A VA-ECMO femoral artery cannulation for lower limb blood perfusion

Abstract

This utility model relates to the field of medical device technology, specifically a VA-ECMO femoral artery cannula for lower limb blood perfusion. The technical solution includes: a cannula, the tip of which is guided into the femoral artery by a puncture guide; the tip of the cannula is connected to an output port, and the area with the output port on the tip of the cannula is divided into area A; a connector is connected to the rear end of the cannula; an aortic counterpulsation balloon is located in the middle of the outer surface of the cannula, with its tip close to area A; a bulging balloon is located on the cannula at the rear end of the aortic counterpulsation balloon, wherein the end of the bulging balloon facing the aortic counterpulsation balloon mates with the cannula wall at an obtuse angle, and the end away from the aortic counterpulsation balloon mates with the cannula wall at an acute angle; a balloon inlet is located on the side of the cannula away from the aortic counterpulsation balloon of the bulging balloon, for inflating the aortic counterpulsation balloon and the bulging balloon; and a side port is located on the cannula at the front end of the bulging balloon and the middle of the rear end of the aortic counterpulsation balloon.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a VA-ECMO femoral artery cannula for lower limb blood perfusion. Background Technology

[0002] Extracorporeal membrane oxygenation (ECMO) is a short-term life support technology widely used in the resuscitation of patients with acute cardiopulmonary failure. The venous-arterial (VA-ECMO) mode is primarily used for cardiogenic shock, cardiac arrest, and severe heart failure. VA-ECMO involves inserting arterial and venous cannulas to drain the patient's central venous blood to an extracorporeal oxygenator for gas exchange. A centrifugal pump then pumps the oxygenated blood back into the arterial system to maintain systemic circulatory perfusion. In clinical practice, femoral artery cannulation is the most commonly used arterial return route for VA-ECMO due to its ease of operation, minimal puncture trauma, and rapid establishment of extracorporeal circulation. However, traditional femoral artery cannulation techniques can lead to insufficient lower limb perfusion, causing ischemic complications such as distal limb ischemia and necrosis, and even affecting patient prognosis.

[0003] Because ECMO devices return blood to the femoral artery, causing high-flow, high-pressure reverse blood flow in the common femoral artery, it may inhibit the left ventricular ejection, further increasing the burden on the heart. In addition, femoral artery cannulation may obstruct blood flow to the distal lower limbs, increasing the risk of arterial thrombosis, limb ischemia, and nerve damage.

[0004] In view of the above, the existing publication CN112915294A proposes a solution. In actual clinical application, it has been found that due to changes in local hemodynamics, certain vascular bends are easily affected by turbulence, thereby increasing the risk of thrombosis. For example, the arc-shaped protrusion of the balloon causes large fluctuations in the distance between the balloon and the blood vessel during blood flow, which will aggravate local blood flow obstruction and further reduce blood flow susceptibility. In addition, after the balloon is inflated and blocked, it may lead to complete isolation of blood flow on both sides. Therefore, this application proposes a VA-ECMO femoral artery cannulation for lower limb blood perfusion to solve the above problems. Utility Model Content

[0005] In response to the above situation, this utility model provides a VA-ECMO femoral artery cannula for lower limb blood perfusion. This device uses an aortic counterpulsation balloon to continuously and repeatedly dilate blood vessels, reducing the insufficient lower limb perfusion caused by arterial vasoconstriction and generating pulse-like blood flow.

[0006] A VA-ECMO femoral artery cannula for lower limb blood perfusion includes:

[0007] The cannula is inserted into the femoral artery via a puncture guide; the front end of the cannula is connected to an output port, and the area with the output port at the front end of the cannula is divided into area A.

[0008] Connector, located at the rear end of the insertion tube;

[0009] The aortic counterpulsation balloon is positioned in the middle of the outer surface of the cannula, with its tip close to area A.

[0010] A bulging balloon is placed on the cannula at the rear end of the aortic counterpulsation balloon, wherein the end of the bulging balloon facing the aortic counterpulsation balloon mates with the cannula wall at an obtuse angle, and the end away from the aortic counterpulsation balloon mates with the cannula wall at an acute angle.

[0011] The balloon inlet is located on the cannula on the side of the bulging balloon away from the aortic counterpulsation balloon, and is used for inflating the aortic counterpulsation balloon and the bulging balloon.

[0012] The side port is located on the cannula at the front end of the bulging balloon and the middle of the rear end of the aortic counterpulsation balloon. The distance between the outlet end of the side port and the position of the bulging balloon and the opposite blood vessel wall tends to be gentle.

[0013] Preferably, there are multiple output holes, which are distributed in a ring in area A.

[0014] Preferably, the cannula surface in area A and the middle of the aortic counterpulsation balloon is provided with an annular guidewire.

[0015] Preferably, the balloon opening is provided with two balloon openings, which are symmetrically arranged on the intubation tube and are respectively connected to the aortic counterpulsation balloon and the bulging balloon.

[0016] Preferably, the diameter of the cannula's front end is smaller than its rear end diameter.

[0017] Preferably, the connector includes a plastic connector and a liquid injection port;

[0018] The plastic connector is connected to one end of the insertion tube;

[0019] The injection port is connected to the plastic connector.

[0020] The cannulation procedure for VA-ECMO femoral artery insertion in lower limb hemoperfusion is as follows:

[0021] First, guided by the puncture guide, the tip of the cannula is positioned towards the proximal femoral artery; the bulging balloon and aortic counterpulsation balloon are positioned inside the femoral artery, and the side holes are controlled to face the distal femoral artery. Infusion is then performed into the cannula through the connector.

[0022] Inflation is then performed through two balloon openings to the bulging balloon and the aortic counterpulsation balloon, respectively. After inflation, the bulging balloon can be used to position the cannula and prevent it from dislodging. The side of the inflated bulging balloon facing the aortic counterpulsation balloon forms an obtuse angle with the cannula wall, thereby narrowing the blood flow channel between the side port outlet and the bulging balloon and reducing turbulence. At the same time, the side of the bulging balloon away from the aortic counterpulsation balloon forms an acute angle with the cannula and engages with the vascular cannula at this acute angle. After engagement, the surface of the bulging balloon forms an obtuse angle contact area with the vessel wall, reducing turbulence on the side of the bulging balloon away from the aortic counterpulsation balloon and improving the stability of the cannula fixation.

[0023] Then, the aortic counterpulsation balloon is inflated and deflated synchronously with the patient's heart rate. During inflation, blood flow on both sides of the aortic counterpulsation balloon is blocked, while the constricted arteries dilate. During deflation, blood in the arteries flows again without being blocked by the aortic counterpulsation balloon, forming a pulse-like blood flow. The beneficial effects of the above technical solution are:

[0024] (1) By setting up an aortic counterpulsation balloon, the inflation is synchronized with the patient's heart rate. When inflating, blood flow is blocked and blood vessels are dilated. When deflated, blood flow is restored, forming a pulse-like blood flow.

[0025] (2) By setting the obtuse and acute angles of the bulging airbag, the cannula is prevented from accidentally moving or falling out in the blood vessel, thus improving the stability of the insertion. Its special angle after inflation (forming an obtuse and acute angle with the cannula wall) optimizes the fit with the blood vessel wall, reduces turbulence and further enhances the fixation effect. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0027] Figure 2 This is a schematic diagram of the single-lumen cannulation structure of this utility model;

[0028] Figure 3 This is a schematic diagram of the dual-lumen cannulation of this utility model;

[0029] Figure 4 This is a schematic diagram of the inflatable bladder structure of this utility model.

[0030] In the diagram: 1. Intubation cannula; 101. Area A; 2. Puncture guide; 3. Output port; 4. Connector; 41. Material connector; 42. Injection port; 5. Aortic counterpulsation balloon; 6. Bulb balloon; 7. Balloon port; 8. Side hole; 9. Circular guidewire; 10. Inflatable balloon. Detailed Implementation

[0031] The foregoing and other technical contents, features and effects of this utility model are described in conjunction with the appendix below. Figures 1 to 4As will be clearly shown in the detailed description of the embodiments, all structural contents mentioned in the following embodiments are based on the accompanying drawings.

[0032] For reference Figure 1 This application proposes a femoral artery cannulation method for lower limb blood perfusion VA-ECMO, as detailed below:

[0033] For reference Figure 1 This application consists of a cannula 1, a puncture guide 2 for guiding the cannula 1 into the femoral artery, an output port 3 located at the front end of the cannula 1, a connector 4 connected to the rear end of the cannula 1, a bulging balloon 6 and an aortic counterpulsation balloon 5 located on the cannula 1, a balloon inlet 7 for inflation, and a side hole 8 located on the cannula 1. Through the cooperation of these structures, VA-ECMO femoral artery cannulation for lower limb blood perfusion is achieved, which reduces the formation of thrombi during operation and forms pulse-like blood flow.

[0034] For reference Figure 1 The diameter of the front end of the cannula 1 is smaller than that of the rear end, and the diameter of the rear end gradually increases to form a large connection port, which makes it easier to connect with the connector 4. Blood can be input into the cannula 1 through the connector 4. The front end of the cannula 1 is provided with an output port 3, and the cannula 1 at the front end of the balloon 6 and the middle of the rear end of the aortic counterpulsation balloon 5 is provided with a side port 8. When blood enters the output port 3, blood is injected outward through the output port 3 and the side port 8.

[0035] It should be noted that the diameter from the output port 3 to the bulging balloon 6 on the cannula 1 is the same, which is the front diameter; the diameter gradually increases from the end of the bulging balloon 6 away from the aortic counterpulsation balloon 5, which is the rear diameter. The rear diameter can be adjusted until it is suitable for connection with the connector 4. The front diameter can be adapted to the femoral artery insertion, and the rear diameter is not specifically limited. The diameter can be adjusted based on different models of connector 4.

[0036] It should be noted that the area where the output hole 3 is set in the insertion tube 1 is divided into area A 101, and multiple output holes 3 are arranged in a ring within area A 101.

[0037] Furthermore, the connector 4 includes a plastic connector 41 and an injection port 42. The plastic connector 41 is connected to one end of the insertion tube 1, and the injection port 42 is connected to the plastic connector 41. The liquid enters the plastic connector 41 and is guided into the insertion tube 1 through the connection of the injection port 42 to the outside.

[0038] For reference Figures 1-2In one embodiment, the cannula 1 has only one inner lumen, and the side hole 8 and the output hole 3 are both connected to the inner lumen; when blood enters the inner lumen of the cannula 1 through the connector 4, the blood can be diverted from the side hole 8 and the output hole 3 into the femoral artery.

[0039] For reference Figure 1 and Figure 3 In another embodiment, the cannula 1 has two lumens, which are respectively connected to the side hole 8 and the output hole 3. The connector 4 connected to it needs to be provided with two injection ports 42. The two injection ports 42 are respectively connected to the two lumens. When blood enters the cannula 1 through the connector 4, it is already diverted and enters the two lumens respectively. Then, it enters the femoral artery through the holes (side hole 8 and output hole 3) that are connected to the two lumens.

[0040] Given the above two embodiments, the first embodiment is the best, as it has fewer connecting components and is more convenient to operate; while in the second embodiment, the output of the two holes can be controlled separately, thus allowing for different implementation methods to be selected in different scenarios.

[0041] For reference Figures 1-3 The aortic counterpulsation balloon 5 is located at the middle of the outer surface of the cannula 1, with its front end close to area A 101. An annular guidewire 9 is provided between the front end of the aortic counterpulsation balloon 5 and the middle of area A 101. The annular guidewire 9 can increase the toughness of the puncture tube and facilitate puncture. It should be noted that the aortic counterpulsation balloon 5 is connected to an external control console. The control console delivers and recovers gas through a pneumatic system to realize inflation / deflation. This is the operating principle of existing relatively mature mechanical circulatory auxiliary devices, which will not be elaborated further in this application.

[0042] With the aortic counterpulsation balloon 5, the inflation and deflation are synchronized with the patient's heart rate. The balloon is inflated when the patient's pulse is beating and deflated when the patient's pulse stops, thereby repeatedly dilating the blood vessels and forming a pulse-like blood flow. This helps to restore vascular elasticity, improve blood supply, promote collateral circulation, prevent restenosis, and reduce thrombus formation.

[0043] For reference Figures 1-3 The bulging balloon 6 is used to position the cannula 1 and prevent it from slipping out of the femoral artery during operation. The bulging balloon 6 is specifically set on the cannula 1 at the rear end of the aortic counterpulsation balloon 5. A side hole 8 is set in the middle of the bulging balloon 6 and the aortic counterpulsation balloon 5. When blood is injected into the blood vessel through the side hole 8, the pressure at the outlet end of the side hole 8 is relatively high, which can easily cause turbulence and thus easily lead to thrombus accumulation. To further improve this problem, the shape of the bulging balloon 6 is further improved. The end of the bulging balloon 6 facing the aortic counterpulsation balloon 5 fits with the wall of the cannula 1 at an obtuse angle, and the end away from the aortic counterpulsation balloon 5 fits with the wall of the cannula 1 at an acute angle.

[0044] Its obtuse-angle design makes the distance between the outlet position of the injected blood and the position of the bulging air sac 6 and the femoral artery facing the front side more gradual when the blood flows out from the side hole 8, so the blood flow velocity is relatively stable. By optimizing the design of the bulging air sac (6), the existing large air sac is avoided, which leads to a reduction in the distance between the air sac and the opposite blood vessel wall. This can effectively reduce the occurrence of irregular flow paths and achieve the effect of reducing turbulence.

[0045] The acute angle at the other end creates an obtuse angle contact area between the surface of the bulging airbag 6 and the blood vessel wall, which helps maintain a gentle flow velocity gradient during blood flow in the blood vessel, effectively reducing drastic changes in flow velocity and lowering the risk of turbulence. Secondly, the acute angle can better engage with the femoral artery, making the connection and locking effect more stable and less prone to outward slippage.

[0046] For reference Figure 1 The bulging balloon 6 and the aortic counterpulsation balloon 5 are inflated and deflated through the balloon openings 7. There are two balloon openings 7, which are independently connected to the bulging balloon 6 and the aortic counterpulsation balloon 5, respectively, to ensure independent inflation and deflation operations and improve control accuracy. To improve the convenience of operation, the positions of the two balloon openings 7 have been optimized. The balloon opening 7 connected to the bulging balloon 6 is located on the side away from the aortic counterpulsation balloon 5 and is located on the cannula 1, arranged horizontally with the bulging balloon 6, which is convenient for operation and identification. The balloon opening 7 connected to the aortic counterpulsation balloon 5 is located directly in front of the balloon opening 7 connected to the bulging balloon 6, so that the two balloon openings 7 are symmetrically distributed.

[0047] In practical applications, by observing the position of the balloon port 7 connected to the aortic counterpulsation balloon 5, the position of the balloon port 7 connected to the symmetrical bulging balloon 6 can be inferred, thereby quickly locating the bulging balloon 6, which facilitates the adjustment of the cannula 1 and the operation of the equipment.

[0048] For reference Figure 4 In the prior art, most inflatable balloons 10 adopt an arc-shaped protrusion design. In order to ensure its locking function, its diameter is usually greater than or equal to the diameter of the blood vessel lumen, thereby enhancing the fixation effect and reducing the risk of the cannula 1 slipping out. However, under this design, four points are formed between the side hole 8 and the inflatable balloon 10: P1, P2, P3 and P4. The four points represent the change in the distance between the side hole 8 and the inflatable balloon 10 and the inner wall of the blood vessel, corresponding to the change in the distance between the side hole 8 outlet position and the acute angle of the bulging balloon 6 and the blood vessel wall in this application.

[0049] For reference Figure 4There are significant changes in the distance between P1, P2, and P3, leading to uneven blood flow when injected into the femoral artery, thus increasing the probability of turbulence formation. In contrast, the obtuse angle setting of this application makes the distance between the side hole 8 outlet and the acute angle of the bulging balloon 6 and the vessel wall more gradual, avoiding drastic fluctuations in blood velocity at this location, thereby reducing turbulence formation. Secondly, when flowing to P4, the arrangement of the inflatable balloon 10 and the cannula 1 after insertion into the blood vessel forms a significant angle with the vessel wall, easily inducing turbulence when blood flows through this area (P4), affecting the overall blood flow stability. In this application, the side of the bulging balloon 6 that forms an obtuse angle with the cannula 1 is straight, with almost no significant fluctuations or irregular undulations. After the bulging balloon 6 is placed into the blood vessel, this side forms an obtuse angle contact area with the vessel wall of the bulging balloon 6 away from the aortic counterpulsation balloon 5. This setting helps this area (relative to...) Figure 4 Maintaining a gentle flow gradient at the P1-P3 positions effectively reduces the bulging of the distal end of the airbag 6 (relative to the bulge). Figure 4 Local fluid disturbance at the P4 position reduces turbulence formation and thus improves blood flow.

[0050] In view of the above, the cannulation method for VA-ECMO femoral artery insertion for lower limb blood perfusion is as follows:

[0051] First, using the guiding function of the puncture guide 2, the tip of the cannula 1 is precisely oriented towards the proximal position of the femoral artery to ensure that the cannula 1 enters the arterial vascular system smoothly. During this process, it is necessary to ensure that the angle of the puncture guide 2 is appropriate to reduce damage to the vascular wall and ensure that the cannula 1 can be smoothly advanced to the predetermined position.

[0052] After the cannula 1 is successfully inserted into the blood vessel, it is necessary to ensure that the bulging balloon 6 and the aortic counterpulsation balloon 5 are both inside the femoral artery, and adjust the orientation of the side hole 8 so that it points to the distal end of the femoral artery; at this time, perfusion is performed into the cannula 1 through the connector 4 to ensure the stability of the fluid environment in the lumen, and at the same time check the patency of the cannula 1.

[0053] Next, the bulging balloon 6 and the aortic counterpulsation balloon 5 are inflated through the two balloon ports 7 to reach their working state. After inflation, the bulging balloon 6 can effectively position the intubation cannula 1 and prevent it from falling off due to blood flow impact or external operation. The side of the inflated bulging balloon 6 facing the aortic counterpulsation balloon 5 forms an obtuse angle with the wall of the intubation cannula 1. This structural design helps to reduce the difference in blood flow channel width between the side hole 8 outlet and the bulging balloon 6, thereby reducing the formation of turbulence and improving the stability of blood flow.

[0054] Furthermore, the side of the bulging balloon 6 furthest from the aortic counterpulsation balloon 5 forms an acute angle with the wall of the cannula 1. This acute angle structure forms an effective locking point between the cannula 1 and the arterial wall, allowing the cannula 1 to be more securely fixed in the blood vessel. At the same time, due to the combination of the obtuse and acute angles of the bulging balloon 6 and its connection state with the blood vessel wall under its design, the blood flow process in the blood vessel maintains a gentle flow velocity gradient, thereby effectively reducing drastic changes in flow velocity and lowering the risk of turbulence.

[0055] After the balloon 6 is inflated and the cannula 1 is fixed in place, the aortic counterpulsation balloon 5 is inflated and deflated synchronously with the patient's heart rate. During inflation, the aortic counterpulsation balloon 5 blocks the blood flow on both sides, restricting the blood flow in the aortic lumen and interfering with the expansion and contraction of the arteries, thereby achieving the counterpulsation effect. When the aortic counterpulsation balloon 5 deflates, the blood in the artery can resume flow without being blocked by the aortic counterpulsation balloon 5, forming a pulse-like blood flow.

[0056] The above description is only for illustrating the present utility model. It should be understood that the present utility model is not limited to the above embodiments, and various modifications that conform to the concept of the present utility model are within the protection scope of the present utility model.

Claims

1. A VA-ECMO femoral arterial cannula for lower limb blood perfusion, characterized in that, include: Insert a cannula (1), and guide the tip of the cannula into the femoral artery through a puncture guide (2); The front end of the insertion tube (1) is connected to an output hole (3), and the area with the output hole (3) at the front end of the insertion tube (1) is divided into area A (101); Connector (4), which is located at the rear end of the insertion tube (1); The aortic counterpulsation balloon (5) is placed in the middle of the outer surface of the cannula (1), with its front end close to area A (101); A bulging balloon (6) is placed on the cannula (1) at the rear end of the aortic counterpulsation balloon (5). The end of the bulging balloon (6) facing the aortic counterpulsation balloon (5) is fitted with the wall of the cannula (1) at an obtuse angle, and the end away from the aortic counterpulsation balloon (5) is fitted with the wall of the cannula (1) at an acute angle. The balloon opening (7) is located on the cannula (1) on the side of the bulging balloon (6) away from the aortic counterpulsation balloon (5) and is used for inflating the aortic counterpulsation balloon (5) and the bulging balloon (6). The side hole (8) is located on the cannula (1) at the front end of the bulging balloon (6) and the middle of the rear end of the aortic counterpulsation balloon (5). The distance between the outlet end of the side hole (8) and the position of the bulging balloon (6) and the opposite blood vessel wall tends to be gentle.

2. VA-ECMO femoral arterial cannula for lower limb blood perfusion according to claim 1, characterized in that, There are multiple output holes (3), which are distributed in a ring in area A (101).

3. VA-ECMO femoral arterial cannula for lower limb blood perfusion according to claim 1, characterized in that, The cannula (1) in the middle of the A region (101) and the aortic counterpulsation balloon (5) is provided with a ring guidewire (9).

4. VA-ECMO femoral arterial cannula for lower limb blood perfusion according to claim 1, characterized in that, The balloon port (7) is provided in two parts, and the two balloon ports (7) are symmetrically arranged on the cannula (1) and are respectively connected to the aortic counterpulsation balloon (5) and the bulging balloon (6).

5. The lower limb blood perfusion VA-ECMO femoral arterial cannula according to claim 1, characterized in that, The diameter of the portion of the cannula (1) inserted under the skin at the front end is smaller than the diameter at the rear end.

6. The lower limb blood perfusion VA-ECMO femoral arterial cannula according to claim 1, characterized in that, The connector (4) includes a plastic connector (41) and an injection port (42); The plastic connector (41) is connected to one end of the insertion tube (1); The injection port (42) is connected to the plastic connector (41).

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