KR102452816B1 - Device for removing clot and method for removing clot using the same - Google Patents

Abstract

The present application relates to a thrombus removal device and a thrombus removal method using the same, a strut structure including a first tubular body and a second tubular body, a first proximal junction and a first distal junction of the first tubular body having a first length a second wire connected to and extending therebetween, the second wire being connected to, and extending therebetween, a second proximal junction and a second distal junction of a second tubular body having a first wire and a second length extending therebetween; one wire limits the distance between the first proximal junction and the first distal junction to within the first length, and the second wire limits the distance between the second proximal junction and the second distal junction to within the second length. A thrombus removal device is disclosed.

Description

A thrombus removal device and a thrombus removal method using the same {DEVICE FOR REMOVING CLOT AND METHOD FOR REMOVING CLOT USING THE SAME}

The present application relates to a thrombus removal device and a thrombus removal method using the same, and more particularly, to a thrombus removal device used for mechanical thrombectomy and a thrombus removal method using the same.

Ischemic vascular disease, one of the vascular diseases, is caused by a decrease in blood flow due to vessel occlusion or vascular stenosis. Therefore, for the treatment of ischemic vascular disease, it is most important to remove the thrombus from the blood vessel of the patient. In the past, dissolving blood clots by injecting a thrombolytic agent into a vein was a typical treatment method.

However, in clinical practice using mechanical thrombectomy, as the thrombus removal device such as a stent retriever is deformed during the thrombus recovery process, the thrombus escapes or fragments from the thrombus removal device, resulting in a decrease in the reperfusion rate, as well as a decrease in the reperfusion rate between the thrombus removal device and the vessel wall. There have been many reports of problems such as damage to the blood vessel wall due to the friction of

One object of the present invention is to provide a thrombus removal device and a thrombus removal method using the same, in which excessive deformation is suppressed during the thrombus removal process.

The problem to be solved by the present invention is not limited to the above-described problems, and the problems not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the present specification and the accompanying drawings. .

According to an aspect of the present invention, a strut structure comprising a first tubular body and a second tubular body disposed inside the first tubular body, one of the first tubular body and the second tubular body relative to the other slidable, wherein the strut structure is configured to open or close a mouse inviting a thrombus depending on the relative positions of the first tubular body and the second tubular body; having a first length and at a first proximal end a first wire extending to a distal end, the first proximal end being fixedly connected at a first proximal junction of a proximal end portion of the first tubular body, the first distal end being fixed to the first tubular body fixedly connected at a first distal junction with a distal end portion of a, wherein when the strut structure is unloaded, the first length is greater than a distance between the first proximal junction and the first distal junction - and a second length a second wire extending from a second proximal end to a second distal end having fixedly connected at a second distal junction with the distal end portion of the second tubular body, wherein when the strut structure is unloaded, the second length is greater than a distance between the second proximal junction and the second distal junction - wherein the first wire limits the distance between the first proximal junction and the first distal junction of the first tubular body to within the first length, and the second wire comprises: limiting the distance between the second proximal junction and the second distal junction to be within the second length, whereby the first wire and the second wire reduce the cross-sectional area of the strut structure and prevent a thrombus engaging the strut structure Provided is a thrombus removal device that prevents excessive stretching of the strut structure causing separation.

According to another aspect of the present invention, a strut structure comprising a plurality of cells having a predetermined boundary shape including two lengthwise ends and two circumferential ends and connected to the strut structure, recovering the strut structure from the blood vessel of the patient A thrombus removal device comprising a pull wire configured to receive (extracting, retrieving) manipulation, and configured to receive manipulation and move the strut structure along a longitudinal direction of the strut structure, wherein the plurality of cells correspond to the boundary wherein some of the plurality of cells extend linearly from one of the two longitudinal ends to the other of the two longitudinal ends, wherein the strut comprises an interior area defined by the boundary. further comprising a second strut element transverse to the longitudinal direction of the structure, wherein the second strut arrangement prevents an increase in length of some of the plurality of cells, wherein the increase in length causes movement in the longitudinal direction of the strut structure Occurs in the remainder of the plurality of cells that do not have the second strut configuration due to, thereby providing a thrombus removal device that reduces the change in length of the strut structure in the process of recovering some of the plurality of cells.

The solutions to the problems of the present invention are not limited to the above-described solutions, and solutions not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the present specification and the accompanying drawings. will be able

According to an embodiment of the present invention, an anti-stretching mechanism such as an anti-stretching wire or an anti-stretching structure cell suppresses excessive deformation of the stent body, thereby preventing separation or fragmentation of a thrombus bound to or captured by the thrombus removal device during the thrombus removal process This can improve the reperfusion rate.

In addition, according to an embodiment of the present invention, by suppressing excessive deformation of the stent body, friction applied to the vessel wall is minimized, thereby preventing damage to the vessel wall.

The effect of the present invention is not limited to the above-described effect, and the tasks not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the present specification and the accompanying drawings.

1 is a diagram illustrating an example of a shape deformation of a conventional thrombus removal device that occurs during a thrombus removal process.
2 is a view of another example of a shape deformation of a conventional thrombus removal device that occurs during a thrombus removal process.
3 is a view of thrombus fragmentation occurring in a conventional thrombus removal device.
4 is a view of a thrombus separation occurring in a conventional thrombus removal device.
5 is a diagram illustrating one example of a thrombus removal device according to one embodiment of the present specification.
6 is a diagram illustrating an operation of the thrombus removal device according to FIG. 5 .
7 is a diagram illustrating another example of a thrombus removal device according to an embodiment of the present specification.
8 is a diagram illustrating an operation of the thrombus removal device according to FIG. 7 .
9 is a diagram illustrating still another of the thrombus removal device according to an embodiment of the present specification.
FIG. 10 is a diagram illustrating an operation of the thrombus removal device according to FIG. 9 .
11 is a diagram illustrating another example (yet another) of the thrombus removal device according to an embodiment of the present specification.
12 is a diagram illustrating an operation of the thrombus removal device according to FIG. 11 .
13 is a view showing one implementation of the thrombus removal device according to an embodiment of the present specification.
14 is a diagram illustrating an embodiment of a thrombus removal device according to an embodiment of the present specification.
15 is a diagram illustrating an example of a thrombus removal device according to another embodiment of the present specification.
16 is a diagram illustrating another example of a thrombus removal device according to another embodiment of the present specification.
17 is a diagram illustrating an example of a thrombus removal device according to another embodiment (still another) of the present specification.
18 is a view of an example of a shape modification of the thrombus removal device according to FIG. 17 .
19 is a view related to another example of a shape deformation of the thrombus removal device according to FIG. 17 .
20 to 24 are diagrams of examples of a thrombus removal device according to another embodiment of the present specification.
25 is a view of an example of a thrombus removal device according to another embodiment (yet another) of the present specification.
26 and 27 are views illustrating different states of the thrombus removal device according to FIG. 25 .
28 is a side view of the operation of the thrombus removal device according to FIG. 25 .
29 is an exploded view of the operation of the thrombus removal device according to FIG. 25 .
30 is a view of an example of a shape modification of the thrombus removal device according to FIG. 25 .
31 to 35 are diagrams illustrating examples of a thrombus removal device according to another embodiment of the present specification.
36 is a diagram of an example of a thrombus removal device according to yet another embodiment of the present specification.
37 is an exploded view of the thrombus removal device according to FIG. 36 .
38 is a view of an example of an anti-stretching cell of the thrombus removal device according to FIG. 36 .
FIG. 39 is a view of another example of an anti-stretching cell of the thrombus removal device according to FIG. 36 .
40 is a view of another example of a thrombus removal device according to another embodiment of the present specification.
41 is an exploded view of the thrombus removal device according to FIG. 40 .
42 is a view of another example of a thrombus removal device according to another embodiment of the present specification.
43 is an exploded view of the thrombus removal device according to FIG. 42 .
44 is a view of another example of a thrombus removal device according to another embodiment of the present specification.
45 is a view of yet another example of a thrombus removal device according to another embodiment of the present specification.
46 is an example of an exploded view of the thrombus removal device according to FIG. 45 .
47 is another example of an exploded view of the thrombus removal device according to FIG. 45 .
48 is a view related to the thrombus removal device according to FIG. 47 .
49 is another example of an exploded view of the thrombus removal device according to FIG. 45 .
50 to 58 are views of various examples of a thrombus removal device according to another embodiment of the present specification.
59 is a flowchart of an example of a thrombus removal method according to an embodiment of the present specification.
60 is a flowchart of another example of a thrombus removal method according to an embodiment of the present specification.

The embodiments described in the present specification are for clearly explaining the spirit of the present invention to those of ordinary skill in the art to which the present invention belongs, so the present invention is not limited by the embodiments described herein, and the present invention It should be construed as including modifications or variations that do not depart from the spirit of the present invention.

The terms used in the present specification have been selected as widely used general terms as possible in consideration of the functions in the present invention, but they may vary depending on the intention, custom, or emergence of new technology of those of ordinary skill in the art to which the present invention belongs. can However, when a specific term is defined and used in an arbitrary sense, the meaning of the term will be separately described. Therefore, the terms used in this specification should be interpreted based on the actual meaning of the terms and the contents of the entire specification, rather than the names of simple terms.

The drawings attached to this specification are for easily explaining the present invention, and the shapes shown in the drawings may be exaggerated as necessary to help understand the present invention, so the present invention is not limited by the drawings.

In the present specification, when it is determined that a detailed description of a known configuration or function related to the present invention may obscure the gist of the present invention, a detailed description thereof will be omitted if necessary.

According to one aspect of the present specification, a thrombus removal device is a strut structure including a first tubular body and a second tubular body disposed inside the first tubular body, wherein one of the first tubular body and the second tubular body comprises: slidable relative to the other, wherein the strut structure is configured to open or close a mouse inviting a thrombus depending on the relative positions of the first tubular body and the second tubular body; a first wire extending from a proximal end to a first distal end, the first proximal end being fixedly connected at a first proximal junction of the proximal end portion of the first tubular body, the first distal end being fixedly connected at a first distal junction with a distal end portion of a first tubular body, wherein when the strut structure is unloaded, the first length is greater than a distance between the first proximal junction and the first distal junction; and a second wire having a second length and extending from a second proximal end to a second distal end, the second proximal end being fixedly connected at a second proximal junction with the proximal end portion of the second tubular body, two distal ends are fixedly connected at a second distal junction with a distal end portion of the second tubular body, wherein when the strut structure is unloaded, the second length is between the second proximal junction and the second distal junction greater than a distance of - wherein the first wire limits a distance between the first proximal junction and the first distal junction of the first tubular body to within the first length, and wherein the second wire comprises the second wire limiting the distance between the second proximal junction and the second distal junction of two tubular bodies within the second length, whereby the first wire and the second wire reduce the cross-sectional area of the strut structure and the strut structure Avoid excessive stretching of the strut structure causing separation of the thrombus engaged in it. In addition, the first wire may be mounted on the circumferential surface of the first tubular body, and the second wire may be mounted on the circumferential surface of the second tubular body. In addition, when the deformation of the strut structure is limited through the first wire and the second wire, the first wire is located in a first radial direction with respect to the central axis of the strut structure, and the second wire is the strut structure may be located in a second radial direction with respect to the central axis of the , and the first radial direction may coincide with the second radial direction. In addition, the first radial direction may be opposite to the second radial direction.

According to another aspect of the present specification, a thrombus removal device is a strut structure comprising a first tubular body and a second tubular body disposed inside the first tubular body, wherein one of the first tubular body and the second tubular body comprises: slidable relative to the other, wherein the strut structure is configured to open or close a mouse inviting a thrombus depending on the relative positions of the first and second tubular bodies; a first wire having a length of one and extending from a first proximal end to a first distal end, the first proximal end being fixedly connected at a first proximal junction with a proximal end portion of the first tubular body; a first distal end is fixedly connected at a first distal junction with a distal end portion of the first tubular body, wherein when the strut structure is unloaded, the first length is between the first proximal junction and the first distal junction greater than a distance between - and a second wire having a second length and extending from a second proximal end to a second distal end, the second proximal end being fixed at a second proximal junction with the proximal end portion of the second tubular body wherein the second distal end is fixedly connected with the distal end portion of the second tubular body at a second distal junction, wherein when the strut structure is unloaded, the second length is equal to the second proximal junction and greater than the distance between the second distal junction, wherein the ratio of the length of the first tubular body to the second tubular body is between the first proximal junction of the first tubular body and the first distal junction constant by the second wire limiting the distance between the second proximal junction and the second distal junction of the first wire and the second tubular body within the first length to within the first length is kept

According to another aspect of the present specification, a thrombus removal device includes a first segment, a second segment distal to the first segment, and connecting the first segment and the second segment, the first segment and the second segment a strut structure comprising a first bridge extending along a first imaginary line parallel to the longitudinal axis of the two segments and a first wire extending from a proximal end to a distal end having a first length, the proximal of the first wire a distal end of the first wire is fixedly connected at a first point with the first segment, and a distal end of the first wire is fixedly connected with the second segment at a second point, and the strut structure is not stretched along the axis; wherein the first length is greater than the distance between the first point and the second point, the first wire comprising the distance between the first point and the second point of the strut structure as the first length wherein the first point is located proximal to the first bridge along the first imaginary line, and the second point is located distally of the first bridge along the first imaginary line, through which the The first wire is disposed alongside the first bridge when the strut structure is stretched along the axis. Further, the first point may be located at a proximal portion of the first segment and the second point may be located at a distal portion of the second segment. In addition, the strut structure includes a third segment located distally of the second segment and a third segment connecting the second segment and the third segment and parallel to the longitudinal axis of the second segment and the third segment. 2 , further comprising a second bridge extending along an imaginary line, wherein the thrombus removal device has a second length and extends from a proximal end to a distal end, the proximal end of the second wire and the second segment fixedly connected at a third point, wherein the distal end of the second wire is fixedly connected with the third segment and at a fourth point, wherein when the strut structure is not stretched along the axis, the second length is greater than the distance between the three points and the fourth point, wherein the second wire limits the distance between the third point and the fourth point of the strut structure to within the second length; 3 points are located proximal to the second bridge along the second imaginary line, and the fourth point is located distally of the second bridge along the second imaginary line, through which the strut structure is positioned along the axis. When stretched, the second wire may be disposed along the second bridge. Also, the second point of the second segment may be located more proximal than the third point of the second segment. In addition, the first virtual line and the second virtual line are located on the circumferential surface of the strut structure, and the rotation angle from the first virtual line to the second virtual line with respect to the central axis of the strut structure is approximately 90 It can also be

According to another aspect of the present specification, a strut structure comprising a first segment, a second segment distal to the first segment, and a bridge connecting the first segment and the second segment, the strut structure having a first length; a first wire extending from a proximal end to a distal end, the proximal end of the first wire being fixedly connected at a first proximal junction with the proximal portion of the first segment, the distal end of the first wire being the distal end of the first wire fixedly connected at a first distal junction with a distal portion of a segment, wherein when the strut structure is unloaded, the first length is greater than a distance between the first proximal junction and the first distal junction - and a second length a second wire extending from a proximal end to a distal end with fixedly connected at a second distal junction with the distal portion of the second segment, wherein when the strut structure is unloaded, the second length is greater than a distance between the second proximal junction and the second distal junction; and wherein the first wire limits a distance between the first proximal junction of the first segment and the first distal junction to within the first length, and the second wire limits the distance between the first proximal junction of the first segment and the second proximal junction of the second segment. limiting a distance between the second distal junction and the second distal junction within the second length, whereby the first wire and the second wire cause a reduction in the cross-sectional area of the strut structure and separation of the thrombus engaged with the strut structure A thrombus removal device for preventing excessive stretching of a strut structure is provided. In addition, the first wire may be mounted on the circumferential surface of the first segment, and the second wire may be mounted on the circumferential surface of the second segment. In addition, when the deformation of the strut structure is limited through the first wire and the second wire, the first wire may be parallel to the second wire. In addition, the first wire may be positioned on a straight line with the second wire. In addition, a rotation angle from the first wire to the second wire with respect to the central axis of the strut structure may be approximately 180 degrees.

According to another aspect of the present specification, a strut structure comprising a first segment, a second segment distal to the first segment, and a bridge connecting the first segment and the second segment, the strut structure having a first length; a first wire extending from a proximal end to a distal end, the proximal end of the first wire being fixedly connected at a first proximal junction with the proximal portion of the first segment, the distal end of the first wire being the distal end of the first wire fixedly connected at a first distal junction with a distal portion of a segment, wherein when the strut structure is unloaded, the first length is greater than a distance between the first proximal junction and the first distal junction - and a second length a second wire extending from a proximal end to a distal end with fixedly connected at a second distal junction with the distal portion of the second segment, wherein when the strut structure is unloaded, the second length is greater than a distance between the second proximal junction and the second distal junction; and wherein the ratio of the length of the first segment to the second segment comprises: the first wire and the first wire limiting the distance between the first proximal junction and the first distal junction of the first segment within the first length and a thrombus removal device held constant by the second wire limiting a distance between the second proximal junction and the second distal junction of a second segment within the second length.

According to another aspect of the present specification, a strut structure including a plurality of cells having a predetermined boundary shape including two length ends and two circumferential ends and connected to the strut structure, the strut structure is recovered from the blood vessel of the patient A thrombus removal device comprising a pull wire configured to be subjected to an extracting, retrieving operation, the pull wire configured to be manipulated to move the strut structure along a longitudinal direction of the strut structure, wherein the plurality of cells are located at the boundary a corresponding first strut element, wherein some of the plurality of cells extend linearly from one of the two length ends to the other of the two length ends, and define an interior area defined by the boundary. further comprising a second strut element transverse to the longitudinal direction of the strut structure, wherein the second strut element prevents an increase in length of some of the plurality of cells, wherein the increase in length increases the length of the strut structure Occurs in the remainder of the plurality of cells without the second strut element due to movement in the longitudinal direction, whereby some of the plurality of cells reduce the change in length of the strut structure during the recovery process A thrombus removal device is provided. In addition, some of the plurality of cells may include a first cell and a second cell, and the first cell and the second cell may be located in different radial directions with respect to a longitudinal central axis of the strut structure. . In addition, a second strut element of the first cell and the second cell may overlap in a longitudinal direction of the strut structure. In addition, the first cell and the second cell may be sequentially positioned along the longitudinal direction of the strut structure. In addition, the first cell and the second cell may be spaced apart along the longitudinal direction of the strut structure. In addition, some of the plurality of cells include a first cell, a second cell, and a third cell sequentially positioned along the longitudinal direction of the strut structure, and the first cell and the second cell are the length of the strut structure. The angle with respect to the central axis of the direction may be substantially the same as the angle of the second cell and the third cell with respect to the central axis of the longitudinal direction of the strut structure.

According to another aspect of the present specification, a plurality of cells comprising a first cell and a second cell, wherein the first cell and the second cell have a predetermined shape including two lengthwise ends and two circumferential ends. a strut structure connected to the strut structure and configured to receive an operation for extracting, retrieving the strut structure from a blood vessel of a patient, wherein the operation is performed to move the strut structure along a longitudinal direction of the strut structure In the thrombus removal device comprising a pull wire configured to a first strut configuration and at least one second strut configuration extending linearly from one of the two longitudinal ends to the other of the two longitudinal ends and longitudinally traversing the interior area defined by the boundary; wherein when the strut structure is moved proximally, the first cell deforms differently from the predetermined shape while the at least one second strut configuration maintains the second cell in the predetermined shape, thereby Due to this, the second cell provides a thrombus removal device that reduces the length change of the strut structure during the recovery process.

According to another aspect of the present specification, a structure including a first strut forming a plurality of cells including a first cell and a second cell having the same shape under a no-load condition and a first strut is disposed in the second cell, the first joint an anti-stretching structure comprising a second strut extending between a joint and a second joint, wherein the first joint is located on the first strut and is located in a proximal portion of the second cell; and a joint is positioned on the first strut and positioned at a distal portion of the second cell, wherein the anti-stretching structure is configured such that, during longitudinal movement of the structure, in the no-load condition, the anti-stretch structure is preventing an increase in the length of the second cell by the second strut having a length substantially equal to the distance between the first joint and the second joint, whereby the second cell causes a thrombus preventing excessive stretching of the structure A removal device is provided. In addition, the second strut may extend along a straight line having an angle smaller than a predetermined value with respect to the longitudinal axis of the structure. One of the first cell and the other of the first cell may face each other with respect to a central axis in the longitudinal direction of the structure. One of the first cells and the other of the first cells may not be adjacent to each other.

According to another aspect of the present specification, a structure comprising a plurality of rows, each of the plurality of rows being connected to a structure including a plurality of cells and the structure, is manipulated to move the structure in a blood vessel of a patient. configured pull wire; In a thrombus removal device comprising , the second cell includes a first strut forming a boundary of the second cell, wherein the first cell includes the first strut forming a boundary of the first cell and a longitudinal direction at the boundary of the first cell and a second strut extending to and traversing an interior region of a boundary of the first cell, the second strut maintaining the length of the first cell of each of the plurality of rows during longitudinal movement of the structure; And, thereby, the first cell provides a thrombus removal device that prevents excessive stretching of the structure.

The present specification relates to a thrombus removal device and a thrombus removal method using the same.

The thrombus removal device is a device used for the treatment of vascular diseases, and the thrombus removal device may remove the blood vessel from the blood vessel in a mechanical manner.

In general, a thrombus removal device is used to remove a thrombus from a blood vessel in order to restore the flow of blood that is blocked or reduced due to a thrombus adhering to the blood vessel wall, and is mainly used for the treatment of cerebrovascular diseases such as ischemic stroke.

A clot removal device is often called a stent retriever because it has a structural feature similar to that of a conventional stent inserted into the body to prevent blood vessel occlusion or vascular stenosis. It is also called a mechanical thrombectomy device).

The process of removing a thrombus using a thrombus removal device may be described as follows.

First, a location where blood flow is blocked in a user's blood vessel is detected, and then the guide wire is moved to the corresponding location. When the guide wire is positioned in the vicinity of the thrombus, the catheter is moved to the vicinity of the thrombus under the guidance of the guide wire. Once the catheter is properly positioned, a stent retriever, that is, a blood clot removal device, is inserted into the body using the catheter in earnest. Here, the thrombus removal device may move to the vicinity of the thrombus along the inside of the tube-shaped catheter in a collapsed configuration. When the thrombus removal device reaches the vicinity of the thrombus, the thrombus removal device is held in place and the catheter is withdrawn to release the thrombus removal device from the catheter. As will be described later, since the thrombus removal device is manufactured using a highly elastic material such as nitinol or a nitinol-based memory shape alloy, the thrombus removal device from the catheter expands and changes its shape to a deployed configuration. , during this expansion process, it engages with a thrombus located in its vicinity. After the thrombus removal device is sufficiently well combined with the thrombus, the thrombus is removed from the body together with the thrombus removal device through a pull wire, thereby removing the thrombus and reperfusion.

Hereinafter, a thrombus removal device according to embodiments of the present specification will be described.

As described above, the thrombus removal device is a device used for mechanical thrombectomy, and specifically, a device that holds a thrombus located in a blood vessel to restore blood flow and recovers it from the body. The conventional thrombus removal device has a problem in that shape deformation occurs during the thrombus removal process, and thus the thrombus carried in the thrombus removal device is separated from the thrombus removal device or fragmented. The thrombus removal device according to the embodiment of the present specification has been devised to solve this problem and is a thrombus removal device in which shape deformation is suppressed, and in more detail, an anti-stretching mechanism for suppressing shape deformation of the stent body. It is a thrombus removal device with a mechanism).

Hereinafter, before describing the thrombus removal device according to the embodiments of the present specification, a shape deformation occurring in a conventional thrombus removal device will be described.

1 is a diagram illustrating an example of a shape deformation of a conventional thrombus removal device 10 that occurs during a thrombus removal process.

When the thrombus removal device accommodated inside the catheter in a compressed state is released from the catheter, the thrombus removal device expands in a deployed state. Usually, the stent body is expanded until the cross section of the stent body almost fills the cross section of the blood vessel. During this expansion process, the stent The strut constituting the body digs into the thrombus, and the stent body and the thrombus are combined. When the binding of the stent body to the thrombus is completed, the thrombus removal device coupled with the thrombus is moved to the outside of the body in order to remove the thrombus from the blood vessel.

At this time, the length of the thrombus removal device may be increased as the following forces are applied.

- Transverse force applied to the thrombus removal device in the extracorporeal direction by the pull wire (hereinafter referred to as 'retrieving force')

- Frictional force between the stent body and the vessel wall caused by radial force (hereinafter referred to as 'radial force') according to the self-expansion of the stent body, or a thrombus and vessel wall bonded to the stent body The force acting in the opposite direction to the recovery force due to the bonding force between the liver

1 shows that the conventional thrombus removal device 10 increases the length of the stent body 11 during the recovery process from the initial deployed state. In addition, referring to FIG. 1 , it can be seen that the diameter of the stent body 11 decreases as the length of the stent body 11 increases.

Referring back to FIG. 1 , the conventional thrombus removal device 10 may self-expand when released from the catheter to reach an initial deployed state having a first length L1 and a first diameter D1. Here, the first diameter D1 may be similar to the diameter of the blood vessel D1. During the expansion process, the stent body 11 may engage the thrombus. Afterwards, when a pulling force, that is, a recovery force, is applied to the thrombus removal device 10 through the pull wire 12 , a force in the opposite direction to the recovery force acts on the thrombus removal device 10 , and accordingly, the stent The length of the body 11 may increase to become the second length L2 greater than the first length L1 . In addition, since the stent body 11 is provided as an overall flexible and highly elastic strut structure, the diameter of the stent body 11 is reduced to a second diameter D2 smaller than the first diameter D1 due to an increase in length. In addition, the change in length and diameter of the stent body 11 also changes the shape of the cell 13 formed by the struts constituting the stent body 11 .

Changes in the length, diameter, and cell shape of the stent body may cause separation or fragmentation of the thrombus coupled to the stent body 11 . For example, when the diameter of the stent body 11 decreases, a gap may occur between the stent body 11 and the blood vessel wall as shown in FIG. 11) can be deviated from. For another example, the cell 13 of the stent body 11 is usually designed to have an optimal shape for clot engagement. It may be detached from the stent body 11 . As another example, during the process of changing the shape of the cell 13 , the struts constituting the cell 13 may break the thrombus and fragmentation of the thrombus may occur.

Therefore, the conventional thrombus removal device 10 may change in shape during the thrombus recovery process as shown in FIG. 1 , which may lead to separation and fragmentation of the thrombus, which may result in failure to restore blood flow. will be.

2 is a view of another example of a shape deformation of the conventional thrombus removal device 10 that occurs in the thrombus removal process, and FIG. 3 is a diagram related to the thrombus fragmentation occurring in the conventional thrombus removal device 10, FIG. 4 is a view related to thrombus separation occurring in the conventional thrombus removal device 10 .

Cerebral blood vessels, which are mainly used for thrombus removal devices, typically include many sharp curve sections, and their diameters are generally not constant, ranging from about 1 mm to 5 mm for each location. Therefore, a relatively high pressure may be concentrated on a specific part of the stent body due to a change in the curve or diameter of the blood vessel wall during the recovery process of the thrombus removal device, and accordingly, as shown in FIG. 2 , the conventional thrombus removal device 10 ) of the stent body 11 may be wholly or partially deformed.

For example, based on the curve section of the stent body 11 of the conventional thrombus removal device 10 passing through the curve section, the curve section spanning the curve section, the proximal section and the curve positioned in the extracorporeal direction rather than the curve section If we look at the distal portion located on the opposite side of the body than the section, a relatively high pressure is applied in the curve section, so a relatively small lateral force is applied to the distal section and a relatively high lateral force is applied to the curved section and the proximal section. and, accordingly, the shape of each part may be differently deformed.

3 shows a relatively small deformation occurs in the distal portion of the stent body 11 of the conventional thrombus removal device 10, but a relatively large deformation occurs in the curved portion, and thus the stent body 11 captures the thrombus. It shows that the thrombus is fragmented by receiving a high compressive force in the process of passing through this curve section.

4 shows a relatively small deformation occurs in the distal portion of the stent body 11 of the conventional thrombus removal device 10, but a relatively large deformation occurs in the curved portion, and thus the stent body 11 captures the thrombus. It shows that the thrombus is separated from the stent body 11 in the process of passing through this curve section.

As described above, the shape of the conventional thrombus removal device may be changed during the recovery process, etc., which may cause thrombus separation or fragmentation, which may act as a factor for lowering the reperfusion rate as a result.

The thrombus removal device according to the embodiments of the present specification may include an anti-stretch mechanism for preventing the above-described shape deformation so that shape deformation may be suppressed.

Here, the anti-stretching mechanism is a configuration that suppresses deformation of the thrombus removal device, particularly the stent body, and may be a structure that prevents or limits the length deformation of the stent body. Specifically, the anti-stretching mechanism may prevent or limit the increase in the length of the stent body due to a lateral force acting on the stent body (force acting in the longitudinal direction of the stent body according to the force in the opposite direction to the recovery force). In addition, the anti-stretch mechanism can prevent or limit the change in diameter or deformation of the cell by inhibiting the increase in the length of the stent body.

In the present specification, the anti-stretching mechanism may be provided in various forms. According to an example, the anti-stretching mechanism may be provided in the form of a wire (hereinafter referred to as an 'anti-stretching wire') fixed to two points of the thrombus removal device. According to another example, the anti-stretching mechanism may be provided in the form of a strut crossing the inside of a cell of the stent body (hereinafter referred to as an 'anti-stretching strut') or in the form of a cell including such a strut (hereinafter referred to as an anti-stretching cell). can In addition to this, the anti-stretching mechanism should be interpreted as including various structures and shapes that limit excessive deformation of the stent body by external forces.

As described above, the thrombus removal device according to the embodiments of the present specification is a device used for mechanical thrombus removal for reperfusion of blood vessels, and excessive shape deformation during thrombus removal can be suppressed.

The thrombus removal device according to the present specification may include a stent body, a pull wire, and the anti-stretch mechanism described above. Here, the stent body is a component directly carrying the thrombus, the pull wire is a configuration that applies a recovery force to the stent body, and the anti-stretching mechanism is a configuration that suppresses excessive shape deformation of the stent body.

Hereinafter, components of the thrombus removal device according to the embodiments of the present specification will be described.

In the thrombus removal device according to the embodiments of the present specification, the stent body is accommodated in the catheter in a compressed state, and the catheter is released from the catheter after reaching the procedure point, that is, the point where the thrombus is located in the blood vessel, and then expands to the deployed state. and carrying a thrombus during or after the expansion process, the pull wire retrieves the stent body with the thrombus out of the body together with the thrombus, and the anti-stretching mechanism prevents excessive deformation in the deployed state, thereby suppressing excessive shape deformation. Mechanical thrombectomy can be performed with a high reperfusion rate.

The stent body may be provided as a highly elastic mesh framework capable of shape deformation.

The stent body is placed in a catheter from outside the body, moves through the blood vessel to the point of operation, and then leaves the catheter and binds to or captures a thrombus. Therefore, it needs to be deformed. Therefore, the stent body is a highly elastic structure that can be transformed into a deployed configuration suitable for carrying a thrombus by self-expansion when it is released from the catheter from the collapsed configuration compressed to be placed in the catheter. is provided

To this end, the stent body may be provided as a mesh-based structure formed by struts made of a highly elastic material. Here, the strut has a linear structure, and a material of high elasticity including nitinol or a memory shape alloy based on nitinol may be mainly used as the material. The stent body may be manufactured to have a tube-shaped mesh structure with an empty interior using struts made of such a high elasticity material. Here, the strut may form the stent body by forming the rim of the cell constituting the mesh structure. The stent body provided as a mesh-based structure made of high elastic material is compressible/expandable, so it can be inserted into the catheter in a compressed state, and when it comes out of the catheter, it self-expands to reach a deployed state.

More specifically, looking at the stent body, the stent body may be manufactured by first forming a shape in a deployed state with a strut made of a material such as nitinol, and then heating it at a high temperature to memorize the shape in the deployed state. The stent body manufactured in this way is made of a high-elastic material, so it is easy to compress, and when the external force is removed in the compressed state, it has the property of restoring to the shape remembered at high temperature.

On the other hand, in the present specification, the strut is used as a term in terms of elements constituting the stent body, and should be interpreted as not meaning the number of physical strands. In addition, the number of physical strands of the strut will be expressed using the term "strand". Illustratively, if the cell constituting the mesh structure of the stent body in the present specification is in the form of a diamond having four edges, the cell may be expressed as consisting of four struts regardless of whether it is actually formed of one strand or multiple strands. have. Also exemplarily in the present specification, even if the stent body has a mesh structure having a plurality of cells, the entire stent body is made through a manufacturing technique of bottom-up by twisting a single strand of wire. may be expressed as a single-strand structure. However, the distinction between the strut and the strand is not necessarily clear, and for the convenience of description, it should be noted in advance that they may be used interchangeably within the range apparent to those skilled in the art.

In addition, the stent body may optionally include a structure for introducing a thrombus into the stent body, that is, a clot inviting structure.

Thrombus is clinically divided into soft clot and hard clot depending on its hardness. In general, vascular occlusion or vascular stenosis occurs when embolus in the blood aggregates to form a clot, which gradually hardens over time and grows from a brittle thrombus to a menstrual thrombus. In the case of a thrombus, the strut can penetrate into the thrombus relatively easily during the self-expansion process of the stent body, so it is highly likely to be combined with the stent body. There is a possibility that only deforms the shape of the stent body and does not combine with the stent body. In this case, the menstrual thrombus may partially distort the shape of the stent body.

The thrombus primary structure may be understood as a configuration for increasing the vascular reperfusion rate for vascular occlusion due to the menstrual thrombus, which is not easily coupled to the above-described stent body. The thrombus primary structure may be provided in various forms, and some examples thereof will be described below.

For example, the stent body may have an opening through which a thrombus can pass in a direction (hereinafter, referred to as a 'proximal direction') toward the outside of the body in the longitudinal direction of the stent body.

As another example, some of the cells constituting the outer surface of the stent body may be provided larger than other cells so that the thrombus is received through the cells into the stent body. Specifically, the stent body may have a cell (hereinafter, referred to as an 'enlarged cell') formed in a size large enough to serve as a passage for the thrombus located on the outside of the stent body to move into the entire interior of the stent body. have.

For another example, the stent body may be provided in a multi-segment form formed by connecting a plurality of segments having a single mesh structure, and may be provided in a structure having a gap formed between the segments. have.

Meanwhile, in the above, the thrombus has been described by dividing it into a menstrual thrombus and a soft thrombus, but it should be noted in advance that this is only for convenience of explanation of the primary structure of the thrombus. Physically, thrombus is not divided into brittle thrombus and menstrual thrombus based on a specific hardness value, and in relation to the description of thrombus binding and thrombus capture, which will be described later, thrombus binding must be performed only for brittle thrombus, and thrombus capture is not possible. It is not necessarily made only for menstrual thrombi, and even in the case of brittle thrombi, it can be accommodated in the stent body through the thrombus primary structure.

The stent body can carry blood clots. Specifically, the stent body may bind to or capture a thrombus using a mesh structure or a clot inviting structure, and accordingly, the thrombus removal device may carry the thrombus.

For example, the stent body may combine with the thrombus through a strut constituting the stent body digs into a thrombus located nearby in the process of self-expanding at the operation point. In another example, the stent body may capture the thrombus by receiving the thrombus located outside the stent body into the interior of the stent body through the thrombus primary structure described above.

Hereinafter, when the strut penetrates into the thrombus and the thrombus is coupled to the stent body, it will be referred to as 'clot engagement', and the thrombus being accommodated into the stent body will be referred to as 'clot capturing'. do. In addition, the state in which the thrombus binding or thrombus capture is performed by the stent body will be expressed as holding the thrombus by the thrombus removal device.

The pull wire may transmit a lateral force to the stent body.

One end of the pull wire may be directly or indirectly connected to the stent body and the other end may be directly or indirectly connected to a user or robotic surgical device performing thrombus removal. The pull wire may receive a pulling force or a pushing force from a user or a robotic surgical device through the other end, and may transmit the force to the stent body through one end.

In general, the transverse force may be primarily a recovery force, but this is not necessarily the case. For example, in the push-and-pluff technique, which is one of the techniques for strengthening the bond between the thrombus and the stent body, the pull wire applies some force to the stent body in the opposite direction to the recovery force. can also be forwarded to

The anti-stretch mechanism can prevent excessive deformation of the stent body.

Here, the anti-stretch mechanism is to prevent the stent body from being deformed by an external force such as a recovery force through a pull wire in a state in which the stent body is already deployed, including the recovery process of the stent body, and the stent body is deployed in a compressed state It should be pointed out in advance that it is not intended to prevent self-deformation that occurs in the process of self-expanding to a state.

On the other hand, in the description related to the anti-stretching mechanism to be described later, the anti-stretching mechanism may fundamentally prevent the deformation of the stent body. It will be referred to as preventing 'excessive deformation' in a comprehensive manner with respect to the limitation of deformation for the above.

Therefore, excessive deformation means a change in the shape of the stent body to such an extent that thrombus separation or thrombus fragmentation occurs in the thrombus removal device, and specific examples or values corresponding to excessive deformation will be described separately later.

Hereinafter, a thrombus removal device according to embodiments of the present specification will be described. The thrombus removal device described below may use an anti-stretching mechanism in the form of an anti-stretching wire.

Here, the anti-stretch wire may be provided as a wire having a predetermined length attached to at least two points of the thrombus removal device. The anti-stretch wire may fix the distance between two points of the thrombus removal device or prevent the distance between the two points from increasing more than a certain amount, thereby preventing excessive deformation of the stent body. To this end, the anti-stretch wire is provided with a material with relatively low elasticity (for example, nickel-titanium alloy, stainless steel, or a metal or polymer having similar mechanical properties to these), and thus has a characteristic that is strong against length deformation due to external force. may have, but not necessarily. In addition, the anti-stretch wire may be provided as a single-stranded wire as well as a multi-stranded wire if necessary.

On the other hand, the two points where the anti-stretching wire is connected to the thrombus removal device may be mainly arranged in a direction parallel to or close to the longitudinal direction of the stent body, and accordingly, the anti-stretching wire is mainly located on the stent body in the longitudinal direction. By applying the tension, the length deformation of the stent body can be restrained (restrain), and diameter deformation and cell shape deformation can be suppressed based on the inhibition of the length deformation.

Hereinafter, examples of the thrombus removal device according to the present embodiment having an anti-stretching mechanism in the form of an anti-stretching wire will be described.

5 is a diagram illustrating an example of a thrombus removal device according to an embodiment of the present specification, and FIG. 6 is a diagram illustrating an operation of the thrombus removal device according to FIG. 5 .

Referring to FIG. 5 , the thrombus removal device 1000 according to the present example includes a stent body 1100 , a pull wire 1300 , and an anti-stretch wire 1500 .

5, the stent body 1100 is provided as a mesh structure in which cells are disposed on the outer surface of the hollow formed by the strut, and binds to the thrombus through the mesh structure or captures the thrombus therein. can

A mesh structure may be formed including a plurality of cells 1103 formed by struts 1101 . Specifically, the strut forms the rim of the cell 1103 , the cell 1103 may be formed by the strut 1101 constituting the rim, and the strut 1101 forms a plurality of cells 1103 , thereby forming a stent An overall mesh structure of the body 1100 may be formed. In FIG. 5 , the cell 1103 is shown as having a diamond shape, but the size or shape of the cell 1103 is determined by the degree to which it is combined with the thrombus, the radiation force of the stent body 1100, the flexibility of the thrombus removal device 1000, and the like. It may have an impact, so it can be appropriately designed considering these factors. Also, the shape or size between the individual cells 1103 does not necessarily have to be the same. In addition, some cells 1103 may be provided in the form of the above-described expanded cell for inviting a thrombus.

The above-described mesh structure of the stent body 1100 may be manufactured through various manufacturing methods, an example of the manufacturing method is laser cutting, micro machining, electrical discharge machining (EDM, electrical discharge machining). , braiding, etc., and other examples include mechanical locks, welding, soldering, brazing, and adhesive molding. ), a method of connecting the struts through crimping, and the like. Here, the mechanical engagement may include, but is not limited to, twisting, knitting, webbing, mesh, or intertwining. Meanwhile, since the stent body 1100 is finally completed as a mesh structure using struts, the stent body 1100 may be referred to as a strut framework. Here, the strut structure should be interpreted in advance as a comprehensive term that includes both the stent body 1100 of the form manufactured from the strut of the metal wire form, as well as the stent body 1100 of the form made by cutting a metal tube. .

Meanwhile, the stent body 1100 may include a material for securing visibility of the thrombus removal device 1000 during the thrombus removal process. In general, since mechanical thrombus removal is performed in the body, it is impossible for the user to visually check the position, operation, or shape of the thrombus removal device 1000 , and visibility can be improved using X-rays or similar see-through light. Efforts are being made to secure it. In the present specification, the stent body 1100 may be made of a material including platinum, a platinum iridium alloy, or another material having high visibility under fluoroscopy to provide visual feedback to the user, and these visible materials are the stent body 1100 of the stent body 1100 . Visibility may be secured by a form coated on the surface, a form inserted into the strut 1101, a form in which an object such as a marker providing visibility is attached to the stent body 1101, or a combination thereof.

Referring back to FIG. 5 , the stent body 1100 may have a proximal end positioned on the pull wire 1100B side and a distal end positioned on the opposite side. Here, in the stent body 1100, a portion close to the proximal end is a proximal portion, a portion close to the distal end is a distal portion, and a portion located between the proximal portion and the distal portion may be a body portion. have.

The proximal portion of the stent body 1100 is a portion where the progress of the struts constituting the stent body 1100 is started, and may be a portion that receives a force such as a recovery force from the pull wire 1300 .

More specifically, the struts 1101 may be gathered at a point at the proximal end, and at the proximal end in the distal direction, that is, in the direction away from the pull wire 1300 in the longitudinal direction of the stent body 1100, at a point at the proximal end. As the gathered struts 1101 spread, the diameter of the stent body 1100 may gradually increase. In addition, the pull wire 1300 may be directly or indirectly connected to the proximal end or one point of the proximal portion, through which the proximal portion transmits a force for movement or manipulation of the stent body 1100 from the pull wire 1300 can receive

The body portion of the stent body 1100 is a portion extending from the proximal portion, and may be a portion substantially carrying a thrombus.

More specifically, the body may have a hollow tube shape, and an outer surface thereof may have a mesh structure including cells formed by struts. The body portion may be combined with the thrombus through such a mesh structure, and may trap the thrombus in its internal space. Although the body part is illustrated in a simple hollow cylinder shape in FIG. 5, the body part may be implemented in various other shapes. For example, although FIG. 5 shows that the diameter of the body is constant over the entire body, it is also possible that the diameter of the body is different at other points in the longitudinal direction. For another example, although FIG. 5 shows the body in a single segment type, the body may be of a multi-segment type having a plurality of segments. Since the description of the multi-segment stent body 1100 will be described later, a detailed description thereof will be omitted.

The distal portion of the stent body 1100 is a portion extending from the body portion. The distal portion may simply form the distal end of the stent body, but may serve to ultimately prevent the thrombus from dislodging from the distal end of the stent body 1100 in the process of recovering the stent body 1100 .

As an example, the distal portion may be provided in a closed end type as shown in FIG. 5 . In the closed distal portion, the struts 1101 are gathered in the distal direction as shown in FIG. 5 to reduce the diameter of the stent body 1100 . At this time, the struts 1101 may converge at a point at the distal end of the distal portion. However, the struts 1101 may not necessarily converge at the distal end and may not necessarily have to gradually decrease in diameter from the distal portion to the distal direction.

The closed distal part prevents the separation or leakage of a thrombus or fragmented thrombus carried by the thrombus removal device 1000 at the last end of the stent body 1100 in the process of the thrombus removal device 1000 being recovered, or is separated or leaked. It can re-engage with blood clots.

As another example, although FIG. 5 shows the distal portion in a closed configuration, the distal portion may alternatively be of an open end type. Depending on the point of view, the open distal portion may be interpreted as a part of the body portion. Since the open distal portion minimizes the influence of the stent body 1100 on the flow of blood, the stent body 1100 can be moved quickly during the recovery process. In addition, the stent body 1100 having an open distal portion has a relatively easy shape deformation compared to the stent body 1100 having a closed distal portion, so it is somewhat advantageous to pass a curved section or a narrow diameter section of a blood vessel. The open distal portion may also be provided in a form of gradually decreasing diameter, such as the closed distal portion.

Referring back to FIG. 5 , the pull wire 1300 may receive a force for operating the thrombus removal device 1000 from a user or a surgical robot, and may transmit it to the stent body. To this end, the pull wire 1300 is made of a material having high tensile strength and can perform instructions transmitted from outside the body, and the material of the pull wire 1300 is mainly nickel-titanium alloy or stainless steel. However, the present invention is not limited thereto.

The pull wire 1300 may receive force from a user or a surgical robot through one end or a portion close to one end thereof. For this purpose, it is common that a portion of the pull wire 1300 extends outside the body, but the pull wire 1300 does not necessarily have to directly contact the user or the surgical robot, and indirectly the driving unit of the user or the surgical robot as necessary. Since it is also possible to be connected to the back, a portion of the pull wire 1300 does not necessarily have to extend to the outside of the body.

In addition, the pull wire 1300 may transmit the force to the stent body 1100 through the other end or a portion close to the other end. To this end, one portion of the pull wire 1300 may be directly or indirectly connected to the stent body 1100 .

For example, the pull wire 1300 may be connected to the proximal end of the stent body 1100 as shown in FIG. However, the pull wire 1300 does not necessarily have to be directly attached to the proximal end, and is connected to the stent body 1100 through another medium in the middle or connected to the stent body 1100 through a site other than the proximal end. It is also possible

On the other hand, Figure 5 shows that the pull wire 1300 is connected with the proximal end on the central axis extending in the longitudinal direction of the stent body 1100 along the center of the cross section of the stent body 1100, but this is the stent body ( 1100), it is obvious that it can be appropriately deformed according to the shape of the proximal part. Various modifications to the connection relationship between the stent body 1100 and the pull wire 1300 can be fully understood by those skilled in the art through the examples described through the various drawings attached to this specification, so a detailed description thereof will be omitted.

A user or a surgical robot can operate the thrombus removal device through the pull wire 1300 .

For example, the stent body 1100 may be moved in the blood vessel according to the manipulation of the pull wire 1300 . Specifically, by pulling the pull wire 1300 , a recovery force is applied to the stent body 1100 , and through this, the thrombus removal device 1000 carrying the thrombus can be recovered outside the body. In addition, the push-and-fluff technique described above may also be performed through manipulation of the pull wire.

The anti-stretch wire 1500 may prevent excessive deformation of the stent body 1100 . Specifically, the anti-stretch wire 1500 is attached to at least two points of the thrombus removal device 1000 , and by limiting the distance between the two points to a predetermined length or less, length deformation of the thrombus removal device 1000 may be suppressed. When the length deformation of the thrombus removal device 1000 is suppressed, the diameter deformation of the thrombus removal device 1000 or the deformation of the cell 1103 can also be suppressed, as a result, the anti-stretching wire 1500 is the thrombus removal device 1000 . Excessive deformation can be suppressed.

5, the anti-stretch wire 1500 may be fixed to the proximal end and the distal end of the stent body 1100, both ends of which are respectively disposed on the central axis of the stent body 1100, no load without external force It may have the same length as the overall length of the stent body 1100 in the deployed state under the condition.

The anti-stretch wire 1500 of the thrombus removal device 1000 illustrated in FIG. 5 described above may prevent an increase in the length of the stent body.

Specifically, referring to FIG. 6 , for example, after the stent body 1100 is deployed in a blood vessel, a lateral force applied to the stent body 1100 in the process of recovering the thrombus removal device through the pull wire 1300 . may induce an increase in the length of the stent body 1100 . At this time, the anti-stretch wire 1500, which is robust to deformation, has both ends fixed to the proximal end and the distal end of the stent body 1100, and the distance between both ends of the stent body 1100 is the length of the anti-stretch wire 1500, That is, it is possible to counteract the increase in length beyond the length of the stent body 1100 in the deployed state under the no-load condition. Accordingly, the anti-stretch wire 1500 can prevent a change in the length of the stent body 1100 .

In the above, it is coupled with the stent body 1100 through both ends of the stent body 1100 provided in the form of FIG. The total length of the stent body 1100 has been described with respect to the anti-stretch wire 1500 to prevent an increase of more than the total length of the anti-stretch wire 1500 .

However, the anti-stretching wire 1500 described with reference to FIG. 5 is only one of the most basic types of the anti-stretching wire 1500 disclosed herein, and the anti-stretching wire 1500 disclosed herein is a thrombus removal Various examples for preventing excessive deformation of the stent body 1100 when an external force is applied to the device 1000 may be encompassed, and this may be implemented through various design changes.

Hereinafter, some aspects related to the design of the anti-stretch wire will be described.

The anti-stretch wire 1500 may include a connection portion 1502 connected to the thrombus removal device 1000 and an extending portion 1504 extending between the connection portion.

The connecting portion 1502 may be an end of the anti-stretching wire 1500, as in the example shown in FIG. 5, but it is not necessarily the case, and any point of the anti-stretching wire 1500 may be used. Hereinafter, a connection portion 1502 positioned in a relatively proximal direction of the thrombus removal device among two connection portions 1502 adjacent to each other is a frontal connection portion, and a connection portion located in a relatively distal direction is a rear connection portion ( rear connection portion).

Also, the connection part 1502 with the thrombus removal device does not necessarily have to be a point contact type. For example, the anti-stretch wire may be connected through a line contact with a predetermined section of the strut 1101 of the stent body 1100 .

In addition, the anti-stretch wire may have at least two or more connecting portions 1502 . In the example shown in FIG. 5 , the anti-stretching wire 1500 is illustrated as being connected to the stent body 1100 at two points, but the number of the connection parts 1502 may be greater than that. For example, the anti-stretch wire 1500 may be connected to the thrombus removal device 1000 at three or four or more sites. The anti-stretching wire 1500 connected to the thrombus removal device 1000 at a plurality of sites may prevent a change in length of the thrombus removal device 1000 between two adjacent connection parts 1502 . As such, when the anti-stretch wire 1500 includes three or more connection parts 1502, the specific connection part 1502 is a rear connection part for the connection part located in the proximal direction than the connection part, and at the same time it is located on the distal direction than the connection part. For the connection part, it may be a potential connection part.

Also, the connection part 1502 of the anti-stretch wire does not necessarily have to be connected to the thrombus removal device 1000 through the distal end of the stent body 1100 . First, the anti-stretch wire 1500 may be connected to the stent body 1100 on any two points of the stent body 1100 . In addition, the anti-stretch wire 1500 may be connected to the thrombus removal device 1000 in another configuration of the thrombus removal device 1000 other than the stent body 1100 . For example, a portion of the connection portion 1502 of the anti-stretch wire 1500 is connected to the pull wire 1300 , and the other portion may be connected to the stent body 1100 . Here, a portion of the thrombus removal device 1000 connected to the anti-stretch wire 1500 may be referred to as a coupling portion. In relation to the coupling portion, the coupling portion connected to the frontal coupling portion will be referred to as a frontal coupling portion, and the coupling portion connected to the rear coupling portion will be referred to as a rear coupling portion. Meanwhile, in the following, terms such as a coupling point, a junction, or a joint may be used interchangeably with respect to the coupling part for convenience of explanation as necessary, and this is understood to refer to the coupling part inclusively. should be

Also, the length of the anti-stretch wire 1500 does not have to be the same as the total length in the deployed state of the stent body 1100 under no-load conditions. For example, when the coupling portion is not at both ends of the stent body 1100, the length of the anti-stretch wire 1500 may be smaller than the overall length. For another example, even if the anti-stretching wire 1500 is combined with the stent body 1100 at both ends of the stent body 1100, to allow some length deformation of the stent body 1100, the anti-stretching wire 1500 is It is also possible to be provided longer than the entire length of the stent body (1100).

The position of the coupling part and the length of the anti-stretching wire 1500 among some aspects related to the design of the above-described anti-stretching wire 1500 are, as mentioned in the description with reference to FIGS. 5 and 6, the anti-stretching wire 1500 ), since the deformation prevention of the stent body 1100 by the anti-stretching wire 1500 is performed in a form that limits the distance between the coupling portions, the anti-stretching effect of the anti-stretching wire 1500 is directly affected. It may be a factor, which will be described in more detail below.

The position of the coupling portion at which the anti-stretching wire 1500 is connected to the thrombus removal device may be determined in consideration of a covering ratio. Here, the covering ratio may mean a ratio of a region (hereinafter referred to as a 'covering region') to which an anti-stretching effect by the anti-stretching wire 1500 is applied among the entire region of the stent body 1100 . Again, as mentioned with reference to FIGS. 5 and 6 , the anti-stretching effect occurs between the point where the anti-stretching wire 1500 and the thrombus removal device 1000 are connected, so the covering area is combined with the coupling part of the stent body 1100 . It may be an area located between the parts. Accordingly, the covering ratio may be specifically defined as the length of the stent body 1100 positioned between the coupling portions for the entire length of the stent body 1100 . In addition, the covering region may be defined as a portion located within the stent body 1100 among the components in the longitudinal direction of the straight stent body 1100 connecting the coupling portion for the entire length of the stent body 1100 and the coupling portion.

For example, in the form in which the anti-stretching wire 1500 is connected to the proximal end and the distal end of the stent body 1100 as shown in FIG. 5 again, the covering area may coincide with the entire area of the stent body 1100 and , thus, the covering ratio may be 100%. This may mean that the anti-stretching effect by the anti-stretching wire 1500 occurs throughout the stent body 1100 .

For another example, from the distal end of the stent body 1100 and the point where the engaging portion is located in the distal direction by 10% of the total length of the stent body 1100 from the proximal end of the stent body 1100 When it is located at a point located in the proximal direction by 10% of the total length, the covering ratio may be 80%. In this case, the length deformation is limited by the anti-stretch wire 1500 in the area from 10% to the front 10% to the rear 10% of the stent body 1100, but in the remaining area, length deformation due to external force may occur without limitation. In the case of the stent body 1100 consisting of a proximal part with a gradually increasing diameter, a body part with a constant diameter, and a distal part with a decreasing diameter, the coupling part is disposed at both ends of the body part (the part connected to the proximal part and the part connected to the distal part) Accordingly, the anti-stretch wire 1500 may limit the deformation of the body portion, but allow deformation of other portions of the stent body 1100. Since the above-described shape of the proximal part and the distal part may be requested to change its shape as necessary during the procedure of mechanical thrombectomy, this request can be satisfied by disposing the coupling part at both ends of the body part.

For another example, the dislocation coupling portion may be located on the proximal direction than the proximal end of the stent body 1100 (eg, one point of the pull wire). When the potential coupling part is located at one point of the pull wire 1300, the covering ratio is the same as when it is located at the proximal end of the stent body 1100, but ease of coupling between the thrombus removal device 1000 and the anti-stretch wire 1500 This can be improved.

On the other hand, as the covering ratio increases, the area receiving the anti-stretching effect in the stent body 1100 increases, and as the covering ratio decreases, the area receiving the anti-stretching effect in the stent body 1100 decreases, so the anti-stretching wire 1500 is In order to prevent excessive deformation of the stent body 1100, the covering ratio needs to be maintained above a certain value. In the present specification, the covering ratio may be preferably 1/2 or more, more preferably 2/3 or more.

On the other hand, in the anti-stretching wire 1500 having the same covering ratio, the anti-stretching effect may vary according to the position of the covering area of the anti-stretching wire 1500 . For example, the closer the covering region to the proximal end than the distal end of the stent body 1100, the greater the anti-stretch effect. This is because the recovery force applied to the stent body 1100 by the pull wire 1300 may act more on the proximal portion than the distal portion of the stent body 1100 . In addition, when the dislocation coupling point to which the front end of the anti-stretch wire 1500 is connected is too far from the proximal end of the stent body 1100, between the proximal end and the dislocation coupling point is not covered by the anti-stretch wire 1500 In the section where it is not possible, excessive length deformation may occur. In consideration of these considerations, preferably, the distance between the proximal end and the proximal end may be smaller than the distance between the proximal end and the distal end.

In addition, the position of the coupling portion where the anti-stretching wire 1500 is connected to the thrombus removal device 1000 may be determined in consideration of an angle formed by a virtual straight line connecting the coupling portion with respect to the longitudinal direction of the stent body 1100 .

Referring back to FIG. 5 , the coupling portions may be disposed along the longitudinal direction of the stent body 1100 . That is, an imaginary straight line connecting the coupling portion may be parallel to the longitudinal direction of the stent body 1100 . This is so that the tension acting on the anti-stretch wire 1500 mainly acts in the longitudinal direction of the stent body 1100 to counteract the lateral force causing the length deformation of the stent body 1100 . However, excessive length deformation of the stent body 1100 by the tension of the anti-stretching wire 1500 can be suppressed even if the virtual straight line connecting the coupling part is arranged at a predetermined angle or less with respect to the longitudinal direction of the stent body 1100. Therefore, the coupling portions are not necessarily arranged in a line along the longitudinal direction of the stent body (1100).

However, if the coupling portion is arranged so that the imaginary straight line connecting the coupling portion has a too large angle with respect to the longitudinal direction of the stent body 1100, among the tension acting on the anti-stretching wire 1500 of the stent body 1100 As the ratio of the force acting in the radial direction of the stent body 1100 to the force acting in the longitudinal direction increases, the anti-stretching efficiency is lowered, and at the same time, an eccentricity is applied to the stent body 1100, so that the stent body 1100 is undesirable. Undesirable behaviors or undesirable shape deformations may occur. Therefore, illustratively in the present specification, the coupling portion may be arranged such that an imaginary straight line connecting the coupling portions is preferably 30 degrees, more preferably 15 degrees or less with respect to the longitudinal direction of the stent body 1100 .

In addition, the anti-stretch wire 1500 may be disposed along a virtual plane extending along the central axis or the surface of the mesh structure at the position of the coupling portion connected to the thrombus removal device 1000 .

Referring back to FIG. 5 , the coupling portions may be disposed along the central axis of the stent body 1100 . However, unlike this, at least some of the coupling parts may be disposed along the surface of the mesh structure constituting the stent body 1100 . Alternatively, at least some of the coupling parts may be located in the pull wire 1300 .

When the coupling portions are arranged along the central axis of the stent body 1100, the tension of the anti-stretching wire 1500 acts in a balanced manner on the stent body 1100, so the length deformation of the stent body 1100 can be stably prevented. there are advantages to

Conversely, when the coupling portions are disposed on a surface extending along the surface of the stent body 1100, the anti-stretch wire 1500 is located on the surface rather than the inside of the mesh structure, so as to the internal space of the stent body 1100. There is an advantage of inviting a thrombus or trapping a thrombus in the internal space.

On the other hand, when the coupling portions are arranged along the surface of the stent body 1100, the pull wire and the stent body 1100 extend along the surface of the stent body 1100 rather than the central axis of the stent body 1100. When connected to each other on the top, the coupling portion preferably extends along the surface of the stent body 1100 so that the recovery force and the tension applied to the stent body 1100 by the pull wire 1300 act on the same line. It may be disposed on the extension direction of the heavy pull wire.

The anti-stretch wire 1500 is provided of an inelastic material, and may have a fixed length that does not substantially elastically deform, and can prevent excessive deformation of the stent body 1100 by using this characteristic.

The length of the anti-stretch wire 1500 may be determined in consideration of a natural distance between coupling portions.

Here, the natural distance may mean a distance on any two points on the stent body 1100 in a deployed state under a condition in which there is no external force. Here, the condition without external force does not necessarily refer only to a state where there is no external force completely, and there is no recovery force to induce length deformation of the stent body 1100, a no-load state, or a catheter. It should be understood as an inclusive term that includes an unrestrained state and the like. It should be noted in this respect that the natural length may also be referred to as an 'undeformed length'. In addition, from a similar point of view, the natural length of the stent body 1100 may refer to the entire length of the stent body 1100 in a deployed state under a condition in which there is no external force.

According to an example, the length of the anti-stretch wire 1500 may be substantially equal to the natural distance between the coupling portions. The anti-stretching wire 1500 having the same length as the natural distance between the coupling portions may prevent length deformation in the covering area of the stent body 1100 . In other words, the anti-stretching wire 1500 may fix the length of the covering region to the lengthwise component value of the stent body 1100 among the distances between the connecting portions of the anti-stretching wire 1500 . Specifically, as shown in Figure 5, the anti-stretch wire can prevent the length deformation of the stent body in the covering area.

According to another example, the length of the anti-stretch wire 1500 may be greater than the natural distance between the coupling portions. The anti-stretch wire 1500 having a length greater than the natural distance between the coupling portions allows length deformation in the covering area of the stent body 1100 to a certain level, but further length deformation can be prevented. Specifically, the anti-stretch wire 1500 is a stent body 1100 from a state in which the distance between the coupling parts is smaller than the length of the anti-stretch wire 1500 to a state in which the distance between the coupling parts is equal to the length of the anti-stretch wire 1500. Allows length deformation of, and when the distance between the coupling portion is equal to the length of the anti-stretching wire 1500 can be prevented from increasing the length of the stent body 1100 beyond that. For example, the anti-stretch wire 1500 that allows the deformation of the stent body 1100 to a certain level is advantageous in the deformation of the stent body 1100 required when the stent body 1100 passes through a curved section of a blood vessel. there may be For another example, when the stent body 1100 is deformed in a compressed state to be inserted into the catheter, the anti-stretching wire 1500 is to allow the length deformation of the stent body 1100 to a certain level. It may be advantageous to minimize the diameter of the body 1100 .

According to another example, the length of the anti-stretch wire 1500 may be smaller than the natural distance between the coupling portions. At this time, since the stent body 1100 is maintained in a slightly smaller state than its natural length, there may be advantages in the radiation force or elastic force of the stent body 1100 .

As mentioned above, the length of the anti-stretch wire 1500 may be determined to be the same as the natural distance, larger than the natural distance, or smaller than the natural distance in consideration of the natural distance between the coupling parts, but if it is too small In the anti-stretching wire 1500 may inhibit the deformation of the stent body 1100 required when passing or compressing the rotation section of the stent body 1100, and if it is too large, the anti-stretching wire 1500 is the stent body 1100. Because it can allow excessive deformation of the, it may be necessary to design the length of the anti-stretching wire 1500 within an appropriate numerical range. Accordingly, the length of the anti-stretch wire 1500 may be preferably between 90% and 150% of the natural distance between the coupling portions, more preferably between 100% and 120%.

In the above, an example of a thrombus removal device having an anti-stretching wire 1500 has been described with reference to FIG. 5 , and then some aspects related to the design of the anti-stretching wire 1500 have been described.

Hereinafter, examples of the thrombus removal device 1000 having various types of anti-stretching wires 1500 based on the above-described disclosure will be described with reference to FIGS. 7 to 35 . However, from the description of the thrombus removal device 1000 disclosed with reference to FIG. 5 in relation to the examples of the thrombus removal device 1000 having the anti-stretch wire 1500 to be described later, detailed information on matters that can be fully understood by those skilled in the art A description will be omitted.

7 is a diagram illustrating another example of the thrombus removal device according to an embodiment of the present specification, and FIG. 8 is a diagram illustrating an operation of the thrombus removal device according to FIG. 7 .

Referring to FIG. 7 , the anti-stretch wire 1500 of the thrombus removal device 1000 according to this example is a single strand connected to the proximal end and the distal end of the stent body 1100 disposed along the central axis of the stent body. provided, the length may be greater than the natural distance between the coupling portions.

Referring to FIG. 8 , the thrombus removal device 1000 may reach a deployed state through self-expansion after being released from the catheter. At this time, the anti-stretch wire 1500 may be hung between the coupling parts in a loose state. Afterwards, when the recovery force is applied through the pull wire 1300, since the anti-stretch wire 1500 is in a loose state, tension does not occur in the anti-stretch wire 1500, and thus the length of the stent body 1100 may increase. . Afterwards, as the length of the stent body 1100 increases, when the distance between the coupling portions reaches the length of the anti-stretching wire 1500, the anti-stretching wire 1500 is in a taut state, and accordingly, the tension of the anti-stretching wire 1500 Due to this, the increase in the length of the stent body 1100 is terminated, and the length of the stent body 1100 may be constantly maintained.

Accordingly, the anti-stretching wire 1500 having a length longer than the distance between the coupling portions as shown in FIG. 7 allows an increase in the length of the stent body 1100 up to a certain level, but prevents an increase in length beyond that, and consequently It is possible to prevent excessive deformation of the stent body 1100 .

9 is a diagram illustrating another example of a thrombus removal device according to an embodiment of the present specification, and FIG. 10 is a diagram illustrating an operation of the thrombus removal device according to FIG. 9 .

Referring to FIG. 9 , the anti-stretch wire 1500 of the thrombus removal device 1000 according to the present example is provided as one strand connecting the coupling portions positioned in a line along the longitudinal direction on the surface of the mesh structure of the stent body. can be In this case, the potential coupling portion of the coupling portion may be located at the proximal end of the body portion of the stent body 1100, the rear coupling portion may be located at the distal end of the stent body 1100, and extending between the two connection portions connected to the stent body in the coupling portion The length of the extended portion may be greater than the natural distance between the two coupling portions.

The extension may be disposed along the inside, outside of the stent body, or a combination thereof. Here, the extension may be disposed inside the stent body 1100 as shown in FIG. 9 . When the extension is located on the inside, the anti-stretch wire 1500 may be relatively free from friction between the stent body 1100 and the blood vessel wall that occurs during the recovery process of the thrombus removal device 1000 .

Meanwhile, unlike shown in FIG. 9 , the extension may be disposed outside the stent body 1100 . In this case, the design may be easier than that the extension is located on the inside of the stent body 1100 . In addition, by passing the anti-stretch wire 1500 in and out of the cell 1103 of the stent body 1100 between the two coupling portions, the extension portion may be alternately positioned inside and outside the stent body 1100. .

Referring to Figure 10, the anti-stretch wire 1500, which is in a loose state in the initial deployed state by the recovery force from the pull wire 1300, may be in a taut state, and at this time, the extension of the anti-stretch wire 1500 is a stent. The cross-section of the body 1100 may be disposed close to the circumferential surface of the stent body 1100 . As such, the extension is not located in the inner space of the stent body 1100, so the anti-stretch wire 1150 may not interfere with the inflow of a thrombus entering the inner space of the stent body 1100, and the stent body 1100 is It can be easy to carry a blood clot in its interior space.

11 is a diagram illustrating another example of the thrombus removal apparatus 1000 according to an embodiment of the present specification, and FIG. 12 is a diagram illustrating an operation of the thrombus removal apparatus 1000 according to FIG. 11 .

In the above description, the stent body 1100 of the form in which the pull wire 1300 is connected on the central axis of the thrombus removal device 1000 has been described as a reference, but the stent body 1100 of the thrombus removal device 1000 is a stent. It may be connected to the pull wire 1300 on the surface side of the mesh structure of the body 1100 .

Referring to FIG. 11 , the anti-stretch wire 1500 of the thrombus removal device 1000 according to this example is on a virtual straight line extending from the pull wire 1300 among virtual surfaces extending from the surface of the mesh structure of the stent body. It may be provided as a single strand connecting the two coupling portions located, and the length thereof may be greater than the natural distance between the two coupling portions. At this time, the two coupling portions may be located at the proximal end (or may be located in the pull wire 1300) and the distal end of the stent body 1100, respectively.

12 , the pull wire 1300 is connected to the stent body 1100 and the anti-stretch wire 1500 is connected to the thrombus removal device 1100. Two coupling portions are substantially on the same straight line. The recovery force acting on the stent body 1100 and the tension of the anti-stretch wire 1500 may act on the same line, and the effect by the anti-stretch wire 1500 is that the tension and the recovery force do not act on the same line. can be improved than the case.

In the above, the distal portion of the stent body of the thrombus removal device may be provided in a closed form or an open form. Among them, when the stent body 1100 having an open distal part is used, the thrombus carried in the thrombus removal device 1000 may be separated from the thrombus removal device 1000 through the open distal terminal. Also, even when a closed distal portion is used, thrombus disengagement may occur depending on the arrangement of the struts at the distal end. A basket 1900 may be optionally provided on the distal side of the stent body 1100 in order to prevent the thrombus from separating.

The basket 1900 is connected to the distal end of the stent body 1100 , and may have a profile that decreases in diameter as it moves away from the distal end of the stent body 1100 . Through this, the basket 1900 may prevent a thrombus entering the interior of the stent body 1100 from escaping or may prevent a thrombus from escaping along the longitudinal direction of the stent body 1100 .

The basket 1900 may be manufactured using a material with high elasticity, such as nitinol or a nitinol-based memory shape alloy, and may include a material having high visibility under fluoroscopy if necessary. The basket 1900 may be separately manufactured through a method such as braiding and then connected to the stent body 1100 , or may be manufactured integrally with the stent body 1100 .

On the other hand, it is common that the proximal end having a wide diameter of the basket 1900 is connected to the distal end of the stent body 1100, but this is not always the case, and in addition to the proximal end of the basket 1900, at a position of the basket 1900 It may be connected to the stent body 1100, and through this, the proximal end of the basket 1900 may have a wider diameter than the diameter of the stent body 1100, and even when the stent body 1100 is not completely in close contact with the blood vessel wall, can be contacted

On the other hand, the thrombus removal device 1100 of the example described above or to be described later through this specification may include a basket 1900, and when the thrombus removal device 1100 includes the basket 1900, an anti-stretch wire ( It is obvious that the coupling portion connected to the 1100 may be located on the basket 1900 .

13 is a view showing one implementation of the thrombus removal device according to an embodiment of the present specification, and FIG. 14 is a view showing an embodiment of the thrombus removal device according to an embodiment of the present specification to be.

The anti-stretch wire 1500 of the thrombus removal device 1000 according to this example connects two coupling parts located on a virtual straight line extending from the pull wire 1300 among the virtual surfaces extending from the surface of the mesh structure of the stent body. It may be provided as a single strand, the length of which may be substantially equal to the natural distance between the two joints. At this time, the front coupling part of the coupling part may be located in the pull wire 1300, the back coupling part in the basket 1900, and the proximal end of the stent body 1100 is extended along a straight line so that it is connected to the back coupling part. The connection portion of the stretching wire 1500 may be formed to extend along the long proximal end of the stent body 1100 to be wide. At this time, the covering ratio of the anti-stretch wire 1500 to the stent body 1100 may be 100%.

The anti-stretch wire 1500 of this example has a covering ratio of 100%, and since it is provided with a length substantially equal to the distance between the frontal coupling part and the backside coupling part, the length of the stent body 1100 is not stretched by an external force and its natural may remain substantially equal to the length.

In addition, the point at which the pull wire 1300 is connected to the stent body 1100 and the front and back coupling portions at which the anti-stretch wire 1500 is connected to the thrombus removal device 1100 are substantially on the same straight line are positioned on the stent body ( The recovery force acting on the 1100 and the tension of the anti-stretching wire 1500 may act on the same line.

In the above description, the thrombus removal device 1000 has been described as including one anti-stretching wire 1500 , but a plurality of anti-stretching wires 1500 of the thrombus removal device 1000 may be used. It may be possible to more stably limit the increase in the length of the stent body 1100 when the thrombus removal device 1000 has a plurality of anti-stretch wires 1500 than when it has only one anti-stretch wire 1500, By using a plurality of anti-stretching wires 1500 symmetrically arranged, it is possible to solve the tension imbalance that occurs when the coupling part is positioned on the surface of the mesh structure as shown in FIG. 9 or FIG. 11 .

The arrangement of the plurality of anti-stretch wires 1500 may vary. The plurality of anti-stretch wires 1500 may be arranged in various combinations defined by a position in a longitudinal direction or a direction in a cross-section of the stent body 1100 of the thrombus removal device 1000 .

As an example, the plurality of anti-stretch wires 1500 may be disposed on different radial directions from the center of the stent body 1100 when viewed from a longitudinal cross-section of the stent body 1100 . In addition, when the plurality of anti-stretch wires 1500 are disposed on different radial directions, their arrangement may be symmetrical to each other. For example, the two anti-stretch wires 1500 may be disposed to face each other about the central axis of the stent body 1100 . For another example, the three anti-stretch wires 1500 may be disposed in a form that forms an angle of 120 degrees with each other from the central axis of the stent body 1100 . For another example, one pair of the four anti-stretch wires 1500 is disposed on the same direction from the central axis of the stent body 1100 and the other pair is on the central axis of the pair and the stent body 1100 . It is also possible to be arranged on the opposite direction.

As another example, the plurality of anti-stretch wires 1500 may be disposed at different positions in the longitudinal direction of the stent body 1100 when viewed from the side of the stent body 1100 . Here, the different positions in the longitudinal direction may be understood that at least some of the positions of the coupling portions of each anti-stretching wire 1500 are different, in other words, that the covering area of each anti-stretching wire 1500 is different from each other. can mean For example, the plurality of anti-stretching wires 1500 have a form in which the covering area partially or entirely overlaps, the start and end of the covering area of the adjacent anti-stretch wire 1500 match, the adjacent anti-stretch wire 1500 of The covering regions may be disposed to be spaced apart from each other or a combination thereof. When the adjacent covering areas overlap, the effect of resisting length deformation may be stronger than when using a single anti-stretching wire 1500 . In addition, in the case where the start and end of the adjacent covering area coincide with the shape, the resistance to length deformation may be similar to the case of using a single anti-stretch wire 1500, but a relatively uniform resistance force over the entire covering area of the stent body 1100 is There may be advantages that arise. In addition, when adjacent covering regions are spaced apart from each other, there may be an effect of increasing flexibility and elasticity of the stent body 1100 as length deformation is allowed between the covering regions.

On the other hand, the arrangement of the plurality of anti-stretch wires 1500 according to the above-described examples may be combined. For example, anti-stretch wires 1500 disposed at different points in the longitudinal direction of the stent body 1100 may be disposed on different directions from the central axis even on a cross-section.

Some examples related to the arrangement of the plurality of anti-stretch wires 1500 will be described with reference to FIGS. 15 and 16 . However, it should be noted in advance that the arrangement of the anti-stretching wire 1500 is not limited to the examples to be described later.

15 is a diagram illustrating an example of a thrombus removal device according to another embodiment of the present specification.

According to this example, the thrombus removal device 1000 may include two anti-stretch wires 1500 having overlapping covering areas with each other, and each anti-stretch wire 1500 is different from the center of the stent body 1100 . It may be disposed in a radial direction. At this time, one of the two anti-stretch wires 1500 may be provided as one strand connecting the two coupling portions located at the proximal end and the distal end of the stent body 1100 , and the other is the proximal end of the body portion. and one strand connecting between the two coupling portions located at the distal end of the stent body 1100, and the length of each anti-stretching wire 1500 may be greater than the natural distance between each of the two coupling portions. .

As shown in Figure 15, when a recovery force is applied from the pull wire 1300, the two anti-stretch wires 1500 can be in a taut state, and by generating tension in the covering area of the stent body 1100, the covering area length increase can be prevented. At this time, by overlapping the two anti-stretching wires 1500 to act on the same covering area, the effect can be increased compared to the case where the single anti-stretching wire 1500 acts, and the two anti-stretching wires 1500 are symmetrical. By being arranged so as to be, the effect can be more uniform than when it is arranged asymmetrically. Here, that the anti-stretching effect is uniformly generated can be interpreted as that the effects on the different radial directions from the center of the stent body 1100 in the longitudinal cross-section are relatively uniform.

16 is a diagram illustrating another example of a thrombus removal device according to another embodiment of the present specification.

According to this example, the thrombus removal device 1000 may include three anti-stretch wires 1500 whose beginnings and ends are coincident with each other, and each anti-stretching wire 1500 is a stent body 1100 . May be disposed on different radial directions from the center of each anti-stretch wire 1500 may form an angle of 120 degrees with each other from the central axis of the stent body (1100).

At this time, even if the beginning and the end of the covering area of the two adjacent anti-stretching wire 1500 coincides, the potential coupling of the anti-stretching wire 1500 located relatively distally and the rear coupling portion of the anti-stretching wire 1500 located relatively proximal. The portions may not match, and each anti-stretch wire 1500 is provided as a single strand extending between the posterior and posterior junctions located on the stent body 1100, the length of which is the length of each potential junction. And it may be greater than the natural distance between the rear coupling portion.

Also at this time, the three anti-stretching wires 1500 are divided into those located close to the proximal end of the stent body 1100, those located close to the distal end, and those located in between, the three anti-stretch wires 1500 Through this, excessive deformation of the entire length of the stent body 1100 can be prevented. As such, when there are a plurality of anti-stretching wires 1500 provided to the thrombus removal device 1000, the covering area may be considered integrally, and as in the case of FIG. 14 , a plurality of anti-stretching wires 1500 are provided in the stent body When the entire length of 1100 is covered, the covering ratio can be calculated as 100%.

As shown in Figure 16, when the recovery force is applied to the stent body 1100 from the pull wire 1300, each covering area is allowed to increase in length until the anti-stretch wire 1500 is taut, and each different radiation As the anti-stretch wire 1500 located in the direction is in a taut state, the resulting tension may act evenly on the stent body 1100 over the entire stent body 1100 .

In the above description, the stent body of the thrombus removal device has been described as having a single segment form, but the stent body may have a multi-segment form.

Here, the segment may be understood as a unit referring to a mesh structure forming the stent body, and thus, the single segment type stent body means a stent body formed of a single mesh structure, and the multi-segment type stent body is It may mean a stent body including a plurality of mesh structures. That is, the multi-segment may be a form in which the stent body has a plurality of mesh structures spaced apart from each other.

The multi-segment stent body may have a plurality of mesh structures and a bridge connecting the mesh structures to each other. Here, the bridge may be a straight wire or strut in which both ends are respectively connected to two adjacent mesh structures.

The number of bridges may be appropriately changed as needed. 17, which will be described later, shows that the segments are connected by two bridges, but it is also possible to have one bridge or three or more bridges. The bridge is viewed from the longitudinal section of the stent body 11 to prevent the two connecting segments from being twisted together. A symmetrical arrangement may be advantageous.

In addition, the bridge is connected to two adjacent segments, respectively. In this case, the bridge can be connected to the segment through only the end of the segment, as well as being connected to the segment at other points. For example, referring to FIG. 17 , the bridge connects the two segments through the rear end of the segment arranged in the proximal direction and the front end of the segment arranged in the distal direction among the two adjacent segments. However, the segments must be connected through the corresponding point. that is not what

The above-described multi-segment type stent body has an advantage in terms of the primary thrombus compared to the single-segment type stent body.

The multi-segment stent body includes a bridge connecting adjacent mesh structures, and such a bridge may form a mouse structure in the stent body.

Here, the mouse structure may refer to a structure that forms an opening of a relatively large size formed by a bridge, unlike a cell of a mesh structure having a relatively fine opening. The opening formed by the mouse structure generally has a size larger than the size of the thrombus, so that the thrombus can cause inlet retrograde blood flowing into the inner space of the stent body through the opening. In other words, the mouse structure of the present specification may refer to a segment and a region in which a bridge is located between the segments, and a space sufficient for a thrombus to enter the interior of the stent body 11 may be formed between the bridges.

The stent body having the above-described mouse structure can perform thrombus invitation. In particular, the mouse structure has an advantage in attracting the menstrual thrombus, which is difficult to penetrate into the stent body, into the stent body as shown in FIG. 17 to be described later. However, in the present specification, the invitation of blood clots in the function of the mouse structure is not excluded.

On the other hand, it is also possible to form some of the cells of the mesh structure as enlarged cells having a size larger than that of a thrombus. . Therefore, in the present specification, the mouse structure should not be understood as including the expanded cell from a mechanical point of view, but should be understood as a generic term including the expanded cell from a functional point of view depending on the context.

In addition, the space between the bridges may be referred to as an expansion cell, or an inlet, which is larger than other cells of the stent body, and the size of the inlet may be determined by the length of the bridge and the diameter of the segment. In addition, when the stent body is deformed by the lateral force during the recovery process of the thrombus removal device, the size and shape of the inlet may be deformed as the diameter of the segment is reduced.

Hereinafter, with respect to the anti-stretch wire of the thrombus removal device having a multi-segment stent body, a thrombus removal device in which the stent body has two segments and a thrombus removal device in which the stent body has three segments will be described as examples. do. However, the shape of the multi-segment is not limited to a dual segment type or a triple segment type, and in the examples described below, the number of segments of the stent body is different from the mentioned example. It will be fully understood by those skilled in the art.

17 is a diagram illustrating an example of a thrombus removal device according to another embodiment of the present specification, FIG. 18 is a diagram illustrating an example of a shape modification of the thrombus removal device according to FIG. 17 , and FIG. 19 is FIG. 17 It is a view related to another example of the shape deformation of the thrombus removal device according to the present invention.

Referring to FIG. 17 , the stent body 1100 of the thrombus removal device 1000 according to this example has two segments 1110 and 1130 and a bridge 1123 connecting the two segments 1110 and 1130 - FIG. 20 . hereinafter referred to as a first bridge - and a mouth structure 1120 formed between the two segments 1110 , 1130 - referred to as a first mouse hereinafter in FIG. 20 . The segments 1110 and 1130 may be provided as a mesh structure by struts. In addition, the bridge 1123 may be provided in the form of a wire having both ends connected to the distal portion of the mesh structure on the proximal side and the proximal portion of the mesh structure on the distal direction side and extending between both ends, the central axis of the stent body 1100 . may be disposed on different radial directions from The bridge 1123 may form a mouse structure 1120 between the two segments.

Referring to FIG. 18 , the thrombus removal device 1000 described above may be deployed and deployed at a treatment point. The thrombus near the treatment point may be invited into the stent body 1100 through the mouse structure 1120 during the deployment process or the recovery process of the stent body 1100 through the pull wire 1300 after deployment. Here, when the recovery force is applied to the stent body 1100 through the pull wire 1300, each segment 1110, 1130 of the stent body 1100 of the thrombus removal device 1000 according to the present example increases its length. Accordingly, the shape may be deformed, and accordingly, the size of the entrance of the mouse structure 1120 may be deformed, and the thrombus invitation may not be smoothly made. On the other hand, even when the anti-stretching wire 1500 is installed only in a single segment 1110 in the thrombus removal device 1000 shown in FIG. 17, the anti-stretching wire 1500 is not installed as shown in FIG. 19, the segment 1110, Formation deformation is induced in 1130 , so that the size of the entrance of the mouse structure 1120 may also be deformed. In addition, as shown in FIGS. 18 and 19 , in addition to the deformation of the entrance of the mouse structure 1120 , an overall diameter change occurs, so that the thrombus removal may not be performed smoothly.

Therefore, it may be preferable that the anti-stretching effect is applied to the segments constituting the stent body as a whole in the thrombus removal device using the multi-segment stent body.

An anti-stretch wire may be provided in a thrombus removal device having a multi-segment stent body so that a covering region is disposed on each segment.

According to an example, a single anti-stretch wire is included in the thrombus removal device, and the thrombus removal device may suppress an increase in the length of the stent body by using the single anti-stretch wire. Here, one point of the segment (eg, one point of the proximal portion of the proximal side segment) disposed in the most proximal direction among the plurality of segments and one of the segments disposed in the distal direction among the plurality of segments related to the single anti-stitching wire It may be located at a point (eg, a point on the distal portion of the distal side segment). Accordingly, a covering area is formed for each segment of the stent body, and a single anti-stretching wire can suppress an increase in length of all segments.

According to another example, the thrombus removal device may include a plurality of anti-stretching wires, and the thrombus removal device may suppress an increase in the length of the stent body by using the plurality of anti-stretching wires. Here, the plurality of anti-stretch wires may be installed for each segment. Accordingly, a covering area is formed for each segment of the stent body, and a plurality of anti-stretch wires may suppress an increase in length of all segments.

According to another example, a plurality of anti-stretch wires may be included in the thrombus removal device, and a coupling portion related to at least some of the plurality of anti-stretch wires may be formed in a plurality of segments. For example, two anti-stretching wires are installed in a stent body having three segments, one anti-stretching wire is connected to the segment located in the middle and the most proximal side, and the other anti-stretching wire is in the middle. It may be connected to a positioned segment and a segment on the distalmost side. Here, the covering areas of the plurality of anti-stretch wires may overlap, be spaced apart, or be formed so that the end point of one covering area and the start point of the other covering area coincide.

On the other hand, the covering ratio of the anti-stretch wire provided to the stent body in the form of a multi-segment can be calculated excluding the mouse structure. Specifically, in the multi-segment type stent body, the covering area may be a mesh structure area in which an anti-stretching effect occurs by an anti-stretching wire, and the covering ratio is the length of the entire covering area with respect to the total length of the mesh structures except for the mouse structure. can be defined as the ratio of

In addition, the anti-stretch wire may be provided in consideration of the position of the bridge to the thrombus removal device having a multi-segment stent body.

When the anti-stretching wire is connected over at least two segments to the multi-segmented stent body, the size of the opening of the mouth structure formed between the adjacent segments by the bridge connecting the adjacent segments as described above is the anti-stretching wire. can be determined by

For example, the anti-stretch wire connected between two adjacent segments may be located on the same line as the bridge. Since the anti-stretch wire thus arranged does not cross the opening formed by the bridge, it may not inhibit the invitation of the thrombus through the opening of the bridge. This may be interpreted as not reducing the size of the opening of the mouth structure by the anti-stretching wire. As a more specific example, in the case of a stent body in which two adjacent segments are connected by two bridges disposed to face each other in the radial direction from the central axis, the anti-stretch wire connected between the two adjacent segments may be positioned on the same line as the bridge. can

As another example, the anti-stretch wire connected between two adjacent segments may be positioned on a different line from the bridge. Since the anti-stretch wire arranged in this way crosses the opening formed by the bridge, it is possible to prevent the thrombus from leaving through the opening of the bridge. This may be interpreted as reducing the size of the opening of the mouth structure by the anti-stretching wire. As a more specific example, in the case of a stent body in which two adjacent segments are connected by two bridges disposed to face each other in a radial direction from a central axis, two anti-stretch wires connected between two adjacent segments are each viewed in a longitudinal section It may be arranged to form a right angle with the bridge so that four openings are formed in the mouse structure.

On the other hand, the anti-stretch wire connected across at least two segments may perform the function of a bridge. For example, two anti-stretch wires connecting between adjacent segments may be two bridges. As another example, there is one bridge between adjacent segments, and the anti-stretching wire connecting the adjacent segments is positioned symmetrically with the bridge, so that it can have substantially the same effect as two segments are connected by two bridges. .

Hereinafter, examples of the anti-stretch wire of the thrombus removal device having a multi-segment stent body will be described with reference to FIGS. 20 to 24 .

Referring to FIG. 20 , according to this example, two anti-stretching wires 1500 are provided (referred to as 1510 and 1520 in the drawing), and may be provided in a form to prevent an increase in the length of each segment.

The coupling portion to which each anti-stretching wire 1500 is connected is located in one segment, respectively, and the extension extending between the coupling portion and the connecting portion of the anti-stretching wire 1500 connected to the coupling portion may be longer than the natural length between the two coupling portions. . In this case, the extension may cross the inner region of the cell 1103 of the segment, but may be disposed not to cross the mouth of the mouth structure.

On the other hand, in FIG. 20, two anti-stretch wires 1500 are shown to be located in different radial directions from the center of the stent body 1100, but this is not necessarily the case, and may be located in the same radial direction, and symmetrically to each other. may be placed.

When the stent body 1100 is pulled according to the manipulation of the pull wire 1300, the length increase of the first segment 1110 and the second segment 1130 is through the first wire 1510 and the second wire 1520. It may be limited within a certain range. Accordingly, since the diameter sizes of the first segment 1110 and the second segment 1130 are maintained within a certain range, the size of the first mouse 1120 is not excessively reduced and the shape of the first mouse 1120 is excessively distorted. may not support Through this, the entrance of the first mouse 1120 may have a size sufficient for the thrombus to enter.

Referring to FIG. 21 , according to this example, the anti-stretch wire 1500 may be provided as one, and may be provided in a form to prevent an increase in length of two adjacent segments. The two coupling parts to which the anti-stretching wire 1500 are connected are located in different segments, and the extension extending between the coupling part and the connecting part of the anti-stretching wire 1500 connected to the coupling part is provided longer than the natural length between the two coupling parts, so the initial deployment It can have a loose shape in the state.

In addition, the two coupling portions of the anti-stretching wire 1500 may be located on a virtual straight line extending along any one of the two first bridges 1123, and through this, the anti-stretching wire 1500 is the first bridge 1123 ) can be provided in a form that does not cover the entrance of the mouse structure by being placed side by side along the .

When the stent body 1100 is pulled according to the manipulation of the pull wire 1300, the diameter size of the first segment 1110 and the second segment 1130 is maintained within a certain range, whereby the size of the first mouse 1120 is excessive. It may not be reduced or crushed. Even when the first bridge 1123 includes a bend, length deformation of the first bridge 1123 through the bridge-type anti-stretch wire 1520 may be limited. As such, the first mouse 1120 may have a size sufficient to bind with a thrombus.

Referring to FIG. 22 , the stent body 1100 of the thrombus removal device 1000 according to the present example may have three segments, and two mouse structures may be formed between the segments. In this case, the bridges forming each mouse structure may be alternately arranged for each mouse structure. When the mouse structures are arranged alternately, the inflow directions of the openings by the mouse structures may be formed differently, so that there may be an advantage in that the inflow directions of the thrombus located outside the thrombus removal device are diversified.

Referring back to FIG. 22, the anti-stretching wire 1500 according to this example may be three (referred to as 1510, 1520, and 1530 in the drawing), and to prevent an increase in the length of each segment as in FIG. may be provided in the form.

Here, the three anti-stretch wires 1500 may be disposed symmetrically with respect to the center of the stent body 1100, that is, in a form that forms an angle of 120 degrees with each other from the central axis of the stent body 1100, but this is not necessarily the case. , taking into account the anti-stretching effect and design advantages, it can be appropriately arranged.

Also, here, the coupling portion to which each anti-stretching wire 1500 is connected is located in one segment, respectively, and the extension extending between the coupling portion and the connecting portion of the anti-stretching wire 1500 connected to the coupling portion is greater than the natural length between the two coupling portions. It can be provided for a long time. Through this, when a lateral force is applied to the stent body 1100 , the length of each segment may increase within the length of the extension.

Specifically, when the stent body 1100 is pulled according to the manipulation of the pull wire 1300, the length increase of the first segment 1110, the second segment 1130 and the third segment 1150 is three anti-stretch wires Through 1500, it can be limited within a certain range, and by preventing the diameter change of each segment in this way, the size and shape of the first mouse 1120 and the second mouse 1140 can be maintained at a level that is easy for the thrombus to pass through. can

Referring to FIG. 23 , the stent body 1100 of the thrombus removal device 1000 of this example may have three segments and two mouse structures, and the anti-stretch wire 1500 of the thrombus removal device 1000 is shown in FIG. 22 . It may be arranged differently from that shown in .

In other words, there may be two anti-stretching wires 1500 of the thrombus removal device 1000 of this example (referred to as 1510 and 1520 in the drawing), and as shown in FIG. 21 , each anti-stretching wire 1500 is adjacent to each other. It may be provided in a form that prevents an increase in length of the two segments.

Here, the two coupling portions of each anti-stretching wire 1500 may be located in different segments, and the rear coupling portion of the anti-stretching wire 1510 located relatively proximal and the anti-stretching wire 1520 located relatively distally. The second segment 1130 in which the potential coupling part is located may be affected by the two anti-stretch wires 1500, and the anti-stretching effect may be adjusted according to the positional relationship between the above-described back coupling part and the potential coupling part. can

Also, here, the two coupling portions to which one anti-stretching wire 1500 is connected may be positioned adjacent to a virtual straight line extending along the bridge with one bridge therebetween. In other words, the two connecting portions connected to the two connecting portions of the anti-stretching wire 1510 located relatively proximal are located on the same line as the first bridge 1123, and the two connecting portions of the anti-stretching wire 1520 located relatively distally and Since the two connecting portions to be connected are located on the same line as the second bridge 1143 , an extension extending between the two connecting portions may be disposed along the first bridge 1123 and the second bridge 1143 . Through this, the radial positions of the plurality of anti-stretch wires 1500 provided in the thrombus removal device 1000 may be designed to be substantially similar to the radial positions of the two bridges 1123 and 1143 .

At this time, the length of the extension may be provided longer than the natural length between the two coupling portions, and through this, the anti-stretching wire 1500 having a slack during initial deployment is in a taut state as the length of each segment increases, and the anti-stretching wire 1500 may be disposed side by side on the first bridge 1123 and the second bridge 1143 .

Referring back to FIG. 23 , the pull wire 1300 of this example may be connected from the surface side of the mesh structure of the stent body 1100 , and the pull wire 1300 is connected to the stent body 1100 and the anti-stretch wire Two coupling portions to which one of 1500 is connected may be located on substantially the same straight line. Through this, there is an advantage that the recovery force and the tension acting on the stent body 1100 can act on the same line. By matching with 1300 , shape deformation of the proximal portion of the stent body 1100 , or the first segment 1110 , which may easily increase its length compared to other regions, can be effectively prevented.

When a lateral force is applied to the stent body 1100 according to the manipulation of the pull wire 1300 in the recovery process of the thrombus removal device 1000 , the first segment 1110 , the second segment 1130 , and the third segment 1150 ) The increase in length may be limited within a certain range through the two anti-stretching wires 1500, through which the size and shape of the first mouse 1120 and the second mouse 1140 are at a level at which a thrombus can easily pass through. can be maintained

Referring to FIG. 24 , the anti-stretching wire 1500 of the thrombus removal device 1000 of this example may be two, one 1520 of which is in the form of the anti-stretching wire 1500 of FIG. 20 , the other 1510 ) may be provided in the form of the anti-stretch wire 1500 of FIG. They may be located on the same line.

As described above, when the pull wire 1300 is connected to the stent body 1100 and the coupling portion where the anti-stretch wire 1500 is connected to the thrombus removal device 1000 is substantially on the same straight line, anti-stretch The anti-stretch effect by the wire 1500 may have an advantage in acting on the stent body 1100 . Therefore, in order to arrange all of the anti-stretching wires 1500 provided to the thrombus removal device 1000 on the same line as the pull wires 1300, some of the anti-stretching wires 1500 are in the form of FIG. 20, and the other part is in the form of FIG. It may be provided as, it is also possible that the anti-stretch wire 1500 is implemented in other forms not mentioned in the above description.

On the other hand, the anti-stretch wire 1500 having a loose state during initial deployment may be in a taut state as the length of the stent body 1100 is changed by the recovery force applied to the stent body 1100, and having a taut state The anti-stretching wire 1500 may limit an additional increase in length of the stent body 1100 by applying a tension in the opposite direction to the recovery force to the stent body 1100, at this time each anti-stretching wire 1500 is a pull As the wire 1300 is positioned substantially on the same line as a point of the stent body 1100 to which the wire 1300 is connected, the effect can be properly exhibited.

In the above description, the thrombus removal device having a single stent body of single segment or multi-segment has been described, but the thrombus removal device may include a plurality of stent bodies.

The independent stent body may refer to a single mesh structure or a set of mesh structures forming a unibody. In other words, an independent stent body may mean a mesh structure not connected to another mesh structure or a set thereof (a mesh structure or a group thereof). For example, when a plurality of mesh structures are connected to each other through a bridge or the like, even if there are a plurality of mesh structures, this may be interpreted as a single stent body. However, when the plurality of mesh structures are not connected to each other, the plurality of mesh structures should be interpreted as a plurality of stent bodies.

Here, the mesh structures that are not connected to each other may mean that the recovery force applied to move one mesh structure is not transmitted to the other mesh structure. Therefore, in general, it is difficult for the plurality of stent bodies to transmit force to each other, and individual pull wires may be connected to each of the plurality of stent bodies. In other words, the mesh structures connected to different pull wires may be understood as different stent bodies.

In addition, a mesh structure that is not connected to each other may mean a mesh structure that can operate independently of each other. For example, if each mesh structure is connected to a different pull wire so that a relative movement between the mesh structures is possible according to manipulation of a plurality of pull wires, this may be understood as a mesh structure that is not connected to each other. Of course, even if a plurality of pull wires can be simultaneously manipulated to move the mesh structure together, this should still be understood as an independent mesh structure.

On the other hand, the mesh structures that do not operate substantially integrally by the recovery force through the pull wire, etc. may be understood as separate stent bodies, even if they are connected by simple struts, strings, or wires, etc., which are difficult to transmit the recovery force. will be. Similarly, even if a plurality of pull wires are equally manipulated by a single user's manipulation in the form of a plurality of pull wires being fastened to each other and the plurality of mesh structures are moved integrally, this will also be understood as a separate stent body.

Hereinafter, a multi-body type thrombus removal device will be described based on a thrombus removal device (dual body type thrombus removal device) including two stent bodies. However, it should be noted in advance that the number of stent bodies of the multi-body type thrombus removal device does not necessarily have to be two.

25 is an exploded perspective view of an example of a thrombus removal device according to another embodiment of the present specification, FIGS. 26 and 27 are views of different states of the thrombus removal device according to FIG. 25 , and FIG. 28 is It is a side view related to the operation of the thrombus removal device according to FIG. 25 , and FIG. 29 is an exploded view related to the operation of the thrombus removal device according to FIG. 25 .

Referring to FIG. 25 , the thrombus removal device 1000 according to the present example may include two stent bodies 1100A and 1100B (hereinafter referred to as (1100)). Each stent body 1000 may include a segment and a mouse structure. Each stent body 1100 is connected to the pull wire 1300 and operated independently, so that the positional relationship between the two stent bodies 1100 can be changed. Through this, the thrombus removal device 1000 may be modified into a shape suitable for capturing a soft thrombus or a shape suitable for capturing a menstrual thrombus.

The thrombus removal device 1000 may be deformed between a first state and a second state.

Here, the first state may be a form suitable for engaging with a thrombus. Accordingly, when the thrombus removal device 1000 is in the first state, it may be referred to as the operation of the thrombus removal device 1000 in a clot engaging mode. In addition, since the coupling of the stent body 1100 and the thrombus is mainly related to the thrombus, it may be referred to as a thrombus mode (soft-clot mode). Also, as will be described later, in the thrombus coupling mode of the thrombus removal device 1000 , the mouse structure of the two stent bodies 1100 is staggered and the mouse structure and the mesh structure are staggered, so that the mouse structure of the one stent body 1100 is different. Since it may be implemented by being closed due to the mesh structure of 1100 , the thrombus removal device 1000 may be referred to as having a closed configuration with respect to the first state.

Also, here, the second state may be a form suitable for inviting and capturing a thrombus. Accordingly, when the thrombus removal device 1000 is in the second state, it may be referred to as the operation of the thrombus removal device 1000 in a clot inviting mode or a clot capturing mode. In addition, since the invitation and reception of the stent body 1100 and the thrombus is mainly related to the menstrual thrombus, this may be referred to as a hard-clot mode. Also, as will be described later, in the thrombus invitation mode or the thrombus capture mode of the thrombus removal device 1000 , the two stent bodies 1100 are arranged so that the mouse structure and the mesh structure are arranged to match each other (correspoing to each other), so that one stent body Since the mouse structure of 1100 and the mouse structure of the other stent body 1100 overlap each other and can be implemented by opening the opening of the mouse structure, the thrombus removal device 1000 is in the second state to remove the thrombus The device 1000 may also be referred to as having an open configuration.

On the other hand, as described above, it is clarified in advance that the term thrombus mode excludes the binding of the thrombus, or, conversely, the term thrombus mode does not exclude the binding of the thrombus. Similarly, the term thrombus binding mode It should be noted in advance that the invitation is not excluded, or conversely, the thrombus capture mode does not exclude the binding of the thrombus.

More specifically, referring to FIG. 25 , the two stent bodies 1000 may include a first stent body 1100A and a second stent body 1100B.

Both the first stent body 1100A and the second stent body 1100B may be the above-described multi-segment stent body 1000 .

The first stent body may include three segments and two mouse structures as shown in FIG. 25 . Here, the three segments may include a first segment 1110A, a second segment 1130A, and a third segment 1150A arranged in an order from proximal to proximal. Also here, the two mouse structures are a first mouse 1120A positioned between the first segment 1110A and the second segment 1130A, and a second mouse positioned between the second segment 1130A and the third segment 1150A. A mouse 1140A may be included.

The second stent body 1100B may include two segments and one mouse structure as shown in FIG. 25 . Here, the two segments may include a fifth segment 1110B and a sixth segment 1130B arranged in an order from proximal to proximal. Also, here, the mouse structure may include a fifth mouse 1120B positioned between the fifth segment 1110B and the sixth segment 1130B.

On the other hand, in the description with reference to FIG. 25, it has been described that both the first stent body 1100A and the second stent body 1100B have a multi-segment shape, but both stent bodies 1100 must be in a multi-segment shape. not. In other words, in the present specification, the dual body type thrombus removal device 1000 is a stent body of a suitable shape to perform a function of opening/closing the opening of the mouse structure according to the positional relationship between the two stent bodies 1100 . 1100 , which may be implemented in various forms.

Specifically, the stent body 1100 of any one of the two stent bodies 1100 may be provided in a multi-segment form, and thus may include at least one mouse structure. In addition, the other stent body 1100 of the two stent bodies 1100 may have segments equal to or greater than the number of mouse structures of any one stent body.

For example, looking back at the thrombus removal device 1000 described with reference to FIG. 25 described above, the first stent body 1100A is provided as a triple segment stent body having two mouse structures, and the second stent body 1100B is provided as a stent body 1100 in the form of a double segment having two segments equal to the number of mouse structures of the first stent body 1100A.

For another example, when any one stent body 1100 is provided in the form of a quadruple segment, the other stent body 1100 may be provided in the form of a triple segment. For another example, when any one stent body 1100 is provided in a double segment form, the other stent body 1100 may be provided in a single segment form. As another example, both stent bodies 1100 may be provided in a double segment form or a triple segment form.

That is, the dual body type thrombus removal device 1000 of the present specification includes one stent body 1100 provided in a multi-segment form and the other stent body 1100 provided in a multi-segment form or a single segment form. The number of segments of the other stent body 1100 should be equal to or greater than the number of the mouse structures of any one stent body 1100 . In general, since the number of mouse structures is one less than the number of segments, the dual body type thrombus removal device 1000 of the present specification may be the same as or different from the number of segments of the two stent bodies 1100 by one.

On the other hand, as described above, in order to open/close the opening of the mouse structure according to the positional relationship of the two stent bodies 1100, the length of the mouse and the segment corresponding to each other of the two stent bodies are substantially the same. may be desirable.

Referring back to FIG. 25 , any one of the two stent bodies 1100 may be located inside the other one. For example, the second stent body 1100B may be located on the inside of the first stent body 1100A, or conversely, the first stent body 1100A may be located on the inside of the second stent body 1100B. In other words, the second stent body 1100B may be inserted into the first stent body 1100A or the first stent body 1100A may be inserted into the second stent body 1100B. However, hereinafter, for convenience of description, the second stent body 1100B is positioned on the inside of the first stent body 1100A.

In this example, any one stent body 1100 is inserted into another stent body, but in a first state to be described later, the mesh structure of the first stent body 1100A and the mesh structure of the second stent body 1100B are single In order to form a shape similar to one mesh structure, the diameter of the two stent bodies 1100 is substantially the same, or the diameter of the stent body 1100 inserted therein is smaller than the diameter of the stent body 1100 disposed outside, but almost It could be a similar number.

Accordingly, the circumferential surface of the first stent body 1100A and the circumferential surface of the second stent body 1100B may extend on substantially the same plane, and the mesh structures of the two stent bodies 1100 are alternately arranged (first state), it can behave like a single mesh structure.

Meanwhile, the thrombus removal device 1000 of this example may optionally include a basket 1900 , and the basket may be disposed at the distal end of at least one of the two stent bodies 1100 . Here, the basket 1900 may be advantageously disposed on the stent body 1100 disposed on the outside of the two stent bodies 1100 .

Referring back to FIG. 25 , the thrombus removal device 1000 according to the present example may include two pull wires 1300A and 1300B, hereinafter referred to as 1300 . Specifically, the first pull wire 1300A of the two pull wires may be connected to the first stent body 1100A, and the second pull wire 1300B may be connected to the second stent body 1100B. Accordingly, force may be transmitted to each stent body 1100 .

In addition, the two pull wires 1300 may be selectively coupled. In a state in which the coupling between the two pull wires 1300 is released, each pull wire 1300 may be operated independently. In addition, in a state in which the two pull wires 1300 are coupled to each other, the two pull wires 1300 may be operated integrally. Accordingly, in the state in which the coupling of the two pull wires 1300 is released, the user can independently operate the two stent bodies 1100, and in the state in which the two pull wires 1300 are coupled, the user can use the two stent bodies ( 1100) can be operated integrally. For example, for a change between a first state and a second state of the thrombus removal device 1000 to be described later, the user uses the pull wire 1300 in a state in which coupling is released between the two stent bodies 1100 relative positions can be adjusted. For another example, in order to move the thrombus removal device 1000 while fixing the state of the thrombus removal device 1000 to be described later as the first state or the second state, the user may use the pull wire 1300 coupled to each other. By using the two stent bodies 1100 can be moved integrally. Of course, it is not necessary to combine the two pull wires 1300 to move the two stent bodies 1100 as one, for example, even if the same operation is separately applied to the two pull wires 1300 at the same time, the pull wire ( 1300) can obtain the same effect as operating in the combined state. However, since an error may occur by the user in inputting the same operation to the two pull wires 1300 that are not physically coupled compared to those in which the pull wire 1300 is physically coupled, the two pull wires 1300 are physically It may be advantageous to combine the two stent bodies 1100 as one.

For example, the coupling of the two pull wires 1300 may be physically made, for example, may be implemented in the form of a locking mechanism or the like.

According to one example, any one of the two pull wires 1300 is provided as a hollow wire, and the other one may be inserted into any one. In this case, the locking structure may release the coupling between the two pull wires 1300 by applying pressure to the hollow wire from the outside to couple the two wires by frictional force between the two pull wires 1300 or release the pressure. The lock can be operated by a user or a robot.

According to another example, two pull wires 1300 are disposed adjacent to each other along the longitudinal side of each other, and two pull wires 1300 overlap each other in the longitudinal direction of the two pull wires 1300. 1300), it is also possible to implement a locking structure in the form of fastening or releasing the fastening.

Also, the thrombus removal device 1000 may optionally further include an anti-rotating mechanism. The anti-rotation structure may prevent relative rotation between the two stent bodies 1100 .

When the two stent bodies 1100 rotate relatively, the arrangement relationship between the bridges of the mouse structure included in the two stent bodies 1100 may be changed, and accordingly, the size of the opening of the mouse structure may be changed. The anti-rotation structure prevents the relative rotation of the two stent bodies 1100, thereby maintaining a constant relative positional relationship between the bridges of the two stent bodies 1100, thereby maintaining a constant size of the opening of the mouth structure.

Here, the anti-rotation structure may indirectly prevent the relative rotation between the two stent bodies 1100 by preventing the rotation between the two pull wires 1300 .

For example, the anti-rotation structure for preventing rotation between the two pull wires 1300 is formed on the inner diameter surface of the pull wire 1300 provided in a hollow shape and the outer diameter surface of the pull wire 1300 inserted therein. It may be provided in a pattern that is complementary to each other and inhibits relative rotation. Specifically, the anti-rotation structure may be provided in a rectangular or cross-sectional pattern formed on the inner diameter surface of the outer pull wire 1300 and the outer diameter surface of the inner pull wire 1300 .

As described above, the thrombus removal device 1000 according to the present example may be in the first state or the second state according to the relative positional relationship between the two stent bodies 1100 .

When the thrombus removal device 1000 is in the first state, the two stent bodies 1100 are arranged to close the opening of the mouth structure of one stent body 1100 and the segment of the other stent body 1100 to close. can Specifically, as the segments (or mouse structures) of the two stent bodies 1100 are alternately arranged, the thrombus removal device 1000 may have a first state.

Specifically, referring to FIG. 26 , at least one of the segments of the second stent body 1100B is disposed to correspond to at least one of the mouse structures of the first stent body 1100A, so that the mouse structure may be closed by the segment. In other words, the mouth structure of the first stent body 1100A may be covered by the segment of the second stent body 1100B, and the mouse structure of the second stent body 1100B is the first stent body 1100A. ) can be obscured by a segment of Accordingly, the openings of the mouse structures are closed, and in appearance, the two stent bodies 1100 may have a shape similar to that of forming one mesh structure. As such, when the stent bodies 1100 have a shape similar to a single mesh structure in the form of a single tube as a whole, from the most proximal point to the most distal point of the two stent bodies 1100 to combine with a thrombus through a cell structure or mesh structure. This can facilitate thrombus binding.

When the thrombus removal device 1000 is in the second state, the two stent bodies 1100 may be disposed such that the mouse structures overlap each other. Specifically, as the segments (or mouse structures) of the two stent bodies 1100 are arranged at positions corresponding to each other, the thrombus removal device may have a second state.

Specifically, referring to FIG. 27 , at least one of the segments of the second stent body 1100B is disposed to correspond to at least one of the segments of the first stent body 1100A, thereby opening the mouse structure. In other words, the mouth structure of the first stent body 1100A may be opened by the mouth structure of the second stent body 1100B, and the mouth structure of the second stent body 1100B is the first stent body 1100A. Can be opened by mouse structures. Accordingly, the openings of the mouse structures are opened, and the thrombus removal device 1000 may have a shape similar to the single stent body 1100 having a multi-segment shape having a mouse structure in appearance. When the mouse structure is formed by the stent bodies 1100 as described above, it may be easy to invite a thrombus through the mouse structure.

The thrombus removal apparatus 1000 according to the present example may perform a state transformation between the first state or the second state according to the relative movement of the two stent bodies.

Specifically, in a state in which the coupling between the two pull wires 1300 is released, by manipulating any one pull wire 1300 to move any one of the two stent bodies 1100, the state transformation between the first state and the second state is can be performed.

28 and 29 , the thrombus removal device 1000 may initially have a first state. In detail, the thrombus removal device 1000 may have a first state because the opening region of the mouth structure of the first stent body 1100A is covered by the segment of the second stent body 1100B. That is, the first mouse 1120A is disposed to correspond to the fifth segment 1110B, the second mouse 1140A is disposed to correspond to the sixth segment 1130B, and the fifth mouse 1120B of the second stent body 1100B). is disposed to correspond to the second segment 1130A of the first stent body 1100A, so that the thrombus removal device may have a first state.

At this time, in the state in which the coupling of the first pull wire 1300A and the second pull wire 1300B is released, the first stent body 1100A is not subjected to manipulation, and only the second pull wire 1300B is operated to the second The stent body 1100B may be moved in the proximal direction in the longitudinal direction of the stent body. When the second stent body 1100B is moved through the second pull wire 1300B until the mice of the two stent bodies 1100 overlap each other, the thrombus removal device 1000 has a second state. can

Of course, unlike the above, it is also possible to change the state of the thrombus removal device 1000 by moving the first stent body 1100A to change the state or by moving it in the distal direction instead of the proximal direction. In addition, as opposed to changing the state of the thrombus removal device 1000 from the first state to the second state, it is of course possible to change the state from the second state to the first state.

On the other hand, when the segment of the first stent body 1100A and the segment of the second stent body 1100B overlap each other and the thrombus removal device reaches the second state, the distance between the struts 1101 may be adjusted. For example, when the cell 1103 of the first segment 1110 and the cell 1103 of the fifth segment 1110B partially overlap each other, the strut 1101 in contact with the thrombus in the thrombus removal device 1000 is can be densely located. Through this, the strut 1101 of the thrombus removal device 1000 may be easily coupled to the thrombus.

In the case of the thrombus removal device 1000 including the plurality of stent bodies 1100 described above and capable of being deformed between the first state and the second state according to the positional relationship between the stent bodies 1100, one stent body Unlike the thrombus removal device 1000 having 1100 , length deformation may occur in the process of relatively moving the stent body 1100 for state change as well as the recovery process.

In addition, since the aforementioned thrombus removal device 1000 uses a mouse structure and segment having substantially the same length, the segment of one stent body 1100 closes or opens the mouse of the other stent body 1100, It may be important that the length ratio between the segment and the mouse structure remains constant. Specifically, the mouth structure formed by the bridge provided in the form of a wire and having little length deformation due to lateral force maintains a substantially constant length even when a force in the longitudinal direction such as recovery force is applied, but the segment formed by the mesh structure is Since length deformation occurs easily by the force in the longitudinal direction, the length of the segment becomes larger than the length of the mouse structure during the recovery process or the relative movement between the two stent bodies 1100, so even if the mouse and the segment are placed in the corresponding positions, a part of the mouse structure is likely to be obscured by the segment.

30 is a view of an example of a shape modification of the thrombus removal device according to FIG. 25 .

Referring to FIG. 30 , when a lateral force for state transformation is applied to only one stent body 1100 to the thrombus removal device 1000 including a plurality of stent bodies 1100 , the segments of the stent body 1100 are When the length increases, the length of the segment becomes larger than the length of the mouse structure, and this causes the entrance of the mouse structure to be partially opened or cannot be opened, so that the thrombus removal device 1000 reaches the second state. it may be impossible

Accordingly, the anti-stretch wire 1500 is included in the thrombus removal device 1000 including a plurality of stent bodies 1100 and deformable between the first state and the second state according to the positional relationship between the stent bodies 1100 . can The anti-stretch wire 1500 may be provided to the first stent body 1100A and the second stent body 1100B, respectively.

Hereinafter, examples of the anti-stretch wire 1500 of the thrombus removal device 1000 having a plurality of stent bodies 1100 will be described with reference to FIGS. 31 to 35 .

31 to 35 are diagrams illustrating examples of a thrombus removal device according to another embodiment of the present specification.

31 to 34 , the stent body 1100 of the thrombus removal device 1000 according to the present examples includes a first stent body 1100A and a second stent body 1100B.

Here, except for FIG. 35 provided in the form of a single segment, the stent body 1100 of FIGS. 31 to 34 is provided in a multi-segment form, and the first stent body 1100A has three segments and two mouse structures. , the second stent body 1100B includes two segments and one mouse structure.

In addition, the first pull wire 1300A and the second pull wire 1300B connected to each of the stent bodies 1100 are disposed on the surface side of each stent body 1100, and the two pull wires 1300 are on the same line It can be independently operated by being disposed on the pole, or can be operated integrally by coupling.

Referring to Figure 31, the anti-stretching wire 1500 according to this example is a first anti-stretching wire 1500A and a second stent body 1100B to prevent an increase in the length of the first stent body 1100A. and a second anti-stretch wire 1500B to prevent it. Here, the first anti-stretching wire 1500A and the second anti-stretching wire 1500B may be provided in a form to prevent an increase in the length of each segment as shown in FIGS. 20 and 22 .

Specifically, the first anti-stretch wire 1500A provided to the first stent body 1100A having three segments may be three (1510A, 1520A, 1530A), and each first anti-stretch wire 1500A is The two coupling portions to be connected may be located on one segment. In addition, the second anti-stretch wire 1500B provided to the second stent body 1100B having two segments may be two (1510B, 1520B), and each second anti-stretch wire 1500B is connected to two The coupling portion may be located on one segment.

Here, according to the design, the potential coupling portion for the anti-stretch wires 1510A and 1510B connected to the most proximal segment among the segments of one stent body 1100 may be located on the pull wire 1300, and connected to the most distal segment The back coupling for the anti-stretch wires 1530A, 1520B may be located on the basket 1900 .

Referring back to FIG. 31 , a plurality of anti-stretching wires 1500 provided in one stent body 1100 are shown to be located in the same direction from the center of the stent body 1100, which is an anti-stretching wire 1500 . The coupling portion to which is connected may be designed to be located on the same line as the connection point between the pull wire 1300 and the stent body 1100, and the advantage thereof may be described with reference to the above-described content.

On the other hand, in the thrombus removal device 1000 whose shape is deformed according to the relative positional relationship of the stent body 1100, the length or diameter difference value between the two stent bodies 1100 is maintained similar to the initial deployment state. can be beneficial Therefore, in order to suppress the length deformation of the two stent bodies 1100, the length of each anti-stretch wire 1500 may be provided equal to the natural distance between the two coupling portions, but this is not necessarily the case, and the two stent bodies ( 1100) may be provided longer to account for a range that allows an increase in length.

On the other hand, in the thrombus removal device 1000 whose shape is changed to the first state or the second state, the interference between the stent body 1100 of which the positional relationship is changed may preferably be minimized, and the anti-stretch wire The arrangement of 1500 may be determined in consideration of this.

In addition, in the thrombus removal device in the second state in which a portion of the first stent body 1100A and the second stent body 1100B overlap, a portion of the thrombus removal device 1000 overlaps each other in the second state has the same shape It may be advantageous to have, for this purpose, the radial position of the anti-stretch wire 1500 provided to the two stent bodies 1100 may be determined. For example, as shown in FIG. 31 , the first anti-stretch wire 1500A and the second anti-stretch wire 1500B may be positioned in the same radial direction from the central axis of the stent body 1100 .

Either one of the two stent bodies 1100 moves according to the operation of the two pull wires 1300 that are released, or the two stent bodies 1100 move at the same time according to the operation of the two pull wires 1300 that are coupled When an external force is applied to the two stent bodies 1100, the length increase of the first stent body 1100A and the second stent body 1100B is a first anti-stretching wire (1500A) and a second anti-stretching wire (1500B). may be limited through Accordingly, the length ratio of the first stent body 1100A and the second stent body 1100B can be maintained similarly throughout before and after the pull wire 1300 operation, and the thrombus removal device 1000 is in the first state or the second Its shape is deformed to the state, and the mouse structure can be opened and closed.

Referring to Figure 32, the anti-stretching wire 1500 according to this example is the first anti-stretching wire 1500A and the second stent body 1100B to prevent an increase in the length of the first stent body 1100A. and a second anti-stretch wire 1500B to prevent it. Here, the first anti-stretching wire 1500A and the second anti-stretching wire 1500B may be provided in a form to prevent an increase in length of two adjacent segments as shown in FIGS. 21 and 23 .

Specifically, the first anti-stretch wire 1500A provided to the first stent body 1100A having two segments may be two (1510A, 1520A), and each coupling portion may be located in a different segment. In addition, the second anti-stretch wire 1500B provided to the second stent body 1100B having two segments may be one (1500B), and its coupling portion is on the two segments of the second stent body 1100B, respectively. can be located As described above, the front coupling part or the back coupling part of each anti-stretch wire 1500 may be located on the pull wire 1300 or the basket 1900 .

Here, the two coupling portions on the thrombus removal device 1000 to which each anti-stretching wire 1500 is connected may be disposed on a virtual straight line extending along one bridge 1123 and 1143, and each anti-stretching wire ( The radial position of 1500 may be determined according to the position of the bridges 1123 and 1143 between the two coupling parts.

Referring back to FIG. 32 , some of the plurality of anti-stretching wires 1500 may be designed to be positioned on the same line as the connection point between the stent body 1100 and the pull wire 1300 , and each length is two combinations It can be provided equal to the natural distance between parts. This effect may be described with reference to the above description.

When an external force is applied to the stent body 1100 during the shape deformation or recovery process of the thrombus removal device 1000, the length increase of the first stent body 1100A and the second stent body 1100B is the first anti-stretch wire 1500A ) and the second anti-stretch wire 1500B, and the length ratio of each is maintained similarly before and after the external force is applied, so that the thrombus removal device 1000 is in the first state or the second state. can be deformed to open and close the mouse structure.

Referring to Figure 33, the anti-stretching wire 1500 according to this example is a first anti-stretching wire 1500A and a second stent body 1100B to prevent an increase in the length of the first stent body 1100A. and a second anti-stretch wire 1500B to prevent it. Here, the first anti-stretching wire 1500A may be provided in the form of FIG. 24 , and the second anti-stretching wire 1500B may be provided in the form of FIG. 21 .

The first anti-stretching wire 1500A may be described with reference to the contents of FIG. 24 , and the second anti-stretching wire 1500B may be described with reference to the contents of FIG. 21 . As such, the anti-stretch wire 1500 provided to each stent body 1100 may include both a form in which two coupling parts are located in one segment and a shape in which two coupling parts are located in different segments, and accordingly, each The stretching wire 1500 may be disposed on the same line as the connection point of the stent body 1100 and the pull wire 1300 .

On the other hand, the first anti-stretching wire (1500A) and the second anti-stretching wire (1500B) are located in the same radial direction from the central axis of the stent body 1100, and the length is the same as the natural length between the two coupling parts. and the effect thereof may be described with reference to the above description.

When an external force is applied to the stent body 1100 during the shape deformation or recovery process of the thrombus removal device 1000, the length increase of the first stent body 1100A and the second stent body 1100B is the first anti-stretch wire 1500A ) and the second anti-stretch wire 1500B, and the length ratio of each is maintained similarly before and after the external force is applied, so that the thrombus removal device 1000 is in the first state or the second state. can be deformed to open and close the mouse structure.

Referring to FIG. 34 , the anti-stretching wire 1500 according to this example may be provided as a single strand connecting the first stent body 1100A and the second stent body 1100B. In detail, the anti-stretch wire 1500 is connected to the potential coupling portion is located in the second stent body (1100B), the rear coupling portion may be located in the first stent body (1100A). Through this, the anti-stretch wire 1500 may not cross the inner region of the second stent body 1100B by being located on the outside of the second stent body 1100B.

When the thrombus removal device 1000 in the first state is deployed in the blood vessel, the anti-stretch wire 1500 may be in a loose or twisted state. The anti-stretch wire 1500 in a loose state may be tightened according to the movement of the second stent body 1100B. By moving the second stent body 1100B until the anti-stretching wire 1500 is tense, the shape of the thrombus removal device 1000 may be transformed into the shape of the second state. Therefore, the anti-stretch wire 1500 of this example may perform a function of adjusting the positional relationship between the first stent body 1100A and the second stent body 1100B. The deformation of the thrombus removal device 1000 between the first state and the second state may be limited within a certain range according to the length of the anti-stretching wire 1500 .

Referring to FIG. 35 , the stent body 1100 of the thrombus removal device 1000 of this example is provided in a single segment form, and the first stent body 1100A and the second stent body 1100B have a distance along the longitudinal direction. can be placed

The first stent body (1100A) and the second stent body (1100B) are respectively connected to the first pull wire (1300A) and the second pull wire (1300B), the two pull wires (1300) by being operated independently of each other, the two stent bodies You can change the distance between (1100).

For example, as the second stent body 1100B moves by pulling the second pull wire 1300B and the distance between the two stent bodies 1100 is narrowed, the target thrombus is the first stent body 1100A and the second It may be sandwiched between the two stent bodies (1100B). Here, by pulling the second pull wire (1300B) more proximally or by combining the two pull wires (1300), the first stent body (1100A) and the second stent body (1100B) can be moved as one piece, the first stent The thrombus combined with the body 1100A and the second stent body 1100B may be recovered outside the body.

Hereinafter, the operation of the thrombus removal device 1000 of the present example will be described in detail.

When the thrombus removal device 1000 is deployed in the blood vessel, the target thrombus may be positioned between the first stent body 1100A and the second stent body 1100B. The first stent body 1100A and the second stent body 1100B may be located at a distance from each other. The distance between the first stent body 1100A and the second stent body 1100B may be greater than the size of the thrombus. The distance between the first stent body 1100A and the second stent body 1100B may be similar to the length of the mouse structure of the above-described embodiment. At this time, the first anti-stretch wire 1500A and the second anti-stretch wire 1500B may be in a stretched state.

According to the operation of the second pull wire (1300B), the second stent body (1100B) may move toward the first stent body (1100A). The distance between the first stent body 1100A and the second stent body 1100B may be close. Through this, the thrombus may be fixed between the first stent body 1100A and the second stent body 1100B. At this time, the second anti-stretch wire 1500B provided to the second stent body 1100B may be tightened according to the manipulation of the pull wire 1100B. The stretched second anti-stretch wire 1500B may prevent an increase in the length of the second stent body 1100B to limit the change in diameter of the second stent body 1100B within a certain range. Through this, it is possible to prevent the thrombus from leaving the second stent body 1100B.

In the process of recovering the thrombus removal device 1000 from the blood vessel, the first stent body 1100A and the second stent body 1100B may be simultaneously moved. This is by further pulling the second pull wire 1300B in a state in which the first stent body 1100A and the second stent body 1100B are close, or by combining the first pull wire 1300 and the second pull wire 1300B. It may be possible. When the thrombus removal device 1000 is withdrawn, the first anti-stretching wire 1500A provided to the first stent body 1100A and the second anti-stretching wire 1500B provided to the second stent body 1100B are pull wires ( 1300B) may be tightened according to the operation. The taut first anti-stretching wire 1500A and the second anti-stretching wire 1500B is the first stent body 1100A by limiting the deformation of the first stent body 1100A and the second stent body 1100B within a certain range. It is possible to prevent the thrombus located between the and the second stent body 1100B from being separated from the thrombus removal device 1000 .

In the above, a thrombus removal device including an anti-stretching mechanism in the form of an anti-stretching wire according to embodiments of the present specification has been described.

The anti-stretching mechanism does not have to be provided only in the form of an anti-stretching wire as described above, but may be provided in various other forms.

Hereinafter, a thrombus removal device including an anti-stretching strut or an anti-stretching mechanism in the form of an anti-stretching cell formed by an anti-stretching strut according to embodiments of the present specification will be described.

Here, the anti-stretch strut 1700 may be provided as a strut having a predetermined length formed inside the cell 1103 . In this case, the anti-stretch strut 1700 may be the same as or different from the strut forming the edge of the cell 1103 .

The anti-stretch strut 1700 may be provided as a strut having a predetermined length attached to at least two points of the rim of the cell. The anti-stretch strut 1700 can fix the distance between two points of the cell 1103 or prevent the distance between the two points from increasing more than a certain amount, thereby suppressing the deformation of the cell 1103 . As such, the cell 1103 in which deformation is suppressed by including the anti-stretching strut 1700 therein may be the anti-stretching cell 1703, and the cell structure to which the anti-stretching strut 1700 is attached is an anti-stretching cell structure (anti- stretching cell structure). When the increase in the length of the anti-stretch cell 1703 is suppressed by the anti-stretching strut 1700 or the anti-stretching cell structure, as a result, the length deformation of the stent body 1100, which is a mesh structure formed of the cells 1103, is suppressed and the stent A reduction in the diameter of the body 1100 or a shape deformation of the cell 1103 may be controlled.

FIG. 36 is a view of an example of a thrombus removal device according to yet another embodiment of the present specification, FIG. 37 is an exploded view of the thrombus removal device according to FIG. 36, and FIG. 38 is FIG. 36 It is a view of an example of an anti-stretching cell of a thrombus removal device according to the present invention.

36 and 37 , the stent body 1100 of the thrombus removal device 1000 may be provided as a mesh structure formed by struts including a plurality of cells 1103 . Here, the anti-stretching strut 1700 connected to at least two points of the edge of the cell 1103 of at least some of the cells 1103 included in the mesh structure may be connected. 36 and 37 respectively show three and four anti-stretching cells among all cells of the mesh structure, but the number of anti-stretching cells may be different therefrom.

The anti-stretch strut 1700 may be the same as the strut forming the mesh structure. Of course, it is also possible that the anti-stretch strut 1700 is different from the strut forming the mesh structure in material or diameter. For example, the anti-stretch strut 1700 may be made of a nickel titanium alloy or a material that restores a shape memorized at a high temperature when heated. In addition, the anti-stretch strut 1700 may include a material that provides visibility of the thrombus removal device 1000 during the thrombus removal process.

The anti-stretch strut 1700 may be connected to at least two points of the rim of the cell 1103 . The connection between the cell 1103 and the anti-stretch strut 1700 may be performed through a variety of methods.

For example, the anti-stretch strut 1700 may be integrally formed with the stent body 1100 while the stent body 1100 is formed. For example, when the stent body 1100 is manufactured by cutting a tube-shaped metal, the anti-stretch strut 1700 may be manufactured together as a part of the stent body 1100 .

As another example, the anti-stretch strut 1700 may be separately connected to the stent body 1100 . For example, the anti-stretch strut 1700 is mechanically locked to the edge of the cell of the stent body 1100, which is a completed three-dimensional mesh structure, welding, soldering (solder soldering), brazing ( It can be connected through brazing, brazing, adhesive, molding, or crimping. Mechanical locks may be connected through techniques such as twisting, knitting, webbing, meshing, or intertwining. For another example, the anti-stretch strut 1700 may be connected to the cell edge of the stent body 1100, which is a two-dimensional mesh structure of a stage before being completed as a three-dimensional mesh structure, through the above-described technique.

Control of the length deformation of the cell by the anti-stretch strut 1700 may be performed as follows.

Referring to FIG. 38 , the anti-stretch strut 1700 may include two connecting portions respectively connected to two points of the boundary of the cell 1103 and an extension portion extending from the two connecting portions. A point connected to two connecting portions of the anti-stretching strut 1700 among the edges of the cell 1103 may be referred to as a coupling portion.

In the description related to the anti-stretching wire, the connection part was used as a term referring to a part connected to the thrombus removal device of the anti-stretching wire, and the coupling part was used as a term referring to a part connected to the anti-stretching wire of the thrombus removal device, but the anti-stretch wire Even if the same terminology is used for an anti-stretching strut and an anti-stretching strut, it can be clearly distinguished from the context within the present specification, and the connecting portion is a thrombus removal device on the anti-stretching mechanism side, a stent body, a mesh structure or a cell connected to it. As a site, the coupling part can be comprehensively understood as a site connected to the anti-stretching mechanism on the thrombus removal device side that is connected to the anti-stretching mechanism. As a term referring to the site, the coupling part will be used as a term referring to the site connected to the anti-stretch strut of the cell.

Also, among the two coupling parts, a coupling part close to the proximal end of the thrombus removal device 1000 may be referred to as a potential coupling part, and a coupling part close to the distal end may be referred to as a coupling part, and a potential coupling part among the connection parts of the two anti-stretching struts 1700 . A connection portion corresponding to , is referred to as a front connection portion, and a connection portion corresponding to the rear connection portion is referred to as a rear connection portion. In addition, when the thrombus removal device 1000 is deployed under no-load or non-constrained conditions, the distance between the two coupling parts will be referred to as a natural distance between the two coupling parts.

When an external force is applied to the stent body 1100 , a lateral force in the longitudinal direction acts over the entire stent body 1100 , and accordingly, a tensile force along the longitudinal direction may also act on the cell 1103 . At this time, the anti-stretch strut 1700 may maintain a gap between the connection part and the two coupling parts connected to the connection part by resisting the tensile force. Accordingly, length deformation of the cell 1103 can be prevented.

For example, as shown in FIG. 38 , when a tensile force in the longitudinal direction is applied to the cell 1103 as a recovery force is applied to the stent body 1100 , the cell 1103 without the anti-stretch strut 1700 has a length increases and the width decreases. This may result in an increase in the length of the entire stent body 1100 and a decrease in diameter.

At this time, as illustrated in FIG. 38, when anti-stretching struts 1700 having the same length as the length of the cell 1103 in the unfolded state of the no-load state are connected to both corners in the longitudinal direction of the cell 1103, Even when a tensile force is applied to the cell 1103 , the anti-stretch strut 1700 may maintain the shape of the cell. When the shape of the cell is maintained, the deformation of the stent body 1100 as a whole can be controlled.

Meanwhile, the above-described corner of the cell 1103 may refer to a predetermined area near a point connected to another adjacent cell 1103 among the edges of the cell 1103 . In this case, the corner and the corner The edge of the cell 1103 extending therebetween may be referred to as an edge. In addition, two adjacent cells 1103 connected through a 'corner' refer to one cell 1103 and an adjacent cell 1103 along a column or row of the stent body therefrom. Referring to FIG. 37, one Cells 1103 disposed along the longitudinal direction of the stent body 1100 from the cells 1103 of , or cells 1103 disposed in a vertical direction therewith may be adjacent cells 1103 connected through corners.

Here, if all cells 1103 forming the mesh structure are provided as anti-stretching cells 1703, the increase in length of the stent body 1100 can be completely prevented, and only some cells 1103 are anti-stretching cells 1703. In the case of providing the anti-stretch cell 1703 due to the length deformation occurring in the cells 1103 other than the stent body 1100, the length deformation is allowed only up to a certain level, and further length deformation can be suppressed. .

On the other hand, unlike the above-described anti-stretching wire, the anti-stretching mechanism provided as an anti-stretching strut can suppress a decrease in length as well as an increase in length. Again, as shown in FIG. 38 , when anti-stretching struts 1700 having the same length as the length of the cell 1103 in the deployed state in the unloaded state are connected to both corners in the longitudinal direction of the cell 1103, the cell 1103 ) by the anti-stretching strut 1700 maintaining the length of both corners even if a compressive force along the longitudinal direction is applied, the reduction in the length of the cell can be suppressed.

In the description with reference to FIG. 38, the anti-stretch strut 1700 is installed in the cell 1103 through both corners along the longitudinal direction of the diamond-shaped cell 1103, and the stent body 1100 is in a deployed state under no-load condition. When it has been described as having the same length as the distance between the corners of the cell 1103, this is only an example, and the connection point between the anti-stretching strut 1700 and the cell 1103 or the length of the anti-stretching strut 1700 can be variously changed.

FIG. 39 is a view of another example of an anti-stretching cell of the thrombus removal device according to FIG. 36 .

The position of the coupling portion on the edge of the cell 1103 connected to the anti-stretch strut 1700 may vary, and examples thereof are shown in FIG. 39 .

Here, the anti-stretch strut 1700 has a characteristic to maintain a gap between the two coupling portions, and since the deformation of the stent body 1100 is mainly caused by a lateral tensile force in the recovery process, the two coupling portions are the cell 1103 Among the edges, it may be preferable to be disposed at a location spaced apart from each other by a predetermined distance or more in the longitudinal direction of the stent body 1100 . For example, the coupling portion may be disposed at both corners in the longitudinal direction where the distance between the coupling portions is maximized for the diamond-shaped cell 1103 as shown in FIG. 39 .

Also, here, in order for the anti-stretching strut 1700 to resist the tensile or compressive force in the transverse direction, it is advantageous if the ratio of the component along the longitudinal direction of the stent body 1100 among the resistance forces acting on the anti-stretching strut 1700 is high. As for the positional relationship between the two coupling parts, it may be preferable that an imaginary straight line connecting the two coupling parts forms a predetermined angle or less with the longitudinal direction of the stent body 1100 . For example, an imaginary straight line connecting the two coupling parts may be the same as the longitudinal direction of the stent body 1100 as shown in FIG. 39 . For another example, the coupling portion may preferably form an angle of at least 45 degrees or less with the length direction of the stent body 1100 in a virtual straight line connecting the two coupling portions.

However, if you want to prevent the diameter deformation of the stent body 1100 rather than the length deformation of the stent body 1100 through the anti-stretch strut 1700, a virtual straight line connecting the two coupling portions is rather a stent body 1100. It may be desirable to form an angle of at least 45 degrees or more with the longitudinal direction of

On the other hand, in order to prevent the cell 1103 from being distorted by the resistance force of the anti-stretching strut 1700 acting asymmetrically within the cell 1103 , the two coupling portions of the anti-stretching strut 1700 are among the corners of the cell 1103 . It may be desirable to be disposed at a point symmetrical position or a line symmetrical position with respect to the center of the cell 1103 .

In addition, it is obvious that the anti-stretch strut 1700 is not necessarily applied only to the diamond-shaped cells, and may be applied to all of the various types of cells.

The length of the anti-stretch strut 1700 may also be determined in various ways, and examples thereof are shown in FIG. 39 .

According to one example, the length of the anti-stretch strut 1700 may be substantially equal to the natural distance between the coupling portions. The anti-stretch strut 1700 having a length equal to the natural distance between the coupling portions can prevent the cell 1103 from being deformed in length.

According to another example, the length of the anti-stretch strut 1700 may be greater than the natural distance between the coupling portions. The anti-stretching strut 1700 having a length greater than the natural distance between the coupling portions allows the length deformation of the cell 1103 to a certain level, but can prevent further length deformation. Specifically, the anti-stretch strut 1700 is from a state in which the distance between the coupling parts is smaller than the length of the anti-stretch strut 1700 to a state in which the distance between the coupling parts is equal to the length of the anti-stretch strut 1700 of the cell 1103. Allowing length deformation, and when the distance between the coupling portions is equal to the length of the anti-stretching strut 1700, it is possible to prevent the length from increasing beyond that.

Meanwhile, although it has been described above that one anti-stretching strut is positioned in the anti-stretching cell, the number of anti-stretching struts may be plural if necessary. The plurality of anti-stretching struts may have the same or different coupling portions, and may also have the same or different lengths.

At least one anti-stretch cell 1703 formed by the above-described anti-stretch strut 1700 may be included in the stent body 1100 . As the number of anti-stretch cells 1703 increases, the length deformation of the stent body 1100 and its diameter deformation and shape deformation can be suppressed, and the flexibility of the stent body 1100 can be reduced, so the number of anti-stretch cells needs to be properly designed.

When a plurality of anti-stretching cells are included in the mesh structure as shown in FIG. 37, the arrangement of the anti-stretching cells may vary.

As an example, the anti-stretch cell may be arranged in consideration of a covering ratio. Here, the covering ratio may mean a ratio of the area (ie, the covering area) to which the anti-stretching effect by the anti-stretching cell 1703 is applied among the entire area of the stent body 1100 . Preferably, the anti-stretching cell 1703 may be arranged so that the covering ratio by the anti-stretching cell 1703 is 30% to 100%. For example, among all the cells 1103 of the mesh structure, a row of cells 1103 continuous in the longitudinal direction from the proximal end to the distal end of the stent body 1100, all cells 1103 belonging to the same row, or One cell for each column may be provided as the anti-stretching cell 1703, and in this case, the covering ratio may be 100%. For another example, a column to which the anti-stretching cell 1703 belongs and a column having only normal cells (non-anti-stretching cells) are alternately arranged, and the covering ratio at this time may be 50%. Alternatively, only normal cells are arranged in two consecutive rows, and anti-stretching cells 1703 may be arranged in the stent body 1100 in a form that repeats the pattern in which the anti-stretching cells 1703 are arranged in the next column, In this case, the ratio of the number of columns having the anti-stretching cells 1703 to the total number of columns may be the covering ratio. However, in order to suppress an increase in the length of the stent body 1100 and at the same time ensure the compressibility and flexibility of the stent body 1100, the covering ratio may be preferably determined to be 50 to 80%.

In the above description, 'row' means a position to which cells continuous in the longitudinal direction of the stent body 1100 belong when the stent body 1100 is viewed in a two-dimensional development view, and also in the longitudinal direction in the three-dimensional mesh structure. It may mean a position to which consecutive cells belong. Similarly, when the 'column' is viewed in a two-dimensional development view of the stent body 1100, it means a position to which cells continuous in the vertical direction of the longitudinal direction of the stent body 1100 belong, and on the three-dimensional mesh structure, the circumference direction can be matched. Here, when a straight line connecting consecutive cells forms an angle with the longitudinal direction of the stent body 1100, if the component in the vertical direction is greater than the component in the longitudinal direction of the straight line connecting the cells, the corresponding cell is located along the column can be considered to be

On the other hand, so that the anti-stretching effect occurs equally in the longitudinal direction of the stent body 1100, the anti-stretching cells 1703 are spaced apart between the anti-stretching cells 1703 in the longitudinal direction as far as possible, or the spacing between the anti-stretching cells 1703 This may be arranged to be constant. In other words, the anti-stretching cells 1703 may be arranged such that the intervals between the columns to which the anti-stretching cells 1703 belong are relatively uniform. For example, when you want to arrange 6 anti-stretch cells 1703 in the stent body 1100 having 12 columns, the anti-stretch cells 1703 are odd number of 12 columns?? Alternatively, it may be placed in an even-numbered column.

In addition, so that the anti-stretching effect occurs equally in the radial direction of the stent body 1100, the anti-stretching cells 1703 are arranged so that the angles formed from each other on the longitudinal cross-section of the stent body 1100 are spaced apart as much as possible or the angles formed from each other are constant. have. In other words, the anti-stretching cells 1703 may be arranged such that the spacing between the rows to which the anti-stretching cells belong is relatively uniform. For example, when you want to arrange three anti-stretching cells 1703 in the stent body 1100, the anti-stretching cells 1703 are the central axis of the stent body 1100 so that the anti-stretching cells 1703 are spaced apart from each other as much as possible. They may be disposed to form an angle of 120 degrees with respect to each other. For another example, when you want to arrange 12 anti-stretching cells 1703 in the stent body 1100, any three anti-stretching cells 1703 are arranged so that the spacing between the anti-stretching cells 1703 is constant with each other in the radial direction. Based on the specific direction arranged on the other three anti-stretching cells 1703 are arranged at an angle of 90 degrees with respect to the specific direction, and the other three anti-stretching cells 1703 are arranged to form 180 degrees with respect to the specific direction. Then, another three anti-stretch cells 1703 may be arranged to form a 270 degree with respect to a specific direction.

On the other hand, as described above, at least two anti-stretching cells 1703 among the plurality of anti-stretching cells 1703 are arranged in the same direction in the radial direction, anti-stretching cells 1703 arranged in the same direction in the radial direction. may be preferably arranged such that the spacing between them is maximized. Specifically, 12 anti-stretching cells 1703 are again described based on the above-described example arranged to form a 90 degree angle with each other, the 12 anti-stretching cells 1703 are arranged at 1/12 intervals of the total length in the longitudinal direction. In this case, the first cell at the front in the longitudinal direction is in a specific direction in the radial direction, the second cell is at an angle of 90 degrees to the specific direction, and the third cell is 180 degrees to the specific direction in the radial direction and the fourth cell is at an angle of 180 degrees to the specific direction in the radial direction. The cells may be arranged at 270 degrees with respect to a specific direction in the radial direction, and the above pattern from the 5th cell to the 12th cell may be repeatedly arranged. As such, by disposing the anti-stretching cells 1703 in consideration of the spacing in the longitudinal direction and the spacing in the radial direction, the anti-stretching effect by the anti-stretching cells 1703 is dispersed throughout the stent body 1100 and can act equally.

Hereinafter, examples of the thrombus removal device according to the present embodiment having an anti-stretching mechanism in the form of an anti-stretching strut will be described.

On the other hand, prior to explaining the example of the thrombus removal device, the stent body of the thrombus removal device according to FIGS. 40 and 44 includes at least one type of cell, and at least one anti-stretching cell is provided for each column of the stent body. Although it shows that the covering ratio is 100%, the covering ratio by the anti-stretching cell may have various values, and when the covering ratio is 100% or less, the anti-stretching cell 1703 is not disposed of the stent body 1100 of It is stated in advance that the length section can be deformed by an external force.

In addition, unlike shown in FIGS. 40 to 44, the shape of the anti-stretching strut 1700 in the anti-stretching cell 1703 can be designed in various ways, and the anti-stretching effect of the anti-stretching cell is may increase or decrease.

On the other hand, the thickness of the anti-stretching strut 1700 of FIGS. 40 to 44 is shown to be thinner than the thickness of the strut 1101 of the stent body 1100, but this is to emphasize the arrangement of the anti-stretching strut 1700. , the thickness of the anti-stretch struts 1700 may be provided similarly to the thickness of the struts 1101, unlike those shown, or may be provided thicker than that.

40 is a view of another example of a thrombus removal device according to another embodiment of the present specification, and FIG. 41 is an exploded view of the thrombus removal device according to FIG. 40 .

Referring to FIGS. 40 and 41 , the anti-stretching cells 1703 according to the present example are provided one for each column of the stent body 1100, thereby continuously positioned along the longitudinal direction of the stent body 1100, and the stent body 1100. By being arranged along the row of the stent body 1100 may be all located in the same direction from the central axis.

Here, the anti-stretching struts 1700 provided in each anti-stretching cell 1703 may be connected to both corners in the longitudinal direction of the cell 1103, and may be formed parallel to the longitudinal direction of the stent body 1100, and , the length of the anti-stretch strut 1700 may be provided equal to the distance between the two coupling portions to which the anti-stretch strut 1700 is connected.

At this time, the rear connection portion of the anti-stretch strut 1700 located relatively proximal among the adjacent anti-stretch struts 1700 may be located adjacent to the front connection portion of the anti-stretch strut 1700 located relatively distally, and a plurality of The anti-stretch struts 1700 may be located on the same straight line.

When the anti-stretch cell 1703 is disposed in the form shown in FIGS. 40 and 41 , the increase/decrease in its length can be suppressed with respect to the entire stent body 1100 , and in detail, the lateral force is applied to the stent body 1100 . When the shape deformation of each anti-stretching cell 1703 is suppressed, the length deformation of each row of the stent body 1100 in which the anti-stretching cell 1703 is located can be limited, through which the stent body after the lateral force is applied. The length of 1100 may remain similar to the length before the lateral force is applied.

42 is a view of another example of a thrombus removal device according to another embodiment of the present specification, and FIG. 43 is an exploded view of the thrombus removal device according to FIG. 42 .

42 and 43, anti-stretch cells 1703 according to the present example are provided one in each column of the stent body 1100, but radially by being spaced apart at a 90 degree angle with respect to the central axis of the stent body 1100. may be arranged differently.

Here, the shape of the anti-stretching strut 1700 provided in each anti-stretching cell 1703 is the same as that shown in FIGS. 40 and 41 , and each anti-stretching cell 1703 is separated from the central axis of the stent body 1100 . By being disposed in different radial directions, the rear connection portion of the anti-stretching strut 1700 located relatively proximal among the adjacent anti-stretching struts 1700 may be spaced apart from the potential connection portion of the anti-stretching strut 1700 located relatively distally. have.

Anti-stretching cells 1703 provided in each column of the stent body 1100 can prevent an increase in the length of the stent body 1100 by suppressing its shape deformation, and anti-stretching cells 1703 as shown in FIGS. 42 and 43. When arranged to form a constant angle with respect to the central axis of the stent body 1100, the anti-stretching effect by the anti-stretching cell 1703 can occur evenly in the radial direction of the stent body (1100).

44 is a view of another example of a thrombus removal device according to another embodiment of the present specification.

Referring to FIG. 44 , the anti-stretching cells 1703 according to this example are provided in each row of the stent body 1100 by two, thereby continuously positioned along the longitudinal direction of the stent body 1100, and two anti-stretching cells provided in each row. The stretching cells 1703 may be disposed along two rows of the stent body 1100 and positioned symmetrically with respect to the central axis of the stent body 1100 .

When two anti-stretching cells 1703 are arranged in each column of the stent body 1100, the effect of resisting length deformation can be stronger than when one anti-stretching cell 1703 is arranged, and the two anti-stretching cells 1703 ) by being symmetrically disposed with respect to the central axis of the stent body 1100, the stretching prevention effect can occur equally.

In the above, an example in which the thrombus removal device has the shape of only one cell has been described, but the shape of the cell of the stent body does not have to be a single shape.

45 is a view of yet another example of a thrombus removal device according to another embodiment of the present specification, FIG. 46 is a preview of a development view of the thrombus removal device according to FIG. 45, and FIG. Another example of a developed view of the thrombus removal device according to FIG. 48 is a view related to the thrombus removal device according to FIG. 47 , and FIG. 49 is another example of a development view of the thrombus removal device according to FIG. 45 .

Referring to FIG. 45 , the stent body 1100 may include two types of cells 1103 . The two types of cells may include a first cell 1104 and a second cell 1105 . Since the stent body 1100 includes two types of cells, it is possible to control the degree of deformation of the stent body 1100 by an external force.

45 , the stent body 1100 may alternately include a row in which a first cell 1104 is disposed and a row in which a second cell 1105 is disposed, through which the first cell 1104 is disposed. ) and the second cell 1105 may be disposed along a spiral extending along the circumference of the stent body 1100 . In addition, the angle formed by the imaginary straight line connecting the first cells 1104 arranged along the spiral with respect to the central axis of the stent body 1100 may be less than 90 degrees.

Since the degree of deformation of the stent body 1100 by an external force may appear differently depending on the size, shape or arrangement of the cell 1103, the stent body 1100 as shown in FIG. 45 includes two types of cells 1103. An increase in the length of the stent body 1100 may vary during the recovery process of the thrombus removal device 1000 .

Referring to FIG. 46 , the anti-stretching struts 1700 may be provided in the first cell 1104 , and the arrangement of the anti-stretching cells 1703 as illustrated in FIG. 46 is illustratively similar to FIG. 41 . can be provided. In other words, the anti-stretch cell 1703 may be disposed on a straight line parallel to the longitudinal direction of the stent body 1100 .

As shown in Figure 46, the first cell 1104 is arranged continuously along the longitudinal direction of the stent body 1100 to constitute a row of the stent body 1100, the first cell 1104 arranged in each row may be located on a spiral extending along the circumference of the stent body 1100 . At this time, in the deployed stent body 1100, an angle between the imaginary straight line connecting the first cells 1104 disposed on the spiral and the longitudinal direction of the stent body 1100 may be less than 90 degrees, and thus The section in which the length change is suppressed by each anti-stretching cell 1703 may be a distance section from the proximal end to the distal end of each anti-stretching cell 1703 .

Also referring to FIG. 47 , unlike the above description, the anti-stretching strut 1700 may be provided in the first cell 1104 , and the arrangement of the anti-stretching cell 1703 may be provided in the form of FIG. 42 . In other words, the anti-stretch cells 1703 are continuously located along the longitudinal direction of the stent body 1100, and the anti-stretch cells 1703 in each row are at an angle of 90 degrees to each other with respect to the central axis of the stent body 1100. It can be arranged to achieve

As shown in FIG. 47 , the row in which the first cell 1104 is disposed may be alternately positioned with the row in which the second cell 1105 is disposed. may be located spaced apart by a distance of . Since the positions of the first cells 1104 arranged in different rows are spaced apart in the longitudinal direction, the anti-stretching cells 1703 provided in different rows may be arranged at a predetermined distance in the longitudinal direction.

Compared with the anti-stretching cell 1703 according to FIG. 46 described above, the anti-stretching cell 1703 according to FIG. 47 has the same number, but by being spaced apart in the longitudinal direction of the stent body, the stretching prevention effect is increased in the longitudinal direction. can occur equally. In addition, since the anti-stretching cell 1703 of FIG. 47 is arranged in different directions from the central axis of the stent body 1100, the anti-stretching effect thereof can occur equally in the radial direction.

Referring to FIG. 49 , two anti-stretch cells 1703 may be disposed in a row or column of the stent body 1100 . A plurality of anti-stretching cells 1703 according to FIG. 49 are arranged at regular intervals in the longitudinal direction and in the radial direction, through which the anti-stretching effect by the anti-stretching cells 1703 is equally applied to the stent body 1100. can work

On the other hand, the number of anti-stretching cells 1703 provided in the thrombus removal device 1000 of FIG. 49 may be twice the number of anti-stretching cells 1703 of FIG. The effect of preventing stretching may be increased as compared with FIG. 47 . In addition, since the two anti-stretch cells 1703 act in a specific length section of the stent body 1100, the anti-stretch effect may appear stronger for a specific length section.

In the above, the anti-stretch cell has been described with reference to a thrombus removal device having a single-segment type single-stent body. can be

50 to 58 are views of various examples of a thrombus removal device according to another embodiment of the present specification.

Referring to FIGS. 50 and 51 , the stent body 1100 of the thrombus removal device 1000 may include a segment and a mouse structure, thereby capturing randomly located ligament thrombus or menstrual thrombus. Here, the anti-stretching mechanism of the thrombus removal device 1000 according to an embodiment may be provided as an anti-stretching strut 1700 in the form of a strut.

At this time, the thrombus removal device 1000 prevents the stent body 1100 from excessively reducing the diameter size of the stent body 1100 through the anti-stretch strut 1700 so that the stent body 1100 engages the thrombus to capture the thrombus. . In addition, the thrombus removal device 1000 of this embodiment can maintain a length ratio of one segment to another segment within a certain range during the thrombus removal process through the anti-stretch strut 1700, and the mouse structure of the stent body 1100 The size and shape can be maintained similar to the size and shape of the mouse structure in a no-load state.

Referring again to FIGS. 50 and 51 , anti-stretching struts 1700 may be provided in cells 1103 of each segment of stent body 1100 . Anti-stretch cells 1703 are located in various radial directions with respect to the central axis of the longitudinal direction of the stent body 1100, may be sequentially arranged along the longitudinal direction. Through this, a change in the length of each segment of the stent body 1100 can be suppressed, and deformation of the cells 1103 located in various directions from the center of the stent body 1100 can be prevented.

Here, the stent body 1100 of the thrombus removal device 1000 may further include a segment and a mouse structure. At this time, the anti-stretch cell 1703 may be provided in each segment to prevent deformation of the segment.

The shape of the anti-stretching strut 1700 provided in the segment and the arrangement of the anti-stretching cell 1703 may refer to the above-described example, but should not be limited to the above-described example, and may include various examples not mentioned.

Referring to FIGS. 52 and 53 , the thrombus removal device 1000 prevents excessive reduction in diameters of the first stent body 1100A and the second stent body 1100B through the anti-stretching cell 1703, thereby preventing thrombus. It can prevent the escape of blood and blood clots. In addition, the thrombus removal device 1000 of this embodiment may maintain a length ratio of the second stent body 1100B to the first stent body 1100A within a certain range during the thrombus removal process through the anti-stretch strut 1700 . Through this, the thrombus removal device 1000 may be deformed between the shape of the first state and the shape of the second state.

Anti-stretch struts 1700 may be provided in cells 1103 of each segment of first stent body 1100A and second stent body 1100B. Anti-stretch cell 1703 is located in various radial directions with respect to the central axis of the longitudinal direction of the first stent body 1100A and the second stent body 1100B, may be sequentially arranged along the longitudinal direction. Detailed information on this may be described with reference to the foregoing.

On the other hand, in the thrombus removal device 1000 whose shape is deformed to a first state or a second state according to the relative positional relationship of the two stent bodies 1100, interference between the two stent bodies 1100 is prevented or the second The radial position of the anti-stretching cell 1703 provided to the stent body 1100 may be determined so that the segments of the two stent bodies 1100 overlapping each other in the state have the same shape, which will be described with reference to the above can

On the other hand, the anti-stretching cell 1703 may be arranged in a different form than shown, and the form of the anti-stretching strut 1700 and the arrangement of the anti-stretching cell 1703 may refer to the above-described example, but the above-described one It should not be limited to the example of , and may include various examples not mentioned.

54 to 56 , the thrombus removal device 1000 is generally similar to the thrombus removal device 1000 of FIGS. 52 to 53 , but has a partially different shape.

As an example, in the stent body 1100 of the thrombus removal device 1000 of FIGS. 52 and 53 , the bridge of the mouse structure is connected to the proximal end of the relatively distal segment among the two adjacent segments, but in FIGS. 54 to 56 . In the stent body 1100 of the thrombus removal device 1000, the bridge of the mouse structure is connected to a predetermined position distal to the proximal end of the distal segment among the two adjacent segments.

As another example, in the process of the thrombus removal device 1000 going back and forth between the first state and the second state, the positions of the first stent body 1100A and the second stent body 1100B with respect to each other may be changed, at this time Mechanical interference may occur between the first stent body 1100A and the second stent body 1100B. For example, while the thrombus removal device 1000 is deformed from the first state to the second state, the first segment 1110 and the second segment 1130 of the first stent body 1100A are distal The distal end may interfere with the proximal end of the fifth segment 1110B and the sixth segment 1130B of the second stent body 1100B. In order to prevent a case in which deformation of the thrombus removal device 1000 is limited due to interference, the distal ends of the first segment 1110 and the second segment 1130 of the first stent body 1100A are provided in a protruding form. Also, the proximal ends of the fifth segment 1110B and the sixth segment 1130B of the second stent body 1100B may not be provided in a protruding form. As such, the shape for preventing mechanical interference between the first stent body 1100A and the second stent body 1100B may be referred to as an interference reduction mechanism.

Meanwhile, the anti-stretch strut 1700 of FIGS. 54 to 56 may be provided in the cell 1103 of each segment of the first stent body 1100A and the second stent body 1100B. The anti-stretching cell 1703 of FIGS. 56 and 58 may be provided in the form of FIG. 46 . Anti-stretch cell 1703 is located in various radial directions with respect to the longitudinal central axis of the first stent body 1100A and the second stent body 1100B, and may be sequentially disposed along the longitudinal direction, but it is not necessarily No, it is obvious that the above-described examples or various examples not mentioned may be provided.

57 and 58 , the anti-stretching mechanism of the device of the thrombus removal device may be provided as an anti-stretching rail 1790 in the form of a rail.

Here, the anti-stretch rail 1790 is a strut formed on the circumferential surface of the stent body 1100 of the thrombus removal device 1000 , and may limit deformation in the longitudinal direction of the stent body 1100 . Through this, the lengthening of the stent body 1100 is prevented/reduced, and accordingly, the size reduction of the diameter of the stent body 1100 or the shape deformation of the cell 1103 can be prevented/reduced.

The anti-stretch rail 1790 may extend along one direction on the circumferential surface of the stent body 1100, thereby connecting at least two cells 1103 disposed along the one direction, through which one cell 1103 And cells 1103 adjacent thereto may be spaced apart from each other in the longitudinal direction of the stent body 1100 . As such, the anti-stretch rail 1790 connects one cell 1103 and another cell 1103, thereby preventing the distance between the cells 1103 from moving away from or getting closer beyond a certain range, and the stent body ( 1100) may limit deformation in the longitudinal direction.

Here, since the two adjacent cells 1103 are not connected through each other's proximal or distal ends, the adjacent two cells 1103 are spaced apart from each other along the longitudinal direction of the stent body 1100 and are located in each cell 1103. The proximal end or the distal end may be free from radial deformation of the stent body 1100 . The distal end or the proximal end of the two adjacent cells 1103 may be free to deform radially from the longitudinal central axis of the stent body 1100, and may be bent toward the inside or outside of the stent body 1100 .

The anti-stretch rail 1790 may be formed differently according to a manufacturing method of the stent body 1100 . As an example, the anti-stretch rail 1790 may be manufactured together as a part of the stent body 1100 . As another example, the anti-stretch rail 1790 may be additionally connected to the independently manufactured stent body 1100 . As another example, the anti-stretch rail 1790 may form the stent body 1103 by connecting the independently manufactured cells 1103 .

Here, the cell 1103 may be provided in an asymmetrical shape, and both end portions of the cell 1103 may have a curved shape having different curvatures. When defining a first region including the distal end of the cell 1103 and a second region including the proximal end of the cell 1103 with reference to the minor axis of the cell 1103 , the curvature of the first region may be greater than the curvature of the second region. and the first region may have a longer shape than the second region.

At this time, the first region of the cell 1103 may be flared in a radially outward direction from the central axis of the stent body 1100 through thermoforming, through which an external force is applied to the stent body 1100 so that its diameter is Even when collapsed, the flared cell 1103 can remain in contact with the vessel wall.

Hereinafter, examples of a thrombus removal method according to an embodiment of the present specification will be described.

An example of the thrombus removal method according to the embodiment of the present specification may be a thrombus removal method using a thrombus removal device having a single stent body among the examples of the thrombus removal device described above. This example will be described with reference to FIG. 59 .

59 is a flowchart of an example of a thrombus removal method according to an embodiment of the present specification.

Referring to FIG. 59 , a method ( S1000 ) of removing a thrombus according to an embodiment of the present specification is as follows.

A method for removing a thrombus according to an embodiment includes: inserting a thrombus removal device in a compressed state into a blood vessel (S1100); Expanding the thrombus removal device in a compressed state in the blood vessel (S1200); The thrombus removal device is deployed in the blood vessel (S1300); Step (S1400) of receiving an external force applied to the thrombus removal device; and the anti-stretching mechanism preventing the thrombus removal device from being deformed in length (S1500).

Hereinafter, each step will be described in more detail.

The thrombus removal device 1000 may be inserted into a blood vessel (S1100).

When a location of a thrombus that obstructs the flow of blood in a patient's blood vessel is detected, the guide wire is moved to the corresponding location, and then a catheter may be inserted into the blood vessel along the guide wire. When the inserted catheter reaches a procedure point near the thrombus, the thrombus removal device 1000 may be delivered through the hollow of the catheter after the guide wire is removed. At this time, the thrombus removal device 1000 is compressed by the catheter, and may be disposed adjacent to the target thrombus through the catheter.

The thrombus removal device 1000 may expand in the blood vessel ( S1100 ).

When the catheter is recovered after the thrombus removal device 1000 in a compressed state is placed close to the target thrombus, the stent body 1100 of the thrombus removal device 1000, which is an elastic body, has the restoring force of the elastic body as the external force by the catheter is removed. can expand by itself. The stent body 1100 may expand until its diameter is similar to the diameter of the blood vessel, and during the expansion process, the stent body 1100 of the thrombus removal device 1000 may combine with a thrombus.

The thrombus removal device 1000 may be deployed in a blood vessel (S1300).

The stent body 1100 of the thrombus removal device 1000 deployed in the blood vessel may have a hollow shape. The stent body 1000 can accommodate the thrombus that has entered the interior of the stent body 1100 through between the struts 1101, the inside of the cell 1103 or the mouse structure, and the like, and the stent body 1100 is inside the stent body 1100. By accommodating the thrombus in the space, the thrombus removal device 1000 may capture the thrombus. The thrombus removal device 1000 deployed in this way may carry a thrombus coupled to the stent body 1100 or a thrombus captured inside the stent body 1100 .

The thrombus removal device 1000 may receive an external force (S1400).

An external force may be applied to the thrombus removal device 1000 to remove the thrombus by recovering the thrombus removal device 1000 carrying the thrombus outside the body, and specifically, the stent body 1100 through manipulation of the pull wire 1300 . ) can be applied with an external force.

For example, when the pull wire 1300 is manipulated in the process of recovering the thrombus removal device 1000 , the stent body 1100 has a recovery force acting in the proximal direction by the pull wire 1300 and the stent body 1100 . The resistance force acting in the distal direction may act due to the adhesion between the blood vessel and the weight of the thrombus. For another example, in the process of recovering the thrombus removal device 1000 , the stent body 1100 may pass through a curved section of the blood vessel, and an external force is applied to a part of the stent body 1100 , so that the stent body 1100 . Some of it may be excessively deformed.

The anti-stretching mechanism may prevent the length of the thrombus removal device from being deformed (S1500).

The anti-stretching mechanism may prevent the length of the stent body 1100 from being excessively deformed when an external force is applied to the stent body 1100 of the thrombus removal device 1000 .

As an example, the anti-stretching mechanism may be provided as an anti-stretching wire 1500 . The anti-stretching wire 1500 prevents the length deformation of the stent body 1100 by limiting the distance between the two coupling portions of the thrombus removal device 1000 to which the anti-stretching wire 1500 is connected to within the length of the anti-stretching wire 1500 . can do. For example, if the length of the anti-stretch wire 1500 is equal to the distance between the two coupling portions, the distance between the two coupling portions may be maintained substantially equal to the natural distance.

As another example, if the length of the anti-stretching wire 1500 has a value greater than the distance between the two coupling portions, the distance between the two coupling portions increases until the loose anti-stretching wire 1500 is taut, and the increase in length is It may be limited within the length of the stretching wire 1500 . The operation of the anti-stretching wire 1500 is not limited to the above, and should be interpreted including the various examples described above.

In addition, an anti-stretching mechanism may be provided as an anti-stretching strut 1700 . The anti-stretch strut 1700 can prevent the cell 1103 from being excessively stretched or excessively shortened than its natural length by suppressing the shape deformation of the cell 1103 . For example, when an external force is applied to the stent body 1100, the length section of the stent body 1100 in which the anti-stretching cell 1703 is located is maintained similarly to the shape of the anti-stretching cell 1703 during initial deployment. The length deformation may be limited, and thus the deformation of the overall stent body 1100 may be limited. The operation of the anti-stretch strut 1700 is not limited to the above, and should be interpreted including the various examples described above.

On the other hand, in the embodiment of the present specification, the anti-stretching mechanism having the form of the anti-stretching wire 1500 or the anti-stretching strut 1700 has been mainly described, but the anti-stretching mechanism is not limited to the above-described example, and various unmentioned It can be implemented in the form

Since the anti-stretching mechanism is provided in the thrombus removal device 1000 , the thrombus removal device 1000 may easily bind to or capture the thrombus, and will not miss the thrombus until the thrombus removal device 1000 is recovered from the body. can be held without In detail, the anti-stretching mechanism suppresses the increase in the length of the stent body 1100 to maintain the diameter size within a certain range, and by limiting the shape deformation of the cell, the function of the thrombus removal device 1000 can be fully exhibited, and capture Fragmentation of the thrombus is prevented, and the thrombus leakage to the outside of the stent body 1100 can be prevented. In addition, when the thrombus removal device 1000 includes the multi-segment stent body 1000, the anti-stretch mechanism prevents the diameter reduction of each segment so that the size and shape of the mouse structure is the size and shape of the mouse structure under no-load conditions. may be maintained similarly to , and thereby, the success rate of thrombus capture of the thrombus removal device 1000 may be improved.

Another example of the thrombus removal method according to the embodiment of the present specification may be a thrombus removal method using a thrombus removal device having a dual stent body among the examples of the thrombus removal device described above. This example will be described with reference to FIG. 60 .

60 is a flowchart of another example of a thrombus removal method according to an embodiment of the present specification.

Referring to FIG. 60 , an example of a method for removing a thrombus includes: inserting a thrombus removal device in a compressed state into a blood vessel (S2100); Expanding the thrombus removal device in a compressed state in a deployed state in the blood vessel (S2200); Step (S2300) in which the thrombus removal device is in a first state; transforming the thrombus removal device in the first state into the thrombus removal device in the second state (S2400); Step (S2500) in which the thrombus removal device is in a second state; Step (S2600) receiving an external force applied to the thrombus removal device; and the anti-stretching mechanism preventing the thrombus removal device from being deformed in length (S2700).

Hereinafter, each step will be described in more detail.

The step of inserting the thrombus removal device in a compressed state into the blood vessel (S2100) and the step of expanding the thrombus removal device in the compressed state into a deployed state in the blood vessel (S2200) may be described with reference to S1100 and S1200 described above. have.

The thrombus removal device 1000 may be in a first state ( S2300 ). When the thrombus removal device 1000 is in the first state, a segment of the second stent body 1100B may correspond to a mouse structure of the first stent body 1100A. The segments of the first stent body 1100A and the segments of the second stent body 1100B may be alternately positioned along the longitudinal direction of the thrombus removal device 1000 to contact the blood vessel wall. The thrombus removal device 1000 may be coupled to an intravascular thrombus through a segment of the first stent body 1100A and a segment of the second stent body 1100B. The thrombus removal device 1000 may accommodate the thrombus in the first stent body 1100A and the second stent body 1100B.

The thrombus removal device 1000 may be deformed from the first state to the second state by manipulation of the first pull wire 1300A or the second pull wire 1300B (S2400). For example, by manipulating the second pull wire 1300B, the second stent body 1100B moves, and as the second stent body 1100B moves, the segment of the second stent body 1100B is the first stent body. It can be spaced apart from the mouse structure of (1100A).

Meanwhile, while the thrombus removal device 1000 is transformed from the first state to the second state, the thrombus removal device 1000 may receive an external force. Accordingly, the ratio of the length of the second stent body 1100B to the first stent body 1100A may vary. For example, when the second stent body 1100B is excessively deformed according to the second pull wire 1300B manipulation, the segment of the mouse structure of the first stent body 1100A and the second stent body 1100B corresponds or , may not be separated. Accordingly, the shape of the thrombus removal device 1000 may not change to the preset first state or the second state.

The anti-stretch mechanism may limit length deformation of the first stent body 1100A and the second stent body 1100 . Through this, the length ratio of the second stent body 1100B to the first stent body 1100A may be maintained within a certain range before and after the external force is applied. Through this, the thrombus removal device 1000 may be deformed to have a shape of a preset first state or a shape of a preset second state.

Here, the anti-stretching mechanism may be provided in the form of the first anti-stretching wire 1500A and the second anti-stretching wire 1500B or the anti-stretching strut 1700, and may be provided in other forms not mentioned.

The thrombus removal device may be in a second state (S2500). When the thrombus removal device 1000 is in the second state, a segment of the second stent body 1100B may correspond to a segment of the first stent body 1100A. The segment of the first stent body 1100A and the segment of the second stent body 1100B may overlap, and the segment of the first stent body 1100A located at the outer diameter of the second stent body 1100B is in contact with the vessel wall. can The mouth structure of the first stent body 1100A may not be covered by the segment of the second stent body 1100B. The mouse structure of the first stent body 1100A and the mouse structure of the second stent body 1100B may overlap, and an opening region of the mouse structure may be opened. The thrombus removal device 1000 engages the thrombus through the segments of the first stent body 1100A and the second stent body 1100B, and the mouse structure of the first stent body 1100A and the second stent body 1100B thrombus can be invited through. Through this, the thrombus removal device 1000 binds to the thrombus and captures the thrombus by accommodating the thrombi in the first stent body 1100A and the second stent body 1100B.

The step (S2600) of the thrombus removal device receiving an external force and the step (S2700) of the anti-stretching mechanism preventing the thrombus removal device from being deformed in length may be described with reference to S1400 and S1500 described above.

The methods according to the embodiments of the present specification described above may be used alone or in combination with each other. In addition, since each step described in each method is not essential, each method may include all of the steps and may be performed including only a part of the steps. In addition, since the order in which each step is described is only for convenience of description, each step in the above-described method does not necessarily have to be performed in the described order.

The above description is merely illustrative of the technical spirit of the present invention, and various modifications and variations will be possible without departing from the essential characteristics of the present invention by those skilled in the art to which the present invention pertains. Accordingly, the embodiments of the present specification described above may be implemented separately or in combination with each other.

Accordingly, the embodiments disclosed in the present specification are for explanation rather than limiting the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

Claims (7)

A thrombus removal device defined by a strut and comprising a plurality of cells having one proximal end, one distal end and two circumferential ends,
a strut structure including a first plurality of cells arranged in a first column and a second plurality of cells arranged in a second column adjacent to the first column; and
a pull wire operatively coupled to the strut structure;
includes,
One circumferential end provided in one cell of the first plurality of cells is connected to one circumferential end provided in the other cell of the first plurality of cells,
One circumferential end provided in one cell of the second plurality of cells is connected to one circumferential end provided in the other cell of the second plurality of cells,
The proximal end of each of the second plurality of cells is connected to the distal end of each of the first plurality of cells,
The plurality of cells includes a plurality of normal cells and a plurality of anti-stretching cells, wherein the anti-stretching cell further has an anti-stretching strut for limiting a change in length of the anti-stretching cell compared to the normal cell,
The first plurality of cells include at least one first anti-stretching cell and a plurality of first normal cells,
The second plurality of cells include at least one second anti-stretching cell and a plurality of second normal cells,
a distal end of the at least one first anti-stretching cell is connected to a proximal end of one of the plurality of second normal cells;
a proximal end of the at least one second anti-stretching cell is connected to a distal end of one of the plurality of first normal cells;
thrombus removal device. The method of claim 1,
Further comprising a plurality of third cells arranged in a third column adjacent to the first column,
Each of the third plurality of cells has one proximal end, one distal end and two circumferential ends,
One circumferential end provided in one cell of the third plurality of cells is connected to one circumferential end provided in the other cell of the third plurality of cells,
The distal end of each of the third plurality of cells is connected to the proximal end of each of the first plurality of cells,
The third plurality of cells includes at least one third anti-stretching cell and a plurality of third normal cells.
thrombus removal device. 3. The method of claim 2,
a distal end of the at least one third anti-stretching cell is connected to a proximal end of one of the plurality of first normal cells;
thrombus removal device. The method of claim 1,
The anti-stretching strut provided in the anti-stretching cell extends from the proximal end of the anti-stretching cell to the distal end of the anti-stretching cell.
thrombus removal device. The method of claim 1,
The anti-stretching strut provided in the anti-stretching cell extends from a first point on the strut defining the anti-stretching cell to a second point on the strut defining the anti-stretching cell,
The second point is different from the first point
thrombus removal device. 6. The method of claim 5,
the first point is closer to the proximal end of the anti-stretching cell than the second point,
The second point is closer to the distal end of the anti-stretching cell than the first point.
thrombus removal device. The method of claim 1,
The distal end of the cell is closer to the pull wire than the proximal end of the cell.
thrombus removal device.

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