis. The side branch section 23 is located between the two

lower branch sections

221, 222, and the straight section of the side branch section 23 and the lower branch section 22 are arranged in the pole width direction.

Under the same condition, compared with a comparative vena cava filter which is not provided with a bending part and has an arc-shaped bent section as the lower branch section directly leading out the side branch section 23, the preferred vena cava filter embodiment of the invention has more excellent structural mechanics, the stress is integrally reduced, and the stress distribution is more uniform, referring to fig. 18 and 19, the stress at the root (namely the starting end) of the side branch section 23 of the preferred vena cava filter embodiment of the invention shown in fig. 19 is obviously reduced, and no stress concentration area exists at the root, compared with the comparative example shown in fig. 18, the risk of the fracture of the side branch section 23 at the root can be obviously reduced, the lower stress is beneficial to the compression and recovery of the side branch section 23, the forward jump is avoided or the recovery resistance is reduced, and the operability and the safety are greatly improved.

Filters implantable in lumens

It is an object of the present invention to provide an implantable intraluminal filter that can be constructed using at least the implant structure, the stem constituting the functional portion, or the vena cava filter described above. For example, the filter implantable in the lumen of the tube may have the structure of the implant described above, or may be the vena cava filter described above. The endolumenal filter has an anchoring member and a filtering member, each of which can be a rod selected from the aforementioned rods constituting the functional part and satisfying: the anchoring member and the filter member are configured to elastically deform under a compressive load in the implanted state and to satisfy that, at the same radial dimension after compression, the anchoring member has a radial spring force greater than a radial spring force of the filter member.

In general, the present invention provides a filter implantable within a lumen, generally comprising:

the filter has an unconstrained state and an implanted state in which it is radially compressed,

The testing of the radial elastic force of the anchoring member and the filtering member is a routine technique in the art, and a person skilled in the art can design a corresponding clamp or carrier according to the configuration of the anchoring member and the filtering member, and obtain the radial elastic force by measuring with a force testing device, such as a tensile machine.

For example, referring to the implant structure of FIGS. 1-6, which may be implemented as a filter within an implantable lumen, wherein the superior branch 21 may be implemented as a coupling member, the inferior branch 22 may be implemented as a filtering member, the lateral branch 23 may be implemented as an anchoring member, and at least one of the superior branch 21, the inferior branch 22, and the lateral branch 23 form a group, and the groups are arranged around the central portion 1, such as the arrangement of FIG. 10. Alternatively, one upper leg 21, two lower legs 22 (i.e. 221 and 222) and one side leg 23 may be grouped, with groups of members arranged around the central portion 1, such as the arrangement of fig. 11. It will be appreciated that the implant structures of figures 7-9 may also be used as filters within implantable lumens, with multiple sets of members arranged around the central portion 1, as shown in figure 12.

In the above-described implant structure, it is generally possible to satisfy the elastic relationship between the anchoring member and the filtering member by selecting the specifications (such as thickness) or the shapes of the respective members: the anchoring member and the filter member are configured to elastically deform under a compressive load in both the implanted state and such that, at the same radial dimension after compression, the anchoring member has a radial spring force greater than a radial spring force of the filter member. Such selection of the size or shape of the member is within the skill of those in the art, for example, selecting a thicker, shorter rod member is generally less prone to deformation than a thinner, longer rod member, which may have a greater spring force for the same amount of deformation. For another example, different rod member shapes may be selected to create differences in the amount of deformation under compressive load to achieve different radial spring forces. As an example, a rod member may be selected that has a more curved configuration in the direction of load application (e.g., radial to the filter), and the plurality of curved configurations may be configured to elastically deform in the direction of load application, which may provide a greater elastic force due to a greater amount of accumulated deformation when the rod member is radially loaded by compression by the same radial length as compared to a straight rod without curved configurations.

In order to verify the difference in radial spring force of the members, measurements may be taken.

For example, for the implant structure of fig. 1-6, the radial elastic force of the lower branch segment 22 and the side branch segment 23 can be measured by fixing the upper branch segment 21 in position, so that the test wall with the pressure sensor always contacts the outer edge of the lower branch segment 22 or the side branch segment 23 along the radial direction of the filter (i.e. the direction perpendicular to the MM axis), so that the test wall advances along the radial direction by a predetermined distance to form a simulated implantation state, and the lower branch segment 22 or the side branch segment 23 is elastically deformed by compression and has a radial elastic force, which can be measured by the pressure sensor. Typically, the test wall is advanced a predetermined distance in the radial direction for the lower branch 22 and the side branch 23 to be different such that the lower branch 22 and the side branch 23 have substantially the same radial dimension when measuring the radial spring force.

Wherein the test wall should have a sufficiently large area to maintain interference with the lower leg 22 or the side leg 23 during the test.

Alternatively, the center portion 1 may be directly fixed without positioning and fixing the upper branch portion 21, so that the test wall having the pressure sensor always contacts the outer edge of the lower branch portion 22 or the side branch portion 23 in the radial direction of the filter (i.e., the direction perpendicular to the MM axis), and the radial elastic force of the lower branch portion 22 and the side branch portion 23 in the simulated implantation state may be measured in the above-described manner. During testing, the upper branch 21 may be deformed along with the lower branch 22 or the side branch 23.

Similarly, the implant structure of fig. 7-9, which also acts as a filter structure, differs from the filter structure of fig. 1-6 described above in that it does not have a coupling member, wherein the upper and

lower support sections

21 and 22 together act as an integral rod-like filter member, and the additional rods 4 (i.e., the first array of rods described above) act as anchoring members, both of which extend directly from the central portion 1, are not directly connected to each other, but are relatively independent. The radial elastic force of the lower branch section 22 and the rod 4 can be measured by positioning and fixing the central portion 1, so that the test wall with the pressure sensor always contacts the outer edge of the lower branch section 22 or the rod 4 along the radial direction of the filter (i.e. the vertical direction of the MM axis), and the test wall advances along the radial direction by a preset distance to form a simulated implantation state, and the lower branch section 22 or the rod 4 is elastically deformed by compression and has a radial elastic force, which can be measured by the pressure sensor.

In the filter construction described above, the filter elements and anchoring elements are arranged in layers, but may also be non-layered. By layered arrangement, it is meant that the plurality of filter elements are arranged such that the central elements of one layer are disposed axially of the filter, and the plurality of anchoring elements are arranged such that the central elements of another layer are disposed at different positions axially of the filter.

Preferred filter constructions have the anchoring member closer to the central element in the axial direction of the filter, see fig. 1-9. The central member can transmit the manipulation force to the anchoring member more effectively, and thus the precision of the manipulation can be improved.

The layered arrangement of filter elements and anchoring elements constitutes a filter part and an anchoring part, respectively, which in turn may have different diameters. Referring to fig. 10-12, the outer rim of the plurality of filter elements forms a third outer perimeter 33 of the filter, which is the diameter of the filter portion, and the outer rim of the plurality of anchor elements forms a second outer perimeter 32 of the filter, which is the diameter of the anchor portion, and referring again to fig. 1-9, the third outer perimeter 33 and the second outer perimeter 32 are at different distances from the central portion 1 along the axial direction (MM axis) of the filter, i.e., the filter portion and the anchor portion are at different diameters.

The main difference between the two types of filter structures is the coupling members, which should have elastic deformability, so that a linkage is formed between the anchoring members and the filtering members in each group, all coupling members being collectively fixed at one end to the central part.

Referring to fig. 1-19, the central portion 1 is shown to correspond to the central component of the filter described above, in contrast to the coupling member formed by the upper leg 21, the central portion 1 being a hub and being substantially rigid, and referring to fig. 7-9, the upper leg 21 and the lower leg 22 together being a rod-like filter member, the elastic deformation occurring when compressed or stretched does not cause displacement or change in shape of the further rod 4, the deformation stress of the upper leg 21 or the lower leg 22 being transmitted to the central component but not substantially to the rod 4. Referring to fig. 1-6 and 13-19 again, the anchoring member formed by the side branch section 23 is elastically deformed by compression or stretching, the deformation stress is transmitted to the upper branch section 21, and the upper branch section 21 is correspondingly elastically deformed and drives the lower branch section (22, 221 or 222) to generate position change or shape change.

Preferably, said anchoring member or filter member is actuated at least in a radial direction of the filter, which is very advantageous for adjusting the shape, position or attitude of the anchoring member or filter member in the implanted state.

The anchoring member and the filter member form an actuating relationship therebetween further enhancing the ability to indirectly manipulate the filter member. This means that by manipulating the change in position or attitude of the anchoring member it is possible to achieve simultaneously an effective adjustment of the position and attitude of the filter member, while the change in position or attitude of the filter member is substantially not or to a lesser extent.

Taking the filter shown in fig. 13-15 as an example, the filter may be implanted within a lumen (e.g., the inferior vena cava). The illustrated filter has a double layer of support, with the anchoring member (i.e., side branch segment 23) providing a greater radial support force design, serving a primary anchoring function, positioning and retaining the filter within the implanted vena cava, while, at the same time, the filter has the following characteristics due to the filter member (i.e., lower branch segments 221, 222) providing less radial support force, as constrained by the first layer of rods in attitude, orientation, etc. within the implanted vena cava, as: as long as the anchoring part formed by the six anchoring components is ensured to be positioned at the center of the venous cavity, the second layer of rod which mainly plays a role in filtering can be also positioned at the center of the venous cavity, the phenomenon that thrombus cannot be intercepted due to the offset of the filtering components is effectively avoided, and the filtering effect is guaranteed.

The design has more beneficial effects in certain specific scenes, for example, when the filter is released in an included angle in a vein, the inclination of the filter in the vein is inevitable, when the filter is implanted into a inferior vena cava through a jugular vein, the filter member is released from the delivery sheath before the anchoring member, the filter member is attached to the inner wall of the blood vessel and plays an auxiliary anchoring function, the released anchoring member has larger radial elastic force and can overcome the directional effect of the anchoring of the filter member on the filter, so that the side of a recovery hook released behind the filter tends to the center of the vein cavity, the inclination angle of the filter is reduced, and the anchoring member has the performance of 'correcting deviation' and redirecting the filter.

The above effect is particularly dependent on the phase-actuated design of the anchoring member and the filter member, for example, the filter shown with both anchoring and filter members being jointly branched by the coupling member, which significantly improves the ability of the filter member to be restrained by the anchoring member.

The offset arrangement of the two members in the circumferential direction is also a means for improving the above effect, which reduces the tension between the anchor member and the filter member distributed on the opposite side, facilitates the release of the anchor member and the filter member, and improves the re-oriented filter effect.

In addition, the strainer has better maneuverability and reorientation capabilities in combination with the anchoring members of the load cushioning structure. For example, whether released via the femoral or jugular vein access, the angled placement of the strainer may result in incomplete release of some of the anchoring members, see fig. 20b, with a significant difference in the location of contact of at least one anchoring member with the inner wall of the vein as compared to the other anchoring members, which may be when the strainer is released, with the port end of the delivery sheath carrying the strainer being offset from the center of the vein, causing the aforementioned anchoring members to be too close to the inner wall of the vein for adequate release, and the strainer to be susceptible to tilting under varying loads. The U-shaped load buffering structure of the rod structure of the anchoring member gives it a telescopic elasticity of radial length, thus providing power and space for the deformation of the anchoring member or filtering member, possibly causing the anchoring member or filtering member to be completely released, in the axial direction of the lumen of the vein, by dragging or pulling the delivery cable (depending on the passage) connecting the filter, see fig. 20c, thus achieving the function of "rectifying", reorienting the filter as previously described.

The illustrated filter is of a non-anchor or sharp design and does not cause damage to the inner wall of the vein, and thus twisting, shaking, migration, etc. of the filter within the vein does not cause damage to the vein, which is advantageous for the "deskewing" and reorientation operations described above.

The load buffering structure may be generally of a curved configuration in the direction of the load, capable of elastic deformation, such as the side branch 23 configuration shown in figures 1-4, 6, 13 or 15 or the rod 4 configuration of figures 7 and 9.

In a preferred embodiment, the load cushion structure of the side branch 23 is generally U-shaped, as shown in FIGS. 13 and 15, described above.

With a more preferred design, still referring to fig. 13 and 15, the anchor member has a load cushion structure which allows the load cushion structure to take a greater compressive load and reduce the strain in the root of the coupling member.

Test results

For the filter of fig. 13, the radial spring force of the inferior branch segment (221 or 222) and the lateral branch segment 23 in the simulated inferior vena cava implant state was measured as described above with reference to the method for measuring the radial spring force of the inferior branch segment 22 and the lateral branch segment 23 for the implant structures of fig. 1-6. The results of testing two (1822, 2226) specification filters in compression to target diameters are given below.

1822 size filters have an anchor portion diameter of 18 mm and a filter portion diameter of 22 mm in the unconstrained state.

In the unconstrained state of the 2226 standard filter, the diameter of the anchor portion was 22 mm, and the diameter of the filter portion was 26 mm.

It should be understood that the implanted state of the filter described herein, in which the filter is radially compressed, may refer to a state in which the filter is compressed in a manner simulating insertion into a lumen of a real physiological anatomical structure, for example, a state in which a compressive load is applied to the filter by an expansion and compression device such as a tensile machine, a crimping machine, or the like.

While the invention has been described in detail and with reference to specific examples thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof as defined in the appended claims.

Claims

1. A lumen implantable filter, comprising:

2. A strainer according to claim 1 wherein: the plurality of anchoring members and filter members are arranged in layers in an axial direction of the strainer, wherein the plurality of anchoring members are arranged in one layer to form an anchoring portion having an outer edge diameter, and the plurality of filter members are arranged in another layer to form a filter portion having an outer edge diameter;

preferably, the anchoring portion is closer to the central member than the filter portion is to the axial direction.

3. A strainer according to claim 2 wherein: when the filter is in an unconstrained state, the outer diameter of the anchoring portion is smaller than the outer diameter of the filter portion.

4. A strainer according to claim 2 wherein: one end of the central component along the axial direction of the filter is provided with a connecting part for connecting with the conveying device; the other end of the central member is provided with a retrieval portion that can be captured by a retrieval device for intraluminal removal of the implanted filter.

5. The strainer of claim 4 wherein: the anchoring portion and the filter portion are located on the side of the connecting portion of the center member in the axial direction of the filter.

6. The strainer of claim 4 wherein: the central component is a hub, and the connecting part of the central component is threads arranged on the inner periphery of the hub and can be in threaded connection with the conveying device; the recovery part is a hook-shaped body formed by slotting the hub or a hook-shaped body attached to the hub, and can be captured by a recovery device with a collar.

7. A strainer according to claim 1 wherein: the anchoring member has a deformable load cushioning structure of curved configuration for cushioning compressive loads.

8. A filter as claimed in any one of claims 1 to 7, wherein: the anchoring members and the filtering members are arranged in corresponding groups, the anchoring members and the filtering members in each group are connected through a coupling member, and the anchoring members and the filtering members in each group can be mutually actuated through the coupling member;

preferably, the coupling members within each set are resiliently deformable by actuation by the anchoring member and/or the filtering member.

9. The strainer of claim 8 wherein: the elastic deformation of the anchoring members within each group actuates the filtering members and the coupling members;

10. A strainer according to claim 9 wherein: the anchoring member or the filter member is actuated at least in a radial direction of the filter.

11. The strainer of claim 8 wherein: the anchoring members and the filter members within a group are in a mutually displaced arrangement along the circumferential direction of the filter.

12. The strainer of claim 8 wherein: the anchoring member, the filtering member and the coupling member are rod-shaped members;

wherein the coupling members extend from the central member and extend away from the central member to ends thereof, the ends of each coupling member further extending to an anchoring member and two filter members extending outwardly of the coupling member, and the extended anchoring member is located between the two filter members.

13. A strainer according to claim 12 wherein: the coupling member is provided with a bending part close to the tail end of the coupling member, and an included angle between the tail end direction of the coupling member and the axial center line of the central part after the coupling member passes through the bending part is reduced;

the filter members extend axially of the filter below the bend, and two adjacent filter members from two adjacent coupling members extend toward each other and preferably make movable contact.

14. A filter as claimed in claim 12 or 13, wherein: the anchoring member is substantially coplanar with the coupling member from which it exits, and extends toward its tail section in a generally U-shaped or V-shaped curved configuration to form a load-cushioning structure.

15. A strainer according to claim 14 wherein: the tail section of the anchoring member is located axially above the bend and towards the central member.

16. A strainer according to claim 12 wherein: the stem width of the anchoring member and the filter member is less than the stem width of the coupling member, and the length of the anchoring member is less than the length of the filter member and greater than the length of the coupling member.

17. A filter as claimed in claim 1 or 12, wherein: the anchoring member and the filtering member are both non-invasive intraluminal wall structures.

18. A strainer according to claim 1 wherein: the filter is a thrombus filter implantable in the inferior vena cava.

19. A filter as claimed in any one of claims 1 to 18, wherein: the anchoring member and the filter member are configured to have different radial compression ratios, respectively, at the same radial dimension after compression;

wherein, at a radial dimension after compression of 18-32 mm, the anchoring member has a radial compression ratio of less than 30%, the filtering member has a radial compression ratio of more than 50%, and preferably when the anchoring member has a radial elasticity value of 2-8 times the radial elasticity value of the filtering member;

20. The strainer of claim 19 wherein: the anchoring member has a radial elasticity value of 0.2-0.8 newton, and the filtering member has a radial elasticity value of 0.05-0.2 newton.

21. A lumen implantable filter, comprising:

a central member removably connectable with a delivery device for transferring the filter within a lumen;

the plurality of anchoring members and the plurality of filter members are arranged in layers in an axial direction of the filter, wherein the plurality of anchoring members are arranged in one layer to form an anchoring portion having an outer diameter, and the plurality of filter members are arranged in another layer to form a filter portion having an outer diameter;

22. A strainer according to claim 21 wherein: the number of anchor members constituting the anchor portion is not more than the number of filter members constituting the filter portion;