A vascular embolization stent

Abstract

The present application relates to the field of medical devices, and specifically discloses a vascular embolization stent. A vascular embolization stent comprises a support portion and a balloon portion fixed to the support portion. The support portion comprises a plurality of support bodies, wherein the plurality of support bodies are wavy ring structures, and two adjacent support bodies are connected by a plurality of connecting rods. The support portion is sequentially coated with a procoagulant component and racemic polylactic acid (PDLLA), and the balloon portion is provided with a plurality of through holes. The vascular embolization stent in the present application can achieve controllable isolation of blood flow, allowing blood to gradually form a thrombus, ultimately completely embolizing the blood vessel, reducing the possibility of a stress reaction and minimizing harm to the human body.

Description

Technical Field

[0001] The present application relates to the field of medical devices, and more specifically, to a vascular embolization stent. Background Art

[0002] The ever-accelerating pace of life and increasing stress are accompanied by the onset of several diseases, among which vascular bleeding disorders, such as cerebral hemorrhage and aneurysms, are the most common. Currently, these diseases are primarily treated through interventional procedures, where embolic materials are implanted in the body to isolate blood flow in the target vessels. This is a common method for treating vascular bleeding or isolating blood supply to tumor tissue.

[0003] Commonly used vascular embolic materials include thrombi, gel microspheres, balloons, and coils. These materials have drawbacks such as difficulty in delivery and release, prone to shedding or displacement, and high cost. Furthermore, once implanted, these materials can momentarily stop blood flow, leading to stress reactions and potentially harmful effects. Summary of the Invention

[0004] In order to enable the vascular embolization material to slowly and steadily embolize the blood vessels, the present application provides a vascular embolization stent.

[0005] The present application provides a vascular embolization stent, which adopts the following technical solution:

[0006] A vascular embolization stent comprises a support portion and a balloon portion fixed to the support portion, wherein the support portion comprises a plurality of support bodies, wherein the plurality of support bodies are wavy ring structures, and two adjacent support bodies are connected by a plurality of connecting rods, wherein a procoagulant component and racemic polylactic acid (PDLLA) are sequentially coated on the support portion, and a plurality of through holes are opened on the balloon portion.

[0007] Preferably, the balloon portion is a spherical crown.

[0008] By adopting this technical solution, the support portion is composed of several corrugated ring-shaped support bodies. Two adjacent support bodies are connected by multiple connecting rods to form a cylindrical support portion with a hollow structure. The embolic stent is fixed to the delivery balloon in a compressed state and delivered to the target embolic vessel through an interventional procedure. The balloon is then expanded to expand the stent and secure it to the target vessel.

[0009] The inner wall of the support portion is coated with a procoagulant component and racemic polylactic acid (PDLLA). The procoagulant component primarily promotes thrombosis. The racemic polylactic acid (PDLLA) coats the procoagulant component, preventing it from instantaneously coming into contact with blood. This prevents instantaneous blood vessel blockage during stent implantation, thereby minimizing the stress response. Once the stent is implanted, blood flow continuously flushes the PDLLA until it degrades and disappears. Consequently, the procoagulant component is slowly released as the PDLLA degrades, gradually coming into contact with blood, leading to the formation of a thrombus and obstructing blood flow.

[0010] The racemic polylactic acid is preferably one of PDLLA-30, PDLLA-50, PDLLA-70 or PDLLA-100.

[0011] A balloon portion is fixedly attached to one end of the support portion. The balloon portion collects thrombi formed when procoagulant components come into contact with blood. The thrombi gradually accumulate on the balloon portion, blocking blood flow and achieving hemostasis. The balloon portion is a spherical cap, preferably a hemisphere, more preferably a hollow hemisphere; it can also be cylindrical or truncated cone-shaped.

[0012] The balloon portion is provided with a plurality of through-holes, including a first through-hole and a second through-hole. The first through-hole is provided on the centerline of the balloon portion and is provided for passage of an interventional guidewire and balloon. The second through-holes are provided around the first through-hole and can have varying diameters. The second through-holes function to facilitate blood circulation. The position and number of the second through-holes are adjusted based on the intended use of the vascular embolization stent, and the number of second through-holes can be zero.

[0013] The through-holes serve three purposes. First, they allow for the passage of interventional guidewires and balloons. Second, after the vascular embolization stent is implanted in the vessel, blood is allowed to circulate through the through-holes, reducing the possibility of a sudden blood flow cessation. Third, different through-hole sizes can be used to control the initial blood flow. The use of anticoagulants or antiplatelet drugs can also be used to regulate the speed of thrombosis, thereby controlling the duration of vascular embolization.

[0014] Preferably, the plurality of connecting rods are cylindrical, U-shaped or S-shaped.

[0015] By adopting the above technical solution, the connecting rod can be a cylinder, a U-shaped body or an S-shaped body. When the connecting rod is a cylinder, the length of the connecting rod is fixed. When the vascular embolization stent is in use, as the diameter of the vascular embolization stent increases, the height of the support body is gradually compressed, thereby gradually reducing the length of the vascular embolization stent. When the connecting rod is a U-shaped body or an S-shaped body, the length of the connecting rod can be adjusted. Therefore, not only can the diameter of the vascular embolization stent be increased, but the length of the vascular embolization stent can also be adjusted, thereby increasing the flexibility of the vascular embolization stent.

[0016] Preferably, the support portion and the balloon portion are integrally formed.

[0017] Preferably, the support portion and the balloon portion are formed by hot pressing.

[0018] By adopting the above technical solution, the support part is fixedly connected to the balloon part, and the balloon part is a spherical crown, and the protrusion direction of the spherical crown is away from one side of the support part. The support part and the balloon part are connected by one-piece molding or hot pressing. When the support part and the balloon part are made of the same material, the support part is connected by one-piece molding, which can increase the strength between the support part and the balloon part; when the support part and the balloon part are made of different materials, the material of the support part is 316L stainless steel, cobalt-nickel alloy or nickel-titanium alloy, and the material of the balloon part is nylon PA66, and the support part and the balloon part are hot pressed. First, the support part is prepared, and then the support part is placed in a mold, and finally the support part and the balloon part are connected by hot pressing.

[0019] Preferably, the length of the support portion is 5-50 mm.

[0020] Preferably, the diameter of the support portion is 2-6 mm, and the diameter of the balloon portion is consistent with that of the support portion.

[0021] By adopting the above technical solution, the diameter of normal blood vessels is generally 15mm for elastic arteries, approximately 6mm for muscular arteries, and approximately 37μm for arterioles. In this application, the diameters of the support portion and balloon portion are 2-6mm, and the diameter of the support portion can be increased by 20-35%. In other words, when the diameter of the support portion is 6mm, the diameter of the support portion can be increased to 7.2-8.1mm.

[0022] In the present application, the length of the support portion is 5-50 mm. Depending on the location of the blood vessel, the length of the support portion can also be greater than 50 mm, and the length can be adjusted in different usage positions.

[0023] When the balloon portion is a spherical cap, the diameter of the balloon portion is consistent with the diameter of the support portion, and the length of the balloon portion is the height of the spherical cap, which is 2-4 mm.

[0024] When the balloon portion is a hollow hemisphere, the diameter of the balloon portion is consistent with the diameter of the support portion, and the length of the balloon portion is the radius of the hollow hemisphere, which is 2-6 mm.

[0025] When the balloon portion is a cylinder or a frustum, the diameter of the balloon portion is consistent with the diameter of the support portion, and the length of the balloon portion is the thickness of the cylinder or the frustum, which is 1-2 mm.

[0026] Preferably, the support portion and the balloon portion are made of 316L stainless steel, cobalt-nickel alloy or nickel-titanium alloy.

[0027] By adopting the above technical solution, the materials used for the support part and the balloon part are 316L stainless steel, cobalt-nickel alloy or nickel-titanium alloy. Among them, 316L stainless steel is a commonly used material for making vascular embolization stents, and 316L stainless steel has good toughness and wear resistance; while cobalt-nickel alloy or nickel-titanium alloy is often used as a material for making teeth, and cobalt-nickel alloy or nickel-titanium alloy also has excellent wear resistance and good compatibility. When the vascular embolization stent made of 316L stainless steel, cobalt-nickel alloy or nickel-titanium alloy is implanted in a blood vessel, it causes less harm to the human body and can be fixed in the human body for a long time or permanently.

[0028] The preparation process of the vascular embolization stent uses laser cutting technology to cut the material into semi-finished products, clean the semi-finished products, heat treat them to change their properties, and then polish and clean them; the inner wall of the support part is coated with a pro-coagulant component and racemic polylactic acid PDLLA in sequence, and finally sterilized and packaged.

[0029] Preferably, the support portion and the balloon portion are made of poly-L-lactic acid (PLLA).

[0030] By adopting the above technical solution, in this application, the support portion and balloon portion are made of poly (L-lactic acid) (PLLA) and produced using 3D printing technology. PLLA is a biodegradable material that will gradually degrade over time, reducing long-term harm to the human body.

[0031] Preferably, the material of the balloon portion is a medical polymer material, and the medical polymer material is medical-grade polyethylene, polypropylene, polyoxymethylene, polycarbonate or nylon.

[0032] By adopting the above technical solution, the balloon is made of non-degradable medical polymer materials, including medical-grade polyethylene, polypropylene, polyoxymethylene, polycarbonate, or nylon. When the balloon is made of medical-grade nylon, PA66 or PA6 is selected.

[0033] Preferably, the accelerating component is kaolin, quartz powder or silica powder.

[0034] By adopting the above technical solution, the primary component of kaolin, quartz powder, and silica powder is SiO2. When SiO2 comes into contact with blood, it absorbs water from the blood, concentrating platelets and thrombin, causing coagulation factors and platelets to aggregate and deposit, forming a thrombus and rapidly stopping bleeding. Therefore, coating the pro-coagulant component with a layer of racemic polylactic acid (PDLLA) allows the kaolin, quartz, and silica powders to slowly release their properties, achieving slow hemostasis. Kaolin, quartz, and silica powders can rapidly stop bleeding when in contact with blood without exothermicity, thus minimizing thermal damage to tissues and ensuring safety.

[0035] In summary, this application has the following beneficial effects:

[0036] 1. The vascular embolization stent of the present application comprises a support portion and a balloon portion. The support portion primarily serves as a support. The inner wall of the support portion is sequentially coated with a procoagulant component and racemic polylactic acid (PDLLA), which can gradually form a thrombus. The balloon portion serves to isolate blood flow and aggregate thrombi, thereby reducing the possibility of a stress reaction.

[0037] 2. The material of the support part in this application is preferably poly-L-lactic acid (PLLA), which is degradable and less harmful to the human body;

[0038] 3. The vascular embolization stent of the present application is simple to deliver and release, and is less likely to fall off or shift. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a front view of the vascular embolization stent in this application;

[0040] Figure 2 A bottom view of the vascular embolization stent in this application;

[0041] Figure 3 This is a schematic diagram of the vascular embolization stent implanted into a blood vessel in this application;

[0042] In the figure, 1, support part; 11, support body; 12, connecting rod; 2, balloon part; 21, through hole; 211, first through hole; 212, second through hole; 3, balloon; 4, inner wall of blood vessel; 5, interventional guidewire. DETAILED DESCRIPTION

[0043] The present application is further described in detail below with reference to the accompanying drawings and examples.

[0044] Example 1

[0045] Reference Figure 1 and Figure 2In the present application, the vascular embolization stent includes a support portion 1 and a balloon portion 2, wherein the support portion 1 includes fourteen support bodies 11. The support bodies 11 are wavy ring structures, each of which consists of sixteen wave crests and sixteen wave troughs. Every two adjacent support bodies 11 are connected by three connecting rods 12, which are fixed to the wave crests of two adjacent support bodies 11. The three connecting rods 12 are evenly distributed, and the angle between each two connecting rods 12 is 120 degrees. The connecting rods 12 are cylindrical. In other embodiments, the connecting rods 12 are U-shaped or S-shaped.

[0046] The balloon portion 2 is fixedly connected to one end of the support portion 1, and the balloon portion 2 is a spherical crown. In other embodiments, the balloon portion 2 is a hemisphere, a hollow hemisphere, a cylinder or a truncated cone. The convex direction of the spherical crown is away from the direction of the support portion 1. The crest of the support body 11 is fixedly connected to the spherical crown, and the support body 11 has the same diameter as the spherical crown. A first through hole 211 and six second through holes 212 are provided on the spherical crown. The first through hole 211 is located at the highest point of the spherical crown protrusion, and the first through hole 211 coincides with the central axis of the balloon portion 2. The first through hole 211 is large enough for the balloon 3 and the interventional guide wire 5 to pass through. The function of the second through hole 212 is to enable blood to circulate after the vascular embolization stent is implanted. The position and number of the second through holes 212 can be opened according to the use location or requirements.

[0047] The inner wall of the support portion 1 is sequentially coated with a procoagulant component and racemic polylactic acid (PLLA) (PDLLA). The procoagulant component primarily causes blood to form a thrombus, thereby blocking blood flow. The procoagulant component is kaolin, quartz powder, or silica powder. Racemic polylactic acid (PLLA) (PDLLA) can delay the release of the procoagulant component. When the vascular embolization stent is implanted in a blood vessel, the procoagulant component is encapsulated by the PDLLA and cannot be immediately released. This prevents blood flow from being immediately stopped, reducing the risk of stress reactions and other complications.

[0048] When the support portion 1 and the balloon portion 2 are both made of 316L stainless steel, cobalt-nickel alloy, or nickel-titanium alloy, the support portion 1 and the balloon portion 2 are integrally formed and prepared by laser cutting. In other embodiments, when the support portion 1 and the balloon portion 2 are both made of poly (L-lactic acid) PLLA, the support portion 1 and the balloon portion 2 are integrally formed and prepared by 3D printing technology. In other embodiments, when the support portion 1 is made of 316L stainless steel, cobalt-nickel alloy, nickel-titanium alloy, or poly (L-lactic acid) PLLA, and the balloon portion 2 is made of PA66, the support portion 1 and the balloon portion 2 are prepared by hot pressing.

[0049] The length of the support portion 1 in the vascular embolization stent is 15 mm. In other embodiments, the length of the support portion 1 is 24 mm, 35 mm, or 50 mm. The diameter of the support portion 1 and the balloon portion 2 is 4 mm. In other embodiments, the diameter of the support portion 1 and the balloon portion 2 is 6 mm.

[0050] Reference Figure 3 When the vascular embolization stent is implanted in the blood vessel, the balloon 3 and the interventional guide wire 5 pass through the first through hole 211 on the balloon part 2 and extend all the way to the end of the support part 1 away from the drug part 2. The balloon 3 will gradually expand after being inflated. When the balloon 3 is inflated, the balloon 3 expands and squeezes the support part 1 in the direction away from the central axis of the support part 1. At this time, the crest and trough on the support body 11 move towards each other along the direction of their own central axis. In other words, the crest moves toward the trough, and the trough moves toward the crest, which can cause the support body 11 to move in the direction away from the center of the circle along its own radial direction, thereby increasing the diameter of the support body 11. The support body 11 gradually moves until it abuts against the inner wall 4 of the blood vessel, causing the blood vessel to gradually expand, and the blood vessel expansion ratio is 1:1.2. The balloon part 2 is a hollow hemisphere, and the material is PA66, which can expand and contract freely. Finally, the vascular embolization stent is in a state of being larger at the top and smaller at the bottom.

[0051] When one end of the support portion 1 away from the balloon portion 2 abuts against the inner wall 4 of the blood vessel, the gas inside the balloon 3 is gradually exhausted, and the balloon 3 and the interventional guide wire 5 are removed from the vascular embolization stent. Since the support portion 1 is plastically deformed, after the balloon 3 is removed, it still maintains a larger upper portion and smaller lower portion state, and is firmly fixed on the inner wall 4 of the blood vessel. At this time, blood flows through the first through hole 211 and the second through hole 212, and the vascular embolization stent will not stop the blood flow instantly. As time goes by and the blood is flushed, the PDLLA on the inner wall of the support portion 1 gradually degrades or falls off, allowing the procoagulant components to come into direct contact with the blood. A thrombus is formed to block the first through hole 211 and the second through hole 212 on the balloon portion 2. The thrombus gradually accumulates on the balloon portion 2, thereby blocking the blood vessel and stopping the blood flow, achieving the purpose of hemostasis.

[0052] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A vascular embolization stent, characterized in that: The invention comprises a support portion (1) and a balloon portion (2) fixed to the support portion (1), wherein the support portion (1) comprises a plurality of support bodies (11), wherein the plurality of support bodies (11) are of a wave-shaped ring structure, and two adjacent support bodies (11) are connected by a plurality of connecting rods (12). The support portion (2) is coated with a coagulant component and racemic polylactic acid (PDLLA) in sequence, and the balloon portion (2) is provided with a plurality of through holes (21). The diameter of the support portion (1) is 2-6 mm, and the diameter of the balloon portion (2) is consistent with that of the support portion (1). The coagulant component is kaolin, quartz powder or silica powder.

2. The vascular embolization stent according to claim 1, characterized in that: The balloon portion (2) is a spherical crown.

3. The vascular embolization stent according to claim 1, characterized in that: The plurality of connecting rods (12) are cylindrical, U-shaped or S-shaped.

4. The vascular embolization stent according to claim 1, characterized in that: The support portion (1) and the balloon portion (2) are integrally formed.

5. The vascular embolization stent according to claim 1, characterized in that: The length of the support portion (1) is 5-50 mm.

6. The vascular embolization stent according to any one of claims 1 to 5, characterized in that: The support portion (1) and the balloon portion (2) are made of 316L stainless steel, cobalt-nickel alloy or nickel-titanium alloy.

7. The vascular embolization stent according to any one of claims 1 to 5, characterized in that: The support part (1) and the balloon part (2) are made of poly (L-lactic acid) (PLLA).

8. The vascular embolization stent according to any one of claims 1 to 5, characterized in that: The material of the balloon part (2) is a medical polymer material, and the medical polymer material is medical-grade polyethylene, polypropylene, polyoxymethylene, polycarbonate or nylon.

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