Spring ring for embolism

Abstract

The spring ring for embolism comprises a spring ring body and a wrapping extrusion wire, the spring ring body is of a hollow structure with two open ends to form an inner cavity, the wrapping extrusion wire is arranged in the spring ring body in a penetrating mode, and the wrapping extrusion wire comprises a nickel-titanium alloy wire core and a hydrogel layer wrapping the nickel-titanium alloy wire core. The nickel-titanium alloy wire core and the hydrogel layer extend in the length direction of the spring ring body, the nickel-titanium alloy wire core has a shape memory form, and the austenite transformation completion temperature of the nickel-titanium alloy wire core is larger than or equal to 28 DEG C and smaller than or equal to 32 DEG C so that the nickel-titanium alloy wire core can recover the shape memory form at the human body temperature. The wrapping extrusion wire is arranged in the spring ring body in the penetrating mode and comprises the nickel-titanium alloy wire core and the hydrogel layer wrapping the nickel-titanium alloy wire core, the basket forming performance of the spring ring can be greatly improved, the spring ring can be effectively attached to the inner wall of an aneurysm cavity, harm of nickel ions to a human body can be effectively avoided, and the structure is simple.

Description

Technical Field

[0001] This utility model relates to the field of medical devices, and in particular to a spring coil for embolization. Background Technology

[0002] Coil embolization is an important treatment for intracranial aneurysms and arteriovenous malformations. This technique involves creating a channel within the blood vessel through interventional surgery, and under the guidance of DSA (digital subtraction angiography), a catheter is superselectively placed into the aneurysm cavity. Coils are then delivered through the catheter to fill the aneurysm cavity, inducing thrombus formation and achieving aneurysm occlusion, preventing rupture due to blood flow impact. Coil embolization is minimally invasive, has a rapid recovery time, and is suitable for elderly, frail patients, or patients with multiple underlying diseases. It avoids the need for open craniotomy. Studies show that coil embolization can achieve an immediate aneurysm occlusion rate of approximately 90%, effectively reducing the risk of aneurysm rupture.

[0003] Despite its numerous advantages, coil embolization still has certain limitations with current technology. During coil delivery for embolization, a coil with a complex three-dimensional shape (also known as a three-dimensional coil) needs to be delivered into the aneurysm cavity first to form a stable three-dimensional framework structure within the cavity, providing support for subsequent coil packing. This ability to form a stable framework structure is called basketing ability. Currently, most commercially available coils are made of platinum-tungsten alloy. Due to limitations in flexibility, insufficient shape memory, and a lack of internal support, the three-dimensional coils exhibit insufficient basketing ability and cannot effectively adhere to the aneurysm cavity wall. This results in ineffective and uneven distribution of subsequent coils, increasing the recurrence rate of aneurysms and the risk of intracranial hemorrhage. Summary of the Invention

[0004] The purpose of this invention is to provide a spring coil for embolization to solve the problem of insufficient basket-forming properties of existing spring coils.

[0005] To achieve the above objectives, this utility model provides a spring coil for embolization, comprising a spring coil body and a coated extruded filament. The spring coil body has a hollow structure with openings at both ends to form an inner cavity. The coated extruded filament is inserted into the spring coil body. The coated extruded filament includes a nickel-titanium alloy wire core and a hydrogel layer covering the nickel-titanium alloy wire core. Both the nickel-titanium alloy wire core and the hydrogel layer extend along the length direction of the spring coil body. The nickel-titanium alloy wire core has a shape memory morphology. The austenite transformation completion temperature of the nickel-titanium alloy wire core is greater than or equal to 28 degrees and less than or equal to 32 degrees to recover the shape memory morphology at human body temperature.

[0006] Preferably, the hydrogel layer expands and fills the inner cavity of the spring coil body.

[0007] Preferably, an anti-unwinding wire is also provided in the spring coil body, and the anti-unwinding wire extends along the length direction of the spring coil body.

[0008] Preferably, the anti-unwinding filament is made of polypropylene.

[0009] Preferably, the ends of the spring coil body, the covered extruded filaments, and the anti-unwinding filaments are connected by a ball head, which covers the ends of the spring coil body, the covered extruded filaments, and the anti-unwinding filaments.

[0010] Preferably, the ball head is made of UV adhesive.

[0011] Preferably, the coated extruded filament is located in the middle of the spring coil body.

[0012] Preferably, the hydrogel in the hydrogel layer is a thermosensitive hydrogel.

[0013] Preferably, the material of the spring coil body is at least one of platinum-tungsten alloy, platinum-iridium alloy, and stainless steel.

[0014] Compared with the prior art, this utility model can greatly improve the basket-forming properties of the spring coil by inserting a coated extruded filament through the spring coil body, and the coated extruded filament includes a nickel-titanium alloy wire core and a hydrogel layer coated on the nickel-titanium alloy wire core, thereby effectively conforming to the inner wall of the aneurysm cavity, and effectively avoiding the harm of nickel ions to the human body. The structure is simple. Attached Figure Description

[0015] Figure 1 This is a structural diagram of the spring coil in an embodiment of the present invention. At this time, the hydrogel layer has not expanded.

[0016] Figure 2 for Figure 1 Cross-sectional view.

[0017] Figure 3 This is a structural diagram of the spring coil in an embodiment of the present invention. At this time, the hydrogel layer absorbs water and expands.

[0018] Figure 4 for Figure 3 Cross-sectional view.

[0019] Figure 5 This is a structural diagram of the spring coiled into a blue shape according to an embodiment of the present invention.

[0020] Figure 6 This is a structural diagram of the end of the spring coil in an embodiment of this utility model.

[0021] Explanation of reference numerals in the attached diagram:

[0022] 1. Spring coil body; 2. Overcoated extruded filament; 21. Nickel-titanium alloy wire core; 22. Hydrogel layer; 3. Anti-unwinding filament; 4. Ball head; 10. Spring coil. Detailed Implementation

[0023] To explain in detail the technical content, structural features, and effects of this utility model, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0024] like Figures 1 to 6 As shown, this utility model embodiment provides an embolization spring coil 10, including a spring coil body 1 and a coated extruded wire 2. The spring coil body 1 has a hollow structure with openings at both ends to form an inner cavity. The coated extruded wire 2 is inserted into the spring coil body 1. The coated extruded wire 2 includes a nickel-titanium alloy wire core 21 and a hydrogel layer 22 covering the nickel-titanium alloy wire core 21. Both the nickel-titanium alloy wire core 21 and the hydrogel layer 22 extend along the length direction of the spring coil body 1. The nickel-titanium alloy wire core 21 has a shape memory morphology. The austenite transformation completion temperature of the nickel-titanium alloy wire core 21 is greater than or equal to 28 degrees and less than or equal to 32 degrees to recover the shape memory morphology at human body temperature. Specifically, the shape memory form can be a three-dimensional structure. Nickel-titanium alloy has excellent shape memory properties. In the actual manufacturing process, the straight-line coated extruded wire 2 is threaded into the straight-line spring coil body 1 and heat-set together to form the required three-dimensional structure. For example, the straight-line coated extruded wire 2 and the straight-line spring coil body 1 can be wound on a heat-setting mold and heat-treated to form the final required three-dimensional structure. The nickel-titanium alloy wire core 21 exists in the inner cavity of the spring coil body 1. The nickel-titanium alloy wire core 21 recovers its shape memory form at a specific temperature, thereby improving the basketiness of the three-dimensional spring coil 10 by utilizing its excellent shape memory properties. In addition, the spring coil body 1 has a hollow structure and lacks effective internal support. When disturbed by gravity or other factors, it is easy to loosen, reducing basketiness. The hydrogel layer 22 can be made of a hydrophilic polymer mesh structure material, and its water absorption expansion rate can reach 3 to 5 times that of the initial state. When the spring coil 10 is placed in the human body, such as Figure 2 As shown, the hydrogel layer 22 expands rapidly within the spring coil body 1 upon contact with water or blood, filling the inner cavity of the spring coil body 1. This provides strong support for the spring coil 10 and increases the filling density of the aneurysm cavity. Therefore, the combined effect of the nickel-titanium alloy wire core 21 and the hydrogel layer 22 significantly improves the basket-forming properties. Furthermore, as... Figures 1 to 4As shown, the maximum diameter of the expanded hydrogel layer 22 is smaller than the outer diameter of the spring coil body 1, thus preventing the hydrogel layer 22 from affecting the inner wall of the blood vessel during delivery of the spring coil 10. Furthermore, nickel ions are common sensitizing metals and have cytotoxic effects, causing sensitivity in approximately 10% to 20% of the population. The risk of nickel ion release needs to be considered when implanting these metals in the human body. This embodiment of the invention effectively avoids the effects of nickel ions on the human body by coating the nickel-titanium alloy wire core 21 with a hydrogel layer 22, demonstrating a clever design.

[0025] This embodiment of the invention improves the basket-forming properties of the spring coil 10 by inserting a coated extruded wire 2 through the spring coil body 1, wherein the coated extruded wire 2 includes a nickel-titanium alloy wire core 21 and a hydrogel layer 22 covering the nickel-titanium alloy wire core 21, thereby effectively conforming to the inner wall of the aneurysm cavity and effectively avoiding the harm of nickel ions to the human body. The structure is simple.

[0026] In this embodiment of the utility model, such as Figures 1 to 6 As shown, an anti-unwinding wire 3 is also threaded through the spring coil body 1, extending along the length of the spring coil body 1. Specifically, the anti-unwinding wire 3 effectively prevents the spring coil body 1 from unwinding. The anti-unwinding wire 3 can be made of polypropylene (PP). PP anti-unwinding wire 3 has excellent fatigue resistance and high tensile strength, effectively preventing the spring coil body 1 from unwinding. Furthermore, the soft PP wire can always follow the shape changes of the spring coil 10. Simultaneously, the PP anti-unwinding wire 3 facilitates the electrolytic release of the spring coil 10. Electrolytic release refers to melting the pre-set area of ​​the anti-unwinding wire 3 by applying electricity, thereby separating it from the conveying components, etc., which is convenient to operate. Of course, in some other specific embodiments, the anti-unwinding wire 3 can also be made of other materials, such as polyethylene (PE) or polyisoprene (PI). In other specific embodiments, the anti-unwinding wire 3 may not be additionally provided; instead, the covered extrusion filament 2 can be used to provide the anti-unwinding effect. In this case, the release method of the spring coil 10 is mechanical release, which is relatively complex to operate.

[0027] In this embodiment of the utility model, such as Figures 5 to 6 As shown, the ends of the spring coil body 1, the extruded wire 2, and the anti-unwinding wire 3 are connected by ball heads 4. The ball heads 4 cover the ends of the spring coil body 1, the extruded wire 2, and the anti-unwinding wire 3. Specifically, a ball head 4 is provided at each end of the spring coil body 1. The ball heads 4 connect the spring coil body 1, the extruded wire 2, and the anti-unwinding wire 3 into one unit. The ball heads 4 of the spring coil 10 should be round and smooth to avoid damaging blood vessels. The ball head 4 is made of UV adhesive and is formed by UV curing.

[0028] In this embodiment of the invention, the coated extruded filament 2 is disposed in the middle of the spring coil body 1. Specifically, disposing of the coated extruded filament 2 in the middle of the spring coil body 1 facilitates uniform support of the spring coil body 1 after the hydrogel layer 22 expands, resulting in better support. In addition, the anti-unwinding filament 3 is disposed on one side of the coated extruded filament 2.

[0029] In this embodiment of the invention, the hydrogel in the hydrogel layer 22 is a thermosensitive hydrogel. Specifically, the hydrogel needs to be in a fluid state at high temperatures so that it can encapsulate the nickel-titanium alloy wire core 21 for extrusion. After the nickel-titanium alloy wire core 21 and the hydrogel exit the die port of the extruder, they are cooled in a water bath and become solid hydrogels to form the hydrogel layer 22. The nickel-titanium alloy wire core 21 has good biocompatibility and excellent shape memory properties. As those skilled in the art know, different shape memory materials have different austenite transformation completion temperatures Af. By reprocessing materials with a specific Af in subsequent heat treatment processes, Af can be reset to the desired range. This embodiment of the invention adjusts the austenite transformation completion temperature Af of the nickel-titanium alloy wire core 21 to a value greater than or equal to 28 degrees Celsius and less than or equal to 32 degrees Celsius through a heat treatment process. This austenite transformation completion temperature Af, which is 25 degrees Celsius higher than room temperature, ensures that the nickel-titanium alloy wire core 21 is a soft martensitic phase at room temperature, transforming into a highly elastic austenitic phase after implantation into the human body and restoring its shape from the heat-set state. Because the nickel-titanium alloy wire core 21 is a soft martensitic phase at room temperature after heat treatment, this characteristic ensures that it maintains a straight and flexible state during encapsulation extrusion. The hydrogel can specifically be a hydrophilic polymer mesh structure material, and can be selected from existing products on the market according to actual needs; no limitation is imposed here.

[0030] In this embodiment of the invention, the material of the spring coil body 1 is at least one of platinum-tungsten alloy, platinum-iridium alloy, and stainless steel. Specifically, the wire used to make the spring coil body 1 is platinum-tungsten alloy, platinum-iridium alloy, stainless steel, or other materials that are biocompatible and can be visualized under DSA. The spring coil body 1 is formed by tightly winding the aforementioned wire onto a mandrel. The wire diameter of the spring coil 10 is greater than or equal to 0.02 mm and less than or equal to 0.2 mm. After the spring coil body 1 is formed, the mandrel can be removed. The spring coil body 1 needs to have an ideal three-dimensional shape that conforms to the aneurysm cavity wall. The final shape is obtained by fixing the spring coil body 1 on a heat-setting mold and performing heat treatment. The heat treatment parameters vary depending on the selected material and can be selected according to actual needs.

[0031] The above-disclosed examples are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of the present utility model. Therefore, any equivalent changes made in accordance with the scope of the present utility model application shall still fall within the scope of the present utility model.

Claims

1. A spring coil for embolization, characterized in that, The device includes a spring coil body and a coated extruded filament. The spring coil body has a hollow structure with openings at both ends to form an inner cavity. The coated extruded filament is inserted into the spring coil body. The coated extruded filament includes a nickel-titanium alloy wire core and a hydrogel layer covering the nickel-titanium alloy wire core. Both the nickel-titanium alloy wire core and the hydrogel layer extend along the length direction of the spring coil body. The nickel-titanium alloy wire core has a shape memory shape. The austenite transformation completion temperature of the nickel-titanium alloy wire core is greater than or equal to 28 degrees and less than or equal to 32 degrees to recover the shape memory shape at human body temperature.

2. The embolization spring coil as described in claim 1, characterized in that, The hydrogel layer expands and fills the inner cavity of the spring coil body.

3. The embolic spring coil as described in claim 1, characterized in that, The spring coil body is also provided with an anti-unwinding wire, which extends along the length direction of the spring coil body.

4. The embolic spring coil as described in claim 3, characterized in that, The anti-unwinding fiber is made of polypropylene.

5. The embolization spring coil as described in claim 3, characterized in that, The ends of the spring coil body, the covered extruded filament, and the anti-unwinding filament are connected by a ball head, which covers the ends of the spring coil body, the covered extruded filament, and the anti-unwinding filament.

6. The embolization spring coil as described in claim 5, characterized in that, The ball head is made of UV adhesive.

7. The embolization spring coil as described in claim 1, characterized in that, The coated extruded filament is located in the middle of the spring coil body.

8. The embolic spring coil as described in claim 1, characterized in that, The hydrogel in the hydrogel layer is a thermosensitive hydrogel.

9. The embolization spring coil as described in claim 1, characterized in that, The material of the spring coil body is at least one of platinum-tungsten alloy, platinum-iridium alloy, and stainless steel.

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