CN109938801A - A thrombectomy device - Google Patents

Abstract

The present invention provides a kind of thrombus to take bolt device.It is described that bolt device is taken to include the tubular self-expanding stent (1) of both ends open, delivery guidewire (2) and import sheath (3), the wall (11) of the self-expanding stent is that the grid (12) of hollow out forms, and the self-expanding stent (1) is divided into three parts: proximal end (15), interlude (14) and distal end (13) along its length from delivery guidewire (2) junction；The single grid area of interlude (14) grid is greater than the single grid area of distal end (13) and proximal end (15), smooth edge connecting rod (161) is set at self-expanding stent (1) proximal edge, and the wall ratio of the self-expanding stent forms the big 0.01-0.04mm of width of the connecting rod (16) at the non-proximal edge of grid (12).

Description

A thrombectomy device

technical field

The present invention relates to medical equipment, in particular, the present invention relates to a thrombectomy device.

Background technique

Stroke is one of the main causes of human death and disability, and acute ischemic stroke (AIS) accounts for about 80% of all strokes. Research shows that there are about 7.5 million stroke people in China, and 2.5 million new strokes occur every year, of which about 1.6 million die, which seriously endangers human life. The key to the treatment of AIS is to open the blocked blood vessels as soon as possible and save the ischemic penumbra. Intravenous recombinant tissue plasminogen activator (rt-PA) thrombolysis has been proven to be an effective treatment for AIS, and the earlier the treatment, the greater the benefit. However, it is limited by the strict time window and 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 degree of benefit is limited. In order to solve the drawbacks of intravenous thrombolysis, domestic and foreign scholars have carried out clinical research on endovascular treatment methods. The results of the study show that, among endovascular treatment methods, intra-arterial thrombolysis can not only determine the location of the actual thrombus 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 the operation, and there is a risk of intervention-related complications, which increases the rate of symptomatic intracranial hemorrhage. Therefore, in clinical treatment, the superiority of arterial thrombolysis over intravenous thrombolysis cannot be determined.

In view of the drawbacks of clinical treatment, the research results of endovascular treatment based on mechanical thrombectomy have been recognized by everyone. The results of a number of foreign randomized controlled studies have confirmed that in the occlusive lesions of large intracranial vessels, the early implementation of stent-based thrombectomy Endovascular interventional therapy represented by thrombotic devices can significantly improve the prognosis of patients and improve the success rate of treatment, especially the design of thrombectomy stents, which is the key to successful clinical treatment.

At present, the research of thrombectomy stent in my country has also achieved staged results.

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

The design of the helical structure is also the same, and the blood vessel thrombectomy device in the invention patent disclosed in CN10662533A is easier to remove the thrombus. The thrombus remover is a mesh or cage-like structure composed of multiple units, and the sides have longitudinal gaps, and the longitudinal gaps extend spirally along the outer surface of the mesh-like or cage-like structure. However, thrombectomy may occur during thrombectomy.

In order to avoid the problem of thrombus removal and falling off, CN105476689A discloses a device for removing a thrombus. The device includes a front thrombus removal support and a rear protection support, and the two remove the thrombus in succession to prevent the thrombus from falling off. However, the patented product includes a bolus removal bracket and a protective bracket, which greatly reduces the effective length of the bolus retrieval bracket, increases the overall length of the bracket, and seriously affects the flexibility of the product. Also affecting the flexibility of the product is an intracranial blood vessel thrombectomy device and a thrombectomy device disclosed in patent CN104068909A. Although the product has a concave or convex structure, which can fix the thrombus in the process of capturing and recovering the thrombus, this structure will seriously affect the outer diameter of the product after pressing and the overall flexibility of the product, making it very It is difficult to pass through the tortuous blood vessels, and the convex structure may cause the blood vessels to spasm, causing damage to the blood vessels.

CN103284775B discloses an intracranial thrombus removal device, the distal end of the thrombectomy stent is controllable, the closure can prevent the thrombus from falling off and blocking the distal blood vessel, and it can also be opened as a blood flow remodeling device. However, the structure and operation of this product are complex, which affects the recanalization time of blood vessels.

CN105997314A discloses a composite function thrombus elimination system, which includes a stent in the form of a mesh tube, which 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 the thrombus can be extracted multiple times with high efficiency; the covered segment of the stent can also temporarily block blood flow to prevent small thrombi from blocking the distal blood vessels. However, the patented stent adopts a braiding method, which results in a small radial force of the stent. Grabbing the thrombus may easily cause the thrombus to rupture or fall off. The fallen thrombus needs to be repeatedly grasped, and the ruptured smaller thrombus may cause the blood vessel to be farther away. end blocked. At the same time, the covered segment of the stent will increase the outer diameter of the stent after compression, which will affect the flexibility of the entire system and make it more difficult to pass through the more tortuous blood vessels.

Therefore, although there are many products of thrombectomy stents in China, their product structure is complicated, the operation is cumbersome, and the flexibility is poor. In clinical application, it is often difficult to remove the thrombus or the thrombus falls off, which cannot meet the clinical application. The thrombectomy stent device is a hot and difficult point in current clinical research.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a thrombectomy device. The thrombectomy device can effectively improve the thrombus capturing efficiency, and solve the problem that the vascular wall plaque and broken thrombus in the prior art are easy to fall off and cause re-embolization of the distal blood vessel; at the same time, the outer diameter is small and flexible after pressing It can quickly pass through the curved blood vessels to reach the distant and thinner blood vessels to achieve the purpose of treatment.

For ease of description, the following description uses the terms "proximal end" and "distal end", where "proximal end" refers to the end close to the operator and distal end refers to the end away from the operator.

In order to achieve the above-mentioned purpose, the present invention provides a thrombectomy thrombectomy device, which comprises a cylindrical self-expanding stent 1 with openings at both ends, a delivery guide wire 2 and an introduction sheath 3, wherein the self-expanding stent The wall 11 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: the proximal end 15, the middle section 14 and the distal end 13; the middle section 14 mesh The single grid area of the grid is larger than the single grid area of the distal end 13 and the proximal end 15, and a smooth edge connecting rod 161 is provided at the proximal end edge of the self-expanding stent 1. The wall thickness of the self-expanding stent (δ in FIG. 4 ) 0.01-0.04 mm greater than the width of the link 16 at the non-proximal edge forming the grid 12 (w1 in FIG. 4 ).

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

According to some specific embodiments of the present invention, wherein, the self-expanding stent and the delivery guide wire are connected to each other, firstly, a developing ring or a developing spring is threaded on the delivery guide wire, and then welding, bonding, crimping, etc. are used to connect the The proximal end of the developing ring or the developing spring is fixed with the delivery guide wire, and finally the distal end of the developing ring or the developing spring and the distal end of the expanding stent and the delivery guide wire are fixed together by welding, bonding, and pressing.

The materials made of the developing ring and the developing spring can be seen under X-rays, so that the doctor can clearly observe the position of the stent in the blood vessel during the operation.

The wall thickness of the whole stent of the present invention is larger than the rod width, so that the stent has better dimensional recovery performance, and at the same time provides a larger radial support force, which is convenient for the stent to embed the thrombus.

The sparse grid in the middle of the stent of the present invention is the main part of the stent, and the grid is large, which is convenient for grasping and embedding most thrombus; When the device is inserted, the thrombus and the stent will move relative to each other, causing the thrombus to fall off at the distal end of the stent. A dense mesh is used at the proximal end and the width of the open chamfered mouth is increased. The main function is to provide better force transmission performance during the delivery of the thrombectomy device, so that the thrombectomy stent can reach the lesion smoothly; the dense mesh at the distal end is used. The grid can effectively solve the problem of thrombus slipping at the distal end of the stent and prevent secondary embolism.

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

According to some specific embodiments of the present invention, the single grid area of the grid of the middle section is 10 mm ² .

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 .

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.

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

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

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

The distal end of the self-expanding stent is of an open design, and the distal end of the stent will be more flexible, which facilitates the stent to bend, and does not hinder the circulation of blood.

It can be understood that the said distal edge is open, which means that the distal edge is directly formed by the connecting rods 16 of the grid 12, and no edge connecting rods are specially provided.

It can also be understood that the smooth edge link 161 disposed at the proximal edge of the self-expanding stent 1 is roughly smooth, not absolutely smooth, and the smoothness is relatively directly formed by the link 16 The generally serrated distal edge.

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

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

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

According to some specific embodiments of the present invention, the length of the self-expanding stent 1 (1 as shown in FIG. 2 ) is 28.0-42.0 mm.

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

According to some specific embodiments of the present invention, the area ratio of a single mesh of the middle section 14 to the proximal end 15 of the self-expanding stent 1 is 2:1.

In the above thrombectomy device, preferably, the mesh area in the proximal end of the self-expanding stent is the same; the mesh area in the distal end is the same; the sparse mesh area in the middle is the same and is an integer of the small mesh area at the distal end relationship (preferably a multiple of 2).

It can be understood that, because the edge link 161 is provided at the proximal edge, the edge link 161 becomes a part of the link that constitutes the grid at the proximal edge. It can also be understood that the proximal link can be adjusted as required The size of the mesh at the edge is appropriately adjusted. For example, when the area of the new mesh formed by the edge link 161 and the mesh at the edge is less than 1/2 of the mesh area at the near end, the new mesh and the original edge are removed. brackets between the grids to form a slightly larger grid.

According to some specific embodiments of the present invention, the grids of the present invention are arranged in a spiral shape.

According to some embodiments of the present invention, the width of the edge link 161 (w2 as shown in FIG. 5 ) 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.

According to some 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.

According to some specific embodiments of the present invention, the width w2 of the edge link 161 is 0.06-0.12.

According to some specific embodiments of the present invention, the width w2 of the edge link 161 is 0.07-0.11.

According to some specific embodiments of the present invention, the edge link 161 forms a slope 162 relative to the delivery guide wire 2 .

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

It can be understood that the included angle α between the conveying guide wire 2 and the slope surface 162 refers to the vertical projection of the conveying guide wire on the slope surface and the included angle of the conveying guide wire.

According to some specific embodiments of the present invention, wherein the end 163 of the sloped surface 162 close to the user is formed by a connecting grid 164, and the connecting grid is composed of two connecting links 165 and two supporting links 166, The two connecting links are part of the edge links, and the delivery guide wire 2 is connected with the intersection of the two connecting links 165 .

According to some specific embodiments of the present invention, the width of the support link 166 (w3 as shown in FIG. 5 ) is larger than the width w1 of the link 16 by 0.01-0.02 mm.

According to some specific embodiments of the present invention, the width w3 of the support link 166 is 0.06-0.11.

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

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

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

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

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

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

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

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

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

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

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

During delivery, the stent can be crimped into the introduction sheath or microcatheter under the action of an external force; when the binding external force of the introduction sheath or microcatheter disappears, the stent can self-expand into a complete tubular structure.

According to some specific embodiments of the present invention, the delivery guide wire 2 sequentially includes a first sizing section 21 , a first reducing section 22 , a second reducing section 28 , and a second sizing section from the end close to the user 23 and the third variable diameter section 24, the outer surfaces of the third variable diameter section and the second diameter reduction section are provided with a developing wire 25, and the outer surfaces of the developing wire 25 and the second diameter reducing section 28 are covered with high molecular polymer heat shrinkable tubes 26.

The first fixed diameter section 21 is connected to one end of the first diameter reduction section 22, the other end of the first diameter reduction section 22 is connected to one end of the second diameter reduction section 28, and the other end of the second diameter reduction section is connected to one end of the third diameter reduction section , the other end of the third diameter reducing section is connected with one end of the second sizing section, and the other end of the second sizing section is connected with the third diameter reducing section.

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

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 guide wire, and the lengths of the first reducing section 22 and the length of the second reducing section 28 are each independently for the delivery The length of the second sizing section 23 is 0.05-0.1 times the total length of the conveying guide wire, and the length of the third reducing section 24 is 0.03 times the total length of the conveying guide wire.

According to some specific embodiments of the present invention, the first diameter reducing section 22 is to change the diameter from the diameter of the first fixed diameter section 21 to 0.5-0.6 times the original diameter, and the second diameter reducing section 28 gradually changes the diameter to the first diameter. The diameter of the fixed diameter section 21 is 0.4-0.48 times, and the diameter of the third variable diameter section 24 is changed from the diameter of the second fixed diameter section 23 to 0.2 to 0.3 times the diameter of the first fixed diameter section.

According to some specific embodiments of the present invention, the first diameter reducing section 22 is to change the diameter from the diameter of the first fixed diameter section 21 to 0.56 times the original diameter.

According to some specific embodiments of the present invention, wherein, the diameter of the second diameter reducing section 28 gradually changes to 0.42 times the diameter of the first fixed diameter section 21 .

According to some specific embodiments of the present invention, the diameter of the third diameter reducing section 24 is changed from the second sizing section to 0.28 times the diameter of the first sizing section 21 .

It can be understood that the original diameter of the present invention refers to the diameter of each variable diameter section at the starting position, that is, the connection between the variable diameter section and the previous section (the previous fixed diameter section or the previous variable diameter section). diameter.

According to some specific embodiments of the present invention, the first diameter reducing section 22 changes the diameter from the diameter of the first fixed diameter section 21 to 0.56 times the original diameter, and the second diameter reducing section 28 changes the diameter from the original diameter to the first diameter. 0.42 times the diameter of the certain diameter section 21 .

The shape and structure of the delivery guide wire 2 of the present invention can refer to the prior art. 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 of the total length of the delivery guide wire. The distal end is designed to be tapered, and the length of the distal end is 0.3-0.4 times the total length of the delivery guide wire. There are three main diameter reduction designs at the distal end, the first one is connected to the proximal end, and the diameter gradually changes to the diameter of the proximal end. 0.56 times of the diameter of the guide wire, the gradient length is 0.1 times the total length of the delivery guide wire, followed by the second variable diameter section, the diameter gradually becomes 0.42 times the diameter of the proximal end, and the gradient length is 0.1 times the total length of the delivery guide wire. Connected to the second sizing section, the diameter gradually becomes 0.28 times the diameter of the first sizing section, and the length of the gradual change is 0.03 times the total length of the conveying guide wire.

The distal end of the delivery guide wire is designed with variable diameter, which is smaller in size and more flexible, and has a good guiding effect during surgery; the proximal end is designed with equal diameter, larger in size, stronger in rigidity, and can provide better transmission. The performance makes the whole thrombectomy device easier to reach the vascular lesions.

In the above thrombectomy device, preferably, the self-expanding stent is provided with a developing wire running through the entire length direction, so that the stent can clearly show its open state under X-ray.

The connection method between the self-expanding stent and the delivery guide wire may refer to the existing conventional connection method, such as bonding or welding the two.

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 third reducing section 24 of the delivery guide wire 2 and the developing wire 25 gaps between.

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 means of bonding or welding.

According to some specific embodiments of the present invention, a connecting sleeve 4 can also be disposed on the outer periphery of the connection between the connecting rod 167 and the delivery guide wire, and the connecting sleeve covers a part of the connecting rod 167 and the distal end of the delivery guide wire.

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

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

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

To sum up, the present invention provides a thrombectomy device. The thrombectomy device of the present invention has the following advantages:

Compared with the existing mechanical bolt removal technology, the design structure adopted in the present invention has the advantages that the wall thickness of the bolt removal bracket is greater than the rod width, and different parts have grids of different sizes, and these grids are arranged in the circumferential direction of the bracket. Helical arrangement, the large grid in the middle grabs or embeds most of the thrombus, and the distal end is in the same vertical plane, reducing the unnecessary length of the stent. The problem of secondary embolism caused by the distal end of the stent falling off. Increasing the widths of the proximal edge link 161 and the support link 166 can provide better transmission performance for the delivery of the thrombectomy. The width of 16 is the same. During the test, the push resistance is large. Later, the width of the edge link 161 is increased by 0.025-0.03mm, and the width of the support link 166 is increased by 0.01-0.02mm. During the test, the push resistance changed from being relatively smooth before to very smooth. The good transfer performance enables the stent to reach the diseased site smoothly and achieve accurate positioning; the whole-process imaging of the stent provides great convenience for the operation of the operation, and the operator can clearly observe the relative position of the stent and the thrombus, and the expansion state of the stent , which ensures more accurate and reliable thrombectomy process; the thrombectomy device of the present invention has a simple structure, the product has a smaller outer diameter after being pressed and has high flexibility, and can reach the tortuous diseased blood vessel more conveniently; the product is simple to operate, and It not only reduces the operator's workload, but also buys precious time for the patient's vascular recanalization.

Description of drawings

Fig. 1 is the overall schematic diagram of thrombectomy device;

Fig. 2 is the schematic diagram of the self-expanding stent of the thrombectomy device;

Fig. 3 is the schematic plan view of the self-expanding stent of the thrombectomy device;

Fig. 4 is the grid partial schematic diagram of self-expanding stent;

5 is a schematic diagram of the edge connecting rod of the proximal edge of the self-expanding stent;

Fig. 6 is a schematic diagram of the thrombectomy device delivering guide wire;

Fig. 7 is a schematic diagram of the introduction of the thrombectomy device into the sheath;

8 is a schematic diagram of the connection relationship between the self-expanding stent and the delivery guide wire of the thrombectomy device;

Figure 9a is a schematic diagram of a developing spring for connecting the thrombectomy bracket and the delivery guide wire;

Figure 9b is a schematic diagram of a developing ring for connecting the thrombectomy bracket and the delivery guide wire;

Figure 10 is a test chart of the push resistance test of the introduction of the thrombectomy device numbered Q201704214020002 into the sheath;

Figure 11 is a test chart of pushing resistance in a microcatheter numbered Q201704214020002;

Figure 12 is a test chart of the push resistance test of the introduction of No. Q201704214020005 into the sheath;

Fig. 13 is the test chart of pushing resistance in the microcatheter numbered Q201704214020005;

Figure 14 is a test chart of the push resistance test of the introduction of No. Q201705114020001 into the sheath;

Figure 15 is a test chart of pushing resistance in a microcatheter numbered Q201705114020001;

Figure 16 is a test chart of the push resistance test of the introduction of the number Q201707044020002 into the sheath;

Fig. 17 is a test chart of pushing resistance in a microcatheter numbered Q201707044020002;

Figure 18 is a test chart of the push resistance test of the introduction of No. Q201707044020004 into the sheath;

Figure 19 is a test chart of pushing resistance in a microcatheter numbered Q201707044020004.

Detailed ways

The implementation process and beneficial effects of the present invention are described in detail below through specific examples, which are intended to help readers better understand the essence and characteristics of the present invention, and are not intended to limit the scope of implementation of the present case.

Example 1

For ease of description, the following description uses the terms "proximal end" and "distal end", where "proximal end" refers to the end close to the operator and distal end refers to the end away from the operator.

Fig. 1 is a thrombectomy device, comprising 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 means of welding, bonding, pressing, etc. through a developing ring or a developing spring, Figure 1 shows the state after the stent is released and deployed; the assembled thrombectomy product is the stent and the delivery guide wire being pressed and held in the introducer sheath.

Figures 2 and 3 are stent grids. The area of the sparse grids 12 in the middle section 14 of the stent is significantly larger than the areas of the proximal 15 grids and the distal 13 grids, and the area of the middle section grids is the same as that of the proximal and distal grids. The length of the middle section of the sparse grid accounts for half of the total length of the stent, the length ratio of the proximal end and the distal end is 1:1, and the total length of the stent is 35mm; the distal grid is arranged at least one in the circumferential direction. Circulation; at least one of the proximal grids is located at the bifurcation of the proximal ramp opening of the stent. In this way, the large middle grid can be used as the main thrombectomy part to capture or embed most of the thrombus; the distal grid is used to capture the smaller thrombus, thereby preventing the thrombus captured by the grid from slipping off the distal end of the stent and causing secondary thrombus. The problem of secondary embolism; when the thrombectomy device is delivered, the mesh at the proximal end can transmit the operator's pushing force from the delivery guide wire to the stent, so that the thrombectomy stent can reach the lesion smoothly.

The skeleton of the stent in Fig. 2 and Fig. 3 runs through the developing ring from the proximal end to the distal end. This ring is made of X-ray opaque material, which is beneficial to determine the relative position of the stent and the thrombus, and facilitates observation of the stent during surgery. The open shape of the stent also ensures the degree of binding between the stent and the thrombus.

FIG. 3 is a schematic diagram of the winding position of the stent developing ring. The entire stent includes 9 developing points, and the 9 developing points can construct the outer diameter and limited length of the stent.

Figure 4 is a partial enlarged view of the mesh of the stent; Figure 5 is an enlarged view of the edge link 161 at the proximal edge (this figure only shows the edge link and the corresponding link connecting the mesh, which is omitted for clarity other meshes and corresponding connecting rods). Wherein, a section of the edge link 161 close to the delivery guide wire serves as a link (ie, the connecting link 165 ) forming the connecting grid 164 . The width w3 of the support link 166 is larger than the width w1 of the link 16 by 0.02 mm.

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 forming the grid 12 , and the width w1 of the connecting rods 16 forming the grid 12 is 0.08. The width w2 of the edge link 161 is 0.028 mm greater than the width w1 of the link 16 at the non-proximal edge of the self-expanding stent.

The edge link 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°.

FIG. 6 is a schematic diagram of the thrombus removal device conveying the guide wire 2 , which is mainly composed of a core wire, an X-ray opaque developing spring 25 and a high molecular polymer heat shrinkable tube 26 . The core wire is made of soft and rigid variable-diameter wire material, which not only ensures the support and transmission performance of the thrombectomy device, but also provides a certain degree of flexibility, which is conducive to the smooth passage of the stent through tortuous blood vessels and lesions parts, to achieve accurate positioning.

The delivery guide wire 2 is sequentially divided into a first sizing section 21, a first reducing section 22, a second reducing section 28, a second sizing section 23 and a third reducing section 24 from the end close to the user. A developing spring 25 is provided on the outer surfaces of the second sizing section and the third diameter reducing section, and the outer surfaces of the developing spring 25 and the second diameter reducing section 28 are covered with a high molecular polymer heat shrinkable tube 26 . The length of the first fixed diameter section 21 is 0.57 times the total length of the conveying guide wire, the lengths of the first reducing diameter section 22 and the second reducing diameter section 28 are respectively 0.15 times the total length of the conveying guide wire, and the length of the second diameter adjusting section It is 0.1 times the total length of the delivery guide wire, and the length of the third variable diameter section is 0.03 times the total length of the delivery guide wire. The first variable diameter section 22 changes the diameter from the diameter of the first fixed diameter section 21 to 0.56 times the original diameter, the second variable diameter section 28 changes the diameter to 0.42 times the diameter of the first fixed diameter section, and the third variable diameter section The diameter of the segment 24 is changed from the diameter of the second sizing segment 23 to 0.28 times the diameter of the first sizing segment.

Fig. 7 shows the introduction sheath tube 3, which is an extruded tube made of high molecular polymer material with a small friction coefficient, which not only protects the stent during packaging and ensures its stability, but also is more conducive to removing the embolectomy device during surgery. Introduced into the microcatheter to achieve the purpose of rapid delivery.

Figures 9a and 9b show two devices with different structures, which can be used for the connection of a stent to a delivery guide wire. Fig. 9a is the developing spring, Fig. 9b is the developing ring, the connection method is to place the connecting rod 167 of the self-expanding stent and the third reducing section 24 of the conveying guide wire in the developing spring 9a or the developing ring 9b (as shown in Fig. 8 ) ) and then connect the two by welding, gluing or crimping. Both the developing spring 9a and the developing ring 9b are made of X-ray opaque material, which is beneficial to the accurate positioning of the stent and improves the success rate of the operation.

test case

Table 1. Dimensions of the bracket to be tested

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

System compliance, pushability and pullback performance testing

Test method: The test is carried out in accordance with the "Test Method for Push, Compliance and Retraction of Thrombus Retriever".

Acceptance criteria: The stent should be able to be pushed along the lumen of the introducer sheath and microcatheter in the simulated blood vessel model, and should be able to reach the designated marked position without being bent or folded, and the pushing force during the process should be ≤150gf. See Figures 10-19 for graphs.

The test results are shown in Table 2:

Table 2. Performance test of thrombectomy device

It can be seen from Table 2 that the thrombectomy devices of all sizes can reach the target position along the introducer sheath or microcatheter, and the compliance is qualified; However, the flexibility, pushing and retracting properties of the products numbered Q201704214020002 and Q201704214020005 are all worse than those of the products of the present invention. The thrombectomy device of the present invention can have more excellent operating performance.

Claims (10)

1. a thrombectomy thrombectomy device, the thrombectomy device comprises a cylindrical self-expanding stent (1) open at both ends, a delivery guide wire (2) and an introduction sheath (3), wherein the self-expanding stent The wall (11) 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 segment ( 14) and the distal end (13); the single grid area of the middle section (14) grid (preferably the single grid area of the middle section grid is 7-13 mm ² ; more preferably 10 mm ² ) is larger than the distal end (13) and the single mesh area of the proximal end (15), a smooth edge link (161) is provided at the proximal edge of the self-expanding stent (1), and the wall thickness ratio of the self-expanding stent is non-proximal to form the mesh (12). The width of the connecting rods (16) at the end edges is 0.01-0.04 mm (preferably 0.02 mm larger) (preferably the width of the connecting rods (16) forming the grid (12) is 0.05-0.09 mm). 2. The thrombectomy thrombectomy device 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) (preferably the distal end of the self-expanding stent (1) The length ratio of the end (13) and the proximal end (15) is 1:1-1:2 (preferably 1:1)) (preferably the length of the self-expanding stent (1) is 28.0-42.0 mm). 3. The thrombectomy device according to claim 1, wherein the ratio of the single mesh area of the middle section (14) to the proximal end (15) of the self-expanding stent (1) is 2:(0.5-1.5) (preferably 2:1); the individual mesh area ratio of the proximal (15) and distal (13) ends is 1:1 to 1.9:1. 4. The thrombus retriever according to claim 1, wherein the width of the edge links (161) is 0.01-0.03 mm greater than the width of the links (16) at the non-proximal edge of the self-expanding stent. 5. The thrombectomy device according to claim 1, wherein the edge connecting rod (161) forms a slope (162) relative to the delivery guide wire (2) (preferably the delivery guide wire (2) and the slope surface) The included angle α of (162) is 135°-150°). 6. The thrombectomy device according to claim 5, wherein the end (163) of the ramp (162) close to the user is formed by a connecting grid (164) consisting of two connections A connecting rod (165) and two supporting connecting rods (166) are formed, the two connecting connecting rods belong to a part of the edge connecting rods, and the conveying guide wire (2) is connected with the intersection of the two connecting connecting rods (165) ( Preferably, the width of the support link (166) is 0.01-0.02mm larger than the width of the link (16). 7. The thrombectomy device according to claim 1, wherein the delivery guide wire (2) is made of metal, preferably an alloy of nickel and/or titanium. 8. The thrombectomy device according to claim 1, wherein the introduction sheath (3) is made of high molecular polymer (preferably polytetrafluoroethylene). 9. The thrombectomy device according to claim 1, wherein the self-expanding stent (1) is made of memory alloy (preferably Nitinol) (preferably laser-cut from memory alloy). 10. The thrombectomy device according to claim 1, wherein the delivery guide wire (2) sequentially comprises a first fixed diameter section (21), a first reduced diameter section (22), The second diameter reduction section (28), the second diameter reduction section (23) and the third diameter reduction section (24), the outer surfaces of the second diameter reduction section and the third diameter reduction section are provided with developing wires (25) (preferably the The developing wire is spring-shaped or developing ring), and the outer surface of the developing wire (25) and the second diameter reducing section (28) is covered with a high molecular polymer heat shrinkable tube (26) (preferably the first diameter section (21) The length of the guide wire is 0.6-0.7 times the total length of the delivery guide wire, and the lengths of the first variable diameter section (22) and the second variable diameter section (28) are independently 0.1-0.2 times the total length of the delivery guide wire. The length of the sizing section is 0.05-0.1 times the total length of the conveying guide wire, and the length of the third reducing section is 0.03 times the total length of the conveying guide wire (preferably, the first reducing section (22) is the diameter from the first sizing section. The diameter of (21) becomes 0.5-0.6 times the original diameter (preferably 0.56 times), and the second diameter reducing section (28) changes the diameter from the diameter of the first constant diameter section (21) to 0.4-0.48 the original diameter times (preferably 0.42 times), the third diameter reducing section (24) changes the diameter from the diameter of the second sizing section (23) to 0.2-0.3 times (preferably 0.28 times) the diameter of the first sizing section).