CN211461707U

CN211461707U - Flow choking catheter

Info

Publication number: CN211461707U
Application number: CN201922323832.8U
Authority: CN
Inventors: 寸雨曦; 刘云云; 林冠宇; 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: 2020-09-11
Anticipated expiration: 2029-12-23

Abstract

The utility model provides a flow resisting conduit, which comprises an inner conduit, a flow resisting element and an outer conduit, wherein the flow resisting element has self-expansion property and is sleeved outside the inner conduit, and at least the near end of the flow resisting element is connected with the periphery of the inner conduit; the outer catheter is movably sleeved outside the inner catheter and used for limiting expansion of the flow resisting element. 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 utility model relates to the technical field of medical equipment, in particular to choked flow pipe.

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.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a choked flow pipe to in solving current guide tube, adopt the sacculus choked flow and bring the choked flow slow, fail safe nature low, repeatability poor and little scheduling problem of pipe inner chamber.

In order to solve the above technical problem, the utility model provides a choked flow pipe, it includes:

an inner conduit;

the flow blocking element with self-expansion performance is sleeved outside the inner catheter, and at least the near end of the flow blocking element is connected with the periphery of the inner catheter; and

the outer catheter is movably sleeved outside the inner catheter and used for limiting the expansion of the flow resisting element.

Optionally, in the catheter, the flow-impeding element comprises a scaffold, at least a proximal end of the scaffold is connected to an outer circumference of the inner catheter, and the scaffold has self-expansion properties.

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 flow-blocking duct, one end of the flow-blocking element is connected to the outer circumference of the inner duct, and the other end is a free end; or both ends of the flow blocking element are respectively connected with the periphery of the inner guide pipe.

Optionally, in the flow blocking catheter, a groove is formed in the outer periphery of the inner catheter, and the groove is matched with the flow blocking element in shape in a retracted state to accommodate the flow blocking element.

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

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, the inner catheter and/or the outer catheter comprise at least two layers, wherein the second layer from inside to outside comprises one or a combination of two or more of braided structure, coil, and cut hypotube.

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 fixing point of the flow blocking element to the inner duct.

Optionally, in the flow-blocking duct, one end of the flow-blocking element is connected to the outer periphery of the inner duct, and the other end of the flow-blocking element is a free end.

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-blocking 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 a developing metal, an alloy of a developing metal or a polymer material added with a developer, and the composite wire is formed by compounding a developing core wire and the plain wire.

Optionally, the flow-impeding catheter further comprises a fixation membrane fixedly attached to an exterior of the proximal end of the flow-impeding element and at least partially covering the flow-impeding element and a portion of the inner catheter.

To sum up, the utility model provides a choked flow pipe includes inner catheter, choked flow component and outer catheter, choked flow component have from expanding nature, its cover is located the outside of inner catheter, and choked flow component's at least near-end with the periphery of inner catheter is connected; the outer catheter is movably sleeved outside the inner catheter and used for limiting expansion of the flow resisting element. 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

Those skilled in the art will appreciate that the drawings are provided for a better understanding of the invention and do not constitute any limitation on the scope of the invention. Wherein:

fig. 1 is a schematic view of a choke conduit provided in a preferred embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of an inner catheter according to a preferred embodiment of the present invention;

FIG. 3 is an expanded schematic view of a flow blocking element provided in accordance with a preferred embodiment of the present invention;

fig. 4 is a schematic view of a control valve according to a preferred embodiment of the present invention;

fig. 5 is a schematic cross-sectional view of a flow-impeding conduit provided in accordance with a preferred embodiment of the present invention;

fig. 6 is a schematic view of a notched choke conduit according to a preferred embodiment of the present invention;

fig. 7 is a schematic view of a choke catheter provided with a fixation membrane according to a preferred embodiment of the present invention;

fig. 8 is a schematic view of the fixed connection of the two ends of the flow resisting element to the inner conduit respectively according to a preferred embodiment of the present invention;

fig. 9 is a schematic view of a weave structure of a flow blocking element according to 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-a groove; 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;

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 make the objects, advantages and features of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments. It is to be noted that the drawings are in simplified form and are not to scale, but rather are provided for the purpose of facilitating and distinctly claiming 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 utility model is to provide a choked flow pipe to in solving current guide tube, adopt the sacculus choked flow and bring the choked flow slow, fail safe nature low, repeatability poor and little scheduling problem of pipe inner chamber. The flow-blocking catheter includes: the flow blocking element has self-expansion performance, is sleeved outside the inner catheter, and at least the near end of the flow blocking element is connected with the periphery of the inner catheter; the outer catheter is movably sleeved outside the inner catheter and used for limiting expansion of the flow resisting element. 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.

Referring to fig. 1 to 10g, wherein, fig. 1 is a schematic view of a choke catheter provided in a preferred embodiment of the present invention, fig. 2 is a schematic view of a cross section of an inner catheter provided in a preferred embodiment of the present invention, fig. 3 is a schematic view of a choke element provided in a preferred embodiment of the present invention after expansion, fig. 4 is a schematic view of a control valve provided in a preferred embodiment of the present invention, fig. 5 is a schematic view of a cross section of a choke catheter provided in a preferred embodiment of the present invention, fig. 6 is a schematic view of a choke catheter provided with a groove according to a preferred embodiment of the present invention, fig. 7 is a schematic view of a choke catheter provided with a fixed film according to a preferred embodiment of the present invention, fig. 8 is a schematic view of fixedly connecting both ends of a choke element respectively with an inner catheter provided in a preferred embodiment of the present invention, fig. 9 is a schematic view of a braided structure of a choke element provided in 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.

As shown in fig. 1 and 2, the first embodiment provides a flow blocking catheter, which includes: an inner catheter 100, a flow-impeding element 300, and an outer catheter 200; the flow-blocking element 300 has self-expanding properties, the flow-blocking element 300 is sleeved outside the inner catheter 100, and at least the proximal end (the first end 310) of the flow-blocking element 300 is connected to the outer circumference of the inner catheter 100 (e.g., by gluing, welding, or using a fixing film). The outer catheter 200 is movably sleeved outside the inner catheter 100 to limit the expansion of the flow blocking element 300. In some embodiments, the flow-blocking element 300 is configured such that, when the outer catheter 200 is moved in the proximal direction of the inner catheter 100, the flow-blocking element 300 is released from its restriction, and the flow-blocking element 300 expands (meaning expands radially) due to its self-expanding characteristic; the outer catheter 200 is moved toward the distal end of the inner catheter 100, so that the expansion of the flow blocking element 300 is restricted, and the flow blocking element 300 is contracted (i.e., restored by contraction in the radial direction). In other embodiments, the expansion and contraction of the flow-impeding element 300 may also be controlled by movement of the inner catheter 100 relative to the outer catheter 200. In this embodiment, the first end 310 of the flow-obstructing element 300 is disposed near the distal end of the inner 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, the first end 310 of the flow-obstructing element 300 may be disposed in the middle or near the proximal end of the inner catheter 100.

In an exemplary embodiment, the inner catheter 100 and the outer catheter 200 are preferably circular tubes, the outer catheter 200 is sleeved outside the inner catheter 100, the difference between the inner diameter of the outer catheter 200 and the outer diameter of the inner catheter 100 can be 0.0001-0.1 inches, and the outer 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). The inner 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). The inner catheter 100 preferably comprises a three-layer structure, as shown in fig. 5, of a first layer 101, a second layer 102, and a third layer 103, respectively, from the inside out. Wherein, the material of the third layer 103 may be one or more of nylon elastomer (such as Pebax), nylon and Polyurethane (PU); the material of the first 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); the second 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 the second 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 the inner catheter 100 and to reduce the force required for the resistive element 300 recovery. It should be understood that the materials of the various layers of the inner 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. 2, the inner catheter 100 comprises only two layers, from inside to outside, a first layer 101 and a second layer 102, wherein the first 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), the second layer 102 is mainly a metal layer, such as one or more of a woven structure, a coil, and a cut hypotube, and the second layer 102 is made of stainless steel, nitinol, or cobalt-chromium alloy. Preferably, a layer of adhesive 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, the outer conduit 200 is not limited to a single-layer tube, and the outer 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 the inner conduit 100.

Preferably, the inner catheter 100 includes a first visualization ring 120, the first visualization ring 120 being located at the distal end of the inner catheter 100. Specifically, the first visualization ring 120 may be disposed at the distal end of the second layer 102 of the inner catheter 100. More preferably, the inner catheter 100 further comprises a second visualization ring (not shown) located at a position of the inner catheter 100 corresponding to the fixation point of the flow-obstructing element 300 to the inner catheter 100. Further, when one end of the flow blocking element 300 is connected to the outer circumference of the inner guide tube 100 and the other end is a free end, the flow blocking element 300 further includes a third developing ring (not shown) at the free end of the flow blocking element 300, and the third developing ring is disposed to visually reflect the expanded state of the free end of the flow blocking element 300. Alternatively, the first developing ring 120, the second developing ring and the third developing ring may be made of, but not limited to, platinum, iridium, tantalum, noble metal alloy, etc., or may be made of a polymer material containing a developer. The three visualization rings are provided to facilitate the operator to position the inner catheter 100 or to visually reflect the expanded state of the flow blocking element 300 during the operation. It should be understood that the first visualization ring 120 is located at the distal end of the inner catheter 100, and the first visualization ring 120 is not limited to being located at the distal end of the inner catheter 100, but may be located in an area near the distal end of the inner catheter 100. Further, the above examples merely exemplify the arrangement positions of the developing rings, and do not limit that the three developing rings are necessarily arranged at the same time, and any one or any two of the developing rings may be selectively arranged by those skilled in the art according to the actual situation.

Preferably, the flow blocking element 300 comprises a scaffold, at least the proximal end of which is connected to the outer circumference of the inner catheter 100, and a flow blocking membrane, and optionally, the flow blocking element 300 further comprises a flow blocking membrane, which is attached to the scaffold. In one example, the scaffold is a tubular body that is capable of being transitioned between a retracted state and an expanded state under the constraints of the outer catheter 200, it being understood that the scaffold is not limited to being switchable only 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 have a mesh structure, and is woven by 1 to 64 wires, wherein the wires are selected from at least one of common wires, developing wires and composite wires, and the common wires may be selected from one or more of nickel-titanium alloy, cobalt-nickel alloy, stainless steel, polymer, 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 can be made of polymer wires added with developers, and the developers are the developing metals or the developing alloys; the composite wire is made by compounding a developing core wire and a common wire and has a double-layer structure, wherein the developing core wire at the inner layer is made of one or more developing metals such as platinum, iridium, gold or tungsten or alloys thereof, and the common wire at the outer layer is made of one or more materials such as nickel-titanium alloy, cobalt-nickel alloy, stainless steel, high polymer and the like. The developing wire 330 improves the developing performance of the flow blocking element 300 and improves the trackability of the flow 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. 1 and 3, the outer catheter 200 may control the expansion of the flow-blocking element 300 when moving along the axial direction of the inner catheter 100 (the expansion of the flow-blocking element 300 may be understood to be the same as the expansion of the scaffold). Specifically, in the initial default state of the flow-blocking catheter, the outer catheter distal end 210 overlies the flow-blocking element 300, limiting expansion of the flow-blocking element 300, such that the flow-blocking element 300 is in a retracted state and is crimped between the inner catheter 100 and the outer catheter 200, facilitating transport of the flow-blocking catheter in the blood vessel. When the outer catheter 200 is moved proximally relative to the inner catheter 100 (i.e., the outer catheter 200 is withdrawn), the flow-blocking element 300 is exposed from the outer catheter 200, and the flow-blocking element 300 self-expands to adhere to the blood vessel wall, thereby blocking blood flow due to the attachment of a flow-blocking membrane to the scaffold of the flow-blocking element 300. It is to be understood that the expanded configuration of the obstructing element 300 is now adapted to the vessel wall and is not necessarily in a fully expanded state (i.e. possibly in a semi-expanded state). In other cases, of course, when the outer catheter 200 is withdrawn, the distal end 210 of the outer catheter may not leave the flow-blocking element 300, such that a portion of the flow-blocking element 300 is no longer constrained by the outer catheter 200, and therefore, the portion of the flow-blocking element 300 may naturally expand and conform to the blood vessel wall, thereby blocking blood flow, i.e., the outer catheter 200 may release a portion of the flow-blocking element 300, rather than having to release all of the flow-blocking element 300 (i.e., the flow-blocking element 300 may be in a partially expanded state). The flow-impeding element 300 preferably has a certain compliance that can adapt to the morphology 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 the resistive element 300. Therefore, the flow 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 the inner 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 the flow blocking element 300 is smaller when in the retracted state, the ratio of the inner cavity of the inner 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, the outer catheter 200 may be operated to move proximally relative to the inner catheter 100 (i.e., to withdraw the outer catheter 200) until the distal end of the outer catheter 200 abuts against the flow-blocking element 300, as shown in fig. 3. And continues to push the outer catheter 200 distally until the flow-obstructing element 300 is constrained to the collapsed state. On the basis of fig. 3, when the outer catheter 200 is withdrawn proximally, the state of the flow-blocking element 300 is reversible, i.e. the flow-blocking element 300 may expand again by itself. The repeatable contractibility of the flow-impeding element 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 a control valve 400, the control valve 400 being configured to drive the outer conduit 200 to move relative to the inner conduit 100. In one embodiment, the control valve 400 includes a control valve body 410 and a control slider 420, wherein the control valve body 410 is provided with a sliding groove 430 along an axial direction, and the control slider 420 is matched with the sliding groove 430 and can slide along the direction of the sliding groove 430. Further, one end of the control valve body 410 has a catheter insertion opening 440, and the proximal end of the inner catheter 100 is inserted into the control valve 400 through the catheter insertion opening 440 and fixedly connected to the control valve body 410, while the proximal end of the outer catheter 200 is connected to the control slider 420, for example, by gluing or snapping. With such a configuration, the sliding of the slider 420 is controlled to control the movement (e.g., withdrawing or pushing) of the outer catheter 200 relative to the inner catheter 100, and the control valve 400 controls the expansion or retraction state of the flow blocking element 300, so as to simplify the operation, save the operation time, and conveniently realize the repetitive operation. Optionally, the proximal end of the outer catheter 200 includes a diffusion stressed tube 220, and the diffusion stressed tube 220 may be flared towards the proximal end, i.e. the distal end of the diffusion stressed tube 220 has the same diameter as the outer catheter 200, while the proximal end of the diffusion stressed tube 220 has a larger diameter than the outer catheter 200. With this configuration, the diameter of the portion of the outer guide pipe 200 for connection with the control slider 420 is increased, and the flared diffusive stress pipe 220 disperses the driving force of the control slider 420 to the outer guide pipe 200, thereby improving the reliability of control of the outer guide pipe 200 by the control slider 420. In other embodiments, the outer conduit may be connected to the control valve body 410, the inner conduit 100 may be connected to the control slider 420, or other direct or indirect connection methods may be adopted, which is not limited in the present invention.

Referring to fig. 6, in a preferred embodiment, the inner catheter 100 is provided with a groove 110 at the periphery, and the groove 110 matches with the shape of the flow blocking element 300 in the retracted state to accommodate the flow blocking element 300. Wherein said matching of shapes includes the case where the size of the recess 110 is the same as the size of the obstructing element 300 in the retracted state and the size of the recess 110 is larger than the size of the obstructing element 300 in the retracted state. Alternatively, the recess 110 is an annular recess around the inner catheter 100, and the obstructing element 300 may be embedded in the recess 110 when the obstructing element 300 is in the fully retracted state. Preferably, the length of the recess 110 is greater than or equal to the length of the obstructing element 300 in the retracted state, so that the obstructing element 300 can be completely accommodated in the recess 110. The provision of the grooves 110 allows the gap between the outer catheter 200 and the inner catheter 100 to be smaller, thereby further reducing the proportion of catheter in the cross-section of the entire flow-obstructing catheter and increasing the proportion of lumen of the inner catheter 100. The provision of the grooves 110 may maintain a uniform outer diameter throughout the catheter, preventing the flow-impeding element 300 from being damaged when the catheter passes through a tortuous blood vessel during transport in the blood vessel. Furthermore, the radial distances of the fixed points of the flow-obstructing element 300 and the inner catheter 100 relative to the axial direction of the inner catheter 100 are substantially equal, which facilitates the concentricity of the flow-obstructing element 300 without eccentricity when expanding, increases the adherence uniformity of the flow-obstructing element 300, and thus reduces the risk of leakage.

Referring to fig. 3, in a preferred embodiment, one end of the flow-resisting element 300 is connected to the outer circumference of the inner catheter 100, for example, by gluing or welding, and the other end of the flow-resisting element 300 is a free end. Optionally, the first end 310 (e.g., proximal end) of the flow-blocking element 300 is attached to the outer surface of the inner catheter 100, and the second end 320 (e.g., distal end) is free, such that when the flow-blocking element 300 is in the expanded state, the second end 320 is spaced from the distal end of the inner catheter 100 by a distance of 0-500mm, it being understood that the second end 320 does not extend beyond the distal end of the inner catheter 100, i.e., the flow-blocking element 300 is positioned closer to the operator than the distal end of the inner catheter 100.

As shown in fig. 7, the catheter may further include a fixing film 500, and the fixing film 500 may be attached to the outer portion of the proximal end of the flow blocking element 300, at least partially covering the flow blocking element 300 and partially covering the inner catheter 100. The fixing means of the fixing film 500 to the flow blocking element 300 and the inner catheter 100 may be gluing, heat shrinking, or the like, and the fixing capability between the flow blocking element 300 and the inner catheter 100 may be enhanced by the fixing film 500. Optionally, the fixation membrane 500 has an axial length between 1mm and 10 mm. It should be noted that, in some embodiments, the flow-resisting element 300 may be first fixed (e.g., bonded or welded) to the inner catheter 100, and then the fixing film 500 may be used as a second reinforcing fixing, further reinforcing the reliability of the fixing; in other embodiments, the flow-resisting element 300 and the inner catheter 100 may be fixed by the fixing film 500 only by a size fit or an interference fit, which is not limited by the present invention.

Referring to fig. 8, in another preferred embodiment, both ends of the flow-obstructing element 300 are respectively connected to the outer circumference of the inner catheter 100, for example, by gluing, welding or using a fixing film. Optionally, the two ends of the flow blocking element 300 are spaced at a certain distance, so configured, when the flow blocking element 300 is in the expanded state, the flow blocking element 300 is in a shuttle shape, which can better fit the blood vessel wall to achieve the effect of blocking the blood flow, and in addition, under the impact of the blood flow, the form of the flow blocking element 300 is more stable, and the risk of leakage can be further reduced. Of course, in some other embodiments, the two ends of the flow blocking element 300 may be disposed adjacent to each other or overlapped with each other, and the expansion state of the corresponding flow blocking element 300 may be an Ω shape, which may also achieve better effect, therefore, the present invention does not limit the distance between the two ends of the flow blocking element 300.

The above description is only for the preferred embodiment of the present invention and is not intended to limit the scope of the present invention, and any modification and modification made by those skilled in the art according to the above disclosure are all within the scope of the claims.

Claims

1. A flow-blocking catheter, comprising:

an inner conduit;

2. The catheter of claim 1, wherein the flow-impeding element comprises a scaffolding that is connected at least at a proximal end to a periphery of the inner catheter, and the scaffolding is self-expanding.

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 choke catheter of claim 1, wherein one end of the choke element is connected to the outer circumference of the inner catheter and the other end is a free end; or both ends of the flow blocking element are respectively connected with the periphery of the inner guide pipe.

5. The catheter of claim 1, wherein the inner catheter is provided with a groove on its outer circumference, the groove matching the shape of the obstructing element in its retracted state, for receiving the obstructing element.

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

7. The catheter of claim 6, 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.

8. 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.

9. 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.

10. The catheter of claim 1, wherein the inner catheter and/or the outer catheter comprise at least two layers of structure, wherein the second layer from the inside out comprises one or a combination of two or more of a braided structure, a coil, a cut hypotube.

11. The flow-impeding conduit of claim 9 or 10, wherein the inner conduit and the outer conduit each comprise a three-layer structure.

12. 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.

13. The choke catheter of claim 12, further comprising a second developer ring located on the inner catheter at a position corresponding to a point of attachment of the choke element to the inner catheter.

14. The choke catheter of claim 12 or 13, wherein one end of the choke element is connected to the outer circumference of the inner catheter and the other end is a free end, the choke element further comprising a third developer ring, the third developer ring being located at the free end of the choke element.

15. 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.

16. The catheter of claim 15, 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.

17. The catheter of claim 1, further comprising a securing membrane fixedly attached to an exterior of the proximal end of the obstructing element and at least partially covering the portion of the obstructing element and a portion of the inner catheter.