A cutting device for thrombectomy

Abstract

The application discloses a cutting thrombus taking device, and relates to the field of medical devices, which comprises a conveying pipe, an intermediate pipe, an inner pipe, a thrombus taking mechanism and a developing cap. The intermediate pipe is located at the proximal end of the device, and the developing cap is located at the distal end of the device. The developing cap is provided with a developing function, so that the thrombus taking mechanism can be clearly observed under an imaging equipment. The thrombus taking mechanism is located between the intermediate pipe and the developing cap in the conveying pipe. The thrombus taking mechanism can be completely compressed in the conveying pipe, has a memory function, and can be freely contracted and opened to recover to the original state. The thrombus taking mechanism comprises a thrombus taking support, a cutting bag and a collecting bag. The thrombus taking support has a cutting wire with a rectangular cross section, can separate and pick up the thrombus from the blood vessel wall, the cutting bag collects the large thrombus cut by the thrombus taking support and performs secondary cutting, and the collecting bag collects all the falling thrombus in the thrombus taking process and the thrombus breaking process. The application can take out all the thrombus in the blood vessel at one time, is convenient to operate, and saves cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical devices, in particular to a cutting thrombectomy device. BACKGROUND

[0002] Thrombosis is the term for the formation of a blood clot within a blood vessel. A venous thrombosis is a blood clot (thrombus) that forms within a vein. A common type of venous thrombosis is deep venous thrombosis (DVT), which is a blood clot (thrombus) that forms in the deep veins of the leg. Non-specific signs can include pain, swelling, redness, heat and engorged superficial veins. If the thrombus breaks off (embolizes) and travels to the lungs, it can become a life-threatening pulmonary embolism (PE). In addition to the loss of life that can result from a PE, DVT can also cause significant health problems.

[0003] Interventional therapy (also known as interventional radiology) refers to a series of techniques that use puncture needles, catheters and other interventional devices to introduce specific instruments into the lesion site of the human body through natural orifices or small incisions for minimally invasive treatment under the guidance and monitoring of imaging equipment such as digital subtraction angiography machines, CT, ultrasound and magnetic resonance. The most commonly used method of interventional therapy is mechanical thrombectomy, intravenous thrombolysis and balloon dilation. Mechanical thrombectomy uses a guide catheter to establish a delivery channel and deliver a thrombectomy stent to the site of the thrombosis. After the thrombectomy stent is released, the thrombectomy stent cuts and withdraws the thrombus, and under the action of suction, the thrombectomy effect is achieved. Compared with traditional surgery, mechanical thrombectomy has the advantages of fast operation, suitability for acute patients, short preoperative preparation time and fast postoperative recovery. Some deep vein thrombosis is characterized by thick diameter and severe surface calcification, and there are also instruments on the market that are specifically designed for thrombectomy of large diameter blood vessels.

[0004] In today's world, endovascular interventional therapy has gradually become a trend in the treatment of intravascular diseases. In clinical practice, 10% to 20% of patients cannot achieve successful recanalization of the occluded blood vessels, among which intraoperative thrombus escape is the most common cause of incomplete recanalization of the blood vessels. In addition, the position of the thrombus is complex and the thrombus surface is calcified, which makes it difficult for the instrument to completely remove the thrombus at one time, and the instrument needs to be inserted into the patient's body multiple times to remove the residual thrombus, which prolongs the operation time and increases the risk of infection in patients.

[0005] Currently, there are thrombectomy systems available on the market for large vessels and large clots. These systems feature a large woven basket capable of collecting large clots throughout an entire vessel. However, these devices also have drawbacks. Besides the large volume of clots in large vessels, clots often have a hardened, calcified surface. This results in the clots often clumping together after being retrieved by the collection system, blocking the delivery / aspiration catheter and preventing retraction or removal. Increasing the withdrawal force can either damage the device, causing the stent and clot to become detached from the patient's vessel, a serious medical hazard. Alternatively, excessive withdrawal force can cause the stent to continuously exert pressure on the clot, squeezing the soft core of the clot, escaping through the stent mesh and being carried deeper into the bloodstream.

[0006] Therefore, those skilled in the art have devoted themselves to developing a cutting and thrombectomy device. Summary of the Invention

[0007] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to completely remove the thrombus at one time, thereby avoiding the need to insert the instrument into the patient's body multiple times to remove the residual thrombus.

[0008] To achieve the above-mentioned purpose, the present invention provides a cutting and thrombus removal device, which includes a delivery tube, an intermediate tube, an inner tube, a thrombus removal mechanism and a developing cap, wherein:

[0009] The intermediate tube is located at the proximal end of the device;

[0010] The developing cap is located at the distal end of the device and is provided with a developing function so that the thrombus removal mechanism can be clearly observed under imaging equipment;

[0011] The thrombus removal mechanism is located in the delivery tube, between the intermediate tube and the developing cap. The thrombus removal mechanism can be completely compressed in the delivery tube. The thrombus removal mechanism has a memory function and can freely contract and open to restore to its original state.

[0012] The thrombus removal mechanism includes a thrombus removal bracket, a cutting bag and a collecting bag. The thrombus removal bracket has a cutting wire with a rectangular cross-section, which can separate and pick the thrombus from the blood vessel wall; the cutting bag can collect large pieces of thrombus cut by the thrombus removal bracket and perform a second cutting; the collecting bag collects all the thrombi that fall during the thrombus removal process and the thrombus crushing process; the cutting bag and the collecting bag are opened and closed by control to achieve the cutting, separation and removal of the thrombus from the blood vessel wall.

[0013] Further, the thrombus collection stent is located at the most proximal position of the thrombus extraction mechanism, first contacts the thrombus and separates the thrombus from the blood vessel wall; the thrombus collection stent is provided with a large-diameter opening without other obstructions to hold and collect all the cut thrombus.

[0014] Further, the material of the thrombus collection stent is a memory alloy nickel-titanium, a nickel-titanium tube is used for laser cutting, and the tube is expanded into a mesh stent multiple times; the surface of the thrombus collection stent is subjected to sandblasting, pickling and oxidation treatment, and cutting burrs and sharp corners are removed.

[0015] Further, the thrombus collection stent adopts a double-layer nickel-titanium wire woven stent, and the diameter of the nickel-titanium wire can be flexibly adjusted according to different thrombus conditions.

[0016] Further, the cutting bag is provided with a large opening at the proximal end, the proximal end opening is fixedly connected with the distal end of the thrombus collection stent, the connection between the cutting bag and the thrombus collection stent has no any other intermediate transition, the distal end of the cutting bag is completely fixed with the inner tube, and the rotation of the inner tube can drive the distal end of the cutting bag to rotate, but the proximal end opening of the cutting bag does not rotate.

[0017] Further, the cutting bag comprises a nickel-titanium core shaft and a spring wire, the nickel-titanium core shaft is composed of a nickel-titanium wire, and the spring wire is wound on the surface of the nickel-titanium core shaft to weave a large-pitch mesh bag, the winding mode is non-tight winding, the friction force of the cutting bag with the contact surface of the thrombus is increased, the cutting bag can be freely opened and contracted, and a certain supporting force can be provided after being opened to support the entire mesh bag.

[0018] Further, the PPI of the cutting bag is 5-50, and the PPI value can be adjusted according to the size of the thrombus and different blood vessels.

[0019] Further, the material of the spring wire is stainless steel and / or high-density metal, and the high-density metal is platinum-tungsten alloy.

[0020] Further, the inner layer of the collection bag is a woven mesh woven by a nickel-titanium wire, an outer layer of the woven mesh is covered with a layer of high polymer material film, the proximal end opening of the woven layer of the collection bag is connected with the proximal end opening of the cutting bag at the distal end of the thrombus collection stent, and the distal end of the collection bag is sleeved by a distal end fixing ring, the distal end fixing ring is a hollow cylindrical structure and is sleeved on the inner tube, and the distal end fixing ring can move axially along the inner tube.

[0021] Further, the film material comprises polyurethane and polytetrafluoroethylene, the film thickness is 0.5mm-50mu, the film surface is distributed with innumerable film pores, and the film pores have a diameter of 0.5mm-30mu, facilitating blood passing.

[0022] In the preferred embodiment of the present application, compared with the prior art, the present application has the following technical effects:

[0023] 1. The cutting bag structure is added to the present application, so that the captured thrombus can be cut, and the present application is particularly suitable for large thrombus and calcified hard thrombus; the present application can take out all the thrombus in the blood vessel at one time, and residual thrombus can be completely taken out without multiple times of entering the blood vessel by using instruments, while the thrombus taking stent on the market is difficult to be taken out completely, and the thrombus taking risk is very high in this case.

[0024] 2. The cutting bag and the collecting bag of the present application can be controlled by the handle, so that the operation is convenient, medical materials are saved, and the consumption pressure of the patient is reduced.

[0025] The concept, specific structure and generated technical effects of the present application will be further described below with reference to the accompanying drawings, so as to fully understand the purpose, features and effects of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a cutting thrombus taking device set state schematic view of a preferred embodiment of the present application;

[0027] Figure 2 is a collecting bag not completely opened state schematic view of a preferred embodiment of the present application;

[0028] Figure 3 is a front view of a collecting bag completely opened state of a preferred embodiment of the present application;

[0029] Figure 4 is a side view of a collecting bag completely opened state of a preferred embodiment of the present application;

[0030] Figure 5 is a cutting wire spring winding mode schematic view of a cutting bag of a preferred embodiment of the present application;

[0031] Figure 6 is an enlarged view of a collecting bag of a preferred embodiment of the present application;

[0032] Figure 7 is a thrombus taking stent, collecting bag and cutting bag connection mode schematic view of a preferred embodiment of the present application;

[0033] Figure 8 is a handle schematic view of a preferred embodiment of the present application;

[0034] Figure 9 This is a schematic diagram of a preferred embodiment of the present invention showing a cutting and thrombectomy device reaching a lesion site and a developing cap passing through a thrombus;

[0035] Figure 10 is a schematic diagram of a thrombus removal mechanism according to a preferred embodiment of the present invention after being released from a delivery tube;

[0036] Figure 11 This is a schematic diagram of a preferred embodiment of the present invention for scraping a large thrombus off a blood vessel wall and transporting it to a cutting bag;

[0037] Figure 12 This is a schematic diagram of a preferred embodiment of the present invention showing a whole thrombus being cut into multiple small fragments;

[0038] Figure 13 1. A top view of the arrangement of a bare nickel-titanium mandrel and a surface-wound spring mandrel in accordance with a preferred embodiment of the present invention;

[0039] Figure 14 This is a schematic diagram of another connection and fixing method between the cutting bag and the inner tube in a preferred embodiment of the present invention.

[0040] Among them: 1-delivery tube, 2-middle tube, 3-inner tube, 4-thrombus removal mechanism, 5-developing cap, 6-thrombus removal bracket, 7-cutting bag, 8-collecting bag, 9-spring wire, 10-nickel-titanium core shaft, 11-proximal fixing ring, 12-distal fixing ring, 13-thin film, 14-membrane pore, 15-braided mesh, 16-handle, 17-movable knob, 18-locking button, 19-thrombus, 20-blood vessel, 21-guidewire, 22-small broken thrombus. DETAILED DESCRIPTION

[0041] The following describes several preferred embodiments of the present invention with reference to the accompanying drawings to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0042] In the drawings, components with identical structures are denoted by the same reference numerals, and components with similar structures or functions are denoted by similar reference numerals. The size and thickness of each component shown in the drawings are arbitrary and are not limited by the present invention. For clarity, the thickness of components in some places in the drawings is appropriately exaggerated.

[0043] like Figure 1As shown, the cutting and thrombus taking device provided by the embodiment of the application comprises a delivery tube 1, an intermediate tube 2, an inner tube 3, a thrombus taking mechanism 4 and a developing cap 5. The intermediate tube 2 is located at the proximal end of the device, and the developing cap 5 is located at the distal end of the device. The developing cap 5 is provided with a developing function, so that the thrombus taking mechanism 4 can be clearly observed under the imaging equipment. The proximal end of a general instrument refers to the end of the instrument held by the doctor, and the distal end refers to the end of the instrument away from the doctor. The developing cap is away from the doctor in the patient's body, so it is the distal end. The thrombus taking mechanism 4 is located in the delivery tube 1, between the intermediate tube 2 and the developing cap 5. The thrombus taking mechanism 4 can be completely compressed in the delivery tube 1. The thrombus taking mechanism 4 has a memory function and can freely contract and open to recover to the original state.

[0044] As shown in the figure, Figures 2-4 The thrombus taking mechanism 4 comprises a thrombus taking stent 6, a cutting bag 7 and a collecting bag 8. The thrombus taking stent 6 is located at the proximal end of the thrombus taking mechanism 4 and first contacts the thrombus 19. The thrombus taking stent 6 has a cutting wire with a rectangular cross section. The burrs are removed after special treatment of the corners, so that the thrombus taking stent 6 can cut into the thrombus 19 without scratching the blood vessel 20. The thrombus taking stent 6 can separate and pick up the thrombus 19 from the blood vessel wall. The thrombus taking stent 6 is provided with a large-diameter opening. The large-diameter opening is not blocked and can hold and collect all the cut thrombus 19. The material of the thrombus taking stent 6 is a memory alloy of nickel-titanium. A nickel-titanium tube is used for laser cutting, and the tube is expanded into a mesh stent multiple times. The surface of the thrombus taking stent 6 is sandblasted, pickled and oxidized, and the cutting burrs and sharp corners are removed. The rounded edges will not damage the blood vessel. The thrombus taking stent 6 uses a double-layer nickel-titanium wire woven stent. The diameter of the nickel-titanium wire can be adjusted flexibly according to different thrombus conditions.

[0045] The cutting bag 7 is provided with a large opening at the proximal end. The proximal end opening is fixedly connected to the distal end of the thrombus taking stent 6. The connection between the cutting bag 7 and the thrombus taking stent 6 has no other intermediate transition. The distal end of the cutting bag 7 is completely fixed to the inner tube 3. The inner tube 3 can rotate to drive the distal end of the cutting bag 7 to rotate, but the proximal end opening of the cutting bag 7 does not rotate. The cutting bag 7 can collect the large thrombus cut by the thrombus taking stent 6 and perform secondary cutting. The collecting bag 8 collects all the falling thrombus 19 during the thrombus taking process and the thrombus breaking process. The cutting bag 7 and the collecting bag 8 are opened and closed by control, so as to cut and separate the thrombus 19 from the blood vessel wall and take out the thrombus 19.

[0046] As shown in the figure, Figures 5-7As shown, the cutting bag 7 includes a nickel-titanium core shaft 10 and a spring wire 9, the nickel-titanium core shaft 10 is composed of a nickel-titanium wire, and the spring wire 9 is wound on the surface of the nickel-titanium core shaft 10 and woven into a large-pitch mesh bag, the winding mode is non-tight winding, which increases the friction force of the contact surface of the cutting bag 7 and the thrombus 19, and the cutting bag 7 can be freely opened and contracted, and can provide a certain supporting force after being opened, and support the entire mesh bag. The PPI of the cutting bag 7 is 5-50, which can be adjusted according to the size of the thrombus 19 and different blood vessels. The material of the spring wire 9 is stainless steel and / or high-density metal, and the high-density metal is platinum-tungsten alloy.

[0047] The collection bag 8 is divided into an inner layer and an outer layer, the inner layer is a woven mesh 15 woven by a nickel-titanium wire, and the outer layer of the woven mesh is covered with a layer of high polymer material film 13, the material of the film 13 includes polyurethane and polytetrafluoroethylene, the thickness of the film 13 is 0.5mm-50μm, and a large number of film pores 14 are distributed on the surface of the film 13, the diameter of the film pores 14 is 0.5mm-30μm, facilitating the blood to pass through. The proximal opening of the woven layer of the collection bag 8 is connected with the proximal opening of the cutting bag 7 at the distal end of the thrombus stent 6, and the distal end of the collection bag 8 is sleeved by the distal end fixing ring 12, the distal end fixing ring 12 is a hollow cylindrical structure and is sleeved on the inner tube 3, and the distal end fixing ring 12 can move axially along the inner tube 3.

[0048] As Figures 8-9As shown, the distal end of the handle 16 of the cutting thrombectomy device is connected to the outer tube 1 and is fixed, and there is a movable knob 17 in the middle that can control the rotation and axial movement of the inner tube 3, thereby controlling the opening and closing of the thrombectomy mechanism 4 and the cutting action. There is a locking button 18 on the handle, which can lock the movable knob 17 at any position, making it convenient for doctors to operate. The rotation of the inner tube 3 is controlled by the movable knob 17 connected to the proximal end of the inner tube on the handle 16. The proximal end of the inner tube 3 is fixed with the inner hole of the movable knob 17. The movable knob 17 can rotate by itself and drive the inner tube 3 to rotate, thereby driving the cutting bag 7 to rotate from bottom to top. In addition to being able to rotate, the movable knob 17 can also move axially along the handle, thereby driving the inner tube 3 to move forward and backward. The inner tube 3 has a proximal end fixed ring 11. When the movable knob 17 slides from the proximal end point to the distal end point of the guide groove of the handle 16, the inner tube extends and the proximal end fixed ring 11 extends axially, contacts the distal end fixed ring 12, and drives the distal end fixed ring 12 to continue to extend until the movable knob 17 reaches the distal end point. At this time, the collection bag 8 and the cutting bag 7 are completely straightened and the diameter is reduced. During this process, the diameter of the thrombectomy mechanism 4 is flexible and adjustable, which is convenient for recycling or passing through some relatively narrow sections of blood vessels. When the movable knob 17 moves from the distal end to the proximal end of the handle guide groove, the movable knob 17 drives the inner tube 3 to be recovered and shortened. At this time, the distal end of the development cap 5 drives the fixed ring 12, thereby continuing to drive the collection bag to move towards the proximal end, gradually opening the collection bag. At this time, as the inner tube 3 is recovered towards the proximal end, the cutting bag 11 fixed at the distal end of the inner tube 3 is also gradually opened from the distal end to the proximal end like the collection bag. Until the movable knob 17 moves to the proximal end fixed point of the handle guide groove, at this time the collection bag 8 and the cutting bag 7 are completely opened.

[0049] The cutting thrombus extraction device provided by the embodiment of the present application is combined with the self-expanding cutting stent and the braided stent structure by improving the thrombus extraction stent, the opening and closing of the thrombus extraction stent system and the cutting of the thrombus are adjusted freely through the handle. The proximal thrombus extraction stent first contacts the thrombus, and can be designed into a large opening according to different blood vessels, which is beneficial to peeling the thrombus closely adhered to the blood vessel wall, and the peeled thrombus is sent into the cutting capsule bag connected with the thrombus extraction stent. The capsule bag is woven from a high-elasticity memory alloy material nickel-titanium wire, and a spring with a spacing pitch is wound on the surface of the nickel-titanium wire. The spring is composed of a high-density metal alloy, which can not only enhance the friction force when the thrombus is adhered, but also enable the entire cutting capsule bag to have a developing function. During the operation, the cutting capsule bag in the body can be clearly observed by the doctor under the imaging equipment, so that the thrombus cutting shape change can be concerned at any time. The distal end of the capsule bag is fixed together with the inner tube. The inner tube and the cutting capsule bag are rotated by rotating the operating knob of the handle, the capsule bag is wrapped around the thrombus, and the sharp nickel-titanium wire mesh will cut the large thrombus into countless small fragments. The small fragments will be caught by the collection bag. Because the proximal end of the collection bag is also connected with the distal end of the thrombus extraction stent and the proximal end of the cutting capsule bag, the collection bag can directly hold all the fragments falling from the cutting capsule bag and the thrombus extraction stent. The inner layer of the collection bag is a mesh woven from a nickel-titanium wire, which can provide a certain supporting force. The inner tube is moved forward and backward by moving the operating knob of the handle forward and backward, so as to control the opening and closing of the woven mesh of the collection bag. The outer layer of the woven mesh is covered with a layer of high-molecular material film, and the film has a large number of small openings, which facilitates the blood flow, but does not allow the thrombus larger than 1 mm to pass through. This design can not only ensure that all the fragments are collected by the collection bag, but also does not affect the normal blood flow during the operation, and the operation will not bring a large amount of blood to cause ischemia in the patient. The inner layer is woven and the outer layer is covered with a high-molecular material film, and this structure design enables the entire collection bag to pass through the blood vessels with different bending degrees and different diameter changes. The smooth outer wall of the high-molecular material also greatly reduces the damage to the inner wall of the blood vessel during the retraction of the collection bag in the blood vessel. For the large thrombus in the deep vein, this instrument can directly and completely extract all the thrombus at one time, without repeatedly entering the instrument to extract the thrombus, greatly shortening the operation time and reducing the pain of the patient.

[0050] The preferred embodiment of the present application will be described in detail below in combination with the drawings and the preferred embodiment of the present application:

[0051] Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 The structure diagram of the cutting thrombus extraction device. The cutting thrombus extraction device is composed of a delivery tube 1, an intermediate tube 2, an inner tube 3, a thrombus extraction mechanism 4 and a developing cap 5.

[0052] Figure 1is a schematic diagram of the cutting thrombus extraction device in the unused, packaged state, wherein the thrombus extraction mechanism 4 can be fully compressed within the delivery tube 1. The thrombus extraction mechanism 4 has strong memory and can freely shrink and open to restore to its original shape. The thrombus extraction mechanism 4 is composed of a thrombus extraction stent 6, a cutting bag 7, and a collection bag 8. The thrombus extraction stent 6 has strong radial support and is located at the most proximal end of the entire thrombus extraction structure, first contacting the thrombus 19 and bearing the function of separating the thrombus 19 from the blood vessel wall. Therefore, the structure is not easily deformed by the thrombus 19. When encountering some calcified and adhered thrombus 19 on the blood vessel wall, the thrombus extraction stent 6 can remove the thrombus 19 from the blood vessel wall due to its own structure and material characteristics. The large-diameter opening is not blocked and has good blood vessel 20 adhesion performance, ensuring that all thrombus 19 can be caught by the thrombus extraction stent 6 during the entire thrombus extraction process, and no thrombus 19 will escape from the gap between the thrombus extraction stent 6 and the blood vessel wall. The material of the thrombus extraction stent 6 is a memory alloy of nickel-titanium, which is cut by laser and expanded into a mesh stent multiple times, which is the best solution. Because the cutting shape has a rectangular cutting section, it can well separate and pick up the thrombus 19 from the blood vessel wall. The surface of the thrombus extraction stent 6 is sandblasted, pickled, and oxidized to remove cutting burrs and sharp corners, and the rounded edges will not damage the blood vessel. The thick outer wall and closed loop stent structure can ensure that the thrombus extraction stent 6 has strong radial support and anti-deformation capabilities, ensuring that the thrombus extraction stent 6 will not be deformed by the thrombus during the thrombus extraction process. The thrombus extraction stent 6 has strong memory characteristics and multiple expansion heat treatment processes, so it has good self-expanding performance and can be freely shrunk into the delivery tube and released at any time, and can also be smoothly self-expanded and fully opened. In another alternative solution, for some weak or soft thrombus blood vessels, the thrombus extraction stent 6 can be replaced with a double-layer nickel-titanium wire woven stent, which can be adjusted according to different thrombus conditions.

[0053] The cutting bag 7 can collect and cut the large thrombus 19 cut by the thrombus extraction stent 6. Especially for some large thrombus with calcified surface, the surface texture is hard, and it is difficult for the thrombus extraction system on the market to take it out as a whole. However, the unique cutting bag 7 of the cutting thrombus extraction device of the present application can solve this problem well. Figure 5, the cutting bag 7 is composed of a nickel-titanium core shaft 10 and a spring wire 9. The nickel-titanium core shaft 10 uses a nickel-titanium wire, and the surface is wound with a stainless steel spring wire 9 to form a large-pitch mesh bag. After heat treatment process, the whole mesh bag has good material memory, can be freely opened and contracted, and can provide certain supporting force after opening to support the whole mesh bag. The spring wire 9 is wound on the surface of the nickel-titanium core shaft 10, and the winding mode is non-tight winding. This structure can increase the friction force of the contact surface between the cutting bag 7 and the thrombus 19. Part of the spring wire 9 material can also be replaced with high-density metal, such as platinum-tungsten alloy, etc., so that the whole cutting bag 7 has a developing function. During the operation, the cutting bag 7 in the body can be clearly observed by the doctor under the imaging equipment, so as to pay attention to the thrombus cutting shape change at any time. In order to have better cutting effect, the whole cutting bag 7 does not need to be wound with a spring on the nickel-titanium core shaft 10, because the smooth nickel-titanium core shaft has smaller contact surface area with the thrombus, and is relatively more sharp and easier to cut the thrombus. For example Figure 13 The figure is a top view of the arrangement mode of the bare nickel-titanium core shaft and the core shaft wound with a spring. The wavy line is the nickel-titanium wire wound with a spring, and the straight line is the bare nickel-titanium wire. The weaving PPI of the cutting bag 7 is 5-50, which can be adjusted according to the thrombus and different blood vessels. The larger the mesh, the more suitable for cutting large thrombus.

[0054] For example Figure 3 And Figure 4 The large opening of the proximal end of the cutting bag 7 is connected with the distal end of the thrombus extraction stent 6, and the connection mode is as shown in Figure 7 The connection mode makes the connection between the cutting bag 7 and the thrombus extraction stent 6 without any other intermediate transition, which can not only ensure the connection reliability, but also ensure that the thrombus 19 extracted from the thrombus extraction stent 6 directly enters the cutting bag 7 for thrombus cutting. The distal end of the cutting bag 7 is completely fixed with the inner tube 3. The rotation of the inner tube 3 can drive the cutting bag to rotate. However, the proximal end of the cutting bag 7 is fixedly connected with the thrombus extraction stent 6 and will not rotate. With the continuous rotation of the inner tube, the torsional force on the whole cutting bag 7 continuously increases, and finally the cutting bag itself is twisted and the diameter of the cutting bag itself is continuously reduced. At this time, the thrombus 19 is wrapped in the bag, and the wrapping force around the thrombus 19 becomes larger and larger. At the same time, the spring wire 9 on the cutting core shaft increases the friction force with the thrombus 19 in the axial position, preventing the thrombus 19 from being squeezed to the opening of the cutting bag 7. When the rotating wrapping force reaches a certain value, the cutting mesh on the surface of the cutting bag 7 is completely embedded into the thrombus 19, cutting the thrombus 19 into countless small pieces 22, and the falling pieces will fall into the collection bag 8 from the cutting mesh hole of the cutting bag 7.

[0055] The rotation of the inner tube 3 is controlled by the movable knob 17 on the handle 16 connected with the proximal end of the inner tube. For example Figure 8, the inner tube 3 is fixed with the inner hole of the movable knob 17. The movable knob can rotate and drive the inner tube 3 to rotate, thus driving the cutting bag 7 to rotate spirally from bottom to top. The movable knob 17 can move forward and backward along the handle in axial direction, thus driving the inner tube 3 to move forward and backward. The inner tube 3 has a proximal end fixed ring 11, when the movable knob 17 slides from the proximal end point to the distal end point of the guide groove of the handle 16, the inner tube extends and the proximal end fixed ring 11 extends in axial direction, contacts the distal end fixed ring 12, and drives the distal end fixed ring 12 to continue to extend until the movable knob 17 reaches the distal end point completely. At this time, the collection bag 8 and the cutting bag 7 are completely straightened and the diameter is reduced, as shown in Figure 2 . The diameter of the stent-retrieving mechanism 4 is flexible and adjustable during the process, which is convenient for recycling or passing through some relatively narrow blood vessels. When the movable knob 17 moves from the distal end to the proximal end of the handle guide groove, the movable knob 17 drives the inner tube 3 to be recycled and shortened, at this time the distal end developing cap 5 drives the fixed ring 12, thus continuing to drive the collection bag to move to the proximal end, and gradually opening the collection bag. At this time, with the inner tube 3 being recycled to the proximal end, the cutting bag 11 fixed at the distal end of the inner tube 3 is also gradually opened from the distal end to the proximal end like the collection bag. Until the movable knob 17 moves to the proximal end fixed point of the handle guide groove completely, at this time the collection bag 8 and the cutting bag 7 are completely opened, as shown in Figure 3 .

[0056] As shown in Figure 8 , the handle 16 of the cutting stent-retrieving device is connected with the outer tube 1 and fixed, and the movable knob 17 can control the rotation and axial forward and backward movement of the inner tube, thus controlling the opening and closing of the stent-retrieving mechanism 4 and the cutting action. The handle has a locking button 18, which is convenient for locking the movable knob 17 at any position, and is convenient for the doctor to operate.

[0057] As shown in Figure 4 , it is a side view of the collection bag 8 in the completely opened state, Figure 3 , it is a front view of the collection bag 8 in the completely opened state. The distal end of the collection bag 8 is not fixed with the inner tube 3, but is sleeved through the distal end fixed ring 12. The distal end fixed ring 12 is fixed on the distal end of the collection bag 8 and is a hollow cylindrical structure sleeved on the inner tube 3. It can move in axial direction along the inner tube 3. This mechanism can ensure that the rotation of the inner tube 3 will not drive the collection bag 8 to rotate. However, the axial forward and backward movement of the inner tube 3 can drive the collection bag 8 to open and close through the developing cap 5.

[0058] As shown in Figure 6is a magnified view of the collection bag 8, the inner layer of the collection bag 8 is a braided mesh 15 woven by nickel-titanium wire, which can provide a certain supporting force. And the memory alloy material enables the collection bag 8 to maintain good shape ability during the contraction and opening process, so that the collection bag 8 does not collapse when completely opened to take out the thrombus. The outer layer of the braided mesh 15 is covered with a layer of high polymer material film 13, which can be but is not limited to polyurethane and polytetrafluoroethylene, and the thickness of the film 13 is recommended to be 0.5mm-50μm. The surface of the film is distributed with a large number of film pores 14, and the diameter of the film pores 14 can be 0.5mm-30μm. These holes can allow blood to flow freely, but can block thrombi with a diameter of more than 1mm, and the thrombi with a diameter of less than 1mm flowing into the blood vessel will not cause other serious reactions to the human body. The proximal opening of the braided layer of the collection bag 8 is connected with the proximal opening of the cutting balloon bag 7 at the distal end of the thrombus taking stent 6, and the connection structure is the same as that of the cutting balloon bag 7, as shown in Figure 7 This structure can ensure that all the thrombi 19 falling during the thrombus taking process and the thrombus breaking process can be caught by the collection bag 8, and the thrombus escape problem is well solved. During the retraction of the cutting thrombus taking device, the blood flow normally flows away from the film pores 14, which does not affect the blood flow direction of the patient himself, and a large amount of blood is not taken out when the thrombus is taken out, reducing the amount of bleeding of the patient. The inner layer of the collection bag 8 is covered with a high polymer film on the outer layer of the nickel-titanium wire, which makes the collection bag have good supporting ability, keep completely open during the thrombus taking process, and make the whole thrombus taking mechanism have good blood vessel adaptability, which can pass through blood vessels with different bending degrees and different diameter changes. The smooth surface of the high polymer film is in close contact with the blood vessel, which reduces the friction to the minimum during the retraction movement, greatly reduces the damage to the inner wall of the blood vessel, and reduces the pain of the patient. The collection bag 8 is flexibly controlled by the handle to realize opening and contraction, which is convenient for the doctor to flexibly adjust during the operation process and improves the success rate of the operation.

[0059] As shown in Figure 14 Another preferred embodiment of the connection and fixing mode of the cutting balloon bag 7 and the inner tube 3 provided in the embodiment of the application is that the outer layer of the cutting balloon bag 7 is wrapped around the inner tube 3. This structure provides a large rotating wrapping force for the cutting balloon bag 7, and the effect of cutting some thrombi with hard surfaces will be very good.

[0060] In addition, for some blood vessels with very large diameters and large thrombi, the outer layer of the collection bag 8 can also be made of a double-layer high-density nickel-titanium wire braided structure. The collection bag 8 made of the double-layer braided mesh has strong radial supporting force and can uniformly support the blood vessel wall without collapse, and the high-density mesh can also effectively filter the broken thrombus.

[0061] The cutting thrombus taking device provided in the embodiment of the application has the following advantages:

[0062] 1. The addition of a cutting pocket 7 allows for the excision of captured thrombi 19. This is particularly useful for large and calcified hard thrombi, which are difficult to completely remove with current thrombectomy stents and are associated with a high risk of thrombectomy. The present invention allows for the complete removal of intravascular thrombi in one go, eliminating the need for multiple insertions to completely remove residual thrombi.

[0063] 2. The cutting bag 7 and the collecting bag 8 are controlled by the handle 16, which increases the adjustable functions. However, the operation of the instrument by the doctor does not become complicated, and other operating instruments and operating procedures such as balloon dilation are not required. This is convenient for the doctor to operate, saves medical materials, and reduces the consumption pressure of patients.

[0064] 3. The spring wire 9 on the cutting bag 7 not only enhances the system's visualization effect, but also increases the friction between the cutting bag 7 and the thrombus 19, improving the efficiency of thrombus cutting. The spring structure also increases the softness and compliance of the cutting bag 7, improving its flexibility.

[0065] 4. The collection bag 8 completely conforms to the vessel wall, collecting any thrombi 19 that are released during thrombectomy and fragmentation, eliminating the risk of thrombi 19 escaping. The inner woven structure ensures the collection bag has excellent support and conforms evenly to the vessel wall. The outer perforated membrane structure prevents even small thrombi from escaping through the pores of the collection bag 8, allowing blood to flow freely through the pores. This does not affect the patient's normal blood flow during surgery, and also reduces blood drawn from the vessel by the instrument, minimizing intraoperative bleeding.

[0066] 5. The friction between the outer polymer coating material and the blood vessel wall is much smaller than that of a bare thrombectomy stent, which greatly reduces the damage of the device to the blood vessel wall.

[0067] like Figure 1 、 Figures 9-12 As shown, the specific method of using the cutting and thrombus removal device provided in the embodiment of the present invention is as follows:

[0068] Step 1: With the thrombectomy device in place, insert the delivery tube 1 along the guide wire 21 through the puncture port into the blood vessel 20. After reaching the lesion site, the developing cap passes through the thrombus 19 for a distance.

[0069] Step 2: After the delivery tube 1 is released to the appropriate position, the delivery tube 1 is withdrawn to release the thrombus removal mechanism 4 from the delivery tube 1;

[0070] Step 3: Slowly push the movable knob 17 on the handle 16 from the distal end of the handle slot to the proximal end, and press the locking button 18. At this time, the collecting bag 8 and the cutting bag 7 are fully opened;

[0071] Step 4: The delivery tube 1 is retracted, and the whole thrombus extraction mechanism is retracted at the same time. The thrombus extraction support 6 scrapes the large thrombus 19 from the blood vessel wall and delivers it into the cutting bag 7.

[0072] Step 5: The knob 17 on the handle 16 is rotated, and the inner tube 3 is rotated by the knob 17. The inner tube 3 rotates the cutting bag 7 to spiral around the thrombus 19. As the number of rotations of the knob 17 increases, the spiral force of the cutting bag 7 continues to increase, and the whole thrombus 19 is cut into small pieces 22 by the nickel-titanium core shaft 10 and falls into the collection bag 8 from the mesh of the cutting bag 7.

[0073] Step 6: As the delivery tube 1 continues to retract, the collection bag 8 continues to filter the thrombus pieces in the blood until all the thrombus 19 is extracted out of the body.

[0074] The preferred embodiments of the present application are described in detail above. It should be understood that those of ordinary skill in the art can make modifications and variations to the present application without creative work based on the concept of the present application. Therefore, any technical solutions obtained by logical analysis, reasoning or limited experiments based on the prior art within the concept of the present application should be within the protection scope determined by the claims.

Claims

1. A cutting and thrombus removal device, characterized in that: The device includes a delivery tube, an intermediate tube, an inner tube, a thrombus removal mechanism and a developing cap, wherein: The intermediate tube is located at the proximal end of the device; The developing cap is located at the distal end of the device and is provided with a developing function so that the thrombus removal mechanism can be clearly observed under imaging equipment; The thrombus removal mechanism is located in the delivery tube, between the intermediate tube and the developing cap. The thrombus removal mechanism can be completely compressed in the delivery tube. The thrombus removal mechanism has a memory function and can freely contract and open to restore to its original state. The thrombus removal mechanism includes a thrombus removal stent, a cutting pouch, and a collection bag. The thrombus removal stent has a cutting wire with a rectangular cross-section, which can separate and remove thrombi from the blood vessel wall; the cutting pouch can collect large pieces of thrombi cut by the thrombus removal stent and perform secondary cutting; the collection bag collects all thrombi that fall during the thrombus removal and thrombus fragmentation process; the cutting pouch and the collection bag are opened and closed by control to separate and remove the thrombi from the blood vessel wall. in, The thrombus collection bracket is located at the most proximal end of the thrombus removal mechanism. The thrombus collection bracket is provided with a large-caliber opening. The large-caliber opening is free of other obstructions and can capture and collect all the cut thrombi. The proximal end of the cutting bag is provided with a large opening, which is fixedly connected to the distal end of the embolism extraction bracket. The connection between the cutting bag and the embolism extraction bracket does not have any other intermediate transitions. The distal end of the cutting bag is completely fixed to the inner tube. The rotation of the inner tube can drive the distal end of the cutting bag to rotate, but the proximal large opening of the cutting bag does not rotate. The proximal opening of the collecting bag and the large proximal opening of the cutting bag are connected to the distal end of the thrombus collection bracket. The distal end of the collecting bag is sleeved on the inner tube through a distal fixing ring. The collecting bag does not rotate with the inner tube. The front and rear axial movement of the inner tube drives the collecting bag to open and close through the developing cap.

2. The device according to claim 1, wherein The thrombus removal stent first contacts the thrombus and separates the thrombus from the blood vessel wall.

3. The device according to claim 2, wherein The material of the thrombus removal bracket is the memory alloy nickel-titanium, which is laser cut using a nickel-titanium tube and expanded multiple times into a mesh bracket; the surface of the thrombus removal bracket is sandblasted, pickled and oxidized, and cutting burrs and sharp corners are removed.

4. The device according to claim 2, wherein The thrombus removal stent is a double-layer nickel-titanium wire braided stent, and the diameter of the nickel-titanium wire can be flexibly adjusted according to different thrombosis conditions.

5. The device according to claim 4, characterized in that The cutting bag includes a nickel-titanium core shaft and a spring wire. The nickel-titanium core shaft is composed of nickel-titanium wire. The spring wire is wound on the surface of the nickel-titanium core shaft and woven into a large-pitch net bag. The winding method is non-tight winding, which increases the friction between the contact surface between the cutting bag and the thrombus. The cutting bag can be opened and contracted freely, and can provide a certain supporting force after opening to support the entire net bag.

6. The device according to claim 5, characterized in that The PPI of the cutting bag weaving is 5-50, and the PPI value can be adjusted according to the size of the thrombus and different blood vessels.

7. The device according to claim 6, characterized in that The material of the spring wire is stainless steel and / or high-density metal, and the high-density metal is platinum-tungsten alloy.

8. The device according to claim 7, wherein The inner layer of the collection bag is a woven mesh woven from nickel-titanium wire, and the outer layer of the woven mesh is covered with a layer of polymer material film. The proximal opening of the woven layer of the collection bag and the large proximal opening of the cutting bag are connected to the distal end of the thrombus collection bracket. The distal fixing ring is a hollow cylindrical structure and is sleeved on the inner tube. The distal fixing ring can move axially along the inner tube.

9. The device according to claim 8, wherein The film material includes polyurethane and polytetrafluoroethylene, the film thickness is 0.5mm~50μm, and numerous membrane pores are distributed on the surface of the film. The diameter of the membrane pores is 0.5mm~30μm, which facilitates blood passage.

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