Drainage hole with function of preventing blood vessel from adhering to wall

Abstract

The utility model discloses a drainage hole with a function of preventing blood vessels from adhering to the wall. The drainage hole comprises a drainage hole body, an anti-injury block, a supporting ring, a drainage ditch and an arc-shaped cannula adhering face. A gap between every two adjacent damage blocks is a drainage ditch; each anti-damage block consists of an anti-damage table, an access slope, an access arc, an anti-damage arc I and an anti-damage arc II, wherein the anti-damage table is positioned at the upper part of the anti-damage block; the access slope is located outside the anti-damage block; the access arc is in transition connection between the access slope and the anti-damage table; the anti-damage arc I is positioned on the inner side of the anti-damage block; the anti-damage arcs II are located on the two sides of the anti-damage block. According to the utility model, the drainage holes can be effectively prevented from being blocked by endangium, so that the following problems are avoided: the treatment effect is reduced or even interrupted due to sudden drop of drainage quantity, and the life of a patient is endangered; due to the fact that drainage holes are blocked by endangium, the endangium is injured due to the high pressure difference between intravascular equipment and extracorporeal equipment; endovascular injury generates thrombus which endangers the life of a patient.

Description

Technical Field

[0001] This utility model belongs to the technical field of cannulation and drainage holes for medical devices such as ECMO, and relates to a drainage hole with the function of preventing blood vessel adhesion to the wall. Background Technology

[0002] Extracorporeal membrane oxygenation (ECMO) is a crucial treatment method that supports the breathing and circulation of patients with severe cardiopulmonary failure through extracorporeal circulation. It represents the pinnacle of critical care technology. With the widespread use of ECMO devices, during blood extraction, the vascular intima often adheres tightly to the drainage port of the ECMO cannula. The negative pressure during drainage causes congestion and damage to the vascular intima, easily leading to thrombosis and endangering the patient's life. Furthermore, if vascular intima adheres to the ECMO cannula's drainage port during treatment, it hinders the amount of blood extracted from the blood vessel, significantly reducing extracorporeal circulation flow, potentially leading to treatment interruption or even death.

[0003] Figure 1 This diagram illustrates the distribution of drainage holes on the outer wall of the catheter. The right side of the diagram shows the main guide hole for blood drainage. Drainage holes are arranged sequentially from the main guide hole to the left. Currently, the drainage holes are essentially four holes orthogonally arranged at equal intervals on the outer wall of the catheter. There is no height difference between the drainage holes and the outer wall of the catheter, and they are the same thickness as the catheter wall. During high drainage volumes, the vascular intima, under the negative pressure within the catheter, causes radial inward contraction of the vessel wall, increasing the probability of adhesion. Furthermore, because there is no height difference between the drainage holes and the outer wall of the catheter, during high drainage volumes, the vascular intima, under the negative pressure within the catheter, will adhere tightly to the outer wall of the catheter, resulting in adhesion and blockage of the drainage holes. Because there is no height difference between the drainage hole and the outer wall of the cannula, and they are of the same thickness, when the wall-adhering effect occurs, the vascular intima blocking the drainage hole will fill into the drainage hole under pressure. Since the wall of the drainage hole is relatively thin, it will cut through the vascular intima and cause damage when it is filled by the vascular intima. Damaged vascular intima is prone to thrombosis, endangering the patient's life.

[0004] Optimizing the structure and distribution of drainage holes in medical devices such as ECMO to improve drainage efficiency and prevent endothelial adhesion, thereby fundamentally avoiding blood drainage obstruction, endothelial damage, and thrombosis, has become an urgent problem to be solved in the use of catheter drainage. Utility Model Content

[0005] The purpose of this invention is to provide a drainage hole that can effectively prevent vascular intima adhesion, thereby fundamentally avoiding blood drainage obstruction, vascular intima damage, and thrombus formation, and has the function of preventing vascular adhesion.

[0006] The technical solution adopted in this utility model is as follows: the drainage hole includes a drainage hole body 1, a damage-preventing block 18, a support ring 8, a drainage groove 9, and an arc-shaped insertion tube contact surface 10, characterized in that:

[0007] The support ring 8 has a drainage hole 1 at its center, four anti-damage blocks 18 evenly distributed on the upper part, and an arc-shaped insertion tube contact surface 10 that is tightly connected to the outer wall of the insertion tube 15 at the lower part.

[0008] The gap between adjacent damaged blocks 18 is a drainage channel 9;

[0009] Each damage prevention block 18 is composed of a damage prevention platform 2, an entry / exit ramp 3, an entry / exit arc 4, a damage prevention arc I 6, and a damage prevention arc II 7; wherein:

[0010] Damage protection platform 2 is located on top of damage protection block 18;

[0011] The entrance / exit slope 3 is located outside the damage prevention block 18;

[0012] The entry / exit arc 4 serves as a transition connection between the entry / exit slope 3 and the damage prevention platform 2;

[0013] Anti-damage arc I6 is located inside the anti-damage block 18;

[0014] The anti-damage arc II7 is located on both sides of the anti-damage block 18.

[0015] The drainage hole 1 is a channel for guiding blood from the blood vessel into the cannula 15. The diameter 11 of the drainage hole is three-quarters of the diameter 12 of the support ring, which is 1.5 to 6.0 mm.

[0016] The anti-damage table 2 is designed to support and hold the vascular intima when the pressure inside the drainage cannula 15 is significantly lower than the blood pressure in the blood vessel. The increased pressure difference between the inside and outside of the cannula 15 causes the vascular intima to adhere tightly to the anti-damage table 2. The protrusion of the anti-damage table 2 inside the drainage hole increases the surface area, which helps prevent damage to the vascular intima in the event of adhesion. Simultaneously, it ensures that blood still has a drainage channel connected to the cannula 15 even when adhesion occurs. The height 14 of the anti-damage table can be selected in different heights to accommodate various cannula sizes 15 (15, 17, 19, 21, and 23f), ranging from 0.4 to 3.0 mm, ensuring smooth insertion and removal during surgical procedures and maximizing drainage volume.

[0017] The inlet / outlet ramp 3 is designed to facilitate clinical operation, providing a smoother operation when inserting and removing the cannula 15. It is designed in a circular shape to facilitate the insertion and removal of blood vessels. The slope of the inlet / outlet ramp 3 is 20–45°.

[0018] The inlet / outlet arc 4 is designed for ease of clinical operation, ensuring smooth insertion and removal of the cannula 15; simultaneously, the curvature of the inlet / outlet arc 4 will not damage the vascular intima in the event of apposition to the vessel wall. The radius of curvature of the inlet / outlet arc 4 is 0.5–6.0 mm.

[0019] The purpose of the anti-damage chamfer 5 is to prevent damage to the vascular endothelium when adhesion to the vessel wall occurs. The radius of the anti-damage chamfer 5 is 0.3–1.5 mm.

[0020] The curvature of the anti-damage arc I6 can improve the efficiency of blood entering the cannula 15 from the drainage groove 9 under high drainage volume. The radius of the anti-damage arc I6 is 0.3–1.5 mm.

[0021] The function of the anti-damage arc II 7 is to prevent damage to the vascular endothelium during insertion and removal of the cannula 15. Simultaneously, the curvature of the anti-damage arc 7 effectively prevents blood cells from violently colliding with the anti-damage platform 2 during the process of blood being drawn from the blood vessel into the cannula 15 under high drainage flow conditions, thus preventing blood cell damage. The radius of the anti-damage arc II 7 is 0.5–4.5 mm.

[0022] The function of the support ring 8 is to utilize the outer wall of the circular insertion tube 15 for support, evenly distributing the stress of the entire structure to the outer wall of the insertion tube 15, ensuring stability during medical surgical insertion and removal operations, as well as reliability during drainage. The width of the support ring 8 is approximately one-quarter of the diameter 12 of the support ring, approximately 0.5–3.0 mm. Meanwhile, the diameter 12 of the support ring is the maximum diameter of this invention when combined with the insertion tube 15, ranging from 2.0 to 8.0 mm.

[0023] The function of the drainage groove 9 is to guide blood from the blood vessel into the cannula 15. When the adhesion effect occurs, the vascular endothelium covers the top of the anti-damage platform 2, but the elasticity of the blood vessel wall prevents the blood vessel wall from completely covering the four vertical drainage grooves 9 and the entirety of each drainage groove 9. At this time, the uncovered drainage grooves 9 and the uncovered portions of the drainage grooves 9 can still continue to guide blood from the blood vessel into the cannula 15. Because there are always drainage grooves not covered by the vascular endothelium, blood always flows from the blood vessel into the cannula 15, making the pressure difference between the cannula 15 and the blood vessel insufficient to damage the vascular endothelium, thus reducing the destructive effect of the adhesion phenomenon. The width of the drainage groove 9 should ensure that the elastic bending of the blood vessel wall does not reach the bottom of the drainage groove when the adhesion effect occurs. Based on the principles of fluid mechanics and the elasticity simulation calculation of the blood vessel wall, combined with the outer wall curvature of the commonly used 15, 17, 19, 21 and 23f cannulas 15 currently on the market, the width of the drainage groove 9 is 0.2 to 3.0 mm.

[0024] The arc-shaped cannula contact surface 10 is the contact surface that tightly connects the present invention with the outer wall of the cannula 15. Its purpose is to provide sufficient support strength and stability for the present invention. The surface curvature should meet the curvature of the outer wall of the commonly used 15, 17, 19, 21 and 23f cannulas 15 on the market. Its curvature radius ranges from 2 to 12 mm. The contact surface height 13 is 0.4 to 1.5 mm.

[0025] By adopting the above structure, this utility model can effectively avoid the occurrence of vascular intima blockage of the drainage hole, i.e., the phenomenon of apposition to the wall, when using ECMO and other devices for drainage operations. This fundamentally avoids the following problems: 1. The sudden drop in drainage volume leads to a decrease or even interruption of the treatment effect, endangering the patient's life; 2. The vascular intima is injured due to the high pressure difference between the blood vessel and the external device caused by the blockage of the drainage hole by the vascular intima; 3. The vascular intima injury leads to thrombosis, endangering the patient's life. Attached Figure Description

[0026] Figure 1 A schematic diagram showing the distribution of existing drainage holes on the outer wall of the cannula;

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

[0028] Figure 3 for Figure 2 A bottom view;

[0029] Figure 4 for Figure 2 Side view;

[0030] Figure 5 This is a schematic diagram showing the distribution of the drainage holes on the outer wall of the insertion tube according to this utility model.

[0031] In the diagram: 1. Drainage hole body; 2. Damage-proof platform; 3. Inlet / outlet slope; 4. Inlet / outlet arc; 5. Damage-proof chamfer.

[0032] 6. Anti-damage arc I; 7. Anti-damage arc II; 8. Support ring; 9. Drainage groove; 10. Arc-shaped insertion tube mating surface;

[0033] 11. Drainage hole diameter; 12. Support ring diameter; 13. Fitting surface height; 14. Damage prevention platform height; 15. Insertion tube; 16. Drainage hole distribution distance; 17. Insertion tube main guide hole; 18. Damage prevention block. Detailed Implementation

[0034] like Figure 2 , Figure 3 , Figure 4As shown, the drainage hole of this utility model has a certain height, creating a height difference with the wall of the insertion cannula 15. The height of the drainage hole can obstruct the insertion and removal of the cannula during surgery. The structure of the inlet / outlet slope 3, the inlet / outlet arc 4, and the anti-damage arc II 7 reduces the obstruction during the insertion and removal of the insertion cannula 15.

[0035] The maximum diameter of the cannula 15 inserted into the blood vessel is smaller than that of a normal blood vessel. During normal surgery, blood between the vascular intima and the anti-damage table 2 is introduced into the cannula 15 through the drainage hole body 1 and the drainage groove 9. When blood flows through the structure of this invention, the curvature of the anti-damage chamfer 5, the anti-damage arc I 6, and the anti-damage arc II 7 can effectively prevent blood cells in the blood from colliding with each other during high-speed movement and from being damaged by collisions with the three-dimensional structure of this invention.

[0036] When the blood drainage volume increases, the vascular intima will adhere tightly to the surface of the anti-damage table 2. Even so, a large amount of blood will still flow into the cannula 15 through the drainage groove 9 perpendicular to the surface of the anti-damage table 2. The drainage groove 9 is orthogonal to the surface of the anti-damage table 2, thus it is less likely to be covered by the vascular intima. The presence of the drainage groove 9 ensures a connection between the cannula 15 and the blood vessel, resulting in a significantly higher pressure difference between the blood vessel and the cannula 15 when the vascular intima adheres tightly to the surface of the anti-damage table 2 compared to using a conventional cannula. This high pressure difference makes the blood drainage volume of this invention significantly higher than that of a conventional cannula under the same usage conditions. According to theoretical calculations and experimental simulations, the blood drainage volume is 20% to 50% higher under the same conditions.

[0037] As blood drainage volume increases further, the vascular intima will adhere tightly to the surface of the anti-damage table 2 and indent into the drainage hole and drainage groove 9. At this time, the curvature of the anti-damage chamfer 5 and the inlet / outlet arc 4 can effectively protect the vascular intima from being cut or damaged. Simultaneously, the drainage groove 9 remains unobstructed, ensuring uninterrupted blood drainage and that the pressure on the vascular intima does not exceed the value that would cause damage. The width and height design of the drainage groove 9, derived from elasticity calculations and experimental environment simulations, ensures that under normal operating conditions, the deformation of the vascular intima is insufficient to cause blockage of the drainage groove 9.

[0038] The structure of this invention has been tested in simulated environmental experiments and can ensure that the vascular endothelium is not damaged when the blood flow rate is not higher than 12L / min. Currently, the normal blood flow rate for surgery is around 3 to 10L / min.

[0039] like Figure 5As shown, this invention provides one to N drainage holes distributed along the drainage hole distribution distance 16 of the cannula 15, spaced at certain intervals and arranged in a spiral pattern. In use, the portion of the cannula 15 inserted into the blood vessel must at least include the position from the main guide hole 17 to the Nth drainage hole; that is, the main guide hole 17 to the Nth drainage hole should all enter the blood vessel. The radial distribution angle of the drainage holes along the cannula 15 is 40–60°, and the spiral distribution angle of the N drainage holes is 360–480°, i.e., spiraling 1–1.3 times radially along the cannula 15. The value of N is 9–13; for example, when the radial angle of the cannula 15 is 40°, the value of N is 13; when the radial angle of the cannula 15 is 60°, the value of N is 9. The value of N is required to satisfy the radial coverage range of the cannula 15 of 360 to 480° within the value of the drainage hole distribution distance 16. Since the drainage holes of this utility model are distributed in a spiral shape, the cannula 15 has drainage holes on all four sides of the axial direction to prevent blood vessels from sticking to the wall, ensuring that blood from all directions outside the cannula 15 has drainage holes to be introduced into the cannula 15.

[0040] The drainage hole distribution distance 16 refers to the distance from the main guide hole 17 of the intubation cannula to the drainage hole (i.e., the Nth one) that is farthest from the main guide hole 17. The drainage hole distribution distance 16 varies on different models of intubation cannulas 15, and the distance ranges from 40 to 400 mm.

Claims

1. A drainage hole with the function of preventing blood vessel adhesion to the wall, characterized in that: The drainage hole includes a drainage hole body (1), a damage prevention block (18), a support ring (8), a drainage groove (9), and an arc-shaped insertion cannula fitting surface (10). The support ring (8) has a drainage hole (1) at its center, four anti-damage blocks (18) are evenly distributed on the upper part, and an arc-shaped insertion tube contact surface (10) that is tightly connected to the outer wall of the insertion tube (15) at the lower part. The gap between the adjacent anti-damage blocks (18) is a drainage channel (9). Each damage prevention block (18) is composed of a damage prevention platform (2), an entry / exit ramp (3), an entry / exit arc (4), damage prevention arc I (6), and damage prevention arc II (7); wherein: The damage prevention table (2) is located above the damage prevention block (18); The entrance / exit slope (3) is located outside the damage prevention block (18); The entry / exit arc (4) is the transition connection between the entry / exit slope (3) and the damage prevention platform (2); The anti-damage arc I (6) is located inside the anti-damage block (18); The anti-damage arc II (7) is located on both sides of the anti-damage block (18).

2. A drainage hole with anti-vascular adhesion function according to claim 1, characterized in that: The diameter (11) of the drainage hole is three-quarters of the diameter (12) of the support ring, which is 1.5 to 6.0 mm; the height (14) of the anti-damage platform is 0.4 to 3.0 mm; the slope of the inlet / outlet slope (3) is 20 to 45°; the radius of the arc of the inlet / outlet arc (4) is 0.5 to 6.0 mm; the radius of the anti-damage chamfer (5) is 0.3 to 1.5 mm; the radius of the arc of anti-damage arc I (6) is 0.3 to 1.5 mm; the radius of the arc of anti-damage arc II (7) is 0.5 to 4.5 mm; and the width of the drainage ditch (9) is 0.2 to 3.0 mm.

3. A drainage hole with anti-vascular adhesion function according to claim 1, characterized in that: The width of the support ring (8) is one-quarter of the diameter of the support ring (12), which is 0.5 to 3.0 mm; the maximum diameter of the support ring (12) combined with the insertion tube (15) is in the range of 2.0 to 8.0 mm.

4. A drainage hole with the function of preventing blood vessel adhesion as described in claim 1, characterized in that: The radius of curvature of the arc-shaped insertion cannula contact surface (10) ranges from 2 to 12 mm; the height of the contact surface (13) is 0.4 to 1.5 mm.

5. A drainage hole with anti-vascular adhesion function according to claim 1, characterized in that: The 1 to N multiple drainage holes are distributed at a distance (16) on the insertion cannula (15), and they are distributed in a spiral shape with a distribution distance range of 40 to 400 mm.

6. A drainage hole with anti-vascular adhesion function according to claim 5, characterized in that: The radial distribution angle of the insertion tube (15) is 40 to 60°, and the N spiral distribution angles are 360 ​​to 480°, that is, the insertion tube (15) spirals 1 to 1.3 times radially; the value of N is 9 to 13.

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