Vascular intervention catheter, intravascular cooling system and cooling method for brain protection

Abstract

The application provides a vascular intervention catheter, an intravascular cooling system and a cooling method for brain protection, comprising a catheter seat, a tube body, an injection extension tube and a vacuum extension tube; one end of the tube body is connected with one end of the catheter seat, and the injection extension tube and the vacuum extension tube are arranged on the catheter seat; a main intervention tube, a cooling medium injection tube and a vacuum cavity are arranged in the tube body; the main intervention tube extends along the axial direction of the tube body, and the vacuum cavity is formed between the outer side wall of the main intervention tube and the inner side wall of the tube body; the vacuum cavity is connected with the vacuum extension tube in communication, and the injection extension tube is connected with the vacuum cavity in communication through the cooling medium injection tube. The application can be used for protecting the brain nerves of a stroke patient, and has the advantages of high cooling efficiency, simple operation, safety and reliability and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular, to a blood vessel intervention catheter for brain protection, an intravascular cooling system and a cooling method, especially an intravascular catheter for hypothermic brain protection, a selective intravascular cooling system and a method for selective brain cooling. BACKGROUND

[0002] Hypothermia therapy is an effective neuroprotective measure, which can be used for the treatment of various nervous system diseases such as stroke and craniocerebral injury. It has been proved in animal experiments and clinical trials that it has a protective effect on ischemic brain injury. Existing hypothermia therapy methods mainly include systemic cooling and selective brain cooling. Systemic cooling is achieved by surface cooling, body cavity cooling and blood cooling. There are problems of slow cooling speed and easy to cause adverse reactions such as shivering. In order to avoid the adverse reactions of systemic cooling, researchers have developed various selective cooling catheters.

[0003] Cooling blood perfusion catheters such as TwinFlo catheter adopt a double-lumen design, which extracts blood from the aorta, cools it outside the body, and then perfuses the cooled blood into the carotid artery to achieve selective brain cooling. This method can quickly achieve deep brain cooling, but it needs to establish an extracorporeal circulation system, which is complex to operate, and in the process of cooling autologous blood in extracorporeal circulation, blood cells are prone to lysis due to temperature mutation and mechanical pump interference, and cooled blood is prone to be heated by the surrounding environment during input into the blood vessel. Patent document US8109897 discloses a selective cooling catheter, which is a double-lumen catheter and is provided with a blood flow blocking device at the distal end. After blocking the blood flow, the body temperature blood enters from the distal end of the first lumen and is cooled in the cooling device at the proximal end of the catheter, and then enters from the proximal end of the second lumen and is injected into the blood vessel from the distal end of the second lumen. Patent document US8353942 discloses a selective cooling catheter comprising three lumens, wherein the main lumen is used to inject cooled blood into the blood vessel, and the two side lumens are used to circulate cooling liquid, so that the cooled blood maintains low temperature during input.

[0004] Cooling saline perfusion catheters achieve local cooling by perfusing cold physiological saline. For example, the Khione catheter wall is made of thermal insulation material to reduce the degree of heating of physiological saline from the proximal end to the distal end of the catheter during input. This method is relatively simple to operate, but direct injection of cold saline into the blood vessel may exacerbate brain edema, and the saline is prone to be heated by the surrounding environment during transportation.

[0005] Closed heat exchange catheter achieves cooling by delivering coolant through a closed circulation system. Patent document CN220193319 discloses a hypothermia central venous balloon catheter, which is provided with a main cavity and two side cavities. Coolant enters the balloon at the distal end of the catheter through one of the side cavities and returns to the proximal end of the catheter through the other side cavity. Based on a similar cooling principle, patent document CN115212027 discloses a low-temperature brain protection catheter comprising multiple internal heat exchange balloons. The catheter structure is complex, and the balloons may affect blood flow. Patent document US20220226150 discloses a cooling catheter provided with a lumen along the catheter for circulating cooling medium. The cooling medium comprises a liquid and a solid with a melting point lower than 37℃ mixed in the liquid. The heat of the blood flow around the catheter is taken away by the melting of the solid.

[0006] Therefore, there is an urgent need to develop a high-efficiency, simple and safe selective brain cooling device. An ideal cooling catheter should have the following characteristics: 1) can quickly and effectively achieve local cooling; 2) avoid injecting additional liquid into the blood vessel; 3) simple and reliable structure; 4) little effect on blood flow. The present application provides a new intravascular cooling catheter based on the principle of phase change cooling, which can overcome the shortcomings of the prior art. SUMMARY

[0007] In view of the defects in the prior art, the purpose of the present application is to provide a vascular interventional catheter for brain protection, an intravascular cooling system and a cooling method.

[0008] According to the present application, a vascular interventional catheter for brain protection is provided, comprising: a catheter seat, a catheter body, an injection extension tube and a vacuum extension tube.

[0009] One end of the catheter body is connected to one end of the catheter seat, and the injection extension tube and the vacuum extension tube are arranged on the catheter seat.

[0010] A main interventional tube, a cooling medium injection tube and a vacuum cavity are arranged in the catheter body. The main interventional tube extends along the axial direction of the catheter body, and the vacuum cavity is formed between the outer side wall of the main interventional tube and the inner side wall of the catheter body.

[0011] The vacuum cavity is in communication with the vacuum extension tube, and the injection extension tube is in communication with the vacuum cavity through the cooling medium injection tube.

[0012] Cooling medium is injected from the outside of the body through the injection extension tube, delivered to the vacuum cavity through the cooling medium injection tube, spontaneously phase changes in the vacuum cavity, and utilizes phase change to take away the heat of the blood flow around the catheter.

[0013] Preferably, the two ends of the catheter body are proximal end and distal end, respectively.

[0014] The proximal end is connected to the catheter hub; one end of the cooling medium injection tube is in communication with the injection extension tube, and the other end of the cooling medium injection tube is located in the vacuum cavity at the distal end position;

[0015] The cooling medium is injected from outside the body through the injection extension tube and is transported to the vacuum cavity at the distal end position through the cooling medium injection tube.

[0016] Preferably, the main intervention tube extends into the catheter hub;

[0017] An injection buffer cavity is provided in the catheter hub, which is formed between the outer wall of the main intervention tube and the inner wall of the catheter hub;

[0018] The injection extension tube is in communication with the injection buffer cavity, and the injection buffer cavity is in communication with the vacuum cavity through the cooling medium injection tube.

[0019] Preferably, the distal end is provided with a distal end sealing ring, which is located between the outer wall of the main intervention tube and the inner wall of the tube body;

[0020] A vacuum sealing ring is provided in the catheter hub adjacent to the position of the vacuum extension tube, which is located between the outer wall of the main intervention tube and the inner wall of the catheter hub;

[0021] An injection sealing ring is provided in the catheter hub adjacent to the position of the injection extension tube, which is located between the outer wall of the main intervention tube and the inner wall of the catheter hub;

[0022] The cavity space between the distal end sealing ring and the vacuum sealing ring is the vacuum cavity, and the cavity space between the vacuum sealing ring and the injection sealing ring is the injection buffer cavity.

[0023] Preferably, the vascular intervention catheter further comprises: a main cavity extension tube;

[0024] The main cavity extension tube is connected to the other end of the catheter hub.

[0025] Preferably, the size of the main intervention cavity is suitable for accommodating a guide wire, a microcatheter and an intermediate catheter;

[0026] And / or, the material of the distal end sealing ring, the vacuum sealing ring and the injection sealing ring is one or more of silicone, polyurethane, polytetrafluoroethylene and adhesive;

[0027] And / or, the cooling medium injection tube is provided with one or more injection holes on the tube body at the distal end position; the distal end is provided with a developing ring, which is arranged in the axial position of the injection hole;

[0028] And / or, the outer surface of the tube body at the distal end is provided with a hydrophilic coating; the hydrophilic coating is one or more of polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, polyethylene imine, polyacrylamide, polyacrylic acid or polysaccharide material.

[0029] Preferably, the cooling medium comprises physiological saline; the pressure maintained in the vacuum cavity is able to reduce the boiling point of the cooling medium to below physiological temperature;

[0030] And / or, the material of the cooling medium injection tube is PEEK;

[0031] And / or, the tube body is provided with a temperature sensor at the distal end, which is used to monitor the local temperature;

[0032] And / or, the outer surface of the tube body is provided with an anticoagulant layer; the anticoagulant layer is one of heparin, citrate and hydrogel;

[0033] And / or, the inner and outer surfaces of the distal end are provided with a textured structure for increasing the surface area to improve heat transfer efficiency.

[0034] Preferably, the catheter seat is provided with a first outer threaded luer connector and a first inner threaded luer connector;

[0035] The injection extension tube and the vacuum extension tube are provided with a second inner threaded luer connector for connecting the first outer threaded luer connector;

[0036] The main cavity extension tube is provided with a second outer threaded luer connector for connecting the first inner threaded luer connector.

[0037] The present application also provides an intravascular cooling system for brain protection, comprising the above-mentioned intravascular intervention catheter for brain protection;

[0038] Further comprising: a cooling medium delivery device and a negative pressure device;

[0039] The cooling medium delivery device is in communication with the cooling medium injection tube through the injection extension tube;

[0040] The negative pressure device is in communication with the vacuum cavity through the vacuum extension tube;

[0041] The cooling medium injection tube and the vacuum cavity are fluidly connected at the distal end of the tube body;

[0042] The main intervention tube is fluidly isolated from the cooling medium injection tube and the vacuum cavity;

[0043] The cooling medium injection tube and the vacuum cavity are fluidly isolated from the blood outside the catheter.

[0044] The application also provides a cooling method for brain protection, using the above-mentioned intravascular cooling system for brain protection, specifically comprising the following steps:

[0045] Step S1: advancing a vascular interventional catheter to a designated cerebral artery;

[0046] Step S2: connecting the vacuum extension tube on the catheter seat to the negative pressure device, so that the vacuum cavity in the catheter is in communication with the negative pressure device, and a low-pressure space is formed at the distal end of the catheter;

[0047] Step S3: connecting the injection extension tube on the catheter seat to the cooling medium conveying device, so that the cooling medium injection tube is in communication with the cooling medium conveying device;

[0048] Step S4: injecting cooling medium into the vacuum cavity through the cooling medium injection tube, inducing cooling medium vaporization under low-pressure conditions, and generating local cooling.

[0049] Compared with the prior art, the application has the following beneficial effects:

[0050] 1. The application adopts the design of a vacuum cavity structure cooperating with a cooling medium injection tube, uses a low-pressure environment to make the cooling medium spontaneously vaporize at the distal end of the catheter and absorb heat from the blood flow around the catheter, and avoids the risk of aggravating brain edema caused by directly injecting cooling saline into the blood vessel in the traditional cooling catheter or the risk of blood cell lysis caused by injecting cooling blood.

[0051] 2. The cooling medium of the application is transported through the cooling intervention tube and only enters the vacuum cavity at the distal end of the catheter, so that the phase change cooling of the catheter of the application only occurs at the distal end of the catheter, avoiding the problem that the cooling saline or blood in the traditional cooling catheter is heated by the surrounding environment during the transportation from the proximal end to the distal end of the catheter, and having higher cooling efficiency, while also reducing the influence on other tissues to achieve precise local hypothermia.

[0052] 3. The main intervention tube, vacuum cavity and cooling medium injection tube in the catheter of the application are isolated by a sealing ring, avoiding the leakage of the cooling medium into the blood vessel and the connection of the blood vessel with the vacuum environment, and at the same time, the main intervention tube can be used for the transportation of a guide wire and a catheter, without affecting the performance of the existing vascular interventional surgery, and is expected to be able to deliver the catheter of the application to the distal cerebral blood vessel to achieve more local selective hypothermic brain protection. BRIEF DESCRIPTION OF DRAWINGS

[0053] Other features, objects and advantages of the application will become more apparent through reading the following detailed description of non-limiting embodiments, made with reference to the following drawings:

[0054] Figure 1Structure diagram of the vascular interventional catheter of the present application;

[0055] Figure 2 Radial section view of the distal end of the vascular interventional catheter of the present application;

[0056] Figure 3 Axial section of the vascular interventional catheter of the present application Figure 1 ;

[0057] Figure 4 Axial section of the vascular interventional catheter of the present application Figure 2 ;

[0058] Figure 5 Axial section of the vascular interventional catheter of the present application Figure 4 ;

[0059] Figure 6 Axial section of the vascular interventional catheter of the present application Figure 4 ;

[0060] Figure 7 Axial section of the vascular interventional catheter of the present application Figure 4 ;

[0061] Figure 8 Axial section of the vascular interventional catheter of the present application Figure 4 ;

[0062] Figure 9 Axial section of the vascular interventional catheter of the present application Figure 4 ;

[0063] Figure 10 Cooling working principle diagram of the vascular interventional catheter of the present application;

[0064] Figure 11 Cooling calculation result diagram of the vascular interventional catheter of the present application.

[0065] The diagram shows:

[0066] 1, catheter seat; 2, tube body; 3, injection extension tube; 4, vacuum extension tube; 5, main cavity extension tube; 21, main interventional tube; 22, cooling medium injection tube; 23, distal end sealing ring; 24, vacuum sealing ring; 25, injection sealing ring; 31, injection buffer cavity; 41, vacuum cavity; 201, proximal end of tube body; 202, distal end of tube body; 211, main interventional cavity; 221, injection hole. DETAILED DESCRIPTION

[0067] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0068] Example 1

[0069] like Figures 1-11 As shown, this embodiment provides a vascular interventional catheter for brain protection, including: a catheter seat 1, a tube body 2, an injection extension tube 3, and a vacuum extension tube 4; one end of the tube body 2 is connected to one end of the catheter seat 1, and the injection extension tube 3 and the vacuum extension tube 4 are disposed on the catheter seat 1; the tube body 2 is provided with a main interventional tube 21, a cooling medium injection tube 22, and a vacuum chamber 41; the main interventional tube 21 extends axially along the tube body 2, and the vacuum chamber 41 is formed between the outer wall of the main interventional tube 21 and the inner wall of the tube body 2; the vacuum chamber 41 is connected to the vacuum extension tube 4, and the injection extension tube 3 is connected to the vacuum chamber 41 through the cooling medium injection tube 22; the cooling medium is injected externally through the injection extension tube 3, and transported to the vacuum chamber 41 through the cooling medium injection tube 22, where it undergoes a spontaneous phase change, using the phase change to remove heat from the blood flow around the catheter. The vascular interventional catheter also includes: a main lumen extension tube 5; the main lumen extension tube 5 is connected to the other end of the catheter seat 1.

[0070] The catheter seat 1 is provided with a first external thread Luer connector and a first internal thread Luer connector; the injection extension tube 3 and the vacuum extension tube 4 are provided with a second internal thread Luer connector for connecting the first external thread Luer connector; the main cavity extension tube 5 is provided with a second external thread Luer connector for connecting the first internal thread Luer connector.

[0071] The main interventional cavity 211 is sized to accommodate the guidewire, microcatheter, and intermediate catheter. The cooling medium injection tube 22, located at its distal end 202, has one or more injection holes 221 on its body; a contrast ring is provided at the distal end 202, positioned axially along the injection hole 221. The cooling medium includes physiological saline; the pressure maintained within the vacuum chamber 41 lowers the boiling point of the cooling medium below physiological temperature. The cooling medium injection tube 22 is made of PEEK.

[0072] The two ends of the tube body 2 are a proximal end 201 and a distal end 202, respectively; the proximal end 201 is connected with the catheter seat 1; one end of the cooling medium injection tube 22 is communicated with the injection extension tube 3, and the other end of the cooling medium injection tube 22 is located in the vacuum cavity 41 at the position of the distal end 202; the cooling medium is injected from the outside of the body through the injection extension tube 3 and is delivered to the vacuum cavity 41 at the position of the distal end 202 through the cooling medium injection tube 22. The main intervention tube 21 extends into the catheter seat 1; the injection buffer cavity 31 is arranged in the catheter seat 1 and is formed between the outer side wall of the main intervention tube 21 and the inner side wall of the catheter seat 1; the injection extension tube 3 is communicated with the injection buffer cavity 31, and the injection buffer cavity 31 is communicated with the vacuum cavity 41 through the cooling medium injection tube 22. The outer surface of the tube body at the position of the distal end 202 is provided with a hydrophilic coating; the hydrophilic coating is one or more of polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, polyethylene imine, polyacrylamide, polyacrylic acid or polysaccharide material.

[0073] The distal end 202 is provided with a distal end sealing ring 23 located between the outer side wall of the main intervention tube 21 and the inner side wall of the tube body 2; the catheter seat 1 is provided with a vacuum sealing ring 24 adjacent to the position of the vacuum extension tube 4, and the vacuum sealing ring 24 is located between the outer side wall of the main intervention tube 21 and the inner side wall of the catheter seat 1; the catheter seat 1 is provided with an injection sealing ring 25 adjacent to the position of the injection extension tube 3, and the sealing ring 25 is located between the outer side wall of the main intervention tube 21 and the inner side wall of the catheter seat 1; the cavity space between the distal end sealing ring 23 and the vacuum sealing ring 24 is the vacuum cavity 41, and the cavity space between the vacuum sealing ring 24 and the injection sealing ring 25 is the injection buffer cavity 31. The materials of the distal end sealing ring 23, the vacuum sealing ring 24 and the injection sealing ring 25 are one or more of silicone, polyurethane, polytetrafluoroethylene and adhesive;

[0074] The tube body 2 is provided with a temperature sensor at the position of the distal end 202, and the temperature sensor is used for monitoring the local temperature. The outer surface of the tube body 2 is provided with an anticoagulant layer; the anticoagulant layer is one of heparin, citrate and hydrogel. The inner and outer surfaces of the distal end 202 are provided with a textured structure for increasing the surface area to improve the heat transfer efficiency.

[0075] The embodiment also provides an intravascular cooling system for brain protection, which comprises the intravascular intervention catheter for brain protection described above and further comprises a cooling medium delivery device and a negative pressure device; the cooling medium delivery device is communicated with the cooling medium injection tube 22 through the injection extension tube 3; the negative pressure device is communicated with the vacuum cavity 41 through the vacuum extension tube 4; the cooling medium injection tube 22 and the vacuum cavity 41 are fluidly connected at the distal end 202 of the tube body 2; the main intervention tube 21 is fluidly isolated from the cooling medium injection tube 22 and the vacuum cavity 41; the cooling medium injection tube 22 and the vacuum cavity 41 are fluidly isolated from the blood outside the catheter.

[0076] The embodiment also provides a cooling method for brain protection, using the above-mentioned intravascular cooling system for brain protection, and specifically comprising the following steps:

[0077] Step S1: advancing the vascular intervention catheter to the designated cerebral artery;

[0078] Step S2: connecting the vacuum extension tube 4 on the catheter seat 1 to the negative pressure device, so that the vacuum cavity 41 in the catheter 2 is in communication with the negative pressure device, and a low-pressure space is formed at the distal end 202 of the catheter 2;

[0079] Step S3: connecting the injection extension tube 3 on the catheter seat 1 to the cooling medium delivery device, so that the cooling medium injection tube 22 is in communication with the cooling medium delivery device;

[0080] Step S4: injecting the cooling medium into the vacuum cavity 41 through the cooling medium injection tube 22, and inducing the cooling medium to vaporize under the low-pressure condition to generate local cooling.

[0081] The embodiment provides an intravascular hypothermia brain protection catheter using phase change cooling, comprising a catheter seat, a tube body installed on the catheter seat, an injection extension tube, a vacuum extension tube, a main cavity extension tube, a sealing ring distributed along the tube body in the axial direction, and a vacuum cavity and an injection buffer cavity formed by the sealing ring. The tube body is internally provided with an axially extending main intervention tube and one or more injection tubes. The main cavity extension tube is used to deliver a guide wire, a microcatheter or other intervention instruments.

[0082] When hypothermia brain protection is performed, an extracorporeal vacuum source is connected to the catheter through the vacuum extension tube to create a vacuum cavity in the catheter, and the cooling medium is injected from the outside of the body through the injection extension tube and delivered to the distal end of the catheter through the injection tube, and spontaneously phase changes in the vacuum cavity. The phase change is used to take away the heat of the blood flow around the catheter, reduce the temperature of the blood flow around the catheter, and thus achieve the purpose of selective brain cooling. The catheter can avoid direct injection of cooling liquid into the blood, and reduce the risk of brain edema. The embodiment can be used to protect the brain nerves of stroke patients, and has the advantages of high cooling efficiency, simple operation, safety and reliability, etc.

[0083] Example 2

[0084] Those skilled in the art can understand the embodiment as a more specific description of Embodiment 1.

[0085] The embodiment provides an intravascular intervention catheter for hypothermia brain protection, comprising a catheter seat 1, a tube body 2 with a proximal end and a distal end installed on the catheter seat 1, an injection extension tube 3, a vacuum extension tube 4, and a main cavity extension tube 5. The injection extension tube 3, the vacuum extension tube 4, and the main cavity extension tube 5 are all arranged on one side of the catheter seat 1, and the proximal end 201 of the tube body 2 is connected to the other side of the catheter seat 1. The temperature range of hypothermia is 28-35℃.

[0086] The tube body 2 is internally provided with an axially extending main intervention tube 21; a vacuum cavity 41 fluidically connected to the vacuum extension tube 4 and isolated from the main intervention tube 21 and the blood fluid outside the catheter; one or more cooling medium injection tubes 22 fluidically connected to the vacuum cavity 41, isolated from the main intervention tube 21 and the blood fluid outside the catheter, and fluidically connected to the injection extension tube 3.

[0087] The vascular intervention catheter further comprises a distal sealing ring 23 located at the distal end 202 of the tube body, a vacuum sealing ring 24 located inside the catheter hub 1 at the proximal end of the vacuum extension tube 4, and an injection sealing ring 25 located inside the catheter hub 1 at the proximal end of the injection extension tube 3. The distal sealing ring 23 and the vacuum sealing ring 24 form a vacuum cavity 41 inside the catheter lumen, fluidically connected to the vacuum extension tube 4 at the distal end 202 of the tube body and isolated from the main intervention lumen 211 inside the main intervention tube 21. The vacuum sealing ring 24 and the injection sealing ring 25 form an injection buffer cavity 31 inside the catheter hub 1, fluidically connected to the injection extension tube 3 and isolated from the main intervention lumen 21.

[0088] The main intervention lumen 211 is sized to accommodate a guidewire, a microcatheter, and an intermediate catheter.

[0089] The distal sealing ring 23, the vacuum sealing ring 24, and the injection sealing ring 25 are made of one or more of silicone, polyurethane, polytetrafluoroethylene, and adhesive.

[0090] The distal end of the cooling medium injection tube 22 comprises one or more injection holes 221.

[0091] The distal end of the cooling medium injection tube 22 is externally provided with a hydrophilic coating. The hydrophilic coating is one or more of polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, polyethylene imine, polyacrylamide, polyacrylic acid, or polysaccharide.

[0092] The cooling medium comprises normal saline. The vacuum cavity 41 maintains sufficient pressure to reduce the boiling point of the cooling medium to below physiological temperature.

[0093] The cooling medium injection tube 22 is made of PEEK.

[0094] The tube body 2 further comprises a temperature sensor located at the distal end 202 of the tube body for monitoring local temperature.

[0095] The tube body 2 is externally provided with an anticoagulant layer. The anticoagulant layer is one of heparin, citrate, and hydrogel.

[0096] The distal end 202 of the tube body is provided with a radiopaque ring. The tube body 2 is provided with a radiopaque ring at the axial position of the injection hole 221.

[0097] The inner and outer surfaces of the distal end 202 of the tube body comprise textures and structures that increase the surface area to enhance heat transfer efficiency.

[0098] The catheter hub 1 further comprises an outer threaded luer and an inner threaded luer, the injection overgrowth tube 3, the vacuum overgrowth tube 4, the main lumen overgrowth tube 5 are respectively provided with the outer threaded luer and the inner threaded luer.

[0099] The embodiment also provides a selective intravascular cooling system, comprising:

[0100] A multi-lumen catheter with a main intervention tube 21, a cooling medium injection tube 22 and a vacuum lumen 41;

[0101] A cooling medium delivery device connected to the cooling medium injection tube 22;

[0102] A vacuum source connected to the vacuum lumen 41;

[0103] The cooling medium injection tube 22 and the vacuum lumen 41 are fluidly connected at the distal end 202 of the tube body;

[0104] The main intervention tube 21 is fluidly isolated from the cooling medium injection tube 22 and the vacuum lumen 41.

[0105] The cooling medium injection tube 22 and the vacuum lumen 41 are fluidly isolated from the blood outside the catheter.

[0106] The intravascular cooling system further comprises a pressure sensor for monitoring the vacuum level.

[0107] The intravascular cooling system further comprises a control mechanism for adjusting the vacuum pressure and the cooling medium flow.

[0108] The intravascular cooling system further comprises a temperature feedback control system.

[0109] The embodiment also provides a method for selective brain cooling, comprising:

[0110] Advancing an intravascular catheter to a designated cerebral artery;

[0111] Connecting a negative pressure device through the vacuum lumen 41 in the catheter to form a low pressure space at the distal end of the catheter;

[0112] Injecting a cooling medium into the vacuum lumen 41 through the cooling medium injection tube 22;

[0113] Inducing the cooling medium to vaporize under low pressure to produce local cooling;

[0114] Maintaining fluid isolation between the main intervention tube 21 and the vacuum lumen 41 and the cooling medium injection tube 22.

[0115] The method of brain cooling further comprises monitoring the local temperature.

[0116] The method of brain cooling further comprises adjusting the vacuum pressure and the cooling medium injection flow rate based on the temperature feedback.

[0117] The method of brain cooling further comprises maintaining the cooling for a predetermined treatment time.

[0118] Example 3

[0119] Those skilled in the art can understand this embodiment as a more specific description of embodiment 1.

[0120] The purpose of this embodiment is to provide an intravascular subcooling brain protection catheter using phase change cooling to solve the problems in the prior art. To achieve this purpose, the technical scheme adopted by this embodiment is as follows:

[0121] The embodiment provides an intravascular subcooling brain protection catheter using phase change cooling, which comprises a catheter seat and a tube body, an injection extension tube, a vacuum extension tube, and a main cavity extension tube installed on the catheter seat. The tube body is internally provided with an axially extending main intervention tube. The vacuum cavity is in fluid isolation with the main intervention tube and in fluid connection with the vacuum extension tube. The one or more cooling medium injection tubes are in fluid isolation with the main intervention tube and in fluid connection with the injection extension tube. The cooling medium injection tube is in fluid isolation with the vacuum cavity at the proximal end of the catheter to avoid the cooling medium being sucked into the vacuum extension tube at the proximal end of the catheter. The cooling medium is injected into the vacuum cavity at the distal end of the catheter through the cooling medium injection tube. The boiling point of the cooling medium is lowered by using vacuum, so that the cooling medium undergoes phase change and takes away heat from the surrounding environment, thereby realizing local cooling.

[0122] Further, the fluid isolation of the main intervention tube, the vacuum cavity, and the cooling medium injection tube is realized by three sealing rings distributed axially along the tube body: a distal end sealing ring located at the distal end of the tube body, a vacuum sealing ring located in the interior of the catheter seat and at the proximal end of the vacuum extension tube, and an injection sealing ring located in the interior of the catheter seat and at the proximal end of the injection extension tube. The distal end sealing ring and the vacuum sealing ring form the vacuum cavity in the tube body, and the vacuum sealing ring and the injection sealing ring form an injection buffer cavity in the catheter seat.

[0123] Further, the outer diameter of the catheter is 0.09 to 0.13 inches, and the inner diameter of the main intervention tube is 0.04 to 0.10 inches, which is suitable for navigation to the internal carotid artery and further, and can be used for delivering a guide wire, a microcatheter, or other interventional instruments.

[0124] Further, the materials of the distal end sealing ring, the vacuum sealing ring, and the injection sealing ring are one or more of silicone, polyurethane, polytetrafluoroethylene, and adhesive, which are used to ensure the fluid isolation of the vacuum cavity and the main intervention tube and the fluid isolation of the cooling medium injection tube and the main intervention tube.

[0125] Further, the distal end of the cooling medium injection tube comprises a plurality of injection holes isolated from each other, for increasing the gasification area of the physiological saline and improving the efficiency of the phase change heat absorption.

[0126] Further, the outer surface of the distal end of the cooling medium injection tube is provided with a hydrophilic coating, for reducing the contact angle of the outer surface of the cooling medium injection tube, increasing the gasification area of the cooling medium and improving the efficiency of the phase change heat absorption. The hydrophilic coating is one of polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, polyethylene imine, polyacrylamide, polyacrylic acid or polysaccharide material.

[0127] Further, the cooling medium is sterile physiological saline.

[0128] Further, the vacuum cavity maintains a pressure low enough to reduce the boiling point of the cooling medium to below physiological temperature. When using physiological saline, the vacuum cavity needs to maintain a pressure less than 6 kPa.

[0129] Further, the manufacturing material of the cooling medium injection tube is PEEK. PEEK has excellent biocompatibility and excellent processing performance, and can be used to manufacture the cooling medium injection tube with an outer diameter less than 0.01 inch and process the extra injection holes on the cooling medium injection tube.

[0130] Further, the distal end of the tube body further comprises a temperature sensor for temperature feedback control, adjusting the vacuum cavity pressure and the cooling medium injection flow according to the current temperature and the preset temperature.

[0131] Further, the outer surface of the tube body is provided with an anticoagulant layer for preventing coagulation caused by the catheter during the process of cooling blood. The anticoagulant layer is one of heparin, citrate and hydrogel.

[0132] Further, the distal end of the tube body is provided with a developing ring for showing the position of the distal end of the catheter during the intervention process.

[0133] Further, the tube body is provided with a developing ring at the proximal end of the injection hole, for showing the cooling area of the catheter during the intervention process.

[0134] Further, the inner and outer surfaces of the distal end of the tube body comprise textures such as waves and array patterns for increasing the surface area, for increasing the heat conduction area with the vacuum cavity and the blood outside the catheter and improving the cooling efficiency.

[0135] Further, the catheter seat further comprises an external threaded luer and an internal threaded luer, and the injection extension tube, the vacuum extension tube and the main cavity extension tube are respectively provided with the external threaded luer and the internal threaded luer, for quick connection with the interfaces of the syringe, the vacuum pump, the physiological saline pump and the hemostatic valve.

[0136] Further, the sub-hypothermic brain protection catheter is connected with a cooling medium reservoir and a vacuum source through a catheter seat to form a selective brain cooling system. A temperature sensor is installed at the distal end of the catheter to detect the temperature of blood around the distal end of the catheter. According to the temperature, the system can adjust the injection flow of the cooling medium reservoir to the catheter and the pressure provided by the vacuum source to control the cooling power and cooling temperature.

[0137] In this embodiment, the vacuum cavity structure is combined with the cooling medium injection tube design. The cooling medium is spontaneously gasified at the distal end of the catheter in a low-pressure environment and absorbs heat from the blood flow around the catheter, avoiding the risk of aggravating brain edema caused by directly injecting cooling saline into the blood vessel in the traditional cooling catheter or the risk of blood cell lysis caused by injecting cooling blood.

[0138] In addition, since the cooling medium is transported through the cooling intervention tube and only enters the vacuum cavity at the distal end of the catheter, the phase change cooling of the catheter of the present application only occurs at the distal end of the catheter, avoiding the problem that the cooling saline or blood in the traditional cooling catheter is heated by the surrounding environment during transportation from the proximal end to the distal end of the catheter, having higher cooling efficiency, while also reducing the impact on other tissues to achieve precise local cooling.

[0139] The main intervention tube, vacuum cavity and cooling medium injection tube in the catheter of this embodiment are isolated by a sealing ring to avoid leakage of the cooling medium into the blood vessel and to avoid connection of the blood vessel with the vacuum environment. At the same time, the main intervention tube can be used for the transportation of guide wires and catheters, without affecting the performance of existing vascular intervention surgery, and is expected to be able to deliver the catheter of the present application to the distal cerebral blood vessels to achieve more local selective hypothermic brain protection.

[0140] Example 4

[0141] Those skilled in the art can understand this embodiment as a more specific description of embodiment 1.

[0142] In this embodiment, "proximal end" and "distal end" refer to the proximal and distal ends relative to the operator. In use, the end close to the doctor or operator is the "proximal end", i.e. the end where the catheter seat is located, and the end away from the doctor or operator is the "distal end", i.e. the end where the cooling medium injection hole is located.

[0143] As Figures 1-11As shown, the multi-lumen interventional catheter of the present embodiment comprises a catheter hub 1, a shaft 2 mounted on one side of the distal end of the catheter hub 1, and an injection extension tube 3, a vacuum extension tube 4 and a main lumen extension tube 5 mounted on one side of the proximal end of the catheter hub 1. The shaft 2 is internally provided with a main interventional tube 21 and one or more cooling medium injection tubes 22 extending axially from the proximal end 201 of the shaft to the distal end 202 of the shaft. The main lumen extension tube 5 and the main interventional tube 21 are fluidly connected for the delivery of guide wires, microcatheters, stents and other interventional devices and the release of contrast agents, embolic agents, cooling agents and other materials.

[0144] The space formed outside the main interventional tube 21 and the cooling medium injection tube 22 in the shaft 2 is a vacuum lumen 41. The vacuum lumen 41 is fluidly connected to the vacuum extension tube 4 to create a low-pressure environment in the vacuum lumen 41 by connecting an external vacuum source. The injection extension tube 3 is fluidly connected to the cooling medium injection tube 22 to deliver cooling medium to the cooling medium injection tube 22 through an external cooling medium delivery device and into the vacuum lumen 41 through the injection hole 221 at the distal end of the cooling medium injection tube 22. Under the low-pressure environment, the boiling point of the cooling medium can be reduced to below the physiological temperature of 37°C, so that the cooling medium spontaneously vaporizes in the vacuum lumen to take away heat from the blood flow around the shaft 2, thereby achieving the purpose of low-temperature brain protection.

[0145] In order to maintain the low-pressure environment in the vacuum lumen 41 and avoid low-pressure leakage into the blood vessel, the shaft 2 is internally provided with a distal end sealing ring 23 at the distal end of the shaft 2 and a vacuum sealing ring 24 at the proximal end of the vacuum extension tube 4, which are distributed axially along the shaft 2.

[0146] In some examples, the catheter further comprises an injection sealing ring 25 at the proximal end of the catheter hub 1. The injection sealing ring 25 and the above-mentioned vacuum sealing ring 24 form an injection buffer lumen 31 in the catheter hub 1 that is fluidly isolated from the above-mentioned vacuum lumen 41. The injection buffer lumen 31 is fluidly connected to the proximal end of the cooling medium injection tube 22. The cooling medium enters the injection buffer lumen 31 through the injection extension tube 3, enters the cooling medium injection tube 22 through the proximal end of the cooling medium injection tube 22, and finally enters the distal end of the vacuum lumen 41 for phase change cooling. Such a design helps the operator to conveniently send the cooling medium into the small cooling medium injection tube 22. In other examples, the injection sealing ring 25 can not be provided, and the cooling medium injection tube 22 can directly extend out of the catheter hub 1 and be fluidly connected to an external cooling medium delivery device.

[0147] In some examples, the outer diameter of the shaft 2 is referred to the long sheath commonly used in current neurointervention, such as Benchmark The outer diameter of the shaft 2 is generally 0.09 to 0.13 inches, and the inner diameter of the main interventional tube is generally greater than 0.04 inches, so as to adapt to the mud eel guide wire and microcatheter commonly used in neurointervention, so as to navigate to the internal carotid artery and further.

[0148] In some embodiments, the distance between the distal end of the cooling medium injection tube 22 and the distal end of the tube body 2 is less than 1 cm, and the distal end of the cooling medium injection tube 22 is provided with a plurality of injection holes 221 arranged in the axial direction, which form a cooling zone with an axial length of about 10 cm at the distal end of the tube body 2. The cooling medium enters the vacuum cavity 41 through the injection holes 221, so that the phase change cooling is concentrated in the cooling zone, preventing large-scale brain cooling. The cooling zone length of 10 cm is approximately equal to the length of the proximal internal carotid artery to the middle cerebral artery, and through this arrangement, selective cooling of one side of the brain and reduction of the impact on the function of the opposite side of the brain can be achieved.

[0149] In some embodiments, the tube body 2 is provided with a visualization ring at the distal end 202 and the position corresponding to the injection hole 221 in the axial direction, which facilitates the operator to identify the position of the catheter tip and the cooling zone during the intervention process.

[0150] In some embodiments, the cooling medium injection tube 22 is made of PEEK. PEEK has excellent biocompatibility and excellent bending resistance and pushability, and can be processed into an ultra-thin-walled catheter through hot extrusion. The cooling medium injection tube 22 with an outer diameter of less than 0.01 inch can be manufactured. In the case of limited outer diameter of the tube body 2, reducing the cooling medium injection tube 22 is beneficial to the main intervention tube 21 having a large enough inner diameter to deliver a guide wire and other instruments. The injection holes 221 provided on the cooling medium injection tube 22 can be obtained by laser processing.

[0151] In some embodiments, the cooling medium can be water, a water-based mixture, or other liquid with a phase change temperature lower than physiological temperature in a low-pressure environment. Further, the cooling medium used must not produce toxic side effects to the human body when accidentally leaked into the blood vessel, such as sterile physiological saline. In the case of using sterile physiological saline, the vacuum source should maintain the absolute pressure in the vacuum cavity 41 to be at least lower than 6 kPa, at which the boiling point of the physiological saline is 37℃, which will spontaneously vaporize in the vacuum cavity 41 and cool the blood by taking away heat from the blood outside the catheter. The cooling power P = ρQL, where ρ is the density, L is the specific latent heat of about 2500 kJ / kg, and Q is the injection flow rate. For all existing cooling saline perfusion catheters, blood cooling is achieved by heat mixing to transfer the internal energy of the blood to the cooling saline, and the cooling power P = ρQΔTCp, where ΔT is the temperature difference between the cooling saline and the blood, and Cp is the specific heat of the saline of about 3.7 kJ / kg oC. Calculation shows that the heat absorbed by 1 mL of physiological saline at room temperature is 18 times that of 1 mL of 0℃ cooling saline injected into the blood. Therefore, the vacuum-induced phase change cooling mechanism used in the present embodiment can avoid direct injection of cooling liquid into the blood vessel, reduce the risk of brain edema, and at the same time achieve the purpose of high-efficiency cooling.

[0152] It is to be noted that the endothermic process mentioned above is only one of the phase change cooling processes. The melting point of the cooling medium from solid to liquid and the sublimation point of the cooling medium from solid to gas can also decrease with the decrease of pressure. For example, water is in solid state at 0℃ and 1 atm. When the pressure is lower than 0.6 kPa, water can sublimate from solid to gas directly and take away a large amount of heat. Therefore, the cooling medium can also be in the form of hydrogel besides liquid.

[0153] In some embodiments, an anti-coagulation layer can be provided on the outer surface of the tube body 2. The anti-coagulation layer can be one or more of heparin, citrate, hydrogel, etc. to prevent the blood in direct contact with the outer surface of the tube body 2 from coagulating when cooled. Figure 5 As shown in FIG. 1, the catheter of the present application injects a cooling medium (e.g. sterile normal saline) into the vacuum cavity 41 of the catheter through the injection tube 22. The cooling medium spontaneously changes phase from solid to liquid or from solid to gas due to the decrease of boiling point at low pressure, and absorbs heat from the blood outside the tube body 2 to achieve the purpose of selective hypothermic brain protection. The heat is transferred from the blood to the outer wall of the catheter by heat convection, and then from the outer wall of the catheter to the inner wall of the catheter by heat conduction. The efficiency of heat transfer is determined by the outer diameter D o , the inner diameter D i , the length L of the cooling region, the heat convection coefficient h and the heat conduction coefficient K of the catheter wall. For example, for a catheter with an outer diameter of 0.130 inch, an inner diameter of 0.126 inch, an outer tube made of Pebax and a cooling region length of 10 cm, when placed in the internal carotid artery for low pressure induced phase change cooling, assuming the blood flow is 300 mL / min, when the injection flow rate of the cooling medium is 1 mL / min, the equivalent cooling power is about 41 W, and the blood flowing through the catheter at 37℃ is cooled to about 35℃, at which time the temperature of the outer wall of the catheter is about -11℃. Therefore, in this operating environment, an anti-coagulation layer as described above needs to be provided on the outer surface of the tube body 2. In some embodiments, a temperature sensor can be installed on the outer surface of the distal end of the tube body 2 to detect the temperature of the cooled blood.

[0154] In some embodiments, the vacuum source further comprises a pressure sensor and a pressure control device. When it is necessary to increase the cooling power, the vacuum source can further decrease the pressure in the vacuum cavity 41. In other embodiments, the vacuum source further comprises a timing function to maintain cooling for a predetermined treatment time.

[0155] In some embodiments, the cooling medium delivery device further comprises a flow control device to increase the injection flow rate of the cooling medium when it is necessary to increase the cooling power. In other embodiments, the flow control device further comprises a timing function to maintain cooling for a predetermined treatment time.

[0156] In some examples, the outer surface of the cooling medium injection tube 22 can be provided with a hydrophilic coating for reducing the contact angle between the cooling medium and the outer surface of the cooling medium injection tube 22, so as to increase the gasification area of the cooling medium and improve the cooling efficiency. The hydrophilic coating can be one or more of polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, polyethylene imine, polyacrylamide, polyacrylic acid or polysaccharide materials commonly used in vascular intervention catheter hydrophilic coating. Similarly, the number of injection holes 221 provided on the cooling medium injection tube 22 can also be increased to increase the gasification area of the cooling medium so as to improve the cooling efficiency.

[0157] In some examples, the injection extension tube 3, the vacuum extension tube 4 and the main cavity extension tube 5 can be respectively provided with external threads or internal threads luer connectors for quick fluid connection and disconnection with a vacuum source, a cooling medium delivery device and other commonly used hemostatic valves and the like.

[0158] The following describes the operation steps of the catheter for low-temperature brain protection according to the present application by taking physiological saline as the cooling medium. In use, the catheter body 2 is sent to the carotid artery or a position further away from the intracranial blood vessel through the blood vessel by a guide wire and a microcatheter in the main intervention tube 21. When low-temperature brain protection is needed, the vacuum extension tube 4 is first connected to a vacuum source, and a negative pressure is set to maintain the pressure in the vacuum cavity 41 to be less than 6 kPa. Then, the cooling medium delivery device is connected to the injection extension tube 3, and the input flow of the cooling medium is set. The physiological saline is delivered to the injection tube 22, and enters the vacuum cavity 41 through the injection holes 221. Under the action of the negative pressure, the physiological saline is gasified in the vacuum cavity 41 located at the distal end 202 of the catheter, and the heat of the blood around the catheter body 2 is taken away, so as to achieve local brain cooling.

[0159] In some examples, the temperature of the cooled blood can be monitored by a temperature sensor located at the distal end of the catheter body 2, and the injection flow of the cooling medium and the negative pressure of the vacuum source can be adjusted in real time. When the temperature of the blood is lower than a preset value, the injection amount of the cooling medium is reduced or the pressure of the vacuum source is increased or both; when the temperature of the blood is higher than the preset value, the injection amount of the cooling medium is increased or the pressure of the vacuum source is reduced or both.

[0160] The present application can be used to protect the brain nerves of stroke patients, and has the advantages of high cooling efficiency, simple operation, safety and reliability and the like.

[0161] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer” and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0162] The specific embodiments of the present application have been described. It is to be understood that the application is not limited to particular details described herein and that various modifications can be made therein without departing from the scope of the claimed application. Embodiments and features disclosed in this document, including in the examples, can be combined with each other, unless specifically contradicted by or inconsistent with each other.

Claims

1. A vascular intervention catheter for brain protection, characterized in that, The application relates to a catheter, which comprises a catheter seat (1), a catheter body (2), an injection epitaxy tube (3) and a vacuum epitaxy tube (4). One end of the catheter body (2) is connected with one end of the catheter seat (1), and the injection epitaxy tube (3) and the vacuum epitaxy tube (4) are arranged on the catheter seat (1). A main intervention tube (21), a cooling medium injection tube (22) and a vacuum cavity (41) are arranged in the catheter body (2); the main intervention tube (21) extends along the axial direction of the catheter body (2), the vacuum cavity (41) is formed between the outer side wall of the main intervention tube (21) and the inner side wall of the catheter body (2), and a main intervention cavity (211) is arranged in the main intervention tube (21). The vacuum cavity (41) is communicated with the vacuum epitaxy tube (4), and the injection epitaxy tube (3) is communicated with the vacuum cavity (41) through the cooling medium injection tube (22). Cooling medium is injected from outside the body through the injection epitaxy tube (3), is transported into the vacuum cavity (41) through the cooling medium injection tube (22), spontaneously changes phase in the vacuum cavity (41), and carries away the heat of blood flow around the catheter by using the phase change. The two ends of the catheter body (2) are respectively a proximal end (201) and a distal end (202). The proximal end (201) is connected with the catheter seat (1), one end of the cooling medium injection tube (22) is communicated with the injection epitaxy tube (3), and the other end of the cooling medium injection tube (22) is located in the vacuum cavity (41) at the position of the distal end (202). Cooling medium is injected from outside the body through the injection epitaxy tube (3), is transported into the vacuum cavity (41) at the position of the distal end (202) through the cooling medium injection tube (22). The distal end (202) is provided with a distal end sealing ring (23), and the distal end sealing ring (23) is located between the outer side wall of the main intervention tube (21) and the inner side wall of the catheter body (2). A vacuum sealing ring (24) is arranged in the catheter seat (1) and is located between the outer side wall of the main intervention tube (21) and the inner side wall of the catheter seat (1) and is adjacent to the vacuum epitaxy tube (4). The cavity space between the distal end sealing ring (23) and the vacuum sealing ring (24) is the vacuum cavity (41). The main intervention tube (21) extends into the catheter seat (1).

2. The catheter for neuroprotection for vascular interventions according to claim 1, characterized in that, An injection buffer cavity (31) is arranged in the catheter seat (1) and is formed between the outer side wall of the main intervention tube (21) and the inner side wall of the catheter seat (1). The injection epitaxy tube (3) is communicated with the injection buffer cavity (31), and the injection buffer cavity (31) is communicated with the vacuum cavity (41) through the cooling medium injection tube (22). An injection sealing ring (25) is arranged in the catheter seat (1) and is located between the outer side wall of the main intervention tube (21) and the inner side wall of the catheter seat (1) and is adjacent to the injection epitaxy tube (3).

3. The catheter for neuroprotection of a vascular intervention according to claim 2, characterized in that, ​ The cavity space between the vacuum sealing ring (24) and the injection sealing ring (25) is the injection buffer cavity (31).

4. The catheter for neuroprotection for vascular interventions according to claim 3, characterized in that, The vascular intervention catheter further comprises a main cavity extension tube (5); The main cavity extension tube (5) is connected to the other end of the catheter seat (1).

5. The catheter for neuroprotection of a vascular intervention according to claim 4, characterized in that, The size of the main intervention cavity (211) is suitable for accommodating a guide wire, a microcatheter and an intermediate catheter; And / or, the material of the distal end sealing ring (23), the vacuum sealing ring (24) and the injection sealing ring (25) is one or more of silicone, polyurethane, polytetrafluoroethylene and adhesive; And / or, the cooling medium injection tube (22) is provided with one or more injection holes (221) on the tube body at the position of the distal end (202); the distal end (202) is provided with a developing ring, which is arranged in the axial position of the injection hole (221); And / or, the outer surface of the cooling medium injection tube (22) at the position of the distal end (202) is provided with a hydrophilic coating; the hydrophilic coating is one or more of polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, polyethylene imine, polyacrylamide, polyacrylic acid or polysaccharide material.

6. The catheter for neuroprotection of a vascular intervention according to claim 4, characterized in that, The cooling medium includes normal saline; the pressure maintained in the vacuum cavity (41) can reduce the boiling point of the cooling medium to below physiological temperature; And / or, the material of the cooling medium injection tube (22) is PEEK; And / or, the tube body (2) is provided with a temperature sensor at the position of the distal end (202), which is used to monitor the local temperature; And / or, the outer surface of the tube body (2) is provided with an anticoagulant layer; the anticoagulant layer is one of heparin, citrate and hydrogel; And / or, the inner and outer surfaces of the distal end (202) are provided with a textured structure, which is used to increase the surface area to improve the heat transfer efficiency.

7. The catheter for vascular interventions for brain protection according to claim 4, characterized in that, The catheter seat (1) is provided with a first outer threaded luer connector and a first inner threaded luer connector; The injection extension tube (3) and the vacuum extension tube (4) are provided with a second inner threaded luer connector for connecting the first outer threaded luer connector; The main cavity extension tube (5) is provided with a second outer threaded luer connector for connecting the first inner threaded luer connector.

8. An intravascular cooling system for brain protection, characterized by The vascular intervention catheter for brain protection according to any one of claims 1 to 7; Further comprising a cooling medium delivery device and a negative pressure device; The cooling medium delivery device communicates with the cooling medium injection tube (22) through the injection extension tube (3); The negative pressure device communicates with the vacuum cavity (41) through the vacuum extension tube (4); The cooling medium injection tube (22) and the vacuum cavity (41) are fluidly connected at the distal end (202) of the tube body (2); The main intervention tube (21) is fluidly isolated from the cooling medium injection tube (22) and the vacuum cavity (41); The cooling medium injection tube (22) and the vacuum cavity (41) are fluidly isolated from the blood outside the catheter.

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