Embolism protection device

Abstract

The invention belongs to the technical field of medical instruments, and particularly relates to an embolism protection device. The embolism protection device comprises an embolism protection net, and the embolism protection net sequentially comprises an initial section, a middle section and a final section in the direction from the far end to the near end; the main body of the embolism protection net is composed of a plurality of cells; the initial section is provided with a first cell; the middle section and / or the final section are / is provided with a second cell, the second cell is provided with an extension rod, one end of the extension rod is connected with the cell at the near end of the extension rod, and the other end of the extension rod is slidably assembled with the cell at the far end of the extension rod; and the extension rods are used for adjusting the mesh size of at least part of the cells. The embolism protection device is helpful to be placed at a farther-end position through the blocking section, and is also helpful to reduce the occurrence of missed capture of fine particles.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical devices, and particularly relates to an embolic protection device. BACKGROUND

[0002] Intracranial arterial occlusion is one of the main causes of ischemic stroke, accounting for about 25%-40% of all ischemic strokes (according to a study in the New England Journal of Medicine in 2020). Globally, there are about 12 million new cases of intracranial arterial occlusion-related stroke each year, of which about 30% are acute occlusions and 70% are chronic progressive occlusions. Among them, the intracranial segment of the internal carotid artery (C6-C7) and the middle cerebral artery (M1 segment) are the most common occlusion sites, accounting for 60%-70%.

[0003] Most of the filter screen embolic protection devices on the market are placed in the C1-C4 segment, and the delivery outer diameter of the embolic protection device is relatively large, which cannot pass through the intracranial occlusion segment to a higher position. And the thrombus of slow occlusion is mostly fibrosis or calcification, and the traditional filter screen is easy to miss small thrombus particles.

[0004] Therefore, it is necessary to further improve the existing filter screen embolic protection device. SUMMARY

[0005] The purpose of the present application is to provide an embolic protection device to help solve or improve at least one of the problems of the existing filter screen embolic protection device, such as difficulty in passing through the occlusion site to reach a more distal position, easy to block, and easy to miss small particles.

[0006] The embolic protection device of the present application adopts the following technical solution: an embolic protection device, comprising an embolic protection net, in the direction from the distal end to the proximal end, the embolic protection net comprises a starting segment, an intermediate segment and a terminal segment in sequence; the main body of the embolic protection net is composed of a plurality of unit cells; the starting segment has a first unit cell; the intermediate segment and / or the terminal segment has a second unit cell, the second unit cell has an extension rod, one end of the extension rod is connected with the unit cell at its proximal end, and the other end of the extension rod is slidably assembled with the unit cell at its distal end; the extension rod is used to adjust the mesh size of at least part of the unit cells.

[0007] Preferably, a sliding block is provided on the extension rod, the unit cell is connected by a first main rod and a second main rod, at least part of the first main rod is provided with a groove, and the groove is matched with the sliding block.

[0008] Preferably, a connecting wire is further provided between the sliding block and the extension rod, one end of the connecting wire is connected with the sliding block, and the other end of the connecting wire is connected with the extension rod.

[0009] Preferably, the first main rod is arranged at the proximal end of the second main rod; and the slider is pre-assembled at the distal end of the groove.

[0010] Preferably, the embolic protection device further comprises a delivery guide wire for delivering the embolic protection net; the delivery guide wire comprises an outer layer guide wire, an intermediate layer guide wire and an inner layer guide wire; the outer layer guide wire is connected with the terminal section; the intermediate layer guide wire is arranged through the outer layer guide wire and connected with the intermediate section; and the inner layer guide wire is arranged through the intermediate layer guide wire and connected with the initial section.

[0011] Preferably, the distal end of the inner layer guide wire is in J shape.

[0012] Preferably, the embolic protection device further comprises a recovery pulling wire, the distal end of the recovery pulling wire is connected with the embolic protection net, and the proximal end of the recovery pulling wire is connected with the delivery guide wire.

[0013] Preferably, the maximum mesh area of the embolic protection net of the initial section is less than 200 μm; the diameter of the embolic protection device is 2.5 mm-3.5 mm, and the outer diameter of the micro catheter for delivering the embolic protection device is less than 2.1 F.

[0014] Beneficial effects:

[0015] The embolic protection device of the present application is helpful to realize step-by-step delivery of the embolic protection net, reduce the delivery outer diameter of the embolic protection device, and make it easier to be placed at the distal end through the intracranial occlusion section, by segmenting the embolic protection net (including the initial section, the intermediate section and the terminal section).

[0016] In the embolic protection device of the present application, the second unit cell has an extension rod, and the extension rod is slidably assembled with the unit cell at the distal end of the extension rod, so as to help to divide the unit cell more finely through the layering design of the unit cell, and further help to realize the adjustment of the mesh size of at least part of the unit cell by adjusting the extension rod when necessary, and reduce the occurrence of fine particle leakage. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the embolic protection device of an embodiment of the present application;

[0018] Figure 2 It is a schematic diagram of the partial structure of the delivery guide wire of an embodiment of the present application;

[0019] Figure 3 It is a schematic diagram of the exploded structure of the embolic protection net of an embodiment of the present application;

[0020] Figure 4 It is a schematic diagram of the unfolded structure of the intermediate section or the distal section of the embolic protection net of an embodiment of the present application;

[0021] Figure 5 Structure diagram of a second unit cell of an embodiment of the present application; wherein (a) is a structure diagram of the whole second unit cell, (b) is an enlarged structure diagram of the groove in the A-A direction in (a); (c) is an enlarged structure diagram of the extension rod;

[0022] Figure 6 Structure diagram of the connection of two adjacent second unit cells in a pre-assembly state according to an embodiment of the present application; wherein (a) is a structure diagram of the whole; (b) is an enlarged structure diagram of the connection of the sliding block and the groove;

[0023] Figure 7 Structure diagram of the sliding of the extension rod relative to the unit cell at the distal end of the extension rod in two adjacent second unit cells in a retraction state according to an embodiment of the present application;

[0024] Figure 8 Another structure diagram of the connection of two adjacent second unit cells according to an embodiment of the present application;

[0025] Figure 9 Structure diagram of a connection state of an embolic protection net according to an embodiment of the present application;

[0026] Figure 10 Another structure diagram of a connection state of an embolic protection net according to an embodiment of the present application.

[0027] Reference signs:

[0028] 1 - delivery guide wire; 2 - embolic protection net; 3 - recovery pull wire;

[0029] 10 - inner layer guide wire; 11 - middle layer guide wire; 12 - outer layer guide wire;

[0030] 21 - starting section, 22 - middle section; 23 - terminal section; 210 - first unit cell; 220 - second unit cell; 221 - first main rod; 2211 - groove; 222 - second main rod; 223 - extension rod; 2231 - sliding block; 2232 - connecting wire; DETAILED DESCRIPTION

[0031] The preferred embodiments of the present application will be described in detail below with reference to the embodiments. It should be understood that the following embodiments are given only for the purpose of illustration and are not intended to limit the scope of protection of the present application. Those skilled in the art can make various modifications and replacements to the present application without departing from the spirit and principles of the present application, and all these modifications and replacements fall within the scope of protection of the present application claimed in the claims.

[0032] In the description of the present application, it needs to be understood that the orientation description, such as the orientation or position relationship indicated by the upper, lower, front, rear, left, right and the like, is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0033] In the description of the present application, the meaning of one or more is one or more, the meaning of multiple is two or more, greater than, less than, more than and the like are understood as not including the number, above, below, within and the like are understood as including the number. If the first, second is described, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the sequence of technical features indicated.

[0034] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited by "first" and "second" can explicitly or implicitly include one or more features.

[0035] In the description of the present application, it needs to be pointed out that, unless otherwise explicitly specified and limited, the term "connection" should be understood broadly, for example, it can be fixed connection or movable connection, or detachable connection or non-detachable connection, or integral connection; it can be mechanical connection, or electrical connection or can communicate with each other; it can be directly connected, or indirectly connected through intermediate medium, or the internal communication of two elements, indirect communication or the interaction relationship of two elements.

[0036] The present application will be described in detail below with reference to the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0037] In the following description, the end close to the operator is the proximal end, and the end away from the operator is the distal end.

[0038] In view of at least one of the problems that the current filter screen type embolic protection device is difficult to reach a more distal position through the occlusion site, is prone to blockage and small particles are prone to escape, the present application provides an embolic protection device.

[0039] As Figures 1-3As shown, the embolic protection device of the embodiment of the present application comprises an embolic protection net 2, which comprises a starting section 21, a middle section 22 and a terminal section 23 (the outer diameters of the starting section 21, the middle section 22 and the terminal section 23 gradually increase) in the direction from the distal end to the proximal end; the main body of the embolic protection net is composed of a plurality of unit cells; the starting section 21 has first unit cells 210; the middle section 22 and / or the terminal section 23 have second unit cells 220, the second unit cells 220 have extension rods 223, one end of the extension rod 223 is connected with the unit cell at the proximal end thereof, and the other end of the extension rod 223 is slidingly assembled with the unit cell at the distal end thereof; the extension rod 223 is used for adjusting the mesh size of at least part of the unit cells (the extension rod 223 can also play a role of connecting and assembling the unit cells to form the embolic protection net in the present application). Among them, the first unit cells 210 and the second unit cells 220 are only used to distinguish whether the unit cell at the distal end is connected with the extension rod 223, the unit cell at the distal end without the extension rod 223 is the first unit cell 210, and the unit cell at the distal end connected with the extension rod 223 is the second unit cell 220; the description of the first unit cells 210 and the second unit cells 220 does not constitute a limitation on the shape and size of the unit cells, and the unit cells of the starting section 21, the middle section 22 and the terminal section 23 can be independently selected according to actual needs.

[0040] By segmenting the embolic protection net (the starting section 21, the middle section 22 and the terminal section 23), the embolic protection device of the present application can be conveniently transported step by step, the outer diameter of the embolic protection device is reduced, and it is easier to pass through the occlusion section and be placed at a more distal position. Specifically, if the embolic protection net is not segmented, the radial size of the embolic protection net per unit area will increase due to the overlapping of the structure in the crimped state, which is not conducive to the transportation of the embolic protection net (the transportation of the embolic protection net is carried out in the crimped state), and it is difficult to pass through the occlusion section and be placed at a more distal position. The embolic protection net of the present application can be transported step by step, and the mutual overlapping between the starting section 21, the middle section 22 and the terminal section 23 in the crimped state can be significantly improved, which is conducive to reducing the outer diameter of the embolic protection net of the present application during transportation, and making it easier to pass through the occlusion section and be placed at a more distal position.

[0041] In addition, the extension rod 223 can be adjusted according to the relative position between the extension rod 223 and the unit cell at the distal end thereof, which is conducive to adjusting the mesh size of at least part of the unit cells, reducing or avoiding the leakage of small particles, and ensuring the effect of embolic capture; and it is also conducive to avoiding new vascular embolism caused by the leakage of small particles and reducing the risk of surgery.

[0042] In the preferred embodiment of the embolic protection device of the present application, as shown in the drawings, Figure 4As shown in the drawings, the extension rod 223 is provided with a sliding block 2231, and the cell is connected by the first main rod 221 and the second main rod 222, and at least part of the first main rod 221 is provided with a groove 2211 which is matched with the sliding block 2231. Wherein, the first main rod 221 and the second main rod 222 are only used to distinguish whether they contain the groove matched with the sliding block 2231; "at least part of the first main rod 221 is provided with the groove 2211" means that the present application does not require that the first main rod 221 is provided with the groove 2211 at any position, and the groove matched with the sliding block 2231 can be arranged at the local part of the first main rod 221 according to the need.

[0043] Preferably, as Figure 5 As shown in the drawings, the sliding block 2231 is in the shape of a spherical ball; the size of the opening end of the groove 2211 is smaller than the diameter of the sliding block 2231. The above arrangement makes the sliding block 2231 stably located in the groove 2211, avoiding the sliding block 2231 from being taken out of the groove 2211.

[0044] Preferably, the sliding block 2231 and the extension rod 223 are further provided with a connecting wire 2232, one end of the connecting wire 2232 is connected with the sliding block 2231, and the other end is connected with the extension rod 223.

[0045] Preferably, the sliding block 2231 is arranged at the position close to the distal end of the extension rod 223.

[0046] In the preferred embodiment of the embolic protection device of the present application, as Figures 6-7 As shown in the drawings, the first main rod 221 is arranged at the proximal end of the second main rod 222, and the sliding block 2231 is pre-assembled at the distal end of the groove 2211. Wherein, "pre-assembled" means that the sliding block 2231 is arranged at the distal end of the groove 2211 before the embolic protection device of the present application is used; such arrangement makes the sliding block 2231 receive the pushing force for moving to the distal end during the process of pushing the embolic protection device of the present application to the distal end, and the cell at the distal end of the sliding block 2231 is limited by the distal end of the groove 2211 and can only act on the cell at the distal end, promoting the cell at the distal end to move to the distal end; in addition, due to the arrangement of the extension rod 223, the distance between the cell at the proximal end of the extension rod 223 and the cell at the distal end of the extension rod 223 is maintained constant (which helps to avoid the increase of the radial size caused by the stacking of the embolic protection nets at different positions in the compressed state), which helps to reduce the pushing force required for moving to the distal end in the delivery catheter.

[0047] Preferably, a notch is arranged on the groove 2211 near the proximal end of the first body rod 221 to allow the slider 2231 to move distally (to allow the slider 2231 to move out of the groove 2211 when it reaches the notch of the groove 2211 and continue to move distally), and a guide limiting groove is arranged near the proximal end of the second body rod 221 to guide and limit the movement of the slider (to prevent or limit the movement of the slider 2231 distally after it passes through the limiting guide groove).

[0048] Preferably, the structure of the guide limiting groove can be as shown by the shadow at the distal end of the unit cell in Figure 4 (the guide limiting groove has a distally inclined concave surface).

[0049] Preferably, as shown in Figure 4 , grooves 2211 can also be arranged on the second body rod 222 as needed (for example, they can be arranged on the second body rod 222 adjacent to the first body rod on which the groove 2211 in Figure 4 is arranged, or they can be arranged on the second body rod 222 corresponding to (i.e., not adjacent to) the groove 2211 in Figure 4 ; when the groove 2211 is arranged on the second body rod 222 not adjacent to the groove 2211 in , the notch of the groove 2211 can be arranged outside the unit cell on which the groove 2211 is arranged).

[0050] Figures 1-3 In the preferred embodiment of the embolic protection device of the present application, as shown in , the embolic protection device further comprises a delivery guide wire 1 for delivering the embolic protection net; the delivery guide wire 1 comprises an outer guide wire 12, an intermediate layer guide wire 11, and an inner guide wire 10, the outer guide wire 12 is connected to the terminal segment 23; the intermediate layer guide wire 11 is arranged through the outer guide wire 12 (the outer guide wire 12 is in the form of a hollow tube, and the axial length of the intermediate layer guide wire 11 is greater than that of the outer guide wire 12), and is connected to the intermediate segment 22; the inner guide wire 10 is arranged through the intermediate layer guide wire 11 (the intermediate layer guide wire 11 is in the form of a hollow tube, and the axial length of the inner guide wire 10 is greater than that of the intermediate layer guide wire 11), and is connected to the starting segment 21. The arrangement of the outer guide wire 12, the intermediate layer guide wire 11, and the inner guide wire 10 makes it possible to push, retract, or rotate the starting segment 21, the intermediate segment 11, and the terminal segment 23 as needed, and the operation is more flexible and convenient.

[0051] Preferably, the inner diameter of the intermediate layer guide wire 11 is greater than the outer diameter of the inner guide wire 10, and the inner diameter of the outer guide wire 12 is greater than the outer diameter of the intermediate layer guide wire 11. The above arrangement helps the outer guide wire 12, the intermediate layer guide wire 11, and the inner guide wire 10 to independently complete the forward pushing, backward retraction, and rotation actions without interfering with each other.

[0052]

[0052] In the preferred embodiment of the embolic protection device of the present application, the distal end of the inner layer guide wire 10 is J-shaped (or pigtail-shaped). The shape of the distal end of the inner layer guide wire 10 helps to reduce or avoid damage to the distal tissue and improve the safety of the embolic protection device of the present application.

[0053] In the preferred embodiment of the embolic protection device of the present application, the embolic protection device further comprises a recovery pull wire 3, the distal end of the recovery pull wire 3 is connected to the embolic protection net, and the proximal end of the recovery pull wire 3 is connected to the delivery guide wire.

[0054] In the preferred embodiment of the embolic protection device of the present application, the maximum mesh area of the embolic protection net of the initial segment is less than 200 μm; the diameter of the embolic protection device is 2.5 mm-3.5 mm (for example, 2.5 mm, 2.8 mm, 3.0 mm, 3.2 mm or 3.5 mm), and the outer diameter of the microcatheter for delivering the embolic protection device of the present application is <2.1F.

[0055] In the preferred embodiment of the embolic protection device of the present application, the embolic protection device comprises a delivery guide wire 1, an embolic protection net 2 and a recovery pull wire 3, as shown in Figure 1 2 The distal end of the delivery guide wire 1 can be pre-shaped as J-shaped or pigtail-shaped (preferably, the length of the distal end can be 1 cm). The delivery guide wire is composed of an inner layer guide wire 10, an intermediate layer guide wire 11 and an outer layer guide wire 12, the inner layer guide wire 10 is located in the innermost layer and has the longest length; the intermediate layer guide wire 11 is a hollow tube in the middle layer, which can complete the forward pushing, backward withdrawing and rotating actions by the force applied through the proximal end; the outermost layer is the outer layer guide wire 12, and the inner layer guide wire 10, the intermediate layer guide wire 11 and the outer layer guide wire 12 can all independently complete the forward pushing, backward withdrawing and rotating actions without interfering with each other. The initial segment 21 is covered with a film, the maximum mesh area is less than 200 μm, and the outer diameter of the microcatheter for delivering the embolic protection device of the present application is 2.1F or less. The diameter of the embolic protection device of the present application is 2.5 mm-3 mm; the design of the head-end guide wire is similar to the structure of the Transend guide wire (Stryker) and the spring design. The embolic protection net 2 is composed of multiple segments according to different lengths, as shown in Figure 3 The initial segment 21 of the embolic protection net 2 can be cut and shaped as a cone by a nickel-titanium small tube segment, one end of which is connected to the inner layer guide wire 10 and can slide on the inner layer guide wire 10. The intermediate segment 22 and the terminal segment 23 have different angles, and the second unit cell 220 has a fixed structure, as shown in Figure 4 The unit cells are regularly arranged in the circumferential direction in the axial direction; one end of the intermediate segment 22 is connected to the initial segment 21, and the other end is connected to the intermediate layer guide wire 11; one end of the terminal segment 23 is connected to the intermediate segment 22, and the other end is connected to the outer layer guide wire 12.

[0056] ​The embolism protection net 2 is mainly composed of unit cells, and the unit cells include first unit cell 210 and second unit cell 220; the first unit cell 210 includes first main rod 221 and second main rod 222 (preferably, the first main rod 221 is arranged at the proximal end of the second main rod 222), and the first main rod 221 and the second main rod 222 are connected to form a main body of the unit cell; the second unit cell 220 further includes an extension rod 223 connected to the distal end of the main body of the unit cell (the second unit cell 220 includes the first main rod 221, the second main rod 222 and the extension rod 223).

[0057] As shown in Figure 5 , the first main rod 221 and the second main rod 222 form a main body of the unit cell, the distal end of the second unit cell 220 is provided with the extension rod 223, the extension rod 223 is provided with a connecting wire 2232 (a metal wire can be used), one end of the connecting wire 2232 is connected with the extension rod 223, and the other end is connected with a sliding block 2231 (preferably, the sliding block 2231 can be in the form of a ball; more preferably, the sliding block 2232 can be a stainless steel ball).

[0058] As shown in Figure 6 , in the pre-assembly state, the front and rear unit cells are staggered with each other, the sliding block 2231 on the extension rod 223 of the proximal second unit cell is arranged in the groove 2211 on the first main rod 221 of the distal second unit cell, and can slide in the groove 2211. During the pushing process, the proximal second unit cell and the distal unit cell always maintain a front and rear distance, thereby reducing the pushing force in the delivery catheter.

[0059] By rotating and pushing and retracting the intermediate layer guide wire 11, the sliding block 2231 of the intermediate segment 22 can be relatively slid along the groove 2211 of the starting segment 21, the sliding block 2231 moves along the path shown in Figure 7 with the intermediate segment 22, and finally completes the mutual state shown in Figure 8 . The synchronous relative rotation movement operation is completed on the terminal segment 23 (refer to the path shown in Figure 7 ), and the relative gap between the grids changes from Figure 9 to Figure 10 . The intervention of the extension rod makes the grid further refined.

[0060] Although the present application has been described in detail by the general description and specific embodiments above, some modifications or improvements can be made on the basis of the present application, which is obvious to those skilled in the art. Therefore, these modifications or improvements made on the basis of not deviating from the spirit of the present application, all belong to the scope of protection claimed by the present application.

Claims

1. An embolic protection device, comprising: The embolic protection device comprises an embolic protection net, which comprises a starting section, an intermediate section and a terminal section in the direction from the distal end to the proximal end; the main body of the embolic protection net is composed of a plurality of unit cells; The starting section has first unit cells; The intermediate section and / or the terminal section have second unit cells, which have extension rods, one end of the extension rod is connected with the unit cell at the proximal end thereof, and the other end of the extension rod is slidably assembled with the unit cell at the distal end thereof; The extension rod is used for adjusting the mesh size of at least part of the unit cells.

2. The embolism protection device as described in claim 1, characterized in that, A sliding block is arranged on the extension rod, the unit cells are connected by first main rods and second main rods, at least part of the first main rods are provided with grooves, and the grooves are matched with the sliding blocks.

3. The embolic protection device of claim 2, wherein the distal end of the elongate member is configured to be positioned in the aortic arch. A connecting wire is further arranged between the sliding block and the extension rod, one end of the connecting wire is connected with the sliding block, and the other end of the connecting wire is connected with the extension rod.

4. The embolic protection device of claim 2, wherein the distal end of the elongate member is configured to be positioned in the aortic arch. The first main rods are arranged at the proximal end of the second main rods; The sliding block is pre-assembled at the distal end of the groove.

5. The embolism protection device as described in claim 1, characterized in that, The embolic protection device further comprises a delivery guide wire, which is used for delivering the embolic protection net; The delivery guide wire comprises an outer guide wire, an intermediate layer guide wire and an inner layer guide wire, the outer guide wire is connected with the terminal section; The intermediate layer guide wire is arranged through the outer guide wire and is connected with the intermediate section; The inner layer guide wire is arranged through the intermediate layer guide wire and is connected with the starting section.

6. The embolic protection device of claim 5, wherein the distal end of the elongate member is configured to be positioned in the aortic arch. The distal end of the inner layer guide wire is in J shape.

7. The embolic protection device of claim 5, wherein the distal end of the elongate member is configured to be positioned in the aortic arch. The embolic protection device further comprises a recovery pulling wire, the distal end of the recovery pulling wire is connected with the embolic protection net, and the proximal end of the recovery pulling wire is connected with the delivery guide wire.

8. The embolic protection device of any of claims 1-7, wherein, The maximum mesh area of the embolic protection net of the starting section is less than 200 μm; The diameter of the embolic protection device is 2.5 mm-3.5 mm, and the outer diameter of the microcatheter for delivering the embolic protection device is <2.1F.

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