WO2017113633A1

WO2017113633A1 - Filter

Info

Publication number: WO2017113633A1
Application number: PCT/CN2016/086117
Authority: WO
Inventors: 李安宁; 兰娟
Original assignee: 先健科技(深圳)有限公司
Priority date: 2015-12-29
Filing date: 2016-06-17
Publication date: 2017-07-06
Also published as: CN105662646A

Abstract

A filter (100) comprises a proximal-end filtration mesh (11), a distal-end filtration mesh (12), and a support segment (13); the proximal-end filtration mesh (11) is adjacent to the proximal end (101), and the distal-end filtration mesh (12) is adjacent to the distal end (102); the support segment (13) is connected between the proximal-end filtration mesh (11) and the distal-end filtration mesh (12); the conicity of the proximal-end filtration mesh (11) is smaller than the conicity of the distal-end filtration mesh (12). The radial supporting force of the proximal-end filtration mesh (11) is smaller than the radial supporting force of the distal-end filtration mesh (12); when a thrombus is intercepted by the proximal-end filtration mesh (11), the radial supporting force of the proximal-end filtration mesh (11) increases, reducing the likelihood of the filter (100) becoming crooked; thus the efficiency of the filter (100) in filtering thrombi is improved, and the risk of postoperative reoccurrence of embolism is mitigated.

Description

filter

[Technical Field]

The present invention relates to an implantable medical device, and more particularly to a filter.

【Background technique】

Pulmonary embolism (abbreviation: PE) refers to the clinical pathophysiological syndrome of pulmonary circulatory disorders caused by various embolism of the systemic occlusion, which has the characteristics of high incidence, acute onset and high mortality. According to statistics, the mortality rate of untreated pulmonary embolism is 20~30%, and the annual new cases account for about 0.2% of the population. According to China's 1.35 billion population, there are about 2.7 million new patients each year.

Various embolisms of the systemic circulation can cause pulmonary embolism. The most common embolus is a thrombus. There are many factors in the formation of blood clots, including: trauma or fracture, trauma, large surgery, extensive burns, pregnancy, childbirth, long illness, bed, long-distance ride or long-term sit-in, long sit-in and down Hey. These thrombi are generally slightly adhered to the wall of the tube and are prone to fall off. Free emboli can cause severe lesions such as pulmonary embolism. Filters have been clinically proven to be a safe and effective means of preventing pulmonary embolism, reducing the incidence of pulmonary embolism. The filter is implanted into the inferior vena cava to prevent thrombosis of the lower extremity from reaching the lungs along the bloodstream, thereby preventing pulmonary embolism.

When the existing filter to be occluded is intercepted by the near-end filter, it is prone to skew. The reduced efficiency of the slanted filter to filter the embolus increases the risk of re-embedding of the patient after surgery.

[Summary of the Invention]

It is an object of the present invention to provide a filter in view of the above deficiencies of the prior art. The taper of the near-end filter of the filter near the proximal end of the filter is smaller than the taper of the telecentric filter near the telecentric end of the filter, and the radial support force of the near-end filter is smaller than the radial support of the telecentric filter. . When the emboli is intercepted by the near-end filter, the radial support force of the near-end filter increases, which reduces the radial support force of the near-end filter and the radial support of the telecentric filter. The gap between the two reduces the possibility of filter skew, improves the efficiency of the filter plug, and reduces the risk of re-embedding after surgery.

The present invention provides a filter comprising a body portion having opposing proximal and distal ends. The body portion includes a proximal end filter and a telecentric filter positioned between the proximal end and the distal end. In the state in which the filter is naturally released, the near-end filter and the telecentric filter are spatially tapered structures composed of a plurality of mesh wires. The taper of the proximal end filter is smaller than the taper of the telecentric filter.

In one embodiment, the proximal end filter comprises a plurality of connected first Y-shaped units. Each of the first Y-shaped units includes a first network line and two second network lines formed by a fork extending from one end of the first network line. The plurality of first mesh lines of the plurality of first Y-shaped cells converge at the proximal end. An end of each of the first Y-shaped cells that is away from the proximal end is connected to the telecentric filter.

In one embodiment, the distance between the connection point of the first wire and the second wire in the first Y-shaped unit to the longitudinal central axis of the filter in a state in which the filter is naturally released The ratio of the size of the filter to the largest outer diameter in the direction perpendicular to the longitudinal central axis of the filter ranges from 1:10 to 7:16.

In one embodiment, two adjacent first network lines of two adjacent first Y-type cells and two adjacent second second network lines of two corresponding first Y-type units are enclosed A first diamond shaped filter unit is formed. a projected area of a plurality of first rhombic filter units of the filter in a cross section perpendicular to a longitudinal central axis of the filter and a longitudinal direction of the filter perpendicular to the filter in a state in which the filter is naturally released The ratio of the area of the circle corresponding to the largest outer diameter in the direction of the central axis ranges from 1:10 to 9:10.

In one embodiment, the telecentric filter comprises a plurality of connected second Y-shaped cells. Each of the second Y-shaped units includes a third network cable and two fourth network cables formed by a bifurcation extension of one end of the third network cable. A plurality of third network lines of the plurality of the second Y-type cells converge at the telecentric end. The end of the fourth network line of each second Y-shaped unit remote from the telecentric end is connected to the near-end filter.

In one embodiment, the distance between the connection point of the third wire and the fourth wire in any of the second Y-shaped cells to the longitudinal central axis of the filter in a state in which the filter is naturally released The ratio of the size of the filter at the maximum outer diameter in the direction perpendicular to the longitudinal central axis of the filter after the filter is naturally released is in the range of 1:10 to 7:16.

In one embodiment, the telecentric filter comprises a plurality of linear fifth wires. The ends of the plurality of fifth mesh lines near the telecentric end converge at the telecentric end. An end of each of the fifth network wires remote from the telecentric end is connected to the support segment.

In one embodiment, the body portion further includes a support section coupled between the proximal end filter and the telecentric filter. The support section includes a plurality of straight rods. The straight rod is generally parallel to the longitudinal central axis of the filter.

In one of the embodiments, the number of the straight rods is plural, and the lengths of the plurality of straight rods are the same.

In one embodiment, the width of the straight rod in the circumferential direction of the filter is greater than the circumferential direction of the filter in any of the proximal end filter and the distal end filter. width.

In one of the embodiments, the support section further includes at least one curved rod. One end of the curved rod is connected to the near-end filter and the other end is connected to the telecentric filter.

In one embodiment, the straight rod and the curved rod are spaced apart in a circumferential direction of the filter.

In one embodiment, the straight rod and the curved rod are not spaced apart from each other in the circumferential direction of the filter.

In one of the embodiments, at least one of the straight rods is provided with at least one fixing anchor for fixing the filter. One end of the fixing anchor is fixed to the straight rod, and the other end of the fixing anchor is a free end and extends toward the proximal end.

In one of the embodiments, the angle between the anchor and the straight rod directly connected thereto is less than 90 degrees.

In one of the embodiments, the vertical distance of the free end of the anchor to the straight rod directly connected to the fixed anchor is less than or equal to 3 mm.

In one of the embodiments, the filter further comprises a recovery hook. The recovery hook is disposed at a telecentric end or a proximal end of the main body portion. The recovery hook is a tubular structure having an opening. The opening direction of the recovery hook extends outward in the radial direction of the filter and is offset toward the main body portion. The opening of the recovery hook has a width in a direction perpendicular to the opening that is greater than or equal to 1/5 of an outer diameter of the tubular structure of the recovery hook. The opening of the recovery hook has a depth in a direction perpendicular to a longitudinal central axis of the filter that is less than or equal to 19/20 of an outer diameter dimension of the tubular structure of the recovery hook.

In one embodiment, the material of the filter is a nickel titanium alloy. The filter is formed by cutting a mesh line of the near-end end filter and the telecentric end filter on a nickel-titanium tube.

Compared with the prior art, the invention has the following beneficial effects:

The taper of the near-end filter near the proximal end of the filter of the invention is smaller than the taper of the telecentric filter near the telecentric end of the filter, and the radial support force of the near-end filter is smaller than the radial support of the telecentric filter. When the emboli is intercepted by the near-end filter, the radial support force of the near-end filter increases, which reduces the radial support force of the near-end filter and the radial support force of the telecentric filter. The gap between the two reduces the possibility of filter skew, improves the efficiency of the filter plug, and reduces the risk of re-embedding after surgery.

[Description of the Drawings]

1a-1b are schematic diagrams showing the overall structure of a filter according to a first embodiment of the present invention, the main body of the filter comprising a proximal end filter, a telecentric filter, and a proximal end filter and a telecentric end. a support section of the filter, the near-end filter comprises a plurality of first diamond-shaped filter units; wherein, Figure 1a is a perspective view, Figure 1b is a front view;

Figure 1c is a cross-sectional view of the filter of Figure 1a in cross section with a longitudinal central axis of the filter;

Figure 1d is a partial front elevational view of the main body of the filter of Figure 1a;

Figure 1e is a projection view of the proximal end filter of the filter of Figure 1a in a cross section perpendicular to the longitudinal central axis of the filter;

Figure 1f is a projected area of a plurality of first rhombic filter units of the filter of Figure 1a in a cross section perpendicular to a longitudinal central axis of the filter and the filter is oriented perpendicular to a longitudinal central axis of the filter Schematic diagram of the ratio of the area of the circle corresponding to the outer diameter;

Figure 1g is a projection view of the telecentric end filter of the filter of Figure 1a in a cross section perpendicular to the longitudinal central axis of the filter;

Figure 2 is a schematic view showing the structure of the recovery hook of the filter of Figure 1a;

Figure 3 is a schematic view showing the structure of the anchor of the filter of Figure 1a;

Figure 4 is a schematic view of the filter of Figure 1a rotated about a fixed anchor;

5a-5b are schematic diagrams showing the overall structure of a filter according to a second embodiment of the present invention. The main body of the filter includes a proximal end filter, a telecentric filter, and a proximal end filter and a telecentric end. a support section of the filter; wherein, Figure 5a is a perspective view, and Figure 5b is a front view;

Figure 5c is a partial front elevational view of the main body of the filter of Figure 5a;

Figure 5d is a projection view of the telecentric end filter of the filter of Figure 5a in a cross section perpendicular to the longitudinal central axis of the filter;

Figure 6 is a developed image of the inferior vena cava taken after 14 days of implantation of the filter of Comparative Example 1 into the inferior vena cava.

【detailed description】

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. The terminology used herein is for the purpose of describing particular embodiments, and is not intended to limit the invention.

For clarity of description, the end of the filter near the heart, the blood outflow filter is referred to as the proximal end, and the end of the filter away from the heart and blood into the filter is referred to as the telecentric end.

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

Embodiment 1

In the embodiment, the main body portion of the filter is cut and shaped by a nickel-titanium tube having an outer diameter of 0.2-4 mm. It can be understood that the filter can also be woven and shaped by a nickel-titanium wire having an outer diameter of 0.05-0.8 mm or a nickel-titanium flat belt having a width of 0.05-0.5 mm and a length of 0.15-1 mm. The filter has superelastic and self-expanding properties.

Referring to FIGS. 1 a and 1 b , the filter 100 of the first embodiment includes a main body portion 10 and a recovery hook 20 and a fixed anchor 30 disposed at one end of the main body portion 10 .

The body portion 10 has opposite proximal ends 101 and distal ends 102, including a proximal end filter 11 near the proximal end 101, a telecentric filter 12 near the telecentric end 102, and a proximal end filter. A support section 13 between the mesh 11 and the telecentric filter 12. After the filter 100 is naturally released in the blood vessel, the support section 13 is used to support the vessel wall, and the proximal end filter 11 and the telecentric filter 12 are used to filter the thrombus. The proximal end filter 11 is gathered by a plurality of mesh wires at the proximal end 101 to form a spatially tapered structure. The telecentric filter 12 is converged by a plurality of mesh wires at the telecentric end 102 to form a spatially tapered structure.

Each wire can be straight, curved, or partially straight, with the rest being curved.

It can be understood that the network cable of the near-end filter 11 and the network cable of the telecentric filter 12 can also be an irregular curve or a combination of a curve and a straight line.

Referring to FIG. 1c, the taper of the proximal end filter 11 is such that the outer diameter dimension of the telecentric end of the proximal end filter 11 and the proximal end filter 11 have the longitudinal central axis of the filter 100 when the filter 100 is in the natural release state. The ratio of the projection on the cross section along the longitudinal length of the longitudinal center axis of the filter 100; the taper of the telecentric end filter 12 is the outer diameter of the proximal end of the telecentric filter 12 when the filter 100 is naturally released. The ratio of the projection of the telecentric filter 12 on the section having the longitudinal central axis of the filter 100 along the longitudinal length L2 of the longitudinal center axis of the filter 100, and the taper of the proximal end filter 11 is smaller than that of the telecentric filter 12 Taper. Preferably, in the present embodiment, the outer diameter dimension of the telecentric end of the proximal end filter 11 is equal to the outer diameter of the proximal end of the telecentric filter 12, and is equal to the longitudinal center axis of the filter 100 perpendicular to the filter 100. The dimension H at the largest outer diameter in the direction.

When the filter 100 is naturally released, the projection of the proximal end filter 11 on the section having the longitudinal central axis of the filter 100 along the longitudinal center axis of the filter 100 has a maximum length L1 greater than that of the telecentric end filter 12 in the longitudinal direction of the filter 100. The projection on the section of the central axis is along the maximum length L2 of the longitudinal central axis of the filter 100.

The proximal end filter 11 near the proximal end 101 has a long length, and can buffer the blood flow from the distal end 102 to the main body 10 at a high speed, so that the thrombus enters the proximal end filter 11 in an orderly manner. The eddy current is not formed to cause a large impact force on the near-end filter 11 to cause the filter 100 to be displaced. At the same time, the longer proximal cardiac filter 11 can ensure that the blood flow of the two renal veins to the thrombus of the proximal cardiac filter 11 produces a large enough area and a long enough scouring and cutting action to ensure the long-term vena cava. unobstructed.

Referring to FIGS. 1d and 1e, the proximal end filter 11 includes a plurality of connected first Y-shaped units 110, each of the first Y-shaped units 110 including a first wire 111 and a fork extending from one end of the first wire. Two second network lines 112. The plurality of first mesh wires 111 of the plurality of first Y-shaped cells 110 converge at the proximal end 101, whereby the proximal-end filter 11 has a spatially tapered structure when the filter 100 is naturally released. The end of the second wire of each first Y-shaped unit 110 away from the proximal end 101 is connected to the support section 13.

The distance from the projection point of the second network line 112 of each first Y-shaped unit 110 to the first network line 111 on the longitudinal central axis of the filter 100 to the proximal end 101 and the corresponding second network line 112 and support section 13 The ratio of the intersection of the intersection point on the longitudinal central axis of the filter 100 to the distance from the proximal end 101 ranges from 1:10 to 9:10. Specifically, in the present embodiment, the ratio is 1:2.

Each of the first wire 111 and the second wire 112 may be linear or curved, and may be partially curved, and the remaining portions are linear. In the present embodiment, the proximal end filter 11 includes six linear first linear wires 111 of equal length and twelve linear second mesh wires 112 of equal length. The angle formed by each adjacent two first mesh wires 111 at the proximal end 101 is equal.

Referring to FIG. 1c, when the filter 100 is naturally released, the distance h1 between the connection point A of the first wire 111 and the second wire 112 in the first Y-shaped unit 110 to the longitudinal central axis of the filter 100 is perpendicular to the filter 100. The ratio of the dimension H at the outer diameter in the longitudinal central axis direction of the filter 100 is in the range of 1:10 to 7:16. Specifically, in the present embodiment, the ratio is 1:4.

Referring to FIG. 1e and FIG. 1f, the two first network lines 111 of each adjacent two first Y-type units 110 and the adjacent two second network lines 112 of the corresponding two first Y-type units 110 are enclosed. A first diamond filter unit 113 is formed. In a state where the filter is naturally released, the projected area S1 of the plurality of first rhombic filter units 113 of the near-end filter 11 in a cross section perpendicular to the longitudinal central axis of the filter 100 and the longitudinal central axis direction of the filter 100 The ratio of the area S0 of the circle corresponding to the largest outer diameter is in the range of 1:10 to 9:10. Specifically, in the present embodiment, the ratio is 5.5:10.

Since the size of the first rhomboid filter unit 113 is moderate, the thrombus which causes pulmonary embolism can be sufficiently filtered, and the vascular obstruction caused by the interception of the large and small blood vessels is not ensured, and the long-term patency of the vein is ensured.

Referring to both FIG. 1d and FIG. 1g, the telecentric filter 12 includes a plurality of connected second Y-shaped units 120. Each of the second Y-shaped units 120 includes a third network line 121 and two fourth network lines 122 formed by a bifurcation extension of one end of the third network line. A plurality of third mesh lines 121 of the plurality of second Y-shaped cells 120 converge at the telecentric end 102. Thus, the telecentric end filter 12 has a spatially tapered configuration when the filter 100 is naturally released. The end of the fourth wire 122 of each second Y-shaped unit 120 remote from the telecentric end 102 is connected to the support segment 13.

Each of the third mesh wires 121 and the fourth mesh wires 122 may be linear or curved, and may be partially curved, and the remaining portions are linear. In the present embodiment, the telecentric end filter 12 includes six linear third network wires 121 of equal length and six linear fourth mesh wires 122 of equal length. The angle formed by each adjacent two third mesh wires 121 at the telecentric end 102 is equal.

Referring to FIG. 1c, when the filter 100 is naturally released, the distance h2 between the connection point B of the third network line 121 and the fourth network line 122 in each second Y-shaped unit 120 to the longitudinal central axis of the filter 100 is with the filter 100. The ratio of the dimension H at the outermost diameter perpendicular to the longitudinal central axis direction of the filter 100 ranges from 1:10 to 7:16. Specifically, in the present embodiment, the ratio is 1:8.

As can be seen from the above, the main body portion 10 of the filter 100 has an asymmetrical structure as a whole, and the number of the first Y-shaped units 110 in the near-heart end filter 11 is the number of the second Y-shaped units 120 in the telecentric end filter 12. Twice, that is, the density of the network structure of the near-end filter 11 is greater than the density of the network structure of the telecentric filter 12.

Referring again to Figures 1a and 1b, the support section 13 includes six straight rods 131 of equal length. Each of the straight rods 131 is substantially parallel to the longitudinal central axis of the filter 100 and evenly spaced along the circumferential direction of the filter 100.

It can be understood that the straight rod 131 can be directly connected to the proximal end filter 11 and the telecentric filter 12, and the straight rod 131 can also pass through the curved section between the proximal end filter 11 and the telecentric end filter 12. Connected.

The width of each straight rod 131 in the circumferential direction of the filter 100 is greater than the width of any of the mesh lines of the proximal end filter 11 and the telecentric end filter 12 in the circumferential direction of the filter 100.

In the present embodiment, the width of each of the straight rods 131 in the circumferential direction of the filter 100 is 0.8 mm, and the width of the wire along the circumferential direction of the filter 100 is 0.4 mm.

It can be understood that in other embodiments, one or more straight rods of the plurality of straight rods 131 may be replaced by the curved rods, as long as the taper of the near-end filter of the filter is smaller than the taper of the telecentric filter. . It can also be understood that, in other embodiments, at least one of the plurality of straight rods 131 may be connected to the near-end filter or the telecentric filter through at least one curved rod, as long as the filter is close to the center The taper of the end filter is smaller than the taper of the telecentric filter. It can also be understood that in other embodiments, a plurality of straight rods 131 may also have a straight rod omitted. In this case, a network cable of the near-end filter is directly connected to a network cable of the telecentric filter. Connected as long as the taper of the near-end filter of the filter is less than the taper of the telecentric filter.

It can be understood that in other embodiments, the plurality of straight rods 131 and the curved rods may be spaced apart from each other in the circumferential direction of the filter. It can also be understood that in other embodiments, the straight rod 131 and the curved rod can also be distributed in the circumferential direction of the filter without spacing. For example, all the straight rods 131 can be sequentially distributed in the circumferential direction of the filter, and all the curved rods can follow the straight line. The rods 131 continue to be sequentially distributed in the circumferential direction of the filter, that is, the curved rods can be randomly arranged between the plurality of straight rods 131.

It should also be understood that the structure of the curved rod may include one or more curved wavy lines. Referring to FIG. 2, in the present embodiment, the recovery hook 20 is disposed at the telecentric end 102 of the main body portion 10. The connection of the recovery hook 20 to the grasper (not shown) can remove the filter 100 implanted into the blood vessel from the blood vessel. Recovered in vitro. The recovery hook 20 is a tubular structure having an opening. The opening direction of the recovery hook 20 extends outward in the radial direction of the filter 100 and is offset toward the main body portion 10, that is, the angle β between the opening direction of the recovery hook 20 and the longitudinal central axis of the filter 100 is less than 90 degrees. The width D of the opening of the recovery hook 20 in the direction perpendicular to the opening is greater than or equal to 1/5 of the outer diameter dimension d of the tubular structure of the recovery hook 20, so that the recovery device can easily catch the recovery hook 20. The depth S of the opening of the recovery hook 20 in the direction perpendicular to the longitudinal central axis of the filter 100 is less than or equal to 19/20 of the outer diameter dimension d of the tubular structure of the recovery hook 20, so that when the recovery device catches the recovery hook 20, the recovery device The recovery hook 20 can be pulled into the recovery sheath. In the present embodiment, the width D of the opening of the recovery hook 20 in the direction perpendicular to the opening is 1 mm, and the depth S of the opening of the recovery hook 20 in the direction perpendicular to the longitudinal central axis of the filter 100 is 1.5 mm.

When the filter 100 of the present embodiment is subjected to high-speed flushing of blood flow in a blood vessel, the filter 100 may be inclined. However, since the taper of the telecentric filter 12 near the telecentric end 102 is greater than the taper of the proximal end filter 11 near the proximal end 101, the proximal end 101 of the filter 100 will first contact the vessel wall when the filter 100 is skewed, thereby avoiding The recovery hook 20 at the telecentric end 102 is unable to catch the risk of recovery due to contact with the vessel wall. Further, when the filter 100 of the present embodiment is implanted in a human body, the filter 100 in a radially contracted state is released from the sheath tube, and the radial support force of the proximal-end filter 11 which is released first is slightly small, so the release speed is slow. When the release position is found to be poor, the partially released proximal end filter 11 can be withdrawn from the sheath, the position of the sheath can be adjusted and released again, and the slowly released proximal end filter 11 will also adhere to the vessel wall, ensuring that The stability of the filter 100 after implantation.

Referring to FIG. 3, in the present embodiment, the filter 100 further includes a fixing anchor 30. The anchor 30 is disposed on at least one of the straight rods 131 of the support section 13 and has an angle α of less than 90 degrees with the straight rod 131 directly connected thereto. The anchor 30 has an elongated shape, one end of which is fixed to the straight rod 131, and the other end is a free end and extends toward the proximal end 101. The vertical distance of the free end of the anchor 30 to the straight rod 131 directly connected to the fixed anchor 30 is less than or equal to 3 mm. Thus, when the filter 100 is naturally released within the blood vessel, the straight rod 131 of the support section 13 supports the vessel wall, and the anchor anchor 30 penetrates the vessel wall, further providing a reliable fixation for the filter 100, preventing the filter 100 from moving in the blood vessel. Bit. It can be understood that two or more fixing anchors 30 can be disposed on one straight rod 131 according to actual needs. It can be understood that when the support section 13 has a curved rod inside, the fixed anchor 30 can also be disposed on the curved rod according to actual needs.

Referring to FIG. 4, when the filter 100 of the present embodiment is subjected to high-speed flushing of blood flow in a blood vessel, the filter 100 may be inclined. However, since the taper of the telecentric end filter 12 near the telecentric end 102 is greater than the taper of the proximal end filter 11 near the proximal end 101, the radial support force of the telecentric end filter 12 is large, which facilitates fixing the anchor 30 away from the far side. The free end of the heart end 102 penetrates the vessel wall. When the filter 100 is flushed by the blood flow, the filter 100 will only rotate at a small angle around the fixed anchor 30 without displacement, ensuring stability of the filter 100 after implantation.

The filter 100 is implanted into the inferior vena cava by percutaneous puncture of the femoral vein, and the X-ray developing device detects that the filter 100 is not tilted, displaced or inverted after being implanted into the inferior vena cava. The filter 100 was taken out after 14 days of implantation, and the patient did not have symptoms such as abdominal pain, that is, the filter 100 was not damaged when the filter 100 was taken out.

Embodiment 2

Referring to FIG. 5a, the structure of the filter 200 of the present embodiment is substantially the same as that of the filter 100 of the first embodiment. The filter 200 includes a main body portion 40 and a recovery hook 50 provided at one end of the main body portion 40 and a fixing anchor 60. The body portion 40 has opposite proximal ends 401 and distal ends 402, including a proximal end filter 41 near the proximal end 401, a telecentric filter 42 near the telecentric end 402, and a proximal end filter. A support section 43 between the mesh 41 and the telecentric filter 42. The filter 200 differs from the filter 100 in that the structure of the telecentric filter 42 is different from the structure of the telecentric filter 12.

Referring to FIG. 5b, FIG. 5c and FIG. 5d, the telecentric filter 42 of the present embodiment is different from the telecentric filter 42 of the first embodiment in that the telecentric filter 42 comprises six linear types. The fifth network cable 421, the ends of the six fifth network cables 421 near the telecentric end 402 converge at the telecentric end 402. Thus, the telecentric end filter 42 has a spatially tapered configuration when the filter 200 is naturally released. The angle formed by each of the fifth mesh wires 421 at the telecentric end 402 is equal. The end of each of the fifth wire 421 remote from the telecentric end 402 is connected to the proximal end filter 41.

Each of the fifth network wires 421 may be linear or curved, and may be partially curved, and the remaining portions are linear.

The filter 200 is implanted into the inferior vena cava by percutaneous puncture of the femoral vein, and the X-ray developing device detects that the filter 200 has not been tilted, displaced or inverted after being implanted into the inferior vena cava. The filter 200 was taken out after 14 days of implantation, and the patient did not have symptoms such as abdominal pain, that is, the filter 200 was not damaged when the container 200 was taken out.

It can be understood that when the filter of the present invention is cut and shaped by a nickel-titanium tube having an outer diameter d, the plurality of strips of the near-end filter and the telecentric filter can be cut on the same nickel-titanium tube. Straight rod for the wire and support section. The width of each straight rod along the circumferential direction of the filter is less than 1/2 of the outer diameter dimension d of the nickel-titanium tube, and the width of the straight rod along the circumferential direction of the filter is greater than the composition of the near-end filter and the telecentric filter. The width of the curved segment and/or the straight segment of the wire along the circumferential direction of the filter.

When the filter is cut and shaped by a nickel-titanium tube having an outer diameter d, the recovery hook can be integrally formed with the main body of the filter, that is, the recovery hook can be directly cut at the end of the nickel-titanium tube. When the filter is woven and shaped by using a nickel-titanium wire or a nickel-titanium flat belt, the recovery hook may also be a nickel-titanium tube having an opening and an outer diameter d, which may be adjacent to the proximal end of the main body of the filter or The telecentric end is connected by welding.

It should also be understood that the recovery hook may also be disposed at the proximal end of the main body portion according to actual needs, as long as the delivery device of the delivery filter can place the filter at a predetermined position of the blood vessel, and the recovery device of the recovery filter can be connected with the recovery hook, and Recover the filter and withdraw it from the blood vessel.

It will be understood that the filter of the present invention may also be made of other superelastic materials (for example, stainless steel wire, cobalt-chromium-nickel-molybdenum-iron alloy, cobalt-chromium alloy or polymer), or may be self-expanding. Any other suitable material is formed.

In summary, after the filter of the present invention is implanted into a blood vessel of a human body and naturally released in a blood vessel, the taper of the near-end filter near the proximal end of the filter is smaller than the taper of the telecentric filter near the distal end of the filter, near The radial support force of the cardiac filter is less than the radial support force of the telecentric filter. Compared with the prior art, the filter of the present invention has the following advantages: 1) when the emboli is intercepted by the near-end filter, the radial support force of the near-end filter increases, and the near-end filter is reduced. The difference between the radial supporting force and the radial supporting force of the telecentric filter reduces the possibility of filter skew, improves the efficiency of the filter plug, and reduces the risk of re-embedding of the patient after surgery; When the filter whose recovery hook is set at the telecentric end is implanted into the human body, the filter in the radial contraction state is released from the sheath tube, and the radial support force of the proximal-end filter that is released first is slightly smaller, so the release speed is Slowly, when the release position is found to be poor, the partially released proximal end filter can be retracted from the sheath, the position of the sheath can be adjusted and released again, and the slowly released proximal end filter will also adhere to the vessel wall, ensuring the filter. Stability after implantation; 3) The radial support force of the telecentric filter is slightly larger, and the filter will be quickly ejected from the sheath when it is released. The anchor will receive a greater rebound force, and the free end of the anchor will penetrate. The strength of the blood vessels is greater, ensuring the filter planting Post-stability; 4) The length of the proximal-end filter is greater than the length of the telecentric filter, which allows multiple thrombi to enter the proximal-end filter in an orderly manner, avoiding multiple thrombus at the entrance of the near-end filter. The occurrence of eddy currents avoids the occurrence of eddy current impact on the filter body, reducing the possibility of filter skew; 5) The near-end filter includes a plurality of diamond-shaped filter units of moderate size, and the sizes are moderate. The rhomboid filter unit can not only fully filter the thrombus, but also avoid the occurrence of vascular obstruction due to the interception of large and small blood clots, ensuring long-term patency of the vein.

Comparative example one

The structure of the filter of the first embodiment is substantially the same as the structure of the filter 100 of the first embodiment, and includes a near-end filter near the proximal end, a telecentric filter near the telecentric end, and a filter connected to the proximal end and the far end. The support section between the heart end filters. The difference is that when the filter of Comparative One is naturally released in the blood vessel, the taper of the near-end filter is greater than the taper of the telecentric filter.

The filter of Comparative Example 1 was implanted into the inferior vena cava by percutaneous puncture of the femoral vein using a delivery sheath. Since the taper of the near-end filter is larger than the taper of the telecentric filter, the radial support force of the near-end filter is greater than the radial support of the telecentric filter. After implantation, the near-end filter intercepts the emboli in the blood, and the gap gradually increases, eventually causing the filter to be skewed, affecting the filtration efficiency of the filter; and, due to the skew of the filter, the partial anchor is caused. The position where the free end is in contact with the blood vessel wall is unstable. During the breathing, due to the change of the abdominal cavity pressure, the anchor anchor penetrates and pulls out the blood vessel wall several times, causing the blood vessel at the position to be punctured, and the patient has symptoms such as abdominal pain. After the detection by the developing device, the patient developed abdominal hematoma, and the filter was taken out in advance, and the expected therapeutic effect was not achieved.

Referring to FIG. 6, the blood is exuded to form a hematoma after the blood vessel wall of the inferior vena cava is punctured at the implantation position before the filter of the inferior vena cava is removed by the developing device. From this, it can be seen that the filter of the present comparative example caused damage to the blood vessel after implantation.

The embodiments of the present invention have been described above with reference to the drawings, but the present invention is not limited to the specific embodiments described above, and the specific embodiments described above are merely illustrative and not restrictive, and those skilled in the art In the light of the present invention, many forms may be made without departing from the spirit and scope of the invention as claimed.

Claims

A filter comprising a body portion having opposite proximal and distal ends, the body portion including a proximal end filter and a telecentric end between the proximal end and the distal end a filter, in a state in which the filter is naturally released, the near-end filter and the telecentric filter are spatial conical structures composed of a plurality of mesh lines, wherein the near-end filter is The taper is smaller than the taper of the telecentric filter.
The filter according to claim 1, wherein said near-end filter comprises a plurality of connected first Y-shaped units, each of said first Y-shaped units comprising a first network line and said first network line Two second mesh lines extending at one end and extending, the plurality of first mesh lines of the plurality of first Y-shaped cells converge at the proximal end, the said each of the first Y-shaped units The end of the second wire away from the proximal end is connected to the telecentric filter.
The filter according to claim 2, wherein a connection point of said first wire and said second wire in said first Y-shaped unit to said filter is in a state in which said filter is naturally released The ratio of the distance of the longitudinal central axis to the largest outer diameter of the filter in the direction perpendicular to the longitudinal central axis of the filter ranges from 1:10 to 7:16.
The filter according to claim 2, wherein two adjacent ones of the first Y-shaped cells and two adjacent ones of the first Y-shaped cells The second wire is enclosed to form a first diamond-shaped filter unit, and in the state where the filter is naturally released, a plurality of the first diamond-shaped filter units of the filter are perpendicular to a longitudinal central axis of the filter The ratio of the projected area on the cross section to the area of the circle corresponding to the maximum outer diameter of the filter in the direction perpendicular to the longitudinal central axis of the filter ranges from 1:10 to 9:10.
The filter according to claim 1, wherein said telecentric filter comprises a plurality of connected second Y-shaped units, each of said second Y-shaped units comprising a third network cable and said third network cable Two fourth network lines formed by extending at one end, a plurality of third network lines of the plurality of second Y-shaped units converge at the telecentric end, and the fourth network line of each second Y-shaped unit An end remote from the telecentric end is connected to the proximal end filter.
The filter according to claim 5, wherein in the state in which the filter is naturally released, a connection point of the third network line and the fourth network line in any of the second Y-shaped units to the filter The ratio of the distance of the longitudinal central axis to the dimension of the outer diameter of the filter in the direction perpendicular to the longitudinal central axis of the filter after the filter is naturally released is in the range of 1:10 to 7:16.
The filter according to claim 1, wherein the telecentric end filter comprises a plurality of linear fifth network wires, and the plurality of fifth mesh wires are adjacent to the distal end of the telecentric end at the telecentric Converging at the end, each end of the fifth network line remote from the telecentric end is connected to the near-end filter.
The filter according to claim 1, wherein said main body portion further comprises a support section connected between said proximal end filter and said telecentric end filter, said support section comprising a plurality of straight rods. The straight rod is generally parallel to the longitudinal central axis of the filter.
The filter according to claim 8, wherein the number of the straight rods is plural, and the lengths of the plurality of straight rods are the same.
The filter according to claim 8, wherein a width of the straight rod in a circumferential direction of the filter is larger than any of the network lines of the near-end filter and the telecentric filter. The width of the filter in the circumferential direction.
The filter according to claim 8, wherein said support section further comprises at least one curved rod, one end of said curved rod being connected to said proximal end filter, and the other end being said to said telecentric The end filters are connected.
The filter according to claim 11, wherein the straight rod and the curved rod are spaced apart in a circumferential direction of the filter.
The filter according to claim 11, wherein the straight rod and the curved rod are not spaced apart from each other in a circumferential direction of the filter.
The filter according to claim 8, wherein at least one of said straight rods is provided with at least one fixing anchor for fixing said filter, and one end of said fixing anchor is fixed to said straight rod, The other end of the anchor is a free end and extends in the direction of the proximal end.
The filter according to claim 14, wherein an angle between said fixed anchor and said straight rod directly connected thereto is less than 90 degrees.
The filter according to claim 14, wherein a vertical distance of the free end of the anchor to the straight rod directly connected to the fixed anchor is less than or equal to 3 mm.
The filter according to claim 1, wherein the filter further comprises a recovery hook disposed at a telecentric end or a proximal end of the main body portion; the recovery hook is a tubular shape having an opening a structure in which an opening direction of the recovery hook extends outward in a radial direction of the filter and is offset toward the main body portion; a width of the opening of the recovery hook in a direction perpendicular to the opening is greater than or equal to Recovering 1/5 of the outer diameter of the tubular structure of the hook, the depth of the opening of the recovery hook in a direction perpendicular to the longitudinal central axis of the filter is less than or equal to 19/20 of the outer diameter of the tubular structure of the recovery hook .
The filter according to claim 1, wherein the filter is made of a nickel-titanium alloy, and the filter is formed by cutting the nickel-titanium tube to form the proximal end filter and the telecentric filter. The network cable is formed and shaped.