Thrombectomy device

Abstract

The present invention relates to the field of medical device technology, and discloses a thrombus removal device. The device comprises: a thrombus filtering net bag, a connecting bracket, and a thrombus fragmentation net bag; the thrombus filtering net bag, the connecting bracket, and the thrombus fragmentation net bag are all radially self-expanding bracket structures; the distal end of the thrombus filtering net bag is closed, and the proximal end is an open end that can be supported circumferentially on the inner wall of the blood vessel, and the open end is connected to the distal end of the connecting bracket; the distal end of the thrombus fragmentation net bag can be supported circumferentially on the inner wall of the blood vessel and is connected to the proximal end of the connecting bracket; the connecting bracket forms a thrombus capture area in the expanded state. The embodiments of the present invention can improve the success rate of thrombus removal in one go, while better preventing the escape of fragmented thrombi, thereby making thrombus removal more thorough.

Description

Technical Field

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

[0002] Intravascular thrombosis is a widespread systemic disease that can affect the upper and lower extremities, visceral vessels, and carotid arteries. When thrombosis occurs in the heart, it can cause myocardial infarction; in the brain, it can cause cerebral infarction; and in the lungs, it can cause pulmonary embolism. According to statistics, thrombotic diseases account for 51% of deaths worldwide, far exceeding deaths caused by cancer, infectious diseases, and respiratory diseases.

[0003] Currently, the main treatments for thrombosis include anticoagulant medication, interventional procedures, and surgery. For patients with mild symptoms, conservative treatment with anticoagulants is appropriate; however, for those who are unresponsive to medication, surgery is necessary. Compared to surgery, interventional therapy is less invasive and offers a faster recovery time, making it more acceptable to patients. However, the effectiveness of interventional therapy is often limited by the interventional device itself.

[0004] The inventors discovered that due to the diversity of thrombotic disease sites and the complexity of thrombus morphology, existing thrombus removal devices, such as thrombus removal stents and aspiration catheters, generally have the problems of difficulty in completely removing thrombi, low success rate of one-time thrombus removal, and the easy escape of fragmented thrombi and blocking distal branches. Summary of the Invention

[0005] In view of this, an object of an embodiment of the present invention is to provide a thrombus removal device to solve the problems of low success rate of one-time thrombus removal and easy omission of fragmented thrombi.

[0006] The embodiment of the present invention provides a thrombus removal device, comprising: a thrombus filtering net bag, a connecting bracket, and a thrombus crushing net bag;

[0007] The thrombus filtering net bag, the connecting stent and the thrombus crushing net bag are all radially self-expanding stent structures;

[0008] The distal end of the thrombus filtering net bag is closed, and the proximal end is an open end that can be supported on the inner wall of the blood vessel along the circumferential direction, and the open end is connected to the distal end of the connecting bracket;

[0009] The distal end of the thrombus-breaking net bag can be supported on the inner wall of the blood vessel along the circumferential direction and is connected to the proximal end of the connecting bracket;

[0010] The connecting stent forms a thrombus capturing area in the expanded state.

[0011] In addition, the thrombus filtering net bag, the connecting bracket and the thrombus crushing net bag are made of memory metal wire woven into one piece.

[0012] In addition, the thrombus removal device further comprises: a stent constricting ring;

[0013] The bracket constricting ring is sleeved on the connecting bracket.

[0014] In addition, the bracket contracting ring is a developing ring.

[0015] In addition, the connecting stent includes: a first stent segment located between the open end of the thrombus filtering net bag and the stent contraction ring, and a second stent segment located between the stent contraction ring and the thrombus breaking net bag;

[0016] The first stent segment comprises: a plurality of twisted rods formed by braiding the braided wires of the thrombus filter net bag at its open end, and the plurality of twisted rods are evenly spaced along the circumference of the open end of the thrombus filter net bag;

[0017] The second stent segment includes: a plurality of twisted rods woven from the braided wires of the thrombus-breaking net bag at its open end, and the plurality of twisted rods are evenly spaced along the circumference of the open end of the thrombus-breaking net bag.

[0018] In addition, the number of twisted rods of the second stent segment is an even multiple of the number of twisted rods of the first stent segment, and the thrombus-breaking net bag is formed by interweaving a plurality of metal wires, each metal wire having an even number of strands.

[0019] In addition, the thrombus filtering net bag is umbrella-shaped when unfolded, and the mesh density thereof gradually decreases from the distal end to the proximal end.

[0020] In addition, the thrombus-breaking net bag is a net bag unit, and the net bag unit is dome-shaped; or

[0021] The thrombus-breaking net bag comprises a plurality of net bag units sequentially connected from the distal end to the proximal end, each net bag unit is a smooth transition net bag structure with a large diameter in the middle and a small diameter at the end, and the proximal net bag unit is disc-shaped.

[0022] In addition, the thrombus removal device further comprises: a distal developing ring provided at the distal end of the thrombus filtering net bag and a proximal developing ring provided at the proximal end of the thrombus breaking net bag;

[0023] The distal development ring is also used to tighten and fix the metal wire at the distal end of the thrombus filter net bag;

[0024] The proximal developing ring is also used to tighten and fix the metal wire at the proximal end of the thrombus-breaking net bag.

[0025] In addition, the thrombus removal device further comprises: a guide head and a push tube;

[0026] The proximal end of the guide head is connected to the distal end of the distal developing ring.

[0027] The distal end of the pushing tube is connected to the proximal end of the proximal developing ring.

[0028] The thrombus removal device of the embodiment of the present invention automatically unfolds after being released to the distal end of the thrombus. When the thrombus removal device is withdrawn, the thrombus crushing net bag cuts and crushes the thrombus, and the crushed thrombus enters the thrombus filtering net bag through the thrombus capture area, thereby collecting the crushed thrombus more thoroughly into the sheath, which not only improves the success rate of thrombus removal in one time, but also makes it difficult for the crushed thrombus to escape, thereby facilitating more thorough removal of the thrombus. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. It can be understood that the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0030] Figure 1 A schematic structural diagram of a thrombus removal device provided in an embodiment of the present invention;

[0031] Figure 2 A schematic diagram of another structure of the thrombus removal device provided in an embodiment of the present invention;

[0032] Figure 3 A schematic structural diagram of the mesh density of the thrombus filtering net bag of the thrombus removal device provided in an embodiment of the present invention;

[0033] Figure 4 A schematic structural diagram of a twisted rod connecting a bracket of a thrombus removal device provided in an embodiment of the present invention;

[0034] Figure 5 A schematic diagram of the structure of the thrombus removal device and the delivery system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more apparent, various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will appreciate that many technical details are provided in various embodiments of the present invention to help readers better understand the present invention. However, even without these technical details and various variations and modifications based on the following embodiments, the technical solutions claimed in the present invention can still be implemented.

[0036] 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 thrombectomy device at the proximal end.

[0037] The embodiment of the present invention provides a thrombus removal device 1 for rapid removal of thrombi in blood vessels. Figure 5 For use with the delivery system shown, such as pre-loaded Figure 5 The delivery system is shown in the sheath 7. Figure 1 As shown, the thrombus removal device 1 comprises: a thrombus filtering net bag 10, a connecting stent 11 and a thrombus breaking net bag 12. The thrombus filtering net bag 10, the connecting stent 11 and the thrombus breaking net bag 12 are all radially self-expanding stent structures.

[0038] The distal end of the thrombus filter net bag 10 is closed, and the proximal end is an open end that can be supported on the inner wall of the blood vessel along the circumferential direction, and the open end is connected to the distal end of the connecting bracket 11. The thrombus filter net bag 10 can filter and collect broken thrombi.

[0039] The distal end of the thrombus-breaking net bag 12 can be circumferentially supported on the inner wall of the blood vessel and is connected to the proximal end of the connecting bracket 11. The thrombus-breaking net bag 12 can cut and break the thrombus into smaller thrombi, which can be easily collected into the thrombus filtering net bag.

[0040] The connecting bracket 11 forms a thrombus capturing area in the expanded state, into which the fragmented thrombus is filled and then collected into the thrombus filtering net bag 10 .

[0041] The thrombus filtering net 10, connecting bracket 11, and thrombus rupturing net 12 can be integrally woven from memory metal wire, resulting in each braided structure exhibiting excellent radial self-expansion and shape memory properties. It is understood that the thrombus filtering net 10, connecting bracket 11, and thrombus rupturing net 12 can also be manufactured using laser cutting, without specific limitation.

[0042] The thrombus filter net 10 can be made of multiple memory metal wires, such as nickel-titanium alloy wires, interwoven together. Specifically, a single metal wire can be woven into an umbrella-shaped net structure, with a smooth transition from the open end to the distal end. The thrombus filter net 10 has a large diameter at the open end, allowing it to adhere well to the inner wall of the blood vessel after expansion and move along the vessel wall. During the retraction process, the thrombus filter net 10 can collect fragmented thrombi along the inner wall of the vessel into the thrombus filter net, effectively preventing the leakage of thrombi. At the same time, blood flow can also pass through the thrombus filter net 10.

[0043] Optionally, the mesh density of the thrombus filtering net bag 10 can be gradually reduced from the distal end to the proximal end. Specifically, the thrombus filtering net bag 10 can be divided into multiple density segments in the axial direction, and the number of density segments of the thrombus filtering net bag 10 can be determined according to its length. Figure 3 As shown, the thrombus filtering net bag 10 is divided into three density segments along the axial direction, and the mesh density of the three density segments gradually decreases from the distal end to the proximal end. The mesh structure of the thrombus filtering net bag 10, which is dense at the distal end and sparse near the proximal end, can not only better hold the thrombus, but also reduce its sheathing resistance. In one example, the lengths of multiple density segments can gradually decrease from the distal end to the proximal end, that is, the density segment with the largest mesh density at the farthest end has the longest length, thereby better preventing the thrombus from escaping. This embodiment does not impose specific restrictions on the mesh density distribution structure of the thrombus filtering net bag. The mesh density of the thrombus filtering net bag 10 can be the same, or the lengths of different density segments can be the same, as long as the thrombus filtering effect and sheathing performance can be guaranteed. Compared with the thrombus filtering net bag 10 made by the laser cutting process, the weaving process can not only finely adjust the mesh density, but also has better softness and lower cost.

[0044] The thrombus removal device 1 further includes a distal imaging ring 3 disposed at the distal end of the thrombus filter net bag 10 for marking the distal end of the thrombus removal device 10. The distal imaging ring 3 can also be used to tighten and secure the metal wire at the distal end of the thrombus filter net bag 10, achieving two goals at once.

[0045] The thrombus-breaking net bag 12 and the thrombus-filtering net bag 10 are integrally woven with memory metal wires. The thrombus-breaking net bag 12 is woven with memory metal wires in an interlaced pattern, forming a diamond-shaped grid that facilitates cutting and breaking thrombi. This embodiment does not impose any specific restrictions on the grid shape.

[0046] like Figure 1 As shown, the thrombus-breaking net bag 12 can be a net bag unit, which is dome-shaped and has an open end, and the open end can be supported and attached to the inner wall of the blood vessel. The thrombus-breaking net bag 12 has a large diameter at the open end, and a smooth transition net bag structure is formed from the open end to the proximal end, with the diameter gradually decreasing.

[0047] The braided wires of the thrombus-breaking net bag 12 are gathered at the open end and woven into a plurality of twisted rods 110 evenly spaced along the circumference of the open end. The braided structure of the twisted rods 110 is as follows: Figure 4 shown.

[0048] The thrombus removal device 1 may further include a proximal developing ring 4 for marking the proximal end of the thrombus removal device. Meanwhile, the proximal metal wire of the thrombus-breaking net bag 12 can be fixed by the proximal developing ring 4 after being bundled.

[0049] In some examples, the thrombus fragmentation net bag 12 may include a plurality of net bag units sequentially connected from the distal end to the proximal end. The net bag unit adjacent to the connection bracket 11 is dome-shaped, and the net bag unit away from the connection bracket 11 is disc-shaped. Figure 2 As shown, the thrombus-breaking net bag 12 includes two net bag units, namely a distal net bag unit 120 connected to the proximal end of the connecting bracket 11 at the distal end, and a proximal net bag unit 121 connected to the proximal end of the distal net bag unit 120. The distal net bag unit 120 is a smooth transition net bag structure with a diameter gradually decreasing from the distal end to the proximal end, and the proximal net bag unit 121 is a smooth transition net bag structure with a large diameter in the middle and small diameters at both ends. Among them, the transition of the distal net bag unit 120 is relatively gentle, making the distal net bag unit 120 dome-shaped or umbrella-shaped. The transition of the proximal net bag unit 121 is relatively steep, making it a disc-shaped structure. The disc-shaped proximal net bag unit 121 can provide a thrombus cutting surface that is relatively perpendicular to the axis of the blood vessel when it is withdrawn, which can quickly break the thrombus. Multiple net bag units can break the thrombus multiple times, thereby achieving a better thrombus breaking effect. The thrombus-breaking net bag 12 can also collect some of the broken thrombi.

[0050] Please continue reading Figure 1 、 Figure 2 The thrombus removal device 1 may further include: a stent converging ring 2 , which is sleeved on the connecting stent 11 , that is, sleeved on the multiple twisted rods 110 after being converging.

[0051] Optionally, the stent constricting ring 2 is a developing ring, that is, the stent constricting ring 2 also has a developing function, which can be used to mark the position of the thrombus capture area.

[0052] The connecting bracket 11 includes: a first bracket segment located between the open end of the thrombus filtering net bag 10 and the bracket tightening ring 2, and a second bracket segment located between the bracket tightening ring 2 and the thrombus crushing net bag 12. The first bracket segment and the thrombus filtering net bag 10 form a three-dimensional diamond structure, and the second bracket segment and the net bag unit adjacent thereto form a three-dimensional diamond structure. The first support segment includes: a plurality of twisted rods 110 woven from the braided wires of the thrombus filtering net bag 10 at its open end, and the plurality of twisted rods 110 are evenly spaced along the circumference of the open end of the thrombus filtering net bag 10. The second support segment includes: a plurality of twisted rods 110 woven from the braided wires of the thrombus crushing net bag 12 at its open end, and the plurality of twisted rods 110 are evenly spaced along the circumference of the open end of the thrombus crushing net bag 12. As Figure 4 As shown, each twisted rod can be woven from 3 strands of braided wire, and each strand of braided wire can contain multiple metal wires.

[0053] Due to the constricting effect of the stent constricting ring 2, the connecting stent 11 forms a sparse stent structure with large diameters at both ends and a small diameter in the middle. The sparse stent structure forms a thrombus capture zone, which is convenient for the filling and entry of fragmented thrombi. In the expanded state, the twisted rods 110 of the connecting stent 11 will not adhere to the inner wall of the blood vessel, which can prevent the thrombus from being missed due to being squeezed on the blood vessel wall. During retraction, part of the thrombus can quickly enter the thrombus capture zone and be collected into the sheath that accommodates the thrombus removal device 1. An opening is formed between the multiple twisted rods 110 of the first stent segment, and the fragmented thrombus can smoothly enter the thrombus filter net bag 10 through the opening, and the thrombus filter net bag 10 brings all the thrombi into the sheath.

[0054] In some examples, the second stent segment may also adopt a mesh bag structure similar to the distal mesh bag unit 120. The use of a twisted rod structure not only simplifies the weaving process, but also provides a larger opening, which facilitates the entry of thrombus into the thrombus-breaking mesh bag.

[0055] The number of twisted rods in the second stent segment is an even multiple of the number of twisted rods in the first stent segment, and the thrombus-breaking net bag 12 is made of a plurality of strands of metal wire interwoven and woven, and each strand of metal wire has an even number of strands. For example, the number of twisted rods in the second stent segment is twice the number of twisted rods in the first stent segment. Figure 1 、 2 As shown, the first stent segment has 4 twisted rods, and the second stent segment has 8 twisted rods. The second stent segment has more twisted rods 110, which can form more braided nodes circumferentially at the open end of the thrombus-breaking net bag 12. The braided wires dispersed from the more braided nodes can be easily interwoven into the thrombus-breaking net bag 12. At the same time, each of any two interwoven braided wires of the thrombus-breaking net bag 12 has two braided wires. By combining multiple braided wires for interwoven weaving, it is not only convenient to weave a larger grid structure of the thrombus-breaking net bag to meet the thrombus-breaking requirements, but also the strength of the thrombus-breaking net bag can be increased, which is conducive to breaking harder thrombi. The first stent segment has fewer twisted rods, which can facilitate the thrombus filtering net bag to be placed in the sheath. The twisted rods of the first stent segment and the second stent segment can be arc-shaped rods.

[0056] The thrombectomy device 1 may further include a guide head 5 and a push tube 6. The distal end of the guide head 5 is a pointed tip, and the proximal end of the guide head 5 is connected to the distal end of the distal imaging ring 3, facilitating advancement of the thrombectomy device within the blood vessel. The distal end of the push tube 5 is connected to the proximal end of the proximal imaging ring 4. The push tube 5 can be manipulated to push the net bag structure of the thrombectomy device 1 out of the sheath or retract it into the sheath.

[0057] Combined with attachment Figure 1 、 5 The method and steps for using the thrombus removal device according to the embodiment of the present invention are as follows:

[0058] In the interventional surgical treatment for pulmonary embolism to remove thrombus, percutaneous puncture under local anesthesia is used to establish an instrument intervention channel in the femoral vein on the affected side. After the guide wire is sent to the position through the thrombus, the thrombus removal device of the embodiment of the present invention is guided through the guide wire and moved to the pulmonary embolism in the blood vessel cavity. The sheath of the thrombus removal device 1 is withdrawn to release the thrombus crushing net bag at the distal end of the thrombus. The thrombus removal device is withdrawn as a whole. During the withdrawal process, the thrombus is cut, squeezed and fragmented under the external force of the thrombus crushing net bag. As the thrombus removal device is withdrawn, the fragmented thrombus enters the thrombus capture area, and then enters the thrombus filtering net bag 10, and is finally taken out of the body.

[0059] Based on the above technical solutions, the embodiments of the present invention have at least the following advantages and positive effects:

[0060] The thrombus removal device 1 of the embodiment of the present invention automatically unfolds after being released to the distal end of the thrombus. When the thrombus removal device 1 is withdrawn, the thrombus crushing net bag cuts and crushes the thrombus. The crushed thrombus enters the thrombus capture area and is then caught along the blood vessel wall by the thrombus filtering net bag and then received into the sheath. This not only improves the success rate of thrombus removal in one time, but also makes it less likely to miss a thrombus, thereby allowing the thrombus to be removed more thoroughly.

[0061] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present invention, and that 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 thrombus removal device, characterized in that: include: Thrombus filtering net bag, connecting bracket and thrombus breaking net bag; The thrombus filtering net bag, the connecting stent and the thrombus crushing net bag are all radially self-expanding stent structures; The distal end of the thrombus filter net bag is closed, and the proximal end is an open end that can be supported on the inner wall of the blood vessel along the circumferential direction, and the open end is connected to the distal end of the connecting bracket; the thrombus filter net bag is umbrella-shaped when unfolded, and the mesh density gradually decreases from the distal end to the proximal end; The distal end of the thrombus-breaking net bag can be supported on the inner wall of the blood vessel along the circumferential direction and is connected to the proximal end of the connecting bracket; The connecting stent forms a thrombus capture area in the expanded state; The thrombus filtering net bag, the connecting bracket and the thrombus crushing net bag are made of memory metal wire woven into one piece; The thrombus removal device further comprises: a stent constricting ring; The bracket constricting ring is sleeved on the connecting bracket; The connecting bracket includes: a first bracket segment located between the open end of the thrombus filtering net bag and the bracket contraction ring, and a second bracket segment located between the bracket contraction ring and the thrombus breaking net bag; The first stent segment comprises: a plurality of twisted rods formed by braiding the braided wires of the thrombus filter net bag at its open end, and the plurality of twisted rods are evenly spaced along the circumference of the open end of the thrombus filter net bag; The second stent segment comprises: a plurality of twisted rods woven from the braided wires of the thrombus-breaking net bag at its open end, and the plurality of twisted rods are evenly spaced along the circumference of the open end of the thrombus-breaking net bag; The number of twisted rods in the second stent segment is an even multiple of the number of twisted rods in the first stent segment, and the thrombus-breaking net bag is formed by interlacing and weaving a plurality of metal wires, each metal wire having an even number of strands; The thrombus-breaking net bag is a net bag unit, and the net bag unit is dome-shaped; or The thrombus-breaking net bag comprises a plurality of net bag units sequentially connected from the distal end to the proximal end; wherein the net bag unit adjacent to the connecting bracket is dome-shaped, and the net bag unit away from the connecting bracket is disc-shaped.

2. The thrombus removal device according to claim 1, characterized in that: The bracket contracting ring is a developing ring.

3. The thrombus removal device according to claim 1, characterized in that: The thrombus removal device further comprises: a distal developing ring disposed at the distal end of the thrombus filtering net bag and a proximal developing ring disposed at the proximal end of the thrombus breaking net bag; The distal development ring is also used to tighten and fix the metal wire at the distal end of the thrombus filter net bag; The proximal developing ring is also used to tighten and fix the metal wire at the proximal end of the thrombus-breaking net bag.

4. The thrombus removal device according to claim 3, characterized in that: The thrombus removal device further includes: a guide head and a push tube; The proximal end of the guide head is connected to the distal end of the distal developing ring. The distal end of the pushing tube is connected to the proximal end of the proximal developing ring.

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