Closable hemodiafiltration catheter

Abstract

The utility model belongs to the technical field of medical instruments, and particularly relates to a closable hemodialysis filtration catheter which is mainly used for being placed in the body of a patient temporarily or for a long time to carry out hemodialysis / filtration on the patient. The artery branch tube is used for leading out artery blood; the vein branch tube is used for sending back dialyzed and filtered blood from veins of a patient; wherein a first closing element is arranged in the artery branch pipe first hole, a second closing element is arranged in the vein branch pipe second hole, the first closing element is constructed to be capable of closing the artery branch pipe first hole, and the second closing element is constructed to be capable of closing the vein branch pipe second hole; the hemodialysis / filtration catheter mainly solves the problems that an opening of an existing hemodialysis / filtration catheter is located in a blood vessel, blood enters the catheter from the opening, thrombus is easily formed in the catheter opening, and the thrombus falls off and enters the circulation risk. When an anticoagulant drug solution is used for sealing, the anticoagulant drug enters circulation, and the blood coagulation function of the patient is affected.

Description

Technical Field

[0001] The utility model belongs to the technical field of medical devices, and in particular relates to a closable hemodialysis filtration catheter. Background Art

[0002] At present, temporary or long-term venous catheters used in clinical hemodialysis and hemofiltration (CRRT) are double-lumen tubes, divided into arterial and venous ends, which respectively draw blood out of / return to the body during dialysis or hemofiltration. During the dialysis / hemofiltration interval, the catheter needs to be sealed with an anticoagulant solution. Currently, sodium heparin or sodium citrate is commonly used for sealing in clinical practice. Since the opening of the catheter is located in the blood vessel, blood can easily enter the catheter through the opening, and the inner wall of the catheter in contact with blood can easily cause the following problems:

[0003] 1. The catheter port is prone to thrombosis, which affects the service life of the catheter and even has the risk of thrombosis falling off and entering the circulation;

[0004] 2. Anticoagulant drugs enter the circulation and affect the patient's coagulation function, which may cause bleeding events in severe cases.

[0005] In view of the above problems, the utility model provides a closable hemodiafiltration catheter. Utility Model Content

[0006] In order to overcome the problems raised in the background technology, the utility model adopts the following technical solutions:

[0007] A closable hemodialysis / filtration catheter, comprising:

[0008] An arterial branch tube, used for drawing out arterial blood; the arterial branch tube has a first distal end and a first hole that are connected to each other, wherein the first hole is used for introducing arterial blood into the arterial branch tube;

[0009] A venous branch tube is used to return the dialyzed and filtered blood from the patient's vein; the venous branch tube has a second distal end, a second hole and a tip hole that are connected to each other; the venous branch tube and the arterial branch tube are adjacent to each other and are not connected to the arterial branch tube, wherein the dialyzed and filtered blood is returned to the body through the second hole and the tip hole;

[0010] A first sealing element, disposed in the arterial branch; wherein the first sealing element is configured to seal the first hole of the arterial branch;

[0011] A second sealing element is disposed in the venous branch, wherein the second sealing element is configured to seal the second hole and the tip hole of the venous branch.

[0012] In some embodiments of the present application, the first hole is formed in the free wall of the arterial branch, and the second hole is formed in the free wall of the venous branch.

[0013] In some embodiments of the present application, there is a distance between the first hole and the second hole, wherein the first hole and the second hole are in opposite directions.

[0014] In some embodiments of the present application, the first hole is configured as a port for the arterial branch to enter one end of the blood vessel, wherein the first hole and the first distal end correspond to each other;

[0015] The tip hole is configured as a port for the venous branch to enter one end of the blood vessel, wherein the tip hole and the second distal end correspond to each other, the second hole is located between the tip hole and the second distal end, and the second hole is close to the tip hole.

[0016] In some embodiments of the present application, the first closing element comprises:

[0017] a first balloon, the first balloon being disposed on the inner wall of the arterial branch, wherein the first balloon has an expanded state and a contracted state, and in the expanded state, the first hole is closed;

[0018] A first connecting tube is partially attached to the inner wall of the arterial branch, wherein the first connecting tube has a first end and a second end opposite to each other, the first end is connected to the first balloon, and the second end passes through the wall of the arterial branch and extends out of the arterial branch;

[0019] A joint is disposed at the second end of the first connecting tube, wherein the joint is configured to control the balloon to switch between the expanded state and the contracted state.

[0020] Furthermore, the first bag body includes: one of a water bag and an air bag.

[0021] Further, the first bladder is configured as a water bladder.

[0022] Furthermore, a one-way valve is arranged in the connector, wherein the one-way valve is configured to allow fluid to flow in both directions when the syringe head is inserted, and after the syringe is pulled out, the valve is closed, and the fluid can only flow from the connector to the balloon, and reverse flow is not allowed, so that the balloon remains in an expanded state.

[0023] Furthermore, the joint also has a sealing cap, wherein the sealing cap is detachably connected to the joint.

[0024] In some embodiments of the present application, the second closing element comprises:

[0025] a second balloon, the second balloon being disposed on the inner wall of the venous branch, wherein the second balloon has the same structure as the first balloon;

[0026] a third sac, which is disposed on the inner wall of the venous branch and is used to close the tip hole;

[0027] The second connecting tube is partially disposed on the inner wall of the venous branch, and the length of the second connecting tube is greater than the length of the first connecting tube; wherein the second connecting tube connects the second capsule and the third capsule in series.

[0028] Beneficial effects of the utility model:

[0029] 1. When placing the catheter, use the Seldinger technique to percutaneously place the catheter (including the arterial branch and the venous branch) into the central vein of the human body through a guide wire. During treatment, the first closure element and the second closure element capsule are in a contracted state, so that the arterial branch and the venous catheter lumen remain unobstructed, and the patient's blood is drawn out through the arterial branch, and after passing through the hemodialysis / filtration filter and the extracorporeal tubing, it is returned to the patient's body through the venous branch; after the treatment, the first hole of the arterial branch and the second hole and the tip hole of the venous branch can be closed by the first closure element and the second closure element; in this way, blood can be prevented from entering the arterial branch and the venous branch without hemodialysis / filtration; in this way, blood can be prevented from forming thrombi in the arterial branch and the venous branch.

[0030] 2. By setting the first closing element and the second closing element, the arterial branch and the venous branch are closed. Compared with the traditional sealing method, the use of anticoagulant drug solution is saved, and the anticoagulant drugs are prevented from entering the circulation and affecting the patient's coagulation function. In severe cases, it may cause the risk of bleeding events. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0032] Figure 2 This is a schematic diagram of the structure of the arterial branch and the venous branch of the utility model;

[0033] Figure 3 It is a schematic diagram of the internal structure of the first proximal end and the second proximal end of the utility model;

[0034] Figure 4 This is a schematic diagram of the structure of the first capsule and the second capsule of the utility model;

[0035] Figure 5 This is a schematic diagram of the utility model after the first hole and the second hole are closed;

[0036] Figure 6This is a schematic diagram of the structure of the first capsule of the utility model arranged along the first hole;

[0037] Figure 7 This is a schematic diagram of another implementation of the first capsule and the second capsule of the utility model;

[0038] Figure 8 This is a schematic diagram of the joint structure of the utility model;

[0039] Fig. 9 This is a schematic diagram of the internal structure of the connector of the utility model;

[0040] Fig.10 This is a schematic diagram of another implementation of the arterial branch tube and the venous branch tube of the utility model;

[0041] Fig.11 This is a schematic diagram of the positions of the first hole and the second hole of the utility model;

[0042] Fig.12 This is a schematic diagram of the position structure of the first capsule and the second capsule of the utility model;

[0043] Fig.13 This is a schematic diagram of the pipe structure of the utility model;

[0044] In the figure, 1, arterial branch; 11, first distal end; 12, first hole; 13, first balloon; 14, connecting tube; 15, joint; 151, channel; 1511, sleeve; 1512, through hole; 152, one-way valve; 153, sealing cap; 2, venous branch; 21, second distal end; 22, second hole; 221, tip hole; 23, second balloon; 24, third balloon; 3, catheter clamp; 4, tube body. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the utility model are clearly and completely described below through specific embodiments. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Those skilled in the art can easily understand other advantages and functions of the utility model from the contents disclosed in this specification. The utility model can also be implemented or applied through other different specific implementation methods. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0046] Figure 1 —4 shows the main technical content of this embodiment. This specific embodiment provides a closable hemodiafiltration catheter, which includes:

[0047] The arterial branch tube 1 is used to draw out the blood in the blood vessel; the arterial branch tube 1 has a first distal end 11 and a first hole 12 which are connected to each other, wherein the first hole 12 is used to draw the blood in the blood vessel into the arterial branch tube 1; the first hole 12 is located on the free wall of the arterial branch tube 1, wherein the first hole 12 can be set as one or more, and when the first hole 12 is set as multiple, each first hole 12 is arranged along the extension direction of the arterial branch tube 1;

[0048] The venous branch 2 is used to return the blood after passing through the extracorporeal filter and the pipeline to the blood vessel; the venous branch 2 has a second distal end 21, a second hole 22 and a tip hole 221 that are connected to each other; the venous branch 2 and the arterial branch 1 are partially adjacent to each other and share an inner wall, and the venous branch 2 is not connected to the arterial branch 1, wherein the dialyzed and filtered blood is returned through the second hole 22 and the tip hole 221; similarly, the second hole 22 can be set to one or more, and when the second hole 22 is set to multiple, each second hole is arranged along the extension direction of the venous branch 2; and the tip hole 221 is used to pass the guide wire when the catheter is placed.

[0049] A first sealing element is disposed in the arterial branch 1; wherein the first sealing element is configured to seal the first hole 12 of the arterial branch 1;

[0050] The second sealing element is disposed in the venous branch 2 , wherein the second sealing element is configured to seal the second hole 22 and the tip hole 221 of the venous branch 2 .

[0051] It should be noted that, when this embodiment is used, the catheter (including the arterial branch 1 and the venous branch 2) is percutaneously placed into the patient's central vein (internal jugular vein / femoral vein, etc.). The first distal end 11 of the arterial branch 1 and the second distal end 21 of the venous branch 2 are both externally connected to the hemodialysis / filtration extracorporeal pipeline; the blood is led out of the patient's body through the arterial branch 1 through the first hole 12, and after the blood is dialyzed / filtered by the hemodialysis / filtration instrument, it is then sent back to the patient's blood vessels through the venous branch 2 through the second hole 22 and the tip hole 221.

[0052] refer to Figure 1 —3. In the present embodiment, the first distal end 11 of the arterial branch 1 and the second distal end 21 of the venous branch 2 are separated from each other. This arrangement facilitates the connection of the arterial branch 1 and the venous branch 2 to a hemodialysis / filtration instrument, wherein the first distal end 11 of the arterial branch 1 and the second distal end 21 of the venous branch 2 are at the same distance from their intersection, so that at least a portion of the arterial branch 1 and the venous branch 2 are integrally connected.

[0053] refer to Figure 2—4. In the present embodiment, the first hole 12 is formed on the outer wall of the arterial branch 1, i.e., the free wall (i.e., the outer wall of the arterial branch 1), and the second hole 22 is formed on the outer wall of the venous branch 2, i.e., the free wall (i.e., the outer wall of the venous branch 2), and the tip hole 221 is the tip opening of the venous branch 2, or the first hole 12 is configured as a port at one end of the arterial branch 1 entering the human body, wherein the first hole 12 and the first distal end 11 correspond to each other; the second hole 22 / tip hole 221 is configured as a port at one end of the venous branch 2 entering the human body, wherein the second hole 22 / tip hole 221 and the second distal end 21 correspond to each other.

[0054] refer to Figure 3 —4, wherein, when the first hole 12 is formed on the outer wall of the arterial branch 1 and the second hole 22 is formed on the outer wall of the venous branch 2, the arterial branch 1 also has a first proximal end that can be in a sealed / unobstructed state, the first hole 12 is close to the first proximal end, and the venous branch 2 also has a second proximal end that can be in a closed / unobstructed state, and the tip hole 221 and the second hole 22 are close to the second proximal end; wherein, the first proximal end and the second proximal end form a tip, the tip hole 221 is connected to the blood through the catheter tip, and the catheter tip is conical.

[0055] When placing the catheter, the Seldinger technique is used to push the dialysis / filtration catheter into the patient's blood vessel through the tip hole 221 and the venous branch 2 along the metal guide wire pre-placed in the target blood vessel.

[0056] refer to Figure 4 More specifically, there is a distance between the first hole 12 and the second hole 22, wherein the distance between the first hole 12 and the tip hole 221 is greater than the distance between the second hole 22 and the tip hole 221. Preferably, the direction of the first hole 12 is opposite to that of the second hole 22.

[0057] refer to Figure 2 —5. In the present embodiment, the first closing element comprises: a first balloon 13, a first connecting tube 14 and a connector 15, wherein the first balloon 13 is arranged on the inner wall of the arterial branch 1, wherein the first balloon 13 has an expanded state and a contracted state; the first connecting tube 14 is partially attached to the inner wall of the arterial branch 1, wherein the first connecting tube 14 has a first end and a second end opposite to each other, the first end is connected to the first balloon 13, and the second end passes through the wall of the arterial branch 1 and extends out of the arterial branch 1; the connector 15 is arranged at the second end of the connecting tube 14, wherein the connector 15 is constructed to control the first balloon 13 to switch between the expanded state and the contracted state.

[0058] refer to Figure 3—5. More specifically, the first balloon 13 is configured to completely close the first hole 12 in the expanded state, and a small part of the first balloon 13 protrudes out of the first hole 12 in the expanded state, or the first balloon 13 is configured to be flush with the outer wall of the arterial branch 1 in the expanded state, so as to completely isolate the blood outside the arterial branch 1 and prevent blood from entering the arterial branch 1.

[0059] refer to Figure 1 —3 and Figure 8 —9, more specifically, the connector 15 has a channel 151, which is connected to the connecting tube 14, and a one-way valve 152 is arranged in the channel 151. The one-way valve 152 is configured to allow fluid / gas to flow in two directions between the connector 15 and the first capsule 13 when the syringe connector 15 is inserted; in actual application, after a dialysis / hemofiltration treatment is completed, a sterile saline / air with an amount equal to the volume of the arterial branch 1 is first injected into the arterial branch 1 through the distal end of the arterial branch 1, and then Afterwards, the arterial branch 1 is clamped, and then a syringe is used to inject physiological saline or air into the first sac 13 through the joint 15 through the hole 151, so that the first sac 13 expands to close the first hole 12 of the arterial branch 1; after the syringe is withdrawn, the one-way valve 152 and the sealing cap 153 work together to ensure that the fluid in the first sac 13 does not flow back / leak, so that the first sac 13 continues to expand to close the arterial branch 1, and the physiological saline in the arterial branch 1 is blocked from the blood, achieving an anti-thrombotic effect. It can ensure that the arterial branch 1 is closed when the patient is not undergoing hemodialysis / filtration, so as to avoid the formation of thrombus at the first proximal end of the arterial branch 1.

[0060] refer to Figure 2 and Figure 8 —9. In the present embodiment, the connector 15 further comprises a sealing cap 153, wherein the sealing cap 153 and the connector 15 are detachably connected; more specifically, the sealing cap 153 and the connector 15 are threadedly connected. When in use, the sealing cap 153 and the connector 15 are connected by screwing. When in use, but the patient does not need hemodialysis / filtration, the sealing cap 153 is screwed onto the connector 15 to prevent foreign matter from adhering to the connector 15, thereby preventing foreign matter from entering the connecting tube 14 or the first capsule 13 when the connector 15 is used to convert the first capsule 13 into an expanded state, thereby extending the service life of the catheter.

[0061] refer to Figure 4 —5 and Figure 8—9. In this embodiment, the sac is constructed as one of a water sac and an air sac. When the sac is in a contracted state, the sac is attached to the inner wall of the arterial branch 1 and is opposite to the first hole 12, so that the arterial branch 1 always has a larger inner diameter, which is convenient for blood circulation. More specifically, when the sac is constructed as a water sac, the connector 15 can be externally connected to a syringe containing sterile saline, and the syringe is used to push liquid into the sac through the connecting tube 14, so as to realize the conversion of the sac from a contracted state to an expanded state. When the sac is constructed as an air sac, the connector 15 can be externally connected to a syringe containing sterile saline, and the syringe is used to push liquid into the sac through the connecting tube 14, so as to realize the conversion of the sac from a contracted state to an expanded state. The head 15 can be externally connected to a syringe that inhales air or inert gas to inject gas into the balloon, thereby converting the balloon from a contracted state to an expanded state. Furthermore, it should be noted that when using a syringe to push liquid or push gas, its one-way valve 152 is in an open state; after the pushing action is completed, the one-way valve 152 is reset, so that the balloon can always remain in an expanded state; preferably, the first balloon 13 is a water bag, and sterile saline is pushed into it when in use, so as to avoid the formation of air embolism after the first balloon 13 ruptures.

[0062] refer to Figure 4 —5 and Fig. 9 More specifically, a sleeve 1511 is slidably arranged in the channel 151, wherein the sleeve 1511 has a plurality of through holes 1512. When in use, a syringe containing sterile saline or a syringe inhaling air or inert gas is plugged into the channel 151. At this time, the interface end of the syringe is against one end of the sleeve 1511, so that the sleeve 1511 slides in the channel 151, so that the other end of the sleeve 1511 pushes the one-way valve 152 open, and at this time, the sterile saline or gas in the syringe can pass through the sleeve 1511. The liquid or gas in the first sac 13 is pushed into the through hole 1512 of the sleeve 1511, so that the first sac 13 is converted from a contracted state to an expanded state; when the first sac 13 is converted from an expanded state to a contracted state, similarly, an empty syringe is inserted into the channel 151, so that the interface end of the syringe is against one end of the sleeve 1511, and the one-way valve 152 is pushed open. At this time, the liquid or gas in the first sac 13 can be extracted through the through hole 1512 on the sleeve 1511, so that the first sac 13 is converted to a contracted state, and then the patient is subjected to hemodialysis / filtration.

[0063] refer to Figure 4 and Figure 6—7. In the present embodiment, the second closing element is different from the first closing element in that the second closing element includes a second capsule 23 for closing the second hole 22, a third capsule 24 for closing the tip hole 221, and a second connecting tube 14 connecting the second capsule 23 and the third capsule 24 in series; more specifically, the second connecting tube 14 included in the second closing element passes through the wall of the venous branch 2, and the passing position is mirrored to the passing position of the first connecting tube 14 included in the first closing element on the wall of the arterial branch 1.

[0064] More specifically, the second closing element includes a second balloon 23 and a third balloon 24. In the expanded state, a small portion of the second balloon 23 extends out of the second hole 22 or is flush with the outer wall of the venous branch 2 in the expanded state, while the third balloon 24 completely closes the tip hole 221.

[0065] It should be noted that after dialysis / hemofiltration treatment, sterile saline is used to fill the arterial branch 1 and the venous branch 2, and then the balloons in the arterial branch 1 and the venous branch 2 are converted to an expanded state to avoid blood residue in the arterial branch 1 and the venous branch 2.

[0066] In other embodiments (not shown), the shape of the first hole 12 is one of a circle, a rhombus, and a parallelogram, and the first capsule 13 is arranged along the edge of the first hole 12, wherein the first capsule 13 is configured to be able to completely fill the first hole 12 in an expanded state, and when the first capsule 13 is in a contracted state, the first hole 12 is in an open state, at this time, the patient's blood can enter the arterial branch 1 through the first hole 12, thereby achieving the blood being drawn out from the arterial branch 1, and when the first capsule 13 is in an expanded state, the first hole 12 is completely filled with the capsule, thereby isolating the blood outside the arterial branch 1, thereby preventing blood from entering the arterial branch 1 to form a thrombus.

[0067] Similarly, the shape of the second hole 22 is the same as that of the first hole 12; the second capsule 23 is arranged along the edge of the second hole 22, and then in the expanded state, the second capsule 23 closes the second hole 22, while the arrangement of the third capsule 24 remains unchanged, and the third capsule 24 is flush with the tip hole 221 in the expanded state.

[0068] refer to Figure 1 —4 and Fig.10In this embodiment, catheter clamps 3 are respectively provided near the first distal end 11 of the arterial branch 1 and near the second distal end 21 of the venous branch 2, wherein the two catheter clamps 3 respectively cut off the first distal end 11 of the arterial branch 1 and the first hole 12, and cut off the second distal end 21 of the venous branch 2 and the second hole 22. At the end of the treatment, after the arterial branch 1 and the venous branch 2 are filled with sterile saline, the two catheter clamps 3 are used to cut off the first distal end 11 of the arterial branch 1 and the first hole 12, and the second distal end 21 of the venous branch 2 and the second hole 22, and then the three balloons are changed from a contracted state to an expanded state. After the arterial branch 1 and the venous branch 2 are sealed, the catheter clamps 3 are released, and the first distal end 11 and the second distal end 21 are sealed.

[0069] refer to Fig.10 —12. In another embodiment, the first hole 12 is configured as a port for the arterial branch 1 to enter one end of the human body, wherein the first hole 12 and the first distal end 11 are opposite to each other; the second hole 22 is configured as a port for the venous branch 2 to enter one end of the human body, wherein the second hole 22 and the second distal end 21 are opposite to each other.

[0070] More specifically, the length of the arterial branch 1 is shorter than that of the venous branch 2 . At this time, the end of the arterial branch 1 entering the human body is located on the outer wall of the venous branch 2 , so that there is a distance between the first hole 12 and the second hole 22 .

[0071] Herein, the first balloon 13 is arranged along the edge of the first hole 12, and the first balloon 13 is located in the arterial branch 1, wherein the first balloon 13 has a certain length and extends from the inner wall of the arterial branch 1 toward the first distal end 11; more specifically, the length of the first balloon 13 can be about 1 cm; and in the venous branch 2, the second balloon 23 included in the second closing element, similarly, extends from the inner wall of the venous branch 2 toward the second distal end 21, so that the venous branch 2 is closed in the expanded state.

[0072] At the end of the treatment, similarly, the arterial branch 1 and the venous branch 2 are first filled with sterile saline, and then the balloons in the arterial branch 1 and the venous branch 2 are converted to an expanded state, thereby sealing the arterial branch 1 and the venous branch 2.

[0073] In addition, this embodiment can also be set as a single-cavity structure, wherein, in this setting, the tube body 4 has a pointed end, and the pointed end has a circular hole for blood circulation, wherein the capsule is arranged in the circular hole of the pointed end, and the same connecting tube 14 is arranged on the inner wall of the tube body 4 and passes through near the distal end of the tube body 4, and the connecting tube 14 also has a joint 15; in addition, a catheter clamp 3 is also arranged near the distal end of the tube body 4.

[0074] In addition, refer to Fig.13 , this embodiment includes but is not limited to the configuration shown in the figure when implemented.

[0075] The use of the utility model:

[0076] 1. When placing the catheter, the Seldinger technique is used to push the dialysis / filtration catheter into the patient's blood vessels through the tip hole and the venous branch along the metal guide wire pre-placed in the target blood vessel. The catheter is fixed to the skin by suturing;

[0077] 2. When performing hemodialysis / filtration for a patient, the first distal end of the arterial branch and the second distal end of the venous branch are connected to an external hemodialysis / filtration instrument; the patient's blood is drawn out from the arterial branch, and after being dialyzed / filtered, is sent back into the patient's body through the venous branch;

[0078] 3. After completing the hemodialysis / filtration for the patient, first fill the arterial branch and the venous branch with sterile saline, and then respectively close the first distal end of the arterial branch and the second distal end of the venous branch with a catheter clamp; connect the syringe that has sucked sterile saline to the connector, so as to push liquid into the first closing element and the second closing element to close the arterial branch and the venous branch;

[0079] 4. After the arterial branch and the venous branch are sealed, the joint between the first sealing element and the second sealing element is sealed with a sealing cap.

[0080] The above-mentioned embodiments are only used to understand the present invention. It should be noted that, for those skilled in the art, several improvements can be made to the present invention without departing from the principle of the present invention, and these improvements will also fall within the scope of protection of the claims of the present invention.

Claims

1. A closable hemodiafiltration catheter, It is characterized in that It includes: An arterial branch tube, used for drawing out arterial blood; the arterial branch tube has a first distal end and a first hole that are connected to each other, wherein the first hole is used for introducing arterial blood into the arterial branch tube; A venous branch tube is used to return the dialyzed and filtered blood from the patient's vein; the venous branch tube has a second distal end, a second hole and a tip hole that are connected to each other; the venous branch tube and the arterial branch tube are adjacent to each other and are not connected to the arterial branch tube, wherein the dialyzed and filtered blood is returned to the body through the second hole and the tip hole; A first sealing element, disposed in the arterial branch; wherein the first sealing element is configured to seal the first hole of the arterial branch; A second sealing element is disposed in the venous branch, wherein the second sealing element is configured to seal the second hole and the tip hole of the venous branch.

2. The closable hemodiafiltration catheter according to claim 1, It is characterized in that The first hole is formed on the outer wall of the arterial branch, and the second hole is formed on the outer wall of the venous branch.

3. The closable hemodiafiltration catheter according to claim 2, It is characterized in that There is a distance between the first hole and the second hole, wherein the first hole and the second hole are in opposite directions.

4. The closable hemodiafiltration catheter according to claim 1, It is characterized in that The first hole is configured as a port for the arterial branch tube to enter one end of the blood vessel, wherein the first hole and the first distal end correspond to each other; The tip hole is configured as a port for the venous branch to enter one end of the blood vessel, wherein the tip hole and the second distal end correspond to each other, the second hole is located between the tip hole and the second distal end, and the second hole is close to the tip hole.

5. The closable hemodiafiltration catheter according to any one of claims 2 to 4, It is characterized in that The first closing element comprises: A first balloon, the first balloon being disposed on the inner wall of the arterial branch, wherein the first balloon has an expanded state and a contracted state, and in the expanded state, the first hole is closed; A first connecting tube is partially attached to the inner wall of the arterial branch, wherein the first connecting tube has a first end and a second end opposite to each other, the first end is connected to the first balloon, and the second end passes through the wall of the arterial branch and extends out of the arterial branch; A joint is disposed at the second end of the first connecting tube, wherein the joint is configured to control the balloon to switch between the expanded state and the contracted state.

6. The closable hemodiafiltration catheter according to claim 5, It is characterized in that The first bag body includes: one of a water bag and an air bag.

7. The closable hemodiafiltration catheter according to claim 6, It is characterized in that The first bladder is configured as a water bladder.

8. The closable hemodiafiltration catheter according to claim 5, It is characterized in that A one-way valve is arranged in the connector, wherein the one-way valve is arranged to allow the fluid to flow in both directions when the syringe head is inserted, and when the syringe is pulled out, the one-way valve is closed, and the fluid can only flow from the connector to the balloon, and reverse flow is not allowed, so that the balloon remains in an expanded state.

9. The closable hemodiafiltration catheter according to claim 5, It is characterized in that The joint further comprises a sealing cap, wherein the sealing cap is detachably connected to the joint.

10. The closable hemodiafiltration catheter according to claim 5, It is characterized in that The second closing element comprises: a second balloon, the second balloon being disposed on the inner wall of the venous branch, wherein the second balloon has the same structure as the first balloon; a third sac, which is disposed on the inner wall of the venous branch and is used to close the tip hole; A second connecting tube is partially attached to the inner wall of the venous branch, and the length of the second connecting tube is greater than the length of the first connecting tube; wherein the second connecting tube connects the second capsule and the third capsule in series.

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