Thrombus remover

Abstract

The present invention provides a thrombus remover. The thrombus remover comprises a cylindrical self-expanding stent (1) with openings at both ends, a delivery guide wire (2) and an introduction sheath (3). The wall (11) of the self-expanding stent is composed of a hollow grid (12). The self-expanding stent (1) is divided into three parts along the length direction from the connection with the delivery guide wire (2): a proximal end (15), a middle section (14) and a distal end (13); the single grid area of ​​the grid of the middle section (14) is larger than the single grid area of ​​the distal end (13) and the proximal end (15). A smooth edge connecting rod (161) is arranged at the proximal edge of the self-expanding stent (1). The wall thickness of the self-expanding stent is 0.01-0.04 mm larger than the width of the connecting rod (16) at the non-proximal edge forming the grid (12).

Description

Technical Field

[0001] The present invention relates to medical equipment, and in particular to a thrombus remover. Background Art

[0002] Stroke is one of the main causes of death and disability in humans, and acute ischemic stroke (AIS) accounts for about 80% of all strokes. Studies have shown that there are about 7.5 million people with stroke in China, 2.5 million new strokes occur each year, and about 1.6 million people die, which seriously endangers human life. The key to treating AIS is to open blocked blood vessels as soon as possible and save the ischemic penumbra. Intravenous injection of recombinant tissue plasminogen activator (rt-PA) thrombolysis has been proven to be an effective method for treating AIS. The earlier the treatment time, the greater the benefit. However, it is limited by the strict time window and the requirements of indications and contraindications. The proportion of patients receiving thrombolytic therapy is relatively low, and most large vessel occlusive strokes are not sensitive to rt-PA. Only 6%-30% can achieve the purpose of recanalization of occluded blood vessels, and the benefit is limited. In order to solve the disadvantages of intravenous thrombolysis, domestic and foreign scholars have conducted clinical research on intravascular treatment methods. The results of the study showed that among the intravascular treatment methods, arterial thrombolysis can not only determine the actual location of the thrombotic lesion, but also prolong the time window. However, this treatment method still has a major drawback, that is, the thrombolysis time may be delayed due to operational reasons, and there is a risk of intervention-related complications, which increases the rate of symptomatic intracranial hemorrhage. Therefore, in clinical treatment, it is impossible to determine whether arterial thrombolysis is superior to intravenous thrombolysis.

[0003] In response to the drawbacks of clinical treatment, the research results of endovascular treatment based mainly on mechanical thrombectomy have been recognized by everyone. The results of many foreign randomized controlled studies have confirmed that in intracranial large vessel occlusive lesions, early implementation of endovascular interventional treatment represented by stent-type thrombectomy devices can significantly improve patient prognosis and increase the success rate of treatment. In particular, the design of the thrombectomy stent is the key to the success of clinical treatment.

[0004] At present, my country's research on thrombectomy stents has also achieved phased results.

[0005] The thrombectomy device disclosed in CN104840235A is composed of a conical spiral spring, the shape of which is controllable, and the principle of thrombus removal is to use a conical spiral spring to remove the thrombus in the blood vessel. However, this patented product is too idealistic, especially for in situ thrombus, which has a strong binding force with the blood vessel wall, and it is difficult to use this product to remove the thrombus.

[0006] The vascular thrombus removal device disclosed in the invention patent CN10662533A also has a spiral structure design, which makes it easier to remove thrombi. The thrombus removal device is a mesh or cage structure composed of multiple units, with longitudinal gaps on the side, and the longitudinal gaps extend spirally along the outer surface of the mesh or cage structure. However, thrombi may fall off during the thrombus removal process.

[0007] In order to avoid the problem of thrombus removal falling off, CN105476689A discloses a thrombus removal stent device, which includes a front thrombus removal stent and a rear protective stent, and the two successively remove the thrombus to prevent the thrombus from falling off. However, the patented product includes a thrombus removal stent and a protective stent, which greatly reduces the effective length of the thrombus removal stent, increases the overall length of the stent, and seriously affects the flexibility of the product. Also affecting the flexibility of the product is an intracranial vascular thrombus removal device and thrombus removal device disclosed in patent CN104068909A. Although the product has an inner concave or outer convex structure, which can fix the thrombus in the process of capturing and recovering the thrombus, the structure will seriously affect the outer diameter of the product after compression and gripping and the overall flexibility of the product, making it difficult to pass through tortuous blood vessels, and the outer convex structure may cause spasm of the blood vessels and cause damage to the blood vessels.

[0008] CN103284775B discloses an intracranial thrombus removal device, the distal end of which is controllable and can be closed to prevent the thrombus from falling off and blocking the distal blood vessels, and can also be opened to serve as a blood flow remodeling device. However, the product has a complex structure and operation, which affects the recanalization time of the blood vessels.

[0009] CN105997314A discloses a thrombus elimination system with composite functions, which includes a stent in the shape of a mesh tube that can be released and retracted from a delivery catheter and a stent delivery system. The stent can be completely withdrawn from the stent delivery system, repositioned and released, and can remove thrombi efficiently and multiple times; the stent coating section can also temporarily block blood flow to prevent small thrombi from blocking distal blood vessels. However, the stent of this patent adopts a weaving method, which results in a very small radial force of the stent. Grabbing thrombi can easily cause thrombi to rupture or fall off. The detached thrombi need to be repeatedly grasped, and ruptured smaller thrombi may cause blockage of the more distal blood vessels. At the same time, the stent coating section will increase the outer diameter of the stent after compression, affecting the flexibility of the entire system, making it more difficult to pass through more distant tortuous blood vessels.

[0010] Therefore, although there are many thrombectomy stent products in China, their product structures are complex, the operations are cumbersome, and the flexibility is poor. In clinical applications, blood clots are often difficult to remove or fall off, which cannot meet the clinical application requirements. Researching a thrombectomy stent device that is more suitable for clinical application is a hot spot and difficulty in current clinical research. Summary of the invention

[0011] The purpose of the present invention is to provide a thrombus remover. The thrombus remover can effectively improve the efficiency of thrombus capture, solve the problem in the prior art that vascular wall plaques and broken thrombus pieces are easy to fall off and cause re-embolism of distal blood vessels; at the same time, after being pressed and gripped, the outer diameter is small and the flexibility is high, so that it can quickly pass through curved blood vessels to reach the distant and thin blood vessels, thereby achieving the purpose of treatment.

[0012] For ease of description, the following description uses the terms “proximal end” and “distal end”, wherein the “proximal end” refers to an end close to an operator and the distal end refers to an end far from an operator.

[0013] To achieve the above-mentioned purpose, the present invention provides a thrombus remover, which includes a cylindrical self-expanding stent 1 with openings at both ends, a delivery guide wire 2 and an introduction sheath 3, wherein the wall 11 of the self-expanding stent is composed of a hollow grid 12, and the self-expanding stent 1 is divided into three parts along the length direction from the connection with the delivery guide wire 2: a proximal end 15, a middle section 14 and a distal end 13; the single grid area of ​​the grid of the middle section 14 is larger than the single grid area of ​​the distal end 13 and the proximal end 15, a smooth edge connecting rod 161 is arranged at the proximal edge of the self-expanding stent 1, and the wall thickness of the self-expanding stent ( Figure 4 δ) is greater than the width of the connecting rod 16 at the non-proximal edge of the grid 12 ( Figure 4 w1) is 0.01-0.04mm larger.

[0014] The connection relationship between the self-expanding stent 1, the delivery guidewire 2 and the introduction sheath 3 of the present invention can refer to the prior art, for example, the assembled delivery guidewire and stent are pressed and gripped into the introduction sheath.

[0015] According to some specific embodiments of the present invention, the self-expanding stent and the delivery guide wire are connected to each other, the developing ring or the developing spring is first passed through the delivery guide wire, and then the proximal end of the developing ring or the developing spring is fixed to the delivery guide wire by welding, bonding, pressing and gripping, and finally the distal end of the developing ring or the developing spring is fixed together with the expansion stent and the distal end of the delivery guide wire by welding, bonding, pressing and gripping.

[0016] The materials used to make the developing ring and the developing spring are visible under X-rays, which allows doctors to clearly observe the position of the stent in the blood vessel during surgery.

[0017] The wall thickness of the entire stent of the present invention is greater than the rod width, so that the stent has better size recovery performance and provides greater radial support force, making it easier for the stent to embed into the thrombus.

[0018] The sparse grid in the middle of the stent of the present invention is the main part of the stent, and its grid is large, which is convenient for grabbing and embedding most of the thrombi; the dense grid at the distal end is mainly used to pick up thrombi with smaller volume. When the thrombus remover is withdrawn, the thrombus and the stent will move relative to each other, causing the thrombus to fall off at the distal end of the stent. The proximal end uses a dense grid and increases the width of the open ramp mouth rod at the same time, which mainly provides better force transmission performance during the delivery of the thrombus remover, so that the thrombus remover stent can smoothly reach the lesion site; the dense grid at the distal end can effectively solve the problem of thrombi slipping at the distal end of the stent and prevent secondary embolism.

[0019] According to some specific embodiments of the present invention, the area of ​​a single grid of the middle section grid is 7-13 mm 2 .

[0020] According to some specific embodiments of the present invention, the area of ​​a single grid of the middle segment grid is 10 mm 2 .

[0021] According to some specific embodiments of the present invention, the wall thickness δ of the self-expanding stent is 0.02 mm greater than the width w1 of the connecting rods 16 forming the grid 12 .

[0022] According to some specific embodiments of the present invention, the width w1 of the connecting rods 16 forming the grid 12 is 0.05-0.09 mm.

[0023] According to some specific embodiments of the present invention, the wall thickness δ of the self-expanding stent is 0.06-0.11 mm.

[0024] According to some specific embodiments of the present invention, the wall thickness δ of the self-expanding stent is 0.07-0.10 mm.

[0025] According to some specific embodiments of the present invention, a smooth edge connecting rod 161 is provided at the proximal edge of the self-expanding stent 1, and the distal edge is open.

[0026] The distal end of the self-expanding stent is open in design, and the distal end of the stent is softer, which is conducive to the stent turning without hindering blood circulation.

[0027] It is understood that the distal edge is open, which means that the distal edge is directly formed by the connecting rods 16 of the grid 12 without specially provided edge connecting rods.

[0028] It can also be understood that the smooth edge connecting rod 161 provided at the proximal edge of the self-expanding stent 1 is roughly smooth, rather than absolutely smooth, and the smoothness is relative to the substantially serrated distal edge directly formed by the connecting rod 16 .

[0029] According to some specific embodiments of the present invention, the middle section 14 accounts for 1 / 2-2 / 3 of the total length of the self-expanding stent 1 .

[0030] According to some specific embodiments of the present invention, the length ratio of the distal end 13 to the proximal end 15 of the self-expanding stent 1 is 1:1-1:2.

[0031] According to some specific embodiments of the present invention, the length ratio of the distal end 13 to the proximal end 15 of the self-expanding stent 1 is 1:1.

[0032] According to some specific embodiments of the present invention, the length of the self-expanding stent 1 (eg Figure 2 l) shown is 28.0-42.0mm.

[0033] According to some specific embodiments of the present invention, the single grid area ratio of the middle section 14 to the proximal end 15 of the self-expanding stent 1 is 2:0.5-1.5; the single grid area ratio of the proximal end 15 to the distal end 13 is 1:1-1.9:1.

[0034] According to some specific embodiments of the present invention, the ratio of the single grid area between the middle section 14 and the proximal end 15 of the self-expanding stent 1 is 2:1.

[0035] In the above-mentioned thrombus remover, preferably, the grid area in the proximal end of the self-expanding stent is the same; the grid area in the distal end is the same; the sparse grid area in the middle is the same and is an integer relationship of the small grid area at the distal end (preferably a multiple of 2).

[0036] It can be understood that since the edge connecting rod 161 is provided at the proximal edge, the edge connecting rod 161 becomes a partial connecting rod constituting the grid at the proximal edge. It can also be understood that the size of the grid at the proximal edge can be appropriately adjusted as needed. For example, when the area of ​​the new grid formed by the edge connecting rod 161 and the grid at the edge is smaller than 1 / 2 of the area of ​​the proximal grid, the bracket between the new grid and the original grid at the edge is removed to form a grid with a slightly larger area.

[0037] According to some specific embodiments of the present invention, the grid of the present invention is arranged in a spiral shape.

[0038] According to some specific embodiments of the present invention, the width of the edge connecting rod 161 (eg Figure 5 The illustrated width w2) is 0.01-0.03 mm greater than the width w1 of the link 16 at the non-proximal edge of the self-expanding stent.

[0039] According to some specific embodiments of the present invention, the width w2 of the edge link 161 is 0.025-0.03 mm greater than the width w1 of the link 16 at the non-proximal edge of the self-expanding stent.

[0040] According to some specific embodiments of the present invention, the width w2 of the edge connecting rod 161 is 0.06-0.12.

[0041] According to some specific embodiments of the present invention, the width w2 of the edge connecting rod 161 is 0.07-0.11.

[0042] According to some specific embodiments of the present invention, the edge connecting rod 161 forms a slope 162 relative to the delivery guide wire 2.

[0043] According to some specific embodiments of the present invention, the angle α between the delivery guide wire 2 and the slope 162 is 135°-150°.

[0044] It can be understood that the angle α between the delivery guide wire 2 and the slope 162 refers to the angle between the vertical projection of the delivery guide wire on the slope and the delivery guide wire.

[0045] According to some specific embodiments of the present invention, the end 163 of the slope 162 close to the user is formed by a connecting grid 164, and the connecting grid is composed of two connecting rods 165 and two supporting rods 166. The two connecting rods are part of the edge rods, and the delivery guide wire 2 is connected to the intersection of the two connecting rods 165.

[0046] According to some specific embodiments of the present invention, the width of the support link 166 (eg Figure 5 The width w3) shown is 0.01-0.02 mm larger than the width w1 of the connecting rod 16 .

[0047] According to some specific embodiments of the present invention, the width w3 of the supporting link 166 is 0.06-0.11.

[0048] According to some specific embodiments of the present invention, the delivery guide wire 2 is made of metal.

[0049] According to some specific embodiments of the present invention, the delivery guide wire 2 is made of an alloy of nickel and / or titanium.

[0050] According to some specific embodiments of the present invention, the delivery guide wire 2 is made of nickel alloy.

[0051] According to some specific embodiments of the present invention, the delivery guide wire 2 is made of titanium alloy.

[0052] According to some specific embodiments of the present invention, the delivery guide wire 2 is made of an alloy of nickel and titanium.

[0053] According to some specific embodiments of the present invention, the introduction sheath 3 is made of high molecular polymer.

[0054] According to some specific embodiments of the present invention, the introduction sheath 3 is made of polytetrafluoroethylene.

[0055] According to some specific embodiments of the present invention, the self-expanding stent 1 is made of memory alloy.

[0056] According to some specific embodiments of the present invention, the self-expanding stent 1 is made of nickel-titanium alloy.

[0057] According to some specific embodiments of the present invention, the self-expanding stent 1 is made of memory alloy by laser cutting.

[0058] According to some specific embodiments of the present invention, the self-expanding stent 1 is made of nickel-titanium alloy by laser cutting.

[0059] During delivery, the stent can be pressed and grasped into the introduction sheath or microcatheter under the action of external force; when the restraining external force of the introduction sheath or microcatheter disappears, the stent can self-expand into a complete tubular structure.

[0060] According to some specific embodiments of the present invention, the delivery guide wire 2 includes, in sequence from the end close to the user, a first sizing section 21, a first diameter-reducing section 22, a second diameter-reducing section 28, a second sizing section 23 and a third diameter-reducing section 24, a developing wire 25 is arranged on the outer surfaces of the third diameter-reducing section and the second sizing section, and a polymer heat-shrinkable tube 26 is coated on the outer surfaces of the developing wire 25 and the second diameter-reducing section 28.

[0061] The first fixed diameter section 21 is connected to one end of the first reducing diameter section 22, the other end of the first reducing diameter section 22 is connected to one end of the second reducing diameter section 28, the other end of the second reducing diameter section is connected to one end of the third reducing diameter section, the other end of the third reducing diameter section is connected to one end of the second fixed diameter section, and the other end of the second fixed diameter section is connected to the third reducing diameter section.

[0062] According to some specific embodiments of the present invention, the developing wire is in the shape of a spring or a developing ring.

[0063] According to some specific embodiments of the present invention, the length of the first sizing section 21 is 0.6-0.7 times the total length of the delivery guidewire, the lengths of the first reducing section 22 and the second reducing section 28 are each independently 0.1-0.2 times the total length of the delivery guidewire, the length of the second sizing section 23 is 0.05-0.1 times the total length of the delivery guidewire, and the length of the third reducing section 24 is 0.03 times the total length of the delivery guidewire.

[0064] According to some specific embodiments of the present invention, the first diameter-changing section 22 changes the diameter from the diameter of the first sizing section 21 to 0.5-0.6 times of the original diameter, the second diameter-changing section 28 gradually changes the diameter to 0.4-0.48 times of the first sizing section 21, and the third diameter-changing section 24 changes the diameter from the diameter of the second sizing section 23 to 0.2-0.3 times of the diameter of the first sizing section.

[0065] According to some specific embodiments of the present invention, the first diameter-changing section 22 changes the diameter of the first diameter-fixing section 21 to 0.56 times of the original diameter.

[0066] According to some specific embodiments of the present invention, the second diameter-changing section 28 gradually changes its diameter to 0.42 times that of the first diameter-fixed section 21 .

[0067] According to some specific embodiments of the present invention, the third diameter-changing section 24 changes the diameter from the second diameter-fixed section to 0.28 times of the first diameter-fixed section 21 .

[0068] It can be understood that the original diameter mentioned in the present invention refers to the diameter of each diameter-changing section at the starting position, that is, the diameter of the connection between the diameter-changing section and the previous section (the previous constant diameter section or the previous diameter-changing section).

[0069] According to some specific embodiments of the present invention, the first diameter-changing section 22 changes the diameter from the diameter of the first diameter-fixing section 21 to 0.56 times the original diameter, and the second diameter-changing section 28 changes the diameter from the original diameter to 0.42 times the diameter of the first diameter-fixing section 21 .

[0070] The shape and structure of the delivery guide wire 2 of the present invention can refer to the prior art, and according to some specific embodiments of the present invention, the proximal end of the delivery guide wire 2 is of equal diameter design, and the equal diameter length is 0.6-0.7 times the total length of the delivery guide wire, and the distal end is of gradually tapering design, and the distal end length is 0.3-0.4 times the total length of the delivery guide wire. The distal end mainly has three diameter-changing designs, the first one is connected to the proximal end, and the diameter size gradually changes to 0.56 times the proximal end diameter, and the gradual length is 0.1 times the total length of the delivery guide wire, followed by the second diameter-changing section, and the diameter size gradually changes to 0.42 times the proximal end diameter, and the gradual length is 0.1 times the total length of the delivery guide wire. The third diameter change is immediately followed by the second sizing section, and the diameter size gradually changes to 0.28 times the diameter of the first sizing section, and the gradual length is 0.03 times the total length of the delivery guide wire.

[0071] The distal end of the delivery guide wire is designed with a variable diameter, which is smaller in size and more flexible, and plays a good guiding role during surgery; the proximal end is designed with a constant diameter, which is larger in size and more rigid, and can provide better transmission performance, making it easier for the entire thrombectomy device to reach the site of vascular lesions.

[0072] In the above-mentioned thrombus remover, preferably, a developing wire runs through the entire length direction of the self-expanding stent, so that the stent can clearly show its opened state under X-ray.

[0073] The connection method of the self-expanding stent and the delivery guide wire can refer to the existing conventional connection methods, such as bonding or welding the two.

[0074] According to some specific embodiments of the present invention, a connecting rod 167 is provided at the intersection of the two connecting rods 165 of the self-expanding stent 1 , and the connecting rod 167 is inserted into the gap between the third diameter-reducing section 24 of the delivery guide wire 2 and the developing wire 25 .

[0075] According to some specific embodiments of the present invention, the connecting rod 167 and the third diameter-reducing section 24 may also be connected to each other by bonding or welding.

[0076] According to some specific embodiments of the present invention, a connecting sleeve 4 may be further provided at the periphery of the connection between the connecting rod 167 and the delivery guide wire, and the connecting sleeve covers a portion of the connecting rod 167 and the distal end of the delivery guide wire.

[0077] According to some specific embodiments of the present invention, the connecting sleeve 4 is a developing tube or a developing spring.

[0078] According to some specific embodiments of the present invention, the sleeve 4, the connecting rod 167, and the distal end of the delivery guide wire may be further fixed by bonding or welding.

[0079] According to some specific embodiments of the present invention, the inner diameters of the two ends of the connecting sleeve respectively match the size of the connecting rod 167 and the outer diameter of the distal end of the delivery guide wire 2, and the connecting rod 167 and the distal end of the delivery guide wire 2 are inserted into the connecting sleeve 4.

[0080] In summary, the present invention provides a thrombus remover. The thrombus remover of the present invention has the following advantages:

[0081] Compared with the existing mechanical thrombectomy technology, the design structure adopted by the present invention has the following advantages: the wall thickness of the thrombectomy stent is greater than the rod width, different parts have grids of different sizes, and these grids are arranged in a spiral in the circumferential direction of the stent, the large grid in the middle captures or embeds most of the thrombus, and the distal ends are in the same vertical plane, reducing the unnecessary length of the stent, while the small grid at the distal end is used to capture thrombi with smaller volumes, and can also prevent secondary embolism caused by thrombi falling off at the distal end of the stent. Increasing the width of the proximal edge link 161 and the support link 166 can provide better transmission performance for the thrombectomy device. The previous design was that the width of the proximal edge link 161 and the support link 166 and the width of the link 16 of the grid 12 were the same, and the push resistance was large during the test. Later, the width of the edge link 161 was increased by 0.025-0.03mm, and the width of the support link 166 was increased by 0.01-0.02mm. In the test, the push resistance changed from relatively smooth to very smooth. Good transfer performance can make the thrombectomy stent reach the lesion site smoothly and achieve accurate positioning; the full-process development of the stent provides great convenience for the operation, and the operator can clearly observe the relative position of the stent and the thrombus, and the expansion state of the stent, ensuring that the thrombectomy process is more accurate and reliable; the thrombectomy device of the present invention has a simple structure, a small outer diameter after the product is squeezed and gripped, and has high flexibility, so it can reach the tortuous lesion blood vessel site more conveniently; the product is easy to operate, which not only reduces the operator's workload, but also buys precious time for the patient's vascular recanalization. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] Figure 1 This is the overall schematic diagram of the thrombectomy device;

[0083] Figure 2 A schematic diagram of a self-expanding stent of the thrombus retriever;

[0084] Figure 3 This is a schematic diagram of the plane deployment of the self-expanding stent of the thrombus retriever;

[0085] Figure 4 A partial schematic diagram of a mesh of a self-expanding stent;

[0086] Figure 5 A schematic diagram of an edge link at the proximal edge of a self-expanding stent;

[0087] Figure 6 Schematic diagram of the guide wire for thrombectomy;

[0088] Figure 7 Schematic diagram of the thrombectomy device introduction sheath;

[0089] Figure 8 A schematic diagram of the connection relationship between the self-expanding stent of the thrombus remover and the delivery guide wire;

[0090] Figure 9aA schematic diagram of a developing spring for connecting the thrombus remover stent to the delivery guide wire;

[0091] Figure 9b This is a schematic diagram of a developing ring used to connect the thrombus remover stent to the delivery guide wire;

[0092] Fig.10 This is a test diagram of the pushing resistance of the thrombectomy device No. Q201704214020002 into the sheath;

[0093] Fig.11 This is the push resistance test diagram of the microcatheter No. Q201704214020002;

[0094] Fig.12 This is the push resistance test chart of the introduction sheath No. Q201704214020005;

[0095] Fig.13 This is the push resistance test diagram of the microcatheter No. Q201704214020005;

[0096] Fig.14 This is the push resistance test chart of the introduction sheath No. Q201705114020001;

[0097] Fig.15 This is the push resistance test diagram of the microcatheter No. Q201705114020001;

[0098] Fig.16 This is the push resistance test chart of the sheath No. Q201707044020002;

[0099] Fig.17 This is the push resistance test diagram of the microcatheter No. Q201707044020002;

[0100] Fig.18 The push resistance test chart of the sheath is No. Q201707044020004;

[0101] Fig.19 This is the microcatheter push resistance test diagram numbered Q201707044020004. DETAILED DESCRIPTION

[0102] The implementation process of the present invention and the beneficial effects produced are described in detail below through specific embodiments, which is intended to help readers better understand the essence and characteristics of the present invention, and is not intended to limit the scope of implementation of the present invention.

[0103] Example 1

[0104] For ease of description, the following description uses the terms “proximal end” and “distal end”, wherein the “proximal end” refers to an end close to an operator and the distal end refers to an end far from an operator.

[0105] Figure 1 The thrombus removal device comprises a self-expanding stent 1, a delivery guide wire 2 and an introduction sheath 3, wherein the delivery guide wire and the stent are connected together by welding, bonding, pressing and holding through a developing ring or a developing spring. Figure 1 The stent is shown in the state after being released and deployed; the assembled thrombectomy product is the stent and the delivery guide wire pressed and grasped in the introduction sheath.

[0106] Figure 2 and Figure 3 The stent grid has a sparse grid 12 in the middle section 14 of the stent that is significantly larger than the grids at the proximal end 15 and the grids at the distal end 13. The area of ​​the grid in the middle section is twice that of the grids at the proximal and distal ends. The length of the middle section of the sparse grid accounts for half of the total length of the stent. The length ratio between the proximal and distal ends is 1:1, and the total length of the stent is 35 mm. The distal grid is arranged in at least one cycle in the circumferential direction. At least one proximal grid is located at the bifurcation of the nearest ramp of the stent. In this way, the large middle grid can be used as the main thrombus removal part to capture or embed most of the thrombi. The distal grid is used to capture smaller thrombi, thereby preventing the thrombi captured by the grid from sliding off the distal end of the stent and causing secondary embolism. When the thrombus removal device is delivered, the proximal grid can transfer the operator's pushing force from the delivery guide wire to the stent, so that the thrombus removal stent can reach the lesion site smoothly.

[0107] exist Figure 2 and Figure 3 The skeleton of the stent is penetrated by a developing ring from the proximal end to the distal end. This ring is made of a material that is opaque to X-rays, which is helpful in determining the relative position of the stent and the thrombus, facilitating the observation of the opening shape of the stent during surgery, and ensuring the degree of integration of the stent and the thrombus.

[0108] Figure 3 This is a schematic diagram of the winding position of the bracket development ring. The entire bracket contains 9 development points, and the 9 development points can construct the outer diameter and limited length of the bracket.

[0109] Figure 4 This is a partial enlarged view of the bracket's mesh; Figure 5 This is an enlarged view of the edge connecting rod 161 at the proximal edge (this figure only shows the edge connecting rod and the corresponding connecting rod of the connecting grid, and other grids and corresponding connecting rods are omitted for clarity). Among them, a section of the edge connecting rod 161 close to the delivery guide wire is used as a connecting rod (i.e., connecting rod 165) to form the connecting grid 164. The width w3 of the supporting connecting rod 166 is 0.02 mm larger than the width w1 of the connecting rod 16.

[0110] The wall thickness δ of the self-expanding stent is 0.02 mm greater than the width w1 of the connecting rods 16 at the non-proximal edge of the grid 12, which is 0.08. The width w2 of the edge connecting rods 161 is 0.028 mm greater than the width w1 of the connecting rods 16 at the non-proximal edge of the self-expanding stent.

[0111] The edge connecting rod 161 forms a slope 162 relative to the conveying guide wire 2, and the included angle α between the conveying guide wire 2 and the slope 162 is 140°.

[0112] Figure 6 The schematic diagram of the thrombus removal device delivery guide wire 2 is mainly composed of a core wire, an X-ray-opaque development spring 25, and a polymer heat shrink tube 26. The core wire is made of a soft, variable-diameter metal wire material with a certain rigidity, which not only ensures the support and transmission performance during the delivery of the thrombus removal device, but also provides a certain degree of flexibility, which is conducive to the stent passing through tortuous blood vessels and lesions smoothly and achieving accurate positioning.

[0113] The delivery guide wire 2 is sequentially divided into a first sizing section 21, a first diameter-reducing section 22, a second diameter-reducing section 28, a second sizing section 23 and a third diameter-reducing section 24 from the end close to the user, and a developing spring 25 is arranged on the outer surface of the second sizing section and the third diameter-reducing section, and a high molecular polymer heat shrink tube 26 is coated on the outer surface of the developing spring 25 and the second diameter-reducing section 28. The length of the first sizing section 21 is 0.57 times the total length of the delivery guide wire, the length of the first diameter-reducing section 22 and the second diameter-reducing section 28 are respectively 0.15 times the total length of the delivery guide wire, the length of the second sizing section is 0.1 times the total length of the delivery guide wire, and the length of the third diameter-reducing section is 0.03 times the total length of the delivery guide wire. The first diameter-changing section 22 changes the diameter from the diameter of the first diameter-fixed section 21 to 0.56 times the original diameter, the second diameter-changing section 28 changes the diameter to 0.42 times the diameter of the first diameter-fixed section, and the third diameter-changing section 24 changes the diameter from the diameter of the second diameter-fixed section 23 to 0.28 times the diameter of the first diameter-fixed section.

[0114] Figure 7 The introduction sheath 3 is an extruded tube made of a high molecular polymer material with a small friction coefficient. It can not only protect the stent during packaging and ensure its stability, but also facilitate the introduction of the thrombectomy device into the microcatheter during surgery, thereby achieving the purpose of rapid delivery.

[0115] Figure 9a and Figure 9b There are two devices with different structures that can be used to connect the stent and the delivery guide wire. Figure 9a For the developing spring, Figure 9b The developing ring is connected by placing the connecting rod 167 of the self-expanding stent and the third diameter-changing section 24 of the conveying guide wire in the developing spring 9a or the developing ring 9b (such as Figure 8As shown), the two are then connected by welding, bonding or pressing and gripping. The developing spring 9a and the developing ring 9b are both made of X-ray-proof materials, which is conducive to the accurate positioning of the support and improves the success rate of the operation.

[0116] Test Case

[0117] Table 1. Dimensions of the bracket to be tested

[0118]

[0119] The rod widths of the products numbered Q201704214020002 and Q201704214020005 in Table 1 above are substantially the same; the rod width parameters of the products with other numbers all meet the requirements of the present invention.

[0120] System flexibility, push and retracement performance testing

[0121] Test method: Test according to the “Test method for pushing, compliance and retraction of thrombectomy device”.

[0122] Acceptance criteria: The stent should be able to be pushed along the lumen of the introduction sheath and microcatheter in the simulated blood vessel model, and should be able to reach the designated marked position without bending or wrinkling, and the process pushing force should be ≤150gf. Figure 10-19 .

[0123] The test results are shown in Table 2:

[0124] Table 2. Thrombectomy performance test

[0125]

[0126]

[0127] As shown in Table 2, all sizes of thrombus removers can reach the target position along the introduction sheath or microcatheter, and the flexibility is qualified; the thrombus remover can be withdrawn from the introduction sheath or microcatheter normally, and the retraction performance is qualified. However, the flexibility, pushing and retraction performance of the products numbered Q201704214020002 and Q201704214020005 are worse than those of the product of the present invention. The thrombus remover of the present invention can have better operating performance.

Claims

1. A thrombus remover, comprising a cylindrical self-expanding stent (1) with openings at both ends, a delivery guide wire (2) and an introduction sheath (3), wherein: The wall (11) of the self-expanding stent is composed of a hollow grid (12). The self-expanding stent (1) is divided into three parts along the length direction from the connection with the delivery guide wire (2): a proximal end (15), a middle section (14) and a distal end (13); the single grid area of ​​the grid of the middle section (14) is larger than the single grid area of ​​the distal end (13) and the proximal end (15), and the single grid area of ​​the grid of the middle section is 7-13 mm2; a smooth edge connecting rod (161) is arranged at the proximal edge of the self-expanding stent (1), and the wall thickness of the self-expanding stent is 0.01-0.04 mm greater than the width of the connecting rod (16) at the non-proximal edge forming the grid (12); the width of the connecting rod (16) forming the grid (12) is 0.05-0.09 mm; the edge connecting rod (161) is 0.01-0.04 mm thick; the wall thickness of the self-expanding stent is 0.01-0.04 mm thicker ... 1) is 0.01-0.03mm wider than the width of the connecting rod (16) at the non-proximal edge of the self-expanding stent; the edge connecting rod (161) forms a slope (162) relative to the delivery guide wire (2); the slope (162) is formed by a connecting grid (164) at the end (163) close to the user, and the connecting grid is composed of two connecting rods (165) and two supporting connecting rods (166), the two connecting rods are part of the edge connecting rod, and the delivery guide wire (2) is connected to the intersection of the two connecting rods (165); the width of the supporting connecting rod (166) is 0.01-0.02mm wider than the width of the connecting rod (16), and the length ratio of the distal end (13) and the proximal end (15) of the self-expanding stent (1) is 1:1-1:

2.

2. The thrombus remover according to claim 1, wherein: The single grid area of ​​the middle section grid is 10mm2.

3. The thrombus remover according to claim 1, wherein: The wall thickness of the self-expanding stent is 0.02 mm greater than the width of the connecting rods (16) at the non-proximal edge forming the grid (12).

4. The thrombus remover according to claim 1, wherein: The middle section (14) accounts for 1 / 2-2 / 3 of the total length of the self-expanding stent (1).

5. The thrombus remover according to claim 1, wherein: The length ratio between the distal end (13) and the proximal end (15) of the self-expanding stent (1) is 1:

1.

6. The thrombus remover according to claim 1, wherein: The length of the self-expanding stent (1) is 28.0-42.0 mm.

7. The thrombus remover according to claim 1, wherein: The single grid area ratio between the middle section (14) and the proximal end (15) of the self-expanding stent (1) is 2:(0.5-1.5); the single grid area ratio between the proximal end (15) and the distal end (13) is 1:1-1.9:

1.

8. The thrombus remover according to claim 7, wherein: The ratio of the single grid area between the middle section (14) and the proximal end (15) of the self-expanding stent (1) is 2:

1.

9. The thrombus remover according to claim 1, wherein: The included angle α between the conveying guide wire (2) and the slope surface (162) is 135°-150°.

10. The thrombus remover according to claim 1, wherein: The delivery guide wire (2) is made of metal.

11. The thrombus remover according to claim 10, wherein: The delivery guide wire (2) is made of an alloy of nickel and / or titanium.

12. The thrombus remover according to claim 1, wherein: The introduction sheath tube (3) is made of high molecular polymer.

13. The thrombus remover according to claim 12, wherein: The high molecular polymer is polytetrafluoroethylene.

14. The thrombus remover according to claim 1, wherein: The self-expanding stent (1) is made of memory alloy.

15. The thrombus remover according to claim 14, wherein: The memory alloy is nickel-titanium alloy.

16. The thrombus remover according to claim 14, wherein: The self-expanding stent (1) is made of memory alloy by laser cutting.

17. The thrombus remover according to claim 1, wherein: The delivery guide wire (2) comprises, in order from the end close to the user, a first sizing section (21), a first diameter-reducing section (22), a second diameter-reducing section (28), a second sizing section (23) and a third diameter-reducing section (24); a developing wire (25) is arranged on the outer surfaces of the second sizing section and the third diameter-reducing section; and a high molecular polymer heat shrink tube (26) is coated on the outer surfaces of the developing wire (25) and the second diameter-reducing section (28).

18. The thrombus remover according to claim 17, wherein: The developing wire is in the shape of a spring or a developing ring.

19. The thrombus remover according to claim 17, wherein: The length of the first sizing section (21) is 0.6-0.7 times the total length of the delivery guidewire, the length of the first reducing section (22) and the second reducing section (28) are each independently 0.1-0.2 times the total length of the delivery guidewire, the length of the second sizing section is 0.05-0.1 times the total length of the delivery guidewire, and the length of the third reducing section is 0.03 times the total length of the delivery guidewire.

20. The thrombus remover according to claim 19, wherein: The first diameter-changing section (22) changes the diameter from the diameter of the first diameter-fixing section (21) to 0.5-0.6 times the original diameter, the second diameter-changing section (28) changes the diameter from the diameter of the first diameter-fixing section (21) to 0.4-0.48 times the original diameter, and the third diameter-changing section (24) changes the diameter from the diameter of the second diameter-fixing section (23) to 0.2-0.3 times the diameter of the first diameter-fixing section.

21. The thrombus remover according to claim 20, wherein: The first diameter-changing section (22) changes the diameter from the diameter of the first diameter-fixing section (21) to 0.56 times the original diameter; the second diameter-changing section (28) changes the diameter from the diameter of the first diameter-fixing section (21) to 0.42 times the original diameter; and the third diameter-changing section (24) changes the diameter from the diameter of the second diameter-fixing section (23) to 0.28 times the diameter of the first diameter-fixing section.

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