A controllable detachable balloon catheter

Abstract

The present invention relates to the technical field of medical devices, and particularly to a controllable detachment balloon catheter, which comprises a microcatheter and an outer sheath arranged coaxially, and the outer sheath is movably arranged relative to the microcatheter in the axial direction; a catheter hub, connected to the proximal ends of the microcatheter and the outer sheath, the catheter hub comprising a liquid filling cavity communicated with the proximal end of the microcatheter and a filling cavity, the filling cavity being communicated with the gap between the outer sheath and the microcatheter, and a filling balloon communicated with the gap being arranged at the distal end of the outer sheath; the microcatheter comprises a body section and a detachment section, the proximal end of the detachment section is detachably connected to the distal end of the body section, and the inner cavity of the detachment section is communicated with the inner cavity of the body section to form the microcatheter; a detachment structure is formed between the distal end of the outer sheath and the proximal end of the detachment section, and the detachment structure is configured such that when the outer sheath moves relative to the microcatheter towards the proximal end until the detachment section is located outside the outer sheath, the body section is separated from the detachment section. Through the above arrangement, the detachment of the microcatheter of the present invention is controllable, the blood vessel is not damaged and the embolizing agent will not escape.

Description

Technical Field

[0001] The invention relates to the technical field of medical devices, and in particular to a controllable release balloon catheter. Background Art

[0002] In the treatment of neurovascular diseases, in addition to surgical resection and radiotherapy, interventional therapy has become an irreplaceable treatment method. The embolic materials and embolic catheters used for different diseases are different, but the use of liquid embolic agents and embolic microcatheter technology is currently considered to be the safest and most effective method for treating cerebral arteriovenous malformations and dural venous fistulas.

[0003] The current intravascular interventional embolization technology is to obtain vascular access through arterial or venous puncture, use guidewires, catheters and other instruments to enter the deformed lesion site, and then inject liquid embolic agents through the embolization microcatheter to block the lesion site, thereby achieving the purpose of treatment. During the embolization process, a small amount of embolic agent backflow is usually required to block the proximal blood supply artery to ensure that the embolic agent can better diffuse to the target location. However, there are risks in the backflow of embolic agents, mainly the following two points: the backflow of embolic agents into the blood supply artery of normal brain tissue causes cerebral infarction; the microcatheter is entangled, making it difficult or even impossible to remove the tube. Due to concerns about the risk of reflux, insufficient reflux often occurs, making it impossible for the embolic agent to fully diffuse and achieve the desired effect.

[0004] In the related art, the embolic agents used for intravascular interventional embolization therapy are mostly liquid mixtures. The embolic agents are fluid and will form a colloid mold in a relatively short period of time. Therefore, when the embolic agents are injected through a microcatheter, the embolic agents are prone to diffuse along the microcatheter. Due to the characteristic that the embolic agents form a colloid mold in a relatively short period of time, the microcatheter is often clamped in the colloid of the mold, making it difficult or even impossible to withdraw the tube. The microcatheter technology with a detachable head end currently used in clinical practice can reduce the shortcomings of the existing technology to a certain extent, but it cannot control the backflow of the embolic agent. Once the embolic agent backflow exceeds its release point, it will still cause the microcatheter to be stuck, making it difficult or even impossible to withdraw the tube. If the tube is forcibly withdrawn, it may cause secondary damage to the diseased blood vessels or bring out the embolic agent. Summary of the invention

[0005] In view of at least one of the above technical problems, the present invention provides a controllable detachable balloon catheter, which adopts structural improvement to improve the safety of catheter removal.

[0006] According to one aspect of the present invention, there is provided a controllable detachable balloon catheter, comprising:

[0007] A microcatheter and an outer sleeve are coaxially arranged, wherein the outer sleeve is movably arranged relative to the microcatheter in the axial direction;

[0008] A catheter seat is connected to the proximal ends of the micro - catheter and the outer catheter. The catheter seat includes a liquid - filling cavity communicating with the proximal end of the micro - catheter and a filling cavity. The filling cavity is in communication with the gap between the outer catheter and the micro - catheter. A filling balloon communicating with this gap is provided at the distal end of the outer catheter.

[0009] The micro - catheter includes a body section and a detachable section. The proximal end of the detachable section is detachably connected to the distal end of the body section, and the inner cavity of the detachable section communicates with the inner cavity of the body section to form the micro - catheter.

[0010] Wherein, a detaching structure is formed between the distal end of the outer catheter and the proximal end of the detachable section. The detaching structure is configured such that when the outer catheter moves proximally relative to the micro - catheter until the detachable section is outside the outer catheter, the body section is separated from the detachable section.

[0011] In some embodiments of the present invention, the diameter of the detachable section is smaller than that of the body section, and the proximal end of the detachable section is flared.

[0012] In some embodiments of the present invention, the detaching structure includes an inner boss provided at the distal end of the outer catheter and an outer boss provided at the proximal end of the detachable section. The outer boss is proximal to the inner boss before detachment, and the inner boss and the outer boss form an interleaved sealing structure in the thickness direction of the tube wall.

[0013] In some embodiments of the present invention, the outer boss is an annular structure, and the inner boss is intermittently provided in the circumferential direction.

[0014] In some embodiments of the present invention, the opposing surfaces of the inner boss and the outer boss are parallel inclined surfaces, and the outer ends of the inclined surfaces are close to the catheter seat.

[0015] In some embodiments of the present invention, the proximal end of the detachable section is in close butt - joint with the distal end of the body section before detachment, and a first sealing layer is coated on the outside of the butt - joint.

[0016] In some embodiments of the present invention, the distal end of the outer catheter is in a necked - down shape, and a second sealing layer is coated on the outer region where the distal end of the outer catheter contacts the detachable section.

[0017] In some embodiments of the present invention, the proximal end of the outer catheter has a telescopic section made of a flexible polymer material.

[0018] In some embodiments of the present invention, a pull - ring is further provided at the distal end of the telescopic section for controlling the movement of the outer catheter.

[0019] In some embodiments of the present invention, a radiopaque ring is provided in both the distal end of the detachable section and the inner boss and the outer boss.

[0020] The beneficial effects of the present invention are as follows: Through the release structure formed by the distal end of the outer sheath and the release section of the microcatheter, after the microcatheter completes the occlusion of the diseased blood vessel, it remains in the diseased blood vessel by means of release of the release section, and the release is achieved through the relative movement of the outer sheath. Compared with the prior art, the release timing of the microcatheter is precisely controllable and has high safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a schematic structural diagram of the controllable release balloon catheter in the embodiment of the present invention;

[0023] Figure 2 It is a partial enlarged structural diagram of the release structure in the embodiment of the present invention;

[0024] Figure 3 It is a structural diagram of the release structure during expansion in the embodiment of the present invention;

[0025] Figure 4 It is a structural diagram of the release mechanism when the outer convex platform passes through the inner convex platform in the embodiment of the present invention;

[0026] Figure 5 It is a structural diagram of the release mechanism when the release is completed in the embodiment of the present invention;

[0027] Figure 6 It is a schematic structural diagram of the connection between the catheter seat and the outer sheath in the embodiment of the present invention.

[0028] Reference numerals: 1, microcatheter; 11, body section; 12, release section; 2, outer sheath; 21, inflation balloon; 22, telescopic section; 23, pull ring; 3, catheter seat; 31, liquid filling cavity; 32, inflation cavity; 4, release structure; 41, inner convex platform; 42, outer convex platform; 43, first sealing layer; 44, second sealing layer; 5, radiopaque ring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0030] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0032] The detachable end in the prior art cannot control the backflow of the embolic agent, and the detachable catheter head end adopts a degradable coating material, which makes the catheter head end uncontrollable when detached, and there is a great risk of use. For example, premature detachment may lead to blockage of normal blood vessels. If the detachment time is long, the operation time will be prolonged. In addition, the detachable catheter adopts a mechanical structure, and the catheter head end is detached by adjusting the pulling force, which poses a risk of catheter use. If the pushing or withdrawal exceeds the specified pulling force during the process of the catheter being in place, the catheter may be detached prematurely, resulting in blockage of normal blood vessels. If the catheter is detached after embolism, excessive pulling force may cause secondary damage to the diseased blood vessels or bring out the embolic agent. In order to solve the above problems, the present invention arranges an inflatable balloon at the distal end of the catheter, which, when the embolic agent is normally injected, plays a role in blocking the proximal blood flow and preventing the embolic agent from flowing back into the normal blood supply artery. After the embolic agent is completely embolized, in order to allow the catheter to be better withdrawn, the tip of the microcatheter close to the balloon is designed as a detachable structure, so that the catheter completely fixed in the embolic agent can be released, thereby withdrawing the catheter; the following part of the embodiment of the present application will exemplarily illustrate the inventive concept of the present application.

[0033] like Figures 1 to 6 The controllable release balloon catheter shown in the figure comprises a coaxially arranged microcatheter 1 and an outer sleeve 2, and a catheter seat 3; Figure 1 and Figure 2 As shown in , in the embodiment of the present invention, there is a gap between the microcatheter 1 and the outer sleeve 2, so that the outer sleeve 2 can move relative to the microcatheter 1 in the axial direction, that is, the outer sleeve 2 can be axially extended; please continue to refer to Figure 1, in an embodiment of the present invention, the catheter hub 3 is connected to the proximal ends of the microcatheter 1 and the outer catheter 2. The catheter hub 3 includes a liquid filling cavity 31 communicating with the proximal end of the microcatheter 1 and a filling cavity 32. The filling cavity 32 is in communication with the gap between the outer catheter 2 and the microcatheter 1. A filling balloon 21 communicating with this gap is provided at the distal end of the outer catheter 2. When filling liquid is injected into the gap between the outer catheter 2 and the microcatheter 1 through the filling cavity 32, the filling balloon 21 can expand to block the blood flow at the proximal end and prevent the embolizing agent from flowing back. It should be noted here that in the embodiment of the present application, the proximal end refers to the end close to the operator, and the distal end refers to the end far from the operator. During specific operation, generally hold the catheter hub 3 and inject a filling agent into the filling cavity 32 to expand the balloon or inject an embolizing agent into the liquid filling cavity 31 to block the diseased blood vessel. In the embodiment of the present application, the material of the filling balloon 21 is silicone or TPE material, namely thermoplastic elastomer, which has certain elasticity, has a larger volume when filled, and expands in volume; in the embodiment of the present application, through the setting of the filling balloon 21, the filling balloon 21 can be used to block the proximal blood supply artery, which can replace the method of blocking the proximal blood supply artery by the reflux of the embolizing agent in the prior art and improve the safety of the operation.

[0034] Such as Figure 2As shown in the figure, the microcatheter 1 includes a body section 11 and a detachable section 12. The proximal end of the detachable section 12 is detachably connected to the distal end of the body section 11, and the inner cavity of the detachable section 12 communicates with the inner cavity of the body section 11 to form the microcatheter 1. It should be noted that, in some embodiments of the present application, the inner layer of the microcatheter 1 can be made of PTFE material, that is, polytetrafluoroethylene material, the middle layer is a metal reinforcement layer, and the outer layer is a polymer layer. In this embodiment, the body section 11 has a three-layer structure, and the detachable section 12 has a single-layer structure, and the single-layer structure of the detachable section 12 is made of PTFE material. Those skilled in the art can make selections according to needs. In the embodiment of the present application, a detaching structure 4 is formed between the distal end of the outer sheath 2 and the proximal end of the detachable section 12. The detaching structure 4 is configured such that when the outer sheath 2 moves proximally relative to the microcatheter 1 until the detachable section 12 is outside the outer sheath 2, the body section 11 is separated from the detachable section 12. Of course, it should be noted that the detaching structure 4 has various structural forms. For example, the detachable section 12 and the body section 11 are in an abutting manner, and are connected by extrusion, mechanical snap connection or tearable connection by means of the end of the outer sheath 2. When the outer sheath 2 contracts proximally such that the force for the detachable section 12 to break away from the outer sheath 2 disappears and the detachable section 12 is outside the outer sheath 2, or under the further pushing action of the outer sheath 2, the detachable section 12 is separated from the body section 11, and then the detachable section 12 is separated from the balloon catheter as a whole, leaving the detachable section 12 in the diseased blood vessel. In the embodiment of the present invention, the detachable section 12 is made of a single-layer polymer material, which will not cause damage to the blood vessel at the diseased site, thus greatly improving the safety of catheter withdrawal. In an embodiment of the present invention, the outer sheath 2 is disposed on the outer peripheral side of the detaching structure 4 to wrap the detaching structure 4, preventing the reflux of the embolizing agent during the operation from wrapping the detaching structure 4 and causing difficulties in detachment. With such a setting, the outer sheath 2 can isolate the embolizing agent. Even if there is a small amount of adhesion of the embolizing agent on the outer surface of the outer sheath 2, due to the movably arranged outer sheath 2, it can be easily separated under an external force.

[0035] In the above embodiment, through the detaching structure 4 formed by the distal end of the outer sheath 2 and the detachable section 12 of the microcatheter 1, after the microcatheter 1 completes the occlusion of the diseased blood vessel, it remains in the diseased blood vessel by means of the detachment of the detachable section 12, and the detachment is achieved by the relative movement of the outer sheath 2 during detachment. Only the structure of the microcatheter 1 itself is displaced, which does not affect the detachable section 12 retained in the embolizing agent, that is, it does not damage the blood vessel and will not cause the embolizing agent to escape. Compared with the prior art, the detachment timing of the microcatheter 1 is accurately controllable and has high safety.

[0036] On the basis of the above embodiment, please continue to refer to Figure 2, in the embodiment of the present application, the diameter of the release section 12 is smaller than that of the body section 11. In this embodiment, the inner diameter of the release section 12 is smaller than that of the body section 11, and the outer diameter of the release section 12 is smaller than that of the body section 11, and the connection is transitionally connected through a conical surface; in another embodiment of the present invention, the diameter of the release section 12 is smaller than that of the body section 11, and the diameter here refers to the outer diameter, that is, in this embodiment, the inner diameter of the release section 12 is equal to that of the body section 11, and the outer diameter of the release section 12 is smaller than that of the body section 11. The inner diameter of the release section 12 is equal to that of the body section 11, forming a smooth internal delivery channel, and it will not cause the resistance of the embolizing agent to suddenly increase at the connection due to the sudden decrease of the inner diameter, resulting in an increase in the reaction force of the release section 12, which is likely to cause the separation of the contact surface at the connection or cause the release section 12 to generate a micro-displacement, having a negative impact on the operation; please continue to refer to Figure 2 , the proximal end of the release section 12 is flared. By setting the diameter of the release section 12 to be smaller than that of the body section 11, on the one hand, it can improve the accuracy of inserting the distal end of the release section 12 into the diseased blood vessel, and on the other hand, it can reduce the contact area with the outer sheath 2 and thus reduce the friction force, reducing the operation difficulty when the outer sheath 2 moves; in addition, by setting the proximal end of the release section 12 to be flared, that is, a flared structure, on the one hand, it can improve the reliability of docking with the body section 11, and on the other hand, when the outer sheath 2 shrinks towards the proximal end, the body section 11 can apply a more stable thrust to the flared section, thereby improving the relative movement accuracy of the release section 12 and avoiding misalignment between the body section 11 and the release section 12.

[0037] In the embodiment of the present application, an exemplary structure of the release structure 4 is as Figure 2 shown in. The release structure 4 includes an inner boss 41 provided at the distal end of the outer sheath 2 and an outer boss 42 provided at the proximal end of the release section 12. The outer boss 42 is proximal to the inner boss 41 before release, and the inner boss 41 and the outer boss 42 form an interleaved sealing structure in the thickness direction of the tube wall. It should be noted here that in the embodiment of the present application, the inner boss 41 refers to a structure that protrudes from the inner wall of the outer sheath 2 towards the outer wall of the release section 12 and fits, and the outer boss 42 refers to a structure that protrudes from the outer wall of the release section 12 towards the inner wall of the outer sheath 2 and fits with the inner wall of the outer sheath 2; as Figure 2 shown in, in the embodiment of the present application, the outer wall of the outer boss 42 is in close contact with the inner wall of the outer sheath 2 to form a sealing structure to prevent liquid leakage when the filling balloon 21 is filled with liquid. In addition, it should also be noted here that the interleaved sealing means that under the axial blocking and extrusion action of the inner boss 41, the outer boss 42 can maintain close contact with the inner wall of the outer sheath 2 before release to improve the sealing performance.

[0038] Optionally, in the embodiments of the present application, the staggered arrangement of the inner boss 41 and the outer boss 42 is achieved by deforming the distal end of the outer sheath 2. In the embodiments of the present application, the distal end of the outer sheath 2 is made of a deformable polymer material, and the outer boss 42 is a ring structure, and the inner boss 41 is discontinuously arranged in the circumferential direction. In this way, when the distal end of the outer sheath 2 expands and deforms, it is more conducive to the expansion of the distal end of the outer sheath 2. If the inner boss 41 is continuously arranged, that is, it is arranged around the inner wall of the distal end of the outer sheath 2, when the inner boss 41 crosses the outer boss 42, the thickness of the inner boss 41 is greater than the thickness of the outer sheath 2. To ensure the engagement strength, the inner boss 41 itself is difficult to deform, and the outer sheath 2 is relatively easy to deform relative to the inner boss 41. Therefore, the inner boss 41 is discontinuously arranged, which can not only ensure the engagement with the outer boss 42, but also ensure that the outer sheath 2 deforms at the gap of the inner boss 41. In the embodiments of the present application, the outer boss 42 is a continuous ring structure to ensure the sealing performance. And in the embodiments of the present application, the specific disengagement method of the disengagement section 12 is as Figures 3 to 5 shown in, by using a deformable material at the distal end of the outer sheath 2 and discontinuously arranging the inner boss 41 in the circumferential direction, when the outer sheath 2 contracts towards the proximal end, under the extrusion of the outer boss 42, the distal end of the outer sheath 2 and the inner boss 41 expand and deform together, so that during the continuous movement of the outer sheath 2 towards the proximal end, the outer boss 42 on the disengagement section 12 moves towards the distal end relative to the inner boss 41 on the outer sheath 2 as Figure 5 shown in. When the disengagement section 12 moves to the outside of the outer sheath 2, at this time, the distal end of the outer sheath 2 returns to its original shape from the expanded shape. Due to the loss of the acting force of the outer sheath 2 and the inner boss 41, the disengagement section 12 is separated from the body section 11. Of course, it should be noted here that at the butt joint end face of the disengagement section 12 and the body section 11, it can also be set in a glued or tearable connection manner. After the outer sheath 2 contracts until the disengagement section 12 moves relative to the distal end of the outer sheath 2, the distal end of the outer sheath 2 can push the disengagement section 12 again after contraction to ensure the separation between the disengagement section 12 and the body section 11.

[0039] Please continue to refer to Figure 2 , in the embodiments of the present invention, in order to facilitate the expansion of the inner boss 41, the surfaces of the inner boss 41 and the outer boss 42 facing each other are parallel inclined surfaces, and the outer ends of the inclined surfaces are close to the catheter seat 3. It should be noted that the surfaces facing each other refer to the surfaces of the inner boss 41 and the outer boss 42 that are close to and in contact with each other. The inclination is relative to the planes of the inner boss 41 and the outer boss 42, and the inclination angle is 25° to 75°. As a preferred solution, the inclination angle of the inclined surface is 45°. That is, as Figure 2As shown in the figure, the abutting surface between the outer boss 42 and the inner boss 41 is inclined, so that the end surface of the outer boss 42 facing the inner boss 41 is in a conical structure. Through this form of setting, when the outer sleeve 2 moves towards the proximal end, the end surface of the outer boss 42 on the release section 12 will apply a radially outward expanding force to the inner boss 41, thereby making it easier for the distal end of the outer sleeve 2 and the inner boss 41 to deform, thus reducing the operation difficulty.

[0040] In addition, in the embodiment of the present application, in order to prevent liquid from entering the inside of the microcatheter 1 from the docking part of the release section 12 and the body section 11 when filling the inflation balloon 21 with liquid, as Figure 2 shown in the figure, the proximal end of the release section 12 is closely docked with the distal end of the body section 11 before release, and a first sealing layer 43 is coated on the outside of the docking part. It should be noted here that the sealing layer at this place maintains the sealed connection between the body section 11 and the release section 12 by the acting force between the inner boss 41 and the outer boss 42. After the first sealing layer 43 is released from the restraint of external force, it is very easy to fall off and will not affect the release of the release section 12.

[0041] In addition, please continue to refer to Figure 2 , since the inner boss 41 is intermittently arranged, in order to further prevent leakage when filling the inflation balloon 21 with liquid, the distal end of the outer sleeve 2 is in a necked shape, and a second sealing layer 44 is coated on the outer area where the distal end of the outer sleeve 2 contacts the release section 12. It should also be noted here that the sealing strength of the second sealing layer 44 can ensure the filling pressure and at the same time can meet the requirement of losing the seal when moving the outer sleeve 2 and can move relatively; in the embodiment of the present application, since the tube is withdrawn after the embolizing agent is filled, the movement of the outer sleeve 2 will not cause the filling liquid to enter the diseased blood vessel. On the one hand, the embolizing agent has formed a cast gel mass in the diseased blood vessel, and on the other hand, the inflation balloon 21 has also been pumped and contracted before withdrawing the tube. Therefore, when pulling the outer sleeve 2 to break the second sealing layer 44, the situation that the filling liquid enters the diseased blood vessel will not occur, and the safety of the operation can be ensured.

[0042] Please continue to refer to Figure 6, in the embodiments of the present application, in order to facilitate the shrinking operation of the outer sleeve 2, the proximal end of the outer sleeve 2 has a telescopic section 22, and the telescopic section 22 is made of a flexible polymer material such as polyethylene, polypropylene, polyvinyl chloride, polycarbonate, and polylactic acid. In one embodiment, the telescopic section 22 is made of PTFE material. The telescopic section 22 here can be set to a structure similar to a corrugated pipe, which is easy to shrink in the axial direction of the microcatheter 1. There are also various flexible polymer materials, for example, it can be thermoplastic polyurethane elastomer, or polysiloxane, polycaprolactone, etc. The remaining part of the body section 11 of the microcatheter 1 can be set to a straight tube structure. In this way, only by pulling or pushing the telescopic section 22 can the outer sleeve 2 be conveniently shrunk; in addition, in order to operate the telescopic section 22 more conveniently, please continue to refer to Figure 6 , the distal end of the telescopic section 22 also has a pull ring 23 for controlling the movement of the outer sleeve 2. It should be noted here that the pull ring 23 can be made of a hard material such as hard plastic or metal. When specifically operating, only by holding the pull ring 23 and pulling or pushing can the telescopic section 22 be telescoped, and under the pulling or pushing action of the pull ring 23, the outer sleeve 2 can be conveniently moved.

[0043] In the embodiments of the present application, in order to facilitate the observation of the surgical situation during the operation, a radiopaque ring 5 is provided at the distal end of the release section 12 and inside the inner boss 41 and the outer boss 42. It should be noted here that the radiopaque ring 5 is usually made of a material with high density and good X-ray blocking performance, which can be clearly shown under X-rays to help the surgeon accurately determine the position under the guidance of the imaging device, thereby better improving the safety of the operation. By providing the radiopaque ring 5 at the distal end of the release section 12, it can be clearly known whether the release section 12 has entered the diseased blood vessel. By providing the radiopaque ring 5 on the inner boss 41 and the outer boss 42, since the inner boss 41 is intermittently provided and the radiopaque ring 5 therein is also intermittently provided, it can be accurately judged whether the release section 12 is released.

[0044] Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A controllable detachable balloon catheter, characterized in that, Comprising: A microcatheter and an outer sheath arranged coaxially, wherein the outer sheath is movably arranged axially relative to the microcatheter; A catheter hub connected to the proximal ends of the microcatheter and the outer sheath. The catheter hub includes a liquid filling cavity communicating with the proximal end of the microcatheter and a filling cavity. The filling cavity communicates with the gap between the outer sheath and the microcatheter. A filling balloon communicating with this gap is provided at the distal end of the outer sheath; The microcatheter includes a body section and a detachable section. The proximal end of the detachable section is detachably connected to the distal end of the body section, and the inner cavity of the detachable section communicates with the inner cavity of the body section to form the microcatheter; Wherein, a detaching structure is formed between the distal end of the outer sheath and the proximal end of the detachable section. The detaching structure is configured such that when the outer sheath moves proximally relative to the microcatheter until the detachable section is outside the outer sheath, the body section is separated from the detachable section; The detaching structure includes an inner boss provided at the distal end of the outer sheath and an outer boss provided at the proximal end of the detachable section. The outer boss is proximal to the inner boss before detachment, and an interleaved sealing structure is formed between the inner boss and the outer boss in the wall thickness direction; The distal end of the outer sheath is made of a deformable material. When the outer sheath contracts proximally, the distal end of the outer sheath and the inner boss expand and deform together. When the detachable section moves outside the outer sheath, the distal end of the outer sheath returns to its original shape from the expanded shape; The outer boss is in a ring structure, and the inner boss is intermittently arranged in the circumferential direction.

2. The controllable release balloon catheter according to claim 1, wherein The diameter of the detachable section is smaller than that of the body section, and the proximal end of the detachable section is flared.

3. The controllable release balloon catheter according to claim 1, characterized in that, The surfaces of the inner boss and the outer boss facing each other are parallel inclined surfaces, and the outer ends of the inclined surfaces are close to the catheter hub.

4. The controllable detachable balloon catheter according to claim 2, wherein The proximal end of the detachable section is in close butt joint with the distal end of the body section before detachment, and a first sealing layer is coated on the outside of the butt joint.

5. The controllable detachable balloon catheter according to claim 4, wherein The distal end of the outer sheath is in a necked shape, and a second sealing layer is coated on the outer region where the distal end of the outer sheath contacts the detachable section.

6. The controllable detachable balloon catheter according to claim 1, wherein, The proximal end of the outer sheath has a telescopic section made of a flexible polymer material.

7. The controllable detachable balloon catheter according to claim 6, characterized in that, A pull ring is further provided at the distal end of the telescopic section for controlling the movement of the outer sheath.

8. The controllable release balloon catheter according to claim 1, characterized in that, A radiopaque ring is provided in the distal end of the detachable section and inside the inner boss and the outer boss.

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