Vena cava filter

Abstract

The vena cava filter comprises a conveying pipe, a pushing pipe, a filter screen and an expander, a cover cap is arranged at the far end of the conveying pipe, an opening is formed in the cover cap, the pushing pipe is movably inserted into the conveying pipe relatively, the expander is movably inserted into the conveying pipe and the filter screen, and the filter screen has a containing state and a working state. When the filter screen is in a storage state, the filter screen is located in the conveying pipe and is folded into a pipe shape, when the filter screen is in a working state, the filter screen is located outside the far end of the conveying pipe and is self-expanded into a funnel shape, the pushing pipe is used for pushing the filter screen to enable the filter screen to extend out of the far end of the conveying pipe, and the cap is pushed by the filter screen to deform, so that the opening is enlarged. And the maximum inner diameter of the enlarged opening does not exceed the inner diameter of the conveying pipe. According to the utility model, the delivery tube, the pushing tube, the filter screen and the dilator are coaxial and integrated, so that the operation is more convenient, and the risk that the far end of the delivery tube shovels the blood vessel wall in the pushing process can be avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to medical instrument technical field, concretely relates to a vena cava filter. BACKGROUND

[0002] Vena cava filter is a kind of medical instrument specially designed to prevent the occurrence of arterial embolism. It can be implanted in vena cava, intercepts the embolus possibly dropped in limb venous, to prevent the embolus into pulmonary artery, to prevent the occurrence of pulmonary embolism (PE). The main principle of this device is to place a filter screen in the vena cava to capture and prevent the upward of lower extremity venous thrombosis to the pulmonary artery, to prevent the occurrence of pulmonary embolism.

[0003] The existing conventional vena cava filter includes filter screen, long sheath tube, dilator matched with long sheath tube and conveyor matched with long sheath tube, when filter screen is implanted, dilator needs to be inserted into long sheath tube first, after the distal end of long sheath tube reaches the specified position, dilator is withdrawn, filter screen is inserted into long sheath tube with conveyor, filter screen is released from the distal end of long sheath tube to the specified position, and the operation is more cumbersome. If the specification of dilator is adjusted, so that dilator can be provided in conveyor and filter screen, and dilator, conveyor and filter screen are simultaneously pushed in blood vessel with long sheath tube, the operation can be simplified, but due to the specification adjustment of dilator, dilator cannot be attached to long sheath tube, and the distal end edge of long sheath tube is easy to shovel the blood vessel wall in the process of conveying. SUMMARY

[0004] The utility model aims at providing a kind of vena cava filter with simple structure, easy operation, and can reduce the risk of shoveling blood vessel wall in the process of pushing.

[0005] To achieve the above-mentioned purpose, the utility model employs the technical scheme that:

[0006] A vena cava filter includes a delivery tube, a push tube, a filter screen, and a dilator. The distal end of the delivery tube is provided with a cap, the cap is provided with an opening, the push tube is movably inserted into the delivery tube, the dilator is movably inserted into the push tube and the filter screen, the filter screen has a storage state and a working state, when the filter screen is in the storage state, it is located inside the delivery tube and is folded into a tubular shape, when the filter screen is in the working state, it is located outside the distal end of the delivery tube and is self-expanded into a funnel shape, the push tube is used to push the filter screen, the filter screen pushes the cap, the cap is deformed under the push of the filter screen, so that the opening becomes larger, the filter screen extends out of the opening and changes into the working state, and the maximum inner diameter of the opening after becoming larger does not exceed the inner diameter of the delivery tube.

[0007] The utility model discloses a special structure's cap is arranged at the far -end of the conveying pipe, and the conveying pipe, push pipe, filter screen and dilator are arranged as coaxial integral structure, and one -time delivery is used, need not send into filter and push pipe again after taking out dilator, and the operation is more convenient, and the cap structure can also avoid the risk that the far -end of conveying pipe is wounded in the pushing process in the blood vessel wall, also does not hinder the filter screen and sends out.

[0008] In the embodiment of the utility model, the cap is in the circular truncated cone type structure, and the inner diameter gradually decreases from the proximal end to the distal end.

[0009] In the embodiment of the utility model, the cap is enclosed by multiple cap elements in the shape of a trapezoid.

[0010] Specifically, a TIP head can be formed or fixedly connected at the distal end of the conveying pipe first, and then the TIP head is cut to form the structure of the cap. Multiple slits extending from the proximal end to the distal end can be sequentially and spacedly drawn on the side wall of the TIP head in the circumferential direction, thereby forming multiple cap elements. Alternatively, multiple cap elements can be integrally formed or fixedly connected at the distal end of the conveying pipe, and the multiple cap elements can be designed to be capable of moving closer to each other or moving away from each other at the distal end.

[0011] According to some specific embodiments of the utility model, the cap elements are provided with magnetic sheets, and multiple cap elements are enclosed to form the cap through magnetic attraction.

[0012] In the embodiment of the utility model, when the filter screen is in the working state, the inner diameter gradually increases from the proximal end to the distal end and then remains unchanged.

[0013] The filter screen in the utility model is a self-expanding filter screen. After self-expanding, the part of the filter screen with an unchanged inner diameter is tightly attached to the blood vessel wall, and the contact area with the blood vessel wall is large after placement. Therefore, the filter screen does not need to be riveted to the blood vessel wall, and the damage to the blood vessel wall is small.

[0014] In some embodiments of the utility model, the filter screen and the push pipe are arranged separately. After the filter screen is completely pushed out of the conveying pipe, the filter screen is separated from other components and can be left in the blood vessel alone. The filter screen can be designed as a permanent filter or a recyclable filter. By selecting a suitable existing recycling device, the filter screen in the utility model can also be recycled.

[0015] In some other embodiments of the utility model, the proximal end of the filter screen is fixedly connected to the distal end of the push pipe. That is, the filter screen can be designed as a temporary filter. After use, the filter screen can be retracted into the conveying pipe through the relative movement between the conveying pipe and the push pipe.

[0016] In the embodiment of the utility model, the dilator includes dilator body and the puncture part of setting at the distal end of dilator body, along the axial direction of dilator, the outer diameter of dilator body keeps constant, the outer diameter of puncture part gradually reduces from proximal end to distal end, and the proximal end outer diameter of puncture part is equal to the outer diameter of dilator body, the minimum inner diameter of opening is substantially equal to the outer diameter of dilator body.

[0017] In the embodiment of the utility model, the cap is provided with a developing point or a developing coating, which can be used by the operator to judge the opening and closing condition of the cap.

[0018] Further, the developing point or the developing coating can be provided on each cap element to more accurately and comprehensively display the opening and closing condition of the cap.

[0019] In the embodiment of the utility model, the material of the delivery tube and / or the cap is a high polymer material, a metal material or a high polymer metal composite material. Preferably, the cap is made of a flexible material.

[0020] Preferably, the delivery tube is a high polymer tube, a metal tube or a high polymer metal composite tube.

[0021] Specifically, the high polymer material includes but is not limited to PTFE, PU, Pebax, nylon, TPU and PE; the metal material includes but is not limited to stainless steel and nickel-titanium alloy. The high polymer metal composite tube includes but is not limited to a braided tube, a coiled spring tube, a snake bone tube, a hypotube or a combination tube of two or more of the above.

[0022] In the embodiment of the utility model, the material of the delivery tube and the cap is the same or different.

[0023] In the embodiment of the utility model, the delivery tube and the cap are integrally formed or fixedly connected.

[0024] In the embodiment of the utility model, the material of the push tube is a high polymer material, a metal material or a high polymer metal composite material. The material of the push tube is the same as or different from the material of the delivery tube.

[0025] In the embodiment of the utility model, the material of the filter screen is a metal or a high polymer material. The metal material includes but is not limited to cobalt-chromium-nickel-molybdenum-iron, nickel-titanium and cobalt-chromium. The high polymer material includes but is not limited to polylactic acid, polyglycolide and polycaprolactone. Preferably, the filter screen is made of a nickel-titanium alloy wire or cut from a nickel-titanium alloy tube.

[0026] In the embodiment of the utility model, the material of the dilator is a developing elastic high polymer material.

[0027] Specifically, the dilator is made of elastic polymer doped with a certain proportion of developing material, for example, in the utility model, the dilator is injection molded by PE and BaSO4 mixed developing material, and the mass percentage of BaSO4 is 5-12%.

[0028] In the embodiment of the utility model, the vena cava filter further comprises an operation handle arranged at the proximal end of the delivery tube, the push tube and the dilator, and an operation assembly capable of driving the delivery tube to move relative to the push tube and arranged on the operation handle.

[0029] In some specific embodiments of the utility model, the operation handle reserves a certain space in the axial direction of the delivery tube, so that the proximal end of the delivery tube is always located in the operation handle during the pushing and retracting process.

[0030] The operation assembly can use the assembly commonly used in the art that can drive the relative movement of two coaxially arranged tubes, and there is no special limitation in the utility model, and preferably, the operation assembly is designed to be controlled by a button, and when the button is pushed in one direction, the delivery tube is driven to be retracted towards the proximal end relative to the push tube, and when the button is pushed in the other direction, the delivery tube is driven to be pushed towards the distal end relative to the push tube.

[0031] In the embodiment of the utility model, the operation handle is further provided with a suction catheter communicated with the proximal end of the delivery tube and / or the push tube, and the proximal end of the suction catheter can be connected to a suction device, so that the blood clots in the filter screen can be sucked through the suction device after the dilator is withdrawn.

[0032] Thanks to the above technical scheme, the utility model has the following advantages compared with the prior art:

[0033] The utility model sets a special structure cap at the distal end of the delivery tube, and sets the delivery tube, the push tube, the filter screen and the dilator as a coaxial integrated structure, and the delivery tube, the push tube, the filter screen and the dilator are delivered at one time, and the dilator does not need to be withdrawn before the filter and the push tube are sent, the operation is more convenient, and the cap structure can also avoid the risk of damaging the blood vessel wall during the pushing process, and does not hinder the filter screen from being sent out. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a structure schematic view of the vena cava filter of embodiment 1 before the filter screen is released.

[0035] Figure 2 It is an enlarged view of A in the middle. Figure 1 ​

[0036] Figure 3 Fig. 1 is a perspective view of a vena cava filter according to an embodiment of the present application; Figure 1 Fig. 2 is a perspective view of the vena cava filter of Fig. 1 with the dilator removed;

[0037] Figure 4 Fig. 3 is a perspective view of the dilator in the vena cava filter of Fig. 1 ;

[0038] Figure 5 Fig. 4 is a perspective view of the vena cava filter of Fig. 1 with the filter basket fully deployed and the dilator partially withdrawn;

[0039] Figure 6 Fig. 5 is a perspective view of the vena cava filter of Fig. 1 with the filter basket fully deployed and the dilator fully withdrawn;

[0040] Figure 7 Fig. 6 is a perspective view of the vena cava filter of Fig. 1 with the filter basket fully deployed and the dilator fully withdrawn; Figure 6 Fig. 7 is an enlarged view of area B in Fig. 6.

[0041] Fig. 8 is a perspective view of the vena cava filter of Fig. 1 with the filter basket fully deployed and the dilator fully withdrawn;

[0042] 1 delivery tube, 11 cap; 111 cap element; 112 magnetic sheet; 113 radiopaque marker; 2 push tube; 3 filter basket; 31 first portion; 32 second portion; 4 dilator; 41 dilator body; 42 puncture portion; 5 handle; 51 actuation button; 52 aspiration conduit. DETAILED DESCRIPTION

[0043] The present application will be further described with reference to the drawings of the embodiments shown therein.

[0044] In the following, only certain exemplary embodiments are described in brief. As will be realized by those skilled in the art, the described embodiments can be modified in various different ways without departing from the spirit or scope of embodiments of the present application. Therefore, the drawings and descriptions are to be regarded as illustrative in nature and not as restrictive.

[0045] In the description of the present application, it needs to be understood that "distal end" refers to the end of an instrument or component that is far away from an operator (e.g. a medical staff), "proximal end" refers to the end of an instrument or component that is close to an operator (e.g. a medical staff), "axial direction" refers to the direction parallel to the center line of the distal end and the proximal end of an instrument or component, "inner" and "outer" are defined as the position relative to the center of an instrument or component, wherein "inner" is the position close to the center of an instrument or component, and "outer" is the position far away from the center of an instrument or component. The above descriptions of the orientation words are only for the convenience of describing the embodiments of the present application and simplifying the description, and are not indicative or suggestive of the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0046] In the description of the embodiments of the present application, it should be understood that the terms "first", "second" are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0047] In the present application, unless otherwise specifically defined and limited, in the description of the present application, unless otherwise specifically defined and limited, the terms "connected", "fixed" and the like should be understood in a broad sense, for example, can be fixedly connected, or integrated. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0048] The following disclosure provides many different embodiments or examples for implementing different structures of the embodiments of the present application. In order to simplify the disclosure of the embodiments of the present application, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the embodiments of the present application. In addition, the embodiments of the present application can repeatedly refer to numbers and / or letters in different examples, and such repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed.

[0049] Embodiment 1

[0050] As shown in Figures 1-7 The present embodiment provides a vena cava filter, which comprises a delivery tube 1, a push tube 2, a filter screen 3, a dilator 4 and an operating handle 5. Specifically, the push tube 2 is movably inserted in the delivery tube 1, the dilator 4 is movably inserted in the push tube 2 and the filter screen 3, the filter screen 3 has a storage state and a working state, when the filter screen 3 is in the storage state, it is located inside the delivery tube 1 and is folded into a tubular shape, when the filter screen 3 is in the working state, it is located outside the distal end of the delivery tube 1 and is self-expanded into a funnel shape, the push tube 2 is used to push the filter screen 3, the filter screen 3 pushes the cap 11, the cap 11 is deformed under the pushing of the filter screen 3, so that the opening becomes larger, the filter screen 3 extends out of the opening and converts into the working state, the maximum inner diameter of the opening after becoming larger does not exceed the inner diameter of the delivery tube 1, and the minimum inner diameter of the opening before becoming larger is substantially equal to the outer diameter of the dilator 4.

[0051] In the embodiment, the delivery tube 1 is a hollow tube with both ends open and a constant inner diameter. The distal end of the delivery tube 1 is provided with a cap 11, which has a variable opening with an inner diameter not exceeding that of the delivery tube 1. The cap 11 is in the shape of a circular truncated cone, with the inner diameter gradually decreasing from the proximal end to the distal end. The cap 11 is formed by a plurality of substantially trapezoidal cap elements 111, each provided with a magnetic sheet 112. The cap elements 111 are enclosed by magnetic attraction to form the cap 11. In the embodiment, the delivery tube 1 is a polymer tube, specifically made of Nylon by injection molding. A flexible TIP head is fixedly connected to the distal end of the delivery tube 1. A plurality of slits extending from the proximal end to the distal end are then formed on the sidewall of the TIP head in a circumferential direction, thereby forming a plurality of cap elements 111. A magnetic sheet 112 and a development point 113 for the surgeon to determine the opening of the cap 11 are fixedly arranged on each cap element 111. In the embodiment, the number of cap elements 111 is six, which can be adjusted according to actual needs in other embodiments. Of course, in other embodiments, other materials can be selected for the delivery tube 1, and the cap 11 can be provided on the distal end of the delivery tube 1 in other ways. For example, the delivery tube 1 can also be a metal tube or a polymer-metal composite tube. The material of the cap 11 can be the same as or different from that of the delivery tube 1, but the cap 11 is preferably flexible. For another example, a plurality of cap elements 111 can be integrally formed or fixedly connected to the distal end of the delivery tube 1, and the plurality of cap elements 111 can be designed to be able to move closer to or away from each other at the distal end.

[0052] In the embodiment, the push tube 2 is a hollow tube with both ends open and a constant inner diameter. The push tube 2 is coaxial with the delivery tube 1, and the material of the push tube 2 is the same as that of the delivery tube 1. In the embodiment, the distal end of the push tube 2 is not directly connected to the proximal end of the filter screen 3.

[0053] In the embodiment, the filter screen 3 is composed of a first part 31 and a second part 32. When the filter screen 3 is in a working state, the inner diameter of the first part 31 gradually increases from the proximal end to the distal end, and the inner diameter of the second part 32 remains constant and is equal to the inner diameter of the distal end of the first part 31. In the embodiment, the filter screen 3 is not directly connected to other components, and it can be permanently implanted or recovered after a period of implantation by a suitable existing recovery device in the art. In the embodiment, the filter screen 3 is made of a nickel-titanium alloy wire. In other embodiments, the filter screen 3 can be cut from a nickel-titanium alloy tube or made of other polymer materials.

[0054] In the embodiment, the dilator 4 comprises a dilator body 41 and a puncture part 42 arranged at the distal end of the dilator body 41. The outer diameter of the dilator body 41 remains unchanged along the axial direction of the dilator 4, the outer diameter of the puncture part 42 gradually decreases from the proximal end to the distal end, the proximal end of the puncture part 42 has the same outer diameter as the dilator body 41, and the outer diameter of the dilator body 41 is substantially equal to the minimum inner diameter of the opening. In the embodiment, the dilator 4 is injection molded by a developing material formed by mixing PE and BaSO4, and the mass percentage of BaSO4 is 10%. In other embodiments, the dilator 4 can be made of suitable developing material according to actual needs.

[0055] In the embodiment, the operation handle 5 is arranged at the proximal end of the delivery tube 1, the push tube 2 and the dilator 4. The operation handle 5 is provided with an operation assembly capable of driving the delivery tube 1 to move relative to the push tube 2. Specifically, the operation handle 5 reserves a certain space along the axial direction of the delivery tube 1, so that the proximal end of the delivery tube 1 is always located in the operation handle 5 during the pushing and retracting process. In the embodiment, the operation assembly uses a common assembly in the art capable of driving the relative movement of two coaxially arranged tubes, which is not particularly limited and will not be described here. In the embodiment, the operation assembly is designed to be controlled by a button 51. When the button 51 is pushed in one direction, the delivery tube 1 is driven to retract relative to the push tube 2 towards the proximal end. When the button 51 is pushed in the other direction, the delivery tube 1 is driven to push relative to the push tube 2 towards the distal end. In the embodiment, the operation handle 5 is also provided with a suction guide tube 52 in communication with the proximal end of the delivery tube 1 and the push tube 2. The proximal end of the suction guide tube 52 can be connected to a suction device. After the dilator 4 is withdrawn, the blood clots in the filter 3 can be suctioned through the suction device. Of course, in other embodiments, a suitable existing suction guide tube 52 can also be sent through another passage.

[0056] The vena cava filter of the embodiment is packaged separately when it leaves the factory. The delivery tube 1, the push tube 2, the filter 3 and the operation handle 5 are assembled together. Before use, the dilator 4 is sequentially inserted into the push tube 2 and the filter 3 from the operation handle 5. The puncture part 42 of the dilator 4 penetrates the cap 11 to expose the distal end of the delivery tube 1. During use, the jugular vein is punctured, and the puncture part 42 is inserted into the subclavian vein, the superior vena cava, the right atrium and the inferior vena cava to the designated position. After the handle button is pushed, the delivery tube 1 is retracted, the filter 3 is released, the handle button is pushed forward to push the delivery tube 1, the distal end of the push tube 2 is retracted into the delivery tube 1, the proximal end of the dilator 4 is pulled backward, the puncture part 42 of the dilator 4 is retracted into the delivery tube 1, the push tube 2 and the dilator 4 are withdrawn together with the delivery tube 1, and the implantation of the filter 3 is completed. The filter 3 can be permanently implanted or retrieved through a suitable retrieval device after a period of implantation. Of course, the dilator 4 can also be movably inserted into the operation handle 5, the push tube 2 and the filter 3 when it leaves the factory.

[0057] Embodiment 2

[0058] The temporary vena cava filter of this embodiment is basically the same as that of embodiment 1, with the difference being that the proximal end of the filter screen 3 is fixedly connected to the distal end of the push tube 2. The method of using the temporary vena cava filter of this embodiment is the same as that of embodiment 1, with the difference being that after the filter screen 3 is released, the proximal end of the filter screen 3 is still connected to the push tube 2, and when the push tube 2 is subsequently pushed forward by actuating the handle button, the distal end of the push tube 2 is retracted into the delivery tube 1, the filter screen 3 is retracted into the delivery tube 1 at the same time, and the filter screen 3 is withdrawn together with the other components.

[0059] The above embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made in accordance with the spirit and essence of the present application shall be covered within the protection scope of the present application.

Claims

1. A vena cava filter, characterized in that, The vena cava filter includes a delivery tube (1), a push tube (2), a filter screen (3), and a dilator (4). The distal end of the delivery tube (1) is provided with a cap (11) having an opening. The push tube (2) is relatively movably inserted into the delivery tube (1). The dilator (4) is movably inserted into the push tube (2) and the filter screen (3). The filter screen (3) has a retracted state and a working state. When the filter screen (3) is in the retracted state, it is located in the delivery tube (1)... The internal parts are folded into a tubular shape. When the filter (3) is in the working state, it is located outside the far end of the conveying pipe (1) and expands into a funnel shape. The push pipe (2) is used to push the filter (3), and the filter (3) pushes the cap (11). The cap (11) is deformed by the push of the filter (3), making the opening larger. The filter (3) extends out from the opening and changes to the working state. The maximum inner diameter of the opening after it is enlarged does not exceed the inner diameter of the conveying pipe (1).

2. The vena cava filter according to claim 1, characterized in that, The cap (11) has a frustum-shaped structure, and its inner diameter gradually decreases from its proximal end to its distal end.

3. The vena cava filter according to claim 1, characterized in that, The cap (11) is formed by multiple generally trapezoidal cap elements (111).

4. The vena cava filter according to claim 3, characterized in that, The cap element (111) is provided with a magnetic sheet (112), and multiple cap elements (111) are gathered together by magnetic attraction to form the cap (11).

5. The vena cava filter according to claim 1, characterized in that, When the filter (3) is in the working state, its inner diameter gradually increases from its proximal end to its distal end and then remains constant.

6. The vena cava filter according to claim 1, characterized in that, The filter (3) and the push tube (2) are separately configured, or the proximal end of the filter (3) is fixedly connected to the distal end of the push tube (2).

7. The vena cava filter according to claim 1, characterized in that, The dilator (4) includes a dilator body (41) and a puncture portion (42) disposed at the distal end of the dilator body (41). Along the axial direction of the dilator (4), the outer diameter of the dilator body (41) remains constant, the outer diameter of the puncture portion (42) gradually decreases from the proximal end to the distal end, and the proximal outer diameter of the puncture portion (42) is equal to the outer diameter of the dilator body (41). The minimum inner diameter of the opening is approximately equal to the outer diameter of the dilator body (41).

8. The vena cava filter according to claim 1, characterized in that, The cap (11) is provided with developing dots or developing coating; And / or, the material of the conveying pipe (1) and / or the cap (11) is a polymer material, a metal material or a polymer-metal composite material, the material of the conveying pipe (1) and the cap (11) is the same or different, and the conveying pipe (1) and the cap (11) are integrally formed or fixedly connected; And / or, the filter screen (3) is made of nickel-titanium alloy or polymer material; And / or, the expander (4) is made of a developable elastic polymer material.

9. The vena cava filter according to claim 1, characterized in that, The vena cava filter further includes an operating handle (5) disposed at the proximal end of the delivery tube (1), the push tube (2) and the dilator (4), and an operating component disposed on the operating handle (5) capable of driving the delivery tube (1) to move relative to the push tube (2).

10. The vena cava filter according to claim 9, characterized in that, The operating handle (5) is also provided with a suction tube (52) that communicates with the proximal end of the delivery tube (1) and / or the push tube (2).

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