ECMO catheter capable of temporarily blocking blood flow

Abstract

The ECMO catheter capable of temporarily blocking the blood flow comprises a catheter body used for being inserted into a blood vessel, the catheter body comprises an outer tube and an inner tube, the outer tube is arranged on the inner tube in a sleeved mode, and the inner wall of the outer tube is tightly attached to and fixed to the inner tube; a blood flow blocking assembly is arranged on the outer tube and comprises a groove formed in the inner side of the tube wall of the outer tube and a liquid injection channel I axially formed in the tube wall of the outer tube, an elastic film is arranged in the groove, the peripheral edge of the elastic film is connected with the groove, one end of the liquid injection channel I is communicated with the groove, and the other end of the liquid injection channel I is communicated with the elastic film. The other end of the liquid injection channel I extends out of the outer pipe and is connected with a liquid injection pipe I, and a valve I is arranged on the liquid injection pipe I; the inner pipe is provided with a notch corresponding to the groove. The device can assist an ECMO patient to be thoroughly separated from ECMO, ECMO machine withdrawal evaluation is facilitated, meanwhile, the device can be restarted after an ECMO machine withdrawal experiment fails, and damage to the patient is not increased.

Description

Technical Field

[0001] The utility model relates to an ECMO catheter capable of temporarily blocking blood flow, belonging to the technical field of medical devices. Background Technique

[0002] Venovenous extracorporeal membrane oxygenation (VA ECMO) has been increasingly used to provide emergency and potentially life-saving support for patients with severe cardiopulmonary failure. Although the number of VA ECMO applications has increased significantly in recent years, a significant proportion of patients still experience deterioration of circulatory function after withdrawal of V-A ECMO support and require re-mechanical assistance treatment. The failure of ECMO weaning implicitly means the withdrawal of life support. Therefore, before performing V-A ECMO withdrawal, it is obvious that careful review and weaning trials should be carried out very carefully. Currently, there are 3 methods for clinical use of ECMO weaning experiments, each with its own advantages and disadvantages, and it is impossible to completely wean from ECMO support.

[0003] Method 1: Conventional ECMO weaning process: It is a low-flow assisted weaning trial, mainly reducing 0.5 L / min BF step by step every 5-10 minutes until at least 1 L / min BF support for 3-5 minutes for evaluation (echocardiogram and hemodynamics); the disadvantage is that ECMO still has a low-flow support effect of 1-1.5 L / min, overestimating left ventricular function and not comprehensively evaluating right ventricular function. When weaning at this flow rate, about 50% of patients are unsuccessful after weaning, mainly because the evaluation of cardiac function cannot be thorough and re-circulatory assistance is required. And this pipeline needs to be set to zero assistance, usually clamped by an external pipeline clamp, but it cannot be clamped for a long time, otherwise it is easy to form blood clots.

[0004] Method 2: Pump-controlled countercurrent weaning process: The shunted blood volume of countercurrent is transfused back into the right atrium through the vein, increasing the preload of the right ventricle and reducing the afterload of the left ventricle. Therefore, PCRTO can better evaluate the recovery of right ventricular function in patients with right heart failure, and the operation is convenient and the safety is high. The disadvantage is that for patients with intracardiac shunts, the PCRTO test should be avoided, and there may be a risk of microemboli flowing back into the left ventricle during the test, leading to embolic stroke.

[0005] Method 3: "Arteriovenous bridge" weaning test method: Install a collateral pipeline between the arteriovenous loop. During the installation process, it is necessary to temporarily stop the ECMO circulation and repeatedly and intermittently clamp the "bridge" to create an intermittent weaning state, and then judge whether weaning can be performed. The disadvantage is that its process is cumbersome, and this kind of weaning test is prone to complications of infection and thrombosis.

[0006] To sum up, the current ECMO weaning methods cannot completely wean the patient from ECMO for a long time. Therefore, there is an urgent need to develop a device that can assist ECMO patients in weaning evaluation, and can be restarted after the weaning experiment fails without increasing patient injury and cost. Summary of the Invention

[0007] The purpose of the present utility model is to propose an ECMO catheter that can temporarily block blood flow in view of the deficiencies existing in the prior art. It can assist ECMO patients to completely separate from ECMO, which is beneficial for conducting weaning assessment. At the same time, it can be restarted after the failure of the weaning experiment without increasing the patient's injury.

[0008] In order to achieve the above purpose, the present utility model adopts the following technical solutions:

[0009] An ECMO catheter that can temporarily block blood flow, which includes a catheter for inserting into a blood vessel. The catheter includes an outer tube and an inner tube. The outer tube is sleeved on the inner tube and the inner wall of the outer tube is tightly fixed to the inner tube. A blood flow blocking component is provided on the outer tube and the blood flow blocking component is located on one side of the interface end of the catheter. The blood flow blocking component includes a groove provided on the inner side of the outer tube wall and a liquid injection channel Ⅰ axially provided in the outer tube wall. An elastic membrane is provided in the groove. The four peripheral edges of the elastic membrane are connected to the groove. One end of the liquid injection channel Ⅰ communicates with the groove. The other end of the liquid injection channel Ⅰ extends out of the outer tube and is connected with a liquid injection tube Ⅰ. A valve Ⅰ is provided on the liquid injection tube Ⅰ. A notch corresponding to the groove is provided on the inner tube.

[0010] The working principle of the above ECMO catheter that can temporarily block blood flow is as follows:

[0011] Insert the catheter into the patient's blood vessel and connect the interface end of the catheter to a blood pump and an ECMO system to establish ECMO for the patient. When the patient needs to conduct ECMO weaning assessment, blood flow blocking of the catheter is required. At this time, after connecting the valve Ⅰ on the liquid injection tube Ⅰ to a liquid injection device such as a syringe, inject physiological saline into the groove through the liquid injection tube Ⅰ and the liquid injection channel Ⅰ. The injected physiological saline causes the elastic membrane to expand. The expanded elastic membrane extends out from the notch of the inner tube and forms a water sac to temporarily block the blood flow flowing through the inner tube. After the assessment is completed, draw out the injected physiological saline through a liquid injection device such as a syringe. Without the action of physiological saline, the elastic membrane automatically retracts into the groove, making the catheter resume unobstructed blood flow. The elastic membrane can be made of high molecular organic elastic materials such as silica gel and polyurethane materials.

[0012] Further, the blood flow blocking assembly further includes a second liquid injection channel axially arranged within the outer tube wall. One end of the second liquid injection channel extends out of the outer tube and is connected to a second liquid injection tube. The other end of the second liquid injection channel extends into the outer tube. The inner tube is provided with liquid injection holes communicating with the second liquid injection channel. A second valve is provided on the second liquid injection tube, and a micro check valve is provided within the second liquid injection channel. The added second liquid injection channel is for injecting physiological saline into the position of the water sac formed by the elastic membrane when blocking blood flow, so as to avoid blood stasis at this position leading to thrombus formation. The specific operation is to connect the second valve on the second liquid injection tube to a liquid injection device such as a syringe and then inject physiological saline during blood flow blocking. The injected physiological saline passes through the second liquid injection tube and the second liquid injection channel and flows into the position of the water sac from the liquid injection holes of the inner tube, stirring the blood at the position of the water sac to avoid its stasis. The micro check valve provided in the second liquid injection channel can prevent blood from flowing out of the second liquid injection channel. At the same time, the second liquid injection channel and the first liquid injection channel are not connected, and it will not affect the liquid injection operation within the first liquid injection channel.

[0013] Further, two blood flow blocking assemblies are symmetrically provided on the outer tube. The liquid injection operation is performed on the two blood flow blocking assemblies simultaneously to form two water sacs within the inner tube, and the two water sacs squeeze each other to completely block the inner tube, effectively blocking blood flow.

[0014] Further, the end of the second liquid injection channel connected to the liquid injection hole is inclined and the included angle with the outer tube is 40° - 50°. This makes the end of the second liquid injection channel connected to the liquid injection hole deviate, and the deviation direction forms a certain included angle with the blood flow direction, which can effectively prevent blood from flowing reversely into the second liquid injection channel from the liquid injection hole.

[0015] Further, protrusions are provided on the four peripheral edges of the notch on the inner tube, and the protrusions are engaged with the grooves. Such a setting can facilitate the fitting of the inner tube and the outer tube, and also facilitate the fixation of the elastic membrane.

[0016] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0017] The utility model has a simple structure and is convenient to operate. An elastic membrane and corresponding liquid injection channels are arranged within the catheter used in the existing ECMO. By injecting physiological saline into the elastic membrane to make it expand and form a water sac within the inner tube, it can temporarily block blood flow, thereby facilitating medical staff to carry out weaning assessment for patients. When the assessment is over, the injected physiological saline can be drawn out to make the elastic membrane retract, and then the blood flow within the catheter is restored to be unobstructed, without increasing the patient's injury. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the initial state diagram of the ECMO catheter that can temporarily block blood flow described in Embodiment 1.

[0019] Figure 2 It is a diagram of the blood flow blocking state of the ECMO catheter that can temporarily block blood flow described in Example 1.

[0020] Figure 3 It is a cross-sectional view of the ECMO catheter that can temporarily block blood flow described in Example 2.

[0021] Figure 4 It is a front view of the ECMO catheter that can temporarily block blood flow described in Example 2.

[0022] Figure 5 It is a diagram of the initial state of the ECMO catheter that can temporarily block blood flow described in Example 3.

[0023] Figure 6 It is a diagram of the blood flow blocking state of the ECMO catheter that can temporarily block blood flow described in Example 3.

[0024] Reference numerals: 1 - outer tube, 2 - inner tube, 3 - interface end, 4 - groove, 5 - injection channel I, 6 - elastic membrane, 7 - injection tube I, 8 - valve I, 9 - protrusion, 10 - injection channel II, 11 - injection hole, 12 - valve II, 13 - micro check valve, 14 - injection tube II (14). Detailed implementation manners

[0025] The following further describes the present utility model in conjunction with the accompanying drawings and embodiments, but the present utility model is not limited to the embodiments. The specific experimental conditions and methods not specified in the following embodiments are usually conventional means well known to those skilled in the art.

[0026] Example 1: As shown in the attached Figure 1 and Figure 2 A kind of ECMO catheter that can temporarily block blood flow, which includes a catheter for inserting into a blood vessel. The catheter includes an outer tube 1 and an inner tube

[0027] The working principle of the ECMO catheter that can temporarily block blood flow in this embodiment is as follows:

[0028] Insert the catheter into the patient's blood vessel, and connect the interface end 3 of the catheter to a blood pump and an ECMO system to establish ECMO for the patient. When ECMO weaning assessment is required for the patient, blood flow blockage of the catheter is needed. At this time, after connecting the valve I 8 on the liquid injection tube I 7 to a liquid injection device such as a syringe, inject normal saline into the groove 4 through the liquid injection tube I 7 and the liquid injection channel I 5. The injected normal saline causes the elastic membrane 6 to expand. The expanded elastic membrane 6 extends out from the notch of the inner tube 2 and forms a water sac to temporarily block the blood flow passing through the inner tube 2. After the assessment is completed, withdraw the injected normal saline through a liquid injection device such as a syringe. Without the action of normal saline, the elastic membrane 6 automatically retracts into the groove 4, making the catheter resume unobstructed blood flow.

[0029] Example 2: As Figure 3 and Figure 4 shown, the difference between the ECMO catheter that can temporarily block blood flow in this embodiment and that in Example 1 is only that the blood flow blocking component further includes a liquid injection channel II 10 axially arranged within the wall of the outer tube 1. One end of the liquid injection channel II 10 extends out of the outer tube 1 and is connected to a liquid injection tube II 14. The other end of the liquid injection channel II 10 extends into the outer tube 1. The inner tube 2 is provided with a liquid injection hole 11 communicating with the liquid injection channel II 10. The liquid injection tube II 14 is provided with a valve II 12, and a micro check valve 13 is arranged in the liquid injection channel II 10. The added liquid injection channel II 10 is used to inject normal saline into the position of the water sac formed by the elastic membrane 6 when blocking blood flow, so as to avoid blood stasis at this position leading to thrombus formation. The specific operation is to connect the valve II 12 on the liquid injection tube II 14 to a liquid injection device such as a syringe and then inject normal saline during blood flow blockage. The injected normal saline passes through the liquid injection tube II 14 and the liquid injection channel II 10 and flows into the position of the water sac from the liquid injection hole 11 of the inner tube 2 to stir the blood at the position of the water sac to avoid its stasis. The micro check valve 13 arranged in the liquid injection channel II 10 can prevent blood from flowing out of the liquid injection channel II 10. At the same time, the liquid injection channel II 10 and the liquid injection channel I 5 are not connected, which will not affect the liquid injection operation in the liquid injection channel I 5. One end of the liquid injection channel II 10 connected to the liquid injection hole 11 is inclined and forms an angle of 45° with the outer tube 1, making one end of the liquid injection channel II 10 connected to the liquid injection hole 11 skewed. The skewed direction forms a certain angle with the blood flow direction, which can effectively prevent blood from flowing reversely into the liquid injection channel II 10 from the liquid injection hole 11.

[0030] Example 3: As Figure 5 and Figure 6As shown, the difference between the ECMO catheter capable of temporarily blocking blood flow in this embodiment and that in Embodiment 2 is only that two blood flow blocking components are symmetrically arranged on the outer tube 1. By performing the liquid injection operation on the two blood flow blocking components simultaneously, two water sacs are formed in the inner tube 2, and the two water sacs squeeze each other to completely block the inner tube 2, effectively blocking the blood flow.

[0031] Embodiment 4: The difference between the ECMO catheter capable of temporarily blocking blood flow in this embodiment and that in Embodiment 3 is only that the end of the liquid injection channel II 10 connected to the liquid injection hole 11 is inclined and the included angle with the outer tube 1 is 40°.

[0032] Embodiment 5: The difference between the ECMO catheter capable of temporarily blocking blood flow in this embodiment and that in Embodiment 3 is only that the end of the liquid injection channel II 10 connected to the liquid injection hole 11 is inclined and the included angle with the outer tube 1 is 50°.

[0033] The present utility model is not limited to the above embodiments. Those skilled in the art can make equivalent deformations or substitutions without departing from the spirit of the present utility model, and these equivalent variations or substitutions are all included in the scope defined by the claims of this application.

Claims

1. An ECMO catheter that can temporarily block blood flow, characterized in that: Comprising a catheter for intravascular insertion, the catheter includes an outer tube (1) and an inner tube (2), the outer tube (1) is sleeved on the inner tube (2) and the inner wall of the outer tube (1) is tightly fixed to the inner tube (2); a blood flow blocking assembly is provided on the outer tube (1) and the blood flow blocking assembly is located on one side of the interface end (3) of the catheter. The blood flow blocking assembly includes a groove (4) provided on the inner side of the wall of the outer tube (1) and an injection channel I (5) axially provided in the wall of the outer tube (1). An elastic membrane (6) is provided in the groove (4), the four peripheral edges of the elastic membrane (6) are connected to the groove (4), one end of the injection channel I (5) communicates with the groove (4), the other end of the injection channel I (5) extends outside the outer tube (1) and is connected to an injection tube I (7), and a valve I (8) is provided on the injection tube I (7); a notch corresponding to the groove (4) is provided on the inner tube (2). Protrusions (9) are provided on the four peripheral edges of the notch on the inner tube (2), and the protrusions (9) are engaged with the groove (4).

2. The ECMO catheter according to claim 1 that can temporarily block blood flow, characterized in that: The blood flow blocking assembly further includes an injection channel II (10) axially provided in the wall of the outer tube (1). One end of the injection channel II (10) extends outside the outer tube (1) and is connected to an injection tube II (14), the other end of the injection channel II (10) extends into the outer tube (1), an injection hole (11) communicating with the injection channel II (10) is provided on the inner tube (2), a valve II (12) is provided on the injection tube II (14), and a micro check valve (13) is provided in the injection channel II (10).

3. The ECMO catheter capable of temporarily blocking blood flow according to claim 1 or 2, characterized in that: Two blood flow blocking assemblies are symmetrically provided on the outer tube (1).

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