Basket-type thrombectomy device

Abstract

The present invention relates to the field of medical device technology, and discloses a basket-type thrombus removal device. The device comprises: a distal filter disc, a proximal recovery disc and at least one intermediate thrombus removal disc that can be radially elastically expanded and have a mesh structure; the distal filter disc, the intermediate thrombus removal disc and the proximal recovery disc are coaxially connected in sequence; in a naturally unfolded state, the intermediate thrombus removal disc is in the shape of a flat disc, and the diameter of the intermediate thrombus removal disc is greater than the diameter of the distal filter disc. The embodiment of the present invention can provide a fast, safe and effective thrombus removal method for the treatment of embolism with large size and large amount of thrombus, such as pulmonary embolism, thereby helping to improve the treatment effect of patients with acute medium and high-risk pulmonary embolism.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a basket-type thrombus removal device. Background Art

[0002] Pulmonary embolism (PE), a clinical pathophysiological syndrome (PE) in which various emboli in the systemic circulation break off and block the pulmonary artery and its branches, causing pulmonary circulation disorders, is one of the three most fatal cardiovascular diseases along with myocardial infarction and stroke. The most common pulmonary embolus is a blood clot, and pulmonary embolism caused by a blood clot is also called pulmonary thromboembolism (PTE). Today, intravascular interventional therapy has gradually become a trend in the treatment of intravascular diseases, but there is currently a lack of effective interventional treatment methods for the treatment of patients with acute pulmonary embolism. The products currently on the market for the treatment of vascular embolism are mainly aimed at clinical applications with small blood vessel diameters and small amounts of thrombi, such as intracranial arteries, coronary arteries, and lower limb arteries. However, pulmonary artery treatment faces the problem of large blood vessel diameters and large amounts of thrombi, and other existing intravascular thrombectomy products are not applicable or have very low effectiveness. In addition, current interventional products are mainly based on thrombolytic catheter therapy, which makes it difficult to effectively solve the rapid removal of large amounts of thrombi. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a basket-type thrombus removal device, which aims to provide a fast, safe and effective thrombus removal method for the treatment of embolism with large size and large amount of thrombus, such as pulmonary embolism, so as to improve the treatment effect of patients with acute medium and high risk pulmonary embolism.

[0004] To solve the above technical problems, the embodiments of the present invention provide a basket-type thrombus removal device, comprising: a distal filter disc that can elastically expand radially and has a mesh structure, a proximal recovery disc, and at least one intermediate thrombus removal disc;

[0005] The distal filtering disc, the intermediate thrombus removal disc and the proximal recovery disc are coaxially connected in sequence;

[0006] In a naturally expanded state, the intermediate embolus removal disc is in the shape of a flat disc, and the diameter of the intermediate embolus removal disc is greater than the diameter of the distal filtering disc.

[0007] Compared with the prior art, the basket-type thrombus removal device of the present invention comprises a distal filter disc, an intermediate thrombus removal disc and a proximal recovery disc which are radially elastically expandable, have a mesh structure and are coaxially connected in sequence. In the naturally unfolded state, the intermediate thrombus removal disc is in the shape of a flat disc, and the diameter of the intermediate thrombus removal disc is larger than the diameter of the distal filter disc. Therefore, when the basket-type thrombus removal device is delivered to the thrombus position and fully opened, the intermediate thrombus removal disc can cut up the softer thrombus and collect it in the intermediate thrombus removal disc by relying on its own strong supporting force, and squeeze the harder thrombus between itself and the blood vessel wall, so that it is pulled out of the body when the thrombus removal device is recovered. The distal filter disc can prevent small pieces of thrombus from escaping to the distal blood vessel. When the basket-type thrombus removal device is recovered, the proximal recovery disc can play a guiding role, so as to facilitate the recovery of the entire thrombus removal device into the outer sheath. Therefore, the basket-type thrombus removal device of this embodiment can quickly, effectively and safely remove thrombi with large blood vessel size and large thrombus volume, thereby providing a beneficial solution for the treatment of acute medium- and high-risk pulmonary embolism.

[0008] As an embodiment, in the naturally expanded state, the axial thickness of the distal filter disc is greater than or equal to the axial thickness of the intermediate thrombus removal disc.

[0009] As an embodiment, in the naturally expanded state, the diameter of the intermediate thrombectomy disc is 10% to 100% larger than the diameter of the blood vessel to which it is applied.

[0010] As an embodiment, in the naturally expanded state, the proximal end of the proximal recovery disc is conical, and the distal end of the proximal recovery disc is cylindrical.

[0011] As an embodiment, the distal filter disc, the intermediate thrombus removal disc and the proximal recovery disc are all woven from superelastic wire, and the weaving density of at least one connecting section between the discs is greater than the weaving density of the disc body of each disc;

[0012] Optionally, the number of the intermediate embolus removal discs is greater than one, and the diameter of each intermediate embolus removal disc decreases gradually from the proximal end to the distal end.

[0013] As an embodiment, the distal filter disc, the intermediate thrombus removal disc and the proximal recovery disc are all woven integrally from superelastic wire, and at least one mesh wire woven into each of the discs is a developing wire.

[0014] As an embodiment, the number of the developing wires is greater than 1, and the developing wires are evenly distributed on the disk along the circumferential direction.

[0015] As an embodiment, the developing wire is an elastic metal wire with developing performance; or

[0016] The developing wire comprises an elastic braided wire and at least one winding wire with developing performance wound around the elastic braided wire;

[0017] Optionally, the number of strands of the winding wire is 2; or

[0018] The developing wire comprises: a non-developing wire segment and a developing wire segment which are integrally connected, and the developing wire segment is at least distributed at a circumferential position of each of the disks.

[0019] As an embodiment, the developing wire comprises: a developing core wire and an elastic shell; the elastic shell is coated on the developing core wire;

[0020] Optionally, the diameter of the developing core wire is greater than one thousandth of an inch.

[0021] As an embodiment, the device further comprises: a push tube and a conical head; the proximal end of the proximal recovery disc is fixedly connected to the distal end of the push tube;

[0022] The distal end of the distal filter disc is fixedly connected to the proximal end of the conical head. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. It can be understood that the drawings in the following description are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0024] Figure 1 A schematic diagram of the structure of a basket-type thrombus removal device provided in one embodiment of the present invention;

[0025] Figure 2 A schematic diagram of the distribution of developing filaments on a disc provided in an embodiment;

[0026] Figure 3 A schematic diagram of the three-dimensional distribution of developing filaments provided by an embodiment;

[0027] Figure 4 A schematic diagram of distribution of developing filaments on a disc provided in yet another embodiment;

[0028] Figure 5 A schematic diagram of three-dimensional distribution of developing filaments provided in yet another embodiment;

[0029] Figure 6 A schematic diagram of a winding structure of a developing wire provided by an embodiment;

[0030] Figure 7 A schematic diagram of a winding structure of a developing wire provided in yet another embodiment;

[0031] Figure 8 A schematic diagram of the structure of a developing filament provided in yet another embodiment;

[0032] Fig. 9 A schematic diagram of the structure of a connecting section of a basket-type thrombus removal device provided in an embodiment before being stretched;

[0033] Fig.10 A schematic diagram of the structure of a basket-type thrombus removal device provided in an embodiment after the connecting section is stretched;

[0034] Fig.11 A schematic diagram of the relationship between the diameters of multiple intermediate thrombus removal discs of a basket-type thrombus removal device provided in one embodiment;

[0035] Figure 12 to Figure 14 A schematic diagram of the release state of multiple intermediate thrombus removal discs of a basket-type thrombus removal device provided by an embodiment;

[0036] Figures 15 to 17 Schematic diagram of the release and withdrawal of the basket-type thrombus removal device according to an embodiment of the present invention.

[0037] In the figure: a basket-type thrombus removal device 1, a distal filtering disc 10, an intermediate thrombus removal disc 11, a proximal recovery disc 12, a conical head 13, a push tube 14, a developing wire 15, an elastic braided wire 150, a winding wire 151, an elastic shell 152, a developing core wire 153, a connecting section 16, an outer sheath 2, a blood vessel 3, and a thrombus 4. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it can be understood by those skilled in the art that in the embodiments of the present invention, many technical details are provided to enable readers to better understand the present invention. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present invention can be implemented.

[0039] Unless otherwise specified, the proximal end and distal end mentioned in the present invention have the same meaning in terms of direction, that is, in the use state, the distal end is the end away from the operator, and the proximal end is the end close to the operator. The operator controls the thrombus removal device at the proximal end.

[0040] The embodiment of the present invention provides a basket-type thrombus removal device, which is particularly suitable for breaking and removing thrombi formed in pulmonary arteries. However, it is not limited thereto. It should be understood that the thrombus removal device of this embodiment is also suitable for removing thrombi in other blood vessels with large sizes and large amounts of thrombi. Figures 1 to 14As shown, the basket-type thrombus removal device 1 includes: a distal filter disc 10 that can be radially elastically expanded and has a mesh structure, a proximal recovery disc 12, and at least one intermediate thrombus removal disc 11; the distal filter disc 10, the intermediate thrombus removal disc 111, and the proximal recovery disc 12 are coaxially connected in sequence; in the naturally expanded state, the intermediate thrombus removal disc 11 is in the shape of a flat disc, and the diameter of the intermediate thrombus removal disc 11 is greater than the diameter of the distal filter disc 10. In a specific embodiment of the present invention, the basket-type thrombus removal device 1 may also include a push tube 14 and a conical head 13, the proximal end of the proximal recovery disc 12 is fixedly connected to the distal end of the push tube 14, and the distal end of the distal filter disc 10 is fixedly connected to the proximal end of the conical head 13. The structure of each component and the positional relationship, connection relationship, and function between them are described one by one below.

[0041] Optionally, in this embodiment, the distal filter disc 10, the intermediate thrombus removal disc 11 and the proximal recovery disc 12 are all woven from superelastic wire. As an example but not a limitation, the distal filter disc 10, the intermediate thrombus removal disc 11 and the proximal recovery disc 12 can be woven from superelastic nickel-titanium alloy wire, the wire diameter of the nickel-titanium alloy wire can be 0.05-0.25 mm, the woven mesh can be a rhombus, a rhombus-like or an equilateral quadrilateral structure, the woven mesh shape of each disc can be the same or different, the mesh size of the distal filter disc 10 can be smaller than the mesh size of the intermediate thrombus removal disc 11, so that small pieces of thrombus can be filtered and intercepted, and the thrombus broken by the intermediate thrombus removal disc can be prevented from escaping to the distal blood vessel. In the processing of the basket-type thrombus removal device, the coaxially connected and integrally woven distal filter disc 10, the intermediate thrombus removal disc 11 and the proximal recovery disc 12 can be obtained by mold weaving and heat treatment finalization. The distal end of the distal filter disc 10 is fixedly connected to the proximal end of the conical head 13, and the proximal end of the proximal recovery disc 12 is fixedly connected to the distal end of the push tube 14. During use, the delivery, release and recovery of the basket-type thrombus removal device are controlled by operating the push tube 14 and the outer sheath tube used in conjunction. This embodiment does not impose any restrictions on the mesh material, diameter size, and processing method and process of each disc of the basket-type thrombus removal device.

[0042] The intermediate thrombectomy disc 11 is mainly used to break up and capture blood clots. Optionally, in this embodiment, in the naturally expanded state, the diameter of the intermediate thrombectomy disc 11 is 10% to 100% larger than the diameter of the applied blood vessel, so that the intermediate thrombectomy disc 11 has better supporting force and will not damage the blood vessel. Preferably, the diameter of the intermediate thrombectomy disc 11 is 20% to 30% larger than the diameter of the applied blood vessel. Specifically, the diameter of the intermediate thrombectomy disc 11 can be designed according to the diameter of the pulmonary artery blood vessel, so that the diameter of the intermediate thrombectomy disc after full expansion is 20% larger than the diameter of the pulmonary artery blood vessel, but not more than 30% of the diameter of the pulmonary artery blood vessel, so that the supporting force of the intermediate thrombectomy disc is sufficient to break up and capture most types of blood clots, and can better protect the blood vessel from damage. In this embodiment, the middle thrombectomy disk 11 can be a regularly symmetrical structure, so that the disk surface of the middle thrombectomy disk 11 is perpendicular or approximately perpendicular to the central axis, that is, the middle thrombectomy disk 11 is a chamfered cylinder, and the overall shape is very flat, so that it has a strong radial supporting force. On the one hand, it can engage with the thrombus or cut the thrombus during the elastic opening process. On the other hand, when the net basket type thrombus removal device is recovered, some harder thrombi can be squeezed between it and the blood vessel wall and taken out of the body, thereby obtaining a better thrombus removal effect.

[0043] The distal filter disc 10 is used to filter and intercept the broken thrombi flowing to the distal end during the thrombus removal process. Optionally, in this embodiment, in the naturally expanded state, the diameter of the distal filter disc 10 can be 1 to 3 mm smaller than the diameter of the adjacent intermediate thrombus removal disc 11. For example, the diameter of the distal filter disc 10 is 1 mm, 2 mm or 3 mm smaller than the diameter of the adjacent intermediate thrombus removal disc 11, so that the basket-type thrombus removal device conforms to the characteristic of vascular anatomy that the diameter of the blood vessel becomes smaller as it moves distally. In addition, the axial thickness of the distal filter disc 10 is greater than or equal to the axial thickness of the intermediate thrombectomy disc 11. For example, the axial thickness of the distal filter disc 10 may be 1 to 3 times the axial thickness of the intermediate thrombectomy disc 11. For example, the axial thickness of the distal filter disc 10 is 2 times or 3 times the axial thickness of the intermediate thrombectomy disc 11. Compared with the flat structure of the intermediate thrombectomy disc 11, the overall shape of the distal filter disc 10 is more like an ellipsoid, and the long axis direction of the distal filter disc 10 is perpendicular to the axial direction of the basket-type thrombus removal device 1. Therefore, the radial supporting force of the distal filter disc 10 is smaller than that of the intermediate thrombectomy disc 11, and it is not easy to damage the distal blood vessel wall. At the same time, its larger axial thickness can also better intercept the thrombus that escapes from the filter.

[0044] The arrangement of the proximal recovery disc 12 facilitates the smooth recovery of the basket-type thrombus removal device 1 into the outer sheath. Optionally, in this embodiment, in the naturally expanded state, the proximal end of the proximal recovery disc 12 is approximately conical, and the distal end of the proximal recovery disc 12 is approximately cylindrical. In other words, the curvature radius of the proximal side arc of the proximal recovery disc 12 is larger than that of the distal side, for example, Figure 1 As shown, the proximal surface of the proximal retrieval disc 12 is umbrella-shaped, thereby reducing the resistance during retrieval.

[0045] On the basis of the above-mentioned embodiments, further, in this embodiment, the basket-type thrombus removal device 1 also includes a developing structure, so as to help the doctor clearly observe the position and three-dimensional shape of the basket-type thrombus removal device 1 through X-ray equipment during the operation, so as to achieve a better surgical effect. Specifically, in the basket-type thrombus removal device 1, at least one mesh wire woven into each disc is a developing wire. Preferably, the multiple strands of mesh wire woven into each disc are replaced with developing wires. The multiple strands of developing wires can be evenly distributed on each disc along the circumferential direction, or randomly distributed on each disc. In one example, as Figures 2-3 As shown, in the basket-type thrombus removal device 1, four strands of mesh woven into the distal filter disc 10, the middle thrombus removal disc 11, and the proximal recovery disc 12 are replaced with developing wires. Furthermore, the four developing wires are evenly distributed on each disc along the circumferential direction. When observed perpendicular to the disc surface, any two adjacent developing wires are distributed at an angle of about 90°, so that during surgery, it can be observed from any angle whether the disc is fully opened and whether it interacts with the thrombus. In another example, as Figures 4-5 As shown, in the basket-type thrombus removal device 1, 8 strands of mesh wires woven into the distal filter disc 10, the middle thrombus removal disc 11 and the proximal recovery disc 12 are replaced with developing wires. Optionally, the 8 developing wires are evenly distributed on each disc along the circumferential direction, so that the development of the basket-type thrombus removal device 1 can be more three-dimensional and clear. It can be understood that this embodiment does not impose any specific restrictions on the specific number of developing wires and the distribution method on the discs.

[0046] Optionally, the developing wire in the aforementioned embodiment may be an elastic metal wire with developing properties. As an example and not a limitation, the elastic metal wire may be made of metals or their alloys such as Pt (platinum), W (tungsten), Au (gold), etc., which have average elasticity but good developing properties, or may also be made of developing superelastic alloy materials. As an alternative example, the developing wire in the basket-type thrombus removal device 1 may include an elastic braided wire and at least one winding wire with developing properties wound around the elastic braided wire. Among them, the elastic braided wire may be a superelastic nickel-titanium alloy wire, and the material of the winding wire with developing properties may be Pt (platinum), W (tungsten), Au (gold), etc., or their alloys. Figure 6As shown, the developing wire 15 includes an elastic braided wire 150 and two winding wires 151 with developing performance wound around the elastic braided wire 150. In other examples, such as Figure 7 As shown, the developing wire 15 may include: an elastic braided wire 150 and two winding wires 151 with developing properties wound around the elastic braided wire 150. By winding multiple winding wires with developing properties, the amount of metal wire with developing properties can be reduced and the developing performance can be improved.

[0047] As another alternative, Figure 8 As shown, the developing wire 15 may include: a developing core wire 153 and an elastic shell 152, and the elastic shell 152 is coated on the developing core wire 153. Among them, the material of the developing core wire 153 may be Pt (platinum), W (tungsten), Au (gold) and other metals or their alloys, and the material of the elastic shell 152 may be a superelastic nickel-titanium alloy. Further, as an example but not a limitation, the diameter of the developing core wire 153 may be greater than one thousandth of an inch, but less than or equal to the diameter of other mesh wires. By coating the developing core wire 153 with an elastic shell, the developing wire 15 can not only have good developing performance, but also, compared with directly using a metal wire with general elasticity but developing performance as the developing wire, the elastic shell 152 can improve the elasticity of the developing wire, making its elasticity closer to other mesh wires, so that the net basket thrombus removal device 1 has good developing performance and good elasticity. As another alternative, the developing wire includes an integrally connected superelastic wire segment and a developing wire segment, and the developing wire segment is at least distributed in the circumferential position of each disc. This embodiment does not specifically limit the implementation method of the developing wire.

[0048] Optionally, based on the above embodiment, Fig. 9 As shown, the weaving density of at least one connecting section between the discs of the basket-type thrombus removal device 1 is greater than the weaving density of the disc body of each disc. For example, the weaving density of all connecting sections 16 between the distal filter disc 10, the intermediate thrombus removal disc 11 and the proximal recovery disc 12 is denser, while the weaving density of the disc body of each of the distal filter disc 10, the intermediate thrombus removal disc 11 and the proximal recovery disc 12 is relatively sparse, or only one or part of the connecting section 16 may have a denser weaving density, and no specific limitation is made here. Fig.10 , 11 As shown, they are schematic diagrams of the distance change between the disks of the basket-type thrombus removal device 1 before and after each connecting segment 16 is stretched. Therefore, the axial length of the basket-type thrombus removal device of this embodiment can be adjusted by stretching the length of the connecting segment with a denser weaving density, that is, the basket-type thrombus removal device has a variable length, so that during the operation, the basket-type thrombus removal device is suitable for embolism treatment of thrombi of different lengths, which is beneficial to improving the treatment effect.

[0049] Based on the above embodiments, Fig.11 As shown, the number of the intermediate thrombectomy discs 11 of the basket-type thrombus removal device 1 is greater than one. Furthermore, the diameter of each intermediate thrombectomy disc 11 decreases gradually from the proximal end to the distal end. For example, the basket-type thrombus removal device 1 may have three intermediate thrombectomy discs 11, and the diameter of each intermediate thrombectomy disc 11 decreases gradually from the proximal end to the distal end. The basket-type thrombus removal device of this embodiment can adapt to the tapered shape change of the blood vessel from proximal to distal, which is beneficial to protecting the blood vessel. And, as Figure 12 to Figure 14 As shown, during the operation, the doctor can also select the required thrombectomy basket length for the corresponding diseased blood vessel segment by controlling the number of released intermediate thrombectomy discs 11. This embodiment does not impose any specific restrictions on the specific number of intermediate thrombectomy discs and the relationship between the diameters of the intermediate thrombectomy discs.

[0050] Combined with Figures 15 to 17 The method and steps of using the basket-type thrombus removal device of the embodiment of the present invention are as follows:

[0051] In the interventional surgical treatment of thrombus removal, an instrument intervention channel is established in the femoral vein through a puncture needle, a puncture sheath, a guide wire, and angiography catheter. The catheter is introduced into the blocked part of the blood vessel through the intravascular intervention channel technology, and then selective angiography is performed to determine the location of the blood vessel where the thrombus is located. The replacement angiography catheter is a superhard guide wire (the guide wire is introduced and then the catheter is withdrawn). The matching outer sheath tube 2 catheter is introduced into the blood vessel 3 where the thrombus 4 is located through the guide wire. The basket-type thrombus removal device 1 of the embodiment of the present invention is taken out and enters the body through the outer sheath tube 2 until the thrombus 4 is judged to be in the middle part of the basket-type thrombus removal device 1 through imaging. The outer sheath tube 2 is withdrawn, and the basket-type thrombus removal device 1 is released at the thrombus 4. The X-ray imaging is used to judge whether each disc at the position of the thrombus 4 is fully opened and acts on the thrombus. It is left to stand for a period of time to ensure that the thrombus has enough time to fit with the opened disc. Then, the thrombus is collected into the outer sheath tube 2 by withdrawing the basket-type thrombus removal device 1, and finally removed from the body. During the thrombus removal process, the outer sheath 2 can also be sucked to assist in grabbing the thrombus and entering the catheter. Finally, the catheter is withdrawn from the body, the wound is sutured, and the operation is completed.

[0052] The basket-type thrombus removal device of this embodiment breaks and captures thrombi through the supporting force of the intermediate thrombus removal disc, and filters and intercepts escaped small pieces of thrombi through the distal filter disc, thereby quickly, safely and effectively removing thrombi with large blood vessel size and thrombus volume, and is particularly suitable for the treatment of acute medium- and high-risk pulmonary embolism. In addition, this embodiment replaces the mesh with developing wire woven into the basket-type thrombus removal device, so that it is very convenient to observe the position and three-dimensional shape of the basket-type thrombus removal device in the blood vessel, which can improve the convenience and success rate of surgical operation. In addition, the basket-type thrombus removal device of this embodiment can also adjust the length of the basket-type thrombus removal device by stretching the connecting section between the discs with a larger weaving density, or adjust the length of the thrombus removal device by controlling the number of released intermediate thrombus removal discs, so that the thrombus removal device can flexibly adapt to different thrombus lengths and improve the versatility of the thrombus removal device.

[0053] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present invention, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A basket-type thrombus removal device, characterized in that: include: A distal filter disc, a proximal recovery disc and at least one intermediate thrombus removal disc that can expand radially and elastically and have a mesh structure; The distal filtering disc, the intermediate thrombus removal disc and the proximal recovery disc are coaxially connected in sequence; In a naturally expanded state, the intermediate thrombus removal disc is in the shape of a flat disc, and the diameter of the intermediate thrombus removal disc is greater than the diameter of the distal filtering disc; The distal filter disc, the intermediate thrombus removal disc and the proximal recovery disc are all woven integrally from superelastic silk, and at least one mesh silk woven into each disc is a developing silk; the weaving density of at least one connecting section between the discs is greater than the weaving density of the disc body of each disc, so that the axial length of the basket-type thrombus removal device can be adjusted by stretching the length of the connecting section with a denser weaving density.

2. The basket-type thrombus removal device according to claim 1, characterized in that: In the naturally expanded state, the axial thickness of the distal filter disc is greater than or equal to the axial thickness of the intermediate thrombus removal disc.

3. The basket-type thrombus removal device according to claim 1, characterized in that: In a naturally expanded state, the diameter of the intermediate thrombectomy disc is 10% to 100% larger than the diameter of the blood vessel to which it is applied.

4. The basket-type thrombus removal device according to claim 1, characterized in that: In a naturally expanded state, the proximal end of the proximal retrieval disc is conical, and the distal end of the proximal retrieval disc is cylindrical.

5. The basket-type thrombus removal device according to claim 1, characterized in that: The number of the intermediate embolism removal discs is greater than one, and the diameter of each intermediate embolism removal disc decreases gradually from the proximal end to the distal end.

6. The basket-type thrombus removal device according to claim 1, characterized in that: The number of the developing wires is greater than 1, and the developing wires are evenly distributed on the disks along the circumferential direction.

7. The basket-type thrombus removal device according to claim 1, characterized in that: The developing wire is an elastic metal wire with developing performance.

8. The basket-type thrombus removal device according to claim 1, characterized in that: The developing wire comprises an elastic braided wire and at least one winding wire with developing performance wound around the elastic braided wire.

9. The basket-type thrombus removal device according to claim 8, characterized in that: The number of strands of the winding wire is 2.

10. The basket-type thrombus removal device according to claim 1, characterized in that: The developing wire comprises: a non-developing wire segment and a developing wire segment which are integrally connected, and the developing wire segments are at least distributed at the circumferential position of each disc.

11. The basket-type thrombus removal device according to claim 1, characterized in that: The developing wire comprises: a developing core wire and an elastic shell; the elastic shell covers the developing core wire.

12. The basket-type thrombus removal device according to claim 11, characterized in that: The developer core wire has a diameter greater than one thousandth of an inch.

13. The basket-type thrombus removal device according to any one of claims 1 to 12, characterized in that: The device also includes: a push tube and a conical head; The proximal end of the proximal recovery disc is fixedly connected to the distal end of the pushing tube; the distal end of the distal filter disc is fixedly connected to the proximal end of the conical head.

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