Self-expanding anchoring and bolt taking systemTechnical Field
The invention relates to the field of medical instruments, in particular to a self-expanding anchoring thrombus taking system.
Background
Thrombosis is the term for intravascular blood clot formation, and venous thrombosis is a blood clot (thrombus) formed intravenously. A common type of venous thrombosis is Deep Vein Thrombosis (DVT), which is primarily a blood clot (thrombus) formed in the deep veins of the leg. Non-specific signs may include pain, swelling, redness, fever, and engorged superficial veins. If the thrombus breaks off (embolizes) and flows to the lungs, it may become a life threatening Pulmonary Embolism (PE). In addition to the loss of life that may be caused by the PE, DVT may also cause significant health problems.
Interventional therapeutics (also known as interventional radiology) refers to the general term of a series of techniques for performing minimally invasive treatment by introducing specific instruments into a lesion site of a human body through natural ducts or tiny wounds of the human body by using puncture needles, catheters and other interventional instruments under the guidance and monitoring of imaging equipment such as digital subtraction angiography, CT, ultrasound, magnetic resonance and the like.
The most common methods of interventional therapy are mechanical thrombolysis, arterial and venous thrombolysis, and balloon dilation.
Mechanical thrombus extraction is carried out to guide a catheter to establish a conveying channel, a thrombus extraction bracket is conveyed to a neurovascular embolism part, and after the thrombus extraction bracket is released, thrombus is cut and retracted through the thrombus extraction bracket, and the thrombus extraction effect is achieved under the action of suction; compared with the traditional operation, the mechanical thrombus taking has the advantages of quick operation, suitability for acute patients, short preparation time before operation, quick postoperative recovery and the like.
Intravascular intervention has become a trend in intravascular treatment of diseases today, but effective intervention means for treating acute pulmonary embolism patients are not clinically available at present. The existing products for treating vascular embolism in the market mainly aim at clinical application with small vessel diameter and small thrombus amount, such as intracranial artery, coronary artery, lower limb artery and the like, and pulmonary artery treatment faces the problems that the vessel diameter is large, thrombus amount is large, the existing products for removing thrombus in other vessels cannot be suitable or have very low effect, and the existing interventional products mainly adopt thrombolysis catheter treatment, so that the rapid removal of a large amount of thrombus is difficult to effectively solve.
And in clinic, 10% -20% of patients cannot realize successful vascular occlusion recanalization, wherein the escape of thrombus during operation is the most common cause of incomplete vascular recanalization.
On the one hand, escaped thrombus can block side branch circulation, influence blood flow perfusion of ischemic penumbra tissues, and finally lead to increased infarct volume; on the other hand, thrombus escape may involve previously unaffected vascular watershed, triggering new infarct foci (INFARCT IN NEW territory, INT), which in turn affect the clinical outcome of mechanical thrombolytic therapy.
There are two main reasons why many thrombus removal devices currently on the market cause thrombus to escape during use. One is that the current thrombus taking support is mostly a nickel titanium wire woven net cage, and the radial supporting force of the woven support is smaller, and the thrombus is easy to be deformed by thrombus pressure when encountering thrombus. The axial section of the disc and the smooth braided wires enable the friction force between the stent and the thrombus contact part to be small, and many times doctors can see that the stent catches thrombus under an image system, but the caught thrombus slips off from the surface of the stent because the thrombus and the vessel wall are seriously calcified in the stent retracting process. So that the thrombus either continues to adhere firmly to the vessel wall, the stent does not build up force to carry it away, or the thrombus slides directly off the surface of the attached stent as the stent is withdrawn and flows deep into the vessel as the blood flow progresses.
Another reason is that some soft emboli are cut into small pieces by the braided wires as the stent is released and withdrawn into the aspiration tube, and these small pieces are smaller than the stent mesh and escape directly from the mesh and into the deep vessel. Or from the deformed stent disk and vessel gap. At present, the stent design scheme with the tectorial membrane can effectively block broken bolts. However, the coating on the woven stent is difficult to realize, the manufacturing cost is high, and the coating structure can cause the difficult pushing of the stent in the conveying system and the rupture failure of the coating in the pushing process. Because the tectorial membrane does not have any mesh, after opening completely in the blood vessel, whole system of taking out is the state of separation blood flow in the blood vessel, can influence patient's operation time blood backward flow, and in operation take out thrombus back in-process, can directly take out whole blood in the blood vessel of whole section, easily cause patient's massive hemorrhage.
Therefore, the person skilled in the art is dedicated to develop a self-expanding anchoring thrombus taking system, which can solve the technical problems of insufficient thrombus support strength, easy falling off after thrombus taking off and broken thrombus escaping existing in the current thrombus taking device.
Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, the present invention provides a self-expanding anchoring and bolt-taking system, which includes a bolt-taking bracket, a bolt-breaking collecting device and a conveying device, wherein the bolt-taking bracket includes a first bracket net cage at a proximal end and a second bracket net cage at a distal end which are connected in series, two ends of the first bracket net cage and the second bracket net cage are connected with connecting net cages, the diameter of the connecting net cage is smaller than that of the first bracket net cage and the second bracket net cage, the first bracket net cage and the second bracket net cage are fixedly connected through the connecting net cage, the parallel radial section shape of the first bracket net cage and the second bracket net cage is in a calabash shape, and the parallel axial section shape of the first bracket net cage and the second bracket net cage is in a petal shape; the conveying device comprises an outer pipe and an inner pipe, the outer pipe is a hollow circular pipe, the outer pipe is sleeved outside the inner pipe, and the inner pipe can smoothly stretch out and draw back in the outer pipe; the broken bolt collecting device is positioned at the far end of the inner tube and is a protective umbrella; the thrombus taking support is fixedly connected to the outside of the conveying device, the far end of the thrombus breaking collecting device is fixedly connected to the far end of the inner tube, and the near end of the thrombus breaking collecting device is connected to the far end of the thrombus taking support.
Further, the first support cylinder mould the second support cylinder mould and the connection cylinder mould are double-deck woven cylinder mould, the first support cylinder mould with the size, the shape of second support cylinder mould are the same, the first support cylinder mould is high density woven cylinder mould, the second support cylinder mould is low density woven cylinder mould, the first support cylinder mould with the petal shape, size and the number of petal recess and the support lamella of second support cylinder mould are the same.
Further, the petal-shaped concave grooves of the first bracket net cage and the second bracket net cage and the connecting net cage are wound with barb wires, and the surfaces of the barb wires are covered with tiny barbs.
Further, the barbed wire is made of a medical polymer material wire, and specifically is one of a medical collagen wire, polydioxanone, polyglycolide and polylactide.
Further, the petal-shaped concave grooves of the first support net cage and the second support net cage are designed in a staggered mode relatively, and the sizes and the numbers of the first support net cage and the second support net cage are adjusted along with different blood vessels and the size of the prejudging thrombus.
Further, in an axial view, the protruding support petals of the second support net cage just fill the concave groove part of the first support net cage.
The inner layer of the first support net cage and the inner layer of the second support net cage are woven in a high-density mode, the outer layer of the first support net cage and the second support net cage are woven in a low-density mode, and the first support net cage, the second support net cage and the connecting net cage are made of nickel-titanium alloy.
Further, a developing ring is arranged at the joint of the thrombus taking support and the proximal end of the outer tube, the outer tube is formed by splicing multiple sections of materials with different hardness, and the hardness of the multiple sections of materials with different hardness is gradually reduced from the proximal end to the distal end.
Further, the outer tube and the inner tube are made of polymer materials and are made of single materials or composite materials. The inner tube is directly sleeved in the outer tube, is connected with the outer tube in a drawing mode, and can axially and freely move.
Further, the protection umbrella is an umbrella-shaped support woven by high-density meshes, the proximal end of the protection umbrella is connected with the connecting net cage at the distal end of the thrombus taking support, the distal end of the protection umbrella is fixed on the distal end of the inner tube and is released and contracted together with the thrombus taking support, the distal end of the protection umbrella is connected with a developing cap, the developing cap is made of a high polymer material, and the head of the developing cap is provided with a cone angle.
Further, the protective umbrella is connected to the distal end of the inner tube by a separate movable mechanism, and is kept in an open state until the suction catheter is retracted.
In a preferred embodiment of the invention, the knitting density of the first bracket netpen, the second bracket netpen and the protective umbrella are ordered as follows: the protection umbrella is highest, and first support cylinder mould is inferior, and the second support cylinder mould is lowest. The braid density is generally represented by PPI, the proposed density of the present invention is: the PPI of the protective umbrella is 70-100; the PPI of the first bracket net cage is 30-70; the PPI of the second bracket net cage is 10-30. Meanwhile, the density of the braiding structure can be flexibly adjusted according to the use position so as to adapt to different blood vessels. Through the improvement to the thrombus taking support, the thrombus taking support is designed into a plurality of double-layer woven support net cage series structures, so that the whole thrombus taking support has better radial supporting force, is not easy to be deformed by thrombus compression in a blood vessel, has better thrombus cutting effect and greatly increases axial tension. When the stent is slowly released at the thrombus position, the whole thrombus can be fully concentrated and pressed towards the axial center direction of the stent by good axial rebound, and the thrombus is firmly held by the front and rear stent net cages; different series-connected net cages have different weaving densities, so that the stent can adapt to the bending and diameter sizes of different blood vessels, can be fully attached to the wall of the blood vessels, and can be more uniformly adhered to the whole thrombus.
The petal-shaped three-dimensional net cage knitting structure can increase the contact area between the bracket net cage and thrombus. On the one hand, the medical silk threads which are fully distributed with barbs are wound on the connecting net cage between the concave groove and the bracket net cage, so that thrombus can be firmly anchored in multiple directions, and any movement of the thrombus can be prevented. On the other hand, the protruding stent-graft can well support the vessel wall, so that the barbs in the collecting groove are not contacted with the vessel wall, and the vascular injury caused by friction between the barbs and the vessel wall in the stent withdrawing process is prevented. The protruding stent petals can also well clamp thrombus, so that the contact surface between the stent net cage and the thrombus is prevented from slipping due to axial circumferential rotation of the net cage in the retracting process of the conveying catheter.
The design of the protective umbrella is woven at the far end of the bracket in a high density, broken bolts escaping from the process of taking bolts by the net cage of the bracket at the near end can be collected, and blood flow can flow away from the woven holes of the protective umbrella, so that the normal flow of the blood flow in the operation process is not influenced. The independent movable structure of the proximal net cage can ensure that the protective umbrella is kept in a good opening state from the beginning of the thrombus taking process to before the suction tube is retracted, ensure that all thrombus and thrombus fragments can be captured by the protective umbrella before the bracket is completely retracted, and greatly reduce the bleeding during operation. The protective umbrella is connected to the far end of the inner tube through an independent movable mechanism, the near end of the protective umbrella is connected with the outer tube, the far end of the protective umbrella is connected with the inner tube, and the inner tube is sleeved in the outer tube and can axially and freely move. This is equivalent to a attenuator, guarantees that the protection umbrella can be through this kind of movable structure adjusts self adaptive force, keeps a good open condition in the thrombus extraction system back removes the thrombus extraction in-process. The thrombus is prevented from escaping from the gap between the deformed protective umbrella and the blood vessel because the external force is too large to pull and deform directly. Compared with a fixed movable mechanism (equivalent to the protection umbrella and the net cage are directly connected to the outer tube), the protection umbrella is easy to be directly pulled and deformed in the process of withdrawing along with the thrombus taking system.
In another preferred embodiment of the invention, one to two platinum-tungsten or other developing alloy wires can be doped in all the woven stent nettings, and all the sections are woven in, so that the whole stent can be developed by the design of weaving, and a doctor can visually see the state of the whole stent through an imaging system during operation.
Compared with the prior art, the invention has the following beneficial technical effects:
1. the thrombus taking support is designed into a plurality of double-layer woven supports in series, so that the whole thrombus taking system has better radial supporting force, is not easy to be deformed by thrombus pressure in a blood vessel, has better thrombus cutting effect, greatly increases axial tension, and has good axial rebound resilience matched with a gourd-shaped section, so that the whole thrombus can be completely concentrated and pressed towards the axis direction of the support.
2. Different series-connected net cages have different weaving densities, so that the stent can adapt to the bending and diameter sizes of different blood vessels, can be fully attached to the wall of the blood vessels, and can be more uniformly adhered to the whole thrombus.
3. The petal-shaped three-dimensional net cage knitting structure can increase the contact area between the bracket net cage and thrombus; the protruding stent petals can clamp thrombus, so that slipping of the contact surface of the stent net cage and the thrombus caused by axial circumferential rotation of the net cage in the catheter withdrawing process is prevented.
4. Medical silk threads full of barbs are wound on the woven mesh between the concave grooves and the net cage, so that thrombus can be firmly anchored in multiple directions, and the thrombus is prevented from moving. The protruding stent-graft can uniformly support the vessel wall, so that the barbs in the collecting groove are not contacted with the vessel wall, and the vascular injury caused by friction between the barbs and the vessel wall in the stent withdrawing process is prevented.
5. The design of the protective umbrella is woven at the far end of the bracket in a high density manner, broken bolts escaping from the process of taking bolts by the net cage of the bracket at the near end can be collected, blood flow can normally flow from the woven meshes of the protective umbrella in the process of operation, the blood flow state of a patient is not influenced, and the bleeding amount of the operation can be greatly reduced. The independent movable structure of the proximal net cage can ensure that the protective umbrella keeps a good opening state from the beginning of thrombus taking to before the suction tube is retracted, and ensure that all thrombus and broken thrombus can be captured by the protective umbrella before the bracket is completely retracted.
6. Compared with the existing mechanical thrombus taking mode, the self-expanding anchoring thrombus taking bracket is convenient to operate, safe, reliable and high in success rate, good in radial supporting force can be used for pulmonary artery thrombus taking with a large diameter, and the variable-density woven structure can flexibly adjust the bracket structure according to the using position so as to adapt to different blood vessels.
The conception, specific structure, and technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, features, and effects of the present invention.
Drawings
FIG. 1 is a general view of a self-expanding anchor extraction system according to a preferred embodiment of the present invention;
FIG. 2 is a graph showing the effect of the change in density of a self-expanding anchor extraction system according to one preferred embodiment of the present invention;
FIG. 3 is a schematic illustration of a self-expanding anchor stent-retrieval system with a bare stent according to a preferred embodiment of the present invention;
FIG. 4 is an axial view of first and second stent nettings of a preferred embodiment of the present invention;
Figure 5 is a schematic view of the barb distribution areas of a preferred embodiment of the present invention;
FIG. 6 is an axial schematic view of first and second stent mesh cage anchoring thrombi in accordance with a preferred embodiment of the present invention;
FIG. 7 is a schematic illustration of an entire self-expanding anchor stent system anchoring thrombus in accordance with a preferred embodiment of the present invention;
Figure 8 is a schematic view of a barbed wire according to a preferred embodiment of the present invention;
FIG. 9 is a schematic illustration of the insertion of a self-expanding anchor retrieval system into a delivery catheter in accordance with a preferred embodiment of the present invention;
FIG. 10 is a schematic view of a self-expanding anchor retrieval system according to a preferred embodiment of the present invention, through a vascular embolic site;
fig. 11 is an axial view of the first and second stent mesh cages of a preferred embodiment of the present invention in a relatively staggered design.
In the figure: 1-a first bracket net cage; 2-a second bracket net cage; 3-protecting umbrella; 4-connecting a net cage; 5-developing cap; 6-developing ring; 7-barb wires; 8-stent petals; 9-a concave groove; 10-an outer tube; 11-an inner tube; 12-a delivery catheter; 13-large thrombi; 14-breaking the thrombus; 15-barbs.
Detailed Description
The following description of the preferred embodiments of the present invention refers to the accompanying drawings, which make the technical contents thereof more clear and easy to understand. The present invention may be embodied in many different forms of embodiments and the scope of the present invention is not limited to only the embodiments described herein.
In the drawings, like structural elements are referred to by like reference numerals and components having similar structure or function are referred to by like reference numerals. The dimensions and thickness of each component shown in the drawings are arbitrarily shown, and the present invention is not limited to the dimensions and thickness of each component. The thickness of the components is exaggerated in some places in the drawings for clarity of illustration.
Example 1
As shown in fig. 1, 2 and 3, a schematic diagram of a self-expanding anchor thrombolysis system is provided. The thrombus taking support consists of a plurality of double-layer woven support series structures, and comprises a connecting net cage 4, a first support net cage 1, a connecting net cage 4, a second support net cage 2 and a connecting net cage 4 from the near end to the far end. The outer tube 10 and the inner tube 11 are used in cooperation, and the inner tube 11 can smoothly stretch and retract in the outer tube 10. The protective umbrella 3 is individually connected to the distal end of the inner tube 11, and the proximal end of the protective umbrella 3 is connected to the front second bracket net cage 2 through the connecting net cage 4. The independent movable mechanism can ensure that the protective umbrella 3 can not be influenced by the contraction, the movement and the like of the proximal net cage in the process of retracting after being completely released, so that the shape of the protective umbrella is changed. So that the protective umbrella 3 remains well open until the suction tube is retracted, so that it is able to fully catch all proximally escaping pins 14. The outer tube 10 is made of a polymer material, and may be made of a single material or a composite material. The outer tube 10 is formed by splicing multiple sections of materials with different hardness, and the hardness of the multiple sections of materials with different hardness is gradually reduced from the proximal end to the distal end, so that the outer tube 10 is guaranteed to have good pushing performance, and meanwhile, the distal end is good in flexibility. The connection part of the outer tube 10 and the thrombus taking support is provided with a developing ring 6 which is used for positioning the proximal end of the support by a doctor under an imaging system; the inner tube 11 is made of a polymer material, can be made of a single material or a composite material, and can move in the outer tube 10; The first support net cage 1, the second support net cage 2, the connecting net cage 4 and the protective umbrella 3 of the self-expanding anchoring thrombus taking support are all made of nickel-titanium alloy materials, have a good memory function, can be opened and expanded at a release position by oneself, do not need to be expanded by a balloon, can reduce operation steps of doctors, and can also reduce consumable medical expenses of patients. The original shape of the special-shaped stent can be maintained in a tortuous blood vessel after the stent is opened, and the special-shaped stent can be smoothly recovered in the operation process without any deformation; the whole bracket part is knitted in double layers, and the knitting method is mature at present. The double-layer braiding can greatly increase the radial supporting force of the bracket. Particularly, a blood vessel with a very large diameter like a pulmonary artery is thick in vessel wall, and a common single-layer woven stent is easily deformed by the blood vessel and thrombus due to insufficient radial supporting force of the stent. It is also difficult to scrape off some thrombus that adheres tightly to the blood vessel. But the double layer weave structure solves this problem well. Meanwhile, the weaving densities of the first bracket net cage 1 and the second bracket net cage 2 are different (as shown in figure 2), the first bracket net cage 1 is woven by high-density double-layer meshes, and can provide a good guiding supporting force for a blood vessel at the proximal end, and the thrombus is firstly cut and scraped off by being stressed in the process of withdrawing the bracket, so that the received force is the largest; the second support cylinder mould 2 is woven for low-density double-layer meshes, and the inner layer provides enough vascular supporting force and simultaneously the outer loose meshes enable the support to become more flexible, so that the support can adapt to more curved and complex vascular structures, the vascular wall can be uniformly attached in the support withdrawing process, and the thrombus can be prevented from escaping from deformation gaps. The protective umbrella 3 is an umbrella-shaped bracket woven by ultra-high density meshes, and blood flow can flow out of the woven holes of the protective umbrella, but broken plugs can be filtered out by the meshes. The proximal end of the protective umbrella 3 is connected with a woven net cage, and the distal end is fixed on the inner tube and can be released and contracted together with the bracket net cage. But the independent movable structure of the inner tube can prevent the protection umbrella 3 from being greatly influenced in the recovery and movement process of the front end net cage support. The parallel radial section shapes of the first bracket net cage 1 and the second bracket net cage 2 are gourd-shaped (figure 3), two ends of the structure are expanded, the middle is tiny, thrombus can be grasped and extruded and gathered towards the thin end in the opening process of the bracket, the thrombus is firmly attached to the axis direction and firmly held by the front and rear net cages, and the thrombus is not easy to slide and escape in the retracting process of the bracket. The parallel axial sections of the first bracket net cage 1 and the second bracket net cage 2 are petal-shaped (figure 4), and the protruding bracket petals 8 and the concave grooves 9 can firmly clamp thrombus at radial positions, so that the contact area with the thrombus is increased. Can avoid the phenomenon of thrombus and stent slipping caused by axial circumference self-transmission in the stent withdrawing process.
As shown in fig. 4 and 5, the barbed wire 7 is wound around both the concave grooves of the first bracket netpen 1 and the second bracket netpen 2 and the connecting netpen 4, and fig. 6 and 7 show a state in which the self-expanding anchoring thrombus extraction system is simulated to extract a thrombus, and the large thrombus 13 is firmly fixed between the first bracket netpen 1 and the second bracket netpen 2. The big thrombus 13 is firmly attached to the connecting net cage 4, and part of the small broken thrombus 14 is collected by the protective umbrella 3. As shown in fig. 8, tiny barbs 15 are distributed on the barb wires 7, and winding modes can be adjusted according to different blood vessels and different pathological change positions on the concave grooves 9 of the first bracket net cage 1 and the second bracket net cage 2 and the connecting net cage 4, so that the barbs 15 are pricked into a large thrombus 13 in the bracket releasing process (as shown in fig. 6 and 7). The number of the barbs is large, the large thrombus 13 can be pricked into the large thrombus 13 from different directions, and the large thrombus 13 can be firmly anchored, and the calabash-shaped net cage structure of the first bracket net cage 1 and the second bracket net cage 2 is added, so that the large thrombus 13 is extruded in the concave groove 9, which is equivalent to that the large thrombus 13 is always pressed in the barbs by always pushing force, and therefore, even if the bracket is retracted and recycled into the suction catheter, the large thrombus 13 is firmly anchored without any displacement. On the other hand, because the stent can firmly anchor the thrombus in the retracting process, the thrombus can be easily removed only by slightly applying a retracting force to the proximal end of the thrombus which is relatively intractable and adhered to the vessel wall or calcified, and the stent net cage of the thrombus taking system does not need to slip off from the thrombus. The support petals 8 on the first support net cage 1 and the second support net cage 2 are of an axial expansion structure, can be well attached to the wall of a blood vessel, and can separate the barb wires 7 in the concave groove 9 and on the connecting net cage 4 from the wall of the blood vessel while providing stable supporting force of the blood vessel, so that damage or other inflammatory reactions caused by scraping the blood vessel by the barbs 15 are avoided. The material of the barb wires 7 may be, but is not limited to, medical polymer material wires, such as medical collagen wires, polydioxanone, polyglycolide, polylactide, etc. (currently, medical wires with barbs are available on the market). The developing cap 5 is made of a polymer material and can perform a developing function. The head end of the stent is provided with a cone angle, so that the stent can conveniently guide the delivery tube to enter thrombus to provide a passage for stent release.
Fig. 9 is a schematic view of the insertion of the self-expanding anchoring and tie-down system into the delivery catheter, with both the first and second stent nettings 1,2 and the protective umbrella 3 in a contracted state. In use, the self-expanding anchor retrieval system is inserted into a delivery catheter and the delivery catheter is inserted through a penetrating blood vessel to and through the vascular occlusion site (as shown in fig. 10). As shown in fig. 7, the self-expanding anchor and thrombus removal system is released, so that the self-expanding anchor and thrombus removal stent nettings 1 and 2 are fully contacted with the large thrombus 13, and the large thrombus 13 is pressed against the concave groove 9 and the connecting nettings 4. The protective umbrella 3 is fully opened, stuck to the vessel wall, and the umbrella-shaped funnel catches the dropped broken peg 14. Finally, the self-expanding anchored embolectomy system is withdrawn along with the delivery catheter 12 to achieve the embolectomy effect.
Example 2
A self-expanding anchor retrieval system having the same overall structure as in example 1. The difference is that the concave grooves of the first bracket net cage and the second bracket net cage are designed in a staggered way (as shown in figure 11). For example, the number of pairs of the concave grooves 9 and the supporting petals 8 of the first stent mesh cage may be N pairs (n=2, 3,4,5, 6, 7 or 8), and the number of concave grooves 9 and the supporting petals 8 of the second stent mesh cage 2 is the same as the first stent mesh cage 1. The offset angle between the center position of the concave groove of the second bracket net cage 2 and the center position of the concave groove of the first bracket net cage can be selected to be 0-180 degrees/N. Optimally, the center position of the concave groove of the second bracket net cage 2 is staggered from the center position of the concave groove of the first bracket net cage 1 by 180 degrees/N.
Example 3
A self-expanding anchor retrieval system having the same overall structure as in example 1. The difference is that the number of the first bracket net cage and the second bracket net cage is not fixed, the thrombus size is adjusted along with the prejudgment, and larger and longer thrombus can be taken out by more net cages. The size of the netpen is adjusted according to the thickness of the blood vessel.
Example 4
A self-expanding anchor retrieval system having the same overall structure as in example 1. The difference is that the inner and outer layer braiding density of all braiding structures (comprising a first bracket net cage, a second bracket net cage and a connecting net cage) can also be adjusted according to different adaptation blood vessels and thrombus. For example, for some soft emboli, the blood vessel is relatively curved, the netpen stent can be designed to provide radial support force for the inner layer high-density braiding, and the outer layer low-density braiding improves the flexibility of the stent, so that the stent is uniformly attached to the blood vessel.
Example 5
A self-expanding anchor retrieval system having the same overall structure as in example 1. The difference is that one to two platinum tungsten or other developing alloy wires can be doped in all the braided stents of the self-expanding anchoring thrombus taking system, and the whole section is braided in, so that the true stent can be developed by the braiding design, and the doctor can intuitively see the state of the whole stent through an image system during operation.
The foregoing describes in detail preferred embodiments of the present invention. It should be understood that numerous modifications and variations can be made in accordance with the concepts of the invention without requiring creative effort by one of ordinary skill in the art. Therefore, all technical solutions which can be obtained by logic analysis, reasoning or limited experiments based on the prior art by the person skilled in the art according to the inventive concept shall be within the scope of protection defined by the claims.