A coil

Abstract

The present invention discloses a coil, belonging to the technical field of medical devices. The coil includes a coil body, and the coil body includes a support part and a filling part. The support part has a shape memory effect and can adapt to the shape of the opening of the aneurysm sac and support at the neck of the aneurysm sac when expanded; a part of the support part is made of a degradable material, and the other part is made of a non-degradable material; the filling part is filled inside the aneurysm sac, and the filling part is made of a degradable material. The coil of the present invention can reduce the mass effect and can be stably implanted into the aneurysm sac.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a coil Background Art

[0002] An intracranial aneurysm is formed by a local bulge of the arterial wall of a blood vessel. As the aneurysm grows, the compliance of the blood vessel wall decreases and the tension increases, and the aneurysm will rupture. A ruptured aneurysm can cause cerebral vasospasm, disturbance of consciousness, neurological dysfunction, and even death. At present, the surgical methods for intracranial aneurysms mainly include microsurgical clipping, endovascular intervention, extracranial-intracranial artery bypass, coil embolization treatment, etc. Among these numerous solutions, coil embolization treatment has the advantages of safety, reliable implantation, convenient delivery, etc.

[0003] Currently, coils are mainly divided into three types: the first is a preformed bare metal coil, which is made of a platinum-tungsten alloy material preformed into a two-dimensional or three-dimensional structure; the second is a bio-modified coil with a bioactive material covering the surface, which reduces the mass effect by covering a degradable biomaterial on the surface of the metal coil; the third is a highly expandable hydrogel coil, which adds hydrophilic polypropylene hydrogel inside the metal coil. After implantation, the hydrogel absorbs a large amount of water and expands violently in volume, making the coil completely fill the cavity to reduce the recanalization rate of the aneurysm. For the above three types of coils, whether it is a bare metal coil or a bio-modified coil and a hydrogel coil prepared on its basis, although they can treat related diseases after packing, due to the large amount of remaining metal still staying in the body for a long time, problems such as their safety and mass effect have not been completely solved.

[0004] If the coil is made of a degradable material, such as a magnesium alloy coil, the treatment effect will be affected due to the inability to perfectly match the single degradation period and the disease cure period.

[0005] Equally importantly, a coil, as a sac filling device, needs to be kept in the aneurysm for a long time. However, it is difficult to place and maintain a sac filling device in an aneurysm with a large opening, especially for small and relatively thin coils. Before complete embolization is formed in the aneurysm sac, the relatively compliant coils necessarily lack sufficient mechanical strength to resist blood impact to maintain their filling posture in the aneurysm sac, so that they herniate from the aneurysm sac.

[0006] Therefore, there is an urgent need for a coil to solve the above problems. Summary of the Invention

[0007] The purpose of the present invention is to provide a coil that can reduce the mass effect and can be stably implanted in the aneurysm sac.

[0008] To achieve this purpose, the present invention adopts the following technical solutions:

[0009] A coil, comprising a coil body, and the coil body includes:

[0010] A support part, having a shape memory effect, capable of adapting to the shape of the opening of the aneurysm sac and supporting on the neck of the aneurysm sac during expansion; a part of the support part is made of a degradable material, and another part is made of a non-degradable material;

[0011] A filling part, filled inside the aneurysm sac, and the filling part is made of a degradable material.

[0012] In some possible implementation manners, the support part is formed into a net shape by weaving a first woven wire and a second woven wire, the first woven wire is made of a material having a shape memory effect and being degradable, and the second woven wire is made of a material having a shape memory effect and being non-degradable.

[0013] In some possible implementation manners, the first woven wire is formed by electrospinning of a polymer material; and / or, the second woven wire is a nitinol wire; and / or, the filling part is a magnesium alloy wire.

[0014] In some possible implementation manners, the area of the second woven wire accounts for 60%-80% of the total area of the support part, and the first woven wire has elasticity to adapt to the shape of the opening of the aneurysm sac.

[0015] In some possible implementation manners, the support part can expand into an umbrella shape and at least part of the support part supports on the inner wall of the aneurysm sac.

[0016] In some possible implementation manners, it further includes a core wire made of a degradable material, the core wire coincides with the center line of the coil body, one end of the core wire is connected to the proximal end of the support part, and the other end is connected to the distal end of the filling part.

[0017] In some possible implementation manners, a procoagulant drug is provided on the surface of the core wire.

[0018] In some possible implementation manners, a plurality of concave grooves are arranged at intervals in a spiral shape along the length direction on the surface of the core wire, and the procoagulant drug is accommodated in the concave grooves.

[0019] In some possible implementation manners, the depth of the concave groove is h, and the diameter of the core wire is D, wherein, h is 0.3D to 0.6D, and D is 0.05 mm to 0.1 mm.

[0020] In some possible implementation manners, the cross-sectional area of the concave groove near the notch side is not less than the cross-sectional area near the bottom side along the direction from the notch to the bottom of the groove.

[0021] In some possible embodiments, the total volume of the plurality of recessed grooves accounts for 1%-5% of the volume of the coil

[0022] In some possible embodiments, the recessed grooves are formed by plasma etching, and the coagulation-promoting drug is disposed on the core wire that has been plasma-etched.

[0023] Advantages of the present invention:

[0024] A coil provided by the present invention, by providing a coil body including a support portion and a filling portion, during the process of releasing the coil into the aneurysm sac, the filling portion fills the inside of the aneurysm sac, and then continues to push to open the support portion with shape memory effect, so that the support portion expands to a preset state, that is, the support portion adapts to the shape of the opening of the aneurysm sac, blocks the opening and supports the neck of the aneurysm sac, thereby preventing blood flow from flowing into the aneurysm sac to wash the filling portion, preventing the coil from shifting, and can be stably implanted into the aneurysm sac, avoiding the coil herniating from the aneurysm sac before complete embolization is formed.

[0025] Since a part of the support portion is made of a degradable material and another part is made of a non-degradable material, and the filling portion is made of a degradable material. After the coil is implanted, the support portion located at the opening will contact the blood in the blood vessel. Compared with the filling portion in the aneurysm sac, the degradable part of the support portion will degrade relatively quickly to a certain extent, and finally the non-degradable part of the support portion remains to support the neck of the aneurysm sac. On the one hand, the coils remaining in the body are reduced, avoiding problems such as safety and mass effect caused by their long-term stay in the body. On the other hand, the filling portion and part of the support portion are degraded in a gradient to a certain extent, overcoming the problem of too fast degradation, so as to match the disease cure cycle and ensure the treatment effect. Description of the Drawings

[0026] Figure 1 is a schematic diagram of the coil in the state of being transported in the microcatheter provided by the specific embodiment of the present invention;

[0027] Figure 2 is a schematic diagram of the coil in the expanded state in the aneurysm sac provided by the specific embodiment of the present invention;

[0028] Figure 3 is a schematic diagram of the filling portion and the core wire provided by the specific embodiment of the present invention;

[0029] Figure 4 is a schematic diagram of the arrangement of the recessed grooves on the core wire provided by the specific embodiment of the present invention;

[0030] Figure 5 is a schematic diagram of the release of the coagulation-promoting drug when the core wire is in a bent state provided by the specific embodiment of the present invention;

[0031] Figure 6 It is a side schematic view of the concave groove of the core wire provided by the specific embodiment of the present invention;

[0032] Figure 7 is Figure 6 The enlarged view at position A of

[0033] In the figure:

[0034] 1. Spring coil body; 11. Support part; 12. Filling part;

[0035] 2. Core wire; 21. Concave groove; 211. First groove part; 212. Second groove part;

[0036] 3. Coagulant drug;

[0037] 4. Guide wire; 5. Limiting ball; 6. Microcatheter;

[0038] 100. Blood vessel; 200. Tumor sac; 300. Opening. Specific embodiment

[0039] To make the technical problems solved by the present invention, the technical solutions adopted and the achieved technical effects clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present invention.

[0040] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected" and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0041] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but through other features between them. Moreover, the first feature being "above", "above" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "below" and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is lower than that of the second feature.

[0042] As shown Figures 1 - 3 in the figure, this embodiment provides a coil, which includes a coil body 1 and a core wire 2. The core wire 2 is placed inside the coils of the coil body 1. The head and tail ends of the core wire 2 correspond to the head and tail ends of the coil body 1 and are connected and integrated through a welding process or an adhesive technique. The core wire 2 is at the central position of the coil, that is, the core wire 2 coincides with the center line of the coil body 1. The coil is delivered in a blood vessel 100 through a microcatheter 6, and the core wire 2 of the coil is fixed inside the microcatheter 6 by a limiting ball 5. The core wire 2 and the limiting ball 5 are connected by a guide wire 4. When it is delivered to the position of the aneurysm sac 200, the guide wire 4 breaks, so that the limiting ball 5 and the core wire 2 are separated, and the coil enters the aneurysm sac 200. For details, reference can be made to the prior art and will not be elaborated here. By providing the core wire 2, the force on the coil during the delivery stage is made more uniform.

[0043] The coil body 1 includes a support portion 11 and a filling portion 12. One end of the core wire 2 is connected to the proximal end of the support portion 11, and the other end is connected to the distal end of the filling portion 12. The support portion 11 has a shape memory effect and can adapt to the shape of the opening 300 of the aneurysm sac 200 and support on the neck of the aneurysm sac 200 when expanding. Exemplarily, the support portion 11 can expand into an umbrella shape and at least part of the support portion 11 supports on the inner wall of the aneurysm sac 200. A part of the support portion 11 is made of a degradable material, and the other part is made of a non-degradable material. The filling portion 12 fills inside the aneurysm sac 200, and the filling portion 12 is made of a degradable material, such as the filling portion 12 is a magnesium alloy wire.

[0044] Optionally, the support portion 11 is woven by a first woven wire and a second woven wire to form a net. The first woven wire is made of a material with a shape memory effect and is degradable, such as the first woven wire is a polymer filament formed by electrospinning of a polymer material; the second woven wire is made of a material with a shape memory effect and is non-degradable, such as the second woven wire is a nitinol wire.

[0045] Particularly, the area of the second woven wire accounts for 60%-80% of the total area of the support portion 11, that is, the nitinol wire is the main woven wire and the polymer filaments are interspersed therein as auxiliary woven wires. In this hybrid woven structure, the first woven wire, that is, the polymer filaments, provides excellent elasticity and shape memory effect, so that the support portion 11 can adapt to the shape of the opening 300 of the aneurysm sac 200 when expanding, and then more stably support on the neck of the aneurysm sac 200. The polymer filaments with a shape memory effect can be formed by electrospinning of polyurethane or polylactic acid-based polymer materials. The proximal support portion 11 abuts against the inner wall of the aneurysm sac 200 after expansion.

[0046] Optionally, the core wire 2 is made of a degradable material, such as the core wire 2 is made of a magnesium alloy material.

[0047] By setting the coil body 1 including the supporting part 11 and the filling part 12, during the process of releasing the coil into the aneurysm sac 200, the filling part 12 fills the inside of the aneurysm sac 200, and then the supporting part 11 with shape memory effect is continuously pushed to open, so that the supporting part 11 expands to a preset state, that is, the supporting part 11 adapts to the shape of the opening 300 of the aneurysm sac 200, blocks the opening 300 and supports the neck of the aneurysm sac 200, thereby preventing blood flow from flowing into the aneurysm sac 200 to wash the coil, preventing the coil from shifting, and being able to be stably implanted into the aneurysm sac 200, avoiding the coil herniating from the aneurysm sac 200 before complete embolization is formed.

[0048] Since a part of the supporting part 11 is made of degradable material and another part is made of non-degradable material, and the filling part 12 is made of degradable material. After the coil is implanted, the supporting part 11 located at the opening 300 will contact the blood in the blood vessel 100. Compared with the filling part 12 in the aneurysm sac 200, the degradable part of the supporting part 11 will degrade relatively quickly to a certain extent, and then the filling part 12 and the core wire 2 will degrade. Finally, the non-degradable part of the supporting part 11 will remain in the body to support the neck of the aneurysm sac 200, that is, the coil is a gradient degradation embolization treatment device. On the one hand, the coil remaining in the body is reduced, avoiding problems such as safety and mass effect caused by its long-term stay in the body. On the other hand, the filling part 12 and part of the supporting part 11 degrade in a gradient to a certain extent, overcoming the problem of too fast degradation to match the disease cure cycle and ensuring the treatment effect.

[0049] Such as Figures 4 - 7As shown, a coagulation-promoting drug 3 is provided on the surface of the core wire 2, and all or part of the surface of the core wire 2 is covered with the coagulation-promoting drug 3. The coagulation-promoting drug 3 may be one or more of snake venom hemocoagulase, vitamin K, freeze-dried human coagulation factor VIII, prothrombin complex, thrombin, freeze-dried human fibrinogen, aminomethylbenzoic acid, tranexamic acid, aprotinin, and aminocaproic acid, adrenosem and etamsylate. In one embodiment, a plurality of recessed grooves 21 are arranged at intervals in a spiral shape along the length direction on the surface of the core wire 2, and the coagulation-promoting drug 3 is accommodated in the recessed grooves 21. The cross-sectional area of the recessed groove 21 near the notch side is not less than the cross-sectional area near the bottom side along the direction from the notch to the bottom of the groove, such as the recessed groove 21 being in an inverted cone shape. Exemplarily, the recessed groove 21 includes a first groove portion 211 and a second groove portion 212 along the direction from the notch to the bottom of the groove. The first groove portion 211 gradually contracts from the notch to the bottom, and the second groove portion 212 is a groove located at the bottom of the first groove portion 211. Through the arrangement and shape structure design of the recessed grooves 21 on the core wire 2, on the one hand, when the soft core wire 2 is bent and filled with the coil, due to the bending deformation of the core wire 2, the notches of some of the recessed grooves 21 are further expanded, immediately releasing the coagulation-promoting drug 3 into the aneurysm sac 200, so that thrombus is generated in the far area where the coil is not filled, achieving an ideal filling effect with a smaller coil volume. On the other hand, the notches of some of the recessed grooves 21 are squeezed and contracted, playing a role in slow drug release. The coagulation-promoting drug 3 in these recessed grooves 21 mainly relies on blood infiltration to generate thrombus in the near area of the core wire 2 to fix the filling posture of the coil.

[0050] The recessed grooves 21 are made by means of plasma etching, and the coagulation-promoting drug 3 is provided on the core wire 2 that has been plasma-etched. The depth of the recessed groove 21 is h, and the diameter of the core wire 2 is D, where h is 0.3D to 0.6D, and D is 0.05 mm to 0.1 mm, such as 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, or 0.1 mm, etc. Among them, the recessed grooves 21 on the surface of the core wire 2 are realized by methods such as plasma etching. By setting plasma treatment parameters, the depth of the appropriate recessed grooves 21 is controlled, and the etched core wire 2 is immersed in the solution of the coagulation-promoting drug 3 or the recessed grooves 21 are loaded with the drug by spraying. Forming recesses on the surface of the core wire 2 and then covering and loading the coagulation-promoting drug 3 not only overcomes the problem of poor binding force between the drug coating and the surface of the untreated metal wire in the prior art, but also can control the drug loading amount by adjusting the depth and number of the recessed grooves 21, so that the excessive coagulation-promoting drug 3 will not cause harm to the human body. The total volume of the plurality of recessed grooves 21 accounts for 1% - 5% of the volume of the coil.

[0051] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A coil spring, characterized in that, Comprising a coil body (1), the coil body (1) includes: A support portion (11) having a shape memory effect, which can block the opening of the aneurysm sac (200) and support on the neck of the aneurysm sac (200) when expanded; a part of the support portion (11) is made of a degradable material, and another part is made of a non-degradable material; A filling portion (12) filled inside the aneurysm sac (200), the filling portion (12) being made of a degradable material; The coil further includes a core wire (2) made of a degradable material, the core wire (2) coincides with the center line of the coil body (1), one end of the core wire (2) is connected to the proximal end of the support portion (11), and the other end is connected to the distal end of the filling portion (12); a plurality of concave grooves (21) are arranged at intervals in a spiral shape along the length direction on the surface of the core wire (2), and a procoagulant drug (3) is disposed in the concave grooves (21); the cross-sectional area of the concave groove (21) near the notch side is not less than the cross-sectional area near the bottom side along the direction from the notch to the bottom of the groove; After the coil is implanted, the degradable part of the support portion (11) degrades prior to the filling portion (12) and the core wire (2) to achieve gradient degradation.

2. The coil according to claim 1, wherein The support portion (11) is formed into a net shape by weaving a first braided wire and a second braided wire, the first braided wire is made of a material with a shape memory effect and is degradable, and the second braided wire is made of a material with a shape memory effect and is non-degradable.

3. The coil according to claim 2, characterized in that, The first braided wire is formed by electrospinning of a polymer material; and / or, the second braided wire is a nitinol wire; and / or, the filling portion (12) is a magnesium alloy wire.

4. The coil according to claim 2, wherein The area of the second braided wire accounts for 60%-80% of the total area of the support portion (11), and the first braided wire has elasticity to adapt to the shape of the opening of the aneurysm sac (200).

5. The coil according to claim 1, characterized in that, The support portion (11) can expand into an umbrella shape, and part of the support portion (11) supports on the inner wall of the aneurysm sac (200).

6. The coil according to claim 1, wherein, The depth of the concave groove (21) is h, and the diameter of the core wire (2) is D, where h is 0.3D to 0.6D, and D is 0.05 mm to 0.1 mm.

7. The coil according to claim 1, wherein The total volume of the plurality of concave grooves (21) accounts for 1%-5% of the volume of the coil.

8. The coil according to claim 1, wherein The concave groove (21) is made by a method of plasma etching, and the procoagulant drug (3) is disposed on the core wire (2) that has been plasma-etched.

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