Thrombectomy device

Abstract

The thrombectomy device comprises a thrombectomy support, a traction wire and a traction rod, an inner cavity is formed in the thrombectomy support, the thrombectomy support comprises a cutting part located at the near end, an opening communicated with the inner cavity is formed in the cutting part, and the cutting part comprises a far-end end and a near-end end; the thrombectomy stent can be radially compressed and self-expandable, the thrombectomy stent can be radially compressed to a loading size under the action of binding force, and after the binding force is removed, the thrombectomy stent can be self-expanded to a radial expansion state; the traction rod is connected with the end part of the near end; the pull wire is a flexible piece, the far end of the pull wire is connected with the thrombectomy support, and the connecting point of the pull wire and the thrombectomy support is located at the far end of the far end portion or the axial distance between the connecting point and the far end portion is zero. According to the thrombectomy device, the radial supporting force of the open end does not need to be improved, but the thrombectomy efficiency is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, and in particular to a thrombectomy device. BACKGROUND

[0002] This section provides background information only and can not necessarily be prior art.

[0003] Deep vein thrombosis is a venous disease caused by abnormal coagulation of blood in the deep veins of the lower limbs, referred to as DVT, which can cause occlusion of the venous vessels, leading to pain, swelling and other symptoms in the lower limbs due to the inability of blood to return to the heart normally, and when the embolus is detached and flows into the lungs with the blood circulation, it can cause pulmonary embolism (PE), which can be fatal to the patient.

[0004] The current treatment for DVT mainly includes mechanical thrombectomy. Mechanical thrombectomy mainly involves extending a thrombectomy stent into the blood vessel and placing it distal to the thrombus, then expanding the thrombectomy stent in the blood vessel and attaching it to the blood vessel wall, and then dragging the thrombectomy stent proximally relative to the blood vessel to move axially proximally. During the axial proximal movement of the thrombectomy stent relative to the blood vessel, the thrombectomy stent can intercept the thrombus in the blood vessel and scrape off the thrombus on the blood vessel wall and collect it in the thrombectomy stent. Finally, the thrombectomy stent with the collected thrombus is withdrawn to the outside of the body, thereby removing the thrombus outside the body and restoring blood flow. The treatment method of mechanical thrombectomy can avoid or reduce the use of anticoagulants and has less blood loss.

[0005] An ideal thrombectomy device should at least have the following characteristics: sufficient single thrombectomy capacity and less damage to the blood vessel. However, the thrombectomy stent is usually made of metal material, for example, made of nickel-titanium alloy material, and the thrombectomy stent should have a certain radial support performance to avoid collapsing during thrombectomy and reduce the thrombus loading capacity. In order to avoid the opening end from shrinking and reducing the amount of thrombus scraped off to improve the thrombectomy efficiency, the commonly used method is to increase the radial support force of the opening end. In this way, the blood vessel wall is easily damaged during the process of scraping off the thrombus, causing secondary injury to the patient. SUMMARY

[0006] Therefore, it is necessary to provide a thrombectomy device that does not need to increase the radial support force of the opening end but has high thrombectomy efficiency.

[0007] The device for removing thrombus comprises a thrombus-removing stent, a traction wire and a traction rod, the thrombus-removing stent is formed with an inner cavity, the thrombus-removing stent comprises a cutting part at a proximal end, the cutting part is formed with an opening communicating with the inner cavity, the cutting part comprises a distal end and a proximal end; the thrombus-removing stent is radially compressible and self-expandable, the thrombus-removing stent can be radially compressed to a loading size under a binding force, after the binding force is removed, the thrombus-removing stent can be self-expanded to a radially expanded state; the traction rod is connected with the proximal end; the traction wire is a flexible member, a distal end of the traction wire is connected with the thrombus-removing stent, and a connection point of the traction wire and the thrombus-removing stent is located at a distal end of the distal end or an axial distance between the connection point and the distal end is zero.

[0008] The device for removing thrombus comprises a thrombus-removing stent, a traction wire and a traction rod, the thrombus-removing stent is formed with an inner cavity, the thrombus-removing stent comprises a cutting part at a proximal end, the cutting part is formed with an opening communicating with the inner cavity, the cutting part comprises a distal end and a proximal end; the thrombus-removing stent is radially compressible and self-expandable, the thrombus-removing stent can be radially compressed to a loading size under a binding force, after the binding force is removed, the thrombus-removing stent can be self-expanded to a radially expanded state; the traction rod is connected with the proximal end; the traction wire is a flexible member, a distal end of the traction wire is connected with the thrombus-removing stent, and a connection point of the traction wire and the thrombus-removing stent is located at a distal end of the distal end or an axial distance between the connection point and the distal end is zero.

[0009] Thus, the device for removing thrombus does not need to improve the radial support force of the opening end but has a high thrombus-removing efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort based on these drawings.

[0011] wherein:

[0012] Figure 1 is a perspective view of a stentriever device in an embodiment, wherein the handle of the stentriever device is not shown in the figure;

[0013] Figure 2 is a schematic structural view of a stentriever device in an embodiment, wherein the handle of the stentriever device is not shown in the figure;

[0014] Figure 3 is a schematic structural view of a pull wire and a stentriever support in an embodiment, wherein Figure 3 the mesh structure of the stentriever support is hidden for the convenience of showing the pull wire, and Figure 3 the pull wire is in a tensioned state in the figure;

[0015] Figure 4 is a schematic structural view of a stentriever support in an embodiment shown in Figure 2 ;

[0016] Figure 5 is a view of the third interval segment unfolded in Figure 4 ;

[0017] Figure 6 is a schematic structural view of a pull rod in an embodiment;

[0018] Figure 7 is a view of a stentriever device in an embodiment shown in Figure 6 , during a stentriever process, wherein Figure 7 the delivery sheath and the handle are hidden in the figure;

[0019] Figure 8 is a schematic structural view of a pull rod in another embodiment;

[0020] Figure 9 is a view of a cutting portion and a distal segment of a pull rod in an embodiment shown in Figure 8 ;

[0021] Figure 10 is a perspective view of a delivery sheath and a handle in a stentriever device in an embodiment. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0023] In the description of the embodiments of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0024] In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be replaceably connected, or it can be integrally connected, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0025] In the field of interventional medical devices, the end of a medical device implanted in the human or animal body closer to the operator is generally referred to as the "proximal end", and the end farther from the operator is referred to as the "distal end", and the "proximal end" and "distal end" of any component of the medical device are defined according to this principle. "Axial" generally refers to the length direction of the medical device when it is being delivered, "radial" generally refers to the direction of the medical device that is not parallel to its "axial" direction, and the "axial" and "radial" of any component of the medical device are defined according to this principle. "Circumferential" refers to the circumferential direction, i.e. the axial direction around the lumen structure, the cylinder.

[0026] Please refer to Figure 1 The present disclosure provides a thrombectomy device 2, comprising a thrombectomy stent 21, a pulling rod 22 and a traction line 41, the pulling rod 22 is connected with the proximal end of the thrombectomy stent 21, and the traction line 41 is connected with the thrombectomy stent 21.

[0027] The thrombectomy stent 21 is a grid structure. The thrombectomy stent 21 can be woven with woven wire and then shaped, or can be cut from a hollow pipe and then shaped. The woven wire can be a nickel-titanium alloy wire, a stainless steel wire or other metal wire. The hollow pipe can be a nickel-titanium alloy pipe, a stainless steel pipe or other metal pipe, or a polymer pipe.

[0028] The thrombus-removing stent 21 is radially compressible, and is compressible to a loading size under a binding force (a radial compression force on the thrombus-removing stent 21 or an axial tension force applied to both ends of the thrombus-removing stent 21) so as to be loaded in a delivery sheath 23 (to be described below) for delivery in a blood vessel of a patient through the delivery sheath 23. The thrombus-removing stent 21 is self-expandable, and is expandable to a radially expanded state when the binding force on the thrombus-removing stent 21 is removed. For example, after the delivery sheath 23 sheathed on the thrombus-removing stent 21 is removed to be separated from the thrombus-removing stent 21, the thrombus-removing stent 21 is self-expandable to the radially expanded state.

[0029] Referring to Figure 1 and Figure 2 , the thrombus-removing stent 21 has a lumen, and includes a cutting portion 211 at a proximal end, which is a circumferentially closed ring structure. The cutting portion 211 is formed with an opening communicating with the lumen. In an embodiment, the cutting portion 211 includes a distal end portion 2111 and a proximal end portion 2112, and has an axial spacing between the distal end portion 2111 and the proximal end portion 2112. When the thrombus-removing stent 21 is located in a blood vessel and the binding force on the thrombus-removing stent 21 is removed, the thrombus-removing stent 21 is self-expandable to a radially expanded state, so that the cutting portion 211 is in abutment with a blood vessel wall of the blood vessel.

[0030] Referring to Figure 1 and Figure 2 , the pulling wire 41 is a flexible member, and a distal end of the pulling wire 41 is connected to the thrombus-removing stent 21. A connection point 411 of the pulling wire 41 to the thrombus-removing stent 21 is located distally of the distal end portion 2111 of the cutting portion 211. In other embodiments, the axial spacing between the connection point 411 and the distal end portion 2111 is zero. That is, the connection point 411 is diametrically opposite to the distal end portion 2111.

[0031] In the process of operating the thrombus-removing device 2 to remove thrombus, the cutting portion 211 of the thrombus-removing stent 21 is first located at a distal end of the thrombus, and the binding force on the thrombus-removing stent 21 is removed, so that the thrombus-removing stent 21 is self-expandable to make the cutting portion 211 in abutment with a blood vessel wall of the blood vessel. Since the cutting portion 211 is a circumferentially closed ring structure, the cutting portion 211 is able to abut the blood vessel wall in a circumferential direction of 360°. A pulling force is simultaneously applied to the pulling wire 41 and the pulling rod 22 to drive the thrombus-removing stent 21 to move proximally, so as to cut the thrombus on the blood vessel wall. The thrombus cut off by the cutting portion 211 enters the lumen of the thrombus-removing stent 21 through the opening and is captured, so as to be taken out of the body by the thrombus-removing stent 21.

[0032] In the process of cutting the thrombus by the cutting part 211, the thrombus is cut by the thrombus removing stent 21 driven by the traction line 41 and the traction rod 22. In the process of cutting the thrombus, the proximal end 2112 is subjected to the proximal end pointing driving force F1 of the traction rod 22, and also subjected to the distal end pointing resistance F2 of the thrombus, and F1 is greater than F2. At the same time, the traction rod 22 also generates a certain proximal end pointing driving force F3 on the distal end 2111, but F3 is less than F1, and the distal end 2111 is subjected to the distal end pointing resistance F4 of the thrombus, and F3 is less than F4, so that the resultant force acting on the distal end 2111 is from the proximal end to the distal end, and the resultant force acting on the proximal end 2112 is from the distal end to the proximal end. In this way, the cutting part 211 is subjected to axial forces in opposite directions, and under the action of no other counterforce, the cutting part 211 is subjected to axial stretching and radial contraction, so that it cannot maintain the wall-adhesion state. The connection point 411 of the traction line 41 and the thrombus removing stent 21 is located at the distal end of the distal end 2111 or the axial distance between the connection point 411 and the proximal end 2112 is zero. In the process of pulling the traction line 41, the driving force is transmitted to the distal end 2111, so that the distal end 2111 is subjected to the proximal end pointing driving force F5, thereby resisting the resistance of the distal end 2111, so that the distal end 2111 is subjected to the distal end pointing resultant force, or the distal end 2111 is subjected to the proximal end pointing force, so as to reduce the axial forces in opposite directions acting on the cutting part 211; or make the resultant force acting on the cutting part 211 only point to the proximal end; thereby slowing down or avoiding the radial contraction of the cutting part 211 in the cutting process, so as to improve the wall-adhesion, thereby improving the thrombus removing efficiency.

[0033] Moreover, the traction line 41 is a flexible member. If the distal end of the traction line 41 extends in the thrombus removing stent 21, compared with a rigid connecting rod, the wire diameter of the traction line 41 can be smaller, so as to less occupy the inner cavity of the thrombus removing stent 21, thereby less occupying the space for accommodating the thrombus; if the distal end of the traction line 41 is located outside the thrombus removing stent 21, compared with a rigid connecting rod, the wire diameter of the traction line 41 can be smaller, and will not occupy a certain space when extending axially from the distal end to the proximal end, so that the corresponding part of the thrombus removing stent 21 is not wall-adhesion, thereby improving the thrombus removing efficiency, and also helping to avoid thrombus escape.

[0034] Therefore, the thrombus removing device 2 does not need to increase the radial force of the opening end, but can slow down or avoid the deformation of the cutting part 211, and the thrombus removing efficiency is higher.

[0035] Generally, the inner diameter of a patient's blood vessel gradually decreases from a direction close to the heart to a direction away from the heart. In the present embodiment, during the process of driving the thrombus-removing stent 21 to move proximally (i.e. in a direction gradually away from the heart) in the patient's blood vessel for thrombus removal, since the inner diameter of the blood vessel (e.g. a deep vein blood vessel) gradually decreases in the moving direction of the thrombus-removing stent 21, if the radial supporting force exerted by the cutting portion 211 on the inner wall of the blood vessel is too large, the blood vessel wall of the patient will be damaged when the thrombus-removing stent 21 is moved to a blood vessel segment with a smaller inner diameter. The thrombus-removing device 2 described above can improve the wall-adhesion of the cutting portion 211 while maintaining the flexibility required by the cutting portion 211, and thus when the thrombus-removing stent 21 enters a blood vessel segment with a smaller inner diameter, the cutting portion 211 can automatically contract radially to deform to adapt to the smaller inner diameter of the blood vessel, thereby avoiding damage to the blood vessel wall of the patient during the thrombus removal process.

[0036] In an embodiment, the distal end of the traction wire 41 is connected to the thrombus-removing stent 21, and the traction wire 41 is wound around the mesh of the thrombus-removing stent 21 and extends proximally from the inner cavity of the thrombus-removing stent 21. The traction wire 41 is wound around the mesh of the thrombus-removing stent 21, so that the traction wire 41 can provide radial supporting force for the thrombus-removing stent 21, which helps to improve the structural stability of the thrombus-removing stent 21. The traction wire 41 is a flexible member and will not damage the blood vessel wall.

[0037] In the present embodiment, the traction wire 41 can be a flexible rope or a stainless steel wire with a certain flexibility.

[0038] Please refer to Figure 2 and Figure 3When the traction line 41 is in tension (for example, when the traction line 41 drives the stentriever 21 to move proximally), the segment of the traction line 41 close to the distal end forms an acute angle X with the straight line L extending along the axial direction of the stentriever 21 and passing through the distal end of the stentriever 21 and the proximal end 2112 of the cutting part 211, the acute angle X ranges from [0°, 18°], so that the circumferential length value of the connection point 411 to the straight line L is set in a small range, thereby limiting the component F6 of the traction line 41 at the connection point 411 to the stentriever 21 in the direction of the straight line L to a small range when the traction line 41 is driven to move proximally, thereby reducing the risk of the stentriever 21 collapsing at the connection point 411, and further reducing the risk of the mesh structure at the connection point 411 driving the cutting part 211 to collapse inward, thereby improving the adhesion of the cutting part 211 to the blood vessel during the stentriever process. In addition, while limiting the component F6 in the direction of the straight line L to a small range, the component F7 in the proximal direction (i.e., the force that can drive the stentriever 21 to move proximally) can be maintained in a large range, which can save force during the stentriever process. For the acute angle X, the smaller the value of the acute angle X, the smaller the value of F6, and the smaller the risk of the stentriever 21 collapsing at the connection point 411. In an embodiment, the acute angle X is equal to 0°, and the value of F6 is zero, thereby further reducing the risk of the stentriever 21 collapsing at the connection point 411 and reducing the risk of the mesh structure at the connection point 411 driving the cutting part 211 to collapse inward.

[0039] Please refer to Figure 1 The part of the traction line 411 in the length interval of the stentriever 21 extends in the lumen of the stentriever 21, and since the wire diameter of the traction line 41 can be small, it can occupy less space in the lumen of the stentriever 21, thereby less occupying the space for accommodating the thrombus. During the process of driving the stentriever 21 to stentriever by the traction line 41 under tension, the part of the traction line 411 in the length interval of the stentriever 21 extending in the lumen of the stentriever 21 can reduce the contact between the traction line 41 and the blood vessel wall, thereby avoiding damage to the blood vessel wall caused by the traction line 41.

[0040] Please refer to Figure 4 The stentriever 21 includes, from distal to proximal, a first interval segment 211, a second interval segment 212, and a third interval segment 213.

[0041] Please refer to Figure 4, the first interval segment 211 is tapered, the first interval segment 211 is a mesh structure, the smaller-diameter end of the first interval segment 211 is located at the distal end, the larger-diameter end is located at the proximal end, and the larger-diameter proximal end of the first interval segment 211 is connected to the second interval segment 212. The first interval segment 211 has a tapered inner cavity, and the larger-diameter end of the first interval segment 211 is an open end, and the smaller-diameter end is a closed end. The closed end is the closed end of the stent 21.

[0042] Please refer to Figure 3 and Figure 4 , the second interval segment 212 is a mesh structure, the second interval segment 212 is cylindrical, and has a cylindrical inner cavity with two open ends. The distal end of the second interval segment 212 is connected to the proximal end of the first interval segment 211. The end of the second interval segment 212 away from the first interval segment 211 is connected to the third interval segment 213. The connection point 411 is located in the second interval segment 212. In this embodiment, since the second interval segment 212 is cylindrical, its side wall extends in the axial direction, thereby making the axial support of the side wall of the second interval segment 212 stronger. When the driving force of the traction wire 41 is applied to the stent 21, the connection point 411 is arranged in the second interval segment 212, which can reduce the risk of axial deformation of the stent 21 under the driving force, thereby reducing the risk of the stent 21 collapsing in the radial direction at the connection point 411 due to the axial deformation of the stent 21, and reducing the risk of the mesh structure of the connection point 411 driving the cutting portion 211 to collapse inward and separate from the blood vessel wall.

[0043] Please refer to Figure 4 and Figure 5 , the third interval segment 213 is a mesh structure, the cutting portion 211 is located in the third interval segment 213, and the proximal end of the third interval segment 213 is connected to the second interval segment 212. When the third interval segment 213 is unfolded to be planar, the third interval segment 213 is an isosceles triangle. The third interval segment 213 includes a sharp corner portion 2131 at the proximal end and a wave-shaped portion (not labeled in the figure) at the distal end. Among them, the sharp corner portion 2131 is the proximal end portion 2112 of the cutting portion 211, and the distal end portion of the waist of the isosceles triangle is the distal end portion 2111 of the cutting portion 211 (see Figure 2 ).

[0044] The proximal end portion 2112 of the cutting portion 211 is a sharp corner portion 2131 wound as shown by Figure 5 , that is, the proximal end portion 2112 is a sharp end structure pointing to the proximal end. During the stentriever process, the cutting portion 211 with a sharp corner structure has less resistance and can better resist resistance and slow down the degree of deformation, thereby facilitating the cutting portion 211 to maintain the wall-adhering state.

[0045] And, the proximal end 2112 is a pointed end structure, so that the opening of the cutting portion 211 is elliptical or approximately elliptical, and the cutting portion 211 can play a guiding role when the thrombus-removing stent 21 passes through the venous valve, thereby facilitating the thrombus-removing stent 21 to pass through the venous valve and avoiding the cutting portion 211 from scratching the venous valve.

[0046] Please refer to Figure 4 , the thrombus-removing stent 21 further comprises a collar 214 connected to the proximal end 2112 of the cutting portion 211 through a connecting rod 215.

[0047] Please refer to Figure 2 , the pulling rod 22 is a hollow tubular structure. The distal end of the pulling rod 22 is connected to the collar 214, so that the pulling rod 22 is connected to the proximal end 2112 of the cutting portion 211 through the collar 214 and the connecting rod 215, and the pulling rod 22 can exert a force on the thrombus-removing stent 21, so that the thrombus-removing stent 21 is pushed to the distal end of the thrombus during the thrombectomy.

[0048] Please refer to Figure 2 and Figure 6 , in this embodiment, the pulling rod 22 comprises a distal segment 221 and a proximal segment 222 connected in sequence from distal to proximal. The distal segment 221 is connected to the collar 214, and the distal segment 221 is flexible so that it can be bent and deformed when subjected to a radial force. Please refer to Figure 2 、 Figure 6 and Figure 7 , during the thrombectomy, when the thrombus-removing stent 21 is located in the blood vessel and the cutting portion 211 is located at the distal end of the thrombus, since the distal segment 221 is flexible, when the distal segment 221 is radially opposite to the thrombus attached to the blood vessel wall, the distal segment 221 can be adaptively bent. Therefore, the distal segment 221 will not lift the proximal end 2112 of the cutting portion 211 towards the direction of the central axis of the blood vessel due to its own rigidity, thereby increasing the adhesion of the proximal end 2112 of the cutting portion 211. The proximal segment 222 extends proximally from the connection between the distal segment 221 and the proximal segment 222, so as to facilitate the operator to operate the pulling rod 22. As can be understood by those skilled in the art, the pulling rod 22 also has a certain rigidity, so that the pulling rod 22 has axial support, thereby being able to provide a pushing force to the thrombus-removing stent 21. For example, the pulling rod 23 provides a pushing force during the process of the thrombus-removing stent 21 moving out of the delivery sheath 23, so as to avoid the thrombus-removing stent 21 being driven to synchronous movement by the delivery sheath 23 due to the frictional force between the thrombus-removing stent 21 and the inner wall of the delivery sheath 23, thereby enabling the relative movement between the thrombus-removing stent 21 and the delivery sheath 23, and enabling the thrombus-removing stent 21 to be loaded or released by the delivery sheath 23.

[0049] Please refer to Figure 6In the embodiment, the distal section 221 is provided with a plurality of axial cutting grooves 2211, and the openings of the plurality of cutting grooves 2211 are radially outward (i.e., the direction towards the blood vessel wall when the pull rod 22 is located in the blood vessel), so that the distal section 221 is flexible, and when the distal section 221 is radially opposite to the thrombus, the distal section 221 can be adaptively bent. The distal section 221 has a continuous side wall in the axial direction thereof, which extends from the distal end of the distal section 221 to the proximal end of the distal section 221, so that the distal section 221 has flexibility and also has certain rigidity, thereby enabling the pull rod 22 to provide a pushing force for the thrombus-removal stent 21.

[0050] Please refer to Figure 8 In another embodiment, the pull rod 22 comprises a distal section 221 and a proximal section 222 connected in sequence from distal to proximal, the distal end of the distal section 221 is connected to the proximal end of the cutting portion 211, the proximal end of the distal section 221 is connected to the proximal section 222, and the distal end of the distal section 221 is radially offset relative to the proximal end of the distal section 221. The distance between the distal end of the distal section 221 and the proximal end portion 2112 (see Figure 2 ) of the cutting portion 211 in the radial direction of the thrombus-removal stent 21 is less than the distance between the proximal end of the distal section 221 and the proximal end portion 2112. Please refer to Figure 2 , Figure 8 and Figure 9 In the projection plane A perpendicular to the axis of the thrombus-removal stent 21, the projection B of the cutting portion 211 is annular, and the projection C of the proximal end of the distal section 221 is located in the projection B of the cutting portion 211. The proximal section 222 extends axially from the connection with the distal section 221 to the proximal end.

[0051] In the process of using the thrombus-removal device 2 to remove the thrombus, the thrombus-removal stent 21 and the distal section 221 are first placed at the distal end of the thrombus. Due to the fact that the distal end of the distal section 221 is radially offset relative to the proximal end of the distal section 221, the distance between the distal end of the distal section 221 and the proximal end portion 2112 of the cutting portion 211 in the radial direction of the thrombus-removal stent 21 is less than the distance between the proximal end of the distal section 221 and the proximal end portion 2112, and in the projection plane A perpendicular to the axis of the thrombus-removal stent 21, the projection B of the cutting portion 211 is annular, and the projection C of the proximal end of the distal section 221 is located in the projection B of the cutting portion 211, so that the structure formed by the distal section 221 and the proximal section 222 can adapt to the convex structure of the inner wall of the blood vessel and the thrombus formation, and will not cause the distal section 221 and the cutting portion 211 to be lifted in the direction close to the central axis of the blood vessel, thereby increasing the wall-adhesion of the proximal end portion 2112 of the cutting portion 211.

[0052] Please refer to Figure 2The thrombus extraction device 2 further comprises a delivery sheath 23, which is a tubular structure, and the delivery sheath 23 is slidably sleeved on the pull rod 22 for loading the thrombus extraction stent 21 and carrying the thrombus extraction stent 21 to be delivered in the blood vessel of the patient. When the thrombus extraction stent 21 is loaded, the delivery sheath 23 is moved relative to the thrombus extraction stent 21 to sleeve the delivery sheath 23 on the thrombus extraction stent 21, so that the thrombus extraction stent 21 is radially compressed to the loading size and is loaded in the inner cavity of the delivery sheath 23, so as to be delivered in the blood vessel of the patient. In the process of loading the thrombus extraction stent 21, the pull rod 22 exerts a pulling force on the thrombus extraction stent 21, so that the thrombus extraction stent 21 can be compressed and loaded in the inner cavity of the delivery sheath 23. When the delivery sheath 23 delivers the thrombus extraction stent 21 to the target site (for example, the cutting part 211 is located at the distal end of the thrombus), the delivery sheath 23 is slid proximally relative to the thrombus extraction stent 21 or the thrombus extraction stent 21 is pushed out of the delivery sheath 23 by the pull rod 22, so as to release the thrombus extraction stent 21 from the delivery sheath 23, thereby releasing the radial compression constraint of the delivery sheath 23 on the thrombus extraction stent 21. In the process of sliding the delivery sheath 23 proximally to release the thrombus extraction stent 21, the pull rod 22 exerts a pushing force on the thrombus extraction stent 21, which is directed distally, to avoid the thrombus extraction stent 21 from being driven by the delivery sheath 23 to move synchronously with the delivery sheath 23, so that the thrombus extraction stent 21 can move relative to the delivery sheath 23 to be released from the inner cavity of the delivery sheath 23. After the radial constraint of the delivery sheath 23 on the thrombus extraction stent 21 is released, the thrombus extraction stent 21 can be radially self-expanded to a radially expanded state, so that the cutting part 211 is in contact with the blood vessel wall. When the driving force is exerted on the thrombus extraction stent 21 by the pull wire 41 and the pull rod 22 to move the thrombus extraction stent 21 proximally, the cutting part 211 can cut the thrombus on the blood vessel wall.

[0053] Referring to Figure 2 and Figure 4 In an embodiment, after the distal end of the pull wire 41 is connected with the second interval segment 212 of the thrombus extraction stent 21, the proximal end of the pull wire 41 extends proximally out of the body along the inner cavity of the delivery sheath 23, so as to facilitate the operator to operate the pull wire 41, thereby exerting the driving force on the thrombus extraction stent 21 through the pull wire 41.

[0054] In another embodiment, after the distal end of the pull wire 41 is connected with the second interval segment 212 of the thrombus extraction stent 21, the proximal end of the pull wire 41 can extend proximally out of the body along the inner cavity of the pull rod 22.

[0055] Referring to Figure 2 and Figure 10 The thrombus extraction device 2 further comprises a handle 24, and the proximal end of the pull rod 22 is fixedly connected with the handle 24. The pull wire 41 slidably passes through the inside of the handle 24, and the proximal end of the pull wire 41 is led out of the proximal end of the handle 24.

[0056] Specifically, referring toFigure 10 The handle 24 in the embodiment comprises a holding member 241 and a connecting head 242.

[0057] Please refer to Figure 10 The holding member 241 is a hollow columnar structure, and extends in the axial direction for a certain length to facilitate the operator to hold it. The distal end of the holding member 241 is connected to the connecting head 242. The connecting head 242 has a shaft hole extending in the axial direction and penetrating through the proximal end and the distal end of the connecting head 242. The connecting head 242 and the holding member 241 can be connected by screwing, buckling or other connection methods. When the connecting head 242 is connected to the holding member 241, the shaft hole of the connecting head 242 and the inner cavity of the holding member 241 are in communication, and the traction line 41 passes through the handle 24 along the shaft hole of the connecting head 242 and the inner cavity of the holding member 241.

[0058] Please refer to Figure 2 and Figure 10 The proximal end of the traction rod 22 is fixedly connected to the connecting head 242 or the holding member 241.

[0059] Please refer to Figure 10 The handle 24 is detachably connected to the delivery sheath 23 through the connecting head 242. In an embodiment, the connecting head 242 is connected to the distal end of the delivery sheath 23 by screwing. When the connecting head 242 is separated from the delivery sheath 23, the delivery sheath 23 can slide relative to the stentriever 21 under the action of an external force to load or release the stentriever 21. During the stentriever process, when the connecting head 242 is connected to the delivery sheath 23, the delivery sheath 23 has an axial spacing between the distal end and the proximal end of the stentriever 21, so that the stentriever 21 is located outside the delivery sheath 23.

[0060] During the stentriever process, the operator drives the stentriever 21 to move proximally in the blood vessel through the traction line 41, and at the same time, the operator synchronously drives the handle 24 to move proximally. Since the handle 24 is connected to the delivery sheath 23, the delivery sheath 23 is driven by the handle 24 to move proximally synchronously with the handle 24, so that the delivery sheath 23 always maintains an axial spacing between the distal end and the proximal end of the stentriever 21, thereby avoiding the distal end of the delivery sheath 23 compressing the stentriever 21 and affecting the stentriever effect. Moreover, the part of the traction line 24 located in the delivery sheath 23 is isolated from the blood vessel wall during the stentriever process, so that the blood vessel wall can be prevented from being damaged by the traction line 23.

[0061] In an embodiment, the proximal end of the pull wire 41 is fixedly connected with the handle 24, and the pull wire 41 is in a taut state. For example, the pull wire 41 is fixedly connected with the holding member 241, and the pull wire 41 is in a taut state. Alternatively, the pull wire 41 is fixedly connected with the delivery sheath 23, and the pull wire 41 is in a taut state when the delivery sheath 23 is connected with the connecting head 242 of the handle 24. During the thrombus extraction process, the operator drives the handle 24 to move proximally, and the handle 24 drives the pull rod 22 and the pull wire 41 to move simultaneously, so as to drive the thrombus extraction stent 21 to move in the blood vessel to cut the thrombus.

[0062] The technical features of the above-described embodiments can be combined in any manner. For the sake of brevity, not all possible combinations of the technical features in the above-described embodiments are described, but it should be understood that any combination of the technical features is within the scope of the present disclosure as long as there is no contradiction.

[0063] The above only describes the preferred embodiments of the present application, and of course cannot limit the scope of the present application. Any equivalent changes made according to the claims of the present application are still within the scope of the present application.

Claims

1. A thrombus removal device, characterized in that, include: A thrombectomy stent has an inner cavity and includes a proximal cutting portion with an opening communicating with the inner cavity. The cutting portion includes a distal end and a proximal end. The thrombectomy stent is radially compressible and self-expanding. Under the action of a restraining force, the thrombectomy stent can be radially compressed to the loading size, and after the restraining force is removed, the thrombectomy stent can self-expand to a radially extended state. A pull rod is connected to the proximal end; The traction line is a flexible component, and its distal end is connected to the thrombectomy bracket. The connection point between the traction line and the thrombectomy bracket is located at the distal end of the distal end or the axial distance between the connection point and the distal end is zero.

2. The thrombectomy device as described in claim 1, characterized in that, When the traction line is under tension, an acute angle X is formed between a segment of the traction line near its distal end and a straight line extending axially along the retrieval bracket and passing through the distal end of the retrieval bracket and the proximal end of the cutting portion. The acute angle X is in the range of [0°, 18°].

3. The thrombectomy device as described in claim 1, characterized in that, The distal end of the traction line is connected to the thrombectomy bracket, and the traction line extends from the inner cavity of the thrombectomy bracket towards the proximal end.

4. The thrombectomy device as described in claim 1, characterized in that, The thrombectomy stent has a mesh structure, the distal end of the traction line is connected to the thrombectomy stent, and the traction line is wound around the mesh of the thrombectomy stent and extends from the inner cavity of the thrombectomy stent towards the proximal end.

5. The thrombectomy device according to any one of claims 1 to 4, characterized in that, The thrombectomy stent comprises a first segment, a second segment, and a third segment from far to near. The first segment is conical, and the proximal end of the first segment with a larger diameter is connected to the second segment. The second segment is cylindrical, and the end of the second segment furthest from the first segment is connected to the third segment. The cutting part is located within the third segment, and the connection point is located within the second segment.

6. The thrombectomy device as described in claim 1, characterized in that, The proximal end of the cutting section is a pointed structure pointing proximally.

7. The thrombectomy device as described in claim 1, characterized in that, The traction rod includes a distal segment and a proximal segment connected sequentially from far to near. The distal segment is connected to the proximal end of the cutting part. The distal segment is flexible and can be bent and deformed when subjected to radial force. The proximal segment extends axially from the point of connection with the distal segment toward the proximal end.

8. The thrombectomy device as described in claim 7, characterized in that, The distal segment has multiple axially arranged grooves, and the openings of the multiple grooves are radially outward.

9. The thrombectomy device as described in claim 1, characterized in that, The traction rod includes a distal segment and a proximal segment connected sequentially from far to near. The distal end of the distal segment is connected to the proximal end of the cutting portion, and the proximal end of the distal segment is connected to the proximal segment. In the radial direction of the thrombectomy bracket, the distance between the distal end of the distal segment and the proximal end of the cutting portion is less than the distance between the proximal end of the distal segment and the proximal end of the cutting portion. In a projection plane perpendicular to the axis of the thrombectomy bracket, the projection of the cutting portion is annular, and the projection of the proximal end of the distal segment is located within the projection of the cutting portion. The proximal segment extends axially from the point of connection with the distal segment towards the proximal end.

10. The thrombectomy device as described in claim 1, characterized in that, The thrombectomy device further includes a handle, the proximal end of the traction rod is fixedly connected to the handle, the proximal end of the traction line slidably passes through the interior of the handle and exits from the proximal end of the handle; or, the proximal end of the traction line is fixedly connected to the handle, and the traction line is in a taut state.

11. The thrombectomy device as described in claim 10, characterized in that, The thrombectomy device further includes a delivery sheath, which is slidably fitted over the traction rod. The delivery sheath is detachably connected to the handle. The proximal end of the traction line extends from the inner cavity of the delivery sheath into the interior of the handle and exits through the proximal end of the handle. When the delivery sheath is separated from the handle, it can slide relative to the thrombectomy bracket under external force, thereby loading or releasing the thrombectomy bracket. When the handle is connected to the delivery sheath, there is an axial gap between the distal end of the delivery sheath and the proximal end of the thrombectomy bracket.

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