Sheath tube assembly and thrombectomy device

Abstract

The invention provides a sheathing canal assembly and a thrombectomy device. The sheathing canal assembly comprises a sheathing canal connector, a sheathing canal of a tubular structure and a flared tube. The sheath tube is arranged outside the flared tube in a sleeving mode, and the near end of the sheath tube is connected with the sheath tube connector. The flared tube extends along the axial direction of the sheathing canal and can axially move relative to the sheathing canal; a flaring part is arranged at the far end of the flaring tube, the flaring part can axially move relative to the sheath tube along with the flaring tube, when the whole flaring part is located in the sheath tube, the flaring part is in a contraction state, and when at least part of the flaring part is located outside the sheath tube, the flaring part is in an expansion state. The sheath tube assembly of the thrombus extraction device is provided with the telescopic adjustable flaring part, thrombus in blood vessels of different specifications can be completely taken out or dragged into the flaring sheath without omission, further, the sheath tube assembly is combined with a single-cavity microfilament balloon catheter with good pushing performance, the assembly is simple in structure, surgical operation is convenient, and the thrombus extraction device is suitable for large-scale popularization and application. Thrombus can be rapidly taken out, and damage to the blood vessel wall is reduced as much as possible.

Description

Technical Field

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

[0002] Thrombus is a small piece of blood formed on the surface of the peeling or repaired part of the inner surface of the cardiovascular system. It is composed of insoluble fibrin, deposited platelets, accumulated white blood cells and trapped red blood cells. It can occur in any part of the blood circulation, and once it breaks off, there is a risk of embolism. According to the anatomical location of the thrombus in the body, the size of the thrombus and the components it contains, it can be divided into three types: venous thrombosis, arterial thrombosis and mixed thrombosis.

[0003] There are several ways to treat thromboembolism:

[0004] Method 1: Oral antithrombotic drugs. This method is generally used for prevention and treatment, but it often fails to achieve the purpose of effective treatment.

[0005] Method 2: Drug thrombolysis, which directly delivers drugs to the thrombus to dissolve it. This method is called contact thrombolysis. In this method, due to the large dose of thrombolytic drugs and the high risk of bleeding, the method of thrombolysis needs to be selected according to the condition. Therefore, many patients cannot be treated with this method.

[0006] Method three: interventional surgery, such as the use of a suction catheter to perform thrombus aspiration for treatment. Regardless of whether it is manual or mechanical aspiration, this type of product is expensive, complicated to operate, and takes a long time to operate. It only has good treatment results for large thrombi in large-diameter blood vessels, and there are residual thrombi. Filters need to be implanted to prevent the remaining small thrombi from entering the blood circulation system and forming acute emboli elsewhere; or the thrombus can be retrieved by physically dragging it with a thrombectomy stent or balloon.

[0007] The existing patent discloses a double-lumen thrombectomy catheter, which can perform dual functions of drug thrombolysis and balloon thrombectomy through the double-lumen structure, but cannot solve the problem of thrombus detachment and overflow during use. At the same time, the double-lumen catheter has a multi-layer structure, a large size, and poor permeability. It cannot penetrate longer and more complex thrombi for thrombectomy, and has certain limitations.

[0008] Therefore, in view of the shortcomings of the existing technology, there is a need to provide an interventional thrombectomy device with good permeability, a wide range of applications, the ability to better collect and contain thrombi, and easy use. Summary of the invention

[0009] In view of the problems in the prior art, the purpose of the present invention is to provide a sheath assembly and a thrombus removal device. The sheath assembly has a retractable and adjustable flared portion, which can completely and without omission drag the thrombus in blood vessels of different specifications into the flared portion, and then remove it through the sheath. Furthermore, the above-mentioned sheath assembly is combined with a microfilament balloon catheter with good pushing performance to form a thrombus removal device. The whole set of components has a simple structure and convenient surgical operation. It can quickly remove the thrombus and minimize the damage to the blood vessel wall.

[0010] A first aspect of the present invention provides a sheath tube assembly, comprising a sheath tube joint, a sheath tube of a tubular structure, and a flared tube;

[0011] The sheath tube is sleeved on the outside of the flared tube, and the proximal end of the sheath tube is connected to the sheath tube connector;

[0012] The flared tube extends along the axial direction of the sheath tube and is axially movable relative to the sheath tube;

[0013] The distal end of the flared tube is provided with a flared portion, which can move axially with the flared tube relative to the sheath tube. When the flared portion is entirely within the sheath tube, it is in a contracted state, and when at least part of the flared portion is outside the sheath tube, it is in an extended state.

[0014] According to the first aspect of the present invention, the sheath tube assembly further comprises a flaring cap connected to the proximal end of the flaring tube, and rotation of the flaring cap drives the flaring tube to move axially relative to the sheath tube.

[0015] According to the first aspect of the present invention, the sheath assembly further comprises a positioning member detachably connected to the sheath connector, wherein the positioning member abuts against the distal end of the flaring cap to limit the rotation of the flaring cap toward the distal end.

[0016] According to the first aspect of the present invention, the cross section of the flared portion in the extended state is trumpet-shaped.

[0017] According to the first aspect of the present invention, when the flared portion is in the contracted state or the extended state, a radial dimension of the flared portion ranges from 2 mm to 12 mm.

[0018] According to the first aspect of the present invention, the flared portion is made by a heat setting or cold setting process; the material of the flared portion is a polymer material.

[0019] According to the first aspect of the present invention, the sheath tube includes an inner layer, an outer layer, and a braided layer between the inner layer and the outer layer.

[0020] According to the first aspect of the present invention, the braided layer is braided from silk materials, and the braiding density of the proximal end of the braided layer is greater than that of the distal end thereof; the inner layer and / or the outer layer is a polymer tube.

[0021] The second aspect of the present invention provides a thrombus removal device, comprising the sheath tube assembly and a balloon catheter, wherein the flared tube has a channel for the balloon catheter to pass through, and the balloon catheter comprises a microwire, a balloon and a catheter seat;

[0022] The proximal end of the microwire is connected to the catheter seat, and the balloon sleeve is arranged on the distal end of the microwire;

[0023] The microwire is provided with a hollow cavity and a side hole, and the cavity is connected with the balloon through the side hole.

[0024] According to the second aspect of the present invention, the radial dimension of the microwire is between 0.4 mm and 1.0 mm.

[0025] According to the second aspect of the present invention, the microwire is a single-layer structure; or,

[0026] The microfilament has a double-layer structure, and the microfilament comprises a polyimide inner layer and a segmented polyetheramide resin outer layer, or the microfilament comprises a polyimide inner layer and a polyamide outer layer; or,

[0027] The microfilaments are of a three-layer structure, comprising a high-density polyethylene inner layer, a linear low-density polyethylene middle layer and a segmented polyetheramide resin outer layer;

[0028] Alternatively, the microwire has a structure of four or more layers.

[0029] According to the second aspect of the present invention, the balloon catheter further comprises a reinforcing tube, and the proximal end of the microwire is connected to the catheter seat via the reinforcing tube.

[0030] According to a second aspect of the present invention, the balloon catheter further comprises a tip portion connected to the distal end of the microwire, and an outer diameter of the tip portion gradually decreases in an axial direction from the proximal end to the distal end.

[0031] According to a second aspect of the present invention, the balloon catheter further comprises a developing member, and the developing member is disposed at the proximal end of the balloon or the distal end of the balloon.

[0032] The distal end of the flared tube of the sheath assembly of the present invention is provided with a retractable flared portion, the diameter of which can be adjusted according to the diameter of the affected blood vessel, so that the edge of the flared portion can fit well with the inner wall of the blood vessel, so that the thrombus can be completely removed during the retrieval and collection process, and the thrombus can be prevented from remaining and falling off and overflowing into the blood circulation system. At the same time, the sheath has a large enough space to store the thrombus that is dragged back.

[0033] In some other embodiments, the thrombus removal device adopts the above-mentioned sheath tube assembly and also includes a single-lumen microwire balloon catheter, wherein the balloon and the cavity of the single-lumen microwire are assembled together, which can greatly reduce the outer diameter of the balloon catheter, and greatly improve its passability and pushing ability, so that the balloon catheter can accurately and quickly pass through the thrombus along the blood vessel wall, thereby adapting to lesions of different blood vessel diameters, and can pass through long-segment thrombi or thrombi with complex morphological structures, with strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, purposes and advantages of the present invention will become more apparent. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings without creative work. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same figure numbers in the figures represent the same or similar parts, and their repeated descriptions will be omitted. Some of the block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

[0035] Figure 1 It is a structural schematic diagram of a sheath tube assembly according to an embodiment of the present invention;

[0036] Figure 2 for Figure 1 A schematic structural diagram of a flared portion of a flared tube;

[0037] Figure 3 It is a schematic structural diagram of a balloon catheter in which the balloon is in a deflated state according to one embodiment of the present invention;

[0038] Figure 4 is a cross-sectional structural diagram of a microwire according to an embodiment of the present invention;

[0039] Figure 5 It is a schematic structural diagram of a balloon catheter in which the balloon is in an expanded state according to one embodiment of the present invention;

[0040] Figure 6 FIG. 4 is a schematic structural diagram of a thrombus removal device according to an embodiment of the present invention.

[0041] Reference numerals

[0042] 10 Sheath connector

[0043] 11 Sheath

[0044] 12 Expanded tube

[0045] 121 Flared part

[0046] 13 Flared cap

[0047] 14 Positioning piece

[0048] 21 microwire

[0049] 211 Cavity

[0050] 212 Side hole

[0051] 213 Tip

[0052] 22 Balloon

[0053] 23 Catheter seat

[0054] 24 Reinforcement pipe

[0055] 25 developer DETAILED DESCRIPTION

[0056] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the disclosure will be more comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0057] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like mean that the specific features, structures, materials or characteristics represented in conjunction with the embodiment or example are included in at least one embodiment or example of this specification. Moreover, the specific features, structures, materials or characteristics represented may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples and features of different embodiments or examples represented in this specification without contradiction.

[0058] Throughout the specification, when it is said that a device is "connected" to another device, this includes not only the situation of "direct connection" but also the situation of "indirect connection" by placing other elements therebetween. Terms indicating relative spaces such as "below" and "above" may be used to more easily explain the relationship of one device illustrated in the accompanying drawings relative to another device. Such terms refer not only to the meanings indicated in the accompanying drawings, but also to other meanings or operations of the device in use. For example, if the device in the accompanying drawings is turned over, a device that was described as being "below" other devices is described as being "above" other devices. Therefore, the exemplary term "below" includes both above and below. The device can be rotated 90° or other angles, and the terms representing relative spaces are interpreted accordingly.

[0059] Although the terms first, second, etc. are used to represent various elements in some examples, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, the first interface and the second interface, etc. are represented. Moreover, as used in this article, the singular forms "one", "one" and "the" are intended to also include plural forms, unless there is an opposite indication in the context. It should be further understood that the terms "comprising" and "including" indicate that there are the described features, steps, operations, elements, components, projects, kinds, and / or groups, but do not exclude the existence, occurrence or addition of one or more other features, steps, operations, elements, components, projects, kinds, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or mean any one or any combination. Therefore, "A, B or C" or "A, B and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C". Only when the combination of elements, functions, steps or operations is inherently mutually exclusive in some way, will there be an exception to this definition.

[0060] Although not defined differently, all terms, including technical and scientific terms used herein, have the same meaning as those generally understood by those skilled in the art to which this specification belongs. Terms defined in commonly used dictionaries are additionally interpreted as having meanings consistent with the relevant technical literature and the contents of the current disclosure, and unless defined, shall not be overly interpreted as ideal or very formal meanings.

[0061] In order to solve the existing technical problems, the present invention provides a sheath assembly, which includes a sheath joint, a sheath and a flared tube; the sheath is sleeved on the outside of the flared tube and its proximal end is connected to the sheath joint; the flared tube extends axially and has a channel for a balloon catheter to pass through, and the flared tube moves axially relative to the sheath; the distal end of the flared tube is provided with a flared portion, and the flared portion moves with the movement of the flared tube relative to the sheath, and is in a contracted state when inside the sheath, and in an extended state when outside the sheath. The sheath assembly of the thrombus removal device of the present invention has a retractable and adjustable flared portion, which can completely and without omission remove or drag the thrombus in blood vessels of different specifications into the flared sheath. Furthermore, the above-mentioned sheath assembly is combined with a single-lumen microfilament balloon catheter with good pushing performance, and the assembly structure is simple and the surgical operation is convenient, so that the thrombus can be quickly removed and the damage to the blood vessel wall can be minimized.

[0062] It should be noted that the distal end and the proximal end of the present invention are relative to the operator, the end closer to the operator is the proximal end, and the end farther from the operator is the distal end. "Axial" refers to a direction, orientation or line that is parallel or substantially parallel to the central axis of the sheath or the central axis of the tubular structure below; "radial" refers to a direction, orientation or line that is perpendicular or substantially perpendicular to the central axis of the sheath or the central axis of the tubular structure, and is sometimes used to describe circumferential characteristics.

[0063] The structures of the sheath tube assembly and the thrombus removal device of the present invention are further described below in conjunction with the embodiments and drawings. It should be understood that the specific embodiments are not intended to limit the protection scope of the present invention.

[0064] Figure 1 It is a structural schematic diagram of a sheath tube assembly according to an embodiment of the present invention, and the sheath tube assembly comprises a sheath tube connector 10, a sheath tube 11 of a tubular structure and a flared tube 12;

[0065] The sheath tube 11 is sleeved on the outside of the flared tube 12 and the proximal end of the sheath tube is connected to the sheath tube connector 10;

[0066] The flared tube 12 extends along the axial direction of the sheath tube and is axially movable relative to the sheath tube 11;

[0067] A flaring portion 121 is provided at the distal end of the flaring tube 12. The flaring portion 121 is retractable and can move axially relative to the sheath tube along with the flaring tube 12. When the flaring tube 12 is entirely within the sheath tube 11, the flaring portion 121 is in a contracted state. When the flaring portion 121 is at least partially outside the sheath tube 11, the flaring portion 121 is in an extended state.

[0068] The sheath is also called a catheter sheath, which is mainly used to guide the catheter, balloon catheter or other intravascular devices to enter the blood vessel smoothly. In order to enhance the pushing performance of the sheath, the sheath 11 may include an inner layer, an outer layer and a braided layer between the inner layer and the outer layer. The braided layer is woven from a wire material, and the shape of the wire material is not limited, and can be a round wire or a flat wire, etc. The material of the braided layer can be a stainless steel metal material, and the inner layer and / or the outer layer are polymer tubes. In the present invention, the braiding density (PPI) of the proximal end of the braided layer is greater than the braiding density of its distal end. Here, the braiding density (PPI) is the number of spirals or braiding nodes per unit inch, that is, the braiding density of the braided layer from the proximal end to the distal end is from dense to sparse. Preferably, the braiding density of the proximal braided layer is 80PPI, and the braiding density of the distal braided layer is 30PPI. The sheath with the above structure has good strength and support performance. Since the braiding density of the distal braided layer is less than the braiding density of the proximal braided layer, accordingly, the distal end of the sheath is relatively soft and easy to operate.

[0069] The flared tube 12 is disposed in the tubular sheath tube 11 and can move relative to the sheath tube 11 in the axial direction. The material of the flared tube 12 can be a polymer material, specifically a polymer material such as nylon, polytetrafluoroethylene (PTFE), etc. The flared tube 12 extends axially and has a passage for the balloon catheter to pass through, that is, it is also a hollow tubular structure. The distal end of the flared tube 12 is provided with a retractable flared portion 121. Figure 2 for Figure 1 The structure diagram of the expanded portion of the expanded tube of the embodiment of the present invention is shown in FIG. The material of the expanded portion 121 can also be a polymer material such as nylon and polytetrafluoroethylene. These polymer materials are formed into a structure with a memory function after being formed by a heat-forming process or a cold-forming process. That is, the expanded portion can be formed by a heat-forming process or a cold-forming process. Figure 2 For example, the expanded portion 121 in the extended state is a cone that expands gradually from the proximal end to the distal end, that is, the expanded portion 121 is a hollow cone structure, and its cross-section is a V-shaped trumpet structure. The proximal end of the expanded portion 121 is connected to the distal end of the expanded tube 12. In some embodiments, the expanded tube 12 and the expanded portion 121 are integrated. The expanded portion 121 can be formed by the distal end of the expanded tube 12 after expansion, heat treatment or expansion, cold treatment and finalization. The expanded portion 121 has a memory function. The expanded portion 121 is not limited to the hollow cone structure described above. For example, the expanded portion 121 can also be a hollow prism structure composed of four trapezoids, and the short side of the trapezoid is connected to the distal end of the expanded tube 12.

[0070] In some embodiments, the sheath tube 11 assembly further includes a flaring cap 13, which is connected to the proximal end of the flaring tube 12, and the rotation of the flaring cap 13 drives the flaring tube 12 to move axially relative to the sheath tube 11. Figure 1 In the embodiment, the flaring cap 13 is arranged at the proximal end of the flaring tube 12. When the flaring cap 13 rotates to drive the flaring tube 12 to move from the proximal end to the distal end, the flaring portion 121 of the flaring tube 12 switches from a contracted state in the distal end of the sheath tube 11 to a stretched state extending out of the distal end of the sheath tube 11.

[0071] like Figure 2 As shown, the expansion state of the flared portion can be adjusted by the length of the flared portion extending from the distal end of the sheath tube 11, that is, by rotating the flared cap 13. The three states a, b, and c in the figure represent three different degrees of expansion and non-expansion states. Preferably, when the flared portion is in the contracted state or the extended state, the radial dimension of the flared portion varies between 2 mm and 12 mm. The "radial dimension" referred to here refers to the distance between the farthest two points on the cross section of the flared portion at the maximum expansion. Taking the cross section of the flared portion as a circle as an example, the radial dimension of the flared portion is the diameter of the flared portion at the maximum expansion. Preferably, the inner diameter of the sheath 11 is 1.0mm to 2.5mm. For example, when the inner diameter of the sheath 11 is 2.5mm, the flared portion with a radial dimension of 2mm in a contracted state can move inside the sheath 11, and when the flared portion is in a fully extended state, the radial dimension of the flared portion can reach 12mm. The above-mentioned flared cap is used to adjust the length of the flared portion extending out of the distal end of the sheath 11, and then adjust the diameter of the flared portion, so that the diameter of the flared portion can be adjusted according to the diameter of the blood vessel during use to ensure that it can better fit the blood vessel.

[0072] In other embodiments, the sheath assembly also includes a positioning piece 14 detachably connected to the sheath connector 10, and the positioning piece 14 is arranged between the sheath connector 10 and the flaring cap 13. The positioning piece 14 can be set at a position, and when it abuts against the flaring cap, it limits the rotation of the flaring cap 13 toward the distal end. The position of the positioning piece 14 can be to ensure that the flaring portion 121 is in the distal end of the sheath 11, that is, the positioning piece 14 prevents the flaring portion 121 from being in an extended state, thereby ensuring the smoothness and passability of the sheath assembly in the blood vessel before the balloon catheter is delivered to the target position. When it is necessary to make the flared portion 121 into an extended state, the positioning piece 14 is removed from the sheath connector 10, and the flaring cap 13 is rotated toward the distal end to make the flared portion 121 at the distal end of the flared tube 12 extend from the distal end of the sheath 11 and open. The radial dimension diameter of the flared portion 121 can be adjusted according to the length of the flared portion 121, that is, the trumpet-shaped memory portion extending out of the distal end of the sheath 11, to ensure that the flared portion fits well with the blood vessel, forming a ready state for thrombus capture.

[0073] The present invention also provides a thrombus removal device, comprising the sheath assembly described above. In some embodiments, the thrombus removal device also includes a balloon catheter. The expanded tube 12 has a channel for the balloon catheter to pass through. The balloon catheter includes a microwire 21, a balloon 22 and a catheter seat 23.

[0074] Figure 3 This is a schematic structural diagram of a balloon catheter in a balloon in a contracted state according to an embodiment of the present invention; wherein, the proximal end of the microfilament 21 is connected to the catheter seat 23, and the balloon 22 is sleeved on the distal end of the microfilament 21; the balloon 22 can be selected according to the actual scenario, for example, it can be a compliant balloon, and the material of the balloon can be latex, or thermoplastic polyurethane elastomer rubber (Thermoplastic polyurethanes, TPU), etc.

[0075] Figure 4 2 is a cross-sectional structural diagram of a microwire according to an embodiment of the present invention, wherein the microwire 21 is provided with a hollow cavity 211 and a side hole 212, and the cavity 211 is connected to the balloon 22 through the side hole 212. The cavity 211 extends along the axial direction of the microwire 21, and a liquid such as a developer can be sequentially injected into the balloon 22 through the cavity at the proximal end of the microwire, the cavity at the distal end of the microwire, and the side hole 212, thereby expanding the balloon and forming a blockade against the thrombus. Figure 5 The structure diagram of a balloon catheter in which the balloon is in an expanded state according to an embodiment of the present invention is shown in FIG. Preferably, the diameter of the balloon 22 is 1 mm to 14 mm. The balloon can be fully expanded at 1-2 standard atmospheric pressures (atm). At this time, the balloon has good flexibility and low pressure, and will not cause damage to the blood vessels.

[0076] In the present invention, the microwire 21 may be a single layer or a multi-layer structure. Figure 4 As shown, when the microfilament has a double-layer structure, that is, it may include an inner layer and an outer layer. Preferably, the inner layer is a polyimide (PI) inner layer, and the outer layer is a segmented polyetheramide resin (Pebax) outer layer. In other embodiments, the inner layer is a polyimide PI inner layer, and the outer layer is a polyamide (PA) outer layer. The inner layer and outer layer of the double-layer microfilament are not limited to the above materials.

[0077] In some other embodiments, the microfilament 21 may also be a three-layer structure, that is, including an inner layer, a middle layer and an outer layer. Specifically, it may include an inner layer of high-density polyethylene (HDPE), a middle layer of linear low-density polyethylene (LLDPE) and an outer layer of segmented polyetheramide resin Pebax. The microfilament may also be a structure of more than four layers, which will not be described here. The multi-layer structure enables the microfilament to have higher mechanical properties, push tracking performance, and flexibility. The structure of the microfilament and the materials of each layer are not limited to the description.

[0078] In the microfilament 21 of the present invention, only a hollow cavity 211 is provided, and the radial dimension of the microfilament can be set between 0.4 mm and 1.0 mm. Compared with the existing microfilament, it has a smaller radial dimension. Here, the radial dimension refers to the distance between the two farthest points on the cross section. For example, when the cross section is circular, the radial dimension is the outer diameter. At the same time, the balloon 22 of the balloon catheter of the present invention is arranged at the side hole 212 of the microfilament 21, and the balloon 22 and the microfilament 21 form a sealed space. The liquid is directly infused into the balloon 22 through the cavity 211 and the side hole 212 to expand the balloon 22. The small size design of the microfilament 21 allows the balloon catheter of the present invention to have a smaller radial dimension. In the process of using the thrombus removal device, the balloon catheter can accurately and quickly pass through the thrombus along the blood vessel wall, can adapt to the lesions of different blood vessel diameters, can pass through long thrombi or thrombi with complex morphological structures, and has stronger adaptability.

[0079] Furthermore, the balloon catheter may further include a reinforcing tube 24, and the proximal end of the microwire 21 is connected to the catheter seat 23 through the reinforcing tube 24. The reinforcing tube 24 has a protective function and a transition function, and can prevent the microwire 21 from being bent and damaged.

[0080] A thrombus removal device including the above-mentioned sheath tube assembly and balloon catheter Figure 6 As shown, in this embodiment, the balloon catheter also includes a tip portion 213 connected to the distal end of the microfilament 21, and the outer diameter of the tip portion 213 gradually decreases in the axial direction from the proximal end to the distal end. The distal end of the microfilament 21 can be connected to the tip portion 213 by heat welding, laser welding or bonding. The tip portion can be made of materials such as elastomeric polymers, such as Pebax6033, etc. The microfilament with the tip portion does not damage the blood vessel when contacting the blood vessel wall, and the tip portion has a certain taper, which is convenient for passing through the lesion.

[0081] at the same time, Figure 6The balloon catheter of the embodiment may further include a developing part 25, which may be disposed at the proximal end of the balloon 22 or the distal end of the balloon 22. The developing part may be a ring-shaped structure of a microwire 21 sleeved at the proximal end or the distal end of the balloon 22. The developing part is made of a combination of one or more of platinum-iridium alloy, platinum-nickel alloy, platinum-tungsten alloy, tungsten, tantalum, tungsten-tantalum alloy and gold. The developing part of the above materials is visible under X-ray examination and can be used to position the balloon, facilitating the doctor's observation and positioning during surgery.

[0082] When using the thrombus removal device of the present invention, the following steps may be included:

[0083] a. Place the sheath assembly with the adjustable flaring portion into the target blood vessel, and then insert the balloon catheter without the balloon expanded into the blood vessel through the channel of the flaring tube. In this step, the flaring portion is retracted into the sheath, and the positioning member abuts against the flaring cap to prevent the flaring cap from rotating toward the distal end so that the flaring portion extends out of the distal end of the sheath;

[0084] b. Position the balloon at the distal end of the thrombus through the developing piece, remove the positioning piece, rotate the flaring cap to make the trumpet-shaped memory flaring part at the distal end of the flaring tube extend from the distal end of the sheath tube and open, and adjust the radial size of the flaring part by rotating the flaring cap to make it fit the inner wall of the blood vessel;

[0085] c. Expand the balloon and fit it to the blood vessel wall, slowly drag the balloon catheter proximally, and use the balloon to drag the thrombus into the expanded opening of the expanded part. Good fit with the expanded part can effectively prevent the thrombus from escaping.

[0086] The thrombus removal device of the present invention effectively prevents the escape of thrombus during the pulling back and collection process, realizes the complete removal of thrombus, prevents the thrombus from remaining or falling off and overflowing into the blood circulation system, and at the same time, the sheath has a large enough space to store the pulled back thrombus.

[0087] The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or basic features of the present application. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present application is limited by the attached claims rather than the above description, so it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present application. Any figure mark in the claims should not be regarded as limiting the claims involved.

Claims

1. A sheath tube assembly, characterized in that: It includes a sheath tube connector, a sheath tube of tubular structure and a flared tube; The sheath tube is sleeved on the outside of the flared tube, and the proximal end of the sheath tube is connected to the sheath tube connector; The flared tube extends along the axial direction of the sheath tube and is axially movable relative to the sheath tube; The distal end of the flared tube is provided with a flared portion, which can move axially with the flared tube relative to the sheath tube. When the flared portion is entirely within the sheath tube, it is in a contracted state, and when at least part of the flared portion is outside the sheath tube, it is in an extended state.

2. The sheath tube assembly according to claim 1, characterized in that: It also includes a flaring cap, which is connected to the proximal end of the flaring tube, and the rotation of the flaring cap drives the flaring tube to move axially relative to the sheath tube.

3. The sheath tube assembly according to claim 2, characterized in that: It also includes a positioning piece detachably connected to the sheath tube connector, wherein the positioning piece abuts against the distal end of the flaring cap to limit the rotation of the flaring cap toward the distal end.

4. The sheath tube assembly according to claim 1, characterized in that: The cross section of the flared portion in the extended state is trumpet-shaped.

5. The sheath tube assembly according to claim 1, characterized in that: When the flared portion is in the contracted state or the extended state, the radial dimension of the flared portion ranges from 2 mm to 12 mm.

6. The sheath tube assembly according to claim 1, characterized in that: The flared portion is formed by a heat setting or cold setting process; The material of the flared portion is a polymer material.

7. The sheath tube assembly according to claim 1, characterized in that: The sheath tube comprises an inner layer, an outer layer and a braided layer between the inner layer and the outer layer.

8. The sheath tube assembly according to claim 7, characterized in that: The braided layer is braided from silk materials, and the braiding density of the proximal end of the braided layer is greater than that of the distal end thereof; the inner layer and / or the outer layer is a polymer tube.

9. A thrombus removal device, characterized in that: The invention comprises the sheath tube assembly and the balloon catheter according to any one of claims 1 to 8, wherein the flared tube has a channel for the balloon catheter to pass through, and the balloon catheter comprises a microwire, a balloon and a catheter seat; The proximal end of the microwire is connected to the catheter seat, and the balloon sleeve is arranged on the distal end of the microwire; The microwire is provided with a hollow cavity and a side hole, and the cavity is connected with the balloon through the side hole.

10. The thrombus removal device according to claim 9, characterized in that: The radial dimension of the microwire is between 0.4 mm and 1.0 mm.

11. The thrombus removal device according to claim 9, characterized in that: The microfilaments are of a single-layer structure; or The microfilament has a double-layer structure, and the microfilament comprises a polyimide inner layer and a segmented polyetheramide resin outer layer, or the microfilament comprises a polyimide inner layer and a polyamide outer layer; or The microfilaments are of a three-layer structure, comprising a high-density polyethylene inner layer, a linear low-density polyethylene middle layer and a segmented polyetheramide resin outer layer; or The microfilaments have a structure of more than four layers.

12. The thrombus removal device according to claim 9, characterized in that: The balloon catheter also includes a reinforcing tube, and the proximal end of the microwire is connected to the catheter seat through the reinforcing tube.

13. The thrombus removal device according to claim 9, characterized in that: The balloon catheter further comprises a tip portion connected to the distal end of the microwire, and an outer diameter of the tip portion gradually decreases in an axial direction from the proximal end to the distal end.

14. The thrombus removal device according to claim 9, characterized in that: The balloon catheter further includes a developing component, which is disposed at the proximal end of the balloon or the distal end of the balloon.

Images