Delivery catheter and distal protection system

Abstract

The application particularly relates to a delivery catheter and a distal end protection system, wherein the delivery catheter comprises a tube body and a guide part, the guide part is arranged at the distal end of the tube body, and a guide surface is arranged on the end face of the end of the guide part away from the tube body. The guide part has a delivery channel coaxially arranged with the tube body, and the delivery channel has a first state and a second state which can be switched. In the first state, the delivery channel has a first inner diameter, and in the second state, the delivery channel has a second inner diameter. The first inner diameter is smaller than the second inner diameter and smaller than the inner diameter of the tube body. The delivery catheter can guide the recovery process of the protection umbrella assembly by using the guidance of the guide surface and the constraint of the delivery rod by the delivery channel, so that the distal end protection device and the delivery catheter always remain on the same axial center line, thereby solving the problem that the protection umbrella cannot be centered and thus cannot be put into the delivery catheter at one time due to the step difference between the delivery rod and the catheter.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical devices, and particularly relates to a delivery catheter and a distal protection system. BACKGROUND

[0002] Health is a common goal that mankind needs to face, and disease treatment is a common challenge for society. Cerebral stroke disease is one of the major high-incidence diseases that endanger life, mainly including ischemic stroke and hemorrhagic stroke.

[0003] Ischemic disease is one of the most common symptoms of stroke. The cause of ischemic stroke is that there is a small embolus on the inner wall of the blood vessel supplying the brain, which causes arterial embolism after falling off. The heart valve of patients with coronary heart disease complicated with atrial fibrillation is prone to mural thrombosis, and the embolus can block the cerebral blood vessels after falling off, which can also cause ischemic stroke. Other factors include hypertension, diabetes, hyperlipidemia, etc. In addition, intimal hyperplasia and hypertrophy caused by collagen disease, hypertension, arteriosclerosis, rheumatic heart disease or arteritis, blood disease, metabolic disease, etc., trauma of the carotid artery, tumor compression of the carotid artery, etc. can cause carotid artery stenosis and occlusion, or cause stroke due to blood vessel rupture and hemorrhage.

[0004] In recent years, globally, stroke is the second leading cause of human death after ischemic heart disease, and is the most important factor of human disability. Among them, more than 80% of strokes are ischemic strokes, and about 20% are hemorrhagic strokes. Ischemic stroke is mainly caused by carotid artery stenosis and intracranial vascular stenosis, leading to insufficient blood supply to the brain or cerebral embolism, while hemorrhagic stroke is mainly caused by rupture of cerebral aneurysm, leading to subarachnoid hemorrhage. In recent years, interventional instruments such as carotid artery stents, distal protection instruments and intracranial vascular stents have been developed for ischemic stroke, and coil and related stent technologies have been developed for interventional treatment of cerebral aneurysm, which have played a great role in the safety and effectiveness of treatment.

[0005] Ischemic disease is one of the most common symptoms of stroke. The cause of ischemic stroke is that there is a small embolus on the inner wall of the blood vessel supplying the brain, which causes arterial embolism after falling off. The heart valve of patients with coronary heart disease complicated with atrial fibrillation is prone to mural thrombosis, and the embolus can block the cerebral blood vessels after falling off, which can also cause ischemic stroke. Other factors include hypertension, diabetes, hyperlipidemia, etc. In addition, intimal hyperplasia and hypertrophy caused by collagen disease, hypertension, arteriosclerosis, rheumatic heart disease or arteritis, blood disease, metabolic disease, etc., trauma of the carotid artery, tumor compression of the carotid artery, etc. can cause carotid artery stenosis and occlusion, or cause stroke due to blood vessel rupture and hemorrhage.

[0006] Distal protector: mainly used in carotid artery stent intervention surgery (CAS) in the distal lesion of the blood vessels (intracranial internal carotid artery) to collect plaque, prevent distal cerebral embolization. The product is preloaded in a micro-conveying sheath (diameter 2.5-4F, about 0.83mm-1.33mm), after reaching the distal blood vessels, the sheath can be automatically restored to an umbrella shape after being withdrawn, which can effectively capture the thrombus and atherosclerotic plaque shed during the stent intervention surgery, thereby greatly increasing the safety of carotid artery stent surgery and reducing the incidence of postoperative complications.

[0007] At present, the proximal end and the distal end of the protection umbrella of the distal protection device are mainly connected and fixed by clamping the filter screen with the inner sleeve ring and the outer sleeve ring, so that the fixed end face has a large step difference with the conveying rod (as shown in Figure 1 illustrated), and the diameter difference between the conveying rod and the conveying catheter recovery end causes a large gap and is not on the same axis, which causes the protection umbrella to be jammed during retraction into the conveying catheter and cannot be retracted into the conveying catheter at one time, which may cause the operation time to be prolonged, increasing the risk during the operation. SUMMARY

[0008] The purpose of the present application is to at least solve the problem that the protection umbrella of the existing distal protector cannot be centered due to the step difference between the conveying rod and the catheter during retraction into the conveying catheter, causing jamming or failure to be retracted into the conveying catheter at one time. The purpose is achieved by the following technical solutions:

[0009] The present application provides a conveying catheter for conveying a distal protection device, the conveying catheter comprising a tube body and a guide portion, the guide portion being arranged at the distal end of the tube body, the guide portion having a conveying channel for the distal protection device to pass through, and the end face of the end of the guide portion away from the tube body being provided with a guide surface;

[0010] The conveying channel is coaxially arranged with the tube body, and the conveying channel has a switchable first state and a second state, in the first state, the conveying channel has a first inner diameter, in the second state, the conveying channel has a second inner diameter, the first inner diameter is smaller than the second inner diameter, and smaller than the inner diameter of the tube body.

[0011] According to the delivery catheter of the present application, by arranging the guide part at the distal end of the tube body, and arranging the delivery channel of the guide part coaxially with the tube body, the delivery channel has the first state and the second state with different inner diameters, so that when the protection umbrella assembly of the distal end protection device is retracted into the delivery channel, the delivery rod can be constrained by the delivery channel of the guide part, and then the distal end protection device and the delivery catheter are kept on the same axial center line. At the same time, by arranging the guide surface on the guide part, the protection umbrella assembly can be smoothly retracted into the delivery catheter by the guidance of the guide surface and the constraint of the delivery catheter. The problems that the protection umbrella cannot be retracted into the delivery catheter at one time due to the step difference between the delivery rod and the catheter, and the operation process needs to be repeated, can be effectively solved, the operation time can be effectively shortened, and the risk of causing vascular spasm due to excessive operation stimulation of the blood vessels during the operation can be reduced.

[0012] In addition, the delivery catheter according to the present application can also have the following additional technical features:

[0013] In some embodiments of the present application, along the axial direction of the tube body, the guide part has a first cavity and a second cavity arranged in sequence, the second cavity, the first cavity and the tube body are in sequence communication, the first cavity and the second cavity are coaxially arranged, and the inner diameter of the second cavity is smaller than the inner diameter of the first cavity, and the second cavity is formed with the first inner diameter and the second inner diameter.

[0014] In some embodiments of the present application, the inner diameter of the second cavity gradually decreases and then gradually increases along a first direction, and the first direction is the direction from the proximal end of the tube body to the distal end of the tube body.

[0015] In some embodiments of the present application, the guide part has a third cavity, and the third cavity is arranged outside the second cavity.

[0016] In some embodiments of the present application, the guide part has an outer layer mesh tube and an inner layer mesh tube, and the outer layer mesh tube and the inner layer mesh tube are connected and form the first cavity, the second cavity and the third cavity.

[0017] In some embodiments of the present application, the guide part is a metal woven piece.

[0018] In some embodiments of the present application, the guide part and the tube body are an integral molded piece, the outer diameter of the guide part gradually decreases along a first direction, the first direction is the direction from the proximal end of the tube body to the distal end of the tube body, and the inner diameter of the guide part is greater than the outer diameter of the distal end protection device.

[0019] In some embodiments of the present application, the guide part is a polymer member, and a plurality of communication holes are formed in the guide part and arranged around the axis of the tube body.

[0020] In some embodiments of the present application, the distal end of the tube body is provided with a developing member, which is arranged at a distance from the guide part along the axial direction of the tube body.

[0021] The second aspect of the present application also provides a distal protection system, which comprises the delivery catheter of the present application.

[0022] Compared with the prior art, the distal protection system of the present application has the technical advantages of the delivery catheter described above, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0023] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of preferred embodiments, and are not meant to limit the present application. Furthermore, the same reference numerals are intended to denote the same components throughout the accompanying drawings. In the drawings:

[0024] Figure 1 Structure schematic view of the existing distal protection system during recovery in a blood vessel;

[0025] Figure 2 Structure schematic view of one of the distal protection systems according to embodiments of the present application is shown schematically;

[0026] Figure 3 Structure schematic view of the distal protection device shown in Figure 2

[0027] Structure schematic view of the distal protection device shown in Figure 4 Figure 3 Structure schematic view of the distal protection device shown in

[0028] Figure 5 Figure 2 Structure schematic view of the delivery catheter shown in

[0029] Figure 6 Structure schematic view of the distal protection device shown in Figure 5

[0030] Structure schematic view of the distal protection device shown in Figure 7 Figure 2 Structure schematic view of the guide part shown in

[0031] Figure 8 Figure 2 Structure schematic view of the guide part shown in ​​​​

[0032] Figure 9 for Figure 2 A schematic structural diagram of the guide portion shown in FIG. 1 from a third viewing angle;

[0033] Figure 10 The structure diagram of the braided mesh tube according to the embodiment of the present invention is schematically shown;

[0034] Figure 11 for Figure 10 A schematic diagram of the partially enlarged structure of C shown in FIG;

[0035] Figure 12 for Figure 2 Schematic diagram of the structure of the distal protection device entering the delivery catheter during retrieval;

[0036] Figure 13 for Figure 10 Schematic diagram of the structural change of the guide portion during the recovery process shown in ;

[0037] Figure 14 Schematically shows one structural diagram of a remote protection system according to an embodiment of the present invention;

[0038] Figure 15 for Figure 14 A schematic structural diagram of the delivery catheter shown in ;

[0039] Figure 16 for Figure 15 A schematic diagram of the partially enlarged structure of D shown in FIG;

[0040] Figure 17 for Figure 14 A schematic structural diagram of the guide portion shown in FIG. 1 at a certain viewing angle;

[0041] Figure 18 for Figure 14 FIG. 1 is a schematic structural diagram of the guide portion from another perspective.

[0042] The symbols in the accompanying drawings represent the following:

[0043] 1000, distal protection system; 2000, blood vessels;

[0044] 100. Delivery catheter; 200. Distal protection device;

[0045] 10. Catheter; 11. Body; 12. Endometrium; 13. Guide portion;

[0046] 20. Connector;

[0047] 30. Developing parts;

[0048] 40, metal braid; 401, outer net tube; 402, inner net tube;

[0049] 41, first cavity; 42, second cavity; 421, inner horn; 422, outer horn; 43, third cavity; 431, outer round corner; 432, inner round corner;

[0050] 50, polymer member; 51, inlet; 52, communication hole; 53, guide surface;

[0051] 60, guide wire assembly; 61, delivery rod; 611, break point; 62, developing spring;

[0052] 70, limiting member;

[0053] 80, protection umbrella assembly; 81, first developing ring; 82, second developing ring; 821, inner ring; 822, outer ring; 83, filter screen; 84, developing wire;

[0054] 90, braided net tube; 91, metal wire. DETAILED DESCRIPTION

[0055] Example embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings. While example embodiments of the present disclosure are shown in the drawings, it is understood that the present disclosure can be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0056] It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "includes", "including" and "has" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order in which they are described, unless specifically identified as an order dependent step. It is also to be understood that additional or alternative steps can be employed.

[0057] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates otherwise, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0058] For ease of description, spatially relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figures, such as "inside," "outside," "inside," "outside," "below," "beneath," "above," and the like. Such spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is flipped, an element described as "below" or "below" another element or feature would then be oriented as "above" or "above" another element or feature. Thus, the example term "below" can include both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or in other orientations) and the spatially relative descriptors used herein are interpreted accordingly.

[0059] To more clearly describe the structure of this application, the terms "proximal" and "distal" are defined herein as commonly used in the field of interventional medicine. Specifically, "distal" refers to the end away from the operator during the surgical procedure, "proximal" refers to the end closer to the operator during the surgical procedure, "axial" refers to the length direction, and "radial" refers to the direction perpendicular to the "axial" direction.

[0060] like Figures 1-18 As shown, the present invention proposes a delivery catheter 100 for delivering a distal protection device 200, so as to solve the problem that when the protective umbrella of the existing distal protector is put into the delivery catheter 100, it cannot be aligned due to the step difference between the delivery rod 61 and the catheter 10, resulting in jamming or inability to be put into the delivery catheter 100 at one time.

[0061] The overall design of the delivery catheter 100 includes a tube body 11 and a guide part 13. The guide part 13 is arranged at the distal end of the tube body 11. The guide part 13 has a delivery channel for the distal protection device 200 to pass through. The end face of the end of the guide part 13 away from the tube body 11 is provided with a guide surface 53. At the same time, the delivery channel is coaxially arranged with the tube body 11. The delivery channel has a first state and a second state which can be switched. In the first state, the delivery channel has a first inner diameter. In the second state, the delivery channel has a second inner diameter. The first inner diameter is smaller than the second inner diameter. The first inner diameter is smaller than the inner diameter of the tube body 11.

[0062] Specifically, by arranging the guide part 13 at the distal end of the tube body 11 and arranging the delivery channel of the guide part 13 coaxially with the tube body 11, the delivery channel has a first state and a second state with different inner diameters. When the protection umbrella of the distal protection device 200 is retracted into the delivery channel, the delivery rod 61 can be constrained by the delivery channel of the guide part 13, so that the distal protection device 200 and the delivery catheter 100 are kept on the same axial center line. At the same time, by arranging the guide surface 53 on the guide part 13, the protection umbrella can be smoothly retracted into the delivery catheter 100 by using the guidance of the guide surface 53 and cooperating with the constraint of the delivery catheter 100. The problem that the protection umbrella cannot be centered and causes jamming or cannot be retracted into the delivery catheter 100 at one time due to the step difference between the delivery rod 61 and the delivery catheter 100 when the protection umbrella is retracted into the delivery catheter 100 can be effectively solved. The operation process is repeated to retract the operation. The operation time is effectively shortened. The operation is reduced. The risk of blood vessel 2000 spasm caused by excessive stimulation of blood vessel 2000 is reduced.

[0063] It should be understood that the delivery catheter 100 is used to deliver the distal protection device 200. As shown in Figure 2 and Figure 3 The distal protection device 200 includes a guide wire assembly 60, a limiting part 70 and a protection umbrella assembly 80. The guide wire assembly 60 includes a delivery rod 61 and a developing spring 62 arranged in sequence along a first direction a. Along the first direction a, the delivery rod 61 has a first section and a second section arranged in sequence. The diameter of the first section is greater than the diameter of the second section. The first section is provided with a breaking point 611. The second section is connected with the developing spring 62 at the end away from the first section. That is, the developing spring 62 is fixed at the distal end of the delivery rod 61. In this embodiment, the developing spring 62 is fixed on the delivery rod 61 by welding or bonding. The developing spring 62 is made of high-density noble metal such as platinum-iridium, platinum-tungsten, tantalum, gold, silver, platinum-silver and platinum-gold. Therefore, the position of the delivery rod 61 in the blood vessel 2000 can be determined by DSA subtraction technology during the operation. At the same time, the distal end of the developing spring 62 is welded or bonded with the delivery rod 61 to form a hemispherical shape, so as to prevent the protection umbrella assembly 80 from being pierced when the protection umbrella assembly 80 is released.

[0064] In the embodiment, the limiting member 70 and the umbrella assembly 80 are arranged on the first section. The umbrella assembly 80 can move along the first direction a on the delivery rod 61, and the limiting member 70 can limit the moving distance of the umbrella assembly 80. In actual use, when the operator applies a pushing force or a pulling force to the delivery rod 61, the pushing force or the pulling force is transmitted from the limiting member 70 on the delivery rod 61 to the umbrella assembly 80 to push or retract the umbrella assembly 80, thereby completing the releasing process and the recovering process. In the embodiment, the limiting member 70 is a tubular structure and is sleeved on the first section. Optionally, the limiting member 70 has a first spacing with the distal end of the delivery rod 61, and the first spacing is in a range of 20 mm-50 mm.

[0065] As shown in Figure 2 and Figure 3 , along the first direction a, the umbrella assembly 80 includes a first developing ring 81, a filter screen 83, a developing wire 84 and a second developing ring 82. The filter screen 83 is made of a nickel-titanium wire 91 with shape memory properties, is woven into a mesh tube, and is made after heat treatment and shaping with a special mold. The filter screen 83 is designed as a horn structure and is used to capture materials such as emboli and plaques that block the blood vessels 2000 after release, thereby preventing stroke caused by blockage of the blood vessels 2000.

[0066] In the embodiment, as shown in Figure 4 , the distal end of the filter screen 83 is clamped and fixed by an inner ring 821 and an outer ring 822, and is fused by welding of the outer end face to form the second developing ring 82. The inner ring 821 and the outer ring 822 are made of developing materials. Optionally, the developing materials can be one or more of platinum-iridium, platinum-tungsten, tantalum, gold, silver, platinum-silver, platinum-gold and other high-density noble metals, so that the developing effect can be achieved under the DSA subtraction technology, thereby accurately determining the release position of the umbrella assembly 80 during the operation. Optionally, the outer diameter of the outer ring 822 is 0.40 mm-0.80 mm, the inner diameter of the outer ring 822 is 0.30 mm-0.60 mm, and the length of the outer ring 822 is 1.0 mm-2.0 mm. The inner ring 821 is arranged inside the outer ring 822, the outer diameter of the inner ring 821 is 0.20 mm-0.50 mm, the inner diameter of the inner ring 821 is 0.10 mm-0.30 mm, and the length L of the inner ring 821 is 1.0-2.0 mm. In the embodiment, the first developing ring 81 has the same structure as the second developing ring 82, that is, the inner ring 821 and the outer ring 822 are clamped and fused by welding of the end face of the proximal end, thereby fixing the filter screen 83 and the developing wire 84.

[0067] It should be further understood that the area of the largest mesh hole of the filter screen 83 is not greater than 0.10 mm 2 . In this way, the area of the largest mesh hole of the filter screen 83 is not greater than 0.10 mm 2embolization material. Meanwhile, a loop of a radiopaque wire 84 is sutured at the trumpet mouth of the proximal end of the filter screen 83. In the present embodiment, the radiopaque wire 84 is made of one or more of platinum-iridium, tantalum, gold, platinum-silver, cobalt-chromium-platinum, and other radiopaque noble metals, and has a diameter of 0.03 mm to 0.08 mm. By limiting the diameter of the radiopaque wire 84, the radiopaque wire 84 can be visualized under DSA subtraction technology during the operation, so that the opening of the filter screen 83 can be observed, and it can be determined whether the open end (trumpet mouth) of the filter screen 83 is in apposition with the blood vessel 2000.

[0068] As shown in Figure 2 , Figure 5 , Figure 14 and Figure 15 , the delivery catheter 100 includes, in sequence along the first direction a, a connector 20, a catheter 10, and a guide portion 13. The connector 20 is a standard luer connector 20 made by injection molding and fixedly bonded to the proximal end of the catheter 10. The connector 20 can be connected to a Y valve, a hemostatic valve, or other connectors during the operation, which will not be described in detail here.

[0069] In the present embodiment, the inner lumen diameter of the catheter 10 is 1.0 mm to 1.2 mm, the outer diameter of the catheter 10 is 1.3 mm to 1.5 mm, and the total length of the catheter 10 is 1800 ± 20 mm. Specifically, the catheter 10 includes a tube body 11 and an inner membrane 12. The inner membrane 12 is attached to the inner wall of the tube body 11, which not only facilitates the delivery of the distal protection device 200, but also reduces damage to the distal protection device 200 during delivery. Optionally, the tube body 11 is made of PEBAX polymer material, and the inner membrane 12 is made of PTFE.

[0070] It should be further understood that the distal end of the tube body 11 is provided with a radiopaque member 30, which is spaced apart from the guide portion 13 along the axial direction of the tube body 11. By providing the radiopaque member 30, the position of the distal end of the delivery catheter 100 in the blood vessel 2000 can be accurately observed during the operation, which helps to further improve the accuracy of the operation. As shown in Figure 5 and Figure 6As shown, in the present embodiment, the developing member 30 is arranged between the PTFE inner film 12 and the catheter 10, and is embedded in the inner wall of the catheter 10. Alternatively, the developing member 30 is arranged in a ring structure, the developing member 30 has an outer diameter of 1.26-1.46 mm, a wall thickness of 0.1-0.2 mm, and a width of 1.0 mm, and is made of one or more of platinum-iridium, platinum-tungsten, tantalum, gold, silver, platinum-silver, platinum-gold, and other high-density noble metals. In this way, the distal end of the catheter 10 can be made visible during the operation, so that the doctor can determine the position of the delivery catheter 100 by the developing member 30. It can be understood that the tube body 11 is made of PEBAX high molecular material, and the PTFE inner film 12 and the developing member 30 are integrally formed by extrusion molding.

[0071] It can be understood that the guide portion 13 is arranged at the distal end of the tube body 11, and the guide surface 53 is arranged on the end face of the end of the guide portion 13 away from the tube body 11. The guide portion 13 and the tube body 11 can be a split structure, and the guide portion 13 can be fixed on the tube body 11 by hot melting technology and a tearable heat shrink tube. Of course, the guide portion 13 and the tube body 11 can be an integral structure, which helps to further reduce the manufacturing difficulty of the delivery catheter 100. The guide portion 13 has a delivery channel for the distal end protection device 200 to pass through, and the delivery channel is coaxially arranged with the tube body 11. The delivery channel has a first state and a second state. When the distal end protection device 200 is not arranged in the catheter 10, the guide portion 13 is in a natural state, i.e., the first state, and at this time, the delivery channel has a first inner diameter. When the distal end protection device 200 is arranged in the catheter 10, because the outer diameter of the first developing ring 81 or the second developing ring 82 is larger than the first inner diameter, the first developing ring 81 or the second developing ring 82 changes the inner diameter of the delivery channel when passing through the guide portion 13, so as to ensure that the first developing ring 81 or the second developing ring 82 can pass through the guide portion 13. At this time, the delivery channel has a second inner diameter, i.e., the delivery channel is in the second state, and the guide portion 13 has a restoring force for switching from the second state to the first state. Therefore, when the distal end protection device 200 passes through the delivery channel, the delivery channel can be switched between the first state and the second state. The delivery channel has the first inner diameter in the first state, and has the second inner diameter in the second state. The first inner diameter is smaller than the second inner diameter, and is smaller than the inner diameter of the tube body 11.

[0072] In the treatment of ischemic disease surgery, the delivery catheter 100 is used to place the distal protection device at a distance of 3-5 cm from the lesion, and then release, so that the distal protection device 200 can capture and recover the thrombus and plaque dropped during the operation process, prevent the distal blood vessel 2000 from being blocked and cause stroke disease. At the same time, the distal protection device 200 can be delivered to the target position by pushing the delivery catheter 100, and released and recovered from the target position. When recovering, the distal protection device 200 can be retracted into the delivery catheter 100 under the action of the delivery rod 61, at this time, the guide part 13 of the delivery catheter 100 can guide the protection umbrella assembly 80 into the delivery catheter 100, and constrain the delivery catheter 100 and the delivery rod 61 to keep the same axial center line, so as to solve the problem that the protection umbrella cannot be retracted into the delivery catheter 100 at one time due to the step difference between the delivery rod 61 and the catheter 10, avoid repeated retraction operation during the operation, effectively shorten the operation time, and reduce the risk of causing blood vessel 2000 spasm due to excessive operation stimulation of blood vessel 2000.

[0073] It should be understood that when the guide part 13 and the pipe body 11 are provided in a split structure, the guide part 13 can be made of metal or high polymer material. As shown in Figures 2-13 In this embodiment, the guide part 13 is provided as a metal braid 40, at this time, by using the characteristics of metal and the braided structure, the guide part 13 has better constraint, which is helpful to further ensure that the delivery rod 61 and the delivery catheter 100 can always be on the same center axis during the recovery of the protection umbrella assembly 80, and avoid the problem of multiple recovery or unable to recover due to jamming. As shown in Figure 10 and Figure 11 As shown in

[0074] Further, as shown in Figure 7 Along the axial direction of the pipe body 11, the guide part 13 has a first cavity 41 and a second cavity 42 arranged in sequence, the second cavity 42, the first cavity 41 and the pipe body 11 are sequentially communicated, the first cavity 41 and the second cavity 42 are coaxially arranged, the inner diameter of the second cavity 42 is smaller than that of the first cavity 41, and the second cavity 42 is formed with a first inner diameter and a second inner diameter.

[0075] Specifically, by defining the guide part 13 to have the first cavity 41 and the second cavity 42 arranged in sequence, the first cavity 41 can transit the connection between the inside of the tube body 11 and the second cavity 42, and the second cavity 42 has sufficient deformation space, and the driving force for the second cavity 42 to return to the first state, which helps to ensure that the second cavity 42 can constrain the guide wire assembly 60, so that the delivery rod 61 and the catheter 10 are maintained on the same axial center line.

[0076] It should be understood that, as Figures 6-9 shown, the guide part 13 is made of a woven mesh tube 90 and has the first cavity 41 and the second cavity 42. In this embodiment, the inner diameter of the first cavity 41 is the same as the outer diameter of the tube body 11, and the first cavity 41 and the second cavity 42 have a tapered structure arranged in the first direction a. At this time, the distal end of the tube body 11 can be inserted into the first cavity 41 of the guide part 13 and connected together by heat melting technology and a tearable heat shrink tube. Alternatively, the first cavity 41 is entirely sleeved on the tube body 11 and connected with the distal end of the tube body 11. Of course, in addition to this, the first cavity 41 can be partially sleeved on the tube body 11, and the connection of the guide part 13 and the tube body 11 can also be achieved. At the same time, the arrangement of the tapered structure can ensure that the second cavity 42 has a tendency to move radially towards the tube body 11 or in the first direction a during the movement of the guide wire assembly 60, which helps to avoid the second cavity 42 moving away from the tube body 11, thereby avoiding the situation that the distal end of the tube body 11 is blocked.

[0077] It should be pointed out that the guide part 13 can be arranged as Figures 6-9 shown structure, or other structures. When arranged as other structures, the gradual change of the tapered structure can be uniform or non-uniform, so as to ensure that the movement of the second cavity 42 is radial to the tube body 11 or in the first direction a. At the same time, the first cavity 41 can also be accommodated inside the tube body 11, and at this time, the second cavity 42 is located outside the tube body 11.

[0078] Further, the inner diameter of the second cavity 42 gradually decreases and then gradually increases in the first direction, and the first direction is the direction from the proximal end of the tube body 11 to the distal end of the tube body 11.

[0079] Specifically, by defining the inner diameter of the second cavity 42 to gradually decrease and then gradually increase in the first direction, guide surfaces can be formed at both ends of the second cavity 42, so as to facilitate the threading of the protection umbrella assembly 80 in the second cavity 42, and help to improve the efficiency of the operation.

[0080] It should be understood that, as Figures 5-7As shown, along the first direction a, the inner diameter of the second cavity 42 gradually decreases first and then gradually increases, so that the two ends of the second cavity 42 form a horn-shaped guide surface 53. For the sake of description, the guide surface 53 of the end of the second cavity 42 facing the tube body 11 is referred to as the inner horn 421, and the guide surface 53 of the end of the second cavity 42 away from the tube body 11 is referred to as the outer horn 422. In this way, not only is it convenient to quickly guide and constrain the protection umbrella assembly 80 when the guide wire assembly 60 is recovered, but it also ensures that the protection umbrella assembly 80 is quickly output when it is pushed, and in combination with the constraint of the second cavity 42 on the push rod, it helps to reduce the contact between the guide wire assembly 60 and the inner wall of the blood vessel 2000, thereby improving the safety of the operation.

[0081] It should be noted that the two ends of the second cavity 42 can also be provided in a circular truncated cone shape to ensure quick guidance of the protection umbrella assembly 80.

[0082] Further, the guide portion 13 has a third cavity 43, and the third cavity 43 is annularly arranged outside the second cavity 42.

[0083] Specifically, the arrangement of the third cavity 43 helps to further constrain the movement trend of the guide portion 13 when the delivery channel switches between the first state and the second state, that is, the distal end of the guide portion 13 moves away from the tube body 11, and the second cavity 42 moves along the radial direction of the tube body 11, which helps to avoid the situation that the guide portion 13 blocks the tube body 11, thereby effectively improving the use effect of the delivery catheter 100.

[0084] It should be understood that, as Figures 5-7 As shown, after the woven mesh tube 90 is fixed and heat treated through a special mold, the above-mentioned three-cavity two-horn structure is formed, wherein the three cavities refer to the first cavity 41 and the second cavity 42 arranged in sequence, and the third cavity 43 annularly arranged outside the second cavity 42. The two horns refer to the horn structure formed at the two ends of the second cavity 42 along the axial direction of the tube body 11. Alternatively, the outer diameter of the third cavity 43 is less than or equal to the outer diameter of the tube body 11, which on the one hand can avoid that the radial dimension of the distal end of the catheter 10 is too large, thereby affecting the use of the catheter 10, and on the other hand, when the guide wire assembly 60 passes through the second cavity 42, the third cavity 43 has a smaller movement space in the radial direction, thereby reducing the contact between the guide portion 13 and the blood vessel 2000.

[0085] It needs to be further understood that the guide part 13 has an outer layer mesh tube 401 and an inner layer mesh tube 402, which are connected and form the first cavity 41, the second cavity 42 and the third cavity 43. The guide part 13 is provided as a two-layer structure, which helps to improve the constraint effect of the guide part 13 itself and ensure that the second cavity 42 has a tendency to move in the first direction a. Moreover, it can also improve the connection effect of the guide part 13 and the tube body 11. Since the guide part 13 is a metal woven piece 40, the outer layer mesh tube 401 and the inner layer mesh tube 402 can be formed by folding and fixed on the tube body 11 together, which helps to further ensure the fixing, guiding and restraining effects of the guide part 13.

[0086] It needs to be pointed out that along the radial direction of the tube body 11, two corresponding outer fillets 431 and inner fillets 432 are formed at the distal end of the third cavity 43, wherein the inner fillet 432 is formed as the above-mentioned flared structure, that is, the guide surface 53. At the same time, the outer fillet 431 is provided, which helps to further reduce the friction between the guide part 13 and the blood vessel 2000, thereby ensuring the use effect of the guide part 13.

[0087] Specifically, as shown in Figures 6-11 The guide part 13 is a Tip head provided at the distal end of the delivery catheter 100. The Tip head is a ring-shaped mesh tube Tip head structure obtained by folding and fixing the woven mesh tube 90 on a special mold and then heat treating. The woven mesh tube 90 is a metal piece. After folding, the woven mesh tube 90 forms an inner layer mesh tube 402 and an outer layer mesh tube 401. The free ends of the inner layer mesh tube 402 and the outer layer mesh tube 401 are connected together to enclose the first cavity 41, the second cavity 42 and the third cavity 43. At this time, the third cavity 43 is a hollow cavity (similar to a life buoy inflation cavity) rotating 360° radially around the center axis of the woven mesh tube 90. The outer side of the third cavity 43 is the outer layer woven mesh tube 90 after folding and shaping. The end of the third cavity 43 away from the first cavity 41 forms a guide structure. The guide structure is that the outer layer mesh tube 401 is folded inward to form an outer fillet 431 transition arc surface, and then transitions to the second cavity 42 on the inside, while forming an inner fillet 432 transition arc surface, that is, a flared structure (guide surface 53). The flared structure is beneficial to guide the protection umbrella assembly 80 into the delivery catheter 100 when the protection umbrella is recovered. The diameter of the second cavity 42 is greater than the diameter of the delivery rod 61. The inner layer mesh tube 402 at the position of the second cavity 42 binds the delivery rod 61 in the radial direction, so that the delivery rod 61 of the guide wire assembly 60 is on the same axial center line as the delivery catheter 100.

[0088] When the protection umbrella assembly 80 is recovered, the push delivery catheter 100 is close to the first developing ring 81 of the protection umbrella assembly 80, the protection umbrella assembly 80 is guided and constrained by the horn structure of the Tip head, so that the delivery rod 61 is centered with the catheter 10 head end, and is smoothly received in the catheter 10, effectively solving the problem of jamming or unable to recover due to the step difference between the delivery rod 61 and the developing ring of the protection umbrella assembly 80, and the delivery rod 61 and the catheter 10 are not on the same axial center line, avoiding the blood vessel 2000 spasm caused by the long operation time and other intraoperative complications, and reducing the operation risk.

[0089] The first cavity 41 is a cavity formed by the second cavity 42 after the inner layer net tube 402 and the outer layer net tube 401 are shaped. The size of the first cavity 41 is similar to the size of the inner cavity of the tube body 11. At this time, the radial outer side of the first cavity 41 is the Tip head net tube tube body composed of the inner layer net tube 402 and the outer layer net tube 401. The Tip head net tube tube body and the tube body 11 are connected and fixed by melting the polymer material of the tube body 11 through hot melting technology, forming the Tip head of the delivery catheter 100. The first cavity 41 and the inner cavity of the tube body 11 together form the inner cavity of the delivery catheter 100, which can accommodate the protection umbrella assembly 80 and the recovered thrombus plaque when the guide wire assembly 60 is recovered, and withdraws them together with the delivery catheter 100 from the body, preventing the thrombus plaque from flowing to the distal end of the blood vessel 2000 and causing stroke.

[0090] When the Tip head and the delivery catheter 100 are fixed, the inner cavity of the catheter 10 is first supported by using a mandrel mold, then the Tip head is sleeved on the outer side of the distal end of the tube body 11, and then a tearable heat shrink tube is sleeved on the outer side. Then the polymer material of the tube body 11 is melted and adhered to the metal wire 91 of the Tip head by hot melting technology, and after cooling and shaping, the Tip head is fixed to the distal end of the tube body 11. Then tear off the tearable heat shrink tube, and the fixation of the Tip head and the catheter 10 is completed.

[0091] As Figure 12 and Figure 13As shown, the protection umbrella assembly 80 is retracted into the delivery catheter 100. Before the protection umbrella assembly 80 is retracted, the tip head is in a natural open state, at this time, the delivery rod 61 is in the same axis with the catheter 10 under the constraint of the woven tip head; when the operator applies a pulling force to the delivery rod 61, the pulling force is transmitted to the protection umbrella assembly 80 through the limiting member 70, so that the protection umbrella assembly 80 moves into the catheter 10 and the first developing ring 81 is retracted into the catheter 10, at this time, the first developing ring 81 is smoothly retracted into the catheter 10 under the guidance of the flared structure (inner fillet 432) of the tip head, and the inner circle of the tip head is expanded under the extrusion force, so that the protection umbrella is smoothly retracted into the catheter 10, solving the jamming problem caused by the fact that the distal protection device 200 is not in the same axis when it is retracted into the catheter 10, thereby smoothly achieving one-time retraction into the catheter 10, avoiding repeated retraction operation during the operation, effectively shortening the operation time, and reducing the risk of blood vessel 2000 spasm caused by excessive operation. At the same time, during the retraction of the protection umbrella assembly 80 into the catheter 10, the tip head is extruded and the mesh size is reduced, which can prevent the thrombus in the catheter 10 from flowing to the distal end of the blood vessel 2000 again, effectively preventing the distal blood vessel 2000 from being blocked to cause stroke.

[0092] It should be noted that in addition to the above-mentioned ring-shaped mesh tip head structure, the guide portion 13 can also be provided in other structures to have the tendency to recover from the second state to the first state, i.e. the constraint force, and the guide surface 53 (outer flared mouth 422 structure) at the distal end of the guide portion 13, which will not be limited here.

[0093] In some other embodiments of the present application, when the guide portion 13 and the pipe body 11 are integrally formed, Figures 14-18 As shown, the outer diameter of the guide portion 13 gradually decreases along the first direction a, and the inner diameter of the guide portion 13 is greater than the outer diameter of the distal protection device 200. By integrally forming the guide portion 13 and the pipe body 11, it is convenient to reduce the manufacturing difficulty of the catheter 10, and at the same time, limiting the outer diameter of the guide portion 13 to gradually decrease along the first direction a helps to ensure that the inlet 51 at the distal end of the guide portion 13 is coaxially arranged with the pipe body 11, thereby ensuring the constraint of the guide portion 13 to the distal protection device 200.

[0094] Still as Figures 14-18As shown, the outer diameter of the guide portion 13 per unit length gradually decreases along the first direction a. Optionally, the guide portion 13 is in a semi-spherical structure, which helps to reduce the damage to the blood vessel 2000 when the catheter 10 is pushed. At this time, the inlet 51 at the distal end of the guide portion 13 is larger than the outer diameter of the distal protection device 200, which helps to ensure the delivery effect of the guide wire assembly 60. Along the first direction a, both ends of the inlet 51 are provided with a rounded corner, which forms the guide surface 53 described above, so as to ensure the rapid guidance of the guide portion 13 to the guide wire assembly 60, and further improve the use effect of the delivery catheter 100.

[0095] It should be pointed out that the material of the guide portion 13 and the pipe body 11 can be the same or different. At this time, the inlet 51 of the guide portion 13 is the first inner diameter described above. At this time, the guide portion 13 has a deformation ability, and when the umbrella protection assembly 80 passes through the inlet 51, the movement of the umbrella protection assembly 80 can drive the inlet 51 to expand along the radial direction of the pipe body 11 and form a second inner diameter, thereby ensuring the delivery of the umbrella protection assembly 80.

[0096] In addition, the inlet 51 at the distal end of the guide portion 13 is slightly larger than the outer diameter of the first and second developing rings 81 and 82. Slightly larger means that the outer diameter of the first developing ring 81 is 85%-95% of the minimum inner diameter (inlet 51) of the guide portion 13. Optionally, the outer diameter of the first developing ring 81 is 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, or 95% of the inner diameter of the inlet 51. In this embodiment, the outer diameter of the first developing ring 81 is 85% of the inner diameter of the inlet 51.

[0097] In addition, the guide portion 13 can be provided in other shapes in addition to the semi-spherical structure, such as a conical shape. Moreover, the guide portion 13 can be composed of a plurality of guide strips. The structure is not shown in the figure. The first ends of the plurality of guide strips are connected to the catheter 10, the second ends of the plurality of guide strips extend towards the axis of the catheter 10, and the second ends of the plurality of guide strips are bent to form the guide surface 53, so as to ensure that the first developing ring 81 can be retrieved into the catheter 10.

[0098] It should be further understood that the guide portion 13 is a high polymer member 50 and is in a semi-spherical structure. Meanwhile, a plurality of communication holes 52 are formed on the guide portion 13 and are arranged around the axis of the pipe body 11. The communication holes 52 are arranged in a carved-out hollow structure, so that under the action of an external force, the communication holes 52 will deform, thereby causing the guide portion 13 to deform and enabling the umbrella protection assembly 80 to pass through the inlet 51.

[0099] Specifically, when the guide part 13 and the pipe body 11 are integrally formed, a Tip head with a hollow structure is arranged at the distal end of the catheter 10, the inner diameter of the Tip head is 0.12mm-0.22mm, the bending radius of the distal end of the Tip head is 0.4mm-0.6mm, and the bending part is engraved with a hollow pattern by laser. Optionally, the pattern shape is designed as a polygon, of course, in addition to this, the pattern shape can also be a quadrilateral, a pentagon, or other shape structures. The embodiment is described as a quadrilateral. Through the diamond-shaped hollow pattern structure, the hardness of the Tip head is reduced.

[0100] In the recovery process, by pulling the protection umbrella assembly 80, the first developing ring 81 at the proximal end of the protection umbrella assembly 80 extrudes the Tip head, so that the Tip head is deformed, the diameter of the inlet 51 of the Tip is increased, and the protection umbrella assembly 80 smoothly enters the catheter 10. At the same time, the Tip head is designed as a circular arc structure, i.e., a round corner structure, which can play a guiding role in the withdrawal process, so that the protection umbrella is more easily entered into the delivery catheter 100, thereby solving the problem that the delivery rod 61 and the delivery catheter 100 are not on the same center and are stuck, avoiding repeated recovery operations in the surgical process, reducing the operation time to reduce the risk of excessive recovery causing vasospasm of the blood vessel 2000 and other intraoperative risks. At the same time, during the process of the protection umbrella assembly 80 being received into the catheter 10, the Tip head is extruded, the four hollow holes are smaller, which can prevent the thrombus in the catheter 10 from flowing to the distal end of the blood vessel 2000 again, effectively preventing the distal end of the blood vessel 2000 from being blocked to cause stroke.

[0101] The second aspect of the present application also proposes a distal protection system 1000, which comprises the delivery catheter 100 described in the present application. Compared with the prior art, the distal protection system 1000 proposed in the present application has the technical advantages of the delivery catheter 100 described above, which will not be repeated here.

[0102] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A delivery catheter for delivering a distal protection device, characterized by, The delivery catheter comprises a tube body and a guide part, the guide part is arranged at the distal end of the tube body, the guide part has a delivery channel for the distal end protection device to pass through, and an end face of an end of the guide part away from the tube body is provided with a guide surface; The delivery channel is coaxially arranged with the tube body, the delivery channel has a first state and a second state which can be switched, in the first state, the delivery channel has a first inner diameter, in the second state, the delivery channel has a second inner diameter, the first inner diameter is smaller than the second inner diameter and smaller than the inner diameter of the tube body.

2. The delivery catheter of claim 1, wherein, Along the axial direction of the tube body, the guide part has a first cavity and a second cavity arranged in sequence, the second cavity, the first cavity and the tube body are sequentially communicated, the first cavity and the second cavity are coaxially arranged, and the inner diameter of the second cavity is smaller than the inner diameter of the first cavity, and the second cavity is formed with the first inner diameter and the second inner diameter.

3. The delivery catheter of claim 2, wherein, The inner diameter of the second cavity gradually decreases and then gradually increases along a first direction, and the first direction is a direction in which the proximal end of the tube body faces the distal end of the tube body.

4. The delivery catheter of claim 2, wherein, The guide part has a third cavity, and the third cavity is annularly arranged outside the second cavity.

5. The delivery catheter of claim 4, wherein, The guide part has an outer layer mesh tube and an inner layer mesh tube, and the outer layer mesh tube and the inner layer mesh tube are connected and form the first cavity, the second cavity and the third cavity.

6. The delivery catheter of claim 1, wherein, The guide part is a metal woven part.

7. The delivery catheter of claim 1, wherein, The guide part and the tube body are an integral part, the outer diameter of the guide part gradually decreases along a first direction, the first direction is a direction in which the proximal end of the tube body faces the distal end of the tube body, and the inner diameter of the guide part is greater than the outer diameter of the distal end protection device.

8. The delivery catheter of claim 1, wherein, The guide part is a high polymer part, and a plurality of communication holes are arranged on the guide part and are arranged around the axial line of the tube body.

9. The delivery catheter of any of claims 1-8, wherein, The distal end of the tube body is provided with a developing part, and along the axial direction of the tube body, the developing part is arranged in a spaced manner with the guide part.

10. A remote protection system, characterized by The distal end protection system comprises the delivery catheter according to any one of claims 1-9.

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