CN113018646A

Movatterモバイル変換

Info

Publication number: CN113018646A
Application number: CN201911334449.0A
Authority: CN
Inventors: 寸雨曦; 刘云云; 林恒; 刘玉梅
Original assignee: Microport Neurotech Shanghai Co Ltd
Current assignee: Microport Neurotech Shanghai Co Ltd
Priority date: 2019-12-23
Filing date: 2019-12-23
Publication date: 2021-06-25

Abstract

The invention provides a flow-resisting catheter, which comprises an inner catheter, an outer catheter and a flow-resisting element, wherein one end of the flow-resisting element is connected with the periphery of the inner catheter, and the other end of the flow-resisting element is connected with the far end of the outer catheter; the flow-obstructing element expands as the outer catheter moves in a direction toward the distal end of the inner catheter; and the flow-impeding element contracts when the outer catheter is moved in a direction away from the distal end of the inner catheter. By the configuration, the expansion of the flow resisting element can be controlled by controlling the advance and retreat of the outer catheter or the inner catheter, the configuration conversion time is short, the positioning can be repeated in the operation process, and the operation is simple, convenient and time-saving; in addition, the flow resisting element blocks the blood flow through the expansion with controllable amplitude, so that the stimulation to the cerebral vessel wall is low, and the problem of easy rupture caused by the adoption of a balloon can be avoided; in addition, when the flow resisting element contracts, the thickness of the flow resisting element is thinner, so that the inner diameter of the flow resisting element can be increased on the premise of controlling the outer diameter of the flow resisting catheter, and the flow resisting catheter is suitable for larger thrombus or instruments.

Description

Flow choking catheter

Technical Field

The invention relates to the technical field of medical instruments, in particular to a flow blocking catheter.

Background

Cerebral apoplexy, mainly caused by thrombus in cerebral vessels, is a common disease seriously threatening human health, is the third leading cause of death in the world today, and is also the disease causing the first cause of long-term disability of adults. At present, in clinical practice, thrombus is usually removed by using a therapeutic method of directly sucking thrombus by using an aspiration catheter or taking thrombus by using a stent for assisting thrombus removal, so that the recanalization of blood vessels is realized. After the suction catheter reaches the thrombus position along the blood vessel, negative pressure is applied to the near end, the thrombus is sucked into the catheter or adsorbed in the catheter opening and slowly dragged into the catheter, so that the blood vessel can obtain the blood flow power again; the stent thrombus extractor needs to cross the thrombus position, catches the thrombus by the stent meshes, retracts into the support catheter to enable the blood vessel to be communicated, and retracts into the support catheter together with the stent and the captured thrombus to enter the guide catheter after the stent retracts into the support catheter. However, in the process of embolectomy, because of the impact of proximal blood flow, thrombus often falls off and flows to a distal blood vessel, or after emboli are successfully captured, in the process of operating an aspiration catheter or an embolectomy stent to input an interventional therapy apparatus (a guide catheter or a support catheter), the broken emboli flow to the distal end of the blood vessel to form secondary occlusion, so that operation failure is caused, and the life of a patient is threatened in severe cases. For example, the myocardial necrosis rate caused by PCI percutaneous coronary intervention is as high as 16% -39%, and most of the reasons are caused by the escape of emboli from distal blood vessels during the interventional operation. In order to solve the problem caused by thrombus rupture in interventional therapy, a balloon guide catheter is usually used in the prior art to temporarily block blood flow to assist thrombus removal operation.

Generally, in the operation process, after the balloon guide catheter assists the embolectomy instrument to reach a target position (a suction catheter or a support catheter reaches the target position through an inner cavity of the balloon guide catheter), contrast solution is injected to enable the balloon to be expanded, so that the balloon can be attached to a blood vessel wall, and blood flow is temporarily blocked; after the thrombus enters the inner cavity of the suction catheter or the support catheter, the balloon guide catheter is retracted through the contraction of the balloon, and the thrombus is taken out of the human body to achieve the effect of blood flow reconstruction.

However, in the existing balloon guiding catheter products, the balloon is generally installed outside the outer catheter, and because the balloon has a certain thickness, in order to ensure that the catheter can be smoothly pushed in the blood vessel, the outer diameter of the catheter needs to be controlled to be not too large, so that the inner diameter of the catheter is too small to be adapted to a suction catheter or a support catheter with a larger lumen, and therefore, a larger thrombus cannot be treated. Meanwhile, for the balloon guide catheter, the balloon needs to be inflated with developing solution or other liquid to swell, so that the balloon can stick to the blood vessel wall to achieve the effect of blocking the blood flow, therefore, a certain time is needed for completely blocking the blood flow by using the balloon, and the contrast solution is pumped back to withdraw the balloon guide catheter, so that when the operation time is prolonged, tissue ischemia and even necrosis are caused due to overlong blood flow blocking time, and the risk that the blood vessel is damaged due to overlarge balloon filling or rupture can be brought. More importantly, in the operation process, if the balloon is inflated in an improper position, the balloon can be inflated again after the developing solution is completely discharged, a large amount of time is consumed, and the risk of balloon rupture is increased due to repeated inflation, so that secondary injury is caused to the blood vessel. In addition, the pressure caused by balloon filling is easy to stimulate the wall of cerebral vessels, thereby causing various complications in the operation process. The defects limit the auxiliary effect of the balloon in the embolectomy, and the difficulty of the embolectomy is improved, so that great risk is brought to the patient.

Disclosure of Invention

The invention aims to provide a flow-resisting catheter, which aims to solve the problems of slow flow resistance, low safety and reliability, poor repeatability, small catheter inner cavity and the like caused by adopting a saccule to resist flow in the existing guide catheter.

To solve the above technical problem, the present invention provides a flow-obstructing catheter, comprising:

an inner conduit;

the outer catheter is movably sleeved outside the inner catheter; and

one end of the flow resisting element is connected with the periphery of the inner catheter, and the other end of the flow resisting element is connected with the far end of the outer catheter; the flow-obstructing element is configured to expand when the outer catheter moves in a direction toward the distal end of the inner catheter; the flow-impeding element contracts when the outer catheter is moved in a direction away from the distal end of the inner catheter.

Optionally, in the flow blocking catheter, the flow blocking element includes a support frame, two ends of the support frame are respectively connected to the inner catheter and the outer catheter, and the support frame is configured to expand when subjected to an axial pressure and contract when subjected to an axial tension.

Optionally, in the flow-impeding conduit, the flow-impeding element further comprises a flow-impeding membrane, the flow-impeding membrane being attached to the scaffold.

Optionally, in the catheter, the distal end of the inner catheter includes an enlarged portion having a larger outer circumference than other portions of the inner catheter, and the obstructing element has one end connected to the enlarged portion and the other end connected to the distal end of the outer catheter.

Optionally, in the flow blocking catheter, the enlarged portion has a peripheral dimension that matches a peripheral dimension of the outer catheter.

Optionally, in the flow-blocking duct, the flow-blocking element comprises an equal-diameter section, the outer circumferential dimensions of which in the axial direction are the same when the flow-blocking element is expanded.

Optionally, in the flow-blocking conduit, the flow-blocking conduit further comprises a control valve to drive relative movement between the outer conduit and the outer conduit.

Optionally, in the flow blocking catheter, the control valve includes a control valve body and a control slider connected with each other, the control slider is configured to be slidable in the axial direction, the control valve body is connected with the proximal end of the inner catheter, and the control slider is connected with the proximal end of the outer catheter; or the control valve body is connected with the proximal end of the outer catheter, and the control slider is connected with the proximal end of the inner catheter.

Optionally, in the flow blocking duct, the inner duct and/or the outer duct is a single-layer tube made of a polymer material.

Optionally, in the flow blocking conduit, the inner conduit and/or the outer conduit comprises at least a two-layer structure, wherein the first and/or second layer from the inside to the outside is a polymer layer.

Optionally, in the catheter for blocking flow, the inner catheter and/or the outer catheter comprise at least two layers, and a second layer from inside to outside in the inner catheter and/or the outer catheter is one or a combination of more than two of a braided mesh structure, a coil and a cut metal tube.

Optionally, in the flow blocking conduit, the inner conduit and the outer conduit each comprise a three-layer structure.

Optionally, in the flow blocking catheter, the inner catheter comprises a first visualization ring located at a distal end of the inner catheter.

Optionally, in the flow blocking duct, the inner duct further includes a second developing ring, and the second developing ring is located on the inner duct at a position corresponding to a connection point of the flow blocking element and the inner duct.

Optionally, in the flow blocking duct, the outer duct further includes a third developing ring, and the third developing ring is located on the outer duct at a position corresponding to a connection point of the flow blocking element and the outer duct.

Optionally, in the flow-impeding catheter, the flow-impeding element comprises at least one of a mesh structure, an open loop structure, and a helical structure, the flow-impeding element being made by braiding, winding, or cutting.

Optionally, in the flow-obstructing catheter, the mesh structure is woven by 1 to 64 wires, the wires are selected from at least one of a plain wire, a developing wire and a composite wire, the plain wire is selected from at least one of a nickel-titanium alloy, a cobalt-chromium alloy, stainless steel and a polymer, the developing wire is selected from at least one of a developing metal, an alloy of a developing metal and a polymer material added with a developer, and the composite wire is formed by compounding a developing core wire and a plain wire.

In summary, the flow-blocking catheter provided by the present invention comprises an inner catheter, an outer catheter and a flow-blocking element, wherein one end of the flow-blocking element is connected to the outer circumference of the inner catheter, and the other end is connected to the distal end of the outer catheter; the flow-obstructing element expands as the outer catheter moves in a direction toward the distal end of the inner catheter; and the flow-impeding element contracts when the outer catheter is moved in a direction away from the distal end of the inner catheter. By the configuration, the expansion of the flow resisting element can be controlled by controlling the advance and retreat of the outer catheter or the inner catheter, the configuration conversion time is short, the positioning can be repeated in the operation process, and the operation is simple, convenient and time-saving; in addition, the flow resisting element blocks the blood flow through the expansion with controllable amplitude, so that the stimulation to the cerebral vessel wall is low, and the problem of easy rupture caused by the adoption of a balloon can be avoided; in addition, when the flow resisting element contracts, the thickness of the flow resisting element is thinner, so that the inner diameter of the flow resisting element can be increased on the premise of controlling the outer diameter of the flow resisting catheter, and the flow resisting catheter is suitable for larger thrombus or instruments.

Drawings

It will be appreciated by those skilled in the art that the drawings are provided for a better understanding of the invention and do not constitute any limitation to the scope of the invention. Wherein:

FIG. 1 is a schematic view of a flow blocking conduit provided in accordance with a preferred embodiment of the present invention;

FIG. 2 is a schematic illustration of a flow-blocking element provided in accordance with a preferred embodiment of the present invention in a contracted state;

FIG. 3 is a schematic illustration of a flow-impeding element provided in a preferred embodiment of the present invention in an expanded state;

FIG. 4 is a schematic illustration of a control valve provided in accordance with a preferred embodiment of the present invention;

FIG. 5 is a schematic illustration in cross-section of an inner catheter provided in accordance with a preferred embodiment of the present invention;

FIG. 6 is a schematic illustration of a cross-section of a flow blocking conduit provided in accordance with a preferred embodiment of the present invention;

FIG. 7 is a schematic view of an anti-flow catheter provided with an enlarged portion according to a preferred embodiment of the present invention;

FIG. 8 is a schematic view of a flow blocking conduit having a constant diameter section provided in accordance with a preferred embodiment of the present invention;

FIG. 9 is a schematic illustration of a braided structure of a flow-impeding element provided by a preferred embodiment of the present invention;

fig. 10a to 10g are schematic views of meshes of a support frame according to a preferred embodiment of the present invention.

In the drawings:

100-an inner catheter; 101-a first layer; 102-a second layer; 103-a third layer; 104-a binder; 110-an enlarged portion; 120-a first developer ring;

200-an outer catheter; 210-outer catheter distal end; 220-diffusion stress tube;

300-a flow-impeding element; 310-a first end; 320-a second end; 330-developing wire; 340-mesh; 350-equal diameter section;

400-a control valve; 410-a control valve body; 420-control the slide block; 430-a sliding groove; 440-a catheter hub; 500-fixing the membrane.

Detailed Description

To further clarify the objects, advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is to be noted that the drawings are in greatly simplified form and are not to scale, but are merely intended to facilitate and clarify the explanation of the embodiments of the present invention. Further, the structures illustrated in the drawings are often part of actual structures. In particular, the drawings may have different emphasis points and may sometimes be scaled differently.

As used in this specification, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise, the term "proximal" generally being the end near the operator and the term "distal" generally being the end near the lesion in the patient. As used in this specification, "one end" and "the other end" and "proximal end" and "distal end" generally refer to the corresponding two parts, which include not only the end points.

The core idea of the invention is to provide a flow-resisting catheter, which solves the problems of slow flow resistance, low safety and reliability, poor repeatability, small catheter inner cavity and the like caused by adopting a balloon to resist flow in the existing guide catheter. The flow-blocking catheter includes: an inner conduit, an outer conduit, and a flow-impeding element; the outer catheter is movably sleeved outside the inner catheter; one end of the flow resisting element is connected with the periphery of the inner catheter, and the other end of the flow resisting element is connected with the far end of the outer catheter; the flow-obstructing element is configured to expand when the outer catheter moves in a direction toward the distal end of the inner catheter; the flow-impeding element contracts when the outer catheter is moved in a direction away from the distal end of the inner catheter. By the configuration, the expansion of the flow resisting element can be controlled by controlling the advance and retreat of the outer catheter or the inner catheter, the configuration conversion time is short, the blood circulation of tissues is hardly influenced, the positioning can be repeated in the operation process, and the operation is simple, convenient and time-saving; in addition, the flow resisting element blocks the blood flow through the expansion with controllable amplitude, so that the stimulation to the cerebral vessel wall is low, and the problem of easy rupture caused by the adoption of a balloon can be avoided; in addition, when the flow resisting element contracts, the thickness of the flow resisting element is thinner, so that the inner diameter of the flow resisting element can be increased on the premise of controlling the outer diameter of the flow resisting catheter, and the flow resisting catheter is suitable for larger thrombus or instruments.

The following description refers to the accompanying drawings.

As shown in fig. 1 to 3, an embodiment of the present invention provides a flow blocking catheter, which includes: aninner catheter 100, anouter catheter 200, and a flow-impedingelement 300; theouter catheter 200 is movably sleeved outside theinner catheter 100, one end (the first end 310) of theflow blocking element 300 is connected to the outer periphery of the inner catheter 100 (for example, by gluing, welding or using a fixing film), and the other end (the second end 320) is connected to the distal end (thedistal end 210 of the outer catheter 200) (for example, by gluing, welding or using a fixing film); the flow-obstructingelement 300 is configured such that, when theouter catheter 200 is moved in the distal direction of theinner catheter 100, the flow-obstructingelement 300 expands (meaning bulges radially); when theouter catheter 200 is moved away from the distal direction of the inner catheter 100 (i.e., toward the proximal direction of the inner catheter 100), the flow-impedingelement 300 contracts (i.e., radially contracts and recovers). In other embodiments, the expansion and contraction of the flow-impedingelement 300 may also be controlled by movement of theinner catheter 100 relative to theouter catheter 200. In this embodiment, thefirst end 310 of the flow-obstructingelement 300 is disposed near the distal end of theinner catheter 100 to bring the flow-obstructing location closer to the location of the embolectomy or other instrument operation, reducing the effect on the proximal vascular blood flow, and in other embodiments, thefirst end 310 of the flow-obstructingelement 300 may be disposed in the middle or near the proximal end of theinner catheter 100.

In an exemplary embodiment, theinner catheter 100 and theouter catheter 200 are preferably circular tubes, theouter catheter 200 is sleeved outside theinner catheter 100, the difference between the inner diameter of theouter catheter 200 and the outer diameter of theinner catheter 100 can be 0.0001-0.1 inches, and theouter catheter 200 is preferably a single-layer tube made of one or more materials selected from the group consisting of polyether polyamide block copolymer (PEBA or Pebax), Polyamide (PA), and Polytetrafluoroethylene (PTFE). Theinner catheter 100 comprises at least one single polymer layer of a polymer material selected from one or more of Polytetrafluoroethylene (PTFE), High Density Polyethylene (HDPE), Pebax mixed with a coefficient of friction reducing additive, and polyolefin elastomer (POE). Theinner catheter 100 preferably comprises a three-layer structure, as shown in fig. 6, of afirst layer 101, asecond layer 102, and athird layer 103, respectively, from the inside out. Wherein, the material of thethird layer 103 may be one or more of nylon elastomer (such as Pebax), nylon and Polyurethane (PU); the material of thefirst layer 101 may be one or more of Polytetrafluoroethylene (PTFE), High Density Polyethylene (HDPE), Pebax mixed with a friction coefficient reducing additive, and polyolefin elastomer (POE); thesecond layer 102 is one or a combination of two or more of a braided structure, a coil and a cut hypotube (hypotube generally refers to a medical metal tube), and the material of thesecond layer 102 may be stainless steel, nickel-titanium alloy, cobalt-chromium alloy or polymer filament. To improve the mechanical transmission properties and the anti-ovality and anti-buckling capabilities of theinner catheter 100 and to reduce the force required for theresistive element 300 recovery. It should be understood that the materials of the various layers of theinner catheter 100 are not limited to the above materials, and those skilled in the art can select other materials with similar properties according to the prior art. In an alternative embodiment, as shown in fig. 5, theinner catheter 100 comprises only two layers, from inside to outside, afirst layer 101 and asecond layer 102, wherein thefirst layer 101 is mainly a polymer layer and is made of one or more of Polytetrafluoroethylene (PTFE), High Density Polyethylene (HDPE), Pebax mixed with a friction-reducing additive, and polyolefin elastomer (POE), thesecond layer 102 is mainly a metal layer, such as one or more of a woven structure, a coil, and a cut hypotube, and thesecond layer 102 is made of stainless steel, nitinol, or cobalt-chromium alloy. Preferably, a layer ofadhesive 104 is disposed outside the polymer layer, and the adhesive 104 penetrates the metal layer (i.e., part of the adhesive 104 penetrates the meshes of the metal layer and is adhered to the outside of the metal layer), so that the metal layer and the polymer layer are firmly embedded to improve the conductive performance and the anti-elliptical capability. Of course, in other embodiments, theouter conduit 200 is not limited to a single-layer tube, and theouter conduit 200 may also include a two-layer structure, a three-layer structure, or a more-layer structure, and the specific structural configuration thereof may refer to theinner conduit 100.

Preferably, theflow blocking element 300 includes a support frame attached to both ends of the support frame connected to theinner catheter 100 and theouter catheter 200, respectively, and a flow blocking film configured to expand (i.e., expand in a radial direction) when subjected to an axial pressure and contract (i.e., contract in a radial direction) when subjected to an axial tension. In one example, the scaffold is a tubular body that is capable of being switched between a retracted state and an expanded state, it being understood that the scaffold is not limited to being switched between the retracted state and the expanded state, and in some cases, may be in an intermediate state between the retracted state and the expanded state (i.e., a semi-expanded state or a partially expanded state). The material of the support frame can be nickel-titanium alloy, 304 stainless steel, platinum-tungsten alloy, platinum-iridium alloy, cobalt-chromium alloy or developed metal, and the structure of the support frame can be obtained by winding, cutting or weaving. In this embodiment, the supporting frame comprises a plurality of mesh holes 340, and as shown in fig. 10a to 10g, the mesh holes 340 may be diamond-shaped (fig. 10a), square-shaped (fig. 10b), rectangular-shaped (fig. 10c), parallelogram-shaped (fig. 10d), polygonal-shaped (not shown), circular-shaped (fig. 10e), oval-shaped (fig. 10f), irregular-shaped (fig. 10g), and the like, and preferably diamond-shaped (fig. 10 a). The flow-blocking film can be attached to the inner surface or the outer surface of the support frame, and is preferably a polymer film, and the material of the flow-blocking film can be Polyurethane (PU), Polyethylene (PE), Expanded Polytetrafluoroethylene (EPTFE) or the like. It is to be understood that the material of the supporting frame and the flow-resisting film is not limited to the above materials, and those skilled in the art can select other materials with similar performance according to the prior art. As shown in fig. 9, in some embodiments, the supporting frame may be a mesh structure formed by weaving 1 to 64 wires, the wires include common wires and/or developing wires, and the common wires may be selected from one or more of nickel-titanium alloy, cobalt-nickel alloy, platinum-iridium alloy, platinum, gold, tungsten, and the like; the developing wire can be made of developing metals such as platinum, iridium, gold, tungsten and the like or alloys thereof, or polymer wires with developer added can be selected. The developingwire 330 improves the developing performance of theflow blocking element 300 and improves the trackability of theflow blocking element 300 in use. In other embodiments, the scaffold may also be an open-loop structure or a helical structure, or the scaffold may be composed of several of a lattice structure, an open-loop structure and a helical structure.

Referring to fig. 2 and 3, theouter catheter 200 may control the expansion of the flow-blockingelement 300 when moving along the axial direction of the inner catheter 100 (the expansion of the flow-blockingelement 300 may be understood to be the same as the expansion of the scaffold). Specifically, as shown in fig. 2, for convenience of description, a connection point of thefirst end 310 of theflow blocking element 300 and theinner catheter 100 is referred to as a first connection point, a connection point of thesecond end 320 of theflow blocking element 300 and theouter catheter 200 is referred to as a second connection point, and in an initial default state of the flow blocking catheter, a distance between the first connection point and the second connection point along the axial direction of theinner catheter 100 is the largest, and at this time, theflow blocking element 300 is in a fully retracted state, and the largest outer diameter of the flow blocking element is equivalent to the outer diameter of the outer catheter. On the basis of fig. 2, theouter catheter 200 is pushed distally such that the axial distance between the first connection point and the second connection point is reduced, and the flow-obstructingelement 300 expands radially outwards, as shown in fig. 3, which illustrates the flow-obstructingelement 300 in a fully expanded state. When the flow-obstructingelement 300 expands outward to fit the inner diameter of the vessel wall, the flow-obstructingelement 300 is attached to the vessel wall, and the blood flow is blocked because a flow-obstructing membrane is attached to the support frame of the flow-obstructingelement 300. It is to be understood that the expansion of the obstructingelement 300 is now adapted to the vessel wall and not necessarily in a fully expanded state (i.e. possibly in a semi-expanded state or in a partially expanded state), the obstructingelement 300 preferably has a compliance which is adapted to the shape of the vessel wall in the expanded state (including the fully expanded state, the semi-expanded state or the partially expanded state). So configured, some relatively weak vessel walls may be accommodated, which may reduce the pressure on the vessel wall caused by the expansion of theresistive element 300. Therefore, theflow blocking element 300 can reduce the stimulation to the cerebral vessel wall, reduce the occurrence of various complications such as vasospasm and the like in the operation process, and simultaneously thoroughly avoid the risk of secondary damage to the vessel caused by the rupture of the balloon or the balloon bonding section.

Further, after the blood flow is blocked, suction or thrombus retraction can be directly performed through the lumen of the inner catheter 100 (the lumen of theinner catheter 100 of the flow blocking catheter can also be passed through a suction catheter or a support catheter, suction of thrombus can be performed through the suction catheter, or thrombus removal can be performed through a thrombus removal stent in the support catheter). As shown in fig. 2, since the thickness of theflow blocking element 300 is smaller when in the retracted state, the ratio of the inner cavity of theinner catheter 100 in the cross section of the whole flow blocking catheter is much larger than that of the existing balloon flow blocking catheter, so that the flow blocking catheter with the same outer diameter can be adapted to medical devices such as a suction catheter, a support catheter or a stent with a larger lumen, and is suitable for treating larger thrombus, and simultaneously, the outer diameter of the whole flow blocking catheter is limited to smoothly enter a tortuous distal end blood vessel and form a smaller wound for a patient.

Further, when it is desired to change the flow blocking position to reposition or remove the flow blocking catheter, theouter catheter 200 is operable to move proximally relative to the inner catheter 100 (i.e., to withdraw the outer catheter 200) to a maximum distance between the first and second connection points along the axial direction of theinner catheter 100. On the basis of fig. 3, when theouter catheter 200 is withdrawn proximally, the state of the flow-blockingelement 300 is reversible, i.e. the flow-blockingelement 300 can be retracted until the state shown in fig. 2 is reached. The repeatable contractibility of the flow-impedingelement 300 facilitates the re-delivery positioning of the flow-impeding conduit. Therefore, the flow blocking catheter provided by the embodiment can conveniently realize repeated operation and accurate positioning, and can also conveniently withdraw the blood vessel after thrombus removal.

As shown in fig. 4, the flow blocking conduit further comprises acontrol valve 400, thecontrol valve 400 being configured to drive theouter conduit 200 to move relative to theinner conduit 100. In one embodiment, thecontrol valve 400 includes acontrol valve body 410 and acontrol slider 420, wherein thecontrol valve body 410 is provided with a slidinggroove 430 along an axial direction, and thecontrol slider 420 is matched with the slidinggroove 430 and can slide along the direction of the slidinggroove 430. Further, one end of thecontrol valve body 410 has acatheter insertion opening 440, and the proximal end of theinner catheter 100 is inserted into thecontrol valve 400 through thecatheter insertion opening 440 and fixedly connected to thecontrol valve body 410, while the proximal end of theouter catheter 200 is connected to thecontrol slider 420, for example, by gluing or snapping. With such a configuration, the sliding of theslider 420 is controlled to control the movement (e.g., withdrawing or pushing) of theouter catheter 200 relative to theinner catheter 100, and thecontrol valve 400 controls the expansion or retraction state of theflow blocking element 300, so as to simplify the operation, save the operation time, and conveniently realize the repetitive operation. Optionally, the proximal end of theouter catheter 200 includes a diffusion stressedtube 220, and the diffusion stressedtube 220 may be flared towards the proximal end, i.e. the distal end of the diffusion stressedtube 220 has the same diameter as theouter catheter 200, while the proximal end of the diffusion stressedtube 220 has a larger diameter than theouter catheter 200. With this configuration, the diameter of the portion of theouter guide pipe 200 for connection with thecontrol slider 420 is increased, and the flareddiffusive stress pipe 220 disperses the driving force of thecontrol slider 420 to theouter guide pipe 200, thereby improving the reliability of control of theouter guide pipe 200 by thecontrol slider 420. In other embodiments, the outer conduit may be connected to thecontrol valve body 410, theinner conduit 100 may be connected to thecontrol slider 420, or other direct or indirect connection methods may be used, and the present invention is not particularly limited.

Referring to fig. 8, in a preferred embodiment, theflow blocking element 300 includes aconstant diameter section 350, and when theflow blocking element 300 is expanded, theconstant diameter section 350 has the same outer circumferential dimension in the axial direction (i.e., is cylindrical). Optionally, theconstant diameter section 350 of theflow blocking element 300 is shaped into a constant diameter tubular state in an expansion state during thermoforming, and thus, when theflow blocking element 300 expands due to axial pressure, theconstant diameter section 350 expands synchronously along the axial direction, and the shape can better fit the blood vessel wall and has a better blood flow blocking effect. It should be appreciated that in some embodiments, when theflow blocking element 300 expands, theconstant diameter section 350 is not limited to synchronous expansion, but both ends expand one after another, and the outer surface of theconstant diameter section 350 is a slope (i.e., the overall shape is conical), and theconstant diameter section 350 does not reach the same shape (i.e., cylindrical) of the outer circumference dimension along the axial direction until theflow blocking element 300 is in the fully expanded state or the state of being adapted to the inner diameter of the blood vessel wall, which is not limited by the present invention.

The above description is only for the purpose of describing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention, and any variations and modifications made by those skilled in the art based on the above disclosure are within the scope of the appended claims.

Claims

1. A flow-blocking catheter, comprising:

an inner conduit;

the outer catheter is movably sleeved outside the inner catheter; and

2. The catheter of claim 1, wherein the flow-blocking element includes a cage coupled at opposite ends to the inner catheter and the outer catheter, respectively, the cage configured to expand when subjected to axial compression forces and contract when subjected to axial tension forces.

3. The choke catheter of claim 2, wherein the choke element further includes a choke membrane, the choke membrane being attached to the support scaffold.

4. The catheter of claim 1, wherein the distal end of the inner catheter includes an enlarged portion having a larger outer circumferential dimension than other portions of the inner catheter, the obstructing member having one end connected to the enlarged portion and another end connected to the distal end of the outer catheter.

5. The catheter of claim 4, wherein the enlarged portion has a peripheral dimension that matches a peripheral dimension of the outer catheter.

6. The choke catheter of claim 1, wherein the choke element includes an equal diameter section that has the same outer circumferential dimension in an axial direction when the choke element is expanded.

7. The flow-blocking conduit of claim 1, further comprising a control valve to drive relative movement between the outer conduit and the outer conduit.

8. The catheter of claim 7, wherein the control valve includes a control valve body and a control slider connected, the control slider configured to be axially slidable, the control valve body connected to the proximal end of the inner catheter, the control slider connected to the proximal end of the outer catheter; or the control valve body is connected with the proximal end of the outer catheter, and the control slider is connected with the proximal end of the inner catheter.

9. The flow-impeding conduit of claim 1, wherein the inner conduit and/or the outer conduit is a single-layer tube made of a polymeric material.

10. The flow-impeding conduit of claim 1, wherein the inner conduit and/or the outer conduit comprises at least a two-layer structure, wherein a first layer and/or a second layer from inside to outside is a polymer layer.

11. The catheter of claim 1, wherein the inner catheter and/or the outer catheter comprise at least two layers, and wherein a second layer from the inside out of the inner catheter and/or the outer catheter is one or a combination of more than two of a braided mesh structure, a coil, and a cut metal tube.

12. The flow-impeding conduit of claim 10 or 11, wherein the inner conduit and the outer conduit each comprise a three-layer structure.

13. The flow-impeding catheter of claim 1, wherein the inner catheter comprises a first visualization ring located at a distal end of the inner catheter.

14. The choke conduit of claim 13, further comprising a second developer ring positioned on the inner conduit at a location corresponding to a connection point of the choke element to the inner conduit.

15. The flow-impeding conduit of claim 13 or 14, wherein the outer conduit further comprises a third visualization ring located on the outer conduit at a position corresponding to a connection point of the flow-impeding element with the outer conduit.

16. The choke catheter of claim 1, wherein the choke element includes at least one of a mesh structure, an open loop structure, and a helical structure, the choke element being fabricated by braiding, winding, or cutting.

17. The catheter of claim 16, wherein the lattice structure is woven from 1-64 filaments, the filaments are selected from at least one of plain filaments, developing filaments, and composite filaments, the plain filaments are selected from at least one of nitinol, cobalt-chromium alloy, stainless steel, and polymer, the developing filaments are selected from at least one of developing metal, alloy of developing metal, and polymer material with developer added, and the composite filaments are formed by compounding developing core filaments and plain filaments.