Sleeve for smoothly feeding blood

Abstract

The invention provides a cannula capable of effectively and smoothly conveying blood from the ascending aorta while reducing the diameter of the cannula. And the front end part of the cannula is retained in the ascending aorta and is used for smoothly conveying blood supplied by the in-vitro artificial membrane lung from the ascending aorta. The cannula comprises a forward blood backflow part (2) and a blood delivery tube (4), wherein the forward blood backflow part (2) is arranged at the front end of the blood delivery tube (4). A guide wire tube (5) which longitudinally extends from a base end part to a front end part is arranged at a near-center position of the axial length in the smooth blood feeding sleeve (1). The blood delivery tube (4) is a catheter arranged on the base end side and used for being connected with the in-vitro artificial membrane lung. The forward blood return unit (2) reverses blood from a reverse direction to a forward direction and guides the blood to the base end side, and is provided with a first blood return tube (6) provided on the base end side and a second blood return tube (7) provided on the tip side. The second blood return tube (7) has side holes (7a, 7b), and a part of an approximately hemispherical bag body (8) is adhered to the inner portion of the tip of the second blood return tube (7).

Description

Technical Field

[0001] This invention relates to a cannula for an extracorporeal circulatory system. Background Technology

[0002] In cases of myocardial infarction or other conditions that cause a sudden decrease in the heart's pumping function, the left ventricle may become excessively enlarged, preventing it from contracting. In such situations, the left ventricle cannot pump enough blood, depriving vital organs throughout the body, including the brain, of adequate oxygenated blood. In these cases, intervention with a cardiopulmonary bypass device is necessary.

[0003] Currently used percutaneous extracorporeal circulation support devices include intracardiac pump catheters for circulatory support (IMPELLA (registered trademark)) and percutaneous cardiopulmonary support systems (ECMO (PCPS)). While IMPELLA can reduce the workload on the heart, it has drawbacks such as inability to provide oxygen and strict equipment standards.

[0004] In contrast, ECMO is widely used because it can provide oxygenation and is not limited by equipment, but its main problem is that retrograde blood delivery increases the workload on the heart. In addition, because a large-diameter cannula must be left in place, vascular complications associated with the cannula are also a significant issue.

[0005] First, regarding the first question, namely that retrograde blood delivery increases the workload on the heart, ECMO is a device that supplies oxidized blood to vital organs, such as the brain. However, because the blood is delivered at a high flow rate in the opposite direction to the blood pumped out by the heart, it puts a strain on the heart, which may prolong the recovery time of heart function.

[0006] Secondly, regarding the second question, namely vascular complications associated with large-diameter cannulas, the incidence of lower limb ischemia after ECMO delivery vessels are inserted via the femoral artery is estimated to be approximately 10% to 70%. If lower limb ischemia occurs, it may lead to compartment syndrome or lower limb necrosis, and the prognosis for patients with lower limb ischemia will significantly worsen.

[0007] A meta-analysis of 1,763 adult patients focusing on ECMO outcomes and complications showed that, despite generally being at high risk of death, nearly 50% of patients receiving ECMO were still alive at discharge, while a significant number (45%) died from complications such as bleeding (33%) or sepsis (22%) caused by long-term ECMO placement (see, for example, Non-Patent Literature 1).

[0008] In recent years, a technology called "ECPELLA" has been widely used. This technology combines IMPELLA with ECMO, which can deliver oxygenated blood to the brain while reducing the burden on the heart. However, because the use of IMPELLA remains unchanged, there are strict facility standards to consider.

[0009] Therefore, as a blood delivery cannula used in extracorporeal blood circulation using an artificial heart and lung, a cannula capable of antegrade blood delivery is known (see Patent Document 1). This cannula consists of an outer tube and an inner tube, and blood is released antegradely into the aorta through a drainage hole in the outer tube, which is closed at the front end, forming an annular reflux channel between the outer and inner tubes.

[0010] However, in the cannula of Patent Document 1, although inwardly protruding portions are provided at the edges of each discharge hole as a mechanism to guide the blood discharge direction in the forward direction, these inwardly protruding portions can only guide the blood inside the outer tube, and cannot guide the blood discharged from the outer tube. Therefore, there is a problem of insufficient forward-direction guidance effect. In addition, the cannula of Patent Document 1 is arranged in such a way that the outer tube covers the inner tube, so there is a structural problem of difficulty in reducing the diameter of the cannula.

[0011] [Patent Documents]

[0012] [Patent Document 1] Japanese Patent Application Publication No. 2015-23970

[0013] [Non-patent literature]

[0014] [Non-patent text 1] Alberto Zangrillo et al., "A meta-analysis of complications and mortality of extracorporeal membrane oxygenation", Crit CareResusc. 2013Sep; 15(3):172-8. Summary of the Invention

[0015] The technical problem that the invention aims to solve

[0016] In view of the above, the object of the present invention is to provide a cannula that, while achieving a smaller diameter, can effectively deliver blood antegradely from the ascending aorta.

[0017] To address the aforementioned problems, the present invention provides an antegrade blood delivery cannula, which is a cannula with its front end inserted into the ascending aorta and delivers blood supplied by an extracorporeal membrane oxygenation (ECMO) via the ascending aorta. The cannula comprises: a delivery vessel disposed at the base of the cannula and connectable to the ECMO; and an antegrade blood return section disposed at the front end of the cannula. The antegrade blood return section includes: an antegrade blood return mechanism that reverses the blood flow from retrograde to antegrade and guides the blood towards the base; and a blood delivery pressure regulating mechanism that adjusts the blood delivery pressure.

[0018] By incorporating an antegrade blood return section, collisions between blood supplied from the extracorporeal membrane oxygenation (ECMO) and blood from the heart can be prevented, effectively reducing the workload on the heart. Furthermore, the blood delivery pressure regulation mechanism reduces irritation to the vascular lining, preventing the spread of atherosclerotic plaques.

[0019] In addition, extracorporeal membrane oxygenation (ECMO) here refers to a device that oxygenates extracted blood outside the body and then returns it to the body, such as a percutaneous cardiopulmonary bypass device (ECMO).

[0020] In the forward-flow blood delivery cannula of the present invention, a forward-flow blood return section is formed with a blood return tube. The front end of the blood return tube is closed and has at least two side holes on the front end side. A portion of a roughly hemispherical bag is adhered to the inner side of the front end of the blood return tube, and the open end of the bag is positioned around the entire periphery of the blood return tube, including the side holes. Furthermore, in the forward-flow blood return mechanism, the side holes open when the blood delivery pressure exceeds a predetermined threshold, and the bag is used to alleviate the blood delivery pressure in the blood delivery pressure regulating mechanism.

[0021] By employing a structure with an openable and closable bag opening, a smaller cannula diameter can be achieved. Regarding the side holes on the blood return tube, to prevent sudden movement of the blood return tube within the patient's body, when two side holes are provided, it is preferable to place them opposite each other on the tube body. When three or more side holes are provided, it is preferable to arrange them at approximately equal intervals around the tube body. The pressure value exceeding the specified threshold depends on the material of the bag body and the size of the side holes. Regarding the material of the bag body, for example, if it is desired to enhance the mitigation effect of blood pressure in the blood delivery pressure regulating mechanism, a more elastic bag material can be selected. Furthermore, "front-end closure" refers to a state where the blood flow path is closed; when setting the guidewire cannula as described later, the cannula tip is open.

[0022] In the forward-flowing blood delivery cannula of the present invention, specifically, the blood return tube is formed by bonding or screwing together a first blood return tube disposed on the base end side and a second blood return tube disposed on the front end side. The front end of the first blood return tube has an extension portion with a diameter smaller than that of the base end side. When the pressure caused by blood delivery does not exceed a predetermined threshold, the outer surface of the extension portion abuts against and blocks a portion of the opening end of the bag body; when the pressure caused by blood delivery exceeds the predetermined threshold, the abutment between the outer surface of the extension portion and the portion of the opening end of the bag body is released. In the forward-flowing blood return mechanism, when the abutment is released, the flow path formed between the extension portion and a portion of the opening end of the bag body can improve the forward flow capability of blood.

[0023] By providing an extension section, the flow path formed between the extension section and a portion of the opening end of the bag body is approximately parallel to the flow path before reversal, thus improving the forward flow of blood after reversal. The first and second blood return tubes can be fixed not only by adhesive or screwing, but also by a combination of adhesive and screwing to enhance the fixation strength.

[0024] In the antegrade blood delivery cannula of the present invention, the antegrade blood return section is formed by extending the delivery vessel. The antegrade blood return mechanism can also be formed by bending the front end of the extended delivery vessel into a U-shape. The blood delivery pressure regulating mechanism has at least two side holes formed in the middle portion of the extended delivery vessel. By bending the front end of the delivery vessel into a U-shape, antegrade blood delivery can be achieved with a simpler structure.

[0025] Additionally, by providing side holes in the middle section, a simplified structure can be used to adjust the blood delivery pressure. The term "U-shape" is not a strict definition, but rather broadly encompasses a curved shape that reverses the direction of blood flow through the delivery vessel.

[0026] In the antegrade blood delivery cannula of the present invention, a guidewire is preferably provided at its proximal center, extending longitudinally from the base end to the front end. By providing a guidewire, not only can a smaller diameter be achieved, but the guidewire can also be inserted into and pass through the interior of the antegrade blood delivery cannula, thereby improving operational convenience. In addition, the holes for the guidewire can be provided along the outer wall of the antegrade blood delivery cannula.

[0027] Invention Effects

[0028] The antegrade blood delivery cannula of the present invention has the effect of achieving a smaller diameter and reducing the cardiac load on the patient. Therefore, it can reduce the incidence of vascular complications caused by the insertion of large-diameter cannulas.

[0029] In addition, the antegrade blood delivery cannula according to the present invention can deliver oxygenated blood antegradely from the ascending aorta, effectively delivering blood to the whole body, including the brain. Attached Figure Description

[0030] Figure 1 This is an external view of the first embodiment of the antegrade blood delivery cannula;

[0031] Figure 2 This is a cross-sectional schematic diagram of the antegrade blood return section in the first embodiment;

[0032] Figure 3 This is a schematic diagram of the appearance of the antegrade blood return section in the first embodiment;

[0033] Figure 4 This is an example of the configuration of the second blood return tube;

[0034] Figure 5 This is a schematic diagram illustrating the use of the antegrade blood delivery cannula of the present invention;

[0035] Figure 6 This is an external view of the antegrade blood delivery cannula in the second embodiment;

[0036] Figure 7 This is an explanatory diagram of the side holes in the middle section;

[0037] Figure 8 This is an external view of the third embodiment of the antegrade blood delivery cannula;

[0038] Figure 9 This is a schematic diagram of the use of existing blood delivery cannulas;

[0039] Figure 10 This is a schematic diagram of a pulsating cycle simulator;

[0040] Figure 11 This is the performance evaluation test result of the first implementation form of the antegrade blood delivery cannula. Detailed Implementation

[0041] First, let's explain the existing impressions of using blood delivery cannulas.

[0042] Figure 9 The impression of existing blood delivery cannulas is shown. In existing retrograde blood delivery, blood 9b, which is fully oxidized and transported in an extracorporeal membrane oxygenator (not shown), is delivered to the descending aorta 91, aortic arch 92, right subclavian artery 94, right common carotid artery 95, left common carotid artery 96, left subclavian artery 97, and supplies blood 9b to the brain 82.

[0043] However, under the existing retrograde blood delivery system, blood 9b collides with blood 9c delivered from the heart 81 at the ascending aorta 93, thus contributing to cardiac load. Furthermore, due to the collision between the blood flow from the extracorporeal membrane oxygenation (ECMO) and the blood flow from the heart 81, there is a problem that the oxidized blood 9b from the ECMO cannot be adequately supplied to the brain 82.

[0044] In response to this, the antegrade blood delivery cannula of the present invention, as described below, solves the problem of retrograde blood delivery. Figure 5 This diagram illustrates the use of the antegrade blood delivery cannula of the present invention. For ease of explanation, here... Figure 5 The sleeve itself is not shown.

[0045] like Figure 5 As shown, in the antegrade blood delivery cannula of the present invention, the tip of the cannula is inserted into the ascending aorta 93. Blood 9a is delivered through the cannula to the ascending aorta 93 and then discharged antegradely. Thus, the discharged blood 9b does not collide with the blood 9c from the heart 81, but flows antegradely through the aortic arch 92, descending aorta 91, right subclavian artery 94, right common carotid artery 95, left common carotid artery 96, and left subclavian artery 97, ultimately reaching the brain 82. This reduces the workload on the heart and allows oxygenated blood from the extracorporeal membrane oxygenation (ECMO) to be smoothly supplied to the whole body, including the brain 82.

[0046] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that the scope of the present invention is not limited to the embodiments and the illustrated implementations, and various modifications and alterations are possible.

[0047]

Example 1

[0048] Figure 1 An external view of the antegrade blood delivery cannula according to a first embodiment is shown. The antegrade blood delivery cannula 1 has its distal end placed within the ascending aorta and delivers blood supplied from an extracorporeal membrane oxygenation (ECMO) vessel antegradely through the ascending aorta. The antegrade blood delivery cannula 1 consists of an antegrade blood return section 2 and a delivery vessel 4, wherein the antegrade blood return section 2 is located at the distal end of the delivery vessel 4. A guidewire hole extending longitudinally from the base to the distal end is provided at the proximal center of the antegrade blood delivery cannula 1, and a guidewire 5 is disposed in this hole.

[0049] Delivery tube 4 is a catheter located at the base end for connecting to the extracorporeal membrane oxygenator (ECMO), with an outer diameter of 9 Fr (French catheter size). This represents a reduction in diameter compared to delivery tubes typically used in ECMO (approximately 14–18 Fr). Here, Fr is a unit representing the outer diameter of catheters and other tubing types; a 1 Fr diameter circular catheter is 1 / 3 millimeter in diameter.

[0050] The antegrade blood return section 2 reverses the blood flow from retrograde to antegrade and guides it towards the base side. It consists of a first blood return tube 6 located at the base side and a second blood return tube 7 located at the tip side. The second blood return tube 7 has a closed tip and two side holes (7a, 7b). Additionally, a portion of a roughly hemispherical bag 8 is adhered to the inner side of the tip of the second blood return tube 7. Here, "tip closure" refers to the closure of the blood flow path; since the guidewire tube 5 itself does not constitute a blood flow path, its tip is not closed.

[0051] Figure 2 This is a cross-sectional schematic diagram of a antegrade blood delivery cannula, where (1) represents the state of not delivering blood and (2) represents the state of delivering blood. Figure 3 This is a schematic diagram of the appearance of the antegrade blood delivery cannula, where (1) and (2) are side views, and (3) and (4) are views viewed from the front end. Figure 3 In the diagram, (1) and (3) represent states where blood is not being transported, while (2) and (4) represent states where blood is being transported.

[0052] like Figure 2 As shown in (1), the first blood return tube 6 and the second blood return tube 7 are fitted, bonded, and fixed together. The outer diameter of the first blood return tube 6 is 9Fr. Additionally, a portion of the approximately hemispherical bag body 8 is adhered to the inner side of the pointed portion 70 at the front end of the second blood return tube 7. The bonding can be done at one point or in multiple locations. Figure 3 As shown in (3), the open end of the bag body 8 is set around the entire periphery of the blood return tube including the side holes (7a, 7b).

[0053] like Figure 2 As shown in (1), because the front end of the first blood return tube 6 has an extension 6a with a diameter smaller than that of the base end, when the pressure caused by blood delivery does not exceed a predetermined threshold, the outer peripheral surface of the extension 6a will abut against and block a portion of the abutment area of ​​the opening end of the bag body 8. Conversely, when the pressure caused by blood delivery exceeds the predetermined threshold, such as Figure 2 (2) As shown, the contact between the outer peripheral surface of the extension 6a and a portion of the opening end of the bag body 8 is released.

[0054] In the forward-flowing blood return mechanism, when the blocking state is released, the forward-flowing capability is further enhanced by the flow path formed between the extension 6a and a portion of the opening end of the bag body 8. Specifically, since the flow path formed between the extension 6a and a portion of the opening end of the bag body 8 is approximately parallel to the flow path before reversal, it is possible to prevent... Figure 2 (2) The reversed blood 9 spreads in the vertical direction, which improves the forward flow of the reversed blood.

[0055] In addition, since the bag body 8 is made of highly flexible and elastic materials such as silicone, polyurethane, polyvinyl chloride, polyester, and natural rubber, the degree of opening and closing of the opening end can be automatically adjusted according to the flow rate and velocity of blood 9.

[0056] As described above, in the antegrade blood delivery cannula 1 of the first embodiment, the side holes (7a, 7b) open when the blood delivery pressure exceeds a predetermined threshold, and the blood delivery pressure regulating mechanism alleviates the blood delivery pressure through the bag body 8. Figure 3 As shown in (2) or (4), the bag body 8 is only opened when blood is delivered to play the role of the antegrade blood return mechanism, so that antegrade blood delivery and narrowing can be achieved at the same time.

[0057] Figure 4 This illustrates a structural example of the second blood return tube. In the first embodiment of the antegrade blood delivery cannula 1, two side holes (7a, 7b) are provided on the second blood return tube 7, but it can also be arranged as follows... Figure 4 (1) As shown in the second blood return tube 71, it is provided with three side holes (7c~7e), and can also be like Figure 4 (2) As shown in the second blood return tube 72, it is provided with four side holes (7f~7i).

[0058]

Example 2

[0059] Figure 6 This is an external view showing the antegrade blood delivery cannula of the second embodiment. The antegrade blood delivery cannula 10 of the second embodiment consists of delivery tubes 3 and 4 and an antegrade blood return section 20.

[0060] Figure 7 An explanatory diagram showing the side holes in the middle section. (See diagram for example.) Figure 7 As shown, two side holes (3a, 3b) are formed in the middle part of the blood supply vessel 3, which can reduce the blood pressure of the blood supply vessel.

[0061] The blood supply vessel 3 is made of a non-mesh material. In contrast, the blood supply vessel 4 is made of a mesh material to enhance its rigidity. Furthermore, the antegrade blood return section 20 is made of the same material as the blood supply vessel 4 and has a mesh structure to maintain its curved shape.

[0062] Therefore, in the second embodiment of the antegrade blood delivery cannula 10, the antegrade blood return mechanism refers to the antegrade blood return section 20 formed by bending the front end of the extended delivery tube 4 into a U-shape, and the blood delivery pressure adjustment mechanism refers to the two side holes (3a, 3b) formed in the middle part of the extended delivery tube 3.

[0063]

Example 3

[0064] Figure 8This is an external view showing the antegrade blood delivery cannula of the third embodiment. In the antegrade blood delivery cannula 11 of the third embodiment, similar to the antegrade blood delivery cannula 10 of the second embodiment, a delivery tube 3 is provided with two side holes (3a, 3b). Other structures are the same as the antegrade blood delivery cannula 1 of the first embodiment. By providing the delivery tube 3, the adjustment of the delivery pressure becomes easier.

[0065] As described above, the antegrade blood return mechanism in the antegrade blood delivery cannula 11 in the third embodiment is a mechanism that opens the side holes (7a, 7b) when the blood delivery pressure exceeds a specified threshold, and the blood delivery pressure regulating mechanism is a mechanism that mitigates the blood delivery pressure through the bag body 8 and the two side holes (3a, 3b) formed in the middle part of the blood delivery tube 3.

[0066]

Example 4

[0067] Using a pulsatile circulation simulator (a non-clinical trial system established by the Iwasaki Laboratory at Waseda University capable of evaluating Class IV devices (highly regulated medical devices)), a hemodynamic simulation environment for cardiogenic shock was constructed. Furthermore, using the antegrade blood delivery cannula from Example 1 above with an existing centrifugal pump, the effects of antegrade blood delivery on aortic blood flow and cardiac load reduction were quantitatively evaluated by comparing its performance with existing retrograde blood delivery methods.

[0068] Figure 10 This diagram illustrates the pulsatile circulation simulator used in the performance evaluation test. The pulsatile circulation simulator 21 consists of a pneumatic actuator 22, a left ventricular model 23, a pressure loading chamber 24, a mitral valve model 25, pulmonary vascular resistance 26, aortic valve model 27, a catheter insertion port 28, an ultrasonic flowmeter 29, an aortic model 30, a venous reservoir 31, and peripheral resistance 32. The aortic flow rate Q1 [L / min] is obtained via the ultrasonic flowmeter 29, while the aortic pressure P1 and left ventricular pressure P2 [mmHg] are obtained via pressure transducers. Furthermore, the pulmonary vascular resistance 26 and peripheral resistance 32 are adjusted by opening and closing valves to control blood flow resistance.

[0069] Insert the cannula through the catheter insertion port 28 and place the tip of the cannula near the aortic valve model 27 of the aortic model 30 for testing.

[0070] The performance evaluation test of the antegrade blood delivery cannula used the antegrade blood delivery cannula from Example 1 (Examples A and Example B with different cannula diameters) and the retrograde blood delivery cannula (comparative example). Furthermore, the outer diameter of the antegrade blood delivery cannula 1 in Example 1 is 9 Fr, while the outer diameters of the antegrade blood delivery cannulas used in the evaluation objects are 13 Fr (Example A) and 11 Fr (Example B), respectively. The remaining structures are the same as in Example 1.

[0071] Additionally, as a comparative example, a retrograde blood delivery cannula (PCKC-A2) manufactured by Izumi Kogyo Medical Industry Co., Ltd. was used. The outer diameter of the retrograde blood delivery cannula in the comparative example was 18Fr. Furthermore, a blood collection cannula (PCKC-V2) manufactured by Izumi Kogyo Medical Industry Co., Ltd., with an outer diameter of 18Fr, was used for blood delivery, and a centrifugal pump and control unit (CAPIOX SP-101, TERUMO) were used.

[0072] The driving conditions were measured before pump actuation (at 0 rpm) and at 3000 rpm. As test conditions for the cardiac circulation simulator, a heart rate of 70 beats / min, aortic flow rate of 2.8 L / min, and aortic pressure of 70 / 30 (50) mmHg were set to construct hemodynamic parameters under cardiogenic shock. Simultaneously, to simulate human blood viscosity, a saline (concentration adjusted to 0.9%) aqueous glycerol solution (20°C, 33%) was used as the working fluid. Furthermore, aortic blood flow rate [L / min] was obtained using an ultrasonic flow meter, while aortic pressure and left ventricular pressure [mmHg] were measured using a pressure sensor.

[0073] Reference Figure 11 The results of the performance evaluation test of the antegrade blood delivery cannula are explained.

[0074] Comparing the results before pump drive (0 rpm) with the results at 3000 rpm, it can be seen that in the comparative example, the left ventricular end-diastolic pressure increased from 17 mmHg to 27 mmHg, while in Example A, the left ventricular end-diastolic pressure decreased from 19 mmHg to 10 mmHg, and in Example B, the left ventricular end-diastolic pressure decreased from 20 mmHg to 14 mmHg.

[0075] Furthermore, Example A, with an outer diameter of 13 Fr for the delivery vessel 4, was compared with Example B, with an outer diameter of 11 Fr. In Example B, the left ventricular end-diastolic pressure decreased by 6 mmHg before the pump was driven and between 3000 rpm, while in Example A, the decrease was 9 mmHg. The results showed that the larger diameter delivery vessel 4 could more effectively reduce cardiac load.

[0076] Meanwhile, the differences in left ventricular end-diastolic pressure between Example A, Example B, and the comparative example before the auxiliary circulation is started (before the pump is driven) are due to experimental error.

[0077] Industrial application

[0078] This invention can be used as a cannula in extracorporeal circulatory devices.

[0079] Explanation of symbols in the diagram

[0080] 1, 10, 11 Anterograde blood delivery cannula; 2, 20 Anterograde blood return section; 3, 4 Blood delivery vessels; 3a, 3b, 7a-7i Side holes; 5 Guidewire; 6 First blood return tube; 6a Extension section; 7, 71, 72 Second blood return tube; 8 Bag body; 9, 9a-9c Blood; 21 Pulsating circulation simulator; 22 Pneumatic actuator; 23 Left ventricle model; 24 Pressure loading chamber; 2 Mitral valve model; 26 Pulmonary vascular resistance; 27 Aortic valve model; 28 Catheter insertion port; 29 Ultrasonic flow meter; 30 Aorta model; 31 Venous reservoir; 32 Peripheral resistance; 70 Tip; 81 Heart; 82 Brain; 91 Descending aorta; 92 Aortic arch; 93 Ascending aorta; 94 Right subclavian artery; 95 Right common carotid artery; 96 Left common carotid artery; 97 Left subclavian artery; 98 Right coronary artery; 99 Left coronary artery.

Claims

1. A antegrade blood delivery cannula, the proximal end of which is placed within the ascending aorta and delivers blood supplied by an extracorporeal membrane oxygenation (ECMO) via the ascending aorta, the cannula comprising a delivery vessel located at the base of the cannula and connectable to the ECMO, and an antegrade blood return section located at the proximal end of the cannula. in, The antegrade blood return section includes: An antegrade blood return mechanism is used to reverse the blood flow from retrograde to antegrade and guide it towards the basal side; and A blood delivery pressure regulating mechanism is used to regulate the delivery pressure of the blood.

2. The antegrade blood delivery cannula according to claim 1, wherein, The antegrade blood return section is formed with a blood return tube, the front end of which is closed and at least two side holes are provided on the front end side; On the inner side of the front end of the blood return tube, a portion of a roughly hemispherical bag is adhered. The opening of the bag is positioned around the entire periphery of the blood return tube, including the side hole. In the antegrade blood return mechanism, the side hole opens when the blood delivery pressure exceeds a predetermined threshold; In the blood delivery pressure regulating mechanism, the blood delivery pressure is eased by the bag body.

3. The antegrade blood delivery cannula according to claim 2, wherein, The blood return tube is formed by bonding or screwing together a first blood return tube located at the base and a second blood return tube located at the tip. The front end of the first blood return tube has an extension portion, the diameter of which is smaller than that of the base end. When the blood delivery pressure does not exceed the specified threshold, the outer surface of the extension abuts against and blocks a portion of the opening of the bag. When the blood delivery pressure exceeds a specified threshold, the contact between the outer surface of the extension and a portion of the opening of the bag is released. In the antegrade blood return mechanism, when the abutment state is released, the flow path formed between the extension portion and a portion of the opening end of the bag can enhance the antegrade flow capability.

4. The antegrade blood delivery cannula according to claim 1, wherein, The antegrade blood return section is formed by extending the supply blood vessel. The antegrade blood return mechanism is formed by bending the front end of the extended blood delivery vessel into a U-shape, and the blood delivery pressure regulating mechanism has at least two side holes formed in the middle portion of the extended blood delivery vessel.

5. The antegrade blood delivery cannula according to any one of claims 3 or 4, wherein, A guide wire is provided inside the antegrade blood delivery cannula near the center of the shaft, extending longitudinally from the base end to the front end.

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