CN115644992A

CN115644992A - Thrombus taking bracket device

Info

Publication number: CN115644992A
Application number: CN202211388259.9A
Authority: CN
Inventors: 杨文广; 周求雄; 王玉强
Original assignee: Shanghai Hengchang Medical Technology Co ltd
Current assignee: Shanghai Hengchang Medical Technology Co ltd
Priority date: 2022-11-08
Filing date: 2022-11-08
Publication date: 2023-01-31
Anticipated expiration: 2042-11-08
Also published as: WO2024098970A1; CN115644992B

Abstract

The invention discloses a thrombus embolectomy support device, which comprises: an expanded stent comprising a proximal support portion and a distal dense mesh portion. The near-end supporting part comprises a plurality of near-end rods and a near-end grid formed by the plurality of near-end rods; the far-end dense net part comprises a plurality of far-end rods and a far-end grid consisting of the plurality of far-end rods; the number of the proximal rods is less than the number of the distal rods, and at least one of the rod length, the rod width and the rod wall thickness of the proximal rods is greater than the rod length, the rod width and the rod wall thickness of the distal rods. The near-end rod comprises a first connecting part and a second connecting part, and the first connecting part forms a binding end; the far-end rod comprises a third connecting part and a fourth connecting part, and the fourth connecting part forms a binding end; the second and third connecting portions are connected to each other such that the proximal support portion and the distal dense mesh portion are connected to each other to form a cage-like structure. The stent has larger radial supporting force, better vessel wall fitting performance and flexible operability required when treating large thrombus.

Description

Thrombus taking bracket device

Technical Field

The invention relates to a medical appliance, in particular to a thrombus thrombectomy support device for treating acute or subacute pulmonary embolism.

Background

Pulmonary embolism is the general term for a group of diseases or clinical syndromes in which the pulmonary circulation and right heart dysfunction are caused by the blockage of the pulmonary artery or its branches by endogenous or exogenous emboli. Thrombus caused by pulmonary embolism generally presents the characteristic of larger volume and is blocked at the positions of pulmonary artery trunks, the left pulmonary trunk, the right pulmonary trunk, and the branch arteries or branch arteries of the left pulmonary trunk and the right pulmonary branch. Acute or subacute thrombosis may lead to shock or hypotension in patients, with rapid changes in the patient's condition and clinical mortality as high as 15%.

The existing pulmonary embolism taking device is mainly implemented by a pure woven stent, or an auxiliary thrombus separation device in an aspiration catheter is adopted to assist thrombus aspiration, aiming at thrombus embolus which is slightly different from fresh thrombus or easily-obtained free floating thrombus, but aiming at slightly hard adherent embolus in subacute thrombus, the thrombus taking effect is not obvious. The woven stent can prevent the escape of thrombus, but is not ideal for obtaining subacute thrombus (two to four weeks after thrombus formation) or thrombus longer than a little (more than four weeks). The thrombus can not be captured and sucked out of the body by sucking the thrombus, and the catheter is easy to be blocked by the thrombus during suction, so that the catheter can not work normally.

Part of acute embolism can also be treated by means of thrombolysis or instant vessel opening by assisting thromboaspiration, most of pulmonary embolism is subacute thromboembolism, most of subacute thromboembolism patients are not satisfied with the treatment effect of thrombolysis or auxiliary aspiration, and the auxiliary aspiration and thrombus removal effect of the later novel braided stent or thrombus crushing device is not obvious.

As mentioned above, the current embolectomy device aiming at acute or subacute pulmonary embolism has very limited embolectomy effect on pulmonary thrombus with old and strong adhesive characteristics due to the structural limitation. Moreover, such thrombi often are accompanied by bulky features that do not allow them to be removed completely or at all with existing instruments.

Disclosure of Invention

Based on the current situation, aiming at acute or subacute pulmonary embolism with old characteristics of large volume and strong vessel adhesion, the invention at least solves the problems that the thrombus taking stent device has small internal space and poor vessel wall adhesion, and the operability is not flexible enough when large thrombus is treated in the operation.

In order to achieve the purpose, the invention also adopts the following technical scheme:

a thrombus thrombectomy stent device, comprising: an expansion stent comprising a proximal support portion and a distal dense mesh portion; the proximal support portion comprises a plurality of proximal rods and a proximal mesh formed by the plurality of proximal rods; the far-end dense-net part comprises a plurality of far-end rods and a far-end net formed by the far-end rods; the number of the proximal rods is less than that of the distal rods, and at least one of the rod length, the rod width and the rod wall thickness of the proximal rods is greater than that of the distal rods; the near-end rod comprises a first connecting part and a second connecting part, and the first connecting part forms a binding end; the far-end rod comprises a third connecting part and a fourth connecting part, and the fourth connecting part forms a binding end; the second and third connecting portions are connected to each other such that the proximal support portion and the distal dense mesh portion are connected to each other to form a cage-like structure.

As one embodiment of the invention, the pore diameter of the near-end grid of the thrombus thrombectomy stent device is larger than that of the far-end grid.

As an embodiment of the invention, the thrombus thrombectomy stent device proximal mesh comprises a first mesh part and a second mesh part, wherein the first mesh part is a mesh close to the first connecting part, and the second mesh part is a mesh close to the second connecting part; the apertures of the first mesh portion are larger than the apertures of the second mesh portion.

As one embodiment of the invention, the first connecting part of the thrombus thrombectomy stent device comprises three first proximal rods, wherein the rod width of each first proximal rod is 0.3-0.5mm, and the rod wall thickness is 0.15-0.5mm.

As one embodiment of the invention, the second connecting part of the thrombus thrombectomy stent device comprises a plurality of second proximal rods, the rod width of each second proximal rod is 0.15-0.5mm, and the rod wall thickness is 0.15-0.5mm; the number of second proximal rods is greater than the number of first proximal rods.

As one embodiment of the invention, one end of the first proximal rod of the thrombus thrombectomy stent device forms four branches, and each branch forms one second proximal rod.

As one embodiment of the invention, the thrombus thrombectomy stent device comprises a support rod on the proximal rod or the distal rod, and a developing structure is arranged on the support rod.

As one embodiment of the invention, the first connecting part of the thrombus thrombectomy stent device forms a converging end which is nested in the proximal developing ring.

As an embodiment of the invention, the restriction end formed by the fourth connecting part of the thrombus thrombectomy support device is nested in the noninvasive guide head.

As an implementation mode of the invention, the near-end supporting part and the far-end dense-net part of the thrombus thrombectomy stent device are both laser cutting structures; or the near-end supporting part is of a laser cutting structure, and the far-end dense net part is of a woven dense net structure.

In the technical scheme, the invention provides an improved thrombus extraction support device aiming at old thrombus with larger volume and stronger vessel adhesion, and the improved thrombus extraction support device simultaneously meets the requirements of larger internal space, better vessel wall fitting property, better radial supporting force and flexible and efficient operability required when large thrombus is treated in the operation.

Drawings

FIG. 1 is a schematic view of the overall construction of a thrombus treatment device;

FIG. 2 is a schematic view of a bracket mounting arrangement;

FIG. 3 is a schematic view of a stent structure;

FIG. 4 is a schematic view of a proximal support portion of the stent;

FIG. 5 is a schematic view of a portion of a stent distal end dense mesh;

FIG. 6 is a schematic view of a stent proximal mesh structure according to one embodiment of the present invention;

FIG. 7 is a schematic view of a stent proximal mesh structure according to another embodiment of the present invention;

FIG. 8 is a schematic view of a distal braided dense mesh stent;

FIG. 9 is a schematic illustration of a stent development configuration;

FIG. 10 is a schematic delivery view of the stent device;

FIG. 11 is a schematic view of the delivery of the stent device into position;

FIG. 12 is a schematic stent release diagram;

fig. 13 is a schematic illustration of stent embolectomy.

In the figure: 1-a stent device, 2-a delivery catheter, 3-a handle, 4-a non-invasive guide head, 5-an expansion stent, 6-an inner push rod, 7-a proximal end developing ring, 8-an outer push rod and 9-a developing structure. PE-clot material, BV-human blood vessels;

501-stent proximal end narrowing end rod, 502-first proximal rod, 503-second proximal rod, 504-second proximal rod, 505-second proximal rod, 514-developing strut, 515-second proximal rod, 516-second proximal rod, 517-second proximal rod, 518-second proximal rod, 509-first mesh portion, 510-second mesh portion, 519-first mesh portion, 520-second mesh portion, 521-second mesh portion, 524-second mesh portion, 522-stent proximal end support portion;

506-far-end rod, 507-far-end rod, 508-bracket far-end convergence end rod, 511-bracket far-end grid 1, 512-bracket far-end grid 2, 513-bracket far-end grid 3, 523-bracket far-end dense-net part.

Detailed Description

The technical solutions in the embodiments of the present invention are further clearly and completely described below with reference to the drawings and the embodiments. It is to be understood that the described embodiments are for the purpose of illustrating the subject invention and are not intended to be exhaustive of all embodiments of the subject invention.

Examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

It should be understood that "mounted," "connected," and "coupled" are intended to be inclusive and may, for example, be fixedly connected, removably connected, or integrally connected; can be mechanically or electrically connected; either directly or indirectly through intervening media, or through the communication between two elements. However, other words may be substituted by other expressions if they accomplish the same purpose.

As used in this specification and the appended claims, the terms "a," "an," "the," and/or "the" are not intended to be inclusive in the singular, but rather are intended to be inclusive in the plural, unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements.

In relation to the present description the terms "distal/distal" and "proximal/proximal", wherein proximal/proximal refers to the end closer to the operator and distal/distal refers to the end further away from the operator, or into a blood vessel of the human body.

Referring to fig. 1, the present invention discloses a stent device 1 which is installed near the top of a delivery catheter 2 of a thrombus treatment device, and the delivery catheter 2 is controlled by a handle 3, thereby further controlling the stent device 1. As shown in fig. 2 and 3, the stent device 1 mainly comprises an atraumatic head 4, an expansion stent 5, an inner push rod 6, a proximal end developing ring 7, an outer push rod 8, and the like. The stent device 1 is embedded in the delivery catheter 2, the inner push rod 6 is connected with the handle 3 and is connected with the stent distal end converging end 508 of the expansion stent 5, the outer push rod 8 is fixed with the handle 3, and the control on the size of the contour diameter of the stent 5 can be realized by adjusting the inner push rod 6 through the handle 3.

Referring to fig. 3, the main body of the stent device 1 is an expansion stent 5, and the expansion stent 5 is composed of a stent proximal end supporting part 522 and a stent distal end dense mesh part 523. As shown in fig. 3, the stent proximal end supporting portion 522 and the stent distal end dense-mesh portion 523 respectively include a plurality of interconnected supporting rods, wherein the supporting rod near the stent proximal end supporting portion 522 (i.e. the interconnected supporting rod extending from the stent proximal end supporting portion 522) is a proximal rod, and the supporting rod near the stent distal end dense-mesh portion 523 (i.e. the interconnected supporting rod extending from the stent distal end dense-mesh portion 523) is a distal rod. In addition, the proximal rods/the distal rods are respectively connected to each other to form a lattice structure, the lattice structure formed by the plurality of proximal rods is a proximal lattice, and the lattice structure formed by the plurality of distal rods is a distal lattice. With the lattice structure, the plurality of interconnected support rods form a unitary structure that is movable between a constrained state and an expanded state.

Referring to fig. 3-5, the expansion bracket 5 is structurally in the form of a shuttle or oval, and the outer contour size thereof is changed by the relative axial movement of the inner and outer push rods. From the overall structure, the area of the near-end grid unit is large, the area of the far-end grid unit is small, the near-end grid consists of two to six large-area units, and the adjacent large-area units are small-area units with the same number. The area of the distal mesh unit is small where each large mesh unit at the proximal end is mirror symmetric with respect to the central axis. In contrast, the far-end grid consists of units with the number being even multiple of the near-end large-area grid, the multiple is 2 to 6, and the sizes of the units of the far-end grid are basically consistent. The near-end grid unit and the far-end grid unit are connected through an I-shaped node, and the connecting node is the highest point of the outline of the expansion bracket 5. And the support outline developing marks are arranged beside the connecting nodes, and the number of the support outline developing marks is about 1 to 4 times of the number of the large grid units at the near end. Because the expansion bracket 5 is provided with the visible mark points under the clinical fluorescent image, the change size of the expansion bracket 5 can be clearly seen in the operation process.

As shown in fig. 3, although fig. 3 distinguishes the stent proximal end supporting section 522 and the stent distal end dense mesh section 523, the stent proximal end supporting section 522 formed of proximal rods and the stent distal end dense mesh section 523 formed of distal rods are connected to each other in a cage-like structure. Specifically, the proximal rod includes a first connection portion forming a constricted end, located at the left side portion as viewed in fig. 3, and a second connection portion. The distal rod includes a third connecting portion and a fourth connecting portion forming a converging end, located at the right side portion as shown in fig. 3. The second connection portion and the third connection portion are connected to each other at the central vertical line position shown in fig. 3, and the vertical line is used only as a mark for roughly dividing the stent proximal end support portion 522 and the stent distal end dense-mesh portion 523, and does not have a separate entity, and does not indicate a specific ratio of the stent proximal end support portion 522 and the stent distal end dense-mesh portion 523.

Referring to fig. 3, 4, 5 and 6, as an embodiment of the present invention, the stent proximal support portion 522 mainly includes one or more sets of a proximal bundling end rod 501, a first proximal end rod 502, a second proximal end rod 503, a second proximal end rod 504, a developing strut 514, and a second proximal end rod 505. Wherein the first proximal rod 502 is relatively thick, with a rod width dimension of between 0.3mm and 0.5mm, a stent wall thickness of between 0.15mm and 0.5mm, and a number of rods of between three and six. The second

proximal bars

503, 504 and 505 have a bar width of between 0.15mm and 0.5mm, a wall thickness of between 0.15mm and 0.5mm and a bar count of between 12 and 24. In one embodiment of the present invention, the number of developing struts 514 is generally half that of the second proximal shaft 504, but the present invention is not limited thereto.

With continued reference to fig. 3, 4, 5, and 6, the proximal converging end rod 501 is divided into three to six first proximal rods 502. Each first proximal rod 502 is further distally divided into two second proximal rods 503. Each second proximal rod 503 is further divided into two second proximal rods 504 toward the more distal end. Each secondary proximal rod 504 is further distally divided into two secondary proximal rods 505. The area formed by the connection of the five support rods (501, 502, 503, 504, 505) is a first grid part 509, and the first grid part 509 is relatively closer to the position of the first connection part, namely the proximal end narrowing end rod 501. The proximal rods that make up the three to six first mesh portions 509 make up the second connection portions of the expansion stent 5. The first proximal rod 502 is thicker and thicker than other support rods, which improves the rigid support of the large opening in the thrombus capture process, and improves the thrombus extraction efficiency. The first proximal shaft 502 has a smaller number of shafts and a longer shaft, which allows the expanded stent 5 to be more compliant into the delivery catheter 2, allowing the expanded stent 5 to be recycled.

The second proximal rod 503 and the second

proximal rods

504 and 505 may be branched to form (developing) stays, and developing structures are provided on the stays. As an embodiment of the present invention, one of every two second proximal rods 504 is branched into one developing strut 514 at a position slightly proximal to the branching of the second proximal rod 505, and the developing structure 9 is placed on the developing strut 514, as shown in fig. 9, but the present invention is not limited thereto. In other embodiments of the present invention, the developing struts may be disposed at other positions of the proximal rod (the first proximal rod, the second proximal rod) and/or the distal rod, which can achieve the technical objects of the present invention and achieve the technical effects of the present invention. As a second embodiment of the present invention, the developing structure 9 may be fixed to the second proximal shaft 504 by means of glue bonding, or may be fixed to the second proximal shaft 504 by means of laser welding. The visualization structure 9 may enable visualization of the expanded stent 5 under DSA (Digital subtraction angiography), which enables an operator to monitor the contour size of the expanded stent 5 within the vessel in real time. As a third embodiment of the present invention, the developing structure may be a bent structure as shown in fig. 9, an anchored hole structure, an i-beam structure, or other developing structure, which can achieve the technical object of the present invention and achieve the technical effect of the present invention, but the present invention is not limited thereto.

With continued reference to fig. 3-6, the second proximal rod 504 and the second proximal rod 505 of the stent proximal support section 522 form the second lattice section 510. The second

proximal rods

503, 504 and 505 constitute a second grid section 524. The portion of the proximal shaft of the expansion stent 5 constituting the second lattice section 510 and the second lattice section 524 is the second connection portion. The second connecting portion and the third connecting portion are connected to each other. The number of the support rods of the second connecting part is usually 12 to 24. Generally, the proximal shaft in the region of the first and second connectors is primarily used to capture, and separate thrombus from the vessel wall. The structure of the second grid part enables the expansion support 5 to have high radial supporting force, and better adherence can be provided with the blood vessel in the embolectomy process, so that more adherence emboli can be removed along the blood vessel wall by the expansion support 5, and embolectomy capacity which cannot be obtained by other embolectomy modes can be obtained.

Referring to fig. 7, as another embodiment of the present invention, the stent proximal supporting portion 522 is mainly composed of a proximal converging rod 501, a first proximal rod 502, a second proximal rod 515, a developing strut 514, a second proximal rod 516, a second proximal rod 517, and a second proximal rod 518. Wherein the first proximal rod 502 is relatively thick, having a rod width of between 0.3mm and 0.5mm, a stent wall thickness of between 0.15mm and 0.5mm, and a number of rods of between three and six. The second

proximal shafts

515, 516, 517, 518 have a shaft width of 0.15-0.5mm, a wall thickness of 0.15-0.5mm and a number of shafts between 12 and 24. In one embodiment of the present invention, the number of developing struts 514 is generally half that of the second proximal shaft 515, but the present invention is not limited thereto.

With continued reference to fig. 7, the proximal, converging end rod 501 is further distally divided into three first proximal rods 502. Each of the first proximal rods 502 is further divided into four second proximal rods, the outer two of which are second proximal rods 515 and the inner two of which are second proximal rods 518. The second proximal shaft 515 is divided into two second proximal shafts 516 toward the more distal end. The second proximal rod 518 is further divided into two second proximal rods 517. One of every two second proximal rods 515 has a developing strut 514 branched slightly near the branch of the second proximal rod 516, and the developing structure 9 is placed on the developing strut 514, as shown in fig. 9. In some examples, developer structure 9 may be secured to second proximal shaft 515 by glue bonding or may be secured to second proximal shaft 515 by laser welding. The area formed by the connection of the proximal converging rod 501, the first proximal rod 502, the second proximal rod 515 and the second proximal rod 516 is a first mesh portion 519, and the proximal rods forming three to six first mesh portions 519 form the first connection portion of the expansion stent 5.

With continued reference to FIG. 7, the second proximal shaft 515, the second proximal shaft 516, the second proximal shaft 517, the second proximal shaft 518 are connected to form a second mesh portion 520. The second proximal rod 517 and the second proximal rod 518 are connected to form a second mesh portion 521. In this embodiment, the portion of the proximal stem of the expansion stent 5 that constitutes the second mesh portion 520 and the second mesh portion 521 is the second connection portion. The second connecting portion and the third connecting portion are connected to each other.

As can be seen by comparing FIGS. 6 and 7, the number of the second proximal bars 515 extended from the first proximal bar 502 in the stent proximal supporting section 522 shown in FIG. 7 is changed from two in FIG. 6 to four in FIG. 7. Through a plurality of tests, the change in the quantity can bring stronger radial supporting force to the support near-end supporting part 522, and a better supporting effect is achieved. Those skilled in the art will appreciate that by adjusting the specific number and connection relationship of the first proximal shaft 502, the second proximal shaft 515, the second proximal shaft 516, the second proximal shaft 517 and the second proximal shaft 518, different radial support effects of the stent proximal support portion 522 can be obtained, and these different combinations and choices are within the scope of the present invention.

Referring to fig. 3 and 5, the stent distal dense mesh portion 523 is composed of a stent distal rod 506, a stent distal rod 507, and a stent distal convergent end rod 508. As an embodiment of the present invention, the width of the stent

distal end rods

506 and 507 and the stent distal end converging end rod 508 is between 0.15mm and 0.5mm, the thickness of the rod wall is between 0.15mm and 0.5mm, and the number of the rods is between 12 and 24, but the present invention is not limited thereto.

With continued reference to fig. 3 and 5. The second proximal bar 505 and the stent distal bar 506 constitute a stent distal lattice 511, and the stent distal bar 506 and the stent distal bar 507 constitute a stent distal lattice 512. Alternatively, in another example, the second proximal bars 516 and stent distal bars 506 form a stent distal lattice 511, and the stent distal bars 506 and stent distal bars 507 form a stent distal lattice 512. The distal rods that make up the stent distal mesh 511 and the stent distal mesh 512 together form a third connection. . The third connecting portion and the second connecting portion are connected to each other. The stent distal end rod 507 and the stent distal end narrowing end rod 508 form a stent distal end mesh 513 to form a distal end narrowing end, and the position of the stent distal end narrowing end rod 508 becomes a fourth connection portion of the expansion stent 5. The stent distal end meshes 511, 512 and 513 are in a dense mesh shape, and the expanded shape thereof is in a form in which the area of the mesh gradually decreases from the top of the expanded stent toward the distal end. The aperture of the far-end grid is smaller than that of the near-end grid, so that the grabbed thrombus can be firmly enclosed in the stent, and the thrombus is prevented from escaping.

As can be seen from fig. 3-8, in the present invention, the number of proximal rods of the expansion stent 5 is smaller than the number of distal rods, and at least one of the rod length, the rod width and the rod wall thickness of the proximal rods is larger than that of the distal rods. This "asymmetric" form is assumed, mainly for the following reasons:

1. the main function of the proximal rod and the stent proximal support portion 522 thereof is not to completely capture thrombus and prevent the thrombus from escaping, but also to play a role of better radial support, so that the proximal rod adopts a rod body which is longer, thicker and thicker in rod wall, and can have higher support strength and provide larger radial support force. In addition, the larger opening formed by the proximal rod also plays a better supporting effect due to the higher strength of the proximal rod, because the more and denser rods are not beneficial to improving the radial strength, but can weaken the radial strength;

2. the main function of the distal rod and its stent distal dense mesh portion 523 is to better capture thrombus and prevent thrombus from escaping, so the distal rod adopts a thinner and denser structure, thereby a dense mesh woven structure can be formed, and a hemispherical structure similar to a "basket" can make the stent distal dense mesh portion 523 better accommodate thrombus therein and prevent thrombus from escaping.

The expansion stent 5 may be made of a shape memory material such as nitinol, which may be manufactured by a variety of manufacturing methods. In some examples, the proximal stent support section 522 and the distal stent dense mesh section 523 may be made of the same material, in which a nickel-titanium tube is used to cut out the preliminary profile of the stent by a laser cutting machine, and then heat-set into the form of the expanded stent 5 shown in fig. 3-7. In other examples, the stent proximal support section 522 and the stent distal dense-mesh section 523 may be made of different materials, the stent proximal support section 522 is still made of a shape memory material such as nitinol, and a nitinol tube is used to cut the profile of the stent proximal support section 522 with a laser cutting machine. Unlike the stent proximal support section 522, the stent distal dense-mesh section 523 may be a woven dense-mesh structure, as shown in fig. 8. At this time, the stent distal dense mesh portion 523 is woven by a weaving method and then connected to a cutting stent having a relatively good proximal support by a processing method such as perforation, riveting or welding. When different materials are selected, the invention does not limit the stent proximal end supporting part 522 and the stent distal end dense mesh part 523.

With continued reference to fig. 1 to 2, the bracket proximal end narrowing stem 501 of the expansion bracket 5 is left with a sufficient length for connecting the external pushing rod 8. The stent distal end narrowing end rod 508 of the expansion stent 5 is left with enough length to connect the inner push rod 6 and the atraumatic head 4. The connection mode of the two ends of the expansion bracket 5 and the bracket device 1 can adopt Pebax material hot melting, and can also adopt a glue bonding mode. In a preferred embodiment of the present invention, the first connecting portion (where the proximal end stem 501 of the stent is located) forms a binding end that is nested in the proximal development ring 7, and the fourth connecting portion (where the distal end stem 508 of the stent is located) forms a binding end that is nested in the non-invasive head 4. The proximal developing ring 7, the non-invasive guide head 4 and the developing structure 9 cover the expansion bracket 5 from the proximal end, the middle part to the distal end, so that the expansion bracket 5 can display the whole dynamic state through the developing device in the using process.

When the present invention is involved in a surgical procedure, referring to fig. 10, a stent device 1 is introduced into a human blood vessel BV through a delivery catheter 2 and in proximity to the location of a thrombus PE. The outer push rod 8, the inner push rod 6 and the expansion bracket 5 are pushed out of the delivery catheter 2 under the control of the handle 3.

Referring to fig. 11, until the expanded stent 5 is delivered to the thrombus PE distal end position, the expanded stent 5 remains constrained within the delivery catheter 2 as shown by the minimum profile diameter.

Referring to fig. 12, when the expansion stent 5 is at the position distal to the thrombus PE, the relative axial spacing of the outer pusher rod 8 and the inner pusher rod 6 is changed by the handle 3, thereby changing the diameter of the expansion stent 5 from the constrained state to the deployed state. The expanded stent 5 may not be properly deployed during the surgical operation, and the expanded stent 5 may be withdrawn into the delivery catheter 2 again, and the expanded stent 5 may be released again as the stent device 1 adjusts the release position of the expanded stent 5, so that the expanded stent 5 can be recycled. After deployment of the expandable stent 5 in place, it is adjusted by the handle 3 to a size of the overall diameter to accommodate the diameter of the blood vessel BV. The developing structure 9 can enable the expansion bracket 5 to have a developing effect under DSA (Digital subtraction angiography), can monitor the contour size of the expansion bracket 5 in the blood vessel in real time, and assists a surgeon in thrombus removal.

Referring to fig. 13, when the expanded stent 5 is deployed for thrombectomy, the expanded stent 5 is pulled proximally out of the blood vessel BV controlled by the handle 3. The expanded stent 5 captures and scrapes the thrombus PE on the wall of the blood vessel BV during the dragging process. The third connecting part and the fourth connecting part of the far end of the stent are of dense-mesh grid structures, so that the captured thrombus can be firmly enclosed in the stent, and the thrombus is prevented from escaping. The thrombus PE is pulled to the vicinity of the suction port at the far end of the suction catheter or is pulled into the suction catheter along with the handle 3 and the expansion stent 5 from the blood vessel BV, so that the suction catheter sucks out the thrombus PE, or the thrombus PE is directly pulled out of the body through the suction catheter until the thrombus is completely removed out of the body, thereby realizing stent thrombus removal.

After the stent is completely thrombus-taking out, the delivery catheter 2, the outer push rod 8, the inner push rod 6 and the expansion stent 5 are drawn out from the human body blood vessel BV through the handle 3, so that the whole thrombus-taking out process is completed.

In conclusion, the thrombus embolectomy support device has the following beneficial effects:

1) The hollow basket support designed based on the shape memory alloy can be a mesh cutting support distributed in a rod shape, and can also be a support formed by mixing the mesh cutting support and a weaving support, has the characteristics of large opening at the near end and good support property, is convenient for capturing and removing massive thrombus, can not collapse at the near end in the thrombus taking process, and has higher thrombus taking effectiveness aiming at the heavy-load thrombus;

2) The radial force of the stent is large, so that the adherence of the stent and the blood vessel is stronger, the stent is convenient to capture thrombus attached to the blood vessel wall, and the thrombus can be removed more completely;

3) The distal end of the stent adopts a cutting or weaving dense net structure, so that thrombus captured by the stent cannot escape, and blockage caused by escaping thrombus is avoided;

4) The spherical or cage-shaped design of the bracket ensures that the inner part of the bracket has a larger thrombus storage space, but can still keep higher radial supporting force, so that the thrombus accommodating capacity of the bracket is improved, and the thrombus taking efficiency is higher;

5) The stent can meet the size of the corresponding blood vessel by following the adjustment of the handle, and simultaneously can play a role of destroying thrombus by matching with the adjustment of the handle, and one stent can adapt to the thrombus removal in a wider range of blood vessel diameters;

6) The maximum outer diameter of the stent is provided with a developing structure design, the current size of the stent can be judged by looking up DSA images in the operation, and the size of the stent can be adjusted by a handle to realize the adjustment and adaptation of the stent and the diameter of the blood vessel. Or the whole body structure can be developed, and the inner layer or the outer layer is coated to develop and weave the bracket;

7) The stent has excellent sheathing performance and can be recovered, and when the stent release position is not proper, the stent can be regulated to the sheathing size and enter the sheath tube to regulate the stent release position again;

8) The support can cooperate great suction pipe bore to realize suction and support and unite the thrombectomy for pulmonary embolism extraction efficiency obtains more promotion, makes the thrombectomy more thorough, increases the thrombectomy validity. It should be understood by those skilled in the art that the above embodiments are only for illustrating the present invention and are not to be used as a limitation of the present invention, and that changes and modifications to the above described embodiments are within the scope of the claims of the present invention as long as they are within the spirit and scope of the present invention.

Claims

1. A thrombus thrombectomy support device, which is characterized by comprising:

an expansion stent comprising a proximal support portion and a distal dense mesh portion;

the proximal support portion comprises a plurality of proximal rods and a proximal mesh formed by the plurality of proximal rods;

the far-end dense-net part comprises a plurality of far-end rods and a far-end grid formed by the far-end rods;

the number of the proximal rods is less than that of the distal rods, and at least one of the rod length, the rod width and the rod wall thickness of the proximal rods is greater than that of the distal rods;

the proximal rod comprises a first connecting part and a second connecting part, and the first connecting part forms a binding end;

the distal rod comprises a third connecting part and a fourth connecting part, and the fourth connecting part forms a binding end;

the second and third connectors are interconnected such that the proximal support section and the distal dense mesh section are interconnected to form a cage-like structure when the expanded stent is in a released state.

2. A thrombectomy stent device according to claim 1, wherein:

the aperture of the near-end grid is larger than that of the far-end grid.

3. A thrombus thrombectomy stent device according to claim 1, wherein:

the proximal mesh comprises a first mesh portion and a second mesh portion, wherein the first mesh portion is a mesh adjacent to the first connection portion and the second mesh portion is a mesh adjacent to the second connection portion;

the apertures of the first mesh portion are larger than the apertures of the second mesh portion.

4. A thrombectomy stent device according to claim 3, wherein:

the first connecting part comprises three first near-end rods, the rod width of each first near-end rod is 0.3-0.5mm, and the rod wall thickness is 0.15-0.5mm.

5. A thrombectomy stent device according to claim 4, wherein:

the second connecting part comprises a plurality of second near-end rods, the rod width of each second near-end rod is 0.15-0.5mm, and the rod wall thickness is 0.15-0.5mm;

the number of the second proximal rods is greater than the number of the first proximal rods.

6. A thrombus thrombectomy stent device according to claim 5, wherein:

one end of the first proximal rod forms four prongs, each of which forms one of the second proximal rods.

7. The thrombectomy stent device of any one of claims 1-6, further comprising:

the developing structure comprises a supporting rod on the near-end rod or the far-end rod, and the developing structure is arranged on the supporting rod.

8. A thrombectomy stent device according to any one of claims 1-6, further comprising:

the contraction end formed by the first connecting part is nested in the near-end developing ring.

9. A thrombectomy stent device according to any one of claims 1-6, wherein:

the beam-collecting end formed by the fourth connecting part is nested in the noninvasive guide head.

10. A thrombectomy stent device according to any one of claims 1-6, wherein:

the near-end supporting part and the far-end dense net part are both of laser cutting structures; or,

the near-end supporting part is of a laser cutting structure, and the far-end dense net part is of a woven dense net structure.