An extracorporeal membrane oxygenation arteriovenous cannula that is easily placed over a puncture guide wire

Abstract

The utility model relates to a kind of medical instruments, especially a kind of extracorporeal membrane oxygenation arteriovenous cannula easily placed by puncture guide wire. Including cannula body and inner core assembly, the steel wire with interval division is equipped in the cannula body wall, to enhance its anti-collapse ability, inner core assembly is set in the inside of the cannula body, and inner core assembly includes outer tube, inner tube, collapsible guide structure, first handle and second handle, the outer tube is set in the inner cavity of the cannula body, the inner tube is movably equipped in the outer tube, and the outer tube and the one end of the inner tube are respectively connected the first handle and the second handle. The utility model is by setting collapsible guide structure, play good guiding effect in cannula pushing process, effectively reduce the situation that cannula is stuck outside blood vessel wall, especially suitable for complex situation that skin tenacity is big, subcutaneous tissue is thick or puncture angle is big, significantly improve the success rate of cannulation.

Description

Technical Field

[0001] This utility model relates to a medical device, and more particularly to an extracorporeal membrane oxygenation (ECMO) arteriovenous cannula that is easily inserted via a puncture guidewire. Background Technology

[0002] Extracorporeal membrane oxygenation (ECMO) arteriovenous cannulation is a crucial pathway connecting extracorporeal circulation to the body's arteries and veins, facilitating the drainage of hypoxic blood and the reinfusion of oxygen-rich blood. The Seldinger puncture method is the commonly used approach for ECMO arteriovenous cannulation. It involves inserting a guidewire into the blood vessel through a puncture needle, then using a dilator to expand the guidewire before inserting the cannula with its inner core into the vessel. The inner core is then removed, and the cannula is clamped and connected to the extracorporeal circulation system. Because ECMO initiation time is often tight, especially during cardiopulmonary arrest, cannulation time should not be too long. Unsuccessful cannulation can easily lead to massive bleeding, and repeated dilation can cause vascular damage, increasing the difficulty of subsequent vascular repair. These factors place higher demands on ECMO arteriovenous cannulation.

[0003] When inserting a stent with a guidewire during the final stage of arteriovenous catheterization, the inner core is often smaller than the catheter itself due to the thickness of the catheter wall. This frequently results in the inner core being able to enter the blood vessel, but the catheter becoming stuck outside the vessel wall, making it difficult for the arteriovenous catheter to penetrate. This situation is particularly common when the skin is tough, the subcutaneous tissue is thick, or when puncturing the femoral artery and vein below the inguinal ligament. It also frequently occurs when the angle at which the puncture needle and guidewire enter the blood vessel is too large. Utility Model Content

[0004] To overcome the common problem that the inner core can enter the blood vessel, but the cannula gets stuck outside the blood vessel wall, making it difficult for arteriovenous cannulas to enter the blood vessel, this utility model provides an extracorporeal membrane oxygenation (ECMO) arteriovenous cannula that is easy to insert via a puncture guidewire.

[0005] The technical solution is as follows: An extracorporeal membrane oxygenation (ECMO) arteriovenous cannula that is easily inserted via a puncture guidewire includes a cannula body and an inner core assembly. The cannula body has spaced steel wires in its wall to enhance its anti-collapse capability. The inner core assembly is located inside the cannula body and includes an outer tube, an inner tube, a retractable guide structure, a first handle, and a second handle. The outer tube is located in the cavity of the cannula body, and the inner tube is movably disposed inside the outer tube. One end of the outer tube and the inner tube are respectively connected to the first handle and the second handle. The retractable guide structure includes an arc-shaped guide plate and a connecting rod. At least three arc-shaped guide plates are circumferentially spaced at the other end of the inner tube. The other end of the outer tube is circumferentially spaced and movably connected with the connecting rods, which are equal in number and correspond one-to-one with the number of arc-shaped guide plates. The other end of the connecting rod is hinged to the inner side of the arc-shaped guide plate.

[0006] Optionally, a connecting component is provided between the first handle and the second handle. The connecting component includes a rotating ring and a locking rod. The rotating ring is rotatably connected to the outer side of the second handle near the first handle. Two locking rods are symmetrically connected to the rotating ring. Cross grooves that are adapted to the locking rods are symmetrically opened at the end of the first handle near the second handle.

[0007] Optionally, the first handle is provided with a clamping assembly for fixing the cannula body. The clamping assembly includes an elastic clamp, a limiting cylinder and a spring. Multiple elastic clamps are circumferentially connected to one end of the first handle away from the second handle. The limiting cylinder is slidably provided on the outer side of the multiple elastic clamps. The spring is connected between the limiting cylinder and the first handle. A gap is provided between the limiting cylinder and the elastic clamp for the cannula body to be inserted.

[0008] Optionally, the elastic clamp has a beveled part on the outer side of one end near the first handle to facilitate the sliding and squeezing of the limiting cylinder, and an anti-slip part on the outer side of the other end to enhance the clamping friction and prevent relative movement of the insertion tube.

[0009] Optionally, the arc-shaped guide plate is made of titanium alloy, and the inner diameter of the multiple arc-shaped guide plates after unfolding is slightly larger than the cannula body by 1-2 mm, and wraps around the front end of the cannula body.

[0010] Optionally, the first handle and the elastic clamp are integrally injection molded structures, which improves the overall strength and manufacturing efficiency.

[0011] The beneficial effects of this invention are as follows: By setting a retractable guiding structure, this invention provides excellent guidance during cannulation, effectively reducing the likelihood of the cannula getting stuck outside the blood vessel wall. It is particularly suitable for complex situations involving tough skin, thick subcutaneous tissue, or large puncture angles, significantly improving the success rate of cannulation. The inner core assembly uses an outer tube in conjunction with an inner tube, and the expansion and contraction of the retractable guiding structure are controlled by a handle, allowing doctors to flexibly control the cannulation process, avoiding vascular damage caused by blind operation and reducing the risk of intraoperative and postoperative complications. The inner core assembly can be safely withdrawn after cannulation. A clamping assembly consisting of an elastic clamp and a limiting cylinder securely fixes the cannula body, and the anti-slip part further enhances friction, ensuring no relative sliding between the cannula and the inner core assembly, improving operational stability. The first and second handles are axially locked through a rotating ring and a locking rod with a cross groove, resulting in a simple structure and convenient operation, ensuring stable connection of all components during puncture and cannulation, preventing them from easily falling off. Attached Figure Description

[0012] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0013] Figure 2 This is a three-dimensional structural diagram of the front end of the inner core component of this utility model.

[0014] Figure 3 This is a three-dimensional structural diagram of the rear end of the core component of this utility model.

[0015] Figure 4 This is an exploded view of a partial structure of this utility model.

[0016] Explanation of reference numerals in the attached drawings: 1: Cannula body, 2: Outer tube, 3: Inner tube, 4: Arc-shaped guide plate, 5: Connecting rod, 6: First handle, 7: Second handle, 8: Rotary ring, 9: Locking rod, 10: Cross groove, 11: Elastic clamping plate, 111: Beveled part, 112: Anti-slip part, 12: Limiting cylinder, 13: Spring. Detailed Implementation

[0017] The embodiments of this utility model will be described below with reference to the accompanying drawings.

[0018] An easily insertable extracorporeal membrane oxygenation (ECMO) arteriovenous cannula via a puncture guidewire, such as Figures 1-4 As shown, the device includes an insertion cannula body 1 and an inner core assembly. The insertion cannula body 1 has spaced steel wires in its wall to enhance its anti-collapse capability. The inner core assembly is located inside the insertion cannula body 1 and can move within it. The inner core assembly includes an outer tube 2, an inner tube 3, a retractable guide structure, a first handle 6, and a second handle 7. The outer tube 2 is located within the cavity of the insertion cannula body 1, and the inner tube 3 is movably mounted inside the outer tube 2. Both the inner tube 3 and the outer tube 2 are circular tubes, and they can only slide relative to each other axially, not circumferentially. The rear ends of the outer tube 2 and the inner tube 3 are respectively connected to the first handle 6 and the second handle 7, with the first handle 6 located in front of the second handle 7. On the side, the retractable guide structure includes an arc-shaped guide plate 4 and connecting rods 5. Four arc-shaped guide plates 4 are circumferentially spaced on the outer wall of the front end of the inner tube 3. The arc-shaped guide plates 4 are made of titanium alloy. The front end of the arc-shaped guide plate 4 is smaller than the rear end. The inner diameter of the multiple arc-shaped guide plates 4 after unfolding is 1.5 mm larger than the outer diameter of the cannula body 1, and they wrap around the front end of the cannula body 1. Four connecting rods 5 are circumferentially hinged to the front end of the outer tube 2. The four connecting rods 5 correspond one-to-one with the four arc-shaped guide plates 4. The other end of the connecting rod 5 is hinged to the middle of the inner side of the arc-shaped guide plate 4. When the four arc-shaped guide plates 4 are unfolded to the maximum angle, the inner diameter of their rear end is larger than the diameter of the cannula body 1.

[0019] Furthermore, a connecting component is provided between the first handle 6 and the second handle 7. The connecting component includes a rotating ring 8 and a locking rod 9. The rotating ring 8 is rotatably connected to the outer front end of the second handle 7. Two locking rods 9 are symmetrically connected to the rotating ring 8. The rear end of the first handle 6 has symmetrically opened cross grooves 10 that are adapted to the locking rods 9. A damping structure is provided between the rotating ring 8 and the second handle 7. When the locking rod 9 is engaged in the cross groove 10, the damping structure can prevent the rotating ring 8 from rotating arbitrarily, ensuring the stability of the connection between the first handle 6 and the second handle 7.

[0020] Furthermore, the first handle 6 is provided with a clamping assembly for fixing the cannula body 1. The clamping assembly includes an elastic clamping plate 11, a limiting cylinder 12, and a spring 13. Five elastic clamping plates 11 are circumferentially connected to the front end of the first handle 6. The first handle 6 and the elastic clamping plates 11 are integrally injection molded, which improves the overall strength and manufacturing efficiency. The five elastic clamping plates 11 form a cylindrical shape. The limiting cylinder 12 is slidably provided on the outer side of the five elastic clamping plates 11. A spring 13 is connected between the limiting cylinder 12 and the first handle 6. The spring 13 is sleeved on the outer side of the five elastic clamping plates 11. A gap is provided between the inner side of the limiting cylinder 12 and the outer side of the elastic clamping plate 11 for the insertion of the cannula body 1.

[0021] Furthermore, the elastic clamp 11 has a beveled portion 111 on the outer side of one end near the first handle 6 to facilitate the sliding and squeezing of the limiting cylinder 12. The other end has an anti-slip portion 112 on the outer side, with a rubber strip on the anti-slip portion 112 to enhance the clamping friction and prevent relative movement of the insertion tube. When the limiting cylinder 12 squeezes the beveled portion 111 of the elastic clamp 11, the gap between the limiting cylinder 12 and the elastic clamp 11 is greater than the wall thickness of the insertion tube body 1. When the limiting cylinder 12 does not squeeze the beveled portion 111 of the elastic clamp 11, the gap is less than the wall thickness of the insertion tube body 1.

[0022] Before use, the inner core assembly is connected to the cannula body 1. The specific operation is as follows: push the limiting cylinder 12 in the clamping assembly towards the first handle 6, compressing the spring 13. At this time, the limiting cylinder 12 presses against the inclined surface 111 of the elastic clamping plate 11, causing multiple elastic clamping plates 11 to elastically contract towards the center, thereby increasing the gap between the clamping cylinder 12 and the elastic clamping plate 1. When inserting the cannula body 1 into this gap, sufficient space should be left for the first handle 6 to be pushed forward. Then release the limiting cylinder 12; under the rebound force of the spring 13, the limiting cylinder 12 returns to its original position, and the elastic clamping plate 11 also returns to its original position and clamps the cannula body 1, achieving a secure fixation. The anti-slip part 112 further enhances friction, ensuring no relative displacement between the cannula body 1 and the inner core assembly. The first handle 6 and the second handle 7 are locked together via a connecting assembly. During operation, insert the lever 9 into the center of the cross groove 10, then rotate the rotating ring 8 to position the lever 9 in the side groove of the cross groove 10. At this point, the first handle 6 and the second handle 7 cannot move axially, allowing for puncture. After successful puncture, insert a long guidewire through the puncture needle and gradually dilate the blood vessel along the guidewire until it matches the size of the cannula body 1. Subsequently, the cannula body 1, along with the inner core assembly, is inserted into the blood vessel along the guidewire. The retractable guiding structure guides the insertion during this process, ensuring the cannula body 1 enters the blood vessel smoothly. Once the tip of the cannula body 1 reaches the predetermined depth, first release the clamping assembly to release the fixation between the first handle 6 and the cannula body 1; then push the first handle 6 forward, moving the second handle 7, outer tube 2, inner tube 3, and retractable guiding structure forward together, allowing the retractable guiding structure to exit the cannula body 1 from the tip. Next, rotate the rotating ring 8 to return the lever 9 to the crossed position of the cross groove 10. Then, continue pushing the second handle 7 forward, moving the inner tube 3 forward. The connecting rod 5 then moves, causing the arc-shaped guide plate 4 to retract towards the center. The entire retractable guide structure shrinks to a size smaller than the inner diameter of the cannula body 1, facilitating subsequent withdrawal. Apply pressure again to the limiting cylinder 12, compressing the spring 13 and disengaging it from the inner wall of the cannula body 1. At this point, the inner core assembly can be completely extracted from the cannula body 1. The cannula body 1 then continues to advance along the guidewire to the target blood vessel, completing the final cannulation procedure.

[0023] If another puncture is required, simply reinsert the inner core assembly from the tail end of the cannula body 1, allowing the retractable guide structure to return to the front end of the cannula body 1. Push the second handle 7 to move the inner tube 3 backward, and slide the lever 9 backward along the cross groove 10. When the lever 9 reaches the intersection of the cross groove 10, rotate the rotating ring 8 to unfold the retractable guide structure to slightly larger than the inner diameter of the cannula body 1. Then pull the first handle 6 backward, causing the second handle 7 and the retractable guide structure to move backward synchronously, so that the guide structure is fitted onto the outside of the front end of the inner tube 3. Finally, use the clamping assembly to re-fix the first handle 6 to the cannula body 1, and the next puncture operation can be performed.

[0024] Although this disclosure has been shown and described with reference to specific exemplary embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made to this disclosure without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents. Therefore, the scope of this disclosure should not be limited to the above embodiments, but should be defined not only by the appended claims, but also by their equivalents.

Claims

1. A readily insertable extracorporeal membrane oxygenation (ECMO) arteriovenous cannula via a puncture guidewire, characterized in that, The device includes an insertion tube body and an inner core assembly. The insertion tube body has spaced steel wires in its wall. The inner core assembly is located inside the insertion tube body and includes an outer tube, an inner tube, a retractable guide structure, a first handle, and a second handle. The outer tube is located inside the cavity of the insertion tube body, and the inner tube is movably disposed inside the outer tube. One end of the outer tube and the inner tube are respectively connected to the first handle and the second handle. The retractable guide structure includes an arc-shaped guide plate and a connecting rod. At least three arc-shaped guide plates are circumferentially spaced at the other end of the inner tube. The other end of the outer tube is circumferentially spaced and movably connected with a number of connecting rods equal to and corresponding one-to-one with the number of arc-shaped guide plates. The other end of the connecting rod is hinged to the inner side of the arc-shaped guide plate.

2. The extracorporeal membrane oxygenation (ECMO) arteriovenous cannula that is easily inserted via a puncture guidewire according to claim 1, characterized in that, A connecting component is provided between the first handle and the second handle. The connecting component includes a rotating ring and a locking rod. The rotating ring is rotatably connected to the outer side of the second handle near the first handle. Two locking rods are symmetrically connected to the rotating ring. Cross grooves that are adapted to the locking rods are symmetrically opened at the end of the first handle near the second handle.

3. The extracorporeal membrane oxygenation (ECMO) arteriovenous cannula that is easily inserted via a puncture guidewire according to claim 2, characterized in that, The first handle is provided with a clamping assembly for fixing the cannula body. The clamping assembly includes an elastic clamp, a limiting cylinder and a spring. Multiple elastic clamps are circumferentially connected to the end of the first handle away from the second handle. The limiting cylinder is slidably provided on the outer side of the multiple elastic clamps. The spring is connected between the limiting cylinder and the first handle. A gap is provided between the limiting cylinder and the elastic clamp for the cannula body to be inserted.

4. The extracorporeal membrane oxygenation (ECMO) arteriovenous cannula that is easily inserted via a puncture guidewire according to claim 3, characterized in that, The elastic clamp has a beveled part on the outer side of one end near the first handle to facilitate the sliding and squeezing of the limiting cylinder, and an anti-slip part on the outer side of the other end to enhance the clamping friction and prevent relative movement of the insertion tube.

5. The extracorporeal membrane oxygenation (ECMO) arteriovenous cannula that is easily inserted via a puncture guidewire according to claim 4, characterized in that, The arc-shaped guide plate is made of titanium alloy. The inner diameter of the multiple arc-shaped guide plates after unfolding is slightly larger than the insertion tube body by 1-2 mm, and they wrap around the front end of the insertion tube body.

6. The extracorporeal membrane oxygenation (ECMO) arteriovenous cannula that is easily inserted via a puncture guidewire according to claim 5, characterized in that, The first handle and the elastic clamp are integrally injection molded structures.

Images