Recyclable arterial blood flow reducing device

Abstract

The invention provides a recoverable arterial blood flow reducing device, and relates to the technical field of interventional medical instruments, the recoverable arterial blood flow reducing device comprises a stent part, a recovery part and a pushing assembly; the stent part comprises a stent body with a wide middle part and two narrow ends, and a near-end rod body connected to the near end of the stent body; the recovery part comprises a recovery hook connected to the near-end rod body, and a sunken part is arranged on the side wall of the recovery hook; the pushing assembly comprises a long sheathing canal, a ferrule catheter arranged on the long sheathing canal in a sliding mode and a clamping piece arranged on the ferrule catheter, after the ferrule catheter is arranged on the recovery hook in a sleeving mode, the clamping piece is connected with the sunken part, and the ferrule catheter is pulled to take out the flow reducing device. After the metal elastic piece and the ferrule catheter are arranged on the recovery hook in a sleeving mode, the concave part and the clamping piece are at least connected together in the axial direction, the stent body can move towards the near end by pulling the ferrule catheter, and the problem that the flow reducing device is difficult to take out due to the fact that the stent body is difficult to connect again is conveniently solved.

Description

Technical Field

[0001] The invention belongs to the technical field of interventional medical devices, and in particular relates to a recyclable arterial blood flow reduction device. Background Art

[0002] Ischemic stroke caused by blood clots in cerebral blood vessels is a difficult-to-treat disease that seriously endangers human health and life safety. Blood clots in blood vessels will hinder the normal flow of blood in the brain, causing ischemia and hypoxia of local brain tissue. If the ischemia time is too long, nerve cells will be damaged or even die due to lack of nutrition and oxygen. The number of deaths from stroke in China each year has exceeded that of tumors and cardiovascular diseases, becoming the leading cause of death. In order to solve the above-mentioned problem of ischemic stroke deaths caused by blood clots, interventional surgical thrombectomy has become a development trend in recent years.

[0003] After the thrombus is removed through interventional surgery, blood will flow into the originally blocked blood vessels and restore blood supply to the brain. Clinically, it has been found that after the intracranial blood vessels are reopened, the recovery effect of grade 2a is better than that of grade 3. The reason is that after the blood vessels are reopened, the blood flow is reperfused and the flow rate is greater than before the reopening, which leads to capillary damage and easy formation of cerebral hematoma infarction. Therefore, a flow reduction device will be installed at the thrombus. After the operation, the flow reduction device will be left in the blood vessel. The flow reduction device allows the blood flow to maintain a small flow rate for 2-3 weeks, and the flow reduction device will be withdrawn after the blood vessel is fully recovered.

[0004] In the prior art, since the flow reducing device needs to be retained in the blood vessel for a period of time, if the withdrawal device is retained together with the flow reducing device, it will affect the patient's activities. If the withdrawal device is separated from the flow reducing device, it will be difficult to reconnect to the flow reducing device during the removal operation due to the narrow space in the blood vessel, making it difficult to remove the flow reducing device.

[0005] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Summary of the invention

[0006] The purpose of the present invention is to provide a recyclable arterial blood flow reduction device to solve the problem that it is difficult to reconnect the flow reduction device when the flow reduction device is taken out, and the flow reduction device is difficult to take out.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A retrievable arterial blood flow reduction device comprises a stent portion, a retrieving portion and a pushing component;

[0009] The stent portion includes a stent body and a proximal rod body connected to the proximal end of the stent body;

[0010] The recovery part comprises a recovery hook connected to the proximal rod body, and a recessed part is provided on the side wall of the recovery hook;

[0011] The pushing assembly includes a long sheath tube, a loop catheter slidably arranged on the long sheath tube, and a clamping piece arranged on the loop catheter. After the loop catheter is sleeved on the recovery hook, the clamping piece is connected to the recessed part, and the loop catheter is pulled to take out the flow reduction device.

[0012] Preferably, the recessed portion is a snap-fit ​​groove on the side wall of the proximal rod body, and the snap-fit ​​member includes a metal fixing ring arranged on the inner wall of the ferrule catheter and a metal spring sheet arranged on the inner wall of the metal fixing ring.

[0013] Preferably, one end of the metal spring is connected to the inner wall of the metal fixing ring, and the other end extends toward the proximal end and forms an angle with the inner wall of the ferrule catheter.

[0014] Preferably, the proximal rod body is provided with an external thread, the recovery hook is provided with an internal thread groove, and the recovery hook is threadedly connected to the proximal rod body.

[0015] Preferably, the middle portion of the bracket body is configured as an equal-diameter structure.

[0016] Preferably, the bracket portion further comprises a distal rod body disposed at the distal end of the bracket body, and the distal rod body surrounds itself to form a ring shape.

[0017] Preferably, the recovery hook is a component made of developing material.

[0018] Preferably, the inner wall of the stent body is provided with a coating, the coating covers the distal end portion of the inner wall of the stent body, and the coating is combined with the inner wall of the stent body by melting, suturing or spraying.

[0019] Preferably, the coating is a PTFE membrane or an ePTFE membrane.

[0020] Preferably, a phosphorylcholine coating is provided on the coating.

[0021] Beneficial effects:

[0022] (1) The present invention provides a recessed portion and a clamping piece. After the ferrule catheter is sleeved on the recovery hook, the recessed portion and the clamping piece are connected together at least in the axial direction. The stent body can be moved toward the proximal end by pulling the ferrule catheter, which conveniently solves the problem that it is difficult to reconnect the stent body and make it difficult to remove the flow reduction device.

[0023] (2) The present invention sets the middle part of the stent body to an equal-diameter structure so that the width of the middle part of the stent body remains unchanged, and the middle part of the stent body is parallel to the length direction of the blood vessel. The purpose of setting the equal-diameter structure is to increase the contact area between the middle part of the stent body and the inner wall of the blood vessel, thereby improving the stability of the stent body;

[0024] (3) The present invention provides a coating at the distal end of the stent body, which can block the blood flow and allow the blood to flow out from the opening at the distal end of the stent, thereby limiting the blood flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0026] Figure 1 This is a schematic diagram of the main structure of the bracket body in the embodiment of the present application, which is a hollow bracket and in a film-coated state;

[0027] Figure 2 This is a schematic diagram of the structure in which the stent body is a dense mesh stent in the embodiment of the present application and is in a film-coated state;

[0028] Figure 3 This is a structural schematic diagram of the embodiment of the present application when the bracket body is a dense mesh bracket;

[0029] Figure 4 This is a schematic diagram of the structure of an embodiment of the present invention for showing a state where a retrieval hook and a ferrule catheter are about to be connected;

[0030] Figure 5 This is a schematic diagram of the structure of an embodiment of the present invention for showing a state where the recovery hook and the loop catheter are connected;

[0031] Figure 6 This is a schematic diagram for showing the internal structure of the retrieval hook and the loop catheter according to an embodiment of the present invention;

[0032] Figure 7 It is a structural schematic diagram when the clamping member is a complete ring;

[0033] Figure 8 It is a schematic diagram of the structure of the card connector in three states;

[0034] Fig. 9 This is a schematic diagram of the structure of the clamping member in the third embodiment of the present invention when it is a rubber block.

[0035] In the figure: 1. bracket part; 11. bracket body; 12. proximal rod body; 121. external thread; 13. distal rod body; 2. recovery hook; 21. internal thread groove; 22. recessed part; 3. pushing assembly; 31. long sheath; 32. ferrule catheter; 33. clamping part; 331. metal fixing ring; 332. metal spring; 4. coating; 5. developing point. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0037] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0038] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0039] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more features.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the term "connection" should be understood in a broad sense. For example, it can be a fixed connection or a movable connection, a detachable connection or a non-detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be internal connection between two elements, indirect connection, or an interactive relationship between two elements.

[0041] In the description of the present invention, "before use" refers to the state of the recoverable arterial blood flow reduction device before use, before entering the human body, or before coming into contact with body fluids such as blood, tissue fluid, etc. in the human body, and "during use" refers to the state of the recoverable arterial blood flow reduction device after entering the human body or coming into contact with body fluids such as blood, tissue fluid, etc. in the human body.

[0042] In the description of the present invention, the "gathered state" refers to the state in which the "branch conduits" are attached to each other within a partial length range or within the entire length range.

[0043] In the description of the present invention, "proximal end" refers to the end close to the operator during surgery, and "distal end" refers to the end farthest from the operator.

[0044] In the description of the present invention, grade 0, grade 1, grade 2a, grade 2b and grade 3 are based on mTICI classification. mTICI refers to a modified cerebral infarction classification system, which is currently an indicator for evaluating the angiographic results of patients with vascular occlusive ischemic stroke after thrombectomy. It should be noted that grade 2a describes partial blood perfusion (<50%) in the distal ischemic area, and grade 3 describes complete restoration of blood perfusion in the distal ischemic area.

[0045] In the description of the present invention, "in vivo environment" refers to the environment below the epidermis of the skin where body fluids exist, such as the dermis and subcutaneous tissue, or the inside of blood vessels and organs.

[0046] The present invention will be described in detail below in conjunction with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0047] The present invention aims to solve the problem in the prior art that, since the flow reducing device needs to be retained in the blood vessel for a period of time, if the withdrawal device is retained together with the flow reducing device, it will affect the patient's activities; and if the withdrawal device is separated from the flow reducing device, it will be difficult to reconnect the withdrawal device to the flow reducing device during the removal operation due to the narrow space in the blood vessel.

[0048] The present invention discloses a recyclable arterial blood flow reduction device, comprising a stent part 1, a retrieving part and a pushing component 3;

[0049] Reference Figure 1 and Figure 2The stent portion 1 includes a stent body 11 that is wide in the middle and narrow at both ends, and a proximal rod body 12 connected to the proximal end of the stent body 11; the stent body 11 is preferably a nickel-titanium laser engraved stent to form a hollow skeleton structure. More preferably, the inner wall of the stent body 11 is coated with a film 4, and the coating 4 is in the form of hot melting, suturing or spraying. The nickel-titanium laser engraved stent adopts nickel-titanium alloy, and the nickel-titanium alloy has a shape memory function. After being released, the stent body 11 can automatically expand and abut against the inner wall of the blood vessel to achieve the fixation of the stent body 11, and can withstand blood flow erosion without displacement.

[0050] Reference Figure 3 In another embodiment of the present application, the distal end of the stent body 11 is a dense mesh stent that does not allow or only allows blood to seep out.

[0051] In a preferred embodiment, the middle portion of the stent body 11 is configured as an equal-diameter structure, and the width of the equal-diameter portion is the largest, so that the equal-diameter portion can better fit the inner wall of the blood vessel, thereby further enhancing the stability of the stent body 11.

[0052] Reference Figures 1 to 3 , the width of the stent body 11 gradually shrinks from the middle part to the two ends of the stent body 11. The two ends of the stent body 11 are open, and the middle part is unobstructed, allowing blood to flow through. The blood flows in from the proximal end of the stent body 11 and flows out from the distal end of the stent body 11. The proximal end of the stent body 11 is funnel-shaped. The purpose of this design is to reduce the contact area between the stent body 11 and the blood vessel, reduce endothelialization, and reduce recovery resistance. It should be noted that the part of the stent body 11 covered with the film 4 does not allow blood to pass through, so that the blood flow is concentrated at the distal opening and flows out. The purpose of this design is to reduce the diameter of the blood flow channel from large to small, thereby reducing the blood flow in the blood vessel after the initial recovery and protecting the blood vessel. The transition between the middle and the two ends of the stent body 11 is smooth to avoid scratching or tearing the blood vessel wall during recovery, reduce recovery resistance, and facilitate recovery.

[0053] The proximal rod 12 can be integrally formed with the stent body 11, or can be connected by welding, hot melting, etc. The proximal rod 12 is preferably made of stainless steel, which has good strength and toughness, can withstand a certain amount of tension and bending, and has little impact on the human body environment. In other embodiments of the present application, the proximal rod 12 is made of nickel-titanium alloy, which has a shape memory function. After passing through the tortuous intracranial blood vessels, it can return to the initial straight shape, which is convenient for the placement of the stent body 11, and the nickel-titanium alloy is relatively soft and has little damage to the blood vessel wall.

[0054] The recovery part includes a recovery hook 2 connected to the proximal rod body 12, and a recessed part 22 is provided on the side wall of the recovery hook 2;

[0055] Reference Figures 1 to 4The push assembly 3 includes a long sheath tube 31, a ferrule catheter 32 slidably arranged on the long sheath tube 31, and a clamping piece 33 arranged on the ferrule catheter 32. After the ferrule catheter 32 is sleeved on the recovery hook 2, the clamping piece 33 is hooked with the recovery hook 2, and the ferrule catheter 32 is pulled to remove the flow reduction device. The recessed portion 22 is formed by the side wall of the recovery hook 2 near the proximal end being recessed toward the inside of itself. In a specific embodiment, the recessed portion 22 is an annular groove arranged along the circumference of the recovery hook 2. The distal end of the recovery hook 2 is provided with a connection structure adapted to the proximal rod body 12. Specifically, the connection between the recovery hook 2 and the proximal rod body 12 can be threaded connection, buckle connection, snare connection, bonding or welding. It should be noted that in order to prevent the recovery hook 2 from causing damage to the inner wall of the blood vessel, each corner of the recovery hook 2 is provided with a smooth chamfer, and the surface of the recovery hook 2 is smooth to avoid the presence of sharp parts.

[0056] Reference Figures 1 to 5 The long sheath 31 is made of medical-grade polymer materials, such as polytetrafluoroethylene (PTFE), polyurethane (PU), etc. Polytetrafluoroethylene has excellent chemical stability, low friction coefficient and good biocompatibility. When the long sheath 31 contacts blood and human tissue, it will not cause obvious chemical reactions, nor will it be easily identified as a foreign body by the human immune system, and can flow smoothly in the blood vessels. The loop catheter 32 is inserted into the channel of the long sheath 31 by means of a sliding connection. The opening of the loop catheter 32 can be circular or elliptical. There is no limitation on the shape of the opening. It only needs to be slightly larger than the proximal end of the recovery hook 2 to allow the proximal end of the recovery hook 2 to be inserted.

[0057] Reference Figure 6 and Figure 7 The proximal end of the recovery hook 2 shrinks toward the middle to form an oblique surface. After the loop catheter 32 contacts the oblique surface, the oblique surface guides the loop catheter 32, allowing the loop catheter 32 to move along the oblique surface, thereby conveniently guiding the recovery hook 2 to the inside of the loop catheter 32. The clamping member 33 is an elastic component, preferably a spring or an elastic rubber block. After being squeezed by the recovery hook 2, it is deformed. When the clamping member 33 passes through the recessed portion 22 of the recovery hook 2, the clamping member 33 is restored, allowing the clamping member 33 to be clamped in the recessed portion 22. At this time, the loop catheter 32 is pulled, and the clamping member 33 abuts against the side wall of the recessed portion 22, transmitting the force to the recovery hook 2, and then sequentially transmitted to the proximal rod body 12 and the stent body 11, thereby achieving the pulling of the stent body 11.

[0058] Reference Figures 1 to 6, Usage process: When the blood vessel recovers its pressure resistance, it is only necessary to perform blood vessel puncture, push the long sheath tube 31 to the proximal position of the stent body 11, the loop catheter 32 first contacts the recovery hook 2, moves along the recovery hook 2, and the front end of the recovery hook 2 squeezes the clamping member 33 to deform the clamping member 33, and continues to move to allow the clamping member 33 to enter the recessed portion 22. At this time, at least in the axial direction of the blood vessel, the clamping member 33 is fixedly connected to the recessed portion 22, and the stent body 11 can be pulled by pulling the loop catheter 32. By pulling the loop catheter 32, the stent body 11 is pressed into the long sheath tube 31, and then all are recovered, which conveniently solves the problem that it is difficult to reconnect the stent body 11, resulting in difficulty in removing the flow reduction device.

[0059] In a preferred embodiment of the invention, the recessed portion 22 is a snap-fit ​​groove provided on the side wall of the proximal rod body 12, and the snap-fit ​​member 33 includes a metal fixing ring 331 provided on the inner wall of the ferrule catheter 32, and a metal spring 332 provided on the inner wall of the metal fixing ring 331, one end of the metal spring 332 is connected to the inner wall of the metal fixing ring 331, and the other end extends toward the proximal end and has an angle with the inner wall of the ferrule catheter 32; the snap-fit ​​groove covers the circumference of the side wall of the proximal rod body 12 and is annular. The metal fixing ring 331 is fixed to the inner wall of the ferrule catheter 32 by hot-melt connection or welding. The shape of the metal fixing ring 331 is adapted to the inner wall of the ferrule catheter 32, and the metal fixing ring 331 and the metal spring 332 are preferably made of stainless steel, which has both strength and toughness, can withstand a certain tension and bending, and has little effect on the internal environment of the human body. The metal spring 332 is deformed when squeezed, and recovers after entering the clamping groove, and abuts against the side wall of the clamping groove to achieve fixation along the axial direction of the blood vessel. Preferably, the angle between the metal spring 332 and the inner wall of the ferrule catheter 32 is ≤30°. The purpose of setting the angle is to provide a buffer between the recovery hook 2 and the metal spring 332, reduce the damage to the metal spring 332 caused by squeezing, and extend the service life of the metal spring 332.

[0060] Reference Figure 8 There are at least three metal spring pieces 332, and the three metal spring pieces 332 are arranged in a ring shape with equal spacing. The three metal spring pieces 332 are clamped in the recessed portion 22 to achieve fixation in the axial direction of the blood vessel.

[0061] Reference Figure 7 In another preferred embodiment, the metal spring piece 332 is a whole piece in a ring shape, and the design here makes the connection between the metal spring piece 332 and the recessed portion 22 more stable.

[0062] In another embodiment of the present application, the clamping member 33 can be an elastic rubber block, which is connected to the metal fixing ring 331 by bonding. A guiding slope is provided on the elastic rubber block, and the guiding slope has an angle consistent with the bevel of the recovery hook 2, which is used to guide the recovery hook 2 to facilitate squeezing the elastic rubber block. When the elastic rubber block is located in the recessed portion 22, it returns to its original state, and the elastic rubber block is clamped with the recessed portion 22.

[0063] The proximal rod body 12 is provided with an external thread 121, and the recovery hook 2 is provided with an internal thread groove 21, and the recovery hook 2 is threadedly connected to the proximal rod body 12. The material of the external thread 121 is consistent with that of the proximal rod body 12, and is integrally formed with the proximal rod body 12. The interior of the recovery hook 2 is provided with an internal thread groove 21 with a diameter slightly larger than that of the proximal rod body 12, and the internal thread groove 21 penetrates the recovery hook 2. The internal thread is provided on the side wall of the internal thread groove 21. When installing the proximal rod body 12 and the recovery hook 2, the internal thread groove 21 is aligned with the proximal rod body 12, and the recovery hook 2 is rotated to be threadedly connected with the proximal rod body 12. The threaded connection has strong stability and is also convenient for disassembly and cleaning.

[0064] Regarding the release operation after the stent body 11 is in place: before the stent body 11 is installed, the stent body 11 is connected to the front end of a sheath tube by threading. Specifically, the front end of the sheath tube is inserted into the internal thread groove 21 and threadedly connected to the internal thread groove 21. After the stent body 11 is installed, the sheath tube is rotated to disconnect the front end of the sheath tube from the internal thread groove 21, completing the release operation.

[0065] More preferably, the middle part of the stent body 11 is configured as an equal-diameter structure. It is understandable that the equal-diameter structure refers to the parallel state between the nickel-titanium wires in the middle part of the stent body 11, so that the width of the middle part of the stent body 11 remains unchanged, and the middle part of the stent body 11 is parallel to the length direction of the blood vessel. The purpose of setting the equal-diameter structure is to increase the contact area between the middle part of the stent body 11 and the inner wall of the blood vessel, thereby improving the stability of the stent body 11. In another embodiment of the present application, the middle part of the stent body 11 is designed as an inclined elliptical surface structure to increase the contact area between the stent body 11 and the inner wall of the blood vessel and improve stability.

[0066] In a preferred embodiment of the present invention, the stent portion 1 further comprises a distal rod 13 disposed at the distal end of the stent body 11, and the distal rod 13 surrounds itself to form a ring. The distal rod 13 is connected end to end to form a ring, and the distal rod 13 is sutured together with the distal end of the stent body 11, so that a structurally stable opening is left at the distal end of the stent body 11, thereby not blocking the blood flow. The diameter of the ring formed by the distal rod 13 is smaller than the diameter of the middle part of the stent body 11, so that the blood flow is reduced.

[0067] In a preferred embodiment of the present invention, a developing point 5 is provided on the stent body 11, the retrieval hook 2 and the ferrule catheter 32. The developing point 5 is formed by densely winding platinum-iridium wire, and the mounting method of the developing point 5 is bonding. By providing the developing point 5, it is convenient to locate the positions of the stent body 11, the retrieval hook 2, and the ferrule catheter 32 under DSA during surgery, which is convenient for the surgeon to make real-time adjustments and reduce the difficulty of surgery.

[0068] In a preferred embodiment of the present invention, the inner wall of the stent body 11 is provided with a coating 4, which covers the distal end of the inner wall of the stent body 11, and the coating 4 is combined with the inner wall of the stent body 11 by melting, suturing or spraying. The advantage of such a design is that the coating 4 can block the blood flow, allowing the blood flow to flow out of the opening at the distal end of the stent, thereby limiting the blood flow.

[0069] In the present invention, the coating 4 is a PTFE membrane or an ePTFE membrane. Both the PTFE membrane and the ePTFE membrane have excellent chemical stability, can hinder blood flow, and can limit the flow of blood when combined with the stent body 11. In the embodiment of the present application, the coating 4 can only cover the distal half of the stent body 11, or can cover the distal one-third of the stent body 11, or can completely cover the distal end of the stent body 11.

[0070] In a preferred embodiment of the present invention, when an ePTFE membrane is used, a microporous structure is provided on the membrane 4, a phosphorylcholine coating is provided on the membrane 4, and the phosphorylcholine coating covers the microporous structure. The microporous structure is a pore on the membrane 4 that does not penetrate the membrane 4. The microporous structure on the membrane 4 makes it easier for the membrane 4 to combine with the phosphorylcholine coating, and the phosphorylcholine coating makes the flow reduction device have the characteristics of biocompatibility, blood compatibility and anti-protein adsorption, which facilitates the subsequent removal of the device.

[0071] The following is a detailed description of a recyclable arterial blood flow reduction device of the present invention through specific embodiments.

[0072] Example 1

[0073] This embodiment provides a recoverable arterial blood flow reduction device, which includes a stent portion 1, a recovery portion and a pushing component 3 as shown in the figure.

[0074] The stent portion 1 includes a stent body 11 that is wide in the middle and gradually narrows at both ends. The stent body 11 is formed by laser engraving of a nickel-titanium alloy material. The distal portion of the stent body 11 preferably adopts a dense mesh stent, and the dense mesh is required to not allow blood circulation. A distal rod body 13 is sewn at the distal end of the stent body 11. The distal rod body 13 is in a ring shape with a connected tail, the purpose of which is to stabilize the distal opening structure of the stent body 11 and also to avoid completely blocking the blood flow.

[0075] The middle part of the stent body 11 is set as an equal-diameter structure. The equal-diameter part is the largest in the width of the stent body 11. The equal-diameter structure means that the nickel-titanium wires in this part are parallel to each other, and the width of this part remains unchanged. The purpose of the design here is to increase the contact area between the stent body 11 and the inner wall of the blood vessel, thereby increasing the stability of the stent body 11 and allowing the stent body 11 to withstand blood flow erosion without displacement.

[0076] The proximal end of the stent body 11 is provided with at least four nickel-titanium wires that converge toward the middle, forming a funnel shape. The proximal mesh opening of the stent body 11 is larger, allowing blood flow to pass through, and has less impact on blood flow. The funnel-shaped proximal design can reduce the contact area between the stent body 11 and the blood vessel, reduce endothelialization, and reduce recovery resistance.

[0077] The middle and both ends of the stent body 11 are rounded to avoid scratching or tearing the blood vessel wall during recovery, reduce recovery resistance, and facilitate recovery.

[0078] In this embodiment, a proximal rod body 12 is welded to the proximal end of the stent body 11. The proximal rod body 12 is preferably made of stainless steel. Stainless steel has good strength and toughness and can withstand a certain amount of tension and bending. At the same time, stainless steel material has a certain degree of corrosion resistance and has little impact on the human body environment.

[0079] The proximal rod body 12 is provided with a recovery hook 2, and the side wall of the recovery hook 2 near the proximal end is inwardly recessed to form a recessed portion 22, and the recovery hook 2 is completely recessed in the circumferential direction, so that the recessed portion 22 is a whole annular clamping groove. The recovery hook 2 and the proximal rod body 12 are connected by one of the following methods: threaded connection, snap connection, snare connection, bonding or welding.

[0080] In a preferred embodiment of the present application, an external thread 121 is provided on the outer circumferential surface of the proximal rod body 12, and an internal thread groove 21 running through the length direction of the proximal rod body 12 is provided on the recovery hook 2, and the proximal rod body 12 is threadedly connected to the recovery hook 2.

[0081] The pushing assembly 3 includes a long sheath tube 31, which is a tube with a through channel in the middle. A loop catheter 32 is slidably arranged in the middle of the long sheath tube 31, and a clamping piece 33 is arranged on the inner wall of the distal end of the loop catheter 32. After the loop catheter 32 is put on the recovery hook 2, the clamping piece 33 is hooked with the recovery hook 2, and the loop catheter 32 is pulled to take out the flow reduction device.

[0082] The long sheath 31 is made of medical grade polymer material, preferably polytetrafluoroethylene (PTFE), which has excellent chemical stability, low friction coefficient and good biocompatibility, reducing the impact on the intravascular environment. The loop catheter 32 is a tube body with an inner cavity in the middle. There is no restriction on the opening shape of the loop catheter 32, as long as it is slightly larger than the proximal end of the retrieval hook 2, so that the proximal end of the retrieval hook 2 can be inserted.

[0083] Specifically, refer to Figure 6 and Figure 7 The clamping part 33 includes a metal fixing ring 331 connected to the inner wall of the ferrule catheter 32 by hot-melt connection or welding. The metal fixing ring 331 is preferably made of stainless steel to meet the requirements of strength and toughness. A metal spring 332 is welded on the inner wall of the metal fixing ring 331. The metal spring 332 extends toward the proximal end and forms an angle of 30° with the inner wall of the ferrule catheter 32. In other embodiments of the present application, the angle between the metal spring 332 and the inner wall of the ferrule catheter 32 is 25°, 20° or 10°. The metal springs 332 are arranged on the metal fixing ring 331 in an annular shape and at equal intervals, and there are three of them.

[0084] Reference Figure 7 In a preferred embodiment, the metal spring 332 is a whole piece and is ring-shaped.

[0085] Reference Figure 4 , Figure 5 and Figure 6 The release operation is as follows: before installing the stent body 11, use a sheath tube with an external thread 121 at the distal end, insert the front end of the sheath tube into the internal thread groove 21, and connect the sheath tube to the recovery hook 2. After the stent body 11 is installed, rotate the sheath tube to disconnect the front end of the sheath tube from the internal thread groove 21, and complete the release operation.

[0086] When the blood vessel recovers its pressure resistance, it only needs to perform blood vessel puncture, push the long sheath tube 31 to the proximal position of the stent body 11, and the loop catheter 32 first contacts the recovery hook 2, and the recovery hook 2 is inserted into the loop catheter 32, so that the metal spring 332 is deformed when squeezed, enters the clamping groove and recovers, and abuts against the side wall of the clamping groove to achieve fixation along the axial direction of the blood vessel. Then, the loop catheter 32 is pulled, and the stent body 11 is pressed into the long sheath tube 31, and then all are recovered.

[0087] In a preferred embodiment of the present invention, the support body 11, the recovery hook 2 and the loop catheter 32 are all bonded with developing points 5, and the developing points 5 are formed by densely wound platinum-iridium wires. Due to its high density, the platinum-iridium alloy has a strong ability to block and absorb X-rays, and can clearly display the positions of the support body 11, the recovery hook 2, and the loop catheter 32 under DSA.

[0088] Example 2

[0089] This embodiment further describes the bracket body 11 based on the embodiment 1.

[0090] Reference Figure 1 and Figure 2 In this embodiment, the stent body 11 may be a non-dense mesh stent, and the distal end of the stent body 11 is provided with a coating 4. Specifically, the coating 4 is connected by melting, suturing or spraying.

[0091] The coating 4 is a PTFE film. The PTFE film has excellent chemical stability, can block the blood flow, and cooperates with the stent body 11 to limit the blood flow.

[0092] The coating 4 is provided with a phosphorylcholine coating, and the coating method is one of a dip coating method, a spray coating method, a spin coating method, and a chemical vapor deposition method.

[0093] In another embodiment of the present application, the coating 4 is an ePTFE membrane having a microporous structure, which is more easily combined with the phosphorylcholine coating, so that the device has the characteristics of biocompatibility, blood compatibility and anti-protein adsorption, which facilitates the subsequent removal of the device.

[0094] Example 3

[0095] The difference between this embodiment and the first embodiment lies in the clamping member 33 .

[0096] Reference Figure 4 , Figure 5 , Figure 6 and Fig. 9 The proximal end of the retrieval hook 2 contracts toward the middle to form a beveled surface. After the loop catheter 32 contacts the beveled surface, the beveled surface guides the loop catheter 32, allowing the loop catheter 32 to move along the beveled surface, thereby conveniently guiding the retrieval hook 2 into the inside of the loop catheter 32.

[0097] The clamping piece 33 is an elastic rubber block, which is connected to the metal fixing ring 331 by bonding. A guiding slope is provided on the elastic rubber block. The guiding slope has the same angle as the bevel of the recovery hook 2 and is used to guide the recovery hook 2 to facilitate squeezing the elastic rubber block. When the elastic rubber block is located in the recessed portion 22, it returns to its original state and is clamped with the recessed portion 22.

[0098] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A recyclable arterial blood flow reduction device, characterized in that: It comprises a support part (1), a recovery part and a pushing component (3); The support portion (1) comprises a support body (11) and a proximal rod (12) connected to the proximal end of the support body (11); The recovery portion comprises a recovery hook (2) connected to the proximal rod body (12), and a recessed portion (22) is provided on the side wall of the recovery hook (2); The pushing assembly (3) comprises a long sheath tube (31), a loop catheter (32) slidably arranged in the long sheath tube (31), and a clamping piece (33) arranged on the loop catheter (32). After the loop catheter (32) is sleeved on the recovery hook (2), the clamping piece (33) is connected to the recessed portion (22), and the loop catheter (32) is pulled to remove the flow reduction device.

2. A recyclable arterial blood flow reduction device according to claim 1, characterized in that: The recessed portion (22) is a clamping groove on the side wall of the proximal rod body (12), and the clamping member (33) comprises a metal fixing ring (331) arranged on the inner wall of the ferrule catheter (32), and a metal spring sheet (332) arranged on the inner wall of the metal fixing ring (331).

3. A recyclable arterial blood flow reduction device according to claim 2, characterized in that: One end of the metal spring sheet (332) is connected to the inner wall of the metal fixing ring (331), and the other end extends toward the proximal end and forms an angle with the inner wall of the ferrule catheter (32).

4. A recyclable arterial blood flow reduction device according to claim 1, characterized in that: The proximal rod body (12) is provided with an external thread (121), the recovery hook (2) is provided with an internal thread groove (21), and the recovery hook (2) is threadedly connected to the proximal rod body (12).

5. A recyclable arterial blood flow reduction device according to claim 1, characterized in that: The middle part of the support body (11) is arranged as an equal-diameter structure.

6. A recyclable arterial blood flow reduction device according to claim 5, characterized in that: The bracket part (1) further comprises a distal rod body (13) arranged at the distal end of the bracket body (11), and the distal rod body (13) surrounds itself to form a ring shape.

7. A recyclable arterial blood flow reduction device according to claim 1, characterized in that: The support body (11), the recovery hook (2) and the ferrule catheter (32) are all provided with developing points (5).

8. A recyclable arterial blood flow reduction device according to any one of claims 1 to 7, characterized in that: The inner wall of the stent body (11) is provided with a coating (4), and the coating (4) covers the distal end portion of the inner wall of the stent body (11). The coating (4) is combined with the inner wall of the stent body (11) by melting, suturing or spraying.

9. A recyclable arterial blood flow reduction device according to claim 8, characterized in that: The coating (4) is a PTFE film or an ePTFE film.

10. A recyclable arterial blood flow reduction device according to claim 9, characterized in that: The coating (4) is provided with a phosphorylcholine coating.

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